A Charge Control Strategy With Digital Implementation for LLC Resonant Converters

ABSTRACT This paper presents a novel peak power control strategy for LLC resonant converters, targeting renewable energy‐based hydrogen production systems. Unlike conventional charge control methods, PPC regulates the peak half‐cycle charge by adjusting the resonant capacitor's negative peak voltage and a feedback‐defined voltage increment, enabling fast and accurate power control. The proposed method features first‐order dynamic behavior with high bandwidth and phase margin, leading to improved stability and transient performance. A fully digital implementation based on a TMS320F280049C controller is developed, and a 110 V/24 V, 240 W prototype is built for experimental validation. Test results show that PPC achieves faster dynamic response and lower voltage deviation compared to time‐shift control and hybrid hysteresis control, while also enhancing robustness under overcurrent and short‐circuit conditions. These advantages make PPC a promising control solution for high‐efficiency and stable power conversion in hydrogen energy applications.