Research on Transmission Characteristics of Dual LCL Resonance Compensation Topology in Wireless Charging System

In response to the problems of traditional plug-in charging methods, wireless charging technology came into being. In order to solve the problem of complicated switching process from constant current charging mode to constant voltage charging mode in wireless charging, and the difficulty of control circuit design, this paper designs a bilateral LCL compensation resonance topology structure, in which additional compensation capacitors are connected in series with the secondary side compensation capacitor branch. Through the switching of the additional compensation capacitor, the smooth switching from the constant current to the constant voltage charging mode is realized. At the same time, by studying the influence of the coupling coefficient of the primary and secondary coils, the operating frequency of the system and the changing load during the charging process on the transmission efficiency of the resonant system, it is found that with the increase of the coupling coefficient, the transmission efficiency of the system gradually increases, but the coupling coefficient reaches 0.8 When the frequency splitting occurs in the system, the corresponding efficiency is not the maximum efficiency point when the system is working at the resonance frequency; under the same coupling coefficient, the greater the frequency, the higher the transmission efficiency; when the frequency and coupling coefficient of the system remain unchanged, with the load The increase in the transmission efficiency of the system will decrease.