No/VOL: 09/2022 Page no. 158
Authors: Krzysztof Górecki , Paweł Górecki :
Title: Influence of the form of the thermal model on accuracy of computing DC characteristics of IGBT module
Abstract: This paper analyzes the influence of the form of the thermal model of the IGBT module on the accuracy of computations of their DC characteristics. Such a module contains several semiconductor dies in a common case. In such a module, the phenomenon of self-heating occurs in each semiconductor die and mutual thermal couplings between each pair of these dies. Considerations are made for the module containing 2 IGBTs and two diodes connected into one branch of the inverter and a thermistor. The investigations are carried out with the use of SPICE software, taking into account 4 types of thermal models of this module. The first one does not take into account either self-heating or mutual thermal couplings. The second takes into account only self-heating in individual semiconductor dies. The third model takes into account both thermal phenomena characterized by thermal resistances of a fixed value. The fourth model takes into account both thermal phenomena and the dependence of the thermal resistance on the power lost in individual semiconductor dies. The calculation results are compared with the measurement results obtained for three different cooling conditions. The range of application of individual models is discussed.
Key words: IGBT module, thermal model, self-heating, mutual thermal couplings, electrothermal analysis, SPICE