Zeng Jinling, Wang Jinhao, Sun Xiaoji
Motor System Development Section, Electric Vehicle Department, CHINA FAW CORPORATION LIMITED R&D CENTER

Abstract

Overheating in E-motor results in detrimental effects such as degradation of the insulation materials, magnet demagnetization, decreased motor efficiency and lifetime. Hence, it is important to find ways of optimizing performance and reliability of E-motor through effective thermal simulation and consequently reduce operating and maintenance costs. Modern thermal simulation techniques can be classified into two general methods, thermal circuit and FEM method. But because the 3D FEM method can more accurately predict and identify the temperatures of the critical points of the motor, it is more effectively than the thermal circuit method to evaluate the E-motor temperature rise. This paper describes a 3D thermal methodology for a permanent magnet synchronous motor by coupling 2D electromagnetic losses analysis with 3D thermal simulation. The energy sources are obtained from electromagnetic losses simulation by using JMAG. Coupling the loss results, the 3D nonlinear thermal model provided the detailed temperature distribution and rising results in E-motor assembly. Finally, a bench test was done to evaluate the FEM result, 3D thermal simulation results show good agreement with experimental results.