EV's Battery Charger Integrated with High Power Density and Efficiency

The objective of the conducted study on power conversion structures is to enhance the power density and efficiency of electric vehicles (EV s) while maintaining an affordable cost. The study suggests a novel approach to charging batteries for electric cars (EVs) by integrating low-voltage dc-dc converters (LDCs) and nonisolated onboard chargers (OBCs). This method involves sharing the mechanical components and semiconductor devices and is proposed as a solution to meet the increasing demands for EV s. The size of LDCs is significantly smaller when compared to a standard non-integrated charging system. The integrated scheme presented here is formulated based on a thorough analysis of the vehicle's different modes of operation in real-world driving scenarios. The OBC employs an asynchronous control approach to enhance system performance. The LDC system integrates two LLC resonant converters. These converters utilize a common transformer and components on the secondary side. A proposed strategy for enhancing the efficiency of each Local Distribution Company (LDC) involves the regulation of duty and frequency. The Low Dropout Regulator (LDC) functions throughout a broad spectrum of voltage levels for both input and output configurations. The objective of this presentation is to assess the efficiency of the proposed system through the presentation of a theoretical analysis, practical recommendations, and experimental results obtained from a 6.6 kW OBC and 1.9 kW LDC. The combined volume of these two devices is 1.87 liters, and their individual peak efficiencies are 97.13% and 97.3%, respectively. Furthermore, a comparative analysis is conducted to assess the efficacy of the recommended system.