How to produce SF6 decomposition products in high voltage electrical equipment, and what are the detection methods?- SF6在线监测系统_SF6检漏仪_SF6传感器_SF6密度继电器

韦弗斯新闻动态

最新动态

SF6安全保障专家

专注于SF6气体检测的专业化

135 85763546

How to produce SF6 decomposition products in high voltage electrical equipment, and what are the detection methods?

发布时间：2016-09-30 来源：ydlcb 浏览次数：43次

SF6 electrical equipment internal insulation materials, including SF6 gas and solid insulation materials two categories.

SF6 gas is common to all SF6 electrical equipment, while solid insulation materials vary from equipment to equipment, mainly thermosetting epoxy resin, polyester nylon, polyester vinyl, polytetrafluoroethylene, insulating paper and insulating paint. The decomposition temperature and decomposition products of different insulating materials are different. Among them, at 130℃, polyvinyl, paper and paint began to decompose, mainly producing CO, CO2 and low molecular hydrocarbons; Above 400℃, polytetrafluoroethylene begins to decompose and mainly produces CF4. Above 500℃, SF6 gas and thermosetting epoxy resin begin to decompose, mainly producing SO2, SOF2, H2S, CO and HF.

SF6 gas and thermosetting epoxy resin have good thermal stability, for normal operation of SF6 electrical equipment, its internal temperature is only 5℃-10℃ higher than the ambient temperature, therefore, there will be no decomposition of insulating materials, SF6 gas without the above decomposition products. However, if there is partial discharge, reignition and severe overheating fault in the equipment, the solid insulation material and SF6 gas in the fault area will decompose, resulting in decomposition products such as SO2, H2S, CO and HF.

In the process of technical supervision and fault diagnosis of SF6 electrical equipment for a long time, I have a deep understanding of the principle, structure and internal insulation materials of SF6 electrical equipment. After studying the cracking mechanism of various insulation materials and the characteristics of decomposition products in the case of equipment failure, and conducting statistical analysis of a large number of fault cases, I have obtained a deep understanding of SF6 electrical equipment. The characteristic components of SF6 gas (SO2, SOF2 and HF are the characteristic components of SF6 decomposition; H2S is the characteristic component of decomposition of thermosetting epoxy resin. CO is the characteristic component of decomposition of polyester ethylene, insulating paper and insulating paint. CF4 is the characteristic component of polytetrafluoroethylene decomposition) content to judge the failure of SF6 electrical equipment.

When there is a fault inside the SF6 electrical equipment, SF6 gas and solid insulation materials in the fault area will be cracked under the action of heat and electricity to produce SO2, SOF2, H2S, CO, HF and CF4 and other characteristic components, so the detection of the content of these characteristic components can diagnose the internal fault of the equipment. However, due to the small content of latent fault characteristic gas and poor fluidity of SF6 gas, decomposition products are slowly dissolved into SF6 gas mainly by means of weak convection caused by dissolution, diffusion and changes in ambient temperature. Therefore, it is necessary to select detection methods and instruments with high sensitivity, good stability and fast reaction speed.

At present, the detection methods of SF6 electrical equipment decomposition products include electrochemical method, chemical colorimetry, chromatography, ionization method, dynamic ion method and infrared method.