Browsing by Author "Kalpana, R."

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A 36-Pulse AC-DC Converter with DC Side Tapped Interphase Bridge Rectifier for Power Quality Improvement
(2018) Saravana, Prakash, P.; Kalpana, R.; Chethana, K.S.; Singh, B.
This paper presents a circuit configuration to reduce the harmonic contents at the AC mains of a 12-pulse zigzag configured autotransformer based DBR. The proposed circuit configuration employs a tapped interphase bridge rectifier at the DC side of 12-pulse DBR that results in higher pulses in the supply current. Thus, reducing the harmonic content and thereby improving the power quality of the system. Since the autotransformer employed is zigzag configured, the need for ZSBT is eliminated. Moreover, the proposed circuit configuration at the DC side shapes the supply current near to a sine wave. Further, the proposed configuration is analyzed, simulated in MATLAB Simulink and the simulation results are presented, which confirms the improvement in power quality parameters in the input AC line current. Further, the viability of the proposed configuration is verified by experimental results which confirm the suitability of the proposed configuration in AC-DC applications. � 2018 IEEE.
A 20-Pulse Asymmetric Multiphase Staggering Autoconfigured Transformer for Power Quality Improvement
(Institute of Electrical and Electronics Engineers Inc., 2018) P, P.; Kalpana, R.; Singh, B.; Bhuvaneswari, G.
This letter presents a 20-pulse multiphase staggering autoconfigured transformer (MSAT) for power quality improvement in medium and high power applications. The proposed autoconfigured transformer is a combination of delta and zig-zag transformers. Contrary to the prior art multipulse autoconnected transformers, magnetic rating of the proposed configuration is only 40% of the load rating in addition to improved power quality indices. Moreover, the creation of a neutral point ascribed to inbuilt zig-zag windings supplements as one of the remarkable advantages of the proposed MSAT. Therefore, with this suggested configuration, the performance of zig-zag transformer is accomplished within the autoconfigured transformer. A detailed comparison of the proposed MSAT configuration with that of other multipulse autoconnected transformers in terms of magnetic rating and power quality indices are presented. Further, the feasibility and operability of the proposed MSAT are verified and validated through experimental tests on the laboratory prototype. The test results so obtained complies with the IEEE-519 and IEC 61000-3-2 standards on power quality requirements. © 2017 IEEE.
A 36-Pulse AC-DC Converter with DC Side Tapped Interphase Bridge Rectifier for Power Quality Improvement
(Institute of Electrical and Electronics Engineers Inc., 2018) P, P.S.; Kalpana, R.; Chethana, K.S.; Singh, B.
This paper presents a circuit configuration to reduce the harmonic contents at the AC mains of a 12-pulse zigzag configured autotransformer based DBR. The proposed circuit configuration employs a tapped interphase bridge rectifier at the DC side of 12-pulse DBR that results in higher pulses in the supply current. Thus, reducing the harmonic content and thereby improving the power quality of the system. Since the autotransformer employed is zigzag configured, the need for ZSBT is eliminated. Moreover, the proposed circuit configuration at the DC side shapes the supply current near to a sine wave. Further, the proposed configuration is analyzed, simulated in MATLAB Simulink and the simulation results are presented, which confirms the improvement in power quality parameters in the input AC line current. Further, the viability of the proposed configuration is verified by experimental results which confirm the suitability of the proposed configuration in AC-DC applications. Â© 2018 IEEE.
A 36-Pulse AC-DC Converter with DC-Side Tapped Interphase Bridge Rectifier for Power Quality Improvement
(Institute of Electrical and Electronics Engineers Inc., 2021) P, P.P.; Kalpana, R.; Chethana, K.S.; Singh, B.
This article presents a circuit configuration to reduce the harmonic contents at the ac mains of a 12-pulse zigzag configured autotransformer-based diode bridge rectifier (DBR). The proposed circuit configuration employs a tapped interphase bridge rectifier at the dc side of 12-pulse DBR that results in higher pulses in the supply current, thus reducing the harmonic content and, thereby, improving the power quality of the system. Since the autotransformer employed is zigzag configured, the need for zero-sequence blocking transformer is eliminated. Moreover, the proposed circuit configuration at the dc side shapes the supply current near to a sine wave. Further, the proposed configuration is analyzed, simulated in MATLAB/Simulink, and the simulation results are presented, which confirms the improvement in power quality parameters in the input ac line current. Furthermore, the viability of the proposed configuration is verified by the experimental results that confirm the suitability of the proposed configuration in ac-dc applications. © 1972-2012 IEEE.
A Global Maximum Power Point Tracking Technique of Partially Shaded Photovoltaic Systems for Constant Voltage Applications
(Institute of Electrical and Electronics Engineers Inc., 2019) Goud, J.S.; Kalpana, R.; Singh, B.; Kumar, S.
The P-V characteristics of photovoltaic (PV) array exhibit several maximum power points (MPP) during non-uniform insolation (i.e., during partial shading) conditions; there exists only one global MPP (GMPP), whereas others are referred to local MPP. This paper presents a technique to track the GMPP for the constant voltage or battery loads during partial shading conditions using a single sensor connected to the battery terminals. The proposed method introduces fast and efficient scanning based method, i.e., scanning Ibatt-D curve of power electronic interface at selective duty cycles to recognize the kind of the solar shading pattern (i.e., kind of P-V curve) on PV array and to find the GMPP neighborhood. Moreover, the proposed method overcomes the drawbacks of existing methods such as low convergence speed, increased number of sensors, and heavy computational complexity. The proposed GMPPT method is simulated in MATLAB/Simulink and validated through test results on a prototype for various non-uniform insolation conditions. The results have shown that this paper tracks the GMPP with best tracking efficiency and fast tracking speed. Further, the proposed method is compared with two P-V curve scanning based GMPPT methods and one global optimization based artificial bee colony method. © 2018 IEEE.
A Hybrid Global Maximum Power Point Tracking Technique with Fast Convergence Speed for Partial-Shaded PV Systems
(Institute of Electrical and Electronics Engineers Inc., 2018) Goud, J.S.; Kalpana, R.; Singh, B.
Photovoltaic (PV) systems exhibit multiple local and one global maximum power points (MPPs) in their P -V and I-V curves during partial shading conditions (PSC). Thus, to improve the efficiency of the system, a global maximum power point tracking (GMPPT) algorithm is necessary. This paper presents a hybrid GMPPT algorithm for constant voltage load applications using a single current sensor. The proposed method combines single current sensor hill climbing (SSHC) and artificial bee colony (ABC) algorithms to track the GMPP. The SSHC algorithm detects the event of PSC and tracks the MPP during uniform insolation conditions. The output current of the power electronic interface is measured effectively at selective duty cycles to identify the type of P-V curve pattern and, thus, initiate either SSHC or ABC. The search space for the ABC algorithm is reduced in the proposed technique to improve the convergence speed. The proposed GMPPT technique is simulated in MATLAB and validated through experimental prototypes for various PSCs. The proposed algorithm tracks the GMPP with excellent efficiency and fast speed. © 1972-2012 IEEE.
A Modified Reaching Law Based Sliding Mode Controller with an Antidisturbance Approach for Speed Control of PMSM System
(Institute of Electrical and Electronics Engineers Inc., 2023) Chiliveri, V.R.; Kalpana, R.; Kishan, D.
This paper develops a robust non-linear control system that employs the sliding mode control (SMC) technique to enhance the speed regulation performance of the permanent-magnet-synchronous-motor (PMSM) in the existence of parameter mismatch and external load disturbances. Initially, the modified reaching law-based SMC (MRL-SMC) method is proposed. This MRL-SMC incorporates an exponential sliding surface function and system tracking error to enable adaptive changes in the reaching law during two distinct SMC phases. As a result, this method mitigates the inherent chattering generated in the control input and accelerates the reaching speed of the system states towards the sliding manifold. Moreover, due to high switching gain requirement to suppress the effect of lumped disturbances give rise to large chattering. Therefore, an antidisturbance approach is proposed in composite to MRL-SMC. This method consists of a finite-time disturbance observer for estimating the lumped disturbance and initiate a feedforward compensation of the estimated disturbance to the MRL-SMC. Additionally, the simulation results demonstrate that the proposed speed control technique is more effective compared to conventional SMC. Â© 2023 IEEE.
A Modularized Two-Stage Active Cell Balancing Circuit for Series Connected Li-Ion Battery Packs
(Institute of Electrical and Electronics Engineers Inc., 2022) Manjunath, K.; Kalpana, R.
This paper addresses a modularized two-stage active cell balancing topology based on an improved buck-boost converter for a series connected Lithium-ion battery string. The proposed topology has a modular structure, each module consisting of three cells, two inductors, and four MOSFET switches. This technique provides module-to-module balancing in the first stage. Moreover, it can simultaneously target and balance two cells in a module in the second stage. Thus, significantly reduces the cell balancing time and increases the system performance with minimal components. The proposed topology has been theoretically analyzed and experimentally verified with a laboratory prototype. The proposed modularization technique is verified experimentally with two modules tested together in a battery string. Â© 2022 IEEE.
A Modularized Two-Stage Active Cell Balancing Topology With Reduced Balancing Time for Series Connected Li-Ion Battery String
(Institute of Electrical and Electronics Engineers Inc., 2025) Manjunath, K.; Kalpana, R.; Singh, B.
This paper introduces a modularized two-stage active cell balancing topology utilizing an improved buck-boost converter for a series-connected lithium-ion battery string. The proposed topology adopts a modular structure where each module comprises three cells, two inductors, and four MOSFET switches. The voltage monitoring circuit controls the switches to ensure each cell has same voltage by transferring charge from a source cell to target cell. This approach enables module-to-module balancing through a module equalizer while simultaneously targeting two cells within a module through a cell equalizer. Using modularization technique in the proposed topology, the balancing time is reduced significantly compared to cell equalization circuit. Moreover, using a combination of cell and module balancing, the balancing time is reduced effectively compared with performing cell balancing only under dynamic charging/discharging conditions. This methodology substantially reduces cell equalization time and enhances system performance with minimal components. Proposed topology is verified theoretically and experimentally with a five-module battery string under static and dynamic conditions. © 1972-2012 IEEE.
A New Three Port Converter with Power Flow Management Control for Solar PV fed Telecom Load
(Institute of Electrical and Electronics Engineers Inc., 2020) Sheeja, V.; Kalpana, R.
Multiport converters are reported in the literature for integrating multiple power sources, primarily renewable energy sources along with energy storage systems. The use of multiport converters decreases power conversion stages and hence increased efficiency. A three port converter is presented in this paper for solar PV fed telecom load. The control of the three port converter for the power flow management is also discussed. A solar PV array, battery energy storage and the telecom DC load are connected at the three ports of the converter. The performance of the converter along with the power flow management control is validated with detailed simulation studies using MATLAB with its SimPower System Blockset. Â© 2020 IEEE.
A non-isolated bidirectional high gain integrated multiport converter for grid tied solar PV fed telecom load
(John Wiley and Sons Inc, 2023) Sheeja, V.; Kalpana, R.; Singh, B.; Subramaniam, U.; Muhibbullah, M.
A multiport converter (MPC) with a non-isolated high gain bidirectional port is proposed for the grid integration of solar photovoltaic array (SPA) fed telecommunication load. The SPA along with a battery energy storage (BES) meets the power demand of the telecom DC load and the excess/deficit power is exchanged with AC grid. The MPC feeds the DC link of a voltage source converter for bidirectional operation with the AC grid. The small signal analysis of the converter shows that its operation is stable. The SPA, BES, and telecommunication load are rated for lower voltages, consecutively reducing the complexity with series-connected SPA. The proposed MPC possesses the merits of high voltage gain, reduced inductor size, and reduced number of components. Moreover, a power flow management algorithm is devised for the proposed converter that regulates the DC voltage at the telecom load and ensures smooth power flow control among various ports. The MPC is able to operate at various modes by controlling the ports independently. The converter performance during steady state and dynamic operating conditions under various modes are analyzed with detailed simulation studies. An experimental prototype is developed and test results are demonstrated to prove the viability of the designed converter. © 2022 The Authors. IET Power Electronics published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.
A Non-Isolated Buck-Boost DC-DC Converter for On-Board Electric Vehicle Powertrain
(Institute of Electrical and Electronics Engineers Inc., 2023) Vinusha, B.; Kalpana, R.; Kishan, D.
In this paper, a non-isolated buck-boost DC-DC converter for on-board electric vehicle powertrain is proposed. It has a universal-input voltage capability for the requirement of power factor correction in electric vehicles. It can be operated in buck, boost, or pass-through modes to optimize performance depending on the operating conditions. It has advantages of lower switch voltage stresses, reduced size of the magnetics and lower inductor conduction losses in comparison to single-switch buck-boost converters or other two-switch buck-boost converters. The operation of the converter in buck and boost modes is discussed in detail, followed by necessary mathematical modelling. To validate the effectiveness of proposed converter, simulation studies are carried-out with the help of MATLAB-Simulink. Â© 2023 IEEE.
A Nonisolated High Gain Bidirectional DC–DC Converter With Reduced Switch Count: Analysis and Implementation
(Institute of Electrical and Electronics Engineers Inc., 2025) VSheeja, S.; Kalpana, R.; Singh, B.
This article investigates a bidirectional dc–dc converter having a very high voltage gain for grid integration of a microgrid supported by renewable power sources. The proposed converter interfaces the low-voltage solar PV and battery energy storage systems with a high-voltage system. Because of its large voltage gain both in forward and reverse operating modes, the proposed converter can be used at lower and moderate duty ratios. In comparison to previously reported topologies of a similar nature, this converter can provide better performance with fewer switches and passive components, resulting in better efficiency. The input current's ripple is observed to be lowered as a result of the parallel operation of inductors. The converter stability is investigated using state space modeling and small signal analysis. The laboratory hardware prototype confirms the suggested converter's effectiveness for bidirectional operation, and the outcomes are in line with theoretical studies. © 2020 IEEE.
A Power Quality Enhanced Push-Pull Converter-Based Two-Stage Onboard Charger for Electric Vehicle Applications
(Institute of Electrical and Electronics Engineers Inc., 2025) Suprabha Padiyar, U.S.; Kalpana, R.
This paper presents an efficient two-stage onboard charger (OBC) using AC-DC converters with improved power quality for electric vehicle (EV) applications. The first stage comprises a diode bridge rectifier (DBR) without an input AC filter and a front-end boost converter (FBC) as a power factor correction (PFC) circuit, stabilizing the output voltage for efficient power transfer. The boost inductor current control is facilitated using a phase-locked loop to achieve input current wave shaping. This FBC drives the second-stage back-end push-pull converter (BPPC) operating in buck mode to ensure the battery is charging in constant current (CC) control mode. The push-pull converter demands its inductor current to be continuous due to the CC mode of battery charging. A detailed analysis of the power converters is conducted through simulations performed using the MathWorks SIMULINK software. Furthermore, a scaled-down hardware prototype has been developed, utilizing a dSPACE 1202 controller, to evaluate the effectiveness of the charger for a 48 V, 100 Ah battery. The test results demonstrate satisfactory performance and compliance with the IEC 61000-3-2 standard. This design effectively maintains input AC power quality during battery charging, highlighting its potential for enhancing EV charging infrastructure. © 2025 The Authors.
A Reduced Switch Count Switched Capacitor Based High Voltage Gain Bidirectional DC-DC Converter for Grid Integration of BTS
(Institute of Electrical and Electronics Engineers Inc., 2020) Sheeja, V.; Kalpana, R.; Singh, B.
A high voltage gain bidirectional DC-DC converter with reduced switch count is presented in this work. Renewable energy sources such as solar PV array, that are available at low DC voltage, is being used for supporting the DC load of a base transceiver station along with battery energy storage. Hence, the low voltage DC grid system requires a bidirectional DC-DC converter for the bidirectional power flow with the AC grid. This converter has a high gain compared to other existing topologies with reduced active switch count. The performance of it is validated with detailed simulations and a hardware prototype. Moreover, the performance of the system is analyzed and studied for step-up and step-down operations with a solar PV array, BES and a load connected to DC grid. Â© 2020 IEEE.
A Study on Methods For Estimation And Modelling of Piezo-Electric Load and Matching Circuit
(Institute of Electrical and Electronics Engineers Inc., 2023) Tiwari, K.; Venkatachalam, S.; Vamshi, A.C.; Parthiban, P.; Kalpana, R.
A piezoelectric load has complex impedance characteristics and exhibits different impedance at different frequencies. This property of the material makes the mathematical modelling of it a complex procedure that should be approached meticulously. To estimate piezoelectric transducer impedance characteristics, which may be represented using an electrical equivalent circuit. Two different modelling approaches are compared with the original load response. The model, having more proximity with the generally original circuit response for the most part, is taken for study and further optimized with the help of numerical iterative methods so that a near-perfect model of the load can be used. The model is refined and improved using numerical iterative methods to accurately represent the load's behavior using the Levenberg-Marquardt and Trust-Region-Reflective numerical algorithms for this optimization. Additionally, designing a matching circuit for the piezoelectric load, focusing on maximizing power transfer and filter applications, is discussed. Â© 2023 IEEE.
A Three-Phase Isolated Multilevel AC-DC Converter for Dual Electric Vehicle Battery Charging
(Institute of Electrical and Electronics Engineers Inc., 2025) Vinusha, B.; Kalpana, R.; Kishan, D.
In this paper, a two-stage electric vehicle (EV) architecture of an AC-DC converter is proposed for charging two batteries at a time. It consists of a three-phase multilevel boost PFC converter followed by a bidirectional dual-output DC-DC converter. Also, the DC-DC converter has a Zero voltage switching (ZVS) and isolated outputs. The two stages function independently, allowing the AC-DC stage to operate in continuous conduction mode (CCM) without affecting the duty cycle variation of the DC-DC stage. A suitable control technique is also proposed to improve total harmonic distortion (THD) and power factor, equal power sharing of two batteries. A detailed operating analysis of the proposed dual battery charger is discussed. The effectiveness of the proposed charger is validated by extensive test of laboratory prototype. © 1972-2012 IEEE.
A Two Switch Multiport Non-Isolated DC-DC Converter for On-Board EV Charging Application
(Institute of Electrical and Electronics Engineers Inc., 2024) Vinusha, B.; Kishan, D.; Kalpana, R.
This paper proposes multiport DC-DC converter for on-board charger (OBC) EV applications with simultaneous charging of high voltage (HV) battery and low voltage (LV) battery. The evolution of this converter involves replacing the switch found in a conventional step-up converter with a pair of series-connected switches. This arrangement allows for an additional switch node that generates a LV output. the proposed converter has benefits of high voltage gain for HV side, continuous input current, a reduced switching count, regulation of two battery voltages with two switches. Moreover, the inherent shoot-through protection enhances the converter's reliability. The proposed converter exhibits same working principle as that of conventional boost and buck converters. Consequently, the control system methodology remains consistent with that of separate converters, ensuring precise regulation of each output. The working principle, design analysis is discussed. To validate the theoretical analysis, detailed simulation results are presented. Â© 2024 IEEE.
A Two-Stage Module Based Cell-to-Cell Active Balancing Circuit for Series Connected Lithium-Ion Battery Packs
(Institute of Electrical and Electronics Engineers Inc., 2023) Manjunath, K.; Kalpana, R.; Singh, B.; Kiran, R.
This article addresses a two-stage module based cell-to-cell active equalization topology based on a modified buck-boost converter for series connected Lithium-ion battery packs. In the proposed topology, initially module based equalizing currents are controlled. Subsequently, cell-based equalizers are controlled in parallel within each battery module. The proposed topology significantly reduces the balancing time by transferring higher balancing current from a strong cell to the weakest cell in a module directly. With the proposed topology's modularized design, reduces voltage stress on long strings of switches, resulting in improved performance with fewer components. The operating principle, control strategy and design constraints are analyzed in detail. The MATLAB/Simulink platform is utilized to demonstrate the feasibility of the proposed technique for balancing the energy in series connected battery cells. To reduce the complexity of the control approach, the digital control is implemented using an FPGA control board. Further, a laboratory prototype is developed to show the feasibility and operability of the proposed topology. © 1986-2012 IEEE.
A Zig-Zag Multiwinding Transformer Based AC-DC Converter for EV Battery Charger Using Interleaved Buck DC-DC Converter
(Institute of Electrical and Electronics Engineers Inc., 2024) Sinha, S.; Kalpana, R.
Electric vehicles (EVs) are depending on reliable and efficient battery charging infrastructure. This work provides a 2 set of three phase ac-dc converter-based power-quality (PQ) compliant IEEE-519 battery charging system. The zigzag multi-winding transformers (ZZMWTs) will play a role in reducing total harmonic distortion (THD) without the use of any power factor correctors or filter circuits. The secondary side star and delta arrangement of the ZZMWTs will have a phase shift of Â± 150. This paper focuses on designing, optimizing, and managing a DC-DC interleaved buck converter for EV battery charging in both constant current (CC) and constant voltage (CV) modes. The planned EV charger performance is assessed using the MATLAB/Simulink environment in terms of THD and PF. A laboratory prototype hardware arrangement of the suggested battery charger is used to validate the results while providing controlled feedback. To support the theoretical analysis, further experimental findings from the lab prototype are presented. Â© 2024 IEEE.