Thermal Analysis of a High Speed Permanent Magnet Synchronous Motor

The power density of high-speed permanent magnet motors is high, but the heat generation is severe. In order to reduce losses of the target motor in this study to ensure that permanent magnets and insulation materials work at safe temperature, this study compares different materials for sheath. On the basis of the simulation result of wind friction loss, the results are compared when using different empirical formula for friction coefficient. Based on the analysis of losses, two motor cooling structures including an axial channel considering the motor structure are designed and compared. To get more accurate simulation results, coupling of the electromagnetic field and the thermal field are studied. Results show that both schemes meet the requirements for operating temperature, and the effect of the axial waterway is better.