Analysis of radial electromagnetic force under different poles/slots matched in large torque PMSMs

Vibration and noise reduction is one of the most important requirements in the design of PMSM due to its direct impact on service life and operating stability. The radial electromagnetic force acted on the rotor is a major factor of a PMSM influencing on its vibration and noise. In this paper, the distribution characteristics of radial electromagnetic force were theoretically analyzed on the basis of FEM method in Ansoft, simulation analysis of radial electromagnetic force corresponding to different slot/pole structures was carried out, and test of direct-driven large torque PMSMs was presented to validate the theoretical analysis. The conclusion has a good meaning to optimum design of these motors.