Research on the Amplitude Features of Stator Current for Motor with Bearing Faults

Abstract

Martin Blödt first introduced that the modulation mode between fundamental frequency of rotor vibration, which is caused by bearing faults, and fundamental frequency of stator current is phase modulation. This paper accomplished the theoretical derivation about the impact of bearing fault on stator current based on torque vibration harmonics, and gave the amplitude expression of stator current fault-related frequencies. The bearing fault simulation device which could simulate singlepoint defect was established. The effect of torque vibration harmonics on stator current amplitude was verified by simulation and experimental research. The obtained results showed that the amplitude features of stator current are not only related to the fault severity but also related to the size of the fault zone.