[2B4] Failure mode and slip frequency analysis in induction motors
S Ganeriwala
Spectra Quest Inc, USA
Diagnostics of an induction motor is a serious issue for improving plant reliability. Motor current signature analysis (MCSA) and vibration data are commonly used for diagnosing induction motor problems. This paper will present a comparison of vibration and motor current signals for an induction motor subjected to different fault types and understand the underlying physics of rotor slip. We will describe the mechanism of torque and associated current fluctuation. This fluctuation generates secondary current at twice the rotor slip with respect to the line frequency. Results of experiments performed on intentionally faulted induction motors will be presented and discussed. The data was analysed using both vibration and motor current sensors. The results suggest that both motor current and vibration measurements are required for more complete diagnostics of induction motors.
