A Spectrum Synch Technique for Induction Motor Health Condition Monitoring

Induction motors (IMs) are commonly used in various industrial applications. A spectrum synch (SS) technique is proposed in this paper for early IM defect detection using electric current signals; fault detection in this paper will focus on defects in rolling element bearings and rotor bars, which together account for more than half of IM imperfections. In bearing fault detection, the proposed SS technique will highlight the peakedness of the fault frequency components distributed over several fault-related local bands. These bands are synchronized to form a fault information spectrum to accentuate fault features. A central kurtosis indicator is proposed to extract representative features from the fault information spectrum and formulates a fault index for incipient IM fault diagnosis. The effectiveness of the developed SS technique is demonstrated on IM with broken rotor bars and IM with damaged bearing. Test results show that the developed SS technique can detect incipient IM faults effectively.