A Novel Compensation Circuit of the Capacitive Power Transfer System With High Performance of Anti-Misalignment

Abstract

Capacitive power transfer (CPT) techniques have garnered significant attention in recent years. However, the misalignment of the coupler can lead to variations in the coupling coefficient, which further degrees the reliability of the CPT system and influence the lifetime of loads. In fact, a high-performance CPT system should not only realize nearly input zero phase angle (ZPA), constant output, and soft-switching of MOSFETs, but also exhibit exceptional anti-misalignment performance. Based on the double-sided LC compensation circuit, the LCLC-L compensation circuit with high misalignment tolerance is proposed and systematically analyzed in this paper. The redundant compensation capacitor is removed to reduce the volume of the compensation circuit and an additional L-C circuit is added to regulate the output characteristics of the CPT circuit. The proposed CPT circuit can also realize nearly input ZPA, soft-switching, and constant output. Besides, without complex control strategy, the output current of the proposed CPT circuit can maintain constant even though the distance of the coupler misalignment is large. Finally, the double-sided LC-compensated CPT prototype and the LCLC-L-compensated CPT circuit with the output current of 2 A and the maximum output power of 120 W are built to verify the analysis. Compared to the double-sided LC-compensated CPT circuit. The output current of the proposed CPT circuit is basically unaffected by the coupler misalignment.