Design Methodology Based on Model Equivalence and Small Signal Modeling of CLLC Resonant Converter

With the advantages of soft switching and bidirectional power flow capability, CLLC resonant converter has application prospect in new energy systems. However, the complexity of parameter design and control design caused by the asymmetry of forward and backward structures restricts the application of the converter. Aiming at this issue, this paper proposes a symmetrical parameter design method for CLLC resonant converter (dissymmetry structure) based on model equivalence. The parameter design method can realize the consistency of forward and backward work characteristics. In addition, this paper presents a small signal model of CLLC resonant converter based on the extended function description method, which can be used as the basis for control design. Finally, the accuracy of the proposed parameter design method and the small signal model is verified by simulation.