Double‐sided CL compensation topology based component voltage stress optimisation method for capacitive power transfer charging system

Abstract

A double-sided capacitor–inductor (CL) compensation topology is proposed for high-power capacitive power transfer (CPT) charging systems with a component voltage stress optimisation to alleviate the voltage stress on passive components and coupling interfaces. First, detailed analysis of the compensation topology characteristic is carried out based on fundamental harmonics approximation analysis method to yield the voltage stress functions against system's parameters. Then, a voltage stress optimisation is presented. Third, system component voltage stress can be reallocated effectively according to the desired requirement by adjusting system parameters accordingly. With the proposed voltage stress optimisation, a CPT prototype is set up to verify the proposed method performance. As per the experiment results, the efficiency of the prototype reaches 87.47% with 1494 W output power from DC to DC at the 1 MHz switching frequency. Besides, the maximum voltage stress is significantly reduced compared to that without optimisation.