Fault Eccentricity Diagnosis in Variable Speed Induction Motor Drive Using DWT

This paper describes the monitoring and diagnosis of eccentricity fault in variable speed induction motor drive. The used control technique is the indirect field oriented control (IFOC) fuzzy logic based controller to ensure the robust speed regulation and to compensate the fault effects. The variable speed induction motor can be affected by various kinds of faults. Airgap eccentricity is one of the major defects occurring in such electric drives; its detection could be useful for preventing potential catastrophic failures. A dynamic model taking into account the faults is proposed based on the approach of magnetically coupled coils to simulate the behavior of eccentricity faults in induction motor. This work presents two approaches for diagnosis and detection of eccentricity faults and evaluation of their severity based on monitoring of the stator current signals, using Park vector method and discrete wavelet transform (DWT) with different approaches to distinguish healthy as well as faulty conditions of the machine. The obtained simulation results via the proposed technique allow detection and diagnosis of eccentricity fault and identify their severity.