Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
5 results
Search Results
Item Magnetic Coupling Characteristics and Efficiency Analysis of Spiral Magnetic Power Pads for Inductive WPT System(River Publishers, 2022) Kishan, D.The inductive wireless power transfer system (IWPT) for electric vehicle battery charging works based on the principle of mutual induction (MI). The amount of power transfer from source to vehicle battery be contingent on the mutual inductance (MI) within the inductively coupled pads. This mutual inductance depends on the type of the inductive power pads, the distance among them, their positioning etc. This paper develops and study the inductive coupling characteristics of identical spiral circular and square inductive power pads. The coupling characteristics at various misalignments with different vertical distance between the coils is presented. In this work, the inductive power pads without using ferrite bars, and with ferrite bars are considered. The coupling characteristics of the spiral circular and square are computed using FEM simulations and validated with experimental results. This paper also investigated the power loss and efficiency analysis of the spiral inductive pads of the resonant IWPT system. © 2022 River Publishers.Item Three-Leg DC-DC Converter for Efficient Inductive Power Transfer of Electric Vehicles for Wide-Range Battery Applications(Institute of Electrical and Electronics Engineers Inc., 2023) Vinod, M.; Kishan, D.; Dastagiri Reddy, B.D.The design of an inductive power transfer system for different electric vehicle (EV) models with widely varied battery pack voltages has been a challenging task. The majority of modern EV models are equipped with 400 or 800 V battery packs. To charge both batteries efficiently, an additional dc-dc converter on the receiver side is employed, which reduces the overall system efficiency and also increases the cost. This letter proposes a reduced switch count novel converter to charge distinct EV models without degrading the efficiency of the system. The proposed converter has two operating modes, a voltage doubler mode to charge an 800 V battery and a current doubler mode to charge a 400 V battery at the same power level. MATLAB/Simulink simulations have been carried out to verify the performance of the three-leg converter for both 400 and 800 V batteries at 7.2 kW. Furthermore, a laboratory prototype of the proposed converter for 500 W has been built using the silicon carbide (SiC) devices, and the results obtained are provided. © 1986-2012 IEEE.Item An efficient battery swapping and charging mechanism for electric vehicles using bat algorithm(Elsevier Ltd, 2024) Vani, B.V.; Kishan, D.; Ahmad, M.W.; Naresh Kumar Reddy, B.N.K.The recent surge in electric vehicle (EV) adoption has presented various challenges, notably in the charging and discharging processes of EV batteries, each characterized by unique traits. While conventional charging stations remain popular, battery swap stations (BSS) offer a compelling alternative, addressing issues like prolonged waiting times and potential battery degradation from fast charging. BSS, with its extensive array of battery systems, ensures efficient services for EVs. However, meticulous planning for the charging and discharging operations is imperative for both BSS and the overall grid to guarantee optimal functionality. This paper proposes an efficient approach to enhance the efficiency of battery swapping and charging mechanisms (BSCM) for electric vehicles, leveraging the bat algorithm. The BSCM is conceived as a system that incorporates both the battery swapping mechanism (BSM) and the battery charging mechanism (BCM). The key contribution lies in designing an effective BSCM where the BSM functions as a manager, handling battery swapping requests from EV users, while the BCM acts as a supporter, interfacing with the grid to regulate battery charging and discharging power. To efficiently address the mixed-integer nonlinear program (MINLP) inherent in this system, a Bat algorithm is developed. The results clearly demonstrate the effectiveness of the proposed algorithm in efficiently addressing large-scale problems, producing solutions that closely approach optimality. It promptly achieves a substantial reduction in battery swapping energy by 30% and 24%, respectively, and significantly enhances charging station utilization by 25% and 21% compared to the LSTM-Based Rolling Horizon Approach and Bilevel Optimization Approach. Additionally, the algorithm showcases remarkable improvements in battery swapping performance, boasting a 25% and 19% enhancement, and noteworthy increases in charging station utilization by 20% and 17% compared to the aforementioned approaches. This enhancement in the energy exchange with grid and regulation contributes to the overall efficiency and sustainability of electric vehicle operations. © 2024 Elsevier LtdItem 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 An Integrated EV Battery Charger With Three-Level Boost PFC Converter and H5-Bridge Based Bidirectional DO-CLL Series Resonant Converter for Wide Battery Voltage Range(Institute of Electrical and Electronics Engineers Inc., 2025) Vinusha, B.; Kalpana, R.; Kishan, D.This article proposes an efficient two-stage ac–dc converter for off-board electric vehicle charging applications over a wide range of battery voltages. The proposed charger integrates a three-phase three-level boost power factor correction (TL-BPFC) converter with a bidirectional dual-output CLL (DO-CLL) series resonant converter. In the ac–dc conversion stage, three switches are controlled using a hysteresis technique to enhance input power quality. The second stage, responsible for dc–dc conversion, incorporates an H5-bridge on the primary side and a voltage doubler circuit on the secondary side, providing decoupled outputs through two high-frequency transformers (HFTs) connected to resonant tanks. This configuration allows flexible adjustment of the resonant tank inputs, which can operate in full-bridge (FB), half-bridge (HB), or inactive (IA) modes. This design provides a key advantage of a wide voltage range during forward and reverse operation using reconfigurable H5 bridge. Additionally, the switches in the DO-CLL achieve zero-voltage switching (ZVS) during turn-on, and the identical HFTs minimize the cross-coupling effect, to enhance the efficiency. A scaled-down laboratory prototype of the off-board EV charger is developed to provide two distinct outputs of 400 V and 200 V, achieving an overall efficiency of 97.6%. © 1982-2012 IEEE.