A 3-D Temperature-Dependent Thermal Model of IGBT Modules for Electric Vehicle Application Considering Various Boundary Conditions

With the development of power electronic converters (PECs), the thermal properties of high-power insulated gate bipolar transistor (IGBT) module are of significant importance in the reliability analysis, thermal design, and management of PECs. However, the present commonly used three-dimensional (3-D) thermal network model, still has limitations in accurately obtaining the junction temperature of IGBT modules. Particularly under high-temperature conditions, its performance is not ideal. This paper proposes a 3-D thermal network model considering the temperature effect of constituent materials, which has been efficiently obtained using four sets of finite element method (FEM) transient thermal simulation. By employing a two-step extraction (TPE) method, the thermal parameters including the conductance and capacitance of crucial nodes are fully identified based on the reconstruction matrix of virtual temperature. Additionally, the identified parameters are proven to reflect the temperature effect of materials with significant physical implications, which have also been discussed under various boundary conditions, e.g., temperature and cooling. The proposed 3-D temperature-dependent thermal model has been validated through FEM simulation and experiments, which shows satisfying performance in predicting the thermal behaviors under the whole-temperature conditions with an error within 1.2%.