Mechanical fault diagnosis of outdoor high‐voltage disconnector

A series of experiments are conducted on a 252-kV pantograph disconnector offline to monitor its mechanical condition. Three parameters, namely the dynamic strain of the post insulator, the rotation angle of the operating shaft, and the stator current of the driving motor, are measured by resistance strain gauges, magnetic-sensing angle transducer, and Hall current sensor, respectively. Measurement results of the three parameters under mechanical fault conditions including clamping stagnation of the conduct tube knuckle, failure of the balance spring, and uncompleted closing operation are compared with those in normal operating condition of the disconnector. The results indicate that the dynamic strain waveform, the rotation angle curve, and the motor current envelope waveform may get distorted with increased peak value and offset peak time when mechanical faults happen to the transmission or rotating mechanism of the disconnector, and more component of the side frequency will appear in the spectrum of the motor current waveform. The proposed methods are validated to be effective for mechanical fault diagnosis and condition assessment of pantograph disconnector, and are also of reference significance for other types of disconnectors. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.