Research on Current Sharing Characteristics of 2-phase-90° Interleaved Parallel LLC Resonant Converter Based on Flexible Resonant Capacitor

In order to solve the problems of unbalanced 2-phase resonant currents and output currents of the traditional 2-phase parallel LLC resonant converter, it is proposed to connect a flexible resonant capacitor with small capacitance value in parallel at the ends of two resonant capacitors of the 2-phase LLC resonant converter. The result shows that the use of flexible resonant capacitor can realize the converter current sharing. The paper analyzes the working principle and current sharing characteristics of the 2-phase 90° interleaved parallel LLC resonant converter based on flexible resonant capacitor, simulates the PSIM circuit, builds an experimental prototype with 500V input and 200V/2kW output, and verifies the reasonableness and validity of the proposed scheme through simulation and experiment.