Novel noise improvement technique for a PMSM with concentrated winding

The vibration of concentrated winding motors tends to be higher than distributed winding motors. This phenomenon is caused by the projection of radial stress. Hence, an effort has been made to reduce the vibration of the concentrated winding motors considering its radial stress. In this paper, it is shown that for the concentrated winding motors the radial stress becomes partly large which leads to deformation of the stator core. Therefore, the air gap length where radial force is large has been enlarged. It has been found that the radial stress in the air gap becomes smooth by enlarging the air gap partly and consequently, the vibration of the motors can also be reduced.