Interleaved LLC Resonant Converter with Hybrid PSM/PFM Control for Wide Voltage Gain Applications

This paper proposes a dual-phase interleaved LLC resonant converter with hybrid control strategy. By integrating phase shift modulation (PSM) and pulse frequency modulation (PFM) slope modulation techniques, the scheme achieves smooth mode transition without added switches or topology modification, effectively suppressing dynamic current impact during switching. Continuous wide voltage gain regulation from 0.55 to 1.83 times is realized within narrow frequency range (around 100kHz resonant frequency). A phase¬shifting current-sharing strategy is adopted for the two-phase interleaved configuration to ensure balanced current distribution. Experimental verification is conducted on a 200W prototype with 35-64V input/output voltage range, demonstrating the LLC's zero-voltage switching (ZVS) characteristics, wide gain regulation capability and current-sharing performance under the proposed hybrid control strategy.