Parameter Design Method With Constant Output Voltage Characteristic for Bilateral LC-Compensated CPT System

In order to solve the problem that the output voltage of bilateral LC-compensated capacitive power transfer (CPT) system varies with the variation of load and equivalent coupling capacitance, this article presented a parameter design method that maintained the output voltage constant and guaranteed a high power factor. The mathematical model of the bilateral LC-compensated CPT system was established. The characteristic of the primary and secondary LC-compensated network was analyzed, and then, the conditions remaining a constant output voltage with varying load and coupling capacitance were determined. The relationship between the power factor and the load versus equivalent coupling capacitance was given. With the proposed parameter design method, a 100-W bilateral LC-compensated CPT experimental setup was constructed. The output voltage changes from 55.0 to 58.7 V and the power factor varies from 0.902 to 0.977 when the load and coupling capacitance vary from 30.2 to 70.8 Ω and from 310 to 1490 pF, respectively. Both the simulation and experimental results have verified the characteristic of constant output voltage and the effectiveness of the proposed parameter design method.