Faculty Dr Ramanjaneya Reddy U

Dr Ramanjaneya Reddy U

Associate Professor

Department of Electrical and Electronics Engineering

Contact Details

ramanjaneya.r@srmap.edu.in

Office Location

17, Level 3, SR Block

Education

2017
Ph.D.
National Institute of Technology
India
2012
M.E.
Bangalore University,
India
2009
B.Tech
Jawaharlal Nehru Technological University
India

Personal Website

Experience

  • Nov 2020 - Till date | Assistant Professor | Department of Electrical and Electronics Engineering | SRM University-AP, Andhra Pradesh, India.
  • Apr 2017 – Nov 2020 | Associate Professor | Department of Electrical and Electronics Engineering | Vardhaman College of Engineering, Hyderabad, India (Study Leave from Nov 2017 – Sep 2018).
  • Nov 2017 – Sep 2018 | Post-Doctoral Fellow | Microelectronics Laboratory | University of Crete, Greece.
  • Dec 2013 – Apr 2017 | Senior Research Fellow | Department of Electrical Engineering | National Institute of Technology Warangal, India.
  • Dec 2012 – Dec 2013, | Assistant Professor | Department of Electrical and Electronics Engineering | Chiranjeevi Reddy Institute of Engineering and Technology, Andhra Pradesh, India.

Research Interest

  • Power Electronics - Converters, PWM Techniques, Applications to Lighting System.
  • High Gain Converters for Renewable Energy Applications.
  • Development of control algorithms for converter fed drives.

Awards

  • 2022 - Research Scholar worked under my guidance secured Gold medal (Feb-2022) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2022 - Research Scholar worked under my guidance secured Gold medal (Sep-2022) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2021 - Undergraduate students worked under my guidance secured Gold medal (Aug-2021) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2021 - Research Scholar worked under my guidance secured Gold medal (Aug-2021) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2017 – Received funding for Post Doctoral Fellow – European Government
  • 2015 – Best Paper award at IEEE INDICON Conference – IEEE Delhi Section
  • 2013 – MHRD Fellowship for Doctoral Study – Government of India
  • 2010 – MHRD Fellowship for Masters Study – Government of India

Memberships

  • Senior Member - IEEE
  • Member – Institute of Engineers

Publications

  • Dual Estimation of State of Charge and State of Health of a Battery: Leveraging Machine Learning and Deep Neural Networks

    Avanthika D.S.R.S.L., Udumula R.R., Lokeshgupta B., Morampudi M.K.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    Accurate estimation of battery state including state of charge (SoC) and state of health (SoH) are crucial for ensuring safety in energy storage applications. The SOC and SOH estimators were independently trained using the same input vector but with different objective functions, no integration between SOC and SOH estimations were explored. In this paper, a unified algorithm, for identifying both SoC and SoH states, is introduced by considering the Bayesian optimization for hyperparameter tuning. This approach allows seamless transition between SoC and SoH estimation without needing separate models for each task. In addition, equipping the dual estimation framework with a unified algorithm for identifying both states would impact the algorithm's complexity. The suggested BiLSTM model reduces complexity in real-time Battery Management System (BMS) applications by eliminating the need for a separate model to estimate SoH. When compared to other machine learning and deep learning models such as Support Vector Machines (SVM), Decision Trees (DT), Random Forest (RF), Radial Basis Function Neural Networks (RBF-NN), Recurrent Neural Networks (RNN), and LSTM, the suggested BiLSTM method demonstrates the highest efficiency. Finally, to verify the proposed method's effectiveness, a comparison among the different evaluation metrics was conducted. The proposed BiLSTM model achieved an average MAE (Mean Absolute Error) of 0.08 and NRMSE (Normalized Root Mean Squared Error) of 0.15 for SoC estimation across various temperatures (5°C, 15°C, 35°C, and 45°C), and an MAE of 3.12 and NRMSE of 0.23 for SoH estimation with a degradation rate of 47% of the cell estimated from the predicted capacity values.
  • Power Factor Correction(PFC) for EV Charger Using PI Controller in G2V Application

    Adari J.V., Tewari S.V., Chakravarty A., Udumula R.R., Sagar G.J., Mahto T.

    Conference paper, 1st International Conference on Sustainable Energy Technologies and Computational Intelligence: Towards Sustainable Energy Transition, SETCOM 2025, 2025, DOI Link

    View abstract ⏷

    This paper presents an AC-DC converter system tailored for grid-to-vehicle (G2V) applications, aimed at facilitating efficient power flow while achieving a Unity power factor (UPF). The system employs a rectifier for AC-DC conversion, which effectively steps up a 230V AC input to a 380V DC output. This DC output can be further regulated using a buck converter to meet specific load requirements. A Proportional-Integral (PI) controller is implemented to oversee the voltage and current regulation, thereby minimizing harmonic distortion and enhancing the overall power factor. By actively managing the input voltage and current, the controller ensures that the system operates within desired parameters, thus optimizing power quality. Comprehensive simulation results validate the system's performance, demonstrating its capability to maintain a UPF in G2V mode. The findings indicate significant reductions in total harmonic distortion (THD), reinforcing the system's effectiveness in managing power quality. This AC-DC converter design not only enhances the efficiency of power flow in electric vehicle charging systems but also contributes to the stability of the grid by minimizing reactive power and harmonics. Overall, this work represents a significant advancement in converter technology for sustainable transportation and energy management.
  • Nonlinear Adaptive Neural Control of Power Converter-Driven DC Motor System: Design and Experimental Validation

    Nizami T.K., Gangula S.D., Udumula R.R., Chakravarty A., Ahmad F., Hosseinpour A.

    Article, Engineering Reports, 2025, DOI Link

    View abstract ⏷

    This article presents an intelligent adaptive neural control scheme to track the output speed trajectory in power converter-driven DC motor system. The proposed technique integrates an adaptive polynomial-neural network with a backstepping strategy to yield a robust control system for output tracking in DC motor. Such a unification of online neural network-based estimation and adaptive control, results in effective regulation of the output across a wide load torque uncertainties, besides yielding a promising transient and steady-state performance. The stability of the entire closed-loop system is ensured through Lyapunov stability criterion. The efficacy of the proposed strategy is revealed through an extensive experimental investigation under various operating points during start-up, step-reference tracking, and external step-load torque disturbances. The real-time experimentation is conducted on a laboratory prototype of power converter-driven DC motor of 200 W, using dspace DS1104 control board with MPC8240 processor. The results obtained confirm an improvement in the transient response of the output speed by significantly reducing the settling time to (Formula presented.) and yielding a steady state behavior with no peak over/undershoots during load disturbances, in contrast to other similar works presented in the literature intended for same the application.
  • Zernike radial basis neural network control of DC–DC power converter driven permanent magnet DC motor: design and experimental validation

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A., Ahmad F.

    Article, Electrical Engineering, 2025, DOI Link

    View abstract ⏷

    This article presents a novel control architecture for an enhanced closed-loop speed tracking of a DC–DC buck power converter fed Permanent Magnet DC motor (PMDC) motor in face of large exogenous load torque uncertainty. The proposed architecture combines a new self learning Zernike radial polynomial neural network (ZRNN) estimator with the backstepping controller. The design involves a computationally simple online learning based ZRNN to rapidly and accurately estimate the unknown large load torque uncertainties. The proposed control solution concurrently guarantees stability and excellent dynamic performance through an effective neural network based estimation and subsequent compensation of unanticipated load torque perturbations over a wide range. The closed loop stability of the DC–DC buck power converter driven PMDC motor and asymptotic speed tracking with the proposed neuro-adaptive controller is proved using the stability theory for non-autonomous systems. The effectiveness of the proposed controller has been investigated through experimentation on an indigenously developed laboratory prototype of 200 W under closed loop operation using digital signal processors. The tests conducted around different operating conditions include the motor start-up response, step variations in the load torque, and step changes in the reference speed. Experimental results demonstrate a significant improvement in the speed tracking performance achieving 48.13% reduction in the settling time and no-change in speed during start-up and load torque perturbations upto 600%, respectively. Experimental validations and extensive tests spanning over a large operating region, substantiate the theoretical claims and real-time suitability of the proposed controller for sensitive applications demanding high performance.
  • Non-isolated High-Gain DC-DC Converter with Moderate Gain for Hybrid Energy System Applications on DC Microgrids

    Vijayan M., Ramanjaneya Reddy U., Mahto T.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    A novel non-isolated High-Gain DC-DC Converter with Moderate Gain for Hybrid Energy System applications on DC Microgrids. The paper proposes a novel high-gain DC-DC converter for Hybrid energy systems such as Solar Photovoltaic (PV) systems, Fuel cells (FC), etc. The converter can replace the necessity of multiple converters for multiple sources. The major contributions are the lower switch voltage stress, High boost gain, multiple input capability, and lower component count as a dual source capability. The design and analysis of ideal and non-ideal conditions of the components are discussed and the individual effects of each component are analyzed. Further, the non-ideal gain and non-ideal efficiency are derived and presented. Also, Simulation results with a rated power of 100W are presented.
  • A Novel High Gain Tertiary Port Boost Converter for Hybrid Energy System Integration

    Vijayan M., Udumula R.R., Mahto T.

    Article, IEEE Transactions on Consumer Electronics, 2025, DOI Link

    View abstract ⏷

    This paper introduces novel high-gain tertiary port boost converter (HGTPBC) designed for hybrid energy sources such as solar photovoltaic (PV) and fuel cells (FC). The converter is employed with dual input sources by facilitating modular converters and accomplishes a high step-up voltage gain by virtue of a voltage multiplier in a DC microgrid, where the prosumers can have an islanded operation. The proposed topology allows home appliances to be powered by multiple energy source without the need for a large storage unit. Key features include continuous input current, reduced normalized voltage stress on switches, expandability for multiple input sources and independent source control. The independent control facilitates the standalone operation with single source during source failure or absence. To evaluate the converter performance, a thorough steady-state analysis, both with and without consideration of nonidealities is carried out. Detailed comparisons with existing converter topologies highlight the advantages of the proposed converter. Moreover, the loss distribution and efficiency analysis of proposed converter are presented and found to be 91.59% efficiency at rated power. Theoretical aspects are validated through hardware testing on a 100W laboratory prototype.
  • Development of bi-directional switched-capacitor DC-DC converter for EV powertrain application

    Mounika Nagabushanam K., Mahto T., Tewari S.V., Udumula R.R., Alotaibi M.A., Malik H., Ustun T.S.

    Article, Engineering Science and Technology, an International Journal, 2025, DOI Link

    View abstract ⏷

    The research presents a novel Bidirectional Switched Capacitor DC-DC (BSCD) Converter and demonstrates its application in integrating a battery with an electric vehicle's (EV) traction motor. During discharging, the motor is powered by the battery through the converter, and during charging, the traction motor functions as a generator, returning the recovered energy to the battery via the converter. The recommended converter employs a two-duty cycle operation to enhance voltage gain while minimizing circuit components. It utilizes a switched capacitor (SC) cell, enhancing the voltage transfer ratio by operating capacitors CS1 and CS2 in parallel or series. The work includes analysis of the converter's steady state, mathematical approach, state-space modelling, stability, and efficiency. The proposed converter achieves an efficiency of 90.66 % in charging mode and 96.6 % in discharging mode, with a Gain Margin of 54.4 dB and Phase Margin of 8.09°, indicating stability. Comparative evaluations with existing BDCs are also provided. The implementation of a closed-loop simulation using MATLAB/Simulink and dSpace software validates the performance of the suggested converter-based drive. Furthermore, an experimental investigation of a 200 W, 30 V/430 V configuration confirms the converter's practical viability.
  • Zero voltage switching with reduced current stress for LED lighting applications

    Rao K.V.G., Kumar M.K., Goud B.S., Udumula R.R., Reddy C.R., Balachandran P.K., Zainuri M.A.A.M., Ramasamy S.

    Article, IET Power Electronics, 2025, DOI Link

    View abstract ⏷

    Lighting systems using light emitting diode (LED) have drawn significant attention across the world. Nevertheless, to maintain a steady light output, these systems necessitate constant current regulators. This article proposes a buck–boost integrated zero voltage switched full-bridge LED converter with low current stress. It powers two identical lamps and a lamp of power rating twice the identical lamp. A direct current voltage source, arranged in series, transmits a portion of light power without conversion. A regulated low power output is provided using a complete bridge converter. The semiconductor switches off the full-bridge converter carry minimal current. This characteristic lowers conduction losses. The suggested converter facilitates dimming operation via on–off control and zero voltage switching, leading to minimal switching losses. Further input voltage of full-bridge converter is modulated to maintain constant LED lamp current. The detailed steady-state analysis and implementation of the proposed full-bridge LED converter with dimming control operation is presented here.
  • Random Forest based Machine Learning Algorithm for Estimating State of Charge in Lithium-ion Batteries

    Avanthika D.S.R.S.L., Lokeshgupta B., Udumula R.R.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    This paper proposes a Random Forest (RF) machine learning algorithm-based prediction model for the state of charge (SoC) level of lithium-ion batteries for electric vehicles. To show the effectiveness of the proposed prediction model performance, the RF model has been compared with the other machine learning algorithms such as Support Vector Machines (SVM) and Gradient Boosting (GB) approaches. The dataset includes cell temperature, state of charge (SoC), voltage, and current readings at three different external temperatures-15, 25, and 30 degrees Celsius are considered in this paper to test the performances of the proposed model. After preprocessing of the dataset, 20% of the data was used for testing and the remaining 80% for training purposes. The various metrics such as mean squared error (MSE), mean absolute error (MAE), coefficient of determination (R2), root mean squared error (RMSE), normalized root mean squared error (NRMSE), residual standard error (RSE), and relative absolute error (RAE) are usually preferred to evaluate the performance of the prediction models. The simulation results of the proposed model clearly show the effectiveness of SoC-level estimation for real-time battery management systems (BMS) when compared to other machine learning algorithms. The efficiency of the proposed model is 99% and execution time is less than 5 seconds. The accurate estimation of the SOC of lithium-ion batteries is crucial for optimizing battery performance, ensuring safety, and extending battery life in electric vehicles.
  • Real Time Implementation of Buck Converter Using Optimized Type Compensators

    Gangula S.D., Mukhtar A., Nizami T.K., Chakravarty A., Udumula R.R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This work investigates the application of Artificial Bee Colony (ABC) optimization for the design of Type compensators utilizing the dual-loop control scheme. The proposed Type compensators integrate the ABC optimization for regulating the closed-loop operation of a DC-DC buck converter. Such an integration of ABC optimization, aids in effectively regulating the output voltage and inductor current, besides ensuring enhanced time domain criteria. The proposed dual-loop control scheme consists of a current loop and a voltage loop. The current loop regulates the inductor current and the voltage loop regulates the output voltage. The efficacy of the proposed method is revealed through extensive simulation and experimental investigation under start-up response, step perturbations in external load. The experimentation is conducted on a laboratory prototype using dspace DS1104 control board.
  • Self-learning Controller Design for DC–DC Power Converters with Enhanced Dynamic Performance

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A.

    Article, Journal of Control, Automation and Electrical Systems, 2024, DOI Link

    View abstract ⏷

    This article presents a promising self-learning-based robust control for output voltage tracking in DC–DC buck power converters, particularly for applications demanding high precision performance in face of large load uncertainties. The design involves a computationally simple online single hidden layer neural network, to rapidly estimate the unanticipated load changes and exogenous disturbances over a wide range. The controller is designed within a backstepping framework and utilizes the learnt uncertainty from the neural network for subsequent compensation, to eventually ensure an asymptotic stability of the tracking error dynamics. The results obtained feature a significant improvement of dynamic and steady-state performance concurrently for both output voltage and inductor current in contrast to other competent control strategies lately proposed in the literature for similar applications. Extensive numerical simulations and experimentation on a developed laboratory prototype are carried out to justify the practical applicability and feasibility of the proposed controller. Experimental results substantiate the claims of fast dynamic performance in terms of 94% reduction in the settling time, besides an accurate steady-state tracking for both output voltage and inductor current. Moreover, the close resemblance between computational and experimental results is noteworthy and unveils the immense potential of the proposed control system for technology transfer.
  • Power Factor Correction Buck-Boost Converter for On-Board EV Charging Application

    Udumula R.R., Patnaik S., Nandigama S.K., Dega U.S., Lokeshgupta B., Vemula N.K., Kirankumar N.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    This work presents the power factor correction (PFC) buck-boost converter for on-board electric vehicle (EV) charging applications. The PFC buck-boost converter is designed to operate in discontinuous current conduction mode (DCCM), thus achieving natural PFC for the universal input voltage range. In addition, DCCM operation does not require input voltage or current sensors; as a result, the control is more reliable and economical than continuous current conduction mode (CCCM). Furthermore, the buck-boost converter switch operates in zero current switching (ZCS) which results in reduced switching losses and improves the efficiency. The detailed steady-state analysis, operating modes, and design analysis for DCCM operation are presented. To validate the theoretical studies, a closed-loop voltage mode control of the PFC buck-boost converter is developed and tested in a PSIM software environment. The simulation results uphold the converter analysis and achieve a high power factor and low total harmonic distortion (THD) for the universal input range.
  • A Novel PWM Inverter Powered by Single DC Source for a Multiple Pole Pair Induction Motor

    Nallamekala K.K., Reddy U.R., Mishra P., Vemula N.K., Krishna A.R.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    In this paper, a customized multi-level inverter configuration designed for driving an induction motor with multiple pole pairs is introduced. Within the induction motor, each pole pair winding coil spaced 360° (electrically) apart maintains the same voltage profile. In our case, two windings in a four-pole induction motor are deliberately disconnected. A dual two-level inverter is used to power each half of the winding, so two such inverters are used to feed the entire stator winding of the induction motor as pole pair windings are disconnected. The single DC source used to power these inverters has a magnitude of Vdc/4, or 25% of input voltage DC bus voltage needed to power a typical Neutral Point Clamped five-level inverter. This new Pulse Width Modulation approach is used to cancel the harmonics at first center band while controlling the inverter output voltage. This method successfully lowers torque ripple by reducing current ripple. Furthermore, power balancing problems are eliminated because the single DC source is supplying the entire topology. The capacitor voltage balancing problems are also resolved because this design is derived using only two-level inverters. Very few changes to the design are needed for the suggested topology; the main change is to disconnect winding coils with the same voltage profile. The efficacy of the proposed inverter employing the innovative PWM technique in the linear modulation region is demonstrated by simulation results utilizing a 5-hp four-pole induction motor in MATLAB (Simulink).
  • Independently Controllable Single-Input Dual-Output DC-DC Converter for DC Microgrid Based PV Fed EV Charging Stations

    Vijayan M., Ramanjaneya Reddy U., Mahto T., Narasimharaju B.L., Dogga R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    A new non-isolated single-input dual-output (NI-SIDO) DC-DC converter is proposed in this paper. The converter has the advantage of incorporating multiple outputs for energy storage applications, applicable in DC micro-grid storage systems, Electric vehicular charging stations, battery converters, and renewable energy systems without a filter capacitor. The significant advantage of the converter is it uses the interleaving technique to incorporate the outputs. The voltage stress across the switches and capacitor voltage stress is also reduced drastically. Thus it reduces the capacitor size when compared with the conventional boost converter. A closed-loop control strategy is implemented to control the load voltage as well as the inductor current. The converter is designed, analyzed, implemented, and tested using MATLAB SIMULINK software for 150W. The Simulation results are presented under various operating conditions such as changes in load with solar PV systems. The results from real-time testing are presented with the OPAL-RT system.
  • Control Implementation of BKY Converter for EV Applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Ramanjaneya Reddy U.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This paper proposes BKY converter, which is made to run in continuous conduction mode during both the charging and discharging cycles for low power EV applications. An analysis is conducted on the converter's dynamic behavior, and an approach to control is put forth to manage the power transfer between the traction system and battery in an electric vehicle. The suggested converter is designed using an extracted small-signal model. A significant ripple in the detected current causes switching instability in the current-mode control approaches at low duty ratios. A computation delay occurs when the controller is implemented in the microcontroller. The control algorithm's design takes this into account. A theoretical framework for current and voltage loop gain transfer functions are created using the realistic parameters of a BKY converter. Further, dynamic performance under load variations is explained and validated by simulations.
  • Dynamic Operation of Islanded DC Microgrid with Fuel Cell Using Hybrid Energy Storage Systems

    Vijayan M., Udumula R.R., Mahto T., Bhamidi L.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    Effective utilization of renewable energy sources (RES) is with the better management of their fluctuation nature. Employing hybrid energy storage systems (HESS) in line with the RES will improve the power flow equilibrium in the DC microgrids (DC-MG). In this paper, a PI control-based hybrid energy storage system with a Proton exchange membrane (PEM) fuel cell (FC), battery, and a supercapacitor (SC) for increasing the effectiveness of renewable power in the DC-MG is presented. A validation test is conducted for a 100 W DC microgrid system to verify the effectiveness of the proposed model. The MATLAB/SIMULINK software is used to implement the proposed system.
  • Modified Switched Capacitor-Based Non-isolated Bidirectional DC–DC Converter for Obtaining High VTR

    Nagabushanam K.M., Tewari S.V., Udumula R.R., Mahto T.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    Energy storage systems with a high voltage transfer ratio (VTR) play an important role in integrating modern electric power systems with large-scale renewable energy integration. This article suggests a modified Switched Capacitor non-isolated Bidirectional DC–DC Converter (SCBDC) topology to achieve a high VTR. The presented converter has a simple circuit, simple control, a switched capacitor structure that increases the voltage-gain range, and low-voltage stress on switches, making it suitable for renewable and hybrid energy source electric vehicle applications. Continuous conduction mode is used for the operation principles, steady-state analysis, and extraction of voltage and current equations. Simulation results for the proposed converter were obtained in a MATLAB environment, demonstrating the converter's feasibility.
  • Development of high-gain switched-capacitor based bi-directional converter for electric vehicle applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Udumula R.R., Alotaibi M.A., Malik H., Marquez F.P.G.

    Article, Journal of Energy Storage, 2024, DOI Link

    View abstract ⏷

    High efficiency, high voltage transfer ratio (VTR), and low input ripple current is required in any bidirectional DC-DC converter (BDC) that plays a major role in interfacing batteries in applications like dc microgrids and electric vehicles (EVs). For meeting these requirements, a switched capacitor-based BDC is proposed to interface the battery with a propulsion system via DC Link. It has a simple circuit with only a set of switching operations, High VTR, and lesser ripple current on the low voltage (LV) side are advantages of the proposed High Gain Switched-Capacitor Bi-directional DC-DC Converter (SC-BDC) making it appropriate for use in EVs. The steady-state analysis, design consideration of passive components, loss and efficiency analysis are presented. Finally, the proposed High Gain SC-BDC is compared with few of the existing BDC in the literature. The feasibility of the converter was demonstrated by simulating a 200 W converter and validating results produced in a MATLAB environment.
  • A novel multi-port high-gain bidirectional DC–DC converter for energy storage system integration with DC microgrids

    Vijayan M., Udumula R.R., Mahto T., K.M. R.E.

    Article, Journal of Energy Storage, 2024, DOI Link

    View abstract ⏷

    Bidirectional converters have often been used in numerous applications like DC microgrids, renewable energy, hybrid energy storage systems, electric vehicles, etc. The paper proposes a novel multi-port high-gain (NMPHG) bidirectional DC–DC converter that supports DC microgrid (DC-MG) applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, multiple input ports, lower switch voltage stress, and lower component count owing to the single converter with multiple input ports for DC microgrid applications. The detailed operational principle, analysis, and design considerations of proposed NMPHG bidirectional DC–DC converters are discussed. Furthermore, the loss analysis, detailed comparison with similar works, and efficiency analysis with non-modalities during forward power flow (LV to HV) and reverse power flow (HV to LV) modes are presented. The efficiency of the proposed converter is found to be 93.8% in forward power flow and 92.9% in reverse power flow modes at rated power. Finally, a hardware prototype of the proposed NMPHG bidirectional DC–DC converters is implemented with 100 W in FPF mode and 200 W in RPF mode with a TMS320F28335 processor and validated with theoretical counterparts.
  • A comparative analysis of non-isolated Bi-directional converters for energy storage applications

    Nagabushanam K.M., Tewari S.V., Udumula R.R., Mahto T.

    Review, Engineering Research Express, 2024, DOI Link

    View abstract ⏷

    Bi-directional DC-DC converters (BDC) are required for power flow regulation between storage devices and DC buses in renewable energy based distributed generation systems. The fundamental requirements of the BDC are simple structure, reduced switching components, a wide range of voltage gain, low voltage stress, high efficiency, and reduced size. There are different BDC topologies for various applications based on their requirements in the literature. Various BDC are categorized according to their impedance networks. Isolated BDC converters are large due to high-frequency transformers and hence used for static energy storage applications whereas non-isolated BDC is lightweight and suitable for dynamic applications like electric vehicles. This paper reviews types of non-isolated BDC topologies. The performance of five non-isolated BDC converters under steady state condition is evaluated by using theoretical analysis. On this basis, suitability of BDC for different applications is discussed. Further advantages and limitations of converters are discussed by using comparative analysis. The optimization of BDC for distributed generation systems from the perspectives of wide voltage gain, low electromagnetic interference, low cost with higher efficiency is identified. Theoretical analysis of the converters is validated by simulating 200W converters in MATLAB Simulink.
  • High gain Bi-directional KY converter for low power EV applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Udumula R.R.

    Article, Energy, 2024, DOI Link

    View abstract ⏷

    In electric vehicles (EVs), the type of electric motor and converter technology have a significant impact on regulating the operational characteristics of the vehicle. Therefore, in this work, the modified bi-directional KY converter (BKYC) is proposed for EV applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, bi-directional power flow, simplified control structure, continuous current, common ground, low volume, and high efficiency. An inductor on either side of the converter ensures continuous current flow and passive components are arranged to operate in series to offer high step-up/step-down conversion. The charging and discharging operations, steady-state analysis, and design process of the proposed converter are discussed in detail and compared with similar bi-directional converter topologies. Further, the efficiency analysis of the proposed converter is presented and found that the efficacy of 95.51 % in charging operation and 96.52 % in discharging operation of operation. The simulations are carried out using MATLAB/Simulink environment. Further, a prototype of a modified bi-directional KY converter is implemented with a TMS320F28335 processor and validated with theoretical and simulation counterparts.
  • Switched Reluctance Motor-based EV Drive with Bidirectional Grid Interaction

    Keshari A., Raveendhra D., Raju B.L.N., Chaturvedi P., Reddy U.R., Bobba P.B.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This manuscript presents a novel Multi-function Switched Reluctance Motor (SRM) based Electric Vehicle (EV) Drive system with integrated Grid-to-Vehicle (G2V) & Vehicle-to-Grid/ Vehicle-to-Load (V2G/V2L) functionalities. The study focuses on the development of a Hybrid Energy Storage System (HESS) that combines the advantages of batteries and super-capacitors to enhance the overall performance and efficiency of EVs. The work begins by discussing the design and integration of the SRM drive system, highlighting its ability to provide multi-functionality while maintaining high levels of efficiency and reliability. The integration of G2V and V2G/V2L functions further enhances the flexibility and usability of the system, allowing for bidirectional power flow between the vehicle and the grid or other loads. One of the key contributions of this work is the development of a comprehensive model for the HESS, which takes into account the characteristics of both the battery and super-capacitor components. This model serves as a universal framework for evaluating different HESS configurations and optimizing their performance based on specific application requirements. The paper also discusses the extensive testing and analysis conducted to validate the proposed HESS system. Results demonstrate the high degree of efficiency achieved by the system, leading to extended battery life and improved overall energy management in EVs. Moreover, the HESS model proves to be versatile, offering insights into power characteristics and aiding in the customization of battery configurations and controller settings.
  • Bidirectional AC-DC Converter System for Grid-to-Vehicle and Vehicle-to-Grid Applications

    Revanth Sai R., Hemanth Kumar M., Dual M.A., Lakshmi S., Tewari S.V., Udumula R.R.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    This paper presents a bidirectional AC-DC converter system designed for seamless power exchange between electric vehicles (EVs) and the utility grid. The proposed converter facilitates the conversion of 230 V, 50 Hz AC input to 380 V DC during grid-to-vehicle operation, allowing for efficient battery charging through a bidirectional DC-DC converter. Conversely, during vehicle-to-grid operation, it converts the 380 V DC input from the DC-DC converter to 230 V, 50 Hz AC output for grid supply. The system employs PI controllers to ensure precise voltage and current regulation, ensuring stable and efficient operation during grid interaction. Simulation results demonstrate the system’s effectiveness in managing power conversion for both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) applications.
  • A Novel Zero Voltage Switching Full Bridge Converter for Multiple Load Battery Fed LED Driver Applications

    Patakamoori A., Udumula R.R., Nizami T.K., Reddy Ch K.R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    A novel zero-voltage switching full-bridge (NZVSFB) converter designed for multiple load LED driver applications is introduced in this paper. Four LED lamps are involved in this configuration, with Lamp-2, Lamp-3, and Lamp-4 being powered by a full bridge converter, and Lamp-l being directly connected in series with the battery source. The efficiency of the system is increased since the power provided to lamp-l comes directly from a battery source, eliminating the need for any power processing stage. The major claims of the proposed NZVSFB converter are low component count/lamp, enhanced efficiency, zero voltage switching (ZVS) of all the switching devices, ripple free current and equal current sharing. The interleaved technique utilized in inductor design aims to mitigate the adverse effects of ripple currents on LED performance and circuit reliability by reducing their magnitude and ensuring more stable operation. The steady state operation of the proposed NZVSFB converter is discussed in detail and the effectiveness of the circuit is verified in MATLAB Simulink environment.
  • Smart Home Energy Management with a Coordinated Neighborhood Energy Sharing

    Ravivarma K., Lokeshgupta B., Ramanjaneya Reddy U.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    The rapid increase in demand for electricity and the emergence of the smart grid have dealt with optimistic opportunities for home energy management systems. The smart home with the integration of renewable energy sources such as photovoltaic systems, micro-wind turbines, and battery storage can provide in-house power generation and also give the option of exporting power to the grid. This paper mainly proposes a centralized coordinated neighborhood power-sharing with incentive-based energy management for multiple smart home consumers. The incentive method and various pricing schemes like time of use and feed-in tariff are considered in this paper to determine the electricity billing of all smart home consumers. Due to these incentives and pricing schemes in this model, all smart home consumers are encouraged to be involved in neighborhood energy sharing. A group of ten smart homes with various load profiles and RER energy integration is considered as a test system to determine the performance of the proposed neighborhood smart home energy management model. The simulation results show that the centralized neighborhood-coordinated smart home energy management model can provide significant economic benefits to all smart home consumers when compared to the without neighborhood power-sharing case.
  • Experimental Investigation on Backstepping Control of DC-DC Buck Converter Fed Constant Power Load

    Gangula S.D., Nizami T.K., Udumula R.R.

    Conference paper, IFAC-PapersOnLine, 2024, DOI Link

    View abstract ⏷

    In contemporary energy production, there's been a significant transition from coal-centric methods to renewable energy sources (RES) that emit zero pollutants. As RES becomes more integral to expansive power systems, there's a growing need for regulated power electronic systems. When integrated with microgrids, RES often face stability challenges, being represented in DC microgrids as a constant power load (CPL). The DC-DC converters designed to operate these CPL loads are affected by switching irregularities and the destabilizing effects of CPL, leading to broader power system instability. This study introduces a backstepping control (BSC) approach for a DC-DC buck converter operating with CPL. Through extensive experimental investigations, the effectiveness of the proposed controller under various test conditions, contrasting its results with the cascade PI controller have been evaluated. The outcomes reveal that the proposed backstepping control technique enhances both the dynamic and steady-state performance of the DC-DC buck converter-CPL system, especially during extensive fluctuations in the load power.
  • A Three Leg Asymmetrical Voltage Resonant Converter With Independent Dimming Control for Multiple Load LED Lighting Applications

    Udumula R.R., Vijayan M., Reddy C.K.R., Syed M., Patakamoori A., Gopichand B.

    Article, IEEE Transactions on Industry Applications, 2024, DOI Link

    View abstract ⏷

    LED lighting has emerged as a global solution for sustainable industrial lighting. The three-leg asymmetrical voltage resonant converter has been designed for optimal performance in dimmable Light-emitting diode (LED) lighting applications. Its distinctive features, including enhanced efficiency, asymmetrical voltage regulation, Zero Voltage Switching (ZVS) of all power switches, and an independent dimming control strategy, make it well-suited for high-power LED lighting applications. The converter under consideration incorporates a common leg-1 to drive load-1 and load-2. So that, the load-1 and load-2 are powered by the asymmetrical voltage between leg-1 and leg-2, and leg-1 and leg-3 respectively. To enable independent dimming control, the voltages between legs are nullified by individual dimming levels. The proposed circuit incorporates two resonant circuits. This configuration ensures that all power switches operate with ZVS, effectively minimizing switching losses. Further, the threshold voltage of each LED load is supplied by the battery in turn resulting in a lower power processing of the converter. The detailed operational principle and design considerations are discussed. Moreover, the loss analysis, detailed comparison with similar works, and the efficiency analysis at different dimming conditions are presented. Finally, the effectiveness of the converter is verified in a MATLAB Simulink environment and an 80W laboratory prototype.
  • Adaptive neural network control of DC–DC power converter

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A., Singh P.

    Article, Expert Systems with Applications, 2023, DOI Link

    View abstract ⏷

    This article proposes a novel Zernike radial neural network based adaptive control architecture for closed-loop control of output DC voltage in DC–DC buck power converter. The proposed combination of novel Zernike radial neural network estimator and the adaptive backstepping controller effectively compensates for wide range of perturbations affecting the converter system, in an online manner. The closed loop stability of the DC–DC buck power converter with the proposed neuro-adaptive backstepping controller is shown using Lyapunov stability criterion. Numerical simulations are conducted to examine the effectiveness of the proposed controller under start-up response and step changes in the load, source voltage and reference output voltage. Furthermore, the simulation findings are validated by conducting extensive real-time investigation on a laboratory prototype, under a wide range of operating points. The results obtained show a significant improvement in the transient response of both output voltage and inductor current of the converter, relative to the relevant control methods proposed in the recent past.
  • Comparative Analysis of Resonant Converter Topologies for Multiple Load Light Emitting Diode Applications

    Patakamoori A., Udumula R.R., Nizami T.K., Meesala R.E.K.

    Conference paper, Lecture Notes in Electrical Engineering, 2023, DOI Link

    View abstract ⏷

    The Light Emitting Diodes (LEDs) are gaining more importance in several lighting applications due to their advantages, such as high efficiency, long life, and environment friendliness, over conventional lighting sources. The driver circuit is a significant component in an LED lighting system to provide regulated power to the lamp. Numerous, DC-DC converter topologies have been proposed for LED lighting applications. Under which low- and medium-power lighting applications such as domestic lighting, traffic lighting, and decorative lighting, non-isolated driver circuits are more beneficial. However, in high-power applications such as street lighting and industrial lighting, isolated and soft switching converters are mostly used as LED driver circuits. Due to high-power capability, reduced switching losses, less component count, high frequency of operation, and high efficiency, soft switching converters are drawing more attention in high-power applications. This paper presents a comparative analysis of resonant LED driver topologies proposed for multiple load lighting applications. Simulations of a few full bridge LED driver topologies have been carried out using MATLAB/Simulink environment. Various performance parameters are evaluated, and finally, conclusions are drawn.
  • Enhanced Predictive Torque Control of Open Winding Permanent Magnet Synchronous Motor Drive with Common Mode Voltage Elimination

    Meesala R.E.K., Athikkal S., Ramanjaneya Reddy U., Kedika N.R.

    Book chapter, Lecture Notes in Electrical Engineering, 2023, DOI Link

    View abstract ⏷

    Nowadays, Predictive Torque Control (PTC) strategy is recognized as a strong tool for controlling the motor drive. Intuitive and multi-objective controlling are significant benefits of PTC. Owing to these benefits, its application is introduced for Open Winding Permanent Magnet Synchronous Motor (OW-PMSM) drive. The basic PTC operated OW-PMSM drive consequences high Common Mode Voltage (CMV) and leads to early failure of motor bearings. In this paper, CMV elimination is proposed for OW-PMSM drive using voltage vector selection in PTC operation. In proposed PTC, the possible voltage vectors (VVs) are identified to gain zero CMV and preselected as prediction VVs for cost-function evaluation. From cost-function evaluation, optimal VV is considered for controlling OW-PMSM drive. In addition, decrease in switching frequency is achieved through proper utilization of optimal VV’s redundant switching states. Therefore, the overall modifications in proposed PTC of OW-PMSM drive ensure simple operational control, CMV elimination, and switching frequency and loss reduction. The claims of proposed PTC are verified through Matlab/Simulink platform and its proficiency is highlighted against basic PTC operation. Thus, the enhanced operation of proposed PTC for OW-PMSM drive with zero CMV is justified.
  • Real-Time Implementation of Laguerre Neural Network-Based Adaptive Control of DC-DC Converter

    Gangula S.D., Nizami T.K., Ramanjaneya Reddy U., Singh P.

    Conference paper, Lecture Notes in Networks and Systems, 2023, DOI Link

    View abstract ⏷

    Applications of power electronic converters have increased invariably in fields of engineering such as robotics, e-mobility and smart grids. DC-DC converters are employed as a switching devices to obtain a required amount of DC voltage in various industrial applications. Under the class of non-isolated DC-DC power converters, the buck converters are of specific interest, as they provide lower DC output voltage than the source DC voltage. In order to obtain a faithful output voltage tracking despite disturbances affecting the system, the converter is connected in the closed feedback loop. In this respect, this paper presents the design, development and experimental findings of Laguerre neural network driven adaptive control of DC-DC buck power converter. The stability of the proposed controller is established through Lyapunov stability criterion. Further, the results are compared with adaptive backstepping control method, by subjecting the converter to start-up test, step changes in the load resistance, input voltage and reference voltage tests. Thereafter, the performance is evaluated on DSP-based dSPACE 1104 processor in the laboratory. Finally, the results are compared in terms of settling time of output voltage state. The results indicate an enhanced dynamic performance of both output voltage and inductor current with the action of proposed controller, thus making it suitable for fast practical applications.
  • Three-Leg Asymmetrical Voltage Resonant Converter for Multiple LED Load Applications with Independent Dimming Control

    Syed M., Gopichand B., Reddy Udumula R., Kasi Ramakrishna Reddy C.

    Conference paper, 2023 IEEE IAS Global Conference on Emerging Technologies, GlobConET 2023, 2023, DOI Link

    View abstract ⏷

    In this paper a new three-leg asymmetrical voltage resonant converter is proposed for multiple LED load applications. The converter is developed with leg-1 has common for both LED loads. The main contributions of the proposed work are: (1) Independent dimming control of LED loads, (2) Zero Voltage Switching (ZVS) of all the power switches, (3) High efficiency and (4) Regulation with asymmetrical voltage control. To achieve independent dimming control, the PWM dimming is employed with leg-2 and leg-3. Two resonant circuits are connected in the proposed circuit. Owing to this all the power switches operate with zero voltage switching which reduces the switching losses, resulting in higher converter efficiency. The loads can be regulated using asymmetrical voltage control. The threshold voltage for the LED loads is supplied with battery source, therefore power processing of converter is reduced. The operating modes and steady-state analysis of the proposed converter are presented in detail and verified by using the MATLAB Simulink environment.
  • Soft-switched full-bridge converter for LED lighting applications with reduced switch current

    Patakamoori A., Udumula R.R., Nizami T.K., Ch K.R.R., Padmanaban S.

    Article, International Journal of Circuit Theory and Applications, 2023, DOI Link

    View abstract ⏷

    Lighting systems using light-emitting diode (LED) have drawn significant attention across the world. This is due to their promising features such as high energy efficiency, reduced greenhouse gas emission, and eco-friendly nature. However, these systems require constant current regulators to provide constant illumination. This article proposes a soft-switched full-bridge LED driver circuit for dc-grid applications with dimming control operation. The circuit consists of a soft-switched full-bridge converter to power different LED lamps with reduced device count from dc-grid voltage. The semiconductor switches of the full-bridge converter conduct a small current during on time due to interleaved inductor and equal current sharing of lamp-2 and lamp-3. This feature reduces the conduction losses. In addition, the proposed converter yields less component count per lamp, dimming operation through on–off control and zero voltage switching, which results in low switching losses. The detailed steady-state analysis of the proposed converter for dc-grid applications with dimming control operation is presented in this work. The performance of the proposed converter is compared with other similar topologies available in the recent literature. Numerical simulations and real-time experimental validations are conducted to evaluate the steady-state performance of the proposed converter topology for LED applications, driving multiple lamp loads from dc-grid. It has been established that the efficiency of the proposed full-bridge converter is 97.52% at the rated power.
  • Development of enhanced direct torque control for surface-mounted permanent magnet synchronous motor drive operation

    Meesala R.E.K., Udumula R.R., Nizami T.K., Hosseinpour A.

    Article, IET Power Electronics, 2023, DOI Link

    View abstract ⏷

    Direct torque control (DTC) is one of the most prominent control techniques used by permanent magnet synchronous motor (PMSM) drives in industry applications. Nevertheless, the presence of hysteresis controllers and inaccurate voltage switching table in traditional DTC results in higher torque and flux ripple. This study proposes an enhanced DTC functioned Surface-mounted PMSM (S-PMSM) drive with mitigation of torque and flux ripple. The operation relies on generating the reference voltage vector (VV) in a stationary reference frame, which supports control of torque and flux without hysteresis controllers. The reference VV generation is simple and does not affect control robustness. The position of reference VV in a sector is used to build the voltage vector (VV) switching table. As a result, the application of nearest discrete VV to reference VV produces optimal torque and flux control. Moreover, redundant switching combinations of null VV are effectively used for possible minimization of switching frequency of two-level voltage source inverter (VSI) supplied S-PMSM drive. Therefore, proposed DTC gains improved S-PMSM drive response along with switching frequency reduction. In dSPACE-RTI 1104 platform, experimental response of S-PMSM drive under various operating conditions have been depicted to highlight the proficiency of proposed DTC in comparison with existing DTC.
  • An Efficient Soft-Switched LED Driver for Street Lighting Applications with Input Regulation

    Patakamoori A., Udumula R.R., Nizami T.K., Ch K.R.R.

    Article, IEEE Journal of Emerging and Selected Topics in Power Electronics, 2023, DOI Link

    View abstract ⏷

    In this article, an efficient soft-switched light emitting diode (LED) driver with input regulation is proposed. The converter drives multiple lamps, and it is divided into two sections. Lamp-2 and lamp-3 are driven by a full bridge converter (FBC), while lamp-1 is placed in series with the input dc voltage source. Power is delivered to lamp-1 without passing through the FBC, which results in improved efficiency. The main benefits of the presented LED driver are: 1) lower current ratings of the FBC switches; 2) ripple-free lamp currents; 3) zero voltage switching (ZVS); 4) high power efficiency; 5) drives multiple lamps; 6) input regulation for source variation; and 7) lower components per lamp. To reduce the current rating of FBC switches, two identical lamps are powered using interleaved inductors. Owing to this, the lamps experience ripple-free currents. Further, due to this, the ZVS is achieved which results in high efficiency. A closed-loop buck-boost converter will compensate for the variations in input by adjusting the duty cycle. The converter operating modes, steady state, and efficiency analysis are discussed in detail. Moreover, to indicate the performance of the converter, a 130 W prototype is built, and experimental results are presented.
  • Comparative Study of Various DC-DC Converter Topologies for PV Powered EV Charging Stations

    Vijayan M., Ramanjaneya Reddy U., Mahto T.

    Conference paper, ECS Transactions, 2022, DOI Link

    View abstract ⏷

    There is a drift in the automotive industry from conventional internal combustion engines (ICE) to Electric Vehicles (EV's). This drift from ICE to EV's counts to the reduced carbon emission and thus reducing the environmental pollution. EV's also finds a solution for increasing fossil fuel costs. When it comes to renewable energy sources, typically solar energy it is affluent and reliable. The usefulness of solar energy is maximized by the incorporation of advanced power converter topologies along with their advanced controls. This paper aims to compare some of the boost converter topologies that are used in EV applications with solar photo voltaic-powered charging stations. The comparative study is conducted on various parameters such as DC voltage gain, duty cycle, efficiency, voltage stress, merits, and demerits. Simulation results are analyzed and compared using the MATLAB/Simulink platform.
  • Optimal PI-Controller-Based Hybrid Energy Storage System in DC Microgrid

    Vijayan M., Udumula R.R., Mahto T., Lokeshgupta B., Goud B.S., Kalyan C.N.S., Balachandran P.K., C D., Padmanaban S., Twala B.

    Article, Sustainability (Switzerland), 2022, DOI Link

    View abstract ⏷

    Power availability from renewable energy sources (RES) is unpredictable, and must be managed effectively for better utilization. The role that a hybrid energy storage system (HESS) plays is vital in this context. Renewable energy sources along with hybrid energy storage systems can provide better power management in a DC microgrid environment. In this paper, the optimal PI-controller-based hybrid energy storage system for a DC microgrid is proposed for the effective utilization of renewable power. In this model, the proposed optimal PI controller is developed using the particle swarm optimization (PSO) approach. A 72 W DC microgrid system is considered in order to validate the effectiveness of the proposed optimal PI controller. The proposed model is implemented using the MATLAB/SIMULINK platform. To show the effectiveness of the proposed model, the results are validated with a conventional PI-controller-based hybrid energy storage system.
  • Legendre Neural Network based Intelligent Control of DC-DC Step Down Converter-PMDC Motor Combination

    Nizami T.K., Gangula S.D., Reddy R., Dhiman H.S.

    Conference paper, IFAC-PapersOnLine, 2022, DOI Link

    View abstract ⏷

    Angular velocity control in DC-DC converter-driven direct current (DC) motors exhibit several challenges in numerous applications. This article proposes a novel single functional layer Legendre neural network integrated adaptive backstepping control technique for the DC-DC step down converter-permanent magnet DC (PMDC) motor system. The proposed controller first aims to estimate the uncertainties in an online mode and then compensate the same efficiently during the robust control action. The closed loop feedback stability of the entire system under the action of proposed controller and the online adaptive learning laws are proved using Lyapunov stability criterion. Further, the proposed controller is numerically simulated for various test conditions including; (a) startup response, (b) a step change in the load torque and (c) reference angular velocity tracking. The transient performance measures of angular velocity such as peak overshoot, peak undershoot and settling time have been observed under the proposed control design and compared with the response obtained from proportional-integral-derivative (PID) controller. Finally, the results presented demonstrate the efficacy of the proposed controller in yielding an enhanced performance under both nominal and perturbed test conditions over a wide operating range.
  • High Gain Boost Converter Fed Single-Phase Sine Pulse Width Modulated Inverter

    Kotana R., Bindu S.K.H., Udumula R.R., Goud B.S.

    Article, International Journal of Renewable Energy Research, 2022, DOI Link

    View abstract ⏷

    A high gain boost converter fed single-phase voltage source inverter with its control for DC to AC power conversion in uninterrupted power supply and renewable energy applications is presented in this paper. The conventional DC-DC boost converter with a coupled inductor and switched capacitor is utilized to obtain high gain. Further, the output voltage of the inverter is controlled by sinusoidal pulse width modulation technique. The detailed design and analysis of high gain boost converter fed single-phase voltage source inverter is also presented. The sine pulse width modulation control scheme for the voltage source inverter is developed and presented. In order to validate the high gain boost converter fed single-phase voltage source inverter, the simulation model is developed in LTspice software environment and results are validated. The results show high gain boost converter achieves a gain of about 10 and the single-phase voltage source inverter is able to provide a rms voltage of 228 V without using the step-up transformer. The total harmonic distortion of output current is found to be reduced below 4%. Further, the results obtained are found to be in close agreement with theoretical values.
  • Seagull Optimization Algorithm–Based Fractional-Order Fuzzy Controller for LFC of Multi-Area Diverse Source System With Realistic Constraints

    Naga Sai Kalyan C.H., Goud B.S., Reddy C.R., Udumula R.R., Bajaj M., Sharma N.K., Elgamli E., Shouran M., Kamel S.

    Article, Frontiers in Energy Research, 2022, DOI Link

    View abstract ⏷

    This study initiates the implementation of fractional-order (FO) fuzzy (F) PID (FOFPID) controller fine-tuned using a seagull optimization algorithm (SOA) for the study of load frequency control (LFC). Initially, the SOA-tuned FOFPID regulator is implemented on the widely utilized model of dual-area reheat-thermal system (DARTS), named test system-1 in this work for a perturbation of 10% step load (10% SLP) on area-1. Dynamical analysis of the DARTS system reveals the viability of the SOA-tuned FOFPID control scheme in regulating frequency deviations effectively compared to other control schemes covered in the literature. Later, the presented regulator is implemented on the multi-area diverse sources (MADS) system possessing realistic constraints in this study, termed test system-2. The sovereignty of the presented FOFPID controller is once again evidenced with controllers of PID/FOPID/FPID fine-tuned with the SOA approach. Moreover, the effect of considering practical realistic nonlinearity constraints such as communication time delays (CTDs) on MADS system performance is visualized and the necessity of its consideration is demonstrated. Furthermore, AC-DC lines are incorporated with the MADS system to enhance the performance under heavy-load disturbances and the robustness of the proposed regulatory mechanism is deliberated.
  • PV/WT Integrated System Using the Gray Wolf Optimization Technique for Power Quality Improvement

    Goud B.S., Rami Reddy C., Naga Sai kalyan C., Udumula R.R., Bajaj M., Abdul Samad B., Shouran M., Kamel S.

    Article, Frontiers in Energy Research, 2022, DOI Link

    View abstract ⏷

    This paper presents the integration of renewable energy sources such as photovoltaics, wind, and batteries to the grid. The hybrid shunt active power filter (HSHAPF) is optimized with the Gray wolf optimization (GWO) and fractional order proportional integral controller (FOPI) for harmonic reduction under nonlinear and unbalanced load conditions. With the use of GWO, the parameters of FOPI are tuned, which effectively minimizes the harmonics. The proposed model has effectively compensated the total harmonic distortions when compared with without the filter and with the passive filter, the active power filter with a PI controller, and the GWO-FOPI-based controller. The performance of the proposed controller is tested under nonlinear and unbalanced conditions. The parameters of the FOPI controller are better tuned with the GWO technique. The comparative results reflect the best results of GWO-FOPI-based HSHAPF. The suggested controller is built in the MATLAB/Simulink Platform.
  • Selection of Reference Flux Linkage for Direct Torque Control Based Induction Motor Drive in Electric Vehicle Applications

    Singh A.K., Reddy U., Prabhakar K.K., Kumar P.

    Article, SAE International Journal of Alternative Powertrains, 2019, DOI Link

    View abstract ⏷

    The surge in economic activities, in the developing nations, has resulted in rapid expansion of urban centres. This expansion of cities has caused a rapid increase in vehicular traffic, which in turn has caused deterioration of air quality. To overcome the problem of unprecedented air pollution, the governments worldwide have framed policies for faster adoption of electric vehicles. One of the major challenges faced is the development of low-cost drive for these vehicles and keeping the imports to a minimum. As a result of this, the trend is to move away from the permanent magnet-based motor technology and to use induction motor-based drivetrain. For the induction motors to be successful in electric vehicle drivetrain application, it is important to have a robust speed control algorithm. This work aims at adapting a direct torque control technique for induction motor's speed control. The work addresses the impact of reference flux linkage on the operation of an induction motor for direct torque control over a wide range of operation. A Finite Element Analysis based induction motor model is used to obtain values of reference flux linkage. The method uses offline calculations to determine the reference flux linkage, and a lookup table is generated using these flux linkage values. This lookup table is eventually implemented with the direct torque control algorithm. The proposed methodology for selecting reference flux linkage is compared with variable flux technique for various vehicle driving cycles. The comparison shows that the proposed approach gives satisfactory performance (in terms of speed response, torque and flux linkage) over a wide operating speed range. Furthermore, energy consumption analysis for considered driving cycles is also discussed.
  • High step-down dual output light emitting diode driver

    Ramanjaneya Reddy U., Narasimharaju B.L., Koreboina V.B.

    Article, International Journal of Renewable Energy Research, 2017,

    View abstract ⏷

    A conventional power factor correction (PFC) based light emitting diode (LED) drivers composed of two-stage DCDC conversions has several drawbacks such as; increased system size due to more component count, less efficiency and complex control etc. The grid powered LED lighting demand for high step-down conversion because the required voltage level of LED light is very less. Thus, this work proposes a one-switch dual-output (OSDO) coupled-inductor buck (CIB) LED driver. The OSDO-CIB converter can eliminates the drawbacks of conventional counterparts. The proposed OSDO-CIB converter can provide various benefits such as; compact size, high efficiency, less total harmonic distortion (THD), simple control, and a significant reduction in device voltage/current rating due to coupled inductors. The converter is designed with discontinuous conduction mode (DCM) of operation in order to achieve in-phase current and voltage, high power factor (PF) and a low THD. This paper mainly emphasized on detailed operating modes and steady-state analysis of proposed converter. Further, prototype of the converter is built and experimental validations are presented.
  • Single-stage electrolytic capacitor less non-inverting buck-boost PFC based AC-DC ripple free LED driver

    Reddy U.R., Narasimharaju B.L.

    Article, IET Power Electronics, 2017, DOI Link

    View abstract ⏷

    This study proposes electrolytic capacitor (EC) less power factor correction (PFC) light emitting diode (LED) driver with reduced current ripple. Generally PFC LED drivers need massive ECs to diminish output current ripple. The life-span of LED driver significantly reduces due to short life-span of ECs, and hence demands for EC-less LED drivers. The proposed LED driver is composed of non-inverting buck-boost PFC converter and bi-directional converter (BDC) for ripple current cancellation which replace the short-life ECs with long-life film capacitors. The PFC converter is designed with discontinuous conduction mode in order to ensure unity power factor operation. The role of BDC is to absorb second harmonic ac ripple current of PFC converter and allow the dc current to LED load. In addition, the desired BDC output voltage (vcbc) is higher than the PFC output voltage (VLED) irrespective of ac source voltage, hence, simplifies the control complexity. Theoretical analysis and predictions of the system have been validated using MATLAB/Simulink simulation, and experimentally validated with a prototype of 7 W. The results evident that PFC integrated BDC provide reduced ripple current with film capacitor as compared with EC counterpart and hence increase the life-span of LED driver.
  • A Cost-Effective Zero-Voltage Switching Dual-Output LED Driver

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Article, IEEE Transactions on Power Electronics, 2017, DOI Link

    View abstract ⏷

    Coupled-inductor (CI) converters are widely used in the light-emitting diode (LED) lighting applications due to several advantages, such as high step-down conversion, reduced switch/diode stress as compared to conventional buck converters. However, the main drawback of CI buck converter is high-voltage spikes during turn-OFF instant due to the leakage inductance of a CI, which leads to switching device failure. Passive clamp circuits are used to overcome the leakage inductance problem, but these clamp circuit's results in reduced efficiency and increased cost. This paper proposes a high step-down zero-voltage switching dual-output coupled-inductor buck (ZVS-DOCIB) LED driver with dimming control. The proposed LED driver provides various advantages like high step-down conversion, effective recovery of leakage energy, elimination of voltage spikes, reduced switching loss due to ZVS operation of both the switching devices, and less switching device count, particularly for multioutput drivers. Also, ZVS operation provides a significant reduction in switching losses, which results in high efficiency. Furthermore, dimming control is studied to regulate the average output currents. This paper presents design and analysis of the proposed ZVS-DOCIB converter. A prototype of the converter has developed and validated experimentally with simulation counterparts.
  • Modeling and analysis of voltage controlled positive output synchronous buck-boost converter

    Narasimharaju B.L., Bharma G., Koreboina V.B., Reddy U.R.

    Conference paper, 12th IEEE International Conference Electronics, Energy, Environment, Communication, Computer, Control: (E3-C3), INDICON 2015, 2016, DOI Link

    View abstract ⏷

    Now a day's use of portable devices increasing more. Such as cellular phones, digital cameras and high efficient power managing modules etc. are demanding for low output voltage ripple with fast transient response. The terminal voltage of the battery used in portable applications varies particularly depending on state of their charging conditions. In this paper, Li-ion battery is considered that provides 4.2V when it is fully charged and drops to 2.7V when fully discharged. However, the system requires a constant output voltage of 3.3V under varying load conditions. Thus, this work addresses the design and modeling of voltage controlled positive output synchronous buck-boost converter. Simulation model is developed using MATLAB/Simulink and results analysis has been carried out.
  • Improved efficiency coupled inductor-buck AC-DC light emitting diode (LED) driver

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Article, IEICE Electronics Express, 2016, DOI Link

    View abstract ⏷

    This work proposes coupled inductor-buck (CI-B) power factor correction (PFC) LED driver. As compared with conventional buck converters, the proposed CI-B PFC converter has several advantages such as; high step-down conversion, reduced total harmonic distortion (THD), increased efficiency, achieves high power factor (PF), reduced current/voltage stress of switch/diode, and effective switch utilization factor. The proposed converter is designed to operate in discontinuous current mode (DCM) to achieve high power factor (PF) and low THD to comply IEC 61000-3-2 class C standards. In addition, a simple one-loop voltage mode controller (VMC) is implemented to achieve the desired regulated output voltage. A proto-type of 16 Watt converter is built and experimental validations are presented.
  • Unity power factor buck-boost LED driver for wide range of input voltage application

    Reddy U.R., Narasimharaju B.L.

    Conference paper, 12th IEEE International Conference Electronics, Energy, Environment, Communication, Computer, Control: (E3-C3), INDICON 2015, 2016, DOI Link

    View abstract ⏷

    LED lighting sources have been used in several applications than established lighting sources due to their high luminous efficiency, environmental friendly, long life, compact size, and not affected by cold temperature. This paper deals with the design of buck-boost LED driver for wide input voltage applications. The proposed LED driver is a combination of uncontrolled rectifier followed by buck-boost converter. This converter is appropriate for wide input voltage applications from 85 Vac - 265 Vac. Over the line range, this topology accomplishes less total harmonic distortion (THD) and good power factor (PF). Average current control scheme is worn to accomplish improved power factor (PF) with low harmonics of line current. Simulation of buck-boost converter with LED load has been developed using PSIM software for 33.67 W. Load has modelled by connecting 13 LEDs in series by supplying 3.7 V & 0.7 A for each LED. For the proposed LED driver, parameter like power factor (PF) and total harmonic distortion (THD) of source current are assessed, it shows the power factor and THD of source current is very low and satisfies the IEC-61000-3-2 class C limits.
  • Enhanced closed loop voltage control of buck converter for improved performance

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Conference paper, 11th IEEE India Conference: Emerging Trends and Innovation in Technology, INDICON 2014, 2015, DOI Link

    View abstract ⏷

    In this paper, author proposes study of two-loop voltage mode controlled (TVMC) buck converter for improved transient and dynamic performance under line and load disturbances. Buck converter with voltage mode control will improve efficiency, but transient response is sluggish. It requires large filter capacitor. Two-loop voltage control technique is proposed to improve output voltage regulation irrespective of line and load disturbances, and to achieve fast transient response. The two-loop voltage control technique has many advantages over conventional voltage mode control technique, such as fast transient response and reduced peak overshoot etc. Simulation model of TVMC buck converter is developed in MATLAB/Simulink and extensive result analysis has been made. The result analysis shows the effectiveness and significant improvement of the proposed control technique.
  • Optimized dual active bridge Bi-directional DC-DC converter for UPS application

    Narasimharaju B.L., Prahlad V.V., Reddy U.R., Vijay Babu K., Srinivasan P.

    Conference paper, 2014 IEEE International Conference on Power Electronics, Drives and Energy Systems, PEDES 2014, 2014, DOI Link

    View abstract ⏷

    With the growing emphasis on smaller compact and efficient power system there is increasing interest in the possibility of using Bi-directional converters especially in DC based power applications. Having the capability of bilateral power flow, that provides the functionality of two uni-directional converters in single converter unit; Bidirectional converters have the increased industrial applications; demand optimized study of topologies and feasibility, critical feature study for the considered application. This document suggests an optimized implementation of Bidirectional DC-DC converter to fit the present day UPS application. Key issues like compact design, utilisation of transformer core, optimised topology for low power (2.5kW) applications were discussed.

Patents

  • A soft-switched led driver system

    Dr Ramanjaneya Reddy U, Dr Tousif Khan N

    Patent Application No: 202341088805, Date Filed: 04/02/2026, Date Published: 26/12/2023,

  • Zero voltage switching full-bridge converter for multiple led lighting loads with reduced switch current

    Dr Tousif Khan N, Dr Ramanjaneya Reddy U

    Patent Application No: 202241076718, Date Filed: 29/12/2022, Date Published: 06/01/2003, Status: Granted

  • A multi-port non-isolated bidirectional converter (nmpbc) for dc microgrid applications

    Dr Tarkeshwar Mahto, Dr Ramanjaneya Reddy U

    Patent Application No: 202341052432, Date Filed: 04/08/2023, Date Published: 01/09/2023, Status: Granted

  • A power factor correction buck-boost converter for on-board Electrical Vehicles(EV)

    Dr Ramanjaneya Reddy U

    Patent Application No: 202441075291, Date Filed: 04/10/2024, Date Published: 20/12/2024, Status: Published

  • A bidirectional switched-capacitor dc-dc converter for an  electric vehicle and a method thereof

    Dr Tarkeshwar Mahto, Dr Ramanjaneya Reddy U, Dr Somesh Vinayak Tewari

    Patent Application No: 202441100999, Date Filed: 19/12/2024, Date Published: 03/01/2025, Status: Published

  • A dc to ac conversion apparatus

    Dr Ramanjaneya Reddy U

    Patent Application No: 202241060455, Date Filed: 21/10/2022, Date Published: 04/11/2022, Status: Granted

  • A bi-directional ky converter for an electric vehicle

    Dr Ramanjaneya Reddy U

    Patent Application No: 202341046312, Date Filed: 10/07/2023, Date Published: 01/09/2023, Status: Published

  • A system and a method for adaptive output voltage regulation of dc-dc buck converter

    Dr Tousif Khan N, Dr Ramanjaneya Reddy U, Dr Arghya Chakravarty

    Patent Application No: 202341067955, Date Filed: 10/10/2023, Date Published: 20/10/2023, Status: Published

  • An apparatus for controlling an output of a dc-dc buck converter

    Dr Ramanjaneya Reddy U, Dr Tousif Khan N, Dr Arghya Chakravarty, Dr Priyanka

    Patent Application No: 202441000337, Date Filed: 03/01/2024, Date Published: 02/02/2024, Status: Published

  • Bidirectional ac-dc converter system and a method thereof

    Dr Ramanjaneya Reddy U

    Patent Application No: 202441072548, Date Filed: 25/09/2024, Date Published: 20/12/2024, Status: Published

  • An adaptive control system for regulating speed of a permanent magnet direct current (pmdc) motor

    Dr Tousif Khan N, Dr Ramanjaneya Reddy U, Dr Arghya Chakravarty

    Patent Application No: 202441078254, Date Filed: 15/10/2024, Date Published: 25/10/2024, Status: Published

  • An asymmetrical voltage resonant converter system

    Dr Ramanjaneya Reddy U

    Patent Application No: 202441080740, Date Filed: 23/10/2024, Date Published: 03/01/2025, Status: Published

  • A control system and method for regulating the output speed of a dc motor driven by a dc-dc buck power converter

    Dr Tousif Khan N, Dr Ramanjaneya Reddy U, Dr Arghya Chakravarty

    Patent Application No: 202541000092, Date Filed: 01/01/2025, Date Published: 10/01/2025, Status: Published

  • System and method for maximum power point tracking in solar photovoltaic systems under shaded conditions

    Dr Tousif Khan N, Dr Ramanjaneya Reddy U

    Patent Application No: 202541009166, Date Filed: 04/02/2025, Date Published: 14/02/2025, Status: Published

  • System and method for maximum power point tracking (mppt) in solar photovoltaic (pv) systems under shaded conditions

    Dr Tousif Khan N, Dr Ramanjaneya Reddy U

    Patent Application No: 202541010369, Date Filed: 07/02/2025, Date Published: 21/02/2025, Status: Published

Projects

Scholars

Doctoral Scholars

  • Challa Siva Koti Reddy
  • Ms Dasari Sai Ram Surya Lakshmi Avanthika
  • Mr Kamireddy Ravivarma
  • Ms Maya Vijayan

Interests

  • Control Systems
  • High Gain Converters
  • Power Electronics

Thought Leaderships

There are no Thought Leaderships associated with this faculty.

Top Achievements

Research Area

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Recent Updates

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Education
2009
B.Tech
Jawaharlal Nehru Technological University
India
2012
M.E.
Bangalore University,
India
2017
Ph.D.
National Institute of Technology
India
Experience
  • Nov 2020 - Till date | Assistant Professor | Department of Electrical and Electronics Engineering | SRM University-AP, Andhra Pradesh, India.
  • Apr 2017 – Nov 2020 | Associate Professor | Department of Electrical and Electronics Engineering | Vardhaman College of Engineering, Hyderabad, India (Study Leave from Nov 2017 – Sep 2018).
  • Nov 2017 – Sep 2018 | Post-Doctoral Fellow | Microelectronics Laboratory | University of Crete, Greece.
  • Dec 2013 – Apr 2017 | Senior Research Fellow | Department of Electrical Engineering | National Institute of Technology Warangal, India.
  • Dec 2012 – Dec 2013, | Assistant Professor | Department of Electrical and Electronics Engineering | Chiranjeevi Reddy Institute of Engineering and Technology, Andhra Pradesh, India.
Research Interests
  • Power Electronics - Converters, PWM Techniques, Applications to Lighting System.
  • High Gain Converters for Renewable Energy Applications.
  • Development of control algorithms for converter fed drives.
Awards & Fellowships
  • 2022 - Research Scholar worked under my guidance secured Gold medal (Feb-2022) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2022 - Research Scholar worked under my guidance secured Gold medal (Sep-2022) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2021 - Undergraduate students worked under my guidance secured Gold medal (Aug-2021) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2021 - Research Scholar worked under my guidance secured Gold medal (Aug-2021) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2017 – Received funding for Post Doctoral Fellow – European Government
  • 2015 – Best Paper award at IEEE INDICON Conference – IEEE Delhi Section
  • 2013 – MHRD Fellowship for Doctoral Study – Government of India
  • 2010 – MHRD Fellowship for Masters Study – Government of India
Memberships
  • Senior Member - IEEE
  • Member – Institute of Engineers
Publications
  • Dual Estimation of State of Charge and State of Health of a Battery: Leveraging Machine Learning and Deep Neural Networks

    Avanthika D.S.R.S.L., Udumula R.R., Lokeshgupta B., Morampudi M.K.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    Accurate estimation of battery state including state of charge (SoC) and state of health (SoH) are crucial for ensuring safety in energy storage applications. The SOC and SOH estimators were independently trained using the same input vector but with different objective functions, no integration between SOC and SOH estimations were explored. In this paper, a unified algorithm, for identifying both SoC and SoH states, is introduced by considering the Bayesian optimization for hyperparameter tuning. This approach allows seamless transition between SoC and SoH estimation without needing separate models for each task. In addition, equipping the dual estimation framework with a unified algorithm for identifying both states would impact the algorithm's complexity. The suggested BiLSTM model reduces complexity in real-time Battery Management System (BMS) applications by eliminating the need for a separate model to estimate SoH. When compared to other machine learning and deep learning models such as Support Vector Machines (SVM), Decision Trees (DT), Random Forest (RF), Radial Basis Function Neural Networks (RBF-NN), Recurrent Neural Networks (RNN), and LSTM, the suggested BiLSTM method demonstrates the highest efficiency. Finally, to verify the proposed method's effectiveness, a comparison among the different evaluation metrics was conducted. The proposed BiLSTM model achieved an average MAE (Mean Absolute Error) of 0.08 and NRMSE (Normalized Root Mean Squared Error) of 0.15 for SoC estimation across various temperatures (5°C, 15°C, 35°C, and 45°C), and an MAE of 3.12 and NRMSE of 0.23 for SoH estimation with a degradation rate of 47% of the cell estimated from the predicted capacity values.
  • Power Factor Correction(PFC) for EV Charger Using PI Controller in G2V Application

    Adari J.V., Tewari S.V., Chakravarty A., Udumula R.R., Sagar G.J., Mahto T.

    Conference paper, 1st International Conference on Sustainable Energy Technologies and Computational Intelligence: Towards Sustainable Energy Transition, SETCOM 2025, 2025, DOI Link

    View abstract ⏷

    This paper presents an AC-DC converter system tailored for grid-to-vehicle (G2V) applications, aimed at facilitating efficient power flow while achieving a Unity power factor (UPF). The system employs a rectifier for AC-DC conversion, which effectively steps up a 230V AC input to a 380V DC output. This DC output can be further regulated using a buck converter to meet specific load requirements. A Proportional-Integral (PI) controller is implemented to oversee the voltage and current regulation, thereby minimizing harmonic distortion and enhancing the overall power factor. By actively managing the input voltage and current, the controller ensures that the system operates within desired parameters, thus optimizing power quality. Comprehensive simulation results validate the system's performance, demonstrating its capability to maintain a UPF in G2V mode. The findings indicate significant reductions in total harmonic distortion (THD), reinforcing the system's effectiveness in managing power quality. This AC-DC converter design not only enhances the efficiency of power flow in electric vehicle charging systems but also contributes to the stability of the grid by minimizing reactive power and harmonics. Overall, this work represents a significant advancement in converter technology for sustainable transportation and energy management.
  • Nonlinear Adaptive Neural Control of Power Converter-Driven DC Motor System: Design and Experimental Validation

    Nizami T.K., Gangula S.D., Udumula R.R., Chakravarty A., Ahmad F., Hosseinpour A.

    Article, Engineering Reports, 2025, DOI Link

    View abstract ⏷

    This article presents an intelligent adaptive neural control scheme to track the output speed trajectory in power converter-driven DC motor system. The proposed technique integrates an adaptive polynomial-neural network with a backstepping strategy to yield a robust control system for output tracking in DC motor. Such a unification of online neural network-based estimation and adaptive control, results in effective regulation of the output across a wide load torque uncertainties, besides yielding a promising transient and steady-state performance. The stability of the entire closed-loop system is ensured through Lyapunov stability criterion. The efficacy of the proposed strategy is revealed through an extensive experimental investigation under various operating points during start-up, step-reference tracking, and external step-load torque disturbances. The real-time experimentation is conducted on a laboratory prototype of power converter-driven DC motor of 200 W, using dspace DS1104 control board with MPC8240 processor. The results obtained confirm an improvement in the transient response of the output speed by significantly reducing the settling time to (Formula presented.) and yielding a steady state behavior with no peak over/undershoots during load disturbances, in contrast to other similar works presented in the literature intended for same the application.
  • Zernike radial basis neural network control of DC–DC power converter driven permanent magnet DC motor: design and experimental validation

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A., Ahmad F.

    Article, Electrical Engineering, 2025, DOI Link

    View abstract ⏷

    This article presents a novel control architecture for an enhanced closed-loop speed tracking of a DC–DC buck power converter fed Permanent Magnet DC motor (PMDC) motor in face of large exogenous load torque uncertainty. The proposed architecture combines a new self learning Zernike radial polynomial neural network (ZRNN) estimator with the backstepping controller. The design involves a computationally simple online learning based ZRNN to rapidly and accurately estimate the unknown large load torque uncertainties. The proposed control solution concurrently guarantees stability and excellent dynamic performance through an effective neural network based estimation and subsequent compensation of unanticipated load torque perturbations over a wide range. The closed loop stability of the DC–DC buck power converter driven PMDC motor and asymptotic speed tracking with the proposed neuro-adaptive controller is proved using the stability theory for non-autonomous systems. The effectiveness of the proposed controller has been investigated through experimentation on an indigenously developed laboratory prototype of 200 W under closed loop operation using digital signal processors. The tests conducted around different operating conditions include the motor start-up response, step variations in the load torque, and step changes in the reference speed. Experimental results demonstrate a significant improvement in the speed tracking performance achieving 48.13% reduction in the settling time and no-change in speed during start-up and load torque perturbations upto 600%, respectively. Experimental validations and extensive tests spanning over a large operating region, substantiate the theoretical claims and real-time suitability of the proposed controller for sensitive applications demanding high performance.
  • Non-isolated High-Gain DC-DC Converter with Moderate Gain for Hybrid Energy System Applications on DC Microgrids

    Vijayan M., Ramanjaneya Reddy U., Mahto T.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    A novel non-isolated High-Gain DC-DC Converter with Moderate Gain for Hybrid Energy System applications on DC Microgrids. The paper proposes a novel high-gain DC-DC converter for Hybrid energy systems such as Solar Photovoltaic (PV) systems, Fuel cells (FC), etc. The converter can replace the necessity of multiple converters for multiple sources. The major contributions are the lower switch voltage stress, High boost gain, multiple input capability, and lower component count as a dual source capability. The design and analysis of ideal and non-ideal conditions of the components are discussed and the individual effects of each component are analyzed. Further, the non-ideal gain and non-ideal efficiency are derived and presented. Also, Simulation results with a rated power of 100W are presented.
  • A Novel High Gain Tertiary Port Boost Converter for Hybrid Energy System Integration

    Vijayan M., Udumula R.R., Mahto T.

    Article, IEEE Transactions on Consumer Electronics, 2025, DOI Link

    View abstract ⏷

    This paper introduces novel high-gain tertiary port boost converter (HGTPBC) designed for hybrid energy sources such as solar photovoltaic (PV) and fuel cells (FC). The converter is employed with dual input sources by facilitating modular converters and accomplishes a high step-up voltage gain by virtue of a voltage multiplier in a DC microgrid, where the prosumers can have an islanded operation. The proposed topology allows home appliances to be powered by multiple energy source without the need for a large storage unit. Key features include continuous input current, reduced normalized voltage stress on switches, expandability for multiple input sources and independent source control. The independent control facilitates the standalone operation with single source during source failure or absence. To evaluate the converter performance, a thorough steady-state analysis, both with and without consideration of nonidealities is carried out. Detailed comparisons with existing converter topologies highlight the advantages of the proposed converter. Moreover, the loss distribution and efficiency analysis of proposed converter are presented and found to be 91.59% efficiency at rated power. Theoretical aspects are validated through hardware testing on a 100W laboratory prototype.
  • Development of bi-directional switched-capacitor DC-DC converter for EV powertrain application

    Mounika Nagabushanam K., Mahto T., Tewari S.V., Udumula R.R., Alotaibi M.A., Malik H., Ustun T.S.

    Article, Engineering Science and Technology, an International Journal, 2025, DOI Link

    View abstract ⏷

    The research presents a novel Bidirectional Switched Capacitor DC-DC (BSCD) Converter and demonstrates its application in integrating a battery with an electric vehicle's (EV) traction motor. During discharging, the motor is powered by the battery through the converter, and during charging, the traction motor functions as a generator, returning the recovered energy to the battery via the converter. The recommended converter employs a two-duty cycle operation to enhance voltage gain while minimizing circuit components. It utilizes a switched capacitor (SC) cell, enhancing the voltage transfer ratio by operating capacitors CS1 and CS2 in parallel or series. The work includes analysis of the converter's steady state, mathematical approach, state-space modelling, stability, and efficiency. The proposed converter achieves an efficiency of 90.66 % in charging mode and 96.6 % in discharging mode, with a Gain Margin of 54.4 dB and Phase Margin of 8.09°, indicating stability. Comparative evaluations with existing BDCs are also provided. The implementation of a closed-loop simulation using MATLAB/Simulink and dSpace software validates the performance of the suggested converter-based drive. Furthermore, an experimental investigation of a 200 W, 30 V/430 V configuration confirms the converter's practical viability.
  • Zero voltage switching with reduced current stress for LED lighting applications

    Rao K.V.G., Kumar M.K., Goud B.S., Udumula R.R., Reddy C.R., Balachandran P.K., Zainuri M.A.A.M., Ramasamy S.

    Article, IET Power Electronics, 2025, DOI Link

    View abstract ⏷

    Lighting systems using light emitting diode (LED) have drawn significant attention across the world. Nevertheless, to maintain a steady light output, these systems necessitate constant current regulators. This article proposes a buck–boost integrated zero voltage switched full-bridge LED converter with low current stress. It powers two identical lamps and a lamp of power rating twice the identical lamp. A direct current voltage source, arranged in series, transmits a portion of light power without conversion. A regulated low power output is provided using a complete bridge converter. The semiconductor switches off the full-bridge converter carry minimal current. This characteristic lowers conduction losses. The suggested converter facilitates dimming operation via on–off control and zero voltage switching, leading to minimal switching losses. Further input voltage of full-bridge converter is modulated to maintain constant LED lamp current. The detailed steady-state analysis and implementation of the proposed full-bridge LED converter with dimming control operation is presented here.
  • Random Forest based Machine Learning Algorithm for Estimating State of Charge in Lithium-ion Batteries

    Avanthika D.S.R.S.L., Lokeshgupta B., Udumula R.R.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    This paper proposes a Random Forest (RF) machine learning algorithm-based prediction model for the state of charge (SoC) level of lithium-ion batteries for electric vehicles. To show the effectiveness of the proposed prediction model performance, the RF model has been compared with the other machine learning algorithms such as Support Vector Machines (SVM) and Gradient Boosting (GB) approaches. The dataset includes cell temperature, state of charge (SoC), voltage, and current readings at three different external temperatures-15, 25, and 30 degrees Celsius are considered in this paper to test the performances of the proposed model. After preprocessing of the dataset, 20% of the data was used for testing and the remaining 80% for training purposes. The various metrics such as mean squared error (MSE), mean absolute error (MAE), coefficient of determination (R2), root mean squared error (RMSE), normalized root mean squared error (NRMSE), residual standard error (RSE), and relative absolute error (RAE) are usually preferred to evaluate the performance of the prediction models. The simulation results of the proposed model clearly show the effectiveness of SoC-level estimation for real-time battery management systems (BMS) when compared to other machine learning algorithms. The efficiency of the proposed model is 99% and execution time is less than 5 seconds. The accurate estimation of the SOC of lithium-ion batteries is crucial for optimizing battery performance, ensuring safety, and extending battery life in electric vehicles.
  • Real Time Implementation of Buck Converter Using Optimized Type Compensators

    Gangula S.D., Mukhtar A., Nizami T.K., Chakravarty A., Udumula R.R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This work investigates the application of Artificial Bee Colony (ABC) optimization for the design of Type compensators utilizing the dual-loop control scheme. The proposed Type compensators integrate the ABC optimization for regulating the closed-loop operation of a DC-DC buck converter. Such an integration of ABC optimization, aids in effectively regulating the output voltage and inductor current, besides ensuring enhanced time domain criteria. The proposed dual-loop control scheme consists of a current loop and a voltage loop. The current loop regulates the inductor current and the voltage loop regulates the output voltage. The efficacy of the proposed method is revealed through extensive simulation and experimental investigation under start-up response, step perturbations in external load. The experimentation is conducted on a laboratory prototype using dspace DS1104 control board.
  • Self-learning Controller Design for DC–DC Power Converters with Enhanced Dynamic Performance

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A.

    Article, Journal of Control, Automation and Electrical Systems, 2024, DOI Link

    View abstract ⏷

    This article presents a promising self-learning-based robust control for output voltage tracking in DC–DC buck power converters, particularly for applications demanding high precision performance in face of large load uncertainties. The design involves a computationally simple online single hidden layer neural network, to rapidly estimate the unanticipated load changes and exogenous disturbances over a wide range. The controller is designed within a backstepping framework and utilizes the learnt uncertainty from the neural network for subsequent compensation, to eventually ensure an asymptotic stability of the tracking error dynamics. The results obtained feature a significant improvement of dynamic and steady-state performance concurrently for both output voltage and inductor current in contrast to other competent control strategies lately proposed in the literature for similar applications. Extensive numerical simulations and experimentation on a developed laboratory prototype are carried out to justify the practical applicability and feasibility of the proposed controller. Experimental results substantiate the claims of fast dynamic performance in terms of 94% reduction in the settling time, besides an accurate steady-state tracking for both output voltage and inductor current. Moreover, the close resemblance between computational and experimental results is noteworthy and unveils the immense potential of the proposed control system for technology transfer.
  • Power Factor Correction Buck-Boost Converter for On-Board EV Charging Application

    Udumula R.R., Patnaik S., Nandigama S.K., Dega U.S., Lokeshgupta B., Vemula N.K., Kirankumar N.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    This work presents the power factor correction (PFC) buck-boost converter for on-board electric vehicle (EV) charging applications. The PFC buck-boost converter is designed to operate in discontinuous current conduction mode (DCCM), thus achieving natural PFC for the universal input voltage range. In addition, DCCM operation does not require input voltage or current sensors; as a result, the control is more reliable and economical than continuous current conduction mode (CCCM). Furthermore, the buck-boost converter switch operates in zero current switching (ZCS) which results in reduced switching losses and improves the efficiency. The detailed steady-state analysis, operating modes, and design analysis for DCCM operation are presented. To validate the theoretical studies, a closed-loop voltage mode control of the PFC buck-boost converter is developed and tested in a PSIM software environment. The simulation results uphold the converter analysis and achieve a high power factor and low total harmonic distortion (THD) for the universal input range.
  • A Novel PWM Inverter Powered by Single DC Source for a Multiple Pole Pair Induction Motor

    Nallamekala K.K., Reddy U.R., Mishra P., Vemula N.K., Krishna A.R.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    In this paper, a customized multi-level inverter configuration designed for driving an induction motor with multiple pole pairs is introduced. Within the induction motor, each pole pair winding coil spaced 360° (electrically) apart maintains the same voltage profile. In our case, two windings in a four-pole induction motor are deliberately disconnected. A dual two-level inverter is used to power each half of the winding, so two such inverters are used to feed the entire stator winding of the induction motor as pole pair windings are disconnected. The single DC source used to power these inverters has a magnitude of Vdc/4, or 25% of input voltage DC bus voltage needed to power a typical Neutral Point Clamped five-level inverter. This new Pulse Width Modulation approach is used to cancel the harmonics at first center band while controlling the inverter output voltage. This method successfully lowers torque ripple by reducing current ripple. Furthermore, power balancing problems are eliminated because the single DC source is supplying the entire topology. The capacitor voltage balancing problems are also resolved because this design is derived using only two-level inverters. Very few changes to the design are needed for the suggested topology; the main change is to disconnect winding coils with the same voltage profile. The efficacy of the proposed inverter employing the innovative PWM technique in the linear modulation region is demonstrated by simulation results utilizing a 5-hp four-pole induction motor in MATLAB (Simulink).
  • Independently Controllable Single-Input Dual-Output DC-DC Converter for DC Microgrid Based PV Fed EV Charging Stations

    Vijayan M., Ramanjaneya Reddy U., Mahto T., Narasimharaju B.L., Dogga R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    A new non-isolated single-input dual-output (NI-SIDO) DC-DC converter is proposed in this paper. The converter has the advantage of incorporating multiple outputs for energy storage applications, applicable in DC micro-grid storage systems, Electric vehicular charging stations, battery converters, and renewable energy systems without a filter capacitor. The significant advantage of the converter is it uses the interleaving technique to incorporate the outputs. The voltage stress across the switches and capacitor voltage stress is also reduced drastically. Thus it reduces the capacitor size when compared with the conventional boost converter. A closed-loop control strategy is implemented to control the load voltage as well as the inductor current. The converter is designed, analyzed, implemented, and tested using MATLAB SIMULINK software for 150W. The Simulation results are presented under various operating conditions such as changes in load with solar PV systems. The results from real-time testing are presented with the OPAL-RT system.
  • Control Implementation of BKY Converter for EV Applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Ramanjaneya Reddy U.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This paper proposes BKY converter, which is made to run in continuous conduction mode during both the charging and discharging cycles for low power EV applications. An analysis is conducted on the converter's dynamic behavior, and an approach to control is put forth to manage the power transfer between the traction system and battery in an electric vehicle. The suggested converter is designed using an extracted small-signal model. A significant ripple in the detected current causes switching instability in the current-mode control approaches at low duty ratios. A computation delay occurs when the controller is implemented in the microcontroller. The control algorithm's design takes this into account. A theoretical framework for current and voltage loop gain transfer functions are created using the realistic parameters of a BKY converter. Further, dynamic performance under load variations is explained and validated by simulations.
  • Dynamic Operation of Islanded DC Microgrid with Fuel Cell Using Hybrid Energy Storage Systems

    Vijayan M., Udumula R.R., Mahto T., Bhamidi L.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    Effective utilization of renewable energy sources (RES) is with the better management of their fluctuation nature. Employing hybrid energy storage systems (HESS) in line with the RES will improve the power flow equilibrium in the DC microgrids (DC-MG). In this paper, a PI control-based hybrid energy storage system with a Proton exchange membrane (PEM) fuel cell (FC), battery, and a supercapacitor (SC) for increasing the effectiveness of renewable power in the DC-MG is presented. A validation test is conducted for a 100 W DC microgrid system to verify the effectiveness of the proposed model. The MATLAB/SIMULINK software is used to implement the proposed system.
  • Modified Switched Capacitor-Based Non-isolated Bidirectional DC–DC Converter for Obtaining High VTR

    Nagabushanam K.M., Tewari S.V., Udumula R.R., Mahto T.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    Energy storage systems with a high voltage transfer ratio (VTR) play an important role in integrating modern electric power systems with large-scale renewable energy integration. This article suggests a modified Switched Capacitor non-isolated Bidirectional DC–DC Converter (SCBDC) topology to achieve a high VTR. The presented converter has a simple circuit, simple control, a switched capacitor structure that increases the voltage-gain range, and low-voltage stress on switches, making it suitable for renewable and hybrid energy source electric vehicle applications. Continuous conduction mode is used for the operation principles, steady-state analysis, and extraction of voltage and current equations. Simulation results for the proposed converter were obtained in a MATLAB environment, demonstrating the converter's feasibility.
  • Development of high-gain switched-capacitor based bi-directional converter for electric vehicle applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Udumula R.R., Alotaibi M.A., Malik H., Marquez F.P.G.

    Article, Journal of Energy Storage, 2024, DOI Link

    View abstract ⏷

    High efficiency, high voltage transfer ratio (VTR), and low input ripple current is required in any bidirectional DC-DC converter (BDC) that plays a major role in interfacing batteries in applications like dc microgrids and electric vehicles (EVs). For meeting these requirements, a switched capacitor-based BDC is proposed to interface the battery with a propulsion system via DC Link. It has a simple circuit with only a set of switching operations, High VTR, and lesser ripple current on the low voltage (LV) side are advantages of the proposed High Gain Switched-Capacitor Bi-directional DC-DC Converter (SC-BDC) making it appropriate for use in EVs. The steady-state analysis, design consideration of passive components, loss and efficiency analysis are presented. Finally, the proposed High Gain SC-BDC is compared with few of the existing BDC in the literature. The feasibility of the converter was demonstrated by simulating a 200 W converter and validating results produced in a MATLAB environment.
  • A novel multi-port high-gain bidirectional DC–DC converter for energy storage system integration with DC microgrids

    Vijayan M., Udumula R.R., Mahto T., K.M. R.E.

    Article, Journal of Energy Storage, 2024, DOI Link

    View abstract ⏷

    Bidirectional converters have often been used in numerous applications like DC microgrids, renewable energy, hybrid energy storage systems, electric vehicles, etc. The paper proposes a novel multi-port high-gain (NMPHG) bidirectional DC–DC converter that supports DC microgrid (DC-MG) applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, multiple input ports, lower switch voltage stress, and lower component count owing to the single converter with multiple input ports for DC microgrid applications. The detailed operational principle, analysis, and design considerations of proposed NMPHG bidirectional DC–DC converters are discussed. Furthermore, the loss analysis, detailed comparison with similar works, and efficiency analysis with non-modalities during forward power flow (LV to HV) and reverse power flow (HV to LV) modes are presented. The efficiency of the proposed converter is found to be 93.8% in forward power flow and 92.9% in reverse power flow modes at rated power. Finally, a hardware prototype of the proposed NMPHG bidirectional DC–DC converters is implemented with 100 W in FPF mode and 200 W in RPF mode with a TMS320F28335 processor and validated with theoretical counterparts.
  • A comparative analysis of non-isolated Bi-directional converters for energy storage applications

    Nagabushanam K.M., Tewari S.V., Udumula R.R., Mahto T.

    Review, Engineering Research Express, 2024, DOI Link

    View abstract ⏷

    Bi-directional DC-DC converters (BDC) are required for power flow regulation between storage devices and DC buses in renewable energy based distributed generation systems. The fundamental requirements of the BDC are simple structure, reduced switching components, a wide range of voltage gain, low voltage stress, high efficiency, and reduced size. There are different BDC topologies for various applications based on their requirements in the literature. Various BDC are categorized according to their impedance networks. Isolated BDC converters are large due to high-frequency transformers and hence used for static energy storage applications whereas non-isolated BDC is lightweight and suitable for dynamic applications like electric vehicles. This paper reviews types of non-isolated BDC topologies. The performance of five non-isolated BDC converters under steady state condition is evaluated by using theoretical analysis. On this basis, suitability of BDC for different applications is discussed. Further advantages and limitations of converters are discussed by using comparative analysis. The optimization of BDC for distributed generation systems from the perspectives of wide voltage gain, low electromagnetic interference, low cost with higher efficiency is identified. Theoretical analysis of the converters is validated by simulating 200W converters in MATLAB Simulink.
  • High gain Bi-directional KY converter for low power EV applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Udumula R.R.

    Article, Energy, 2024, DOI Link

    View abstract ⏷

    In electric vehicles (EVs), the type of electric motor and converter technology have a significant impact on regulating the operational characteristics of the vehicle. Therefore, in this work, the modified bi-directional KY converter (BKYC) is proposed for EV applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, bi-directional power flow, simplified control structure, continuous current, common ground, low volume, and high efficiency. An inductor on either side of the converter ensures continuous current flow and passive components are arranged to operate in series to offer high step-up/step-down conversion. The charging and discharging operations, steady-state analysis, and design process of the proposed converter are discussed in detail and compared with similar bi-directional converter topologies. Further, the efficiency analysis of the proposed converter is presented and found that the efficacy of 95.51 % in charging operation and 96.52 % in discharging operation of operation. The simulations are carried out using MATLAB/Simulink environment. Further, a prototype of a modified bi-directional KY converter is implemented with a TMS320F28335 processor and validated with theoretical and simulation counterparts.
  • Switched Reluctance Motor-based EV Drive with Bidirectional Grid Interaction

    Keshari A., Raveendhra D., Raju B.L.N., Chaturvedi P., Reddy U.R., Bobba P.B.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This manuscript presents a novel Multi-function Switched Reluctance Motor (SRM) based Electric Vehicle (EV) Drive system with integrated Grid-to-Vehicle (G2V) & Vehicle-to-Grid/ Vehicle-to-Load (V2G/V2L) functionalities. The study focuses on the development of a Hybrid Energy Storage System (HESS) that combines the advantages of batteries and super-capacitors to enhance the overall performance and efficiency of EVs. The work begins by discussing the design and integration of the SRM drive system, highlighting its ability to provide multi-functionality while maintaining high levels of efficiency and reliability. The integration of G2V and V2G/V2L functions further enhances the flexibility and usability of the system, allowing for bidirectional power flow between the vehicle and the grid or other loads. One of the key contributions of this work is the development of a comprehensive model for the HESS, which takes into account the characteristics of both the battery and super-capacitor components. This model serves as a universal framework for evaluating different HESS configurations and optimizing their performance based on specific application requirements. The paper also discusses the extensive testing and analysis conducted to validate the proposed HESS system. Results demonstrate the high degree of efficiency achieved by the system, leading to extended battery life and improved overall energy management in EVs. Moreover, the HESS model proves to be versatile, offering insights into power characteristics and aiding in the customization of battery configurations and controller settings.
  • Bidirectional AC-DC Converter System for Grid-to-Vehicle and Vehicle-to-Grid Applications

    Revanth Sai R., Hemanth Kumar M., Dual M.A., Lakshmi S., Tewari S.V., Udumula R.R.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    This paper presents a bidirectional AC-DC converter system designed for seamless power exchange between electric vehicles (EVs) and the utility grid. The proposed converter facilitates the conversion of 230 V, 50 Hz AC input to 380 V DC during grid-to-vehicle operation, allowing for efficient battery charging through a bidirectional DC-DC converter. Conversely, during vehicle-to-grid operation, it converts the 380 V DC input from the DC-DC converter to 230 V, 50 Hz AC output for grid supply. The system employs PI controllers to ensure precise voltage and current regulation, ensuring stable and efficient operation during grid interaction. Simulation results demonstrate the system’s effectiveness in managing power conversion for both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) applications.
  • A Novel Zero Voltage Switching Full Bridge Converter for Multiple Load Battery Fed LED Driver Applications

    Patakamoori A., Udumula R.R., Nizami T.K., Reddy Ch K.R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    A novel zero-voltage switching full-bridge (NZVSFB) converter designed for multiple load LED driver applications is introduced in this paper. Four LED lamps are involved in this configuration, with Lamp-2, Lamp-3, and Lamp-4 being powered by a full bridge converter, and Lamp-l being directly connected in series with the battery source. The efficiency of the system is increased since the power provided to lamp-l comes directly from a battery source, eliminating the need for any power processing stage. The major claims of the proposed NZVSFB converter are low component count/lamp, enhanced efficiency, zero voltage switching (ZVS) of all the switching devices, ripple free current and equal current sharing. The interleaved technique utilized in inductor design aims to mitigate the adverse effects of ripple currents on LED performance and circuit reliability by reducing their magnitude and ensuring more stable operation. The steady state operation of the proposed NZVSFB converter is discussed in detail and the effectiveness of the circuit is verified in MATLAB Simulink environment.
  • Smart Home Energy Management with a Coordinated Neighborhood Energy Sharing

    Ravivarma K., Lokeshgupta B., Ramanjaneya Reddy U.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    The rapid increase in demand for electricity and the emergence of the smart grid have dealt with optimistic opportunities for home energy management systems. The smart home with the integration of renewable energy sources such as photovoltaic systems, micro-wind turbines, and battery storage can provide in-house power generation and also give the option of exporting power to the grid. This paper mainly proposes a centralized coordinated neighborhood power-sharing with incentive-based energy management for multiple smart home consumers. The incentive method and various pricing schemes like time of use and feed-in tariff are considered in this paper to determine the electricity billing of all smart home consumers. Due to these incentives and pricing schemes in this model, all smart home consumers are encouraged to be involved in neighborhood energy sharing. A group of ten smart homes with various load profiles and RER energy integration is considered as a test system to determine the performance of the proposed neighborhood smart home energy management model. The simulation results show that the centralized neighborhood-coordinated smart home energy management model can provide significant economic benefits to all smart home consumers when compared to the without neighborhood power-sharing case.
  • Experimental Investigation on Backstepping Control of DC-DC Buck Converter Fed Constant Power Load

    Gangula S.D., Nizami T.K., Udumula R.R.

    Conference paper, IFAC-PapersOnLine, 2024, DOI Link

    View abstract ⏷

    In contemporary energy production, there's been a significant transition from coal-centric methods to renewable energy sources (RES) that emit zero pollutants. As RES becomes more integral to expansive power systems, there's a growing need for regulated power electronic systems. When integrated with microgrids, RES often face stability challenges, being represented in DC microgrids as a constant power load (CPL). The DC-DC converters designed to operate these CPL loads are affected by switching irregularities and the destabilizing effects of CPL, leading to broader power system instability. This study introduces a backstepping control (BSC) approach for a DC-DC buck converter operating with CPL. Through extensive experimental investigations, the effectiveness of the proposed controller under various test conditions, contrasting its results with the cascade PI controller have been evaluated. The outcomes reveal that the proposed backstepping control technique enhances both the dynamic and steady-state performance of the DC-DC buck converter-CPL system, especially during extensive fluctuations in the load power.
  • A Three Leg Asymmetrical Voltage Resonant Converter With Independent Dimming Control for Multiple Load LED Lighting Applications

    Udumula R.R., Vijayan M., Reddy C.K.R., Syed M., Patakamoori A., Gopichand B.

    Article, IEEE Transactions on Industry Applications, 2024, DOI Link

    View abstract ⏷

    LED lighting has emerged as a global solution for sustainable industrial lighting. The three-leg asymmetrical voltage resonant converter has been designed for optimal performance in dimmable Light-emitting diode (LED) lighting applications. Its distinctive features, including enhanced efficiency, asymmetrical voltage regulation, Zero Voltage Switching (ZVS) of all power switches, and an independent dimming control strategy, make it well-suited for high-power LED lighting applications. The converter under consideration incorporates a common leg-1 to drive load-1 and load-2. So that, the load-1 and load-2 are powered by the asymmetrical voltage between leg-1 and leg-2, and leg-1 and leg-3 respectively. To enable independent dimming control, the voltages between legs are nullified by individual dimming levels. The proposed circuit incorporates two resonant circuits. This configuration ensures that all power switches operate with ZVS, effectively minimizing switching losses. Further, the threshold voltage of each LED load is supplied by the battery in turn resulting in a lower power processing of the converter. The detailed operational principle and design considerations are discussed. Moreover, the loss analysis, detailed comparison with similar works, and the efficiency analysis at different dimming conditions are presented. Finally, the effectiveness of the converter is verified in a MATLAB Simulink environment and an 80W laboratory prototype.
  • Adaptive neural network control of DC–DC power converter

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A., Singh P.

    Article, Expert Systems with Applications, 2023, DOI Link

    View abstract ⏷

    This article proposes a novel Zernike radial neural network based adaptive control architecture for closed-loop control of output DC voltage in DC–DC buck power converter. The proposed combination of novel Zernike radial neural network estimator and the adaptive backstepping controller effectively compensates for wide range of perturbations affecting the converter system, in an online manner. The closed loop stability of the DC–DC buck power converter with the proposed neuro-adaptive backstepping controller is shown using Lyapunov stability criterion. Numerical simulations are conducted to examine the effectiveness of the proposed controller under start-up response and step changes in the load, source voltage and reference output voltage. Furthermore, the simulation findings are validated by conducting extensive real-time investigation on a laboratory prototype, under a wide range of operating points. The results obtained show a significant improvement in the transient response of both output voltage and inductor current of the converter, relative to the relevant control methods proposed in the recent past.
  • Comparative Analysis of Resonant Converter Topologies for Multiple Load Light Emitting Diode Applications

    Patakamoori A., Udumula R.R., Nizami T.K., Meesala R.E.K.

    Conference paper, Lecture Notes in Electrical Engineering, 2023, DOI Link

    View abstract ⏷

    The Light Emitting Diodes (LEDs) are gaining more importance in several lighting applications due to their advantages, such as high efficiency, long life, and environment friendliness, over conventional lighting sources. The driver circuit is a significant component in an LED lighting system to provide regulated power to the lamp. Numerous, DC-DC converter topologies have been proposed for LED lighting applications. Under which low- and medium-power lighting applications such as domestic lighting, traffic lighting, and decorative lighting, non-isolated driver circuits are more beneficial. However, in high-power applications such as street lighting and industrial lighting, isolated and soft switching converters are mostly used as LED driver circuits. Due to high-power capability, reduced switching losses, less component count, high frequency of operation, and high efficiency, soft switching converters are drawing more attention in high-power applications. This paper presents a comparative analysis of resonant LED driver topologies proposed for multiple load lighting applications. Simulations of a few full bridge LED driver topologies have been carried out using MATLAB/Simulink environment. Various performance parameters are evaluated, and finally, conclusions are drawn.
  • Enhanced Predictive Torque Control of Open Winding Permanent Magnet Synchronous Motor Drive with Common Mode Voltage Elimination

    Meesala R.E.K., Athikkal S., Ramanjaneya Reddy U., Kedika N.R.

    Book chapter, Lecture Notes in Electrical Engineering, 2023, DOI Link

    View abstract ⏷

    Nowadays, Predictive Torque Control (PTC) strategy is recognized as a strong tool for controlling the motor drive. Intuitive and multi-objective controlling are significant benefits of PTC. Owing to these benefits, its application is introduced for Open Winding Permanent Magnet Synchronous Motor (OW-PMSM) drive. The basic PTC operated OW-PMSM drive consequences high Common Mode Voltage (CMV) and leads to early failure of motor bearings. In this paper, CMV elimination is proposed for OW-PMSM drive using voltage vector selection in PTC operation. In proposed PTC, the possible voltage vectors (VVs) are identified to gain zero CMV and preselected as prediction VVs for cost-function evaluation. From cost-function evaluation, optimal VV is considered for controlling OW-PMSM drive. In addition, decrease in switching frequency is achieved through proper utilization of optimal VV’s redundant switching states. Therefore, the overall modifications in proposed PTC of OW-PMSM drive ensure simple operational control, CMV elimination, and switching frequency and loss reduction. The claims of proposed PTC are verified through Matlab/Simulink platform and its proficiency is highlighted against basic PTC operation. Thus, the enhanced operation of proposed PTC for OW-PMSM drive with zero CMV is justified.
  • Real-Time Implementation of Laguerre Neural Network-Based Adaptive Control of DC-DC Converter

    Gangula S.D., Nizami T.K., Ramanjaneya Reddy U., Singh P.

    Conference paper, Lecture Notes in Networks and Systems, 2023, DOI Link

    View abstract ⏷

    Applications of power electronic converters have increased invariably in fields of engineering such as robotics, e-mobility and smart grids. DC-DC converters are employed as a switching devices to obtain a required amount of DC voltage in various industrial applications. Under the class of non-isolated DC-DC power converters, the buck converters are of specific interest, as they provide lower DC output voltage than the source DC voltage. In order to obtain a faithful output voltage tracking despite disturbances affecting the system, the converter is connected in the closed feedback loop. In this respect, this paper presents the design, development and experimental findings of Laguerre neural network driven adaptive control of DC-DC buck power converter. The stability of the proposed controller is established through Lyapunov stability criterion. Further, the results are compared with adaptive backstepping control method, by subjecting the converter to start-up test, step changes in the load resistance, input voltage and reference voltage tests. Thereafter, the performance is evaluated on DSP-based dSPACE 1104 processor in the laboratory. Finally, the results are compared in terms of settling time of output voltage state. The results indicate an enhanced dynamic performance of both output voltage and inductor current with the action of proposed controller, thus making it suitable for fast practical applications.
  • Three-Leg Asymmetrical Voltage Resonant Converter for Multiple LED Load Applications with Independent Dimming Control

    Syed M., Gopichand B., Reddy Udumula R., Kasi Ramakrishna Reddy C.

    Conference paper, 2023 IEEE IAS Global Conference on Emerging Technologies, GlobConET 2023, 2023, DOI Link

    View abstract ⏷

    In this paper a new three-leg asymmetrical voltage resonant converter is proposed for multiple LED load applications. The converter is developed with leg-1 has common for both LED loads. The main contributions of the proposed work are: (1) Independent dimming control of LED loads, (2) Zero Voltage Switching (ZVS) of all the power switches, (3) High efficiency and (4) Regulation with asymmetrical voltage control. To achieve independent dimming control, the PWM dimming is employed with leg-2 and leg-3. Two resonant circuits are connected in the proposed circuit. Owing to this all the power switches operate with zero voltage switching which reduces the switching losses, resulting in higher converter efficiency. The loads can be regulated using asymmetrical voltage control. The threshold voltage for the LED loads is supplied with battery source, therefore power processing of converter is reduced. The operating modes and steady-state analysis of the proposed converter are presented in detail and verified by using the MATLAB Simulink environment.
  • Soft-switched full-bridge converter for LED lighting applications with reduced switch current

    Patakamoori A., Udumula R.R., Nizami T.K., Ch K.R.R., Padmanaban S.

    Article, International Journal of Circuit Theory and Applications, 2023, DOI Link

    View abstract ⏷

    Lighting systems using light-emitting diode (LED) have drawn significant attention across the world. This is due to their promising features such as high energy efficiency, reduced greenhouse gas emission, and eco-friendly nature. However, these systems require constant current regulators to provide constant illumination. This article proposes a soft-switched full-bridge LED driver circuit for dc-grid applications with dimming control operation. The circuit consists of a soft-switched full-bridge converter to power different LED lamps with reduced device count from dc-grid voltage. The semiconductor switches of the full-bridge converter conduct a small current during on time due to interleaved inductor and equal current sharing of lamp-2 and lamp-3. This feature reduces the conduction losses. In addition, the proposed converter yields less component count per lamp, dimming operation through on–off control and zero voltage switching, which results in low switching losses. The detailed steady-state analysis of the proposed converter for dc-grid applications with dimming control operation is presented in this work. The performance of the proposed converter is compared with other similar topologies available in the recent literature. Numerical simulations and real-time experimental validations are conducted to evaluate the steady-state performance of the proposed converter topology for LED applications, driving multiple lamp loads from dc-grid. It has been established that the efficiency of the proposed full-bridge converter is 97.52% at the rated power.
  • Development of enhanced direct torque control for surface-mounted permanent magnet synchronous motor drive operation

    Meesala R.E.K., Udumula R.R., Nizami T.K., Hosseinpour A.

    Article, IET Power Electronics, 2023, DOI Link

    View abstract ⏷

    Direct torque control (DTC) is one of the most prominent control techniques used by permanent magnet synchronous motor (PMSM) drives in industry applications. Nevertheless, the presence of hysteresis controllers and inaccurate voltage switching table in traditional DTC results in higher torque and flux ripple. This study proposes an enhanced DTC functioned Surface-mounted PMSM (S-PMSM) drive with mitigation of torque and flux ripple. The operation relies on generating the reference voltage vector (VV) in a stationary reference frame, which supports control of torque and flux without hysteresis controllers. The reference VV generation is simple and does not affect control robustness. The position of reference VV in a sector is used to build the voltage vector (VV) switching table. As a result, the application of nearest discrete VV to reference VV produces optimal torque and flux control. Moreover, redundant switching combinations of null VV are effectively used for possible minimization of switching frequency of two-level voltage source inverter (VSI) supplied S-PMSM drive. Therefore, proposed DTC gains improved S-PMSM drive response along with switching frequency reduction. In dSPACE-RTI 1104 platform, experimental response of S-PMSM drive under various operating conditions have been depicted to highlight the proficiency of proposed DTC in comparison with existing DTC.
  • An Efficient Soft-Switched LED Driver for Street Lighting Applications with Input Regulation

    Patakamoori A., Udumula R.R., Nizami T.K., Ch K.R.R.

    Article, IEEE Journal of Emerging and Selected Topics in Power Electronics, 2023, DOI Link

    View abstract ⏷

    In this article, an efficient soft-switched light emitting diode (LED) driver with input regulation is proposed. The converter drives multiple lamps, and it is divided into two sections. Lamp-2 and lamp-3 are driven by a full bridge converter (FBC), while lamp-1 is placed in series with the input dc voltage source. Power is delivered to lamp-1 without passing through the FBC, which results in improved efficiency. The main benefits of the presented LED driver are: 1) lower current ratings of the FBC switches; 2) ripple-free lamp currents; 3) zero voltage switching (ZVS); 4) high power efficiency; 5) drives multiple lamps; 6) input regulation for source variation; and 7) lower components per lamp. To reduce the current rating of FBC switches, two identical lamps are powered using interleaved inductors. Owing to this, the lamps experience ripple-free currents. Further, due to this, the ZVS is achieved which results in high efficiency. A closed-loop buck-boost converter will compensate for the variations in input by adjusting the duty cycle. The converter operating modes, steady state, and efficiency analysis are discussed in detail. Moreover, to indicate the performance of the converter, a 130 W prototype is built, and experimental results are presented.
  • Comparative Study of Various DC-DC Converter Topologies for PV Powered EV Charging Stations

    Vijayan M., Ramanjaneya Reddy U., Mahto T.

    Conference paper, ECS Transactions, 2022, DOI Link

    View abstract ⏷

    There is a drift in the automotive industry from conventional internal combustion engines (ICE) to Electric Vehicles (EV's). This drift from ICE to EV's counts to the reduced carbon emission and thus reducing the environmental pollution. EV's also finds a solution for increasing fossil fuel costs. When it comes to renewable energy sources, typically solar energy it is affluent and reliable. The usefulness of solar energy is maximized by the incorporation of advanced power converter topologies along with their advanced controls. This paper aims to compare some of the boost converter topologies that are used in EV applications with solar photo voltaic-powered charging stations. The comparative study is conducted on various parameters such as DC voltage gain, duty cycle, efficiency, voltage stress, merits, and demerits. Simulation results are analyzed and compared using the MATLAB/Simulink platform.
  • Optimal PI-Controller-Based Hybrid Energy Storage System in DC Microgrid

    Vijayan M., Udumula R.R., Mahto T., Lokeshgupta B., Goud B.S., Kalyan C.N.S., Balachandran P.K., C D., Padmanaban S., Twala B.

    Article, Sustainability (Switzerland), 2022, DOI Link

    View abstract ⏷

    Power availability from renewable energy sources (RES) is unpredictable, and must be managed effectively for better utilization. The role that a hybrid energy storage system (HESS) plays is vital in this context. Renewable energy sources along with hybrid energy storage systems can provide better power management in a DC microgrid environment. In this paper, the optimal PI-controller-based hybrid energy storage system for a DC microgrid is proposed for the effective utilization of renewable power. In this model, the proposed optimal PI controller is developed using the particle swarm optimization (PSO) approach. A 72 W DC microgrid system is considered in order to validate the effectiveness of the proposed optimal PI controller. The proposed model is implemented using the MATLAB/SIMULINK platform. To show the effectiveness of the proposed model, the results are validated with a conventional PI-controller-based hybrid energy storage system.
  • Legendre Neural Network based Intelligent Control of DC-DC Step Down Converter-PMDC Motor Combination

    Nizami T.K., Gangula S.D., Reddy R., Dhiman H.S.

    Conference paper, IFAC-PapersOnLine, 2022, DOI Link

    View abstract ⏷

    Angular velocity control in DC-DC converter-driven direct current (DC) motors exhibit several challenges in numerous applications. This article proposes a novel single functional layer Legendre neural network integrated adaptive backstepping control technique for the DC-DC step down converter-permanent magnet DC (PMDC) motor system. The proposed controller first aims to estimate the uncertainties in an online mode and then compensate the same efficiently during the robust control action. The closed loop feedback stability of the entire system under the action of proposed controller and the online adaptive learning laws are proved using Lyapunov stability criterion. Further, the proposed controller is numerically simulated for various test conditions including; (a) startup response, (b) a step change in the load torque and (c) reference angular velocity tracking. The transient performance measures of angular velocity such as peak overshoot, peak undershoot and settling time have been observed under the proposed control design and compared with the response obtained from proportional-integral-derivative (PID) controller. Finally, the results presented demonstrate the efficacy of the proposed controller in yielding an enhanced performance under both nominal and perturbed test conditions over a wide operating range.
  • High Gain Boost Converter Fed Single-Phase Sine Pulse Width Modulated Inverter

    Kotana R., Bindu S.K.H., Udumula R.R., Goud B.S.

    Article, International Journal of Renewable Energy Research, 2022, DOI Link

    View abstract ⏷

    A high gain boost converter fed single-phase voltage source inverter with its control for DC to AC power conversion in uninterrupted power supply and renewable energy applications is presented in this paper. The conventional DC-DC boost converter with a coupled inductor and switched capacitor is utilized to obtain high gain. Further, the output voltage of the inverter is controlled by sinusoidal pulse width modulation technique. The detailed design and analysis of high gain boost converter fed single-phase voltage source inverter is also presented. The sine pulse width modulation control scheme for the voltage source inverter is developed and presented. In order to validate the high gain boost converter fed single-phase voltage source inverter, the simulation model is developed in LTspice software environment and results are validated. The results show high gain boost converter achieves a gain of about 10 and the single-phase voltage source inverter is able to provide a rms voltage of 228 V without using the step-up transformer. The total harmonic distortion of output current is found to be reduced below 4%. Further, the results obtained are found to be in close agreement with theoretical values.
  • Seagull Optimization Algorithm–Based Fractional-Order Fuzzy Controller for LFC of Multi-Area Diverse Source System With Realistic Constraints

    Naga Sai Kalyan C.H., Goud B.S., Reddy C.R., Udumula R.R., Bajaj M., Sharma N.K., Elgamli E., Shouran M., Kamel S.

    Article, Frontiers in Energy Research, 2022, DOI Link

    View abstract ⏷

    This study initiates the implementation of fractional-order (FO) fuzzy (F) PID (FOFPID) controller fine-tuned using a seagull optimization algorithm (SOA) for the study of load frequency control (LFC). Initially, the SOA-tuned FOFPID regulator is implemented on the widely utilized model of dual-area reheat-thermal system (DARTS), named test system-1 in this work for a perturbation of 10% step load (10% SLP) on area-1. Dynamical analysis of the DARTS system reveals the viability of the SOA-tuned FOFPID control scheme in regulating frequency deviations effectively compared to other control schemes covered in the literature. Later, the presented regulator is implemented on the multi-area diverse sources (MADS) system possessing realistic constraints in this study, termed test system-2. The sovereignty of the presented FOFPID controller is once again evidenced with controllers of PID/FOPID/FPID fine-tuned with the SOA approach. Moreover, the effect of considering practical realistic nonlinearity constraints such as communication time delays (CTDs) on MADS system performance is visualized and the necessity of its consideration is demonstrated. Furthermore, AC-DC lines are incorporated with the MADS system to enhance the performance under heavy-load disturbances and the robustness of the proposed regulatory mechanism is deliberated.
  • PV/WT Integrated System Using the Gray Wolf Optimization Technique for Power Quality Improvement

    Goud B.S., Rami Reddy C., Naga Sai kalyan C., Udumula R.R., Bajaj M., Abdul Samad B., Shouran M., Kamel S.

    Article, Frontiers in Energy Research, 2022, DOI Link

    View abstract ⏷

    This paper presents the integration of renewable energy sources such as photovoltaics, wind, and batteries to the grid. The hybrid shunt active power filter (HSHAPF) is optimized with the Gray wolf optimization (GWO) and fractional order proportional integral controller (FOPI) for harmonic reduction under nonlinear and unbalanced load conditions. With the use of GWO, the parameters of FOPI are tuned, which effectively minimizes the harmonics. The proposed model has effectively compensated the total harmonic distortions when compared with without the filter and with the passive filter, the active power filter with a PI controller, and the GWO-FOPI-based controller. The performance of the proposed controller is tested under nonlinear and unbalanced conditions. The parameters of the FOPI controller are better tuned with the GWO technique. The comparative results reflect the best results of GWO-FOPI-based HSHAPF. The suggested controller is built in the MATLAB/Simulink Platform.
  • Selection of Reference Flux Linkage for Direct Torque Control Based Induction Motor Drive in Electric Vehicle Applications

    Singh A.K., Reddy U., Prabhakar K.K., Kumar P.

    Article, SAE International Journal of Alternative Powertrains, 2019, DOI Link

    View abstract ⏷

    The surge in economic activities, in the developing nations, has resulted in rapid expansion of urban centres. This expansion of cities has caused a rapid increase in vehicular traffic, which in turn has caused deterioration of air quality. To overcome the problem of unprecedented air pollution, the governments worldwide have framed policies for faster adoption of electric vehicles. One of the major challenges faced is the development of low-cost drive for these vehicles and keeping the imports to a minimum. As a result of this, the trend is to move away from the permanent magnet-based motor technology and to use induction motor-based drivetrain. For the induction motors to be successful in electric vehicle drivetrain application, it is important to have a robust speed control algorithm. This work aims at adapting a direct torque control technique for induction motor's speed control. The work addresses the impact of reference flux linkage on the operation of an induction motor for direct torque control over a wide range of operation. A Finite Element Analysis based induction motor model is used to obtain values of reference flux linkage. The method uses offline calculations to determine the reference flux linkage, and a lookup table is generated using these flux linkage values. This lookup table is eventually implemented with the direct torque control algorithm. The proposed methodology for selecting reference flux linkage is compared with variable flux technique for various vehicle driving cycles. The comparison shows that the proposed approach gives satisfactory performance (in terms of speed response, torque and flux linkage) over a wide operating speed range. Furthermore, energy consumption analysis for considered driving cycles is also discussed.
  • High step-down dual output light emitting diode driver

    Ramanjaneya Reddy U., Narasimharaju B.L., Koreboina V.B.

    Article, International Journal of Renewable Energy Research, 2017,

    View abstract ⏷

    A conventional power factor correction (PFC) based light emitting diode (LED) drivers composed of two-stage DCDC conversions has several drawbacks such as; increased system size due to more component count, less efficiency and complex control etc. The grid powered LED lighting demand for high step-down conversion because the required voltage level of LED light is very less. Thus, this work proposes a one-switch dual-output (OSDO) coupled-inductor buck (CIB) LED driver. The OSDO-CIB converter can eliminates the drawbacks of conventional counterparts. The proposed OSDO-CIB converter can provide various benefits such as; compact size, high efficiency, less total harmonic distortion (THD), simple control, and a significant reduction in device voltage/current rating due to coupled inductors. The converter is designed with discontinuous conduction mode (DCM) of operation in order to achieve in-phase current and voltage, high power factor (PF) and a low THD. This paper mainly emphasized on detailed operating modes and steady-state analysis of proposed converter. Further, prototype of the converter is built and experimental validations are presented.
  • Single-stage electrolytic capacitor less non-inverting buck-boost PFC based AC-DC ripple free LED driver

    Reddy U.R., Narasimharaju B.L.

    Article, IET Power Electronics, 2017, DOI Link

    View abstract ⏷

    This study proposes electrolytic capacitor (EC) less power factor correction (PFC) light emitting diode (LED) driver with reduced current ripple. Generally PFC LED drivers need massive ECs to diminish output current ripple. The life-span of LED driver significantly reduces due to short life-span of ECs, and hence demands for EC-less LED drivers. The proposed LED driver is composed of non-inverting buck-boost PFC converter and bi-directional converter (BDC) for ripple current cancellation which replace the short-life ECs with long-life film capacitors. The PFC converter is designed with discontinuous conduction mode in order to ensure unity power factor operation. The role of BDC is to absorb second harmonic ac ripple current of PFC converter and allow the dc current to LED load. In addition, the desired BDC output voltage (vcbc) is higher than the PFC output voltage (VLED) irrespective of ac source voltage, hence, simplifies the control complexity. Theoretical analysis and predictions of the system have been validated using MATLAB/Simulink simulation, and experimentally validated with a prototype of 7 W. The results evident that PFC integrated BDC provide reduced ripple current with film capacitor as compared with EC counterpart and hence increase the life-span of LED driver.
  • A Cost-Effective Zero-Voltage Switching Dual-Output LED Driver

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Article, IEEE Transactions on Power Electronics, 2017, DOI Link

    View abstract ⏷

    Coupled-inductor (CI) converters are widely used in the light-emitting diode (LED) lighting applications due to several advantages, such as high step-down conversion, reduced switch/diode stress as compared to conventional buck converters. However, the main drawback of CI buck converter is high-voltage spikes during turn-OFF instant due to the leakage inductance of a CI, which leads to switching device failure. Passive clamp circuits are used to overcome the leakage inductance problem, but these clamp circuit's results in reduced efficiency and increased cost. This paper proposes a high step-down zero-voltage switching dual-output coupled-inductor buck (ZVS-DOCIB) LED driver with dimming control. The proposed LED driver provides various advantages like high step-down conversion, effective recovery of leakage energy, elimination of voltage spikes, reduced switching loss due to ZVS operation of both the switching devices, and less switching device count, particularly for multioutput drivers. Also, ZVS operation provides a significant reduction in switching losses, which results in high efficiency. Furthermore, dimming control is studied to regulate the average output currents. This paper presents design and analysis of the proposed ZVS-DOCIB converter. A prototype of the converter has developed and validated experimentally with simulation counterparts.
  • Modeling and analysis of voltage controlled positive output synchronous buck-boost converter

    Narasimharaju B.L., Bharma G., Koreboina V.B., Reddy U.R.

    Conference paper, 12th IEEE International Conference Electronics, Energy, Environment, Communication, Computer, Control: (E3-C3), INDICON 2015, 2016, DOI Link

    View abstract ⏷

    Now a day's use of portable devices increasing more. Such as cellular phones, digital cameras and high efficient power managing modules etc. are demanding for low output voltage ripple with fast transient response. The terminal voltage of the battery used in portable applications varies particularly depending on state of their charging conditions. In this paper, Li-ion battery is considered that provides 4.2V when it is fully charged and drops to 2.7V when fully discharged. However, the system requires a constant output voltage of 3.3V under varying load conditions. Thus, this work addresses the design and modeling of voltage controlled positive output synchronous buck-boost converter. Simulation model is developed using MATLAB/Simulink and results analysis has been carried out.
  • Improved efficiency coupled inductor-buck AC-DC light emitting diode (LED) driver

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Article, IEICE Electronics Express, 2016, DOI Link

    View abstract ⏷

    This work proposes coupled inductor-buck (CI-B) power factor correction (PFC) LED driver. As compared with conventional buck converters, the proposed CI-B PFC converter has several advantages such as; high step-down conversion, reduced total harmonic distortion (THD), increased efficiency, achieves high power factor (PF), reduced current/voltage stress of switch/diode, and effective switch utilization factor. The proposed converter is designed to operate in discontinuous current mode (DCM) to achieve high power factor (PF) and low THD to comply IEC 61000-3-2 class C standards. In addition, a simple one-loop voltage mode controller (VMC) is implemented to achieve the desired regulated output voltage. A proto-type of 16 Watt converter is built and experimental validations are presented.
  • Unity power factor buck-boost LED driver for wide range of input voltage application

    Reddy U.R., Narasimharaju B.L.

    Conference paper, 12th IEEE International Conference Electronics, Energy, Environment, Communication, Computer, Control: (E3-C3), INDICON 2015, 2016, DOI Link

    View abstract ⏷

    LED lighting sources have been used in several applications than established lighting sources due to their high luminous efficiency, environmental friendly, long life, compact size, and not affected by cold temperature. This paper deals with the design of buck-boost LED driver for wide input voltage applications. The proposed LED driver is a combination of uncontrolled rectifier followed by buck-boost converter. This converter is appropriate for wide input voltage applications from 85 Vac - 265 Vac. Over the line range, this topology accomplishes less total harmonic distortion (THD) and good power factor (PF). Average current control scheme is worn to accomplish improved power factor (PF) with low harmonics of line current. Simulation of buck-boost converter with LED load has been developed using PSIM software for 33.67 W. Load has modelled by connecting 13 LEDs in series by supplying 3.7 V & 0.7 A for each LED. For the proposed LED driver, parameter like power factor (PF) and total harmonic distortion (THD) of source current are assessed, it shows the power factor and THD of source current is very low and satisfies the IEC-61000-3-2 class C limits.
  • Enhanced closed loop voltage control of buck converter for improved performance

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Conference paper, 11th IEEE India Conference: Emerging Trends and Innovation in Technology, INDICON 2014, 2015, DOI Link

    View abstract ⏷

    In this paper, author proposes study of two-loop voltage mode controlled (TVMC) buck converter for improved transient and dynamic performance under line and load disturbances. Buck converter with voltage mode control will improve efficiency, but transient response is sluggish. It requires large filter capacitor. Two-loop voltage control technique is proposed to improve output voltage regulation irrespective of line and load disturbances, and to achieve fast transient response. The two-loop voltage control technique has many advantages over conventional voltage mode control technique, such as fast transient response and reduced peak overshoot etc. Simulation model of TVMC buck converter is developed in MATLAB/Simulink and extensive result analysis has been made. The result analysis shows the effectiveness and significant improvement of the proposed control technique.
  • Optimized dual active bridge Bi-directional DC-DC converter for UPS application

    Narasimharaju B.L., Prahlad V.V., Reddy U.R., Vijay Babu K., Srinivasan P.

    Conference paper, 2014 IEEE International Conference on Power Electronics, Drives and Energy Systems, PEDES 2014, 2014, DOI Link

    View abstract ⏷

    With the growing emphasis on smaller compact and efficient power system there is increasing interest in the possibility of using Bi-directional converters especially in DC based power applications. Having the capability of bilateral power flow, that provides the functionality of two uni-directional converters in single converter unit; Bidirectional converters have the increased industrial applications; demand optimized study of topologies and feasibility, critical feature study for the considered application. This document suggests an optimized implementation of Bidirectional DC-DC converter to fit the present day UPS application. Key issues like compact design, utilisation of transformer core, optimised topology for low power (2.5kW) applications were discussed.
Contact Details

ramanjaneya.r@srmap.edu.in

Scholars

Doctoral Scholars

  • Challa Siva Koti Reddy
  • Ms Dasari Sai Ram Surya Lakshmi Avanthika
  • Mr Kamireddy Ravivarma
  • Ms Maya Vijayan

Interests

  • Control Systems
  • High Gain Converters
  • Power Electronics

Education
2009
B.Tech
Jawaharlal Nehru Technological University
India
2012
M.E.
Bangalore University,
India
2017
Ph.D.
National Institute of Technology
India
Experience
  • Nov 2020 - Till date | Assistant Professor | Department of Electrical and Electronics Engineering | SRM University-AP, Andhra Pradesh, India.
  • Apr 2017 – Nov 2020 | Associate Professor | Department of Electrical and Electronics Engineering | Vardhaman College of Engineering, Hyderabad, India (Study Leave from Nov 2017 – Sep 2018).
  • Nov 2017 – Sep 2018 | Post-Doctoral Fellow | Microelectronics Laboratory | University of Crete, Greece.
  • Dec 2013 – Apr 2017 | Senior Research Fellow | Department of Electrical Engineering | National Institute of Technology Warangal, India.
  • Dec 2012 – Dec 2013, | Assistant Professor | Department of Electrical and Electronics Engineering | Chiranjeevi Reddy Institute of Engineering and Technology, Andhra Pradesh, India.
Research Interests
  • Power Electronics - Converters, PWM Techniques, Applications to Lighting System.
  • High Gain Converters for Renewable Energy Applications.
  • Development of control algorithms for converter fed drives.
Awards & Fellowships
  • 2022 - Research Scholar worked under my guidance secured Gold medal (Feb-2022) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2022 - Research Scholar worked under my guidance secured Gold medal (Sep-2022) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2021 - Undergraduate students worked under my guidance secured Gold medal (Aug-2021) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2021 - Research Scholar worked under my guidance secured Gold medal (Aug-2021) for paper presentations in Research Day organized by SRM University-AP, India.
  • 2017 – Received funding for Post Doctoral Fellow – European Government
  • 2015 – Best Paper award at IEEE INDICON Conference – IEEE Delhi Section
  • 2013 – MHRD Fellowship for Doctoral Study – Government of India
  • 2010 – MHRD Fellowship for Masters Study – Government of India
Memberships
  • Senior Member - IEEE
  • Member – Institute of Engineers
Publications
  • Dual Estimation of State of Charge and State of Health of a Battery: Leveraging Machine Learning and Deep Neural Networks

    Avanthika D.S.R.S.L., Udumula R.R., Lokeshgupta B., Morampudi M.K.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    Accurate estimation of battery state including state of charge (SoC) and state of health (SoH) are crucial for ensuring safety in energy storage applications. The SOC and SOH estimators were independently trained using the same input vector but with different objective functions, no integration between SOC and SOH estimations were explored. In this paper, a unified algorithm, for identifying both SoC and SoH states, is introduced by considering the Bayesian optimization for hyperparameter tuning. This approach allows seamless transition between SoC and SoH estimation without needing separate models for each task. In addition, equipping the dual estimation framework with a unified algorithm for identifying both states would impact the algorithm's complexity. The suggested BiLSTM model reduces complexity in real-time Battery Management System (BMS) applications by eliminating the need for a separate model to estimate SoH. When compared to other machine learning and deep learning models such as Support Vector Machines (SVM), Decision Trees (DT), Random Forest (RF), Radial Basis Function Neural Networks (RBF-NN), Recurrent Neural Networks (RNN), and LSTM, the suggested BiLSTM method demonstrates the highest efficiency. Finally, to verify the proposed method's effectiveness, a comparison among the different evaluation metrics was conducted. The proposed BiLSTM model achieved an average MAE (Mean Absolute Error) of 0.08 and NRMSE (Normalized Root Mean Squared Error) of 0.15 for SoC estimation across various temperatures (5°C, 15°C, 35°C, and 45°C), and an MAE of 3.12 and NRMSE of 0.23 for SoH estimation with a degradation rate of 47% of the cell estimated from the predicted capacity values.
  • Power Factor Correction(PFC) for EV Charger Using PI Controller in G2V Application

    Adari J.V., Tewari S.V., Chakravarty A., Udumula R.R., Sagar G.J., Mahto T.

    Conference paper, 1st International Conference on Sustainable Energy Technologies and Computational Intelligence: Towards Sustainable Energy Transition, SETCOM 2025, 2025, DOI Link

    View abstract ⏷

    This paper presents an AC-DC converter system tailored for grid-to-vehicle (G2V) applications, aimed at facilitating efficient power flow while achieving a Unity power factor (UPF). The system employs a rectifier for AC-DC conversion, which effectively steps up a 230V AC input to a 380V DC output. This DC output can be further regulated using a buck converter to meet specific load requirements. A Proportional-Integral (PI) controller is implemented to oversee the voltage and current regulation, thereby minimizing harmonic distortion and enhancing the overall power factor. By actively managing the input voltage and current, the controller ensures that the system operates within desired parameters, thus optimizing power quality. Comprehensive simulation results validate the system's performance, demonstrating its capability to maintain a UPF in G2V mode. The findings indicate significant reductions in total harmonic distortion (THD), reinforcing the system's effectiveness in managing power quality. This AC-DC converter design not only enhances the efficiency of power flow in electric vehicle charging systems but also contributes to the stability of the grid by minimizing reactive power and harmonics. Overall, this work represents a significant advancement in converter technology for sustainable transportation and energy management.
  • Nonlinear Adaptive Neural Control of Power Converter-Driven DC Motor System: Design and Experimental Validation

    Nizami T.K., Gangula S.D., Udumula R.R., Chakravarty A., Ahmad F., Hosseinpour A.

    Article, Engineering Reports, 2025, DOI Link

    View abstract ⏷

    This article presents an intelligent adaptive neural control scheme to track the output speed trajectory in power converter-driven DC motor system. The proposed technique integrates an adaptive polynomial-neural network with a backstepping strategy to yield a robust control system for output tracking in DC motor. Such a unification of online neural network-based estimation and adaptive control, results in effective regulation of the output across a wide load torque uncertainties, besides yielding a promising transient and steady-state performance. The stability of the entire closed-loop system is ensured through Lyapunov stability criterion. The efficacy of the proposed strategy is revealed through an extensive experimental investigation under various operating points during start-up, step-reference tracking, and external step-load torque disturbances. The real-time experimentation is conducted on a laboratory prototype of power converter-driven DC motor of 200 W, using dspace DS1104 control board with MPC8240 processor. The results obtained confirm an improvement in the transient response of the output speed by significantly reducing the settling time to (Formula presented.) and yielding a steady state behavior with no peak over/undershoots during load disturbances, in contrast to other similar works presented in the literature intended for same the application.
  • Zernike radial basis neural network control of DC–DC power converter driven permanent magnet DC motor: design and experimental validation

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A., Ahmad F.

    Article, Electrical Engineering, 2025, DOI Link

    View abstract ⏷

    This article presents a novel control architecture for an enhanced closed-loop speed tracking of a DC–DC buck power converter fed Permanent Magnet DC motor (PMDC) motor in face of large exogenous load torque uncertainty. The proposed architecture combines a new self learning Zernike radial polynomial neural network (ZRNN) estimator with the backstepping controller. The design involves a computationally simple online learning based ZRNN to rapidly and accurately estimate the unknown large load torque uncertainties. The proposed control solution concurrently guarantees stability and excellent dynamic performance through an effective neural network based estimation and subsequent compensation of unanticipated load torque perturbations over a wide range. The closed loop stability of the DC–DC buck power converter driven PMDC motor and asymptotic speed tracking with the proposed neuro-adaptive controller is proved using the stability theory for non-autonomous systems. The effectiveness of the proposed controller has been investigated through experimentation on an indigenously developed laboratory prototype of 200 W under closed loop operation using digital signal processors. The tests conducted around different operating conditions include the motor start-up response, step variations in the load torque, and step changes in the reference speed. Experimental results demonstrate a significant improvement in the speed tracking performance achieving 48.13% reduction in the settling time and no-change in speed during start-up and load torque perturbations upto 600%, respectively. Experimental validations and extensive tests spanning over a large operating region, substantiate the theoretical claims and real-time suitability of the proposed controller for sensitive applications demanding high performance.
  • Non-isolated High-Gain DC-DC Converter with Moderate Gain for Hybrid Energy System Applications on DC Microgrids

    Vijayan M., Ramanjaneya Reddy U., Mahto T.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    A novel non-isolated High-Gain DC-DC Converter with Moderate Gain for Hybrid Energy System applications on DC Microgrids. The paper proposes a novel high-gain DC-DC converter for Hybrid energy systems such as Solar Photovoltaic (PV) systems, Fuel cells (FC), etc. The converter can replace the necessity of multiple converters for multiple sources. The major contributions are the lower switch voltage stress, High boost gain, multiple input capability, and lower component count as a dual source capability. The design and analysis of ideal and non-ideal conditions of the components are discussed and the individual effects of each component are analyzed. Further, the non-ideal gain and non-ideal efficiency are derived and presented. Also, Simulation results with a rated power of 100W are presented.
  • A Novel High Gain Tertiary Port Boost Converter for Hybrid Energy System Integration

    Vijayan M., Udumula R.R., Mahto T.

    Article, IEEE Transactions on Consumer Electronics, 2025, DOI Link

    View abstract ⏷

    This paper introduces novel high-gain tertiary port boost converter (HGTPBC) designed for hybrid energy sources such as solar photovoltaic (PV) and fuel cells (FC). The converter is employed with dual input sources by facilitating modular converters and accomplishes a high step-up voltage gain by virtue of a voltage multiplier in a DC microgrid, where the prosumers can have an islanded operation. The proposed topology allows home appliances to be powered by multiple energy source without the need for a large storage unit. Key features include continuous input current, reduced normalized voltage stress on switches, expandability for multiple input sources and independent source control. The independent control facilitates the standalone operation with single source during source failure or absence. To evaluate the converter performance, a thorough steady-state analysis, both with and without consideration of nonidealities is carried out. Detailed comparisons with existing converter topologies highlight the advantages of the proposed converter. Moreover, the loss distribution and efficiency analysis of proposed converter are presented and found to be 91.59% efficiency at rated power. Theoretical aspects are validated through hardware testing on a 100W laboratory prototype.
  • Development of bi-directional switched-capacitor DC-DC converter for EV powertrain application

    Mounika Nagabushanam K., Mahto T., Tewari S.V., Udumula R.R., Alotaibi M.A., Malik H., Ustun T.S.

    Article, Engineering Science and Technology, an International Journal, 2025, DOI Link

    View abstract ⏷

    The research presents a novel Bidirectional Switched Capacitor DC-DC (BSCD) Converter and demonstrates its application in integrating a battery with an electric vehicle's (EV) traction motor. During discharging, the motor is powered by the battery through the converter, and during charging, the traction motor functions as a generator, returning the recovered energy to the battery via the converter. The recommended converter employs a two-duty cycle operation to enhance voltage gain while minimizing circuit components. It utilizes a switched capacitor (SC) cell, enhancing the voltage transfer ratio by operating capacitors CS1 and CS2 in parallel or series. The work includes analysis of the converter's steady state, mathematical approach, state-space modelling, stability, and efficiency. The proposed converter achieves an efficiency of 90.66 % in charging mode and 96.6 % in discharging mode, with a Gain Margin of 54.4 dB and Phase Margin of 8.09°, indicating stability. Comparative evaluations with existing BDCs are also provided. The implementation of a closed-loop simulation using MATLAB/Simulink and dSpace software validates the performance of the suggested converter-based drive. Furthermore, an experimental investigation of a 200 W, 30 V/430 V configuration confirms the converter's practical viability.
  • Zero voltage switching with reduced current stress for LED lighting applications

    Rao K.V.G., Kumar M.K., Goud B.S., Udumula R.R., Reddy C.R., Balachandran P.K., Zainuri M.A.A.M., Ramasamy S.

    Article, IET Power Electronics, 2025, DOI Link

    View abstract ⏷

    Lighting systems using light emitting diode (LED) have drawn significant attention across the world. Nevertheless, to maintain a steady light output, these systems necessitate constant current regulators. This article proposes a buck–boost integrated zero voltage switched full-bridge LED converter with low current stress. It powers two identical lamps and a lamp of power rating twice the identical lamp. A direct current voltage source, arranged in series, transmits a portion of light power without conversion. A regulated low power output is provided using a complete bridge converter. The semiconductor switches off the full-bridge converter carry minimal current. This characteristic lowers conduction losses. The suggested converter facilitates dimming operation via on–off control and zero voltage switching, leading to minimal switching losses. Further input voltage of full-bridge converter is modulated to maintain constant LED lamp current. The detailed steady-state analysis and implementation of the proposed full-bridge LED converter with dimming control operation is presented here.
  • Random Forest based Machine Learning Algorithm for Estimating State of Charge in Lithium-ion Batteries

    Avanthika D.S.R.S.L., Lokeshgupta B., Udumula R.R.

    Conference paper, 2025 4th International Conference on Power, Control and Computing Technologies, ICPC2T 2025, 2025, DOI Link

    View abstract ⏷

    This paper proposes a Random Forest (RF) machine learning algorithm-based prediction model for the state of charge (SoC) level of lithium-ion batteries for electric vehicles. To show the effectiveness of the proposed prediction model performance, the RF model has been compared with the other machine learning algorithms such as Support Vector Machines (SVM) and Gradient Boosting (GB) approaches. The dataset includes cell temperature, state of charge (SoC), voltage, and current readings at three different external temperatures-15, 25, and 30 degrees Celsius are considered in this paper to test the performances of the proposed model. After preprocessing of the dataset, 20% of the data was used for testing and the remaining 80% for training purposes. The various metrics such as mean squared error (MSE), mean absolute error (MAE), coefficient of determination (R2), root mean squared error (RMSE), normalized root mean squared error (NRMSE), residual standard error (RSE), and relative absolute error (RAE) are usually preferred to evaluate the performance of the prediction models. The simulation results of the proposed model clearly show the effectiveness of SoC-level estimation for real-time battery management systems (BMS) when compared to other machine learning algorithms. The efficiency of the proposed model is 99% and execution time is less than 5 seconds. The accurate estimation of the SOC of lithium-ion batteries is crucial for optimizing battery performance, ensuring safety, and extending battery life in electric vehicles.
  • Real Time Implementation of Buck Converter Using Optimized Type Compensators

    Gangula S.D., Mukhtar A., Nizami T.K., Chakravarty A., Udumula R.R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This work investigates the application of Artificial Bee Colony (ABC) optimization for the design of Type compensators utilizing the dual-loop control scheme. The proposed Type compensators integrate the ABC optimization for regulating the closed-loop operation of a DC-DC buck converter. Such an integration of ABC optimization, aids in effectively regulating the output voltage and inductor current, besides ensuring enhanced time domain criteria. The proposed dual-loop control scheme consists of a current loop and a voltage loop. The current loop regulates the inductor current and the voltage loop regulates the output voltage. The efficacy of the proposed method is revealed through extensive simulation and experimental investigation under start-up response, step perturbations in external load. The experimentation is conducted on a laboratory prototype using dspace DS1104 control board.
  • Self-learning Controller Design for DC–DC Power Converters with Enhanced Dynamic Performance

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A.

    Article, Journal of Control, Automation and Electrical Systems, 2024, DOI Link

    View abstract ⏷

    This article presents a promising self-learning-based robust control for output voltage tracking in DC–DC buck power converters, particularly for applications demanding high precision performance in face of large load uncertainties. The design involves a computationally simple online single hidden layer neural network, to rapidly estimate the unanticipated load changes and exogenous disturbances over a wide range. The controller is designed within a backstepping framework and utilizes the learnt uncertainty from the neural network for subsequent compensation, to eventually ensure an asymptotic stability of the tracking error dynamics. The results obtained feature a significant improvement of dynamic and steady-state performance concurrently for both output voltage and inductor current in contrast to other competent control strategies lately proposed in the literature for similar applications. Extensive numerical simulations and experimentation on a developed laboratory prototype are carried out to justify the practical applicability and feasibility of the proposed controller. Experimental results substantiate the claims of fast dynamic performance in terms of 94% reduction in the settling time, besides an accurate steady-state tracking for both output voltage and inductor current. Moreover, the close resemblance between computational and experimental results is noteworthy and unveils the immense potential of the proposed control system for technology transfer.
  • Power Factor Correction Buck-Boost Converter for On-Board EV Charging Application

    Udumula R.R., Patnaik S., Nandigama S.K., Dega U.S., Lokeshgupta B., Vemula N.K., Kirankumar N.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    This work presents the power factor correction (PFC) buck-boost converter for on-board electric vehicle (EV) charging applications. The PFC buck-boost converter is designed to operate in discontinuous current conduction mode (DCCM), thus achieving natural PFC for the universal input voltage range. In addition, DCCM operation does not require input voltage or current sensors; as a result, the control is more reliable and economical than continuous current conduction mode (CCCM). Furthermore, the buck-boost converter switch operates in zero current switching (ZCS) which results in reduced switching losses and improves the efficiency. The detailed steady-state analysis, operating modes, and design analysis for DCCM operation are presented. To validate the theoretical studies, a closed-loop voltage mode control of the PFC buck-boost converter is developed and tested in a PSIM software environment. The simulation results uphold the converter analysis and achieve a high power factor and low total harmonic distortion (THD) for the universal input range.
  • A Novel PWM Inverter Powered by Single DC Source for a Multiple Pole Pair Induction Motor

    Nallamekala K.K., Reddy U.R., Mishra P., Vemula N.K., Krishna A.R.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    In this paper, a customized multi-level inverter configuration designed for driving an induction motor with multiple pole pairs is introduced. Within the induction motor, each pole pair winding coil spaced 360° (electrically) apart maintains the same voltage profile. In our case, two windings in a four-pole induction motor are deliberately disconnected. A dual two-level inverter is used to power each half of the winding, so two such inverters are used to feed the entire stator winding of the induction motor as pole pair windings are disconnected. The single DC source used to power these inverters has a magnitude of Vdc/4, or 25% of input voltage DC bus voltage needed to power a typical Neutral Point Clamped five-level inverter. This new Pulse Width Modulation approach is used to cancel the harmonics at first center band while controlling the inverter output voltage. This method successfully lowers torque ripple by reducing current ripple. Furthermore, power balancing problems are eliminated because the single DC source is supplying the entire topology. The capacitor voltage balancing problems are also resolved because this design is derived using only two-level inverters. Very few changes to the design are needed for the suggested topology; the main change is to disconnect winding coils with the same voltage profile. The efficacy of the proposed inverter employing the innovative PWM technique in the linear modulation region is demonstrated by simulation results utilizing a 5-hp four-pole induction motor in MATLAB (Simulink).
  • Independently Controllable Single-Input Dual-Output DC-DC Converter for DC Microgrid Based PV Fed EV Charging Stations

    Vijayan M., Ramanjaneya Reddy U., Mahto T., Narasimharaju B.L., Dogga R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    A new non-isolated single-input dual-output (NI-SIDO) DC-DC converter is proposed in this paper. The converter has the advantage of incorporating multiple outputs for energy storage applications, applicable in DC micro-grid storage systems, Electric vehicular charging stations, battery converters, and renewable energy systems without a filter capacitor. The significant advantage of the converter is it uses the interleaving technique to incorporate the outputs. The voltage stress across the switches and capacitor voltage stress is also reduced drastically. Thus it reduces the capacitor size when compared with the conventional boost converter. A closed-loop control strategy is implemented to control the load voltage as well as the inductor current. The converter is designed, analyzed, implemented, and tested using MATLAB SIMULINK software for 150W. The Simulation results are presented under various operating conditions such as changes in load with solar PV systems. The results from real-time testing are presented with the OPAL-RT system.
  • Control Implementation of BKY Converter for EV Applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Ramanjaneya Reddy U.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This paper proposes BKY converter, which is made to run in continuous conduction mode during both the charging and discharging cycles for low power EV applications. An analysis is conducted on the converter's dynamic behavior, and an approach to control is put forth to manage the power transfer between the traction system and battery in an electric vehicle. The suggested converter is designed using an extracted small-signal model. A significant ripple in the detected current causes switching instability in the current-mode control approaches at low duty ratios. A computation delay occurs when the controller is implemented in the microcontroller. The control algorithm's design takes this into account. A theoretical framework for current and voltage loop gain transfer functions are created using the realistic parameters of a BKY converter. Further, dynamic performance under load variations is explained and validated by simulations.
  • Dynamic Operation of Islanded DC Microgrid with Fuel Cell Using Hybrid Energy Storage Systems

    Vijayan M., Udumula R.R., Mahto T., Bhamidi L.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    Effective utilization of renewable energy sources (RES) is with the better management of their fluctuation nature. Employing hybrid energy storage systems (HESS) in line with the RES will improve the power flow equilibrium in the DC microgrids (DC-MG). In this paper, a PI control-based hybrid energy storage system with a Proton exchange membrane (PEM) fuel cell (FC), battery, and a supercapacitor (SC) for increasing the effectiveness of renewable power in the DC-MG is presented. A validation test is conducted for a 100 W DC microgrid system to verify the effectiveness of the proposed model. The MATLAB/SIMULINK software is used to implement the proposed system.
  • Modified Switched Capacitor-Based Non-isolated Bidirectional DC–DC Converter for Obtaining High VTR

    Nagabushanam K.M., Tewari S.V., Udumula R.R., Mahto T.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    Energy storage systems with a high voltage transfer ratio (VTR) play an important role in integrating modern electric power systems with large-scale renewable energy integration. This article suggests a modified Switched Capacitor non-isolated Bidirectional DC–DC Converter (SCBDC) topology to achieve a high VTR. The presented converter has a simple circuit, simple control, a switched capacitor structure that increases the voltage-gain range, and low-voltage stress on switches, making it suitable for renewable and hybrid energy source electric vehicle applications. Continuous conduction mode is used for the operation principles, steady-state analysis, and extraction of voltage and current equations. Simulation results for the proposed converter were obtained in a MATLAB environment, demonstrating the converter's feasibility.
  • Development of high-gain switched-capacitor based bi-directional converter for electric vehicle applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Udumula R.R., Alotaibi M.A., Malik H., Marquez F.P.G.

    Article, Journal of Energy Storage, 2024, DOI Link

    View abstract ⏷

    High efficiency, high voltage transfer ratio (VTR), and low input ripple current is required in any bidirectional DC-DC converter (BDC) that plays a major role in interfacing batteries in applications like dc microgrids and electric vehicles (EVs). For meeting these requirements, a switched capacitor-based BDC is proposed to interface the battery with a propulsion system via DC Link. It has a simple circuit with only a set of switching operations, High VTR, and lesser ripple current on the low voltage (LV) side are advantages of the proposed High Gain Switched-Capacitor Bi-directional DC-DC Converter (SC-BDC) making it appropriate for use in EVs. The steady-state analysis, design consideration of passive components, loss and efficiency analysis are presented. Finally, the proposed High Gain SC-BDC is compared with few of the existing BDC in the literature. The feasibility of the converter was demonstrated by simulating a 200 W converter and validating results produced in a MATLAB environment.
  • A novel multi-port high-gain bidirectional DC–DC converter for energy storage system integration with DC microgrids

    Vijayan M., Udumula R.R., Mahto T., K.M. R.E.

    Article, Journal of Energy Storage, 2024, DOI Link

    View abstract ⏷

    Bidirectional converters have often been used in numerous applications like DC microgrids, renewable energy, hybrid energy storage systems, electric vehicles, etc. The paper proposes a novel multi-port high-gain (NMPHG) bidirectional DC–DC converter that supports DC microgrid (DC-MG) applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, multiple input ports, lower switch voltage stress, and lower component count owing to the single converter with multiple input ports for DC microgrid applications. The detailed operational principle, analysis, and design considerations of proposed NMPHG bidirectional DC–DC converters are discussed. Furthermore, the loss analysis, detailed comparison with similar works, and efficiency analysis with non-modalities during forward power flow (LV to HV) and reverse power flow (HV to LV) modes are presented. The efficiency of the proposed converter is found to be 93.8% in forward power flow and 92.9% in reverse power flow modes at rated power. Finally, a hardware prototype of the proposed NMPHG bidirectional DC–DC converters is implemented with 100 W in FPF mode and 200 W in RPF mode with a TMS320F28335 processor and validated with theoretical counterparts.
  • A comparative analysis of non-isolated Bi-directional converters for energy storage applications

    Nagabushanam K.M., Tewari S.V., Udumula R.R., Mahto T.

    Review, Engineering Research Express, 2024, DOI Link

    View abstract ⏷

    Bi-directional DC-DC converters (BDC) are required for power flow regulation between storage devices and DC buses in renewable energy based distributed generation systems. The fundamental requirements of the BDC are simple structure, reduced switching components, a wide range of voltage gain, low voltage stress, high efficiency, and reduced size. There are different BDC topologies for various applications based on their requirements in the literature. Various BDC are categorized according to their impedance networks. Isolated BDC converters are large due to high-frequency transformers and hence used for static energy storage applications whereas non-isolated BDC is lightweight and suitable for dynamic applications like electric vehicles. This paper reviews types of non-isolated BDC topologies. The performance of five non-isolated BDC converters under steady state condition is evaluated by using theoretical analysis. On this basis, suitability of BDC for different applications is discussed. Further advantages and limitations of converters are discussed by using comparative analysis. The optimization of BDC for distributed generation systems from the perspectives of wide voltage gain, low electromagnetic interference, low cost with higher efficiency is identified. Theoretical analysis of the converters is validated by simulating 200W converters in MATLAB Simulink.
  • High gain Bi-directional KY converter for low power EV applications

    Nagabushanam K.M., Mahto T., Tewari S.V., Udumula R.R.

    Article, Energy, 2024, DOI Link

    View abstract ⏷

    In electric vehicles (EVs), the type of electric motor and converter technology have a significant impact on regulating the operational characteristics of the vehicle. Therefore, in this work, the modified bi-directional KY converter (BKYC) is proposed for EV applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, bi-directional power flow, simplified control structure, continuous current, common ground, low volume, and high efficiency. An inductor on either side of the converter ensures continuous current flow and passive components are arranged to operate in series to offer high step-up/step-down conversion. The charging and discharging operations, steady-state analysis, and design process of the proposed converter are discussed in detail and compared with similar bi-directional converter topologies. Further, the efficiency analysis of the proposed converter is presented and found that the efficacy of 95.51 % in charging operation and 96.52 % in discharging operation of operation. The simulations are carried out using MATLAB/Simulink environment. Further, a prototype of a modified bi-directional KY converter is implemented with a TMS320F28335 processor and validated with theoretical and simulation counterparts.
  • Switched Reluctance Motor-based EV Drive with Bidirectional Grid Interaction

    Keshari A., Raveendhra D., Raju B.L.N., Chaturvedi P., Reddy U.R., Bobba P.B.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    This manuscript presents a novel Multi-function Switched Reluctance Motor (SRM) based Electric Vehicle (EV) Drive system with integrated Grid-to-Vehicle (G2V) & Vehicle-to-Grid/ Vehicle-to-Load (V2G/V2L) functionalities. The study focuses on the development of a Hybrid Energy Storage System (HESS) that combines the advantages of batteries and super-capacitors to enhance the overall performance and efficiency of EVs. The work begins by discussing the design and integration of the SRM drive system, highlighting its ability to provide multi-functionality while maintaining high levels of efficiency and reliability. The integration of G2V and V2G/V2L functions further enhances the flexibility and usability of the system, allowing for bidirectional power flow between the vehicle and the grid or other loads. One of the key contributions of this work is the development of a comprehensive model for the HESS, which takes into account the characteristics of both the battery and super-capacitor components. This model serves as a universal framework for evaluating different HESS configurations and optimizing their performance based on specific application requirements. The paper also discusses the extensive testing and analysis conducted to validate the proposed HESS system. Results demonstrate the high degree of efficiency achieved by the system, leading to extended battery life and improved overall energy management in EVs. Moreover, the HESS model proves to be versatile, offering insights into power characteristics and aiding in the customization of battery configurations and controller settings.
  • Bidirectional AC-DC Converter System for Grid-to-Vehicle and Vehicle-to-Grid Applications

    Revanth Sai R., Hemanth Kumar M., Dual M.A., Lakshmi S., Tewari S.V., Udumula R.R.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    This paper presents a bidirectional AC-DC converter system designed for seamless power exchange between electric vehicles (EVs) and the utility grid. The proposed converter facilitates the conversion of 230 V, 50 Hz AC input to 380 V DC during grid-to-vehicle operation, allowing for efficient battery charging through a bidirectional DC-DC converter. Conversely, during vehicle-to-grid operation, it converts the 380 V DC input from the DC-DC converter to 230 V, 50 Hz AC output for grid supply. The system employs PI controllers to ensure precise voltage and current regulation, ensuring stable and efficient operation during grid interaction. Simulation results demonstrate the system’s effectiveness in managing power conversion for both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) applications.
  • A Novel Zero Voltage Switching Full Bridge Converter for Multiple Load Battery Fed LED Driver Applications

    Patakamoori A., Udumula R.R., Nizami T.K., Reddy Ch K.R.

    Conference paper, 2024 IEEE 4th International Conference on Sustainable Energy and Future Electric Transportation, SEFET 2024, 2024, DOI Link

    View abstract ⏷

    A novel zero-voltage switching full-bridge (NZVSFB) converter designed for multiple load LED driver applications is introduced in this paper. Four LED lamps are involved in this configuration, with Lamp-2, Lamp-3, and Lamp-4 being powered by a full bridge converter, and Lamp-l being directly connected in series with the battery source. The efficiency of the system is increased since the power provided to lamp-l comes directly from a battery source, eliminating the need for any power processing stage. The major claims of the proposed NZVSFB converter are low component count/lamp, enhanced efficiency, zero voltage switching (ZVS) of all the switching devices, ripple free current and equal current sharing. The interleaved technique utilized in inductor design aims to mitigate the adverse effects of ripple currents on LED performance and circuit reliability by reducing their magnitude and ensuring more stable operation. The steady state operation of the proposed NZVSFB converter is discussed in detail and the effectiveness of the circuit is verified in MATLAB Simulink environment.
  • Smart Home Energy Management with a Coordinated Neighborhood Energy Sharing

    Ravivarma K., Lokeshgupta B., Ramanjaneya Reddy U.

    Conference paper, Lecture Notes in Electrical Engineering, 2024, DOI Link

    View abstract ⏷

    The rapid increase in demand for electricity and the emergence of the smart grid have dealt with optimistic opportunities for home energy management systems. The smart home with the integration of renewable energy sources such as photovoltaic systems, micro-wind turbines, and battery storage can provide in-house power generation and also give the option of exporting power to the grid. This paper mainly proposes a centralized coordinated neighborhood power-sharing with incentive-based energy management for multiple smart home consumers. The incentive method and various pricing schemes like time of use and feed-in tariff are considered in this paper to determine the electricity billing of all smart home consumers. Due to these incentives and pricing schemes in this model, all smart home consumers are encouraged to be involved in neighborhood energy sharing. A group of ten smart homes with various load profiles and RER energy integration is considered as a test system to determine the performance of the proposed neighborhood smart home energy management model. The simulation results show that the centralized neighborhood-coordinated smart home energy management model can provide significant economic benefits to all smart home consumers when compared to the without neighborhood power-sharing case.
  • Experimental Investigation on Backstepping Control of DC-DC Buck Converter Fed Constant Power Load

    Gangula S.D., Nizami T.K., Udumula R.R.

    Conference paper, IFAC-PapersOnLine, 2024, DOI Link

    View abstract ⏷

    In contemporary energy production, there's been a significant transition from coal-centric methods to renewable energy sources (RES) that emit zero pollutants. As RES becomes more integral to expansive power systems, there's a growing need for regulated power electronic systems. When integrated with microgrids, RES often face stability challenges, being represented in DC microgrids as a constant power load (CPL). The DC-DC converters designed to operate these CPL loads are affected by switching irregularities and the destabilizing effects of CPL, leading to broader power system instability. This study introduces a backstepping control (BSC) approach for a DC-DC buck converter operating with CPL. Through extensive experimental investigations, the effectiveness of the proposed controller under various test conditions, contrasting its results with the cascade PI controller have been evaluated. The outcomes reveal that the proposed backstepping control technique enhances both the dynamic and steady-state performance of the DC-DC buck converter-CPL system, especially during extensive fluctuations in the load power.
  • A Three Leg Asymmetrical Voltage Resonant Converter With Independent Dimming Control for Multiple Load LED Lighting Applications

    Udumula R.R., Vijayan M., Reddy C.K.R., Syed M., Patakamoori A., Gopichand B.

    Article, IEEE Transactions on Industry Applications, 2024, DOI Link

    View abstract ⏷

    LED lighting has emerged as a global solution for sustainable industrial lighting. The three-leg asymmetrical voltage resonant converter has been designed for optimal performance in dimmable Light-emitting diode (LED) lighting applications. Its distinctive features, including enhanced efficiency, asymmetrical voltage regulation, Zero Voltage Switching (ZVS) of all power switches, and an independent dimming control strategy, make it well-suited for high-power LED lighting applications. The converter under consideration incorporates a common leg-1 to drive load-1 and load-2. So that, the load-1 and load-2 are powered by the asymmetrical voltage between leg-1 and leg-2, and leg-1 and leg-3 respectively. To enable independent dimming control, the voltages between legs are nullified by individual dimming levels. The proposed circuit incorporates two resonant circuits. This configuration ensures that all power switches operate with ZVS, effectively minimizing switching losses. Further, the threshold voltage of each LED load is supplied by the battery in turn resulting in a lower power processing of the converter. The detailed operational principle and design considerations are discussed. Moreover, the loss analysis, detailed comparison with similar works, and the efficiency analysis at different dimming conditions are presented. Finally, the effectiveness of the converter is verified in a MATLAB Simulink environment and an 80W laboratory prototype.
  • Adaptive neural network control of DC–DC power converter

    Gangula S.D., Nizami T.K., Udumula R.R., Chakravarty A., Singh P.

    Article, Expert Systems with Applications, 2023, DOI Link

    View abstract ⏷

    This article proposes a novel Zernike radial neural network based adaptive control architecture for closed-loop control of output DC voltage in DC–DC buck power converter. The proposed combination of novel Zernike radial neural network estimator and the adaptive backstepping controller effectively compensates for wide range of perturbations affecting the converter system, in an online manner. The closed loop stability of the DC–DC buck power converter with the proposed neuro-adaptive backstepping controller is shown using Lyapunov stability criterion. Numerical simulations are conducted to examine the effectiveness of the proposed controller under start-up response and step changes in the load, source voltage and reference output voltage. Furthermore, the simulation findings are validated by conducting extensive real-time investigation on a laboratory prototype, under a wide range of operating points. The results obtained show a significant improvement in the transient response of both output voltage and inductor current of the converter, relative to the relevant control methods proposed in the recent past.
  • Comparative Analysis of Resonant Converter Topologies for Multiple Load Light Emitting Diode Applications

    Patakamoori A., Udumula R.R., Nizami T.K., Meesala R.E.K.

    Conference paper, Lecture Notes in Electrical Engineering, 2023, DOI Link

    View abstract ⏷

    The Light Emitting Diodes (LEDs) are gaining more importance in several lighting applications due to their advantages, such as high efficiency, long life, and environment friendliness, over conventional lighting sources. The driver circuit is a significant component in an LED lighting system to provide regulated power to the lamp. Numerous, DC-DC converter topologies have been proposed for LED lighting applications. Under which low- and medium-power lighting applications such as domestic lighting, traffic lighting, and decorative lighting, non-isolated driver circuits are more beneficial. However, in high-power applications such as street lighting and industrial lighting, isolated and soft switching converters are mostly used as LED driver circuits. Due to high-power capability, reduced switching losses, less component count, high frequency of operation, and high efficiency, soft switching converters are drawing more attention in high-power applications. This paper presents a comparative analysis of resonant LED driver topologies proposed for multiple load lighting applications. Simulations of a few full bridge LED driver topologies have been carried out using MATLAB/Simulink environment. Various performance parameters are evaluated, and finally, conclusions are drawn.
  • Enhanced Predictive Torque Control of Open Winding Permanent Magnet Synchronous Motor Drive with Common Mode Voltage Elimination

    Meesala R.E.K., Athikkal S., Ramanjaneya Reddy U., Kedika N.R.

    Book chapter, Lecture Notes in Electrical Engineering, 2023, DOI Link

    View abstract ⏷

    Nowadays, Predictive Torque Control (PTC) strategy is recognized as a strong tool for controlling the motor drive. Intuitive and multi-objective controlling are significant benefits of PTC. Owing to these benefits, its application is introduced for Open Winding Permanent Magnet Synchronous Motor (OW-PMSM) drive. The basic PTC operated OW-PMSM drive consequences high Common Mode Voltage (CMV) and leads to early failure of motor bearings. In this paper, CMV elimination is proposed for OW-PMSM drive using voltage vector selection in PTC operation. In proposed PTC, the possible voltage vectors (VVs) are identified to gain zero CMV and preselected as prediction VVs for cost-function evaluation. From cost-function evaluation, optimal VV is considered for controlling OW-PMSM drive. In addition, decrease in switching frequency is achieved through proper utilization of optimal VV’s redundant switching states. Therefore, the overall modifications in proposed PTC of OW-PMSM drive ensure simple operational control, CMV elimination, and switching frequency and loss reduction. The claims of proposed PTC are verified through Matlab/Simulink platform and its proficiency is highlighted against basic PTC operation. Thus, the enhanced operation of proposed PTC for OW-PMSM drive with zero CMV is justified.
  • Real-Time Implementation of Laguerre Neural Network-Based Adaptive Control of DC-DC Converter

    Gangula S.D., Nizami T.K., Ramanjaneya Reddy U., Singh P.

    Conference paper, Lecture Notes in Networks and Systems, 2023, DOI Link

    View abstract ⏷

    Applications of power electronic converters have increased invariably in fields of engineering such as robotics, e-mobility and smart grids. DC-DC converters are employed as a switching devices to obtain a required amount of DC voltage in various industrial applications. Under the class of non-isolated DC-DC power converters, the buck converters are of specific interest, as they provide lower DC output voltage than the source DC voltage. In order to obtain a faithful output voltage tracking despite disturbances affecting the system, the converter is connected in the closed feedback loop. In this respect, this paper presents the design, development and experimental findings of Laguerre neural network driven adaptive control of DC-DC buck power converter. The stability of the proposed controller is established through Lyapunov stability criterion. Further, the results are compared with adaptive backstepping control method, by subjecting the converter to start-up test, step changes in the load resistance, input voltage and reference voltage tests. Thereafter, the performance is evaluated on DSP-based dSPACE 1104 processor in the laboratory. Finally, the results are compared in terms of settling time of output voltage state. The results indicate an enhanced dynamic performance of both output voltage and inductor current with the action of proposed controller, thus making it suitable for fast practical applications.
  • Three-Leg Asymmetrical Voltage Resonant Converter for Multiple LED Load Applications with Independent Dimming Control

    Syed M., Gopichand B., Reddy Udumula R., Kasi Ramakrishna Reddy C.

    Conference paper, 2023 IEEE IAS Global Conference on Emerging Technologies, GlobConET 2023, 2023, DOI Link

    View abstract ⏷

    In this paper a new three-leg asymmetrical voltage resonant converter is proposed for multiple LED load applications. The converter is developed with leg-1 has common for both LED loads. The main contributions of the proposed work are: (1) Independent dimming control of LED loads, (2) Zero Voltage Switching (ZVS) of all the power switches, (3) High efficiency and (4) Regulation with asymmetrical voltage control. To achieve independent dimming control, the PWM dimming is employed with leg-2 and leg-3. Two resonant circuits are connected in the proposed circuit. Owing to this all the power switches operate with zero voltage switching which reduces the switching losses, resulting in higher converter efficiency. The loads can be regulated using asymmetrical voltage control. The threshold voltage for the LED loads is supplied with battery source, therefore power processing of converter is reduced. The operating modes and steady-state analysis of the proposed converter are presented in detail and verified by using the MATLAB Simulink environment.
  • Soft-switched full-bridge converter for LED lighting applications with reduced switch current

    Patakamoori A., Udumula R.R., Nizami T.K., Ch K.R.R., Padmanaban S.

    Article, International Journal of Circuit Theory and Applications, 2023, DOI Link

    View abstract ⏷

    Lighting systems using light-emitting diode (LED) have drawn significant attention across the world. This is due to their promising features such as high energy efficiency, reduced greenhouse gas emission, and eco-friendly nature. However, these systems require constant current regulators to provide constant illumination. This article proposes a soft-switched full-bridge LED driver circuit for dc-grid applications with dimming control operation. The circuit consists of a soft-switched full-bridge converter to power different LED lamps with reduced device count from dc-grid voltage. The semiconductor switches of the full-bridge converter conduct a small current during on time due to interleaved inductor and equal current sharing of lamp-2 and lamp-3. This feature reduces the conduction losses. In addition, the proposed converter yields less component count per lamp, dimming operation through on–off control and zero voltage switching, which results in low switching losses. The detailed steady-state analysis of the proposed converter for dc-grid applications with dimming control operation is presented in this work. The performance of the proposed converter is compared with other similar topologies available in the recent literature. Numerical simulations and real-time experimental validations are conducted to evaluate the steady-state performance of the proposed converter topology for LED applications, driving multiple lamp loads from dc-grid. It has been established that the efficiency of the proposed full-bridge converter is 97.52% at the rated power.
  • Development of enhanced direct torque control for surface-mounted permanent magnet synchronous motor drive operation

    Meesala R.E.K., Udumula R.R., Nizami T.K., Hosseinpour A.

    Article, IET Power Electronics, 2023, DOI Link

    View abstract ⏷

    Direct torque control (DTC) is one of the most prominent control techniques used by permanent magnet synchronous motor (PMSM) drives in industry applications. Nevertheless, the presence of hysteresis controllers and inaccurate voltage switching table in traditional DTC results in higher torque and flux ripple. This study proposes an enhanced DTC functioned Surface-mounted PMSM (S-PMSM) drive with mitigation of torque and flux ripple. The operation relies on generating the reference voltage vector (VV) in a stationary reference frame, which supports control of torque and flux without hysteresis controllers. The reference VV generation is simple and does not affect control robustness. The position of reference VV in a sector is used to build the voltage vector (VV) switching table. As a result, the application of nearest discrete VV to reference VV produces optimal torque and flux control. Moreover, redundant switching combinations of null VV are effectively used for possible minimization of switching frequency of two-level voltage source inverter (VSI) supplied S-PMSM drive. Therefore, proposed DTC gains improved S-PMSM drive response along with switching frequency reduction. In dSPACE-RTI 1104 platform, experimental response of S-PMSM drive under various operating conditions have been depicted to highlight the proficiency of proposed DTC in comparison with existing DTC.
  • An Efficient Soft-Switched LED Driver for Street Lighting Applications with Input Regulation

    Patakamoori A., Udumula R.R., Nizami T.K., Ch K.R.R.

    Article, IEEE Journal of Emerging and Selected Topics in Power Electronics, 2023, DOI Link

    View abstract ⏷

    In this article, an efficient soft-switched light emitting diode (LED) driver with input regulation is proposed. The converter drives multiple lamps, and it is divided into two sections. Lamp-2 and lamp-3 are driven by a full bridge converter (FBC), while lamp-1 is placed in series with the input dc voltage source. Power is delivered to lamp-1 without passing through the FBC, which results in improved efficiency. The main benefits of the presented LED driver are: 1) lower current ratings of the FBC switches; 2) ripple-free lamp currents; 3) zero voltage switching (ZVS); 4) high power efficiency; 5) drives multiple lamps; 6) input regulation for source variation; and 7) lower components per lamp. To reduce the current rating of FBC switches, two identical lamps are powered using interleaved inductors. Owing to this, the lamps experience ripple-free currents. Further, due to this, the ZVS is achieved which results in high efficiency. A closed-loop buck-boost converter will compensate for the variations in input by adjusting the duty cycle. The converter operating modes, steady state, and efficiency analysis are discussed in detail. Moreover, to indicate the performance of the converter, a 130 W prototype is built, and experimental results are presented.
  • Comparative Study of Various DC-DC Converter Topologies for PV Powered EV Charging Stations

    Vijayan M., Ramanjaneya Reddy U., Mahto T.

    Conference paper, ECS Transactions, 2022, DOI Link

    View abstract ⏷

    There is a drift in the automotive industry from conventional internal combustion engines (ICE) to Electric Vehicles (EV's). This drift from ICE to EV's counts to the reduced carbon emission and thus reducing the environmental pollution. EV's also finds a solution for increasing fossil fuel costs. When it comes to renewable energy sources, typically solar energy it is affluent and reliable. The usefulness of solar energy is maximized by the incorporation of advanced power converter topologies along with their advanced controls. This paper aims to compare some of the boost converter topologies that are used in EV applications with solar photo voltaic-powered charging stations. The comparative study is conducted on various parameters such as DC voltage gain, duty cycle, efficiency, voltage stress, merits, and demerits. Simulation results are analyzed and compared using the MATLAB/Simulink platform.
  • Optimal PI-Controller-Based Hybrid Energy Storage System in DC Microgrid

    Vijayan M., Udumula R.R., Mahto T., Lokeshgupta B., Goud B.S., Kalyan C.N.S., Balachandran P.K., C D., Padmanaban S., Twala B.

    Article, Sustainability (Switzerland), 2022, DOI Link

    View abstract ⏷

    Power availability from renewable energy sources (RES) is unpredictable, and must be managed effectively for better utilization. The role that a hybrid energy storage system (HESS) plays is vital in this context. Renewable energy sources along with hybrid energy storage systems can provide better power management in a DC microgrid environment. In this paper, the optimal PI-controller-based hybrid energy storage system for a DC microgrid is proposed for the effective utilization of renewable power. In this model, the proposed optimal PI controller is developed using the particle swarm optimization (PSO) approach. A 72 W DC microgrid system is considered in order to validate the effectiveness of the proposed optimal PI controller. The proposed model is implemented using the MATLAB/SIMULINK platform. To show the effectiveness of the proposed model, the results are validated with a conventional PI-controller-based hybrid energy storage system.
  • Legendre Neural Network based Intelligent Control of DC-DC Step Down Converter-PMDC Motor Combination

    Nizami T.K., Gangula S.D., Reddy R., Dhiman H.S.

    Conference paper, IFAC-PapersOnLine, 2022, DOI Link

    View abstract ⏷

    Angular velocity control in DC-DC converter-driven direct current (DC) motors exhibit several challenges in numerous applications. This article proposes a novel single functional layer Legendre neural network integrated adaptive backstepping control technique for the DC-DC step down converter-permanent magnet DC (PMDC) motor system. The proposed controller first aims to estimate the uncertainties in an online mode and then compensate the same efficiently during the robust control action. The closed loop feedback stability of the entire system under the action of proposed controller and the online adaptive learning laws are proved using Lyapunov stability criterion. Further, the proposed controller is numerically simulated for various test conditions including; (a) startup response, (b) a step change in the load torque and (c) reference angular velocity tracking. The transient performance measures of angular velocity such as peak overshoot, peak undershoot and settling time have been observed under the proposed control design and compared with the response obtained from proportional-integral-derivative (PID) controller. Finally, the results presented demonstrate the efficacy of the proposed controller in yielding an enhanced performance under both nominal and perturbed test conditions over a wide operating range.
  • High Gain Boost Converter Fed Single-Phase Sine Pulse Width Modulated Inverter

    Kotana R., Bindu S.K.H., Udumula R.R., Goud B.S.

    Article, International Journal of Renewable Energy Research, 2022, DOI Link

    View abstract ⏷

    A high gain boost converter fed single-phase voltage source inverter with its control for DC to AC power conversion in uninterrupted power supply and renewable energy applications is presented in this paper. The conventional DC-DC boost converter with a coupled inductor and switched capacitor is utilized to obtain high gain. Further, the output voltage of the inverter is controlled by sinusoidal pulse width modulation technique. The detailed design and analysis of high gain boost converter fed single-phase voltage source inverter is also presented. The sine pulse width modulation control scheme for the voltage source inverter is developed and presented. In order to validate the high gain boost converter fed single-phase voltage source inverter, the simulation model is developed in LTspice software environment and results are validated. The results show high gain boost converter achieves a gain of about 10 and the single-phase voltage source inverter is able to provide a rms voltage of 228 V without using the step-up transformer. The total harmonic distortion of output current is found to be reduced below 4%. Further, the results obtained are found to be in close agreement with theoretical values.
  • Seagull Optimization Algorithm–Based Fractional-Order Fuzzy Controller for LFC of Multi-Area Diverse Source System With Realistic Constraints

    Naga Sai Kalyan C.H., Goud B.S., Reddy C.R., Udumula R.R., Bajaj M., Sharma N.K., Elgamli E., Shouran M., Kamel S.

    Article, Frontiers in Energy Research, 2022, DOI Link

    View abstract ⏷

    This study initiates the implementation of fractional-order (FO) fuzzy (F) PID (FOFPID) controller fine-tuned using a seagull optimization algorithm (SOA) for the study of load frequency control (LFC). Initially, the SOA-tuned FOFPID regulator is implemented on the widely utilized model of dual-area reheat-thermal system (DARTS), named test system-1 in this work for a perturbation of 10% step load (10% SLP) on area-1. Dynamical analysis of the DARTS system reveals the viability of the SOA-tuned FOFPID control scheme in regulating frequency deviations effectively compared to other control schemes covered in the literature. Later, the presented regulator is implemented on the multi-area diverse sources (MADS) system possessing realistic constraints in this study, termed test system-2. The sovereignty of the presented FOFPID controller is once again evidenced with controllers of PID/FOPID/FPID fine-tuned with the SOA approach. Moreover, the effect of considering practical realistic nonlinearity constraints such as communication time delays (CTDs) on MADS system performance is visualized and the necessity of its consideration is demonstrated. Furthermore, AC-DC lines are incorporated with the MADS system to enhance the performance under heavy-load disturbances and the robustness of the proposed regulatory mechanism is deliberated.
  • PV/WT Integrated System Using the Gray Wolf Optimization Technique for Power Quality Improvement

    Goud B.S., Rami Reddy C., Naga Sai kalyan C., Udumula R.R., Bajaj M., Abdul Samad B., Shouran M., Kamel S.

    Article, Frontiers in Energy Research, 2022, DOI Link

    View abstract ⏷

    This paper presents the integration of renewable energy sources such as photovoltaics, wind, and batteries to the grid. The hybrid shunt active power filter (HSHAPF) is optimized with the Gray wolf optimization (GWO) and fractional order proportional integral controller (FOPI) for harmonic reduction under nonlinear and unbalanced load conditions. With the use of GWO, the parameters of FOPI are tuned, which effectively minimizes the harmonics. The proposed model has effectively compensated the total harmonic distortions when compared with without the filter and with the passive filter, the active power filter with a PI controller, and the GWO-FOPI-based controller. The performance of the proposed controller is tested under nonlinear and unbalanced conditions. The parameters of the FOPI controller are better tuned with the GWO technique. The comparative results reflect the best results of GWO-FOPI-based HSHAPF. The suggested controller is built in the MATLAB/Simulink Platform.
  • Selection of Reference Flux Linkage for Direct Torque Control Based Induction Motor Drive in Electric Vehicle Applications

    Singh A.K., Reddy U., Prabhakar K.K., Kumar P.

    Article, SAE International Journal of Alternative Powertrains, 2019, DOI Link

    View abstract ⏷

    The surge in economic activities, in the developing nations, has resulted in rapid expansion of urban centres. This expansion of cities has caused a rapid increase in vehicular traffic, which in turn has caused deterioration of air quality. To overcome the problem of unprecedented air pollution, the governments worldwide have framed policies for faster adoption of electric vehicles. One of the major challenges faced is the development of low-cost drive for these vehicles and keeping the imports to a minimum. As a result of this, the trend is to move away from the permanent magnet-based motor technology and to use induction motor-based drivetrain. For the induction motors to be successful in electric vehicle drivetrain application, it is important to have a robust speed control algorithm. This work aims at adapting a direct torque control technique for induction motor's speed control. The work addresses the impact of reference flux linkage on the operation of an induction motor for direct torque control over a wide range of operation. A Finite Element Analysis based induction motor model is used to obtain values of reference flux linkage. The method uses offline calculations to determine the reference flux linkage, and a lookup table is generated using these flux linkage values. This lookup table is eventually implemented with the direct torque control algorithm. The proposed methodology for selecting reference flux linkage is compared with variable flux technique for various vehicle driving cycles. The comparison shows that the proposed approach gives satisfactory performance (in terms of speed response, torque and flux linkage) over a wide operating speed range. Furthermore, energy consumption analysis for considered driving cycles is also discussed.
  • High step-down dual output light emitting diode driver

    Ramanjaneya Reddy U., Narasimharaju B.L., Koreboina V.B.

    Article, International Journal of Renewable Energy Research, 2017,

    View abstract ⏷

    A conventional power factor correction (PFC) based light emitting diode (LED) drivers composed of two-stage DCDC conversions has several drawbacks such as; increased system size due to more component count, less efficiency and complex control etc. The grid powered LED lighting demand for high step-down conversion because the required voltage level of LED light is very less. Thus, this work proposes a one-switch dual-output (OSDO) coupled-inductor buck (CIB) LED driver. The OSDO-CIB converter can eliminates the drawbacks of conventional counterparts. The proposed OSDO-CIB converter can provide various benefits such as; compact size, high efficiency, less total harmonic distortion (THD), simple control, and a significant reduction in device voltage/current rating due to coupled inductors. The converter is designed with discontinuous conduction mode (DCM) of operation in order to achieve in-phase current and voltage, high power factor (PF) and a low THD. This paper mainly emphasized on detailed operating modes and steady-state analysis of proposed converter. Further, prototype of the converter is built and experimental validations are presented.
  • Single-stage electrolytic capacitor less non-inverting buck-boost PFC based AC-DC ripple free LED driver

    Reddy U.R., Narasimharaju B.L.

    Article, IET Power Electronics, 2017, DOI Link

    View abstract ⏷

    This study proposes electrolytic capacitor (EC) less power factor correction (PFC) light emitting diode (LED) driver with reduced current ripple. Generally PFC LED drivers need massive ECs to diminish output current ripple. The life-span of LED driver significantly reduces due to short life-span of ECs, and hence demands for EC-less LED drivers. The proposed LED driver is composed of non-inverting buck-boost PFC converter and bi-directional converter (BDC) for ripple current cancellation which replace the short-life ECs with long-life film capacitors. The PFC converter is designed with discontinuous conduction mode in order to ensure unity power factor operation. The role of BDC is to absorb second harmonic ac ripple current of PFC converter and allow the dc current to LED load. In addition, the desired BDC output voltage (vcbc) is higher than the PFC output voltage (VLED) irrespective of ac source voltage, hence, simplifies the control complexity. Theoretical analysis and predictions of the system have been validated using MATLAB/Simulink simulation, and experimentally validated with a prototype of 7 W. The results evident that PFC integrated BDC provide reduced ripple current with film capacitor as compared with EC counterpart and hence increase the life-span of LED driver.
  • A Cost-Effective Zero-Voltage Switching Dual-Output LED Driver

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Article, IEEE Transactions on Power Electronics, 2017, DOI Link

    View abstract ⏷

    Coupled-inductor (CI) converters are widely used in the light-emitting diode (LED) lighting applications due to several advantages, such as high step-down conversion, reduced switch/diode stress as compared to conventional buck converters. However, the main drawback of CI buck converter is high-voltage spikes during turn-OFF instant due to the leakage inductance of a CI, which leads to switching device failure. Passive clamp circuits are used to overcome the leakage inductance problem, but these clamp circuit's results in reduced efficiency and increased cost. This paper proposes a high step-down zero-voltage switching dual-output coupled-inductor buck (ZVS-DOCIB) LED driver with dimming control. The proposed LED driver provides various advantages like high step-down conversion, effective recovery of leakage energy, elimination of voltage spikes, reduced switching loss due to ZVS operation of both the switching devices, and less switching device count, particularly for multioutput drivers. Also, ZVS operation provides a significant reduction in switching losses, which results in high efficiency. Furthermore, dimming control is studied to regulate the average output currents. This paper presents design and analysis of the proposed ZVS-DOCIB converter. A prototype of the converter has developed and validated experimentally with simulation counterparts.
  • Modeling and analysis of voltage controlled positive output synchronous buck-boost converter

    Narasimharaju B.L., Bharma G., Koreboina V.B., Reddy U.R.

    Conference paper, 12th IEEE International Conference Electronics, Energy, Environment, Communication, Computer, Control: (E3-C3), INDICON 2015, 2016, DOI Link

    View abstract ⏷

    Now a day's use of portable devices increasing more. Such as cellular phones, digital cameras and high efficient power managing modules etc. are demanding for low output voltage ripple with fast transient response. The terminal voltage of the battery used in portable applications varies particularly depending on state of their charging conditions. In this paper, Li-ion battery is considered that provides 4.2V when it is fully charged and drops to 2.7V when fully discharged. However, the system requires a constant output voltage of 3.3V under varying load conditions. Thus, this work addresses the design and modeling of voltage controlled positive output synchronous buck-boost converter. Simulation model is developed using MATLAB/Simulink and results analysis has been carried out.
  • Improved efficiency coupled inductor-buck AC-DC light emitting diode (LED) driver

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Article, IEICE Electronics Express, 2016, DOI Link

    View abstract ⏷

    This work proposes coupled inductor-buck (CI-B) power factor correction (PFC) LED driver. As compared with conventional buck converters, the proposed CI-B PFC converter has several advantages such as; high step-down conversion, reduced total harmonic distortion (THD), increased efficiency, achieves high power factor (PF), reduced current/voltage stress of switch/diode, and effective switch utilization factor. The proposed converter is designed to operate in discontinuous current mode (DCM) to achieve high power factor (PF) and low THD to comply IEC 61000-3-2 class C standards. In addition, a simple one-loop voltage mode controller (VMC) is implemented to achieve the desired regulated output voltage. A proto-type of 16 Watt converter is built and experimental validations are presented.
  • Unity power factor buck-boost LED driver for wide range of input voltage application

    Reddy U.R., Narasimharaju B.L.

    Conference paper, 12th IEEE International Conference Electronics, Energy, Environment, Communication, Computer, Control: (E3-C3), INDICON 2015, 2016, DOI Link

    View abstract ⏷

    LED lighting sources have been used in several applications than established lighting sources due to their high luminous efficiency, environmental friendly, long life, compact size, and not affected by cold temperature. This paper deals with the design of buck-boost LED driver for wide input voltage applications. The proposed LED driver is a combination of uncontrolled rectifier followed by buck-boost converter. This converter is appropriate for wide input voltage applications from 85 Vac - 265 Vac. Over the line range, this topology accomplishes less total harmonic distortion (THD) and good power factor (PF). Average current control scheme is worn to accomplish improved power factor (PF) with low harmonics of line current. Simulation of buck-boost converter with LED load has been developed using PSIM software for 33.67 W. Load has modelled by connecting 13 LEDs in series by supplying 3.7 V & 0.7 A for each LED. For the proposed LED driver, parameter like power factor (PF) and total harmonic distortion (THD) of source current are assessed, it shows the power factor and THD of source current is very low and satisfies the IEC-61000-3-2 class C limits.
  • Enhanced closed loop voltage control of buck converter for improved performance

    Ramanjaneya Reddy U., Narasimharaju B.L.

    Conference paper, 11th IEEE India Conference: Emerging Trends and Innovation in Technology, INDICON 2014, 2015, DOI Link

    View abstract ⏷

    In this paper, author proposes study of two-loop voltage mode controlled (TVMC) buck converter for improved transient and dynamic performance under line and load disturbances. Buck converter with voltage mode control will improve efficiency, but transient response is sluggish. It requires large filter capacitor. Two-loop voltage control technique is proposed to improve output voltage regulation irrespective of line and load disturbances, and to achieve fast transient response. The two-loop voltage control technique has many advantages over conventional voltage mode control technique, such as fast transient response and reduced peak overshoot etc. Simulation model of TVMC buck converter is developed in MATLAB/Simulink and extensive result analysis has been made. The result analysis shows the effectiveness and significant improvement of the proposed control technique.
  • Optimized dual active bridge Bi-directional DC-DC converter for UPS application

    Narasimharaju B.L., Prahlad V.V., Reddy U.R., Vijay Babu K., Srinivasan P.

    Conference paper, 2014 IEEE International Conference on Power Electronics, Drives and Energy Systems, PEDES 2014, 2014, DOI Link

    View abstract ⏷

    With the growing emphasis on smaller compact and efficient power system there is increasing interest in the possibility of using Bi-directional converters especially in DC based power applications. Having the capability of bilateral power flow, that provides the functionality of two uni-directional converters in single converter unit; Bidirectional converters have the increased industrial applications; demand optimized study of topologies and feasibility, critical feature study for the considered application. This document suggests an optimized implementation of Bidirectional DC-DC converter to fit the present day UPS application. Key issues like compact design, utilisation of transformer core, optimised topology for low power (2.5kW) applications were discussed.
Contact Details

ramanjaneya.r@srmap.edu.in

Scholars

Doctoral Scholars

  • Challa Siva Koti Reddy
  • Ms Dasari Sai Ram Surya Lakshmi Avanthika
  • Mr Kamireddy Ravivarma
  • Ms Maya Vijayan