A study of switching-self-clamping-mode "SSCM" as an over-voltage protection feature in high voltage IGBTs

In this paper, we study the switching-self-clamping-mode "SSCM" in high voltage IGBTs in terms of device physics and circuit operation. We present analysis for the HV-IGBT failure mode when operating in SSCM due to an unstable negatively damped system and the design consideration taken into account for avoiding such mode of operation. This enables the introduction of an over-voltage protection feature during device turn-off to add to the existing over-current protection capability under short circuit conditions.