Research on Fault Diagnosis Method Based on Probe Coil for Inter-Turn Short Circuit and Rotor Eccentricity

Inter-turn short - circuit faults, permanent magnets demagnetization faults, and rotor eccentricity faults are common motor faults that can lead to severe consequences. Traditional analysis methods based on current signal characteristics are easily disturbed by factors such as changes in motor operating conditions and inherent asymmetry. Moreover, the characteristic overlap in multi - fault representations result in low fault recognition accuracy and resolution. To address these issues, a novel 8-shaped detection coil is proposed. By leveraging the imbalance in the electromagnetic field distribution within the motor under fault conditions, this coil enables highly robust and accurate detection of early - stage inter - turn short - circuit faults, permanent magnet demagnetization faults, and rotor eccentricity faults. The time - domain and frequency - domain characteristics of the terminal voltage of the detection coil under inter - turn short - circuit faults are studied. Additionally, the detection mechanisms for rotor eccentricity faults and permanent magnet demagnetization faults are analyzed.