Asymmetrical Fault Detection in Induction Motors Through Elimination of Load Torque Oscillations Effects in the Slight Speed Variations and Steady-State Conditions

Recently, motor current signature analysis has been widely considered for fault detections due to its simplicity, availability, and cost-effectiveness. The rotor asymmetry (RAF) is the most common that occurs in induction machines. It extremely challenging detect RAF indices occurred at vicinity of supply frequency. Moreover, load torque oscillations (LTOs), which appear as a sinusoidal phase modulation frequency, exhibit similar indications RAF, especially gearbox-based electromechanical systems. Since LTOs lead false alarm separation from characteristic components inevitable. In this article, normalized frequency domain energy operator (NFDEO) evaluated demodulation steady-state transient conditions. proposed method tested both with-and-without speed control strategies. regard, effects presence investigated through synthetic signals experimental data conditions with slight variation speed. obtained results show NFDEO along Winger–Ville can effectively even strategy.