Selection and Existing Problems of GIS Sealing Ring Materials in Alpine Environment

In order to meet the application requirements, the key factors affecting the cold resistance of gas insulated switch (GIS) equipment sealing ring were analyzed, and the sealing ring material suitable for use in alpine environment was selected. The causes of blooming and blowing of GIS equipment sealing ring in alpine environment were analyzed. The results show that the modified ethylene-propylene terpolymer could be used as sealing ring material of GIS equipment in alpine environment. The solubility of active agent and filler in the sealing ring decreases with the decrease of temperature. When it was lower than the critical value, blooming appeared on the rubber surface. When the sealing ring was assembled, the wire diameter decreased due to the stretching of the sealing ring, and the compression ratio of the sealing ring decreased at low temperature, which led to the GIS equipment blowing. The blowing problem could be solved by changing the sealing structure design.