Analysis and Reduction of Electromagnetic Force Waves of Permanent Magnet Synchronous Motors Considering Rotor Eccentricity

The accurate calculation and reduction of electromagnetic force waves are important prerequisite for the evaluation and optimization of electromagnetic vibration. In this paper, an accurate calculation method of air gap permeance is proposed, the air gap flux density and the resulting electromagnetic force waves of 6p36s surface-mounted permanent magnet synchronous motor considering the rotor eccentricity are analyzed and calculated. Furthermore, the components of air gap flux density and electromagnetic force waves under rotor eccentricity with three different windings connection modes at rated load are compared. The results indicate that the components of electromagnetic force waves introduced by rotor eccentricity can be effectively weakened by adopting appropriate windings connection modes without affecting the basic performance of the motor, and the windings connection mode in which the adjacent coils of each phase constitute parallel branches with equalizing lines has the best weakening effect.