The investigation of electro-thermal sub-strong coupling model of IGBT module

The junction temperature prediction of IGBT module is related to its temperature and current, so it involves coupled electro-thermal calculation. This paper proposes electro-thermal sub-strong coupling model of IGBT modules. Due to the electro-thermal indivisibility of IGBT module, this paper only considers part of coupling terms under the condition of ensuring the accuracy of the calculation. The formula of collector-emitter saturation voltage with current and temperature in IGBT chip is derived. By the method, the equivalent resistivity of IGBT chip is extracted. Finally, the sub-strong coupling model is used to simulate the temperature distribution of IGBT module. The accuracy of the model in predicting internal temperature is demonstrated of the IGBT module successfully by comparing the simulated results to experimental data.