A comparison of rotor fault detection techniques with respect to the assessment of fault severity

This contribution compares rotor fault detection techniques of squirrel cage induction machines such as motor current signature analysis, Park's vector, motor power, torque, search coils, vibrations and acoustic emissions. Innumerable papers have been published about those techniques so far. Yet, the assessment of the severity of the actual fault has not received much attention. The term severity refers to the grade of electrical asymmetry of the rotor. This paper examines fault assessment and the respective specification. The objective is to compare those rotor fault assessment techniques which reflect the state of the art. A wide range of literature is cited in order to provide appropriate references. The authors also present and compare some measuring results in order to illustrate the investigated techniques.