Design of Wireless Power Transfer System for Mobile Devices Based on Class E Amplifier

This paper addresses the dynamic impact of pickup relocation or removal on the topological configuration of the Electric field Coupled Power Transfer (ECPT) system, potentially leading to adverse transistor effects and operational anomalies. The study analyzes the ECPT system's core characteristics using the class E amplifier model, investigating the causes behind transistor current and voltage surges triggered by pickup detachment. A parameter design strategy is then proposed to achieve wide-load zero-voltage switching (ZVS) operation while maintaining a fixed operating frequency. To sustain ECPT system functionality in a post-pickup removal standby mode, a novel power regulation technique integrated into the DC/DC converter is presented. Through simulations and experiments, the feasibility and effectiveness of the proposed methods are verified.