Electro-thermal based junction temperature estimation model and thermal performance analysis for IGBT module

This paper presents an electro-thermal based junction temperature (T
j
) estimation method of insulated gate bipolar transistor (IGBT) power module. Firstly, the internal structure of IGBT and its transient characteristics are researched, through which the factors affecting the power loss as well as its basic influence rule are analyze and the multivariable loss calculation model is obtained. And then with the coupling of the loss and Foster model, the maximum T
j
is obtained. The method is validated against the simulation of both IPOSIM and finite element method, and the comparison of the results shows the differences were less than 4% which illustrates the accuracy of the estimation model. Finally, the correlation of the module's thermal performance with its internal structure is explored in ANSYS for optimization design. This model contributes to the reliability verification and more reasonable thermal design of IGBT module.