Electromagnetic and Direct-cooling Analysis of a Traction Motor

The trend is to compact powertrains to lower their cost, hence size impacting their multi-domain performance. In-wheel traction motors are more susceptible owing to the stringent volume and mass constraints. This paper analyzes the electromagnetic and the CFD cooling performance of a permanent magnet axial-flux traction motor. Therefore, speed-dependent electromagnetic losses are necessary for accurate thermal loads. Instead of the whole speed range, it is shown that two operating points are sufficient to characterize the motor cooling performance. Further reduction of CFD-thermal solving time is gained by leveraging the motor topology and the fast steady flow solver. As a result, three direct-cooling designs are analyzed. The teeth-wound stator coils ease the implementation of direct-cooling; permitting higher current-densities. To safeguard against permanent magnet degradation, segmentation and demagnetization analysis are included in electromagnetic analysis. Consequently, it is possible to ensure a motor’s availability irrespective of the drive-cycle, driver-behavior, and ambient conditions.