Investigation of Multiple Faults Detection in Electric Machine Using Broken Rotor Bar and Eccentricity Fault Frequencies Techniques

The aim of this paper is to investigate and detect the multiple faults in machines using broken rotor bar and eccentricity fault frequencies techniques. It is proposed that using both current and instantaneous power signals simultaneously, will detect the multiple faults reliably, specifically using broken rotor bar fault frequencies and eccentricity fault frequencies under various load conditions. The analyses carried out in this paper show that the current spectra is able to detect multiple faults i.e. a combination of broken rotor bars and eccentricity faults either by using broken rotor bars fault frequency components (1±2s)f1 or using eccentricity fault frequency components (f1±fr) at any levels of loading. The results from the instantaneous power spectra using modified broken rotor bar fault frequency components (fp±4f2) show that it is preferable for estimating either the machines having multiple faults. It can be concluded from the results that flux signal is also not a useful source to detect multiple faults using both broken rotor bar and eccentricity fault frequency components.