Thermal field analysis and optimization of the U-core permanent-magnet motor

U-core permanent-magnet motors, which are the core component of small-sized water pnmps, have high temperature rise because of their small size and concentrated heat source. This will not only affect the performance of the motor, but also cause the motor to burn out in severe cases. Therefore, it is necessary to study the thermal field of the U-core permanent-magnet motor. This paper uses the finite element software MAXWELL to calculate the loss of the motor. At the same time, the surface heat transfer coefficients of each boundary surface are calculated using an empirical formula method and an iterative method. Based on this, the finite element software ANSYS is used to calculate the motor thermal field, and a multilayer square-ring equivalent winding model is established based on the source of the calculation error to improve the calculation accuracy of the thermal field. The optimization schemes are proposed and compared for the place where the temperature rise of the motor is highest. This paper selects a reasonable optimization scheme from the temperature rise reduction ratio, lifespan, implementability and cost to provide the basis for the design and optimization of the thermal field of this type of motors.