Research on a New Control Strategy for Reducing Hard-switching Work Range of the Three-phase Interleaved LLC Resonant Converter

Based on the detailed analysis of the star-connected three-phase interleaved LLC resonant converter topology, this paper proposes a new control strategy of three-phase interleaved LLC resonant converter PFM mode combined with single-phase full-bridge LLC resonant converter PFM mode and phase-shift mode, which can greatly reduce the hard-switching work range of the three-phase interleaved LLC resonant in low output voltage and light output load case and is suitable for the high power conversion applications of wide range output. A three-phase interleaved LLC resonant converter based on the new control strategy is proposed for detailed analysis to verify the new control strategy's correctness and feasibility.