Experimental investigation of on-line methods for incipient fault detection [in induction motors]

Condition-based maintenance (CBM) of industrial equipment is generally recognized as being the most cost-effective means for improving equipment availability. However, prerequisite to successful implementation of CBM is a reliable detector of failing components. One such detector, termed the effective negative-sequence impedance, had previously been identified as an indicator of induction motor stator winding degradation. However, a limitation of this detector is that it does not change in a predictable manner under certain motor operating conditions. This paper presents an experimental investigation of an improved technique for online detection of induction motor stator winding degradation. The paper begins with a brief description of the detectors, followed by a detailed description of the experimental setup, the experiments conducted and results.