Combination of Forward-Voltage Measurement and Short-Circuit Detection for High-Voltage RC-IGBTs

One possibility to determine the collector-current direction of high-voltage IGBTs is the forward-voltage measurement via the high-voltage desaturation (HV DESAT) method. In this paper the blocking capacitance of the DESAT diodes is used to detect short-circuits, without impairing the ability of the forward-voltage measurement. The presented detection is able to distinguish between short circuits, like low- and high-inductive type 1 as well as type 2 and switching transients during normal turn-ON.