PRINCIPAL DECOMPOSITION BY-PRODUCTS GENERATED AT VARIOUS ABNORMALITIES IN GAS-INSULATED TRANSFORMERS

Gas analysis provides a promising means for a diagnosis of gas-insulat ed equipment. Although many studies have been concentrated on SF6 gas decomposition, they were mostly related to the faults in GIS systems a nd not directly applicable to gas-insulated transformers, who have muc h complicated material structure. An experimental survey over decompos ition by-products at various abnormal conditions was carried out by us e of simulating models to develop a diagnostic method for gas-insulate d transformers based on gas and ion chromatograph analyses. Major comp onents characteristic to each abnormality, such as SO2 on metal overhe at, SO2F2 on partial discharges, etc. were identified by the experimen ts.