Soft-Start Strategy for LLC Resonant Converters Based on Dual-Pulse Modulation

Due to its superior efficiency and high power density, the LLC resonant converter has become a prevalent choice in modern power electronic applications. However, during startup, the excitation of the resonant circuit can result in excessive resonant current, compromising system stability and reliability. This study introduces an innovative approach to soft-start control method that introduces dual-pulse modulation to replace conventional pulse-width modulation (PWM). This approach effectively suppresses resonant current during the startup phase, reduces inrush current, and significantly minimizes output voltage ripple. Finally, The effectiveness of the proposed method is validated through simulations by comparing it with traditional soft-start control strategies.