Thermal Analysis of Permanent Magnet Synchronous Motor Based on Equivalent Thermal Network Method

Nowadays the permanent magnet synchronous motor (PMSM) is extensively applied in ship propulsion systems and other applications because of its advantages of energy savings, high efficiency, and high power density. The temperature rise is necessary to be considered in the preliminary design and the parameter optimization of PMSMs, thus the thermal analysis of the PMSM is significant. In this paper, an equivalent thermal network (ETN) model of a surface-mounted PMSM is proposed to predict the temperature rise. The thermal resistances and heat sources of the motor are estimated and examined, and the thermal balance equation is introduced and solved. The temperature rise and average temperature of each node are calculated, and the model's accuracy is validated using finite-element analysis (FEA) and experiments. The results demonstrate that the ETN method which offers an effective thermal analysis approach for PMSMs can reduce analysis time compared to the FEA method while retaining a certain level of accuracy.