Experimental comparison between diagnostic indicators for bearing fault detection in synchronous machine by spectral Kurtosis and energy analysis

In this paper, some indicators are developed for efficient detection of bearing defaults in high speed synchronous machines. These indicators are based on the analysis of stator current. As bearing defect signatures can be tracked through amplitude increase of some current harmonics, two specific indicators have been built based on energy considerations and on the Spectral Kurtosis analysis. These indicators are tested on a real industrial fan equipped with ceramic balls, in its environment. Several measurements for different operating points are tested to validate the approach and to its robustness during long time tests. From an experimental comparison between a healthy fan and another with damaged bearings, a frequency selection is performed to identify the frequency ranges where the energy is the most sensitive to the considered faults. This actuator is used in an air conditioning fan in aeronautic applications.