Abstract: In order to improve the efficiency of wireless transmission system, it is necessary to make the inverter circuit work in the soft switching state as much as possible and the working frequency as close as possible to the resonant point. Based on the above principle, analyzes the basic conditions for the inverter to enter the soft switching state, and combines the wireless transmission efficiency characteristics of wireless transmission system to obtain a phase-shifting control efficiency optimization method of wireless transmission system. By controlling the working frequency of the inverter circuit, it can work in the maximum inductive reactance point close to the resonant point of the wireless transmission system, so that the circuit can enter the soft switching state more easily under the control mode of phase shift control, so as to reduce the switching loss and improve the working efficiency of the wireless transmission system. The simulation results show that the control method is correct. Finally, a 650W wireless transmission system is used for experimental verification. The simulation and test results can reduce the loss of the wireless transmission system by more than 2 W, indicating that the control method can improve the system efficiency when applied to the wireless transmission system.

Key words: Full bridge phase shift, Wireless power transmission, Soft switch, Efficiency