Zeroth-Mode Vibration Suppression for Integral-Slot Surface-Mounted PMSMs by Increasing the Vibration Mode From Zero to Number of Pole Pair

Zeroth-mode vibration is the main electromagnetic (EM) vibration component in integral-slot permanent magnet synchronous machines (PMSMs). This article proposes a new method for integral-slot surface-mounted PMSMs to suppress the zeroth-mode vibration by increasing the vibration mode from zero to the pole pair number. The proposed method involves designing two different permanent magnet (PM) shapes, respectively, for the N and S poles to make the specified EM force harmonics under adjacent poles equal in amplitude and opposite in phase. In this article, the EM vibration was analyzed based on the modulation effect of the slotted structure and the theorem of translation of a force. The relationship between the vibration mode and the EM force harmonics has been summed up. Based on this, the proposed method was expounded, and a 10-pole/30-slot surface-mounted PMSM was taken as an instance to demonstrate the process of the proposed method. Three prototypes with different rotors were simulated and measured to validate the proposed method. The results have proved the effectiveness of the proposed method.