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

Abstract

To explore the compatibility of C4F7N/CO2 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 C4F7N/CO2 gas mixture except for polyester cushion block and bakelite nut which caused C4F7N decomposed into C3F6 and C3F8, indicating poor compatibility between the gas mixture and polyester cushion block and bakelite nut.