Coils and Compensation Circuit Design Reduces Power Pulsation and Optimizes Transfer Efficiency in the Dynamic Wireless Charging System for Electric Vehicles

Abstract

This paper presents a method of designing coils and compensation circuits to reduce output power pulsation, optimize transfer efficiency for electric vehicle dynamic wireless charging systems. The transmission lane is modularly designed. Each module has three short-track transmitter coils that are placed closely together along the moving track of the receiver and connected to a single inverter. The designs of the transmitter and receiver coils are analyzed by finite element analysis to reduce the variation of the coupling coefficient. Then the coupling coefficient is analyzed to identify the characteristics of the dynamic wireless charging lane. The double-sided LCC compensation circuit is designed according to the optimum load value to obtain maximum transfer efficiency. The SIC devices are used to improve the efficiency of the 85 kHz resonant inverter. A 1.5 kW dynamic charging system prototype is constructed. Experimental results show that the average system efficiency of 89.5% is obtained, and the output power pulse rate is ±9.5% in the dynamic charging process.