On the role of the shaft end in the radio-frequency emission of discharge bearing currents in induction motors

A novel non-intrusive radio-frequency-based method to detect discharge bearings currents occurring in variable speed drives had been presented previously. Further understanding of the emission characteristics of the discharge and of the electric machine it occurs in will widen its areas of application. To this aim, this paper addresses the modeling of the machine as an antenna, identifying the shaft ends to play a key role. Additionally, a first set of results on the use of location techniques to locate the discharge incident are presented.