CLLLC Resonant Converter with Full-Bridge Half-Bridge Switching for Improved Voltage Gain Range and Light-Load Efficiency

In this paper, a 1 kW CLLLC resonant converter with 400 V DC bus and 36-60 V battery voltage is designed, achieving wide voltage gain range through hybrid pulse frequency modulation (PFM) and phase-shift (PS) control, as well as full-bridge and half-bridge configurations. This paper briefly introduces the design methodology of CLLLC based on FHA and then analyzes the improvement in light-load efficiency provided by the HB-HB mode. Finally, the prototype with SiC MOSFETs on the high-voltage side is built and the experimental results validate the theoretical analysis.