Application of a wavelet-based MRA for diagnosing disturbances in a three-phase induction motor

This paper presents a new technique for detecting and diagnosing various disturbances occurring in three-phase induction motors. The proposed technique is based on a wavelet-based multiresolution analysis (MRA), where samples of three-phase stator current are analyzed using wavelet-based MRA. Different disturbances have been created in both stator and rotor windings of a wound rotor induction motor. Stator currents data have been collected for processing using a wavelet-based MRA. The application of the wavelet packet transform has shown that all fault conditions have non-zero second level high frequency subband coefficients, while normal and starting currents have zero values for the same coefficients. This property can be used as a main diagnosis tool for induction machine protection.