Thermal 3D Modeling and Analysis of PMSMs with Inter-Turn Faults

Intern-turn faults are one of the most common causes of machine failure. The propagation of this fault is mainly determined by the local fault temperature. In this paper, we present a 3D analytical approach to determine the temperature distribution inside the windings during an inter-turn fault. To do so, a coupled electromagnetic-thermal model is used. The fault loss is calculated in the electromagnetic model and serves as an input for the thermal model. The thermal model consists of an extended layer approach, which we adapted to simulate inter-turn faults. It can be seen that the fault's location and the fault area have a major influence on the maximum temperature rise. For a fault in the active region close to the stator yoke the maximum temperature rises for a fault loss of 10 W by 8.8 K, whereas the maximum temperature rises by 137.6 K in the middle of the end winding. The maximum temperature rise is highly dependent on the fault's location and the maximum temperature rise increases, the closer to the air gap the fault occurs. The closer it is in axial direction to the middle of the end windings, the larger the maximum temperature rise.