Robustness test and failure analysis of IGBT modules during turn-off

Considering the typical operational conditions of railway traction applications, this paper proposes an insightful study of the failure mechanism of IGBT modules when exposed to various limit load conditions during turn-off. First, the results of extensive experimental analysis are presented. These are based on a dedicated test-circuit and point out a repetitive failure mechanism. This is subsequently investigated by means of simulations based on a compact model which includes all major and secondary electro-thermal effects (i.e. latch-up). The results enable an interpretation of the observations and point out how the limits of transient safe operation can be significantly reduced by parasitic effects.