Research on the Characteristics of SF6 Decomposition Products in Discharge Conditions

• Main Authors: Yu-long, Miao, Congdong, She, Qiang, Yao, Ni, Qiu, Yu-shan, Hou, Fu-ping, Zeng
• Format: Conference Proceeding
• Language: English
• Subjects: characteristic gas; Discharges (electric); Electrodes; fault diagnosis; High-voltage techniques; Monitoring; Power systems; simulated discharge experiment; Solids; Sulfur hexafluoride
• ISSN: 2474-3852
• DOI: 10.1109/ICHVE49031.2020.9279554

Research on the determination of the product gas decomposed by sulfur hexafluoride (SF 6 ) in diverse discharge conditions is of considerable significance for the status evaluation of related electrical equipment. In this paper, the discharge experiment of SF 6 medium was conducted with a needle-plate electrode simulating the operating environment of gas insulated substation (GIS). The products were measured by gas chromatography, ion chromatography and other instruments, by which the appearance moment and content variation of HF, SO 2 F 2 , CF 4 , hydrolysable fluoride and other decompositions generated at 50 kV power frequency are illustrated. The formation of the product at lower energy conditions was investigated as a comparison by the discharge test at 14kV, and further experimental investigation was carried out with the electrode spacing of 0.2cm. This article also analyzed the impact of solid insulating medium (such as polyester film) on characteristic breakdown products by the discharge experiment involving solid insulating medium. The results indicated that HF was the first to be generated despite of the discharge energy, and the detected moment of SO 2 F 2 will be delayed with the decrease of discharge energy, as its concentration promoted when the discharge energy augmented. CF 4 was found in different discharge experiment, and a higher concentration of CF 4 was supposed to be related with the participating of solid insulating media. The experiment launched in this paper considered all forms of discharge fault in SF 6 electrical equipment in general and measured the consistence of breakdown gas of SF 6 correspondingly. The conclusion in this paper could contribute to the beforehand diagnosis and monitoring of sudden failures caused by discharges in SF 6 electrical equipment.