Vibration-Based Identification of Mechanical Defects in Induction Motor-driven Systems During the Starting Transient

Vibration analysis is the most widely applied method for detecting mechanical faults such as load unbalance, misalignment, and looseness in induction motor driven systems. Most mechanical problems result in an increase in vibration at the rotor frequency (1x) making it difficult to identify the source of vibration for planning maintenance action. If the vibration level is excessive, a walk-around test is usually performed by the maintenance engineer to identify the source of vibration, exposing the maintenance personnel to safety risks. In this paper, a new remote, automated method for identifying the source of vibration during the starting transient of induction motors is proposed. The level and speed-dependency of vibration during rotor acceleration are used for identifying the cause of vibration. Experimental results on an induction motor under emulated mechanical defects are given to show the remote and automated capability of the proposed method for safe, low cost, and efficient maintenance.