Modeling and Simulation of a Phase-Shift Controlled LLC Resonant Converter

This paper performs a simulation study of the operation of a phase-shift controlled LLC resonant converter at frequencies above the resonant frequency. The circuit's performances at different phase-shift angles, loads and ratios between parallel and series inductances are analyzed. The output characteristics obtained from the simulations and their comparison with the theoretical results are discussed. The influence of different parameters on the output power regulation conditions while maintaining the ZVS conditions of the transistors in the "lagging" leg is analyzed. Simulations for continuous current mode have been implemented using OrCad PSpice. Good agreement between theoretical and simulation results is observed.