Assessment of crawling of an induction motor by stator current Concordia analysis

Proposed is a method of diagnosis of crawling of an induction motor by stator current Concordia analysis. It has been done by assessing generated harmonics using stator current Concordia. Stator current of an induction motor has been captured, normalised and then Concordia has been formed in the Park plane. The presence of different harmonics has been assessed by a rule set based on the features extracted from the patterns developed by stator currents. Dominance of seventh harmonics is determined which is the main cause of crawling without using any filter or any Fourier or wavelet transform based technique. This method has been validated by a laboratory prototype.