A Variable Compensation Rectifier with Enhanced Compensation Capability for Coupling Variations in Wireless Power Transfer Systems

This paper introduces a new variable compensation rectifier (VCR) for mitigating coupling variations in wireless power transfer (WPT) systems. The proposed VCR allows a WPT system to achieve continuous compensation and a constant output power over wide range of misalignments and air-gap variations without having to change the system's operating frequency. The VCR can achieve substantially higher compensation range compared to that of the recently proposed active variable reactance (AVR) rectifier while allowing an inherently simpler control technique. The paper also outlines a systematic methodology to design a VCR-based capacitive WPT system with a desired maximum compensation range. A proof-of-concept prototype VCR based system is developed and compared with an AVR based system. The VCR based system is demonstrated to achieve two times wider compensation range while maintaining the nominal output power.