The most widely used wireless power transfer (WPT) system is Series-Series (SS) compensated topology driven by a full-bridge or half-bridge inverter. In order to achieve zero-voltage switching (ZVS), the switching frequency of inverter should be above the resonant frequency so that it is not on the maximum efficiency point of coils. This paper provides a mathematical analysis of the ZVS condition and the efficiency characteristic of SS compensated WPT systems. An overcompensated design method for SS compensated WPT system is proposed in this paper, which can achieve the ZVS condition and the maximum transfer efficiency at the same time. The simulation and experimental results validate the design method. The measurement efficiency of the WPT prototype can reach above 90% over a wide operating range from 16% load to full load.
An Overcompensated Design Method for Series-Series Compensated Wireless Power Transfer System Jiaqi Tang Zhen Wei Tengfei Hu Qianfan Zhang