An Enhanced Bispectrum Technique With Auxiliary Frequency Injection for Induction Motor Health Condition Monitoring

Induction motors (IMs) are widely used in various domestic and industrial applications. A reliable IM health condition monitoring system is very useful to detect IM fault at its incipient stage to prevent performance degradation of IMs and their driven equipment. An enhanced bispectrum (EB) technique with auxiliary frequency (AF) injection (EB-AF) is proposed in this paper to conduct incipient IM fault detection. The AFs are injected into the electric current signals to enhance fault characteristic frequency components. The EB technique transforms the traditional 2-D bispectrum with massive features into a one-scale spectral representation to facilitate feature extraction for IM defect detection. The effectiveness of the developed EB-AF technique is examined by IM bearing fault detection with different speed and load conditions. Test results show that the developed EB-AF technique can reveal fault features effectively for initial IM fault detection.