Browsing by Author "Nagendrappa, H."

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A fixed frequency ZVS integrated boost dual three-phase bridge DC-DC LCL-type series resonant converter for large power applications
(Institute of Electrical and Electronics Engineers Inc., 2017) Nagendrappa, H.; Bhat, A.K.S.
The design of a converter as an example of a high power (>10 kW), fixed frequency controlled three-phase DC-DC LCL-type series resonant converter (SRC) with integrated boost function is described. The specifications of the converter are chosen to match the rating of a linear generator (LG) used in wave energy generation application. The performance of the designed converter has been verified by using PSIM simulation software. The zero-voltage-switching (ZVS) of all the switches is accomplished by designing the converter to operate in the lagging pf mode for a wide input voltage and load variations. Theoretical and simulation results have been compared and presented in the form of a table. Power loss break-down analysis of the designed converter has been done and the summary of results is presented. Â© 2017 IEEE.
A Fixed-Frequency ZVS Integrated Boost Dual Three-Phase Bridge DC-DC LCL-Type Series Resonant Converter
(Institute of Electrical and Electronics Engineers Inc., 2018) Nagendrappa, H.; Bhat, A.K.S.
A new fixed-frequency controlled three-phase dc-dc LCL-type series resonant converter with integrated boost function is proposed for medium to large power applications with wide input voltage variation that is typical of alternate energy sources. The converter includes a dual three-phase LCL-type resonant bridge inverter modules connected in parallel, thus significantly reducing the component stresses when subjected to medium to large power applications. The fixed-frequency control of the output power is achieved by phase shifting the gating signals of one module with respect to the other, while the rectified voltage at the secondary windings of a three-phase high-frequency transformer connected between the two modules is added to the input voltage to boost the supply voltage to the modules. The zero-voltage-switching of all the switches is accomplished by designing the converter to operate in the lagging PF mode for wide variations in the input voltage and the load. Detailed modeling of the three-phase boost section is done and the steady-state analysis of the proposed converter for three-phase LCL-type dc-dc converter modules using complex ac circuit analysis method is presented. For illustration purpose, a dc-dc converter of 600 W is designed, and its performance is verified using PSIM simulations. An experimental model of the converter is built in the laboratory to verify its performance for wide variations in input voltage and load changes. © 2017 IEEE.
A Novel Cubic Boost Converter With Continuous Source Current for PV Applications
(Institute of Electrical and Electronics Engineers Inc., 2024) Srinivas, B.; P, P.; Nagendrappa, H.; Balasubramanian, B.
A converter with high voltage gain is generally necessary for interfacing the photovoltaic (PV) systems with grid. However, more semiconductor components are needed to obtain a higher voltage gain, which results in increased losses. This brief proposes a novel non-isolated cubic boost (NNICB) DC-DC converter for high-voltage PV applications with a wide voltage gain at a lower duty ratio. Compared to traditional high-gain DC-DC converter, the NNICB converter counters the drawbacks of increased component count and high voltage stress. The NNICB DC-DC converter has a continuous source current for PV applications with low-voltage stress across the diodes and switches. A detailed steady-state analysis of the NNICB topology is carried out for the ideal and non-ideal models, and their corresponding voltage gain equations are computed. Furthermore, the analysis is performed using MATLAB/Simulink and is validated using a 230 W laboratory prototype. The experimental results show that the efficiency of the proposed NNICB topology is 94.42% with a voltage gain of 10.5 at 45% duty ratio. This proves the superior performance of the proposed novel converter in comparison with the existing topologies. © 2004-2012 IEEE.
A Novel Dual Transformer Triple Active Bridge to Interface Renewable Energy Storage and Load
(Institute of Electrical and Electronics Engineers Inc., 2023) Adarsh, S.; Nagendrappa, H.
A novel topology of dual transformer triple active bridge is proposed for interfacing renewable energy storage system with the load. This topology uses series connection of dual transformers to reduce the circulating current and the number of semiconductor devices. Phase shift and duty ratio control are used to control the bidirectional power flow and regulate the load voltage. Duty ratio control also results in zero-voltage switching (ZVS) of all the converter switches for the entire input voltage and load range. The converter is designed to reduce switch stress. The simulation of a 1 kW converter is done to verify its performance for a variable load, supply voltage, and bi-directional power flow. From the results, it is found that the topology regulates the output voltage for variations both in supply voltage and load. In the duty ratio controlled topology, all switches turn on with ZVS for all operating cases. Â© 2023 IEEE.
Analysis and design of a high frequency isolated full bridge CLL resonant DC-DC converter for renewable energy applications
(2018) Patil, U.; Nagendrappa, H.
In this paper, a new PWM gating scheme is proposed for fixed frequency full-bridge DC-DC CLL resonant converter with capacitive output filter. An approximate complex ac circuit approach is used for the steady state analysis of the converter. The optimum design of the converter is described with the help of design curves for a sample converter of rating 200 W, 40-80 V DC input and output DC voltage of 200 V. By applying the proposed gating scheme, higher conversion efficiency is obtained due to zero-voltage-switching of the converter switches for wide variations in input voltage and the load. PSIM simulations are performed to verify theoretical predictions about the performance of the converter for variations in load and input voltage. The theoretical and simulation results are given and discussed. � 2018 IEEE.
Analysis and design of a high frequency isolated full bridge CLL resonant DC-DC converter for renewable energy applications
(Institute of Electrical and Electronics Engineers Inc., 2018) Patil, U.; Nagendrappa, H.
In this paper, a new PWM gating scheme is proposed for fixed frequency full-bridge DC-DC CLL resonant converter with capacitive output filter. An approximate complex ac circuit approach is used for the steady state analysis of the converter. The optimum design of the converter is described with the help of design curves for a sample converter of rating 200 W, 40-80 V DC input and output DC voltage of 200 V. By applying the proposed gating scheme, higher conversion efficiency is obtained due to zero-voltage-switching of the converter switches for wide variations in input voltage and the load. PSIM simulations are performed to verify theoretical predictions about the performance of the converter for variations in load and input voltage. The theoretical and simulation results are given and discussed. Â© 2018 IEEE.
Analysis and Design of a Three Phase Interleaved CLL Resonant Converter with Fixed Frequency Modified PWM Control
(Institute of Electrical and Electronics Engineers Inc., 2021) Patil, U.; Nagendrappa, H.
A Three-phase interleaved CLL resonant DC-DC converter with fixed frequency modified PWM gating pattern is presented in this paper. The main benefit of the interleaving technique of the converter is to achieve higher power level, while reducing the size of filters due to lower ripples. Three identical single-phase full bridge inverter circuits with CLL resonant tank are allied in parallel on the primary of the high-frequency (HF) transformer. The operating modes of the converter for different intervals are explained with the aid of key operating waveforms. The fundamental harmonic approximation (FHA) approach is used to carry out the steady-state analysis of the converter. A 600W converter is designed and the design method is explained. PSIM simulations are done to substantiate the calculated predictions of the converter for distinct operating conditions. Â© 2021 IEEE.
Autonomous microgrid based parallel inverters using droop controller for improved power sharing
(Institute of Advanced Engineering and Science info@iaesjournal.com, 2020) Siddaraj, U.; Yaragatti, U.R.; Nagendrappa, H.; Jhunjhunwala, V.K.
The existing microgrid has become a challenge to the sustainable energy source to provide a better quality of power to the consumer. To build a reliable and efficient microgrid, designing a droop controller for the microgrid is of utmost importance. In this paper, multiple voltage source inverters connected in parallel using an active power-frequency/reactive power-voltage droop scheme. The proposed method connected to two distributed generators local controllers, where each unit consists of a droop controller with an inner voltage-current controller and a virtual droop controller. By adding this controller to the microgrid reliability and load adaptability of an islanded system can be improved. This concept applied without any real-time communication to the microgrid. Thus, simulated using MATLAB/Simulink, the obtained results prove the effectiveness of the autonomous operation's microgrid model. © 2020, Institute of Advanced Engineering and Science. All rights reserved.
Autonomous Microgrid Using New Perspective on Droop Control in AC Microgrid
(Springer Science and Business Media Deutschland GmbH, 2024) Siddaraj, U.; Yaragatti, U.R.; Nagendrappa, H.
Providing higher quality power to consumers through the existent microgrid is now a problem for the renewable energy source. Designing a droop controller for the microgrid is a necessity to construct a dependable and effective microgrid. In this paper, a Pâ€“F/Qâ€“V droop method is used to connect several VSIs in parallel. Their parallels and differences are amply discussed in this study. A frequency droop control method and a virtual impedance approach are combined in the suggested method, which is coupled to two distributed generation (DG) local controllers and has each unit having a droop control and a voltage-current controller. An islanded system's load flexibility and microgrid reliability can both be enhanced by adding this controller. The microgrid was subjected to this idea without any real-time communication. Simulink/MATLAB was used to simulate this. The results obtained show that the microgrid (MG) model is effective in autonomous operation. Â© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.
Challenges in Developing Hardware-In-Loop Model of Cage Induction Motor with Eccentricity Fault
(2018) Ilamparithi, T.; Rangachar, B.; Rangineedi, T.; Nagendrappa, H.
In this paper, an attempt is made to develop a MATLAB based Hardware-In-Loop compatible model of a three phase cage induction motor with a provision to accommodate eccentricity fault. The major benefits of the attempted work include compatibility with commercially available real-time simulators, facilitation of testing motor control units of electric vehicles when the motor is subjected to eccentricity fault, and ability to simulate in real-time varying severities of eccentricity fault. Modeling of the eccentricity fault is made by using the widely adopted modified winding function approach. Real-time simulation of the developed model is attempted by building a MATLAB model that utilizes pre-computed inductances for real-time execution. Finally, the major challenges encountered in this attempt are presented and discussed to pave way for further research. � 2018 IEEE.
Challenges in Developing Hardware-In-Loop Model of Cage Induction Motor with Eccentricity Fault
(IEEE Computer Society help@computer.org, 2018) Ilamparithi, T.; Rangachar, B.; Rangineedi, T.; Nagendrappa, H.
In this paper, an attempt is made to develop a MATLAB based Hardware-In-Loop compatible model of a three phase cage induction motor with a provision to accommodate eccentricity fault. The major benefits of the attempted work include compatibility with commercially available real-time simulators, facilitation of testing motor control units of electric vehicles when the motor is subjected to eccentricity fault, and ability to simulate in real-time varying severities of eccentricity fault. Modeling of the eccentricity fault is made by using the widely adopted modified winding function approach. Real-time simulation of the developed model is attempted by building a MATLAB model that utilizes pre-computed inductances for real-time execution. Finally, the major challenges encountered in this attempt are presented and discussed to pave way for further research. Â© 2018 IEEE.
Comparative Analysis of Symmetrical and Asymmetrical Phase Shift Control Strategy for Resonant Wireless Inductive Charging System
(Institute of Electrical and Electronics Engineers Inc., 2021) Vinod, M.; Kishan, D.; Nagendrappa, H.; Dastagiri Reddy, B.D.
This paper describes the operation and performance analysis of series/series resonant wireless inductive charging system with symmetrical phase shift (SPS) and asymmetrical phase shift (APS) control strategies. The H-bridge inverter switches of the resonant wireless inductive charging system (RWICS) are designed to operate with zero voltage switching. The comparison of the SPS, APS switching strategies are discussed in regulation of output voltage for different loading conditions and step change in the reference voltages. It is found that the system efficiency is higher with APS control strategy. Also, the variation in pulse-width angle required for controlling the output voltage is small for various loading conditions in APS compared to the SPS. The MATLAB/Simulink Simulation results confirmed that APS control strategy provides superior performance than SPS control for different loading and different output desired conditions. Â© 2021 IEEE.
Comparative Study on Efficiency and Output Voltage Regulation in Dual-Active Bridge Converter with SPS and TPS Modulation under Input Voltage Variations
(Institute of Electrical and Electronics Engineers Inc., 2024) Ur Rehman, M.B.; Ilamparithi, T.; Nagendrappa, H.
The comprehensive performance characteristics of two prominent modulation techniques on Dual-Active Bridge (DAB) converter: Single Phase Shift (SPS) and Triple Phase Shift (TPS) is presented in this paper. The DAB converter topology is a promising architecture for its high-efficiency, bidirectional power conversion, galvanic isolation and flexible gating schemes. The primary objective is to evaluate the effectiveness of modulation techniques on output voltage regulation under varying input voltage conditions. Phase displacement patterns and their correlation with the varying input voltage are illustrated graphically along with the detailed results. A comprehensive design analysis is developed, followed by the detailed simulation results is showcased for a 1 kW converter in boost mode of operation. This study highlights the insights for the selection and optimization of modulation strategies for DAB converter in applications demanding precise output voltage regulation and high efficiency. Â© 2024 IEEE.
Comparison of Phase-Shift and Modified Gating Schemes on Working of DC-DC LCL-T Resonant Power Converter
(Institute of Electrical and Electronics Engineers Inc., 2021) Reddy, V.B.; Nagendrappa, H.
This brief discusses the operation and performance comparison of LCL-T DC-DC resonant power converter when controlled with fixed-frequency phase-shifted gating (PSG) and modified-gating signals (MGS) schemes. The converter is designed to operate in lagging power factor mode to accomplish zero-voltage switching (ZVS) of the inverter switches. The operating principle of the converter with the two proposed gating schemes is explained. A brief steady-state analysis of the converter using Fourier series approach is presented. The choice between PSG and MGS schemes is made by comparing the performance of the converter. It is found that both the gating schemes are effective in regulating the output voltage for variable input voltage and loading conditions. However, the efficiency of the converter is found to be higher with MGS due to the fact that only one switch loses ZVS as compared to two with the PSG when operated with maximum input voltage. Also, the variation in pulse-width angle (?) required to regulate the output voltage is small in MGS as compared to that with PSG. A 300 W experimental prototype of the converter has been built and tested to verify the theoretical results. It is experimentally confirmed that the MGS control gives the better performance than the PSG control for different input voltage and loading conditions. © 2004-2012 IEEE.
Design of Spiral Square Inductive Power Pads with Misalignment for Wireless Power Transfer System
(Institute of Electrical and Electronics Engineers Inc., 2021) Vinod, M.; Kishan, D.; Nagendrappa, H.; Kannan, R.
Wireless power transfer (WPT) can find the potential applications reaching from power transfer to low power appliances to high power electric vehicle battery charging and industrial systems applications. Inductive power pads are the key components for magnetic induction based WPT systems. Hence, this paper labels the analysis of magnetic coupling characteristics of spiral square inductive pads with various misalignments. In this process the inductive power pads are designed in FEM simulation. The modelling approach is presented to calculate the coupling coefficient, self and mutual inductance of spiral square inductive pads of WPT system and also presented the power and efficiency analysis of the system. Â© 2021 IEEE.
Fixed frequency control of LCL-T resonant power converter with capacitive output filter
(2018) Reddy, G.V.B.; Nagendrappa, H.
In this paper, a fixed-frequency phase shift control is proposed for a 1-phase series-parallel LCL-T resonant converter. Zero-voltage switching (ZVS) of the inverter switches for wide variations in input voltage and load is achieved by designing the converter to operate in above resonance mode. Steady state approximate AC circuit analysis method is used to analyze the converter with fixed-frequency phase shift control. LCL-T converter offers a built-in protection against short-circuiting of the load. LCL-T converter with fixed-frequency control requires a very small change in phase shift to regulate the output voltage for wide variations in input voltage and load. Due to ZVS for the entire input voltage and load variations, the operating efficiency of the converter is high. A 300 W, DC-DC, LCL-T resonant converter is designed for solar energy generation applications. The performance of the converter with the proposed fixed-frequency phase shift control is studied with PSIM simulations. The theoretical and simulation results are compared and presented. � 2017 IEEE.
Fixed frequency control of LCL-T resonant power converter with capacitive output filter
(Institute of Electrical and Electronics Engineers Inc., 2017) Reddy, G.V.B.; Nagendrappa, H.
In this paper, a fixed-frequency phase shift control is proposed for a 1-phase series-parallel LCL-T resonant converter. Zero-voltage switching (ZVS) of the inverter switches for wide variations in input voltage and load is achieved by designing the converter to operate in above resonance mode. Steady state approximate AC circuit analysis method is used to analyze the converter with fixed-frequency phase shift control. LCL-T converter offers a built-in protection against short-circuiting of the load. LCL-T converter with fixed-frequency control requires a very small change in phase shift to regulate the output voltage for wide variations in input voltage and load. Due to ZVS for the entire input voltage and load variations, the operating efficiency of the converter is high. A 300 W, DC-DC, LCL-T resonant converter is designed for solar energy generation applications. The performance of the converter with the proposed fixed-frequency phase shift control is studied with PSIM simulations. The theoretical and simulation results are compared and presented. Â© 2017 IEEE.
Four-Phase Interleaved Bidirectional DC-DC Converter for Battery Energy Storage System
(Institute of Electrical and Electronics Engineers Inc., 2023) Kumar, V.; Nagendrappa, H.
This paper presents the operation of a DC-DC converter for bidirectional power transfer with battery energy storage system. The converter topology under study resolves the existing disadvantages of conventional buck - boost bidirectional converter and provides benefits in terms of reduced size with higher efficiency and lower input source ripple current. The performance of non-isolated 4-phase interleaved buck-boost bidirectional converter has been studied using MATLAB simulations. In order to get a better insight, this paper proposes a control method that takes the interaction of 4phase currents into account. In boost mode operation, battery is getting discharged while it maintains the DC bus voltage. In buck mode operation, battery is getting charged at constant current. The design of non-isolated four-phase interleaved bidirectional converter of 150 kW with simulation results are presented to validate the design and performance of the converter. Â© 2023 IEEE.
Fuzzy Logic Based Totem pole- PFC Converter
(Institute of Electrical and Electronics Engineers Inc., 2023) Khaza, M.F.; Thakur, S.; Nagendrappa, H.; Balasubramanian, B.
Power quality is always a major threat to grid-connected systems. Different topologies can be used in EV chargers. However, due to several limitations in the active Power Factor Correction (PFC) and proportional-integral (PI) based PFC has led to exploring advanced schemes. This paper presents novelty by introducing fuzzy logic with totem pole power factor correction. An attempt has been made to use this PFC for Electric Vehicle (EV) chargers. Totem pole topology offers high efficiency, low conduction loss, and high speed. The proposed scheme uses two loops with an inner loop having a current error amplifier to control the input line current and the outer loop involving fuzzy logic controller (FLC), to control the output voltage. This makes the input current be shaped in phase with input voltage accordingly with reference parameters. The proposed system is verified using extensive simulations in MATLAB/Simulink and the results are compared with PI-based PFC. Results show that the proposed scheme improves the performance significantly with total harmonic distortion (THD) limited to IEEE standards limit having nearly unity power factor. Â© 2023 IEEE.
Modified Gating Signal Controlled High-Frequency Transformer Isolated LCL-T Type DC-DC Resonant Power Converter
(2018) Vijaya, Bhaskar, R.G.; Nagendrappa, H.
In this paper, a LCL-T type of resonant power converter using modified gating signals is proposed for PV applications. The fixed-frequency modified gating is adopted to process and control the power flow in the circuit. The converter is designed to operate in lagging pf mode to ensure zero-voltage switching (ZVS) of the inverter switches. Fourier series method is used to analyze the converter in steady-state. The main advantage of LCL-T converter is that it provides protection against load short circuit. It is shown that a small change in pulse width is required to regulate the output voltage for variations in input voltage and load. A 300 W converter is designed and its performance is studied using PSIM simulations. Power loss breakdown analysis is performed. � 2018 IEEE.