Detection of mixed air gap eccentricity in closed-loop drive-connected induction motors

This paper focuses on the detection of mixed air gap eccentricity in closed-loop drive-connected induction motors. The influence of speed and current PI controllers on the fault detection is considered together with the load oscillation. For high detection sensitivity and accuracy, this paper points out that the monitoring of low frequency harmonics in the stator voltage and high frequency harmonics in the stator current in suitable reference frame should lie combined together. The simulation and experimental results are included to verify the feasibility of the proposed detection scheme.