Study of SF6 gas decomposition products based on spectroscopy technology

Abstract

With the rapid development of power industry, the number of SF₆ electrical equipment are increasing, it has gradually replaced the traditional insulating oil material as insulation and arc media in the high-voltage electrical equipment. Pure SF₆ gas has excellent insulating properties and arc characteristics; however, under the effect of the strong arc, SF₆ gas will decompose and generate toxic substances, then corroding electrical equipment, thereby affecting the insulation and arc ability of electrical equipment. If excessive levels of impurities in the gas that will seriously affect the mechanical properties, breaking performance and electrical performance of electrical equipment, it will cause many serious consequences, even threaten the safe operation of the grid. This paper main analyzes the basic properties of SF₆ gas and the basic situation of decomposition in the discharge conditions, in order to simulate the actual high-voltage electrical equipment, designed and produced a simulation device that can simulate the decomposition of SF₆ gas under a high voltage discharge, and using fourier transform infrared spectroscopy to analyze the sample that produced by the simulation device. The result show that the main discharge decomposition product is SO₂F₂ (sulfuryl fluoride), the substance can react with water and generate corrosive H₂SO₄(sulfuric acid) and HF (hydrogen fluoride), also found that the increase in the number with the discharge, SO₂F₂concentration levels are on the rise. Therefore, the material can be used as one of the main characteristic gases to determine the SF₆ electrical equipment failure, and to monitor their concentration levels.