Analysis of airgap flux, current and vibration signals as a function of the combination of static and dynamic airgap eccentricity in 3-phase induction motors

Abstract

This paper provides new information for the online diagnosis of airgap eccentricity in three-phase induction motors. A new theoretical analysis of the interaction between harmonic field components due to static and dynamic rotor eccentricity which previous research has not considered is put forward. The resultant harmonic current components produced in the supply current which are highlighted by the analysis are found to exist experimentally and indeed shown to be a function of the combined effect of both dynamic and static eccentricity. Further vibration analysis is put forward to identify which particular form of rotor eccentricity is dominant; hence illustrating how faults can be identified in a motor using condition monitoring techniques.