Concordia transform-based current analysis for induction motor diagnosis

This paper presents a new approach to bearing defect diagnosis in induction motors, based on the Concordia transform of the three-phase stator current signals. Specifically, Concordia transform is firstly performed on the real-valued three-phase motor current signals to construct complex-valued signals. The instantaneous frequencies of the current signals are then extracted through a phase demodulation. Subsequently, spectral analysis is performed on the current instantaneous frequencies to identify bearing defect features. Both simulation and experimental studies are performed to demonstrate the effectiveness of proposed method in identifying bearing defects. The method is inherently low cost, non-invasive, and computational efficient, making it a good candidate for various applications.