Time-domain bearing condition monitoring in induction motors using instantaneous frequency of motor voltage

Bearings are important components in induction motors. Bearing failures are actually the most frequent failures in this type of machines. Utilizing electrical signals and eliminating signals such as vibration is essential to reduce the cost of condition monitoring schemes of electrical machines in industry. In this paper, the instantaneous frequency of motor voltage is introduced to monitor bearings condition. By using this signal, for instance, the global kurtosis and crest factor are able to detect bearing defects in time-domain. In this work, envelope analysis of vibration signal is used to verify the existence of bearing defects. Experimental results show the effectiveness of the proposed bearing condition monitoring method.