Design of a Wireless Power Transmission Control System Based on the Phase-Shift Variable Angle

To increase the transmission efficiency of a wireless power transmission system while ensuring high stability and low cost, a two-degree-of-freedom two-sided control strategy to control the phase-shift duty ratio of the triggered pulse of the primary inverter and the angle between the resonant current and the AC voltage of the secondary side is proposed. The control strategy does not require additional DC-DC converters and components, and only some parameters of the basic circuit can be adjusted. The zero-voltage switching (ZVS) of all the MOSFETs in the system can be achieved by adjusting the shift duty ratio and power angle, and the current and voltage on the load side can be adjusted in real time. First, the basic principle of the two-sided control and the relationship of the phase angle are analyzed, and the operating range is determined by analyzing the operating modes on both sides. Second, the power loss of each link is analyzed, and the best operating point is determined. Subsequently, the system structure and the control strategy of the proposed method are presented. The two-sided control strategy is verified experimentally, which shows that the system can achieve the ZVS of all the MOSFETs while maintaining a constant current output.