Thermal Concept Design of MOSFET Power Modules in Inverter Subsystems for Electric Vehicles

The most important key in the thermal management of power electronic devices is the cooling system design. One of the most promising cooling techniques is indirect liquid cooling using cold plates. This paper studies the performance of a liquid cooling system on the junction temperature of a high-power inverter drive utilizing three legs of half-bridge modules (CAS120M12BM2 Silicon Carbide CREE MOSFET). One of the primary objectives is to compare the effect of different geometries and boundary conditions on the thermal performances regarded as maximum junction temperature. Based on the analysis of the liquid cooling, different boundary conditions are proposed and a comparison of the main case study is made against the case of different geometries and boundary conditions. Furthermore, the concept of varying the distance between three half-bridge MOSFETs in an inverter drive is introduced. According to the simulation results, in the best combination, the maximum junction temperature of the module is decreased to 82.2 degrees C when the thermal paste and NX100 materials are selected for the thermal interface material and the heat sink, respectively. In addition, Simulation results show that the best distance between each of the modules in the inverter drive is 10mm spacing.