Analytical Calculation of Magnetic Field and Temperature Field of Surface Mounted Permanent Magnet Synchronous Motor

In this paper, a hybrid analytical method based on subdomain method and magnetoresistance network method is proposed. This method combines the advantage that the subdomain method is relatively accurate in calculating the magnetic field of the motor and the advantage that the magnetoresistance network method can consider the saturation effect of ferromagnetic materials. It can calculate the rated-load air gap magnetic flux density of the motor relatively accurately. Then, the heat source in the T-type equivalent thermal network model is obtained by solving the loss model. On this basis, the temperature field of the motor is calculated relatively accurately by considering the gas exchange in the motor caused by rotor rotation through parameter identification of the air gap thermal resistance. Compared with the subdomain method, the hybrid analytical method can consider the saturation effect of ferromagnetic materials. Compared with the existing T-type equivalent thermal network method, the improved T-type equivalent thermal network method can consider the gas exchange caused by the rotation of the motor rotor. The accuracy of analytical calculation of magnetic field and temperature field of motor can be improved by these two improvements. Finally, the validity of the method is verified by finite element analysis and experiment.