Impact of eccentricity and demagnetization faults on magnetic noisegeneration in brushless permanent magnet DC motors

Abstract

Vibrations and noise in electrical machines are directly related to the characteristics of theradial forces on one hand, and mechanical behavior on the other [1, 4]. The characteristics of theseforces depend on the air gap flux density, which is also influenced by other factors, such as stator slotsand poles, saturation level, winding type, and certain faults. The aim of this work is to investigate theeffect of eccentricity and demagnetization faults on electromagnetic noise generated by the externalsurface of Permanent Magnet Synchronous Machine [PMSM]. For this purpose, an analytical electromagneticvibroacoustic model is developed. The results confirm the effect of eccentricity and demagnetizationfault in generating some low modes radial forces.