Study of incipient bearing damage monitoring in variable-speed drive systems

Inverter-induced high-frequency bearing currents are a common root cause of bearing failures in frequency converter-fed motors and generators. Bearing faults are typically identified by vibration measurements. In our work, we experimentally submit bearings to electric discharge machining (EDM) bearing currents, use different means to measure the electrical stress placed on the bearings, measure the resulting vibration signal, and apply signal processing for feature extraction. All this is done 1184 hours of operation, so as to study the incipient bearing failure behavior.