Reliable Detection of Very Low Severity Level Stator Inter-Turn Faults in Induction Motors

Stator electrical faults are considered the most severe and challenging to detect among the various induction motor faults. This is due to the fast evolving severity level that leads from an early inter-turn fault to the machine breakdown. Many works have been published over the years presenting a variety of diagnostic techniques to detect this fault. However, the fault level severity is kept high enough to allow for the diagnosis neglecting the fact that at that severity level the machine will fail and thus diagnosis of the fault is useless. This paper challenges the existing technical know-how in the subject, while attempting to detect the fault at very low severity levels. It will be shown with extensive experimental testing and analysis that many well established methods are completely unreliable for this task. Finally, the authors propose a novel method that is able not only to detect the fault reliably but is also sensitive to the fault level severity.