A 3-D Electromagnetic Thermal Coupled Analysis of Permanent Magnet Brushless DC Motor

In recent years, with permanent magnetic materials and motor manufacturing technique progressing, permanent magnet brushless DC motor power density enhances unceasingly. This means that the electromagnetic loads of the motor are continuously increasing, and the heat load is soaring. The motor thermal design is becoming more and more important. The thermal design is a complex problem of electromagnetic field and thermal field coupled. This paper proposes a new method of electromagnetic and thermal coupling analysis by calculating both the electromagnetic field and temperature field in motor. Simulation results and test data verify the rationality of the motor temperature field model and the accuracy of the calculation. Furthermore, the motor temperature field is analyzed at different ambient temperature and different ambient air velocity based on the method. This new analysis method proposed would be helpful for the optimization design of the motor.