Investigation into effect of mixed air gap eccentricity on an injected component in acquired current signal in induction motor

The Fourier transform is the commonly used method for the diagnosis of fault signatures in induction machines by analyzing the measured signatures such as stator currents, neutral voltage, power … It provides accurate results that are directly related to the acquisition frequency and time of the captured signal. For online monitoring, we are usually dealing with window side lobes leakage phenomenon in the spectral analysis caused by the limited time signal acquisition and analysis. These lobes are widely considered as an undesirable phenomenon because they blur the frequency spectrum. However, we have shown [1] that these lobes can carry fault signatures with the advantage of reducing the computation time and making online diagnosis possible. Using this method, this paper focuses on the online diagnosis possibilities of the mixed air gap eccentricity in the induction machine. Analytical studies and experimental results are conducted to demonstrate the effectiveness of the proposed method.