Design and Performance Comparison of Si and SiC MOSFETs for Dual Tank LCL-Type Series Resonant Converter

This paper presents operation, analysis, design, simulation and experimental results for a fixed-frequency half-bridge dual tank high-frequency (HF) transformer isolated soft switching LCL-type series resonant dc-dc converter and its performance comparison when Si and SiC MOSFETs are used. Operation of the converter is presented with operating waveforms and equivalent circuits for different intervals. Approximate analysis approach is used to obtain design curves and design equations. A 300 W, 300 V output converter switching at 100 kHz is designed to illustrate the design procedure. PSIM simulation results are given to evaluate the performance of the designed converter. An experimental converter is built to test the performance of Si and SiC MOSFETs. It is shown that SiC MOSFETs operate with an efficiency of 97.1% at full load and at 93.7% at 20% load. This converter can be used in alternate energy applications, such as PV array, and can provide step-up operation with HF transformer isolation and high efficiency.