Variable-Frequency Critical Soft-Switching of Wide-Bandgap Devices for Efficient High-Frequency Nonisolated DC-DC Converters

This paper derives a variable-frequency critical soft-switching control method for nonisolated DC/DC converters using wide-bandgap devices. The critical soft switching control technique under maximum frequency trajectory is introduced to maintain zero voltage switching over a wide range of modulation ratios according to the load variation. The concept prevents turn-on losses that are typically much larger than the turn-off losses in SiC and GaN …