Numerical Study of the Thermal Resistances Calculation Influence on the Thermal State of an Electric Motor

In this paper, the influence exerted on the thermal state of a brushless DC motor is numerically investigated by the methods used to calculate contact thermal resistances that differ from the principles laid down in them. The impact assessment was carried out using a three-dimensional numerical simulation of the operating electric motor coupled heat exchange with the environment in the special software package. The electromagnetic calculation carried out for calculating engine losses is validated to verify the adequacy of the calculated heat sources power values set in the CFD calculations. The results of two calculations that differ in the applied methods for determining thermal resistances are compared.