Research on Influence of Rotor Eccentricity on Electromagnetic Vibration in High-speed Permanent Magnet Generators

Rotor eccentricity faults can cause uneven air gaps in the motor, reducing electromagnetic performance of the motor and increasing vibration noise, which eventually leads to the motor not operating properly, especially in high-speed motors, where the damage will be more serious.In this paper, the effect of static and dynamic eccentricity faults on the electromagnetic vibration of high-speed motors is studied using a back-wound high-speed permanent magnet generator (HSPMG) as an example. Firstly, an eccentricity mathematical model is established and the electromagnetic characteristics of static and dynamic eccentricity are analyzed using the numerical calculation method. The spatial and temporal distribution of the air gap magnetic field under the fault is obtained, revealing the change mechanism of the magnetic field asymmetry after the eccentricity fault. Secondly, based on Fourier time-harmonic analysis, the characteristic parameters of the electromagnetic force wave under different eccentricity rates are studied, and the characteristic parameters of the introduced electromagnetic force wave components after the eccentricity fault are obtained. Finally, the vibration acceleration of the generator stator is obtained by multi-physics field coupling and harmonic response analysis, and the vibration characteristics of the stator under static and dynamic eccentricity faults are determined to provide reference for the diagnosis and identification of eccentricity faults in high-speed motors.