The Applied Research Of Shell Vibration Signal In GIS Fault Diagnosis

The Gas Insulated Switchgear (GIS) is used more and more widely in the State Grid. In order to ensure the safe operation of the Gas Insulated Switchgear, prolong the maintenance cycle as much as possible. The research and prediction of detction method in internal latent failure has a sigbificant meaning to the GIS safe operation. The GIS will cause the defects such as metal spikes and particulate because of the problems of manufacture and installation during the operation of GIS, which will cause the discharging fault. Besides, it will produce the abnormal mechanical vibration because of the abnormal condition such as poor contect of the contect terminal, which will lead the mechanical stoppage. This paper investigates the application of the shell vibration signal in GIS fault diagnosis. Through analyzing the characteristics of the discharge and mechanical failure, in view of the discharge disfigurement, using ultrasonic testing, the metal tip, floating potential, insulating pieces inside the air gap, creeping discharge and the characteristics of the metal particle defects. Against mechanical failure, this paper analysis the force situation of GIS equipment, and calculates the GIS of the resonance frequency, investigating the method of vibrating signal inspection by using acceleration sensor, and do a large amount of tests in laboratory. The results indicate that when the contection is good, there is no vibration signal for uniphase GIS. But once there’s contect fault, it will produce electrodynamic force and then the vibration signal comes into being. Especially when the current through the contact is large, it will lead to vibration signal increase rapidly. When the contect is poor, the vibration signals will exist with the fundamental frequency of 100 Hz. When the contect faule is more serious, it will produce frequency component for three times, which are 300Hz and 600Hz. Through the measurement and analysis of GIS enclosure vibration signal, it will detect the vibration condition sensitively and analysis the spectral distribution of signal in time, as well as judge the mechanical failure of GIS and be able to apply to GIS fault dianosis, so that the safe operation of equipment can be ensured.