A frequency-domain detection of stator winding faults in induction machines using an external flux sensor

The aim of this paper is to present the advantage of stator fault detection using an external stray flux sensor in a working induction machine. In the past 20 years, stray flux sensors have been used for diagnostic purposes but rarely in the presence of a complex power supply such as a voltage static inverter. In this paper, it is proved that a simple external stray flux sensor is more efficient than the classical stator current signature analysis to detect inter-turn short circuit in three-phase induction machines. The new result is that, even in the presence of power supply harmonics, it is possible to easily detect the stator winding faults in the low-frequency range of the flux spectrum with low-frequency resolution.