Modeling and Detection of Eccentricity and Demagnetization Faults in Brushless Permanent Magnet DC Motors by Vibroacoustic Behavior

Abstract

Vibrations and noise in electrical machines are directly related to the characteristics of the radial forces on one hand, and mechanical behavior on the other [1,8]. The characteristics of these forces depend on the air gap flux density, and they are influenced by other factors such as stator slots and poles, saturation level, winding type and certain faults. The aim of this work is to investigate the effect of eccentricity and demagnetization faults on electromagnetic noise generated by the external surface of PM synchronous machine. For this purpose an analytical electromagnetic vibroacoustic model is developed. Many parts of the analytical model are validated using FEM simulations. The results confirm the effect of eccentricity and demagnetization fault in generating some low modes radial forces.