High-speed electro-thermal simulation model of inverter power modules for hybrid vehicles

Temperature and temperature variation cycles of insulated gate bipolar transistors (IGBTs) are important variables for reliability assessment of inverter power module (IPM) applied in hybrid vehicles. Conventional electro-thermal (ET) simulation based on physics device model has been considered as an accurate method, but it is difficult to conduct a long real-time (over 10 min) thermal simulation as required in hybrid vehicles. In this study, a fast ET simulation model for long real-time thermal simulation of three-phase IGBT IPMs is presented in which the consideration of inverter/motor power train modelling, determination of simulation time step, calculation of temperature-dependent power losses as well as thermal network are discussed in detail. The advantage of the proposed simulation model is the IGBT temperature and variation cycle with power cycles of vehicles can be simulated at a fast speed without significant loss of accuracy. Device temperature over 10 min of real-time operation for a three-phase IGBT IPM has been simulated and validated by an experimental test.