78 W Auxiliary Power Supply for 22-KW Drive Using 1700 V Silicon Carbide MOSFET

Wide-bandgap silicon carbide (SiC) semiconductors are well known to have good potential for use in high-voltage, high-frequency and radiation hardened applications. In addition, the low ON resistance and compact chip size ensure low capacitance and gate charge. Consequently, system benefits include higher efficiency and faster operation frequency, also higher power density, which means smaller size, even lower system cost. 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 current auxiliary power supply designs by developing a singleended flyback demonstration board using Infineon’s 1700 V CoolSiC(TM) MOSFET in TO-263 7 leads package. Efficiency and thermal tests, and critical functional tests of this demonstration board are also presented.