Electrical signals analysis of an asynchronous motor for bearing fault detection

We present in this paper the detection of a rolling defect in an asynchronous machine by analysis of the electric signals. For this purpose, we used a Wiener filter to decrease the dynamics of the 50 Hz and to increase the frequencies associated to the mechanical load. Thus, we could detect the presence of a ball defect. This result is corroborated by an envelope analysis of the vibratory signals. The suggested method exploits the cyclostationarity of electrical signals (voltage and current) via their cyclic statistics to resynchronize the signals according to the electrical cycle (50 Hz) in order to recover frequency fluctuations. We then estimate the Wiener filter which is highly adapted to our application in order to obtain a signal corresponding to the electrical part only, which allows extracting the mechanical part on the measured current. An experimental result, in the presence of fault in rolling element bearings, illustrates the high performance of the proposed method