Internal Arcing Fault Analysis And Enclosure Structural Design Of 252kV GIS

Gas Insulated Switchgear(GIS),being an important switchgear in the power system,has been widely used at home and abroad benefiting from its excellent electrical performance,but internal arcing fault(IAF)is considered to be the most serious fault that may occur during the life span of SF6 Gas Insulated Switchgear.Internal arcing fault will not only affect the safety and reliability of the equipment,but also pose a serious threat to the safety of operation and maintenance personnel.Analyzing the internal arcing fault in GIS can save a lot of test cost,and shorten the development cycle of new products.The results can be used as a guidance to improve the existing products and develop new products,which are of great significance for the development of GIS.252 k V GIS was taken as an example to carry out related research in this paper.The main contents include the following parts:Firstly,by studying the characteristics and mechanism of internal arcing fault,the developing process and behavioral characteristics of internal arcing fault in GIS were clarified.According to the research object,the test standards and qualification criteria were determined.The test of internal arcing fault was carried out,and the test results of arc current,arc voltage and gas pressure were recorded.Secondly,arc energy was calculated by using its model;the Enhancement of Improved Standard Calculation Method(EISCM)was proposed based on the Improved Standard Calculation Method(ISCM).The gas pressure in arcing room was numerically simulated,and the effectiveness of two numerical simulation methods mentioned above and the superiority of the latter were verified by comparing the calculating results with the test results.Besides,the numerical simulation calculation of burn-through was carried out by using the model of the probability of enclosure burn-through.Thirdly,the standard and direction of GIS enclosure protection were clarified;the gas pressure rise in arcing room and enclosure burn-through were considered as the characteristic parameters of the external effects of internal arcing fault.Through the numerical simulation,the influence of enclosure parameters on two characteristic parameters was analyzed,including enclosure thickness,inner diameter,length,flange thickness,bursting pressure and the area of bursting disc.Based on the results,an optimization design of enclosure structural was proposed,and its numerical simulation was carried out.Finally,a numerical simulation platform of internal arcing fault in GIS was designed by using VBA and SQL mixed programming,which includes multiple modules such as “login and logout”,“data input”,“data conversion” and “data management”.Moreover,the function of query and traversal of simulation data was realized by using MySQL database.