Stator current harmonics and their causal vibrations: A preliminary investigation of sensorless vibration monitoring applications

This paper presents an initial study into the relationship between vibratio n end current harmonics of electric motors, including the effect of externa lly induced vibrations. This relationship was investigated experimentally o n both new motors, on a vibration stand, and a motor with bearing wear, Bot h theory and experimental results show that a change in the rms value of th e stator current is directly related to the change in vibration magnitude, for a known vibration frequency. The paper shows this result both for a new motor with an externally induced vibration and for a motor with vibration caused by progressive bearing wear.