Impedance Buffer-Based Reactance Cancellation Method for CLC-S Compensated Wireless Power Transfer

Due to the inevitable variation of component parameters, interference of ferromagnetic foreign body, active regulation of operation frequency, and rectification effect caused virtual capacitance or inductance, zero-phase-angle (ZPA) operation and zero-voltage switching (ZVS) could hardly be maintained without extra control strategies, especially for high-order compensation WPT system. Accordingly, this article proposes and implements an impedance buffer-based reactance cancellation method for a capacitor-inductor-capacitor-series (<italic>CLC-S</italic>) compensated wireless power transfer system with robust ZVS. The proposed reactance cancellation method adopts a synchronous impedance buffer series connected with the <italic>CLC</italic> compensation network to realize full-range ZPA operation. It can also be regulated to ZVS switching conditions under a large tolerance of the abovementioned issues. In addition, the proposed concept holds the characteristic of communication-free, feedback-free, simple control, and no strict constraints imposed by parameters in high-order compensation. Theoretical analysis, simulated, and experimental results are given to verify the feasibility of the proposed reactance cancellation method.