A Wireless Power Transfer System Topology with Automatic Switching Characteristics of Constant Current and Constant Voltage Output for Electric Vehicle Charging

Wireless power transfer system has the advantages of safety, reliability and convenience for electric vehicle charging. According to charging characteristics of lithium batteries used in electric vehicles and previous research on the loosely coupled transformer and compensation topologies, a wireless power transfer system design consisting of PS-SS and PS-SLCL compensation topologies is proposed in this paper. The charging mode of the system automatically changes from the CC mode to the CV mode with the change of the load impedance. Soft switching characteristics of the primary inverter can be obtained in the whole charging process. Topology parameters and transformer model dimensions are designed in terms of theoretical analysis on the system characteristics. Simulation results verify the constant current and constant voltage outputs of the system, and a 1kW experimental platform is built to verify the effectiveness of the proposed design. © 2020, Electrical Technology Press Co. Ltd. All right reserved.