Faculty Publications
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Item Primary side control strategies for battery charging regulation in wireless power transfer systems for EV applications(John Wiley and Sons Inc, 2024) Vinod, M.; Kishan, D.; Kannan, R.; Iqbal, A.; Sulthan, S.Resonant inductive-based wireless power transfer (WPT) for battery charging has potential applications in electric vehicles (EVs). The EV battery charging process requires the regulation of both charging voltage and current. Duty ratio or frequency control is generally preferred to manage the power flow between the transmitter and receiver coils in the WPT system. In the case of WPT charging, misalignment between the coils and parameter variations are unavoidable issues that result in changes to the output power. Therefore, it is essential to control the power flow to maintain constant current (CC) and constant voltage (CV) modes during battery charging. To address these challenges, various primary-side control techniques, such as asymmetric clamped mode (ACM), asymmetric duty cycle (ADC), and phase-shift (PS) fixed frequency control strategies, have been proposed for WPT systems. This paper conducts a comparative analysis of these control methods, considering their output voltage ranges and their ability to maintain zero-voltage switching (ZVS) for the entire control range. Furthermore, the paper presents a generalized design for reduced-order small signal modelling, utilizing an extended describing function. The designed controller, based on small signal modelling, will undergo real-time testing to evaluate its dynamic performance in the series-series resonant converter. © 2023 The Authors. IET Power Electronics published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.Item Efficient and cost-effective wireless CC/CV charging for electric vehicles: A bipolar duty cycle approach(Elsevier Ltd, 2024) Vinod, M.; Kishan, D.; Dastagiri Reddy, B.D.; Nagendrappa, N.Inductive Power Transfer (IPT) has gained significant popularity in recent times, particularly in electric vehicle (EV) battery charging applications. To achieve optimal battery charging, it is imperative to implement both constant current (CC) and constant voltage (CV) modes of operation. Traditionally, CC/CV modes are attained through conventional phase shift techniques, frequency modulation schemes, the use of active converters, and additional compensator circuits and coils. However, these conventional methods not only reduce system efficiency but also escalate overall costs and control complexity on the onboard side. This article proposes a novel bipolar duty cycle control strategy for a series–series resonant IPT system, aiming to achieve CC/CV modes of operation. The proposed control strategy increases the number of switches operated with zero voltage switching, compared to other fixed-frequency phase shift control strategies across a wide load range. Furthermore, the article provides a detailed procedure for implementing the voltage and current compensator. Additionally, it describes the construction of a one-kilowatt laboratory prototype using Sic devices, presenting the obtained results. The peak measured DC–DC efficiency of 93.8 % is achieved at a distance of 150 mm, and the efficiency has also been evaluated under misalignment conditions. © 2024 Elsevier LtdItem A dual full-bridge series-series resonant IPT system for ultra-wide-range electric vehicle battery applications(Springer Science and Business Media Deutschland GmbH, 2025) Vinod, M.; Kishan, D.The design of inductive charging systems presents a significant challenge for various electric vehicle models, each equipped with diverse battery packs ranging from 200 to 800 V. Typically, DC–DC converters, along with diode bridge rectifiers or controlled rectifiers, are employed to accommodate this wide battery voltage range. However, this conventional approach increases vehicle weight and introduces greater control intricacies. In response, this article proposes a wide-gain converter with two sets of coupled coils to charge batteries of different voltage ranges without compromising system efficiency. The proposed system operates in four modes: voltage doubler mode, current doubler mode, full-bridge mode, and half-bridge mode, which has high voltage gain, high current gain, medium voltage gain, and low voltage gain operations. The simulations have been performed using MATLAB-Simulink software to validate the efficacy of the dual full-bridge converter across various battery voltages (800 V, 400 V, and 200 V) and power levels. Furthermore, a laboratory prototype has been built with SiC devices to further validate the proposed converter. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.