Research on Optimal Operating Frequency of Wireless Power Supply System Based on Multiple Relay

Zero phase angle and constant current output characteristics of the system transmission loop have always been the basic transmission objectives of the wireless power supply system. In order to explore how to achieve this goal, this paper takes the five-coil multi-relay wireless power supply system as the research object, establishes the mathematical model of the system and deduces that the zero phase angle frequency of the transmitting loop is equal to the constant current frequency. Secondly, the resonant points of the system are simulated in MATLAB, and the sensitivity of the output current at each resonant point to the frequency change is analyzed to select the optimal operating frequency. Finally, a time-domain differential model was established in Simulink to verify the conclusion. When the frequency is 210.7kHz, the phase difference between the current and voltage of the transmitting loop is 0, and the system is least sensitive to frequency changes near this frequency point.