LLC Resonant Converter with Partial-Power Auxiliary DC/DC Module for Wide-range Output Applications

This paper proposes LLC resonant converter with a partial-power auxiliary DC/DC module for wide-range output applications. In which, the LLC resonant converter operates near the resonant frequency to maintain high efficiency, while only the partial power is processed by the auxiliary DC/DC module to offer the wide-range output voltage capability. Therefore, the proposed topology achieves higher efficiency than the conventional two-stage structure. A hybrid control strategy combining PI control and current prediction control is presented to implement the proposed design. The proposed LLC resonant converter is validated by the experimental results, which can achieve 24-72V wide-range output voltage regulation without wide-range frequency control.