Overview of CLLC Modulation Strategy

In this paper, the CLLC bidirectional resonant converter is the research object. From the perspective of control variables, including phase-shifted angle, duty cycle and frequency, its modulation strategies are classified into four groups to make up for the lack of comprehensive summary and clear classification of CLLC modulation strategies in current literature. The analysis process mainly uses fundamental harmonic analysis (FHA), assuming that the power flows from the primary side to the secondary side. Based on the same set of circuit parameters, the circuit driving sequence, electrical parameters, and voltage gain characteristics under different modulations are given. In addition, the advantages and disadvantages of various modulation strategies are also described and listed to provide engineers with a good design guide.