Comparison of 6.5 kV silicon and SiC diodes

Silicon carbide (SiC) devices offer many advantages for the power electronics field. Even though there are commercial SiC diodes available, their use is limited to low power applications. This paper presents a SiC PIN diode module for medium voltage converters. The module, which has a rating of 6.5 kV and 1000 A, is compared to the commercial 6.5 kV, 1200A Si diode DD600S65K1. The analysis is based on the static behavior (on-state and blocking characteristic) and exemplary waveforms for diode turn-on, diode turn-off and IGBT turn-on transients at 3000V and 1000 A. Additionally, switching losses extracted out of measurements are plotted for currents between 50 and 1000A at junction temperatures of 25 and 125°C.