Comparative Study of PSFB Converter Efficiency for Various GaN Semiconductor Devices

This paper aims to provide a comprehensive understanding of the semiconductor selection process for the inverter of a Phase-Shifted Full-Bridge (PSFB) converter supported by simulation and measurements.We compare three semiconductor technologies, Si, SiC, and GaN, based on their zero-voltage switching (ZVS) capabilities.The output capacitance of the switch highly influences the ZVS range of the converter.Wide band-gap devices have smaller output capacitances and thus, allow the extension of the ZVS range, without additional hardware.This resaerch strengthens the influence of output capacitance finetuning on the converter efficiency when selecting the semiconductor switches.The comparison is supported by simulation in the program PLECS for a whole family of GaN transistors.The work herein presents a detailed analysis of the advantages and limitations of each semiconductor technology, thereby providing insights and recommendations for selecting the most suitable semiconductor for high-efficiency PSFB converters.The results are supported by a measurement on the 600 W, 100 kHz laboratory model of the PSFB converter.