A Novel Current Sharing Method by Grouping Transformer’s Secondary Windings for Multi-phase LLC Resonant Converter

摘要

A novel current sharing method is proposed for multi-phase LLC resonant converter in this paper. The proposed method is achieved by grouping secondary windings of the transformer in each phase, which is very simple with no additional components or control strategies, and can achieve good current sharing performance even when resonant component error is large. Both theoretical analysis under first harmonic approximation assumption (FHA) and simulation results demonstrate the current sharing good performance. A 960W two-phase LLC resonant converter prototype was built and tested to verify the proposed method.