Detection of eccentricity fault using slot leakage flux monitoring

Abstract

Eccentricity is a common fault in the running of electrical machines. Aimed at the problem, a new approach to detect eccentricity fault is presented by monitoring the slot leakage flux of stator in this paper. In order to measure the slot leakage flux, two placements of search coil in the stator slot are applied. Firstly, the theoretical analysis shows the slot leakage flux contains more information about eccentricity fault than the stator current does. Then the submersible motor as a model, the induced voltages of search coil and the stator currents are obtained by finite element simulation under healthy motor, static, dynamic and mixed eccentricity, respectively. And various analysis and comparisons of simulations are made. The results show that monitoring the slot leakage flux is effective and has more advantages than the motor current signature analysis. Index Terms--Eccentricity, search coil, slot leakage flux, submersible motor.

Higher-Order Spectral Analysis of Stray Flux Signals for Faults Detection in Induction Motors

“…However, they can be observed in stator current only under mixed eccentricity. Moreover, detection of dynamic eccentricity in stator current around the principal slot harmonic (PSH) is only useful for some combination of pole pairs and rotor slots [53,61,62]. Under mixed eccentricity conditions, the stator currents contain the following frequencies [47]:…”