Evaluation of SiC devices in converter phase-leg at high temperature

SiC devices have obvious advantages comparing with conventional Si devices especially in high temperature range. This paper aims at developing a method of characterization SiC JFET conduction and switching performance in high temperature and calculating the loss of SiC JFET converters. Experimental results show that with SiC Schottky diode as anti-paralleling diode the reverse recovery in switching is improved and switching loss is less. Also, the turn-off time will decrease when the temperature rises, showing a better performance in high temperature. With the test results, the loss estimation method is developed. Then losses of two typical three-phase AC-DC-AC converters are calculated. Experimental results show that with Schottky diode as anti-paralleling diode, both conduction losses and switching losses can be reduced especially at high temperature.