Redefinition of safety operating area (SOA) considering transient thermal dynamics of IGET module

In power electronics converters, the insulated gate bipolar transistors (IGBTs) are easy to fail during possible large disturbance on the source or load side. This paper redefines the safety operating area (SOA) by proposing a relationship between the junction temperature rising time and the disturbing current on the device. An improved temperature-dependent Cauer-type thermal model is used to uncover the junction temperature rising mechanism of IGBT under transient current steps. The SOA results can be used in the protection design for the IGBT modules.