Study on the Compatibility of Typical Materials in GIT with C4F7N/CO2 Gas Mixture

To explore the compatibility of C 4 F 7 N/CO 2 gas mixture and typical materials used in gas insulated transformer (GIT), thermal accelerated aging test was carried out and the gas mixture after test was analyzed by gas chromatography-mass spectrometry (GC-MS) to estimate the interaction intensity between the reactants. The results showed that most of selected materials have good compatibility with C 4 F 7 N/CO 2 gas mixture except for polyester cushion block and bakelite nut which caused C 4 F 7 N decomposed into C 3 F 6 and C 3 F 8 , indicating poor compatibility between the gas mixture and polyester cushion block and bakelite nut.