Fast and accurate Icepak-PSpice co-simulation of IGBTs under short circuit with an advanced PSpice model

A basic problem in the IGBT short-circuit failure mechanism study is to obtain realistic temperature distribution inside the chip, which demands accurate electrical simulation to obtain power loss distribution as well as detailed IGBT geometry and material information. This presentation describes an unprecedented fast and accurate approach to the electro-thermal simulation of power IGBTs which is suitable for simulating normal as well as abnormal conditions based on an advanced physics-based PSpice model together with an ANSYS/Icepak FEM thermal simulator in a closed loop. Through this approach, a significantly faster simulation speed with respect to conventional double-physics simulations, together with very accurate results can be achieved. A case study is given which presents the detailed electrical and thermal simulation results of an IGBT module under short-circuit conditions. Furthermore, thermal maps in the case of non-uniform threshold voltage/solder resistance/gate resistance among the cells are presented in comparison with the case of uniform distribution, evidencing the capabilities of studying short circuits of aged devices by the presented technique.