Load-Independence-Based Composite Compensation Network and Control Strategy for Wireless Electric Vehicle Charging System

Nowadays wireless charging for electric vehicles has become popular in numerous situations by reason of safety and convenience. In this article, a composite compensation network and the corresponding charging control strategy aiming at optimizing the transmitting efficiency of the system and achieving constant current (CC) output and constant voltage (CV) output are proposed. First, the composite compensation network is analyzed by the equivalent circuit model as a reference. Second, based on the realization of CC/CV output, by analyzing the relationship between charging current/voltage and duty cycles of both DC-DC converters, the optimal duty cycles of both converters can be found. The purpose is to obtain the maximum transmission efficiency. Finally, the experimental results show good agreement with theoretical analysis, proving that the proposal can realize CC/CV charging and optimize the transmission efficiency.