A single-wire capacitive power transfer system with large coupling alignment tolerance

Abstract

This paper introduces a new Wireless Power Transfer (WPT) system based on single pair of electric field coupling without a current return path. Such a single-contact Capacitive Power Transfer (CPT) system helps to enhance the coupling tolerance between the coupled plates. A class E converter is designed to drive an LCLC resonant circuit to boost the voltage at the primary side of the coupling plate, while a CLCL resonant circuit is used to boost the output current to the load. A practical prototype is built, and it has demonstrated that 3.8 W of power can be transferred across a single pair of copper coupling plates (100mm ×100mm) at full alignment. And it has found that the single-wire CPT system has a large coupling tolerance against both lateral and angular misalignments between the coupled plates.