Fault diagnosis in induction motors using radial magnetic field measurement with an antenna

In this paper the emf induced in a search coil is measured in order to detect faults in an induction motor. Anomalous operations caused by a broken rotor bar or a faulty stator cutting phase are analysed. Starting from a theoretical analysis of the radial field spectrum associated with these faults, the measurement of the corresponding emf in the search antenna is examined. The saturation and harmonic components of the permeance produced by the slotting effect are taken into account. Their interactions are analysed, allowing the identification of the frequencies which are of interest for the detection of stator cutting phase faults in a working induction motor.