LCL — LCCL voltage source inverter with phase shift control for wireless EV charger

Abstract

In the wireless power transfer (WPT) system for EV charger, the resonant inverter is mainly used as power converter. The LCL primary circuit can reduce the inverter current while amplifying the primary current by the ratio of Lb/Leq. This paper presents the LCL — LCCL resonant inverter. The effects of non-linear load and high order circuit are focused by considering the frequency response and diminished by adding series capacitor with secondary pad. The high order component elimination is validated by the frequency response. The switching patterns can be modified to control inverter current which affects the output power. The phase shift control is selected in this paper which is the symmetrical voltage property. The blocking capacitor is not needed. The modifying square wave voltage will affected to the phase between voltage and current of inverter. The phase protection is used for protect non — ZVS condition. Finally, the proposed topology is validated by the experiment.