Design for constant output voltage and current controllability of primary side controlled wireless power transfer system

This paper proposes a new wireless power transfer (WPT) control technique, which employs primary side controller and series-series (SS) or series-parallel (SP) compensation to achieve constant voltage (CV) charging or constant current (CC) charging without the information of the variable load. Through the variation of primary side resonant current, the charging voltage or charging current is estimated and dual-side wireless communication is avoided. Then, not only is the receiver more compact, but also the stability of WPT system is further ensured. Based on the simulation and experimental results, it show that when the load varies, CV charging for SS compensation and CC charging for SP compensation are achieved by the PI controlled phase shift H-bridge inverter. The proposed system is suitable for the application that size and weight of the receiver is limited.