Coupled 3-D Thermal and Electromagnetic Modelling of a Liquid-Cooled IPM Traction Motor

Modelling of electrical machines is constantly refined and it is now possible to couple CFD thermal models with FEM electromagnetic models, thereby considering the thermal effects on motor materials. Usually, the models are made as small as possible in order to reduce calculation time and computer resources. However, in this paper it is shown how to model an interior permanent magnet (IPM) motor in 3-D so to be able to include magnet, core and copper loss (including losses in the end windings) and the effect of air and liquid cooling. It is shown that the simulation results agree fairly well with referenced measurements. Further, it is shown how the liquid cooling input temperature affects the efficiency for a set of load points within the torque-speed range of the motor.