Hybrid Control Method of Full-Bridge LLC Resonant Converter Based on Electric Vehicle

The increasing demand for efficient electric vehicle (EV) charging systems has emphasized the need for high-performance DC-DC converters capable of maintaining high efficiency under wide load variations. This project presents a Hybrid Control Method for a Full-Bridge LLC Resonant Converter designed to enhance efficiency and stability in EV charging applications. The proposed approach combines Pulse Width Modulation (PWM) and Burst Control to address limitations in excitation current and narrow output voltage range under light-load conditions. By utilizing the resonant current energy during the burst-on period to support zero-voltage switching (ZVS) in PWM mode, the hybrid control achieves reduced switching losses, improved electromagnetic interference (EMI) characteristics, and a wider output voltage range. Furthermore, a PFM + PWM-Burst hybrid strategy is implemented to optimize performance under both light and heavy load conditions. Simulation results obtained using MATLAB/Simulink confirm that the proposed method effectively achieves ZVS operation, minimizes output ripple, and significantly improves converter efficiency across the full load range, making it well-suited for advanced EV charging systems.