Current-based algorithm for mechanical fault detection in induction motors with arbitrary load conditions

Mechanical faults in induction motors can be detected by monitoring specific components in the stator current frequency spectrum. Previous work tested some mechanical conditions for the cases of no-load and full-load conditions in small induction motors, assuming that the effect of load on the detection scheme between these two conditions is linear. This paper presents an algorithm for detecting mechanical conditions in induction motors under any load condition using spectral analysis of the stator current. The proposed algorithm takes into account the load related abnormalities and resonance by classifying the load-levels into bins and calculating a baseline for each load bin.