A Comparison Study of Compensation Topologies for Capacitive Power Transfer

Abstract

The compensation topology as the key factor affecting the performance of the capacitive power transfer (CPT) system has been extensively studied. This paper compares the characteristics of the double-sided LC, LCL and LCLC compensation topologies for the CPT system. According to Kirchhoff's voltage law (KVL), the output characteristics of the three topologies are calculated. Considering that the system frequency varies in practice, the output current, current gain and output power of three topologies at different operating frequencies are analyzed. The 1.5kW CPT systems with three different topologies are modeled and simulated respectively to verify the analysis. Meanwhile, this paper compares the characteristics of the LCLC compensation topology and its four-coil configuration. Though the four-coil configuration can be equivalent to the LCLC compensated CPT system under certain conditions, the differences are found in the aspects including the voltage gain, the current gain, and the output power at different operation conditions. A 1.5kW double-sided LCLC CPT prototype is built to verify the theoretical analysis.