Modulated Vibration Reduction Design for Integral-Slot Interior Permanent Magnet Synchronous Machines

In this article, a targeted step skewing of rotor segments scheme is proposed to reveal the modulated vibration reduction mechanism in integral-slot interior permanent magnet synchronous machines (IPMSMs). First, the vibration characteristics of a 72-slot/12-pole integral-slot IPMSM are investigated. The dominant vibration at specific frequency band is introduced. Then, in order to analyze the main source of vibration, the magnetic field modulation effect and radial force modulation effect are investigated in detail. The results show that the high-order radial force can excite large vibration by radial force modulation effect. This kind of vibration is defined as modulated vibration. Afterwards, the optimal shift angle and number of rotor segments are determined by comparison. Finally, the conventional and proposed 72-slot/12-pole integral-slot IPMSMs are manufactured to validate the theoretical analysis. The experimental results verify that the proposed method can effectively reduce the modulated vibration of the 72-slot/12-pole integral-slot IPMSM.