A Novel Method for Load Voltage Regulation and Power Transfer Efficiency Maximization in Wireless Power Transfer Circuits Exploiting a Switching Voltage Regulator

This paper proposes a novel control strategy for wireless power transfer (WPT) circuits that achieves both load voltage regulation and maximum efficiency control for varied resistive loads. The proposed method is based on the characteristic that the input impedance of a switching voltage regulator depends on its input voltage. The switching regulator is utilized not only for load voltage regulation but also for impedance conversion to maximize the transfer efficiency. External communication circuits for feedback control from the secondary side to the primary side are unnecessary as the controllers on both sides operate independently. Experimental results approximately match the derived theoretical values and validate the proposed method.