Laboratoire Systèmes Électrotechniques et Environnement, Université d'Artois, Faculté des Sciences Appliquées, Technoparc Futura, 62400 Béthune, France
This paper presents a method for detecting faults in the induction machine using a flux sensor which measures the external radial leakage magnetic field of the machine. The procedure uses the spectral lines that correspond to the slotting effect which causes harmonics in the machine air gap. These harmonic frequencies, which are about a few kHz occur in a part of the spectra which is not very dense compared to the one that corresponds to the low frequencies due to the supply or the rotor revolution speed. The considered components can also be detected in the radial magnetic field flowing out of the machine. It can be shown that specific faults lead to additional spectral lines which appear clearly near the original ones due to the slotting effect. Two faults, which can be detected with the same magnetic flux sensor, are presented in this paper: the first one corresponds to a broken rotor bar, the second one is a stator inter turn short circuit.
(Received February 25 2003)
(Revised July 5 2005)
(Accepted July 19 2005)
(Online publication October 26 2005)