Optimal Design of Control Strategy for Full-Bridge LLC Converter

Based on the full-bridge LLC converter, this paper proposes a hybrid control strategy for input voltage fluctuations. The specific control strategy is as follows: 1) When the input voltage is stable, the PID controller is used. Combine the FM control working mode with the phase shift control working mode; 2) When the input voltage fluctuates, the digital direct controller is used. By direct frequency modulation or direct phase shift control, the fluctuation of the resonant current and the resonant capacitor voltage is reduced, and the output voltage is quickly adjusted.