Faculty Publications
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Item An Integrated Onboard EV Charger With Wide Voltage Range Compatibility(Institute of Electrical and Electronics Engineers Inc., 2025) Kumar, V.; Prabhakaran, P.; Reddy, B.D.; Febin, J.L.F.Electric vehicles (EVs) typically employ separate onboard chargers and traction inverters for battery charging and motor operation, respectively. This paper proposes a bidirectional integrated onboard charger (BIOC) that utilizes a single power converter to perform both functions, thereby reducing cost, improving system compactness, and supporting fast charging. The proposed BIOC architecture is implemented using a totem-pole power factor correction (PFC) stage combined with an additional coupling unit. This configuration supports a wide range of battery voltages and is compatible with both AC and DC grid inputs. The BIOC incorporates active power decoupling (APD) to minimize voltage ripple at the battery terminals during high-voltage (HV) battery charging. Leakage current analysis of the totem-pole PFC stage confirms compliance with safety standards, and a detailed switch loss calculation procedure is presented. A comprehensive controller design is developed using State-Space Averaging (SSA) and Small Signal Modelling (SSM), followed by a K-factor method to ensure optimal performance across various operating modes. The proposed system is validated through simulations on a 2 kW Simulink model and experimental testing on a 400 W scaled-down prototype, demonstrating effective charging of an EV battery across a wide voltage range from both AC and DC grids. This work offers a unified, efficient, and cost-effective solution for integrated onboard EV charging. © 2013 IEEE.Item A Transformerless Bidirectional Active Switched Inductor-Based SEPIC High-Gain DC–DC Converter With Buck–Boost Capability(Institute of Electrical and Electronics Engineers Inc., 2025) Mandal, S.; Prabhakaran, P.; Dominic, D.A.; Parameswaran, A.P.The growing demand for efficient and compact power conversion systems in electric vehicles (EVs), renewable energy systems, DC microgrids, and both portable and stationary medical equipment has intensified research into non-isolated high-gain bidirectional DC-DC converters. Existing solutions often employ transformer-based topologies or coupled inductors, which introduce increased cost, size, and control complexity. This paper presents a novel transformerless bidirectional high-gain DC-DC converter based on a modified Single-Ended Primary Inductor Converter (SEPIC) architecture. The proposed topology incorporates an Active Switched Inductor (ASL) at the input stage to achieve a wide voltage conversion ratio while ensuring reduced voltage stress on the maximum power switches. A key feature of the converter is its ability to provide bidirectional buck–boost operation in both power flow directions, while maintaining a reduced component count and improved efficiency through synchronous rectification. The converter’s performance is thoroughly analyzed under both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). Furthermore, detailed small-signal modeling and closed-loop controller design are developed for both voltage-mode and current-mode control. A 200 W experimental prototype employing SiC MOSFETs is implemented to validate the theoretical analysis. Experimental results confirm the high efficiency, robust dynamic response, and practical feasibility of the proposed converter for next-generation power conversion applications. © 2013 IEEE.Item Novel sorted PWM strategy and control for photovoltaic-based grid-connected cascaded H-bridge inverters(Springer, 2025) Maheswari, G.; Manjunatha Sharma, K.M.; Prabhakaran, P.This paper proposes a novel sorted level-shifted U-shaped carrier-based pulse width modulation (SLSUC PWM) strategy combined with an input power control approach for a 13-level cascaded H-bridge multi-level inverter designed for grid connection, specifically tailored for photovoltaic (PV) systems, which avoids a double-stage power conversion configuration. In this methodology, every inverter generates a quasi-square output voltage waveform with a width that is intricately linked to the output power of its corresponding PV panel. The application of this SLSUC pulse width modulation technique with input power control in a solar energy-based 13-level grid-tied inverter facilitates precise maximum power point (MPP) tracking for each of the PV panels under uniform and non-uniform irradiation conditions and ensures the consistent maintenance of capacitor voltage balance. Moreover, this novel SLSUC PWM method for 13-level inverters offers a range of benefits, including a low total harmonic distortion (THD) in the output voltage of the multi-level inverter and higher inverter and MPPT efficiencies over the existing PWM techniques. To verify the efficacy of the proposed control method over existing techniques, a PV-based grid-connected multi-level inverter with the proposed control strategy undergoes modeling and simulation using MATLAB/Simulink. Then, experimental hardware-in-the-loop (EHIL) testing is conducted to confirm and evaluate its effectiveness. © The Author(s) under exclusive licence to The Korean Institute of Power Electronics 2024.