62 W Auxiliary power supply for three-phase power converters using Infineon 1700 V silicon carbide MOSFET

Silicon Carbide (SiC), a wide band gap semiconductor, excels in its remarkable physical properties. Compared to silicon (Si), in particular the much higher breakdown field strength and better thermal conductivity enable great performance advantages for power devices. SiC MOSFETs can provide a significant reduction of conduction losses compared to Si devices and, at the same time, low switching losses even for high voltage classes. The 1700 V CoolSiC(TM) MOSFET from Infineon is an excellent choice for high-input voltage DC link systems like those found in auxiliary power supplies for three-phase converters. This paper will demonstrate how to simplify the current auxiliary power supply designs by developing a single-ended flyback reference board using Infineon’s 1700 V CoolSiC(TM) MOSFET in TO- 263 package. The efficiency of the reference board, CoolSiC(TM) MOSFET thermal tests, and critical functional tests of the reference board are also presented.