A Constant Output Capacitive Wireless Power Transfer System Based on Parity-Time Symmetric

Abstract

In existing capacitive wireless power transfer (CPT) systems, the coupling capacitance of the traditional couplers is usually small, which will lead to a significant decrease in the power transfer capability when the transfer distance increases. Thus, it is a big challenge to achieve stable output power and constant transfer efficiency under different coupling capacitance. In this work, the circuit model of the CPT system with double-side LC compensation network is established firstly. Then, based on the parity-time (PT) symmetric theory, a primary-side control strategy is presented to achieve stable output power and constant high transfer efficiency when the coupling capacitance changes. Finally, the experimental results show that when the insertion depth of the stack array coupler changes from 60 to 180 mm, the output power of the proposed CPT prototype is almost stable at 25W, and the transfer efficiency is kept at around 88%, which verifies the feasibility and effectiveness of the proposed design.