Time-Domain Efficiency Optimization Evaluation for Series Resonant Converter with Variable Frequency plus Shift Phase Control

This paper discusses the efficiency optimization of the dual-bridge series resonant converter (DB-SRC) under variable frequency modulation (VFM) plus phase-shift modulation (PSM). The FHA analysis method is convenient to analyze DB-SRC. However, the accuracy of its approximation results on the efficiency optimization requires an in-depth research. Therefore, the results from the time-domain (TD) analysis and fundamental harmonic approach (FHA) analysis are compared in this paper. The TD analysis method is firstly used to obtain the normalized parameters in DB-SRC such as peak tank current and transmission power, then, they are compared with their corresponding results from FHA. Furthermore, based on the results from TD analysis, the efficiency optimization method with VFM+PSM is proposed and compared with the optimization results from FHA analysis method, which shows that, two optimization results are similar. Finally, the TD analysis results and efficiency optimization method is verified by simulation and 1.4kW experimental prototype.