A Variable Compensation Inverter Rectifier (VCIR) based Approach to Compensate for Coupling Variations in Wireless Power Transfer Systems

This paper introduces a new approach to compensate for coupling variations in wireless power transfer (WPT) systems using a variable compensation inverter rectifier (VCIR). The VCIR based WPT system can continuously compensate for misalignments and air-gap variations, and maintain a constant output power, by controlling the input voltages of two inverters at the transmitting side and the output voltage of one rectifier at the receiving side, while operating at a fixed frequency and maintaining soft-switching of the inverter and rectifier transistors. The VCIR builds upon the concepts of the recently proposed active variable reactance rectifier (AVRR) and variable compensation inverter (VCI), and achieves substantially higher range of compensation than both. This paper also presents a systematic methodology to design a VCIR based WPT system. The benefits of the VCIR approach are being validated using a 6.78-MHz 50-W scaled prototype capacitive WPT system.