Electromagnetic-thermal coupling applied to the analysis of the heat transfer in a traction motor

The paper is aimed at the coupling between the electromagnetic and thermal physical phenomena, applied to the investigation and analysis of the heat transfer in a typical traction motor. To start with, the heat transfer basis are recalled with emphasis on the convection phenomenon. A thermal-electrical analogy is established for the sake of an analytical investigation of the heat transfer in the stator of the studied traction motor. Such an investigation is extended to a FEA-based modelling of the heat transfer of the machine. Prior to do so, the machine Joule and iron losses are predicted. Then, an electromagnetic-thermal coupling is established where these losses behave as heat sources. The FEA results reveal high temperatures in different areas of the machine especially in the stator slots. Two cooling approaches are investigated, which are: (i) forced air in the rotor pockets, and (ii) a water-filled spiral tube mounted around the outer surface of the stator.