Double-side Phase Shift Control for Impedance Matching in Wireless High Power Transfer

In wireless power transfer system (WPTS), the control technique of the active rectifier (AR) is vital for improving the transfer efficiency of resonant network, expanding operating range of load and increasing power density. To minimize the power loss of resonant network in EV’s battery charging, this paper presents a double-side phase shift control (DPSC) strategy to achieve CC/CV charging and impedance matching simultaneously. Moreover, an implementation method to control the AR accurately and reliably with a novel phase-locked method is also presented. Next, in the whole charging process, the power losses of resonant network by using different control methods are compared. Finally, benefiting from the DPSC with the proposed phase-locked method, the WPTS not only obtains a high accuracy in steady state, but also achieves a good dynamic performance with the step change of RL and REref.