A 330kV substation in Shaanxi: the abnormal vibration of the A phase knife gate in the 330k substation of this station has been detected by a variety of technical means, and there are no anomalies detected by the SF6 decomposition and the ultra high frequency (UHF) detection. The detection system developed by the research team found that the location had obvious vibration signals and showed the characteristics of external fastener loosening. The field analysis and inspection of the joint repair company and the switch manufacturer found that the bolt loosened on one side of the A phase switch, and the abnormal vibration disappeared after the bolt was fastened. The results of ultrasonic, ultra high frequency PD and SF6 decomposition products were all within the normal range.
