| SF6 gas insulated fully enclosed combination of electrical appliances(hereinafter referred to as GIS),a variety of electrical equipment combined together,greatly reducing the land occupied area,less affected by the external environment,with higher operational reliability,routine maintenance,maintenance cycle Called the traditional power equipment longer advantages,as the power system of high voltage electrical equipment,the most commonly used way.Since the 1980s,GIS equipment in China into the rapid development period.However,when GIS runs for a certain number of years,its problems are gradually exposed:GIS hidden inside the device is not easy to be found,to be hidden after the failure,the fault location and cause of the judge and equipment maintenance is very difficult,the need to deal with failure Power outage range than the conventional open electrical equipment to be large,the need for equipment disintegration inspection,maintenance time span.Therefore,it is urgent to study the common faults in GIS equipment,analyze the fault principle and characteristics,and improve the prevention methods and processing flow.In this paper,the insulation properties of SF6 gas are studied,and the main factors affecting the insulation properties are clarified.SF6 gas has excellent insulation properties,but its insulation strength is affected by many factors.For example,electrode surface state,conductive impurities in the gas,and the like.Therefore,when the applied electric field strength is as high as 10-20 kV/mm,the breakdown voltage of SF6 gas in uniform electric field starts to deviate from Baxing's law.In order to eliminate the micro-burrs on the electrode surface and the effect of the conductive particles in the gas on the strength of the SF6 gas breakdown,the SF6 gas insulation system was subjected to "purification" treatment.Then,the mechanism of partial discharge and the commonly used live detection technology are studied and analyzed,and the common types of GIS faults are introduced.It is pointed out that internal discharge is one of the important factors causing internal faults.Analysis of GIS in the manufacture,transportation and installation process,due to manufacturing processes,collision damage and personnel installation,inspection is not in place and other factors,resulting in damage to components or internal impurities,easy to cause the equipment in the operation of partial discharge,and even cause equipment hit wear.And the discharge process and hazards of the internal discharge types such as free particles,corona discharge,suspension discharge and insulator gap and dendritic discharge are analyzed.The internal discharge faults of the combined electrical appliances are common to the problems of temperature rise,insulation damage and damage of metal parts.Based on the above principle,many kinds of solutions have been put forward by domestic and foreign scholars in the field of combined electrical appliance fault handling,but still exist Therefore,on the basis of the method of live detection,this paper puts forward the idea of using the combination of various means and quality control,and realizes the real-time monitoring and accident warning of the combined electrical fault,and finds out the fault and avoids the further expansion of the fault.In this paper,through the analysis of the causes of internal discharge failure,from the equipment operation and maintenance of preventive measures for the GIS internal fault handling and risk control put forward a new idea,with a wide range of applicability. |
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