摘要
兰新线风沙环境中沙粒同环氧树脂绝缘子伞裙边缘碰撞后可造成伞裙边缘蚀损,蚀损后的绝缘子爬电距离减小,爬距减小会增加绝缘子闪络故障概率。为获取沙粒粒径对动车组车顶环氧树脂绝缘子伞裙边缘蚀损情况,将与来流方向平行的伞裙直径所通过的伞裙边缘定义为0°和180°,与来流方向垂直的伞裙直径在伞裙边缘的2个点定义为90°和270°,在闭式风洞内将风速设定为57 m/s,试验时长设定为160 h,单次沙粒质量为20 kg,试验获取0.5 mm及以下、0.25 mm及以下和0.1 mm及以下等3种沙粒粒径对伞裙不同位置处的半径减小值。试验结果表明:逆时针方向旋转,90°~270°之间的伞裙边缘无蚀损,蚀损部位均位于0°~90°、270°~360°之间;沙粒粒径<0.25 mm或<0.1 mm时,伞裙半径减小值均<0.5 mm;沙粒粒径为0.25~0.50 mm时,伞裙40°~60°之间蚀损最严重,且7号伞裙蚀损量最大。粒径影响伞裙边缘蚀损程度的原因是碰撞前动能不同,小粒子跟随性好,大粒径粒子跟随性差所致;40°~60°之间蚀损最严重,该结果同基于Finnie微切削理论和计算流体力学理论获得的仿真计算分析结果相符。该研究结果可为不具备试验条件工况下采用仿真手段评估风沙环境中绝缘子伞裙蚀损程度及其结构优化设计提供参考依据。
In the sandstorm environment of Lanzhou-Xinjiang railway line,the collision between sand particles and the sheath edge of epoxy insulator can cause the edge erosion of the sheath,and the creepage distance of the insulator decreases,which will increase the probability of insulator flashover.In closed wind tunnel tests,the wind speed was set for 57 m/s,the test time was set for 160 h,and the sand quality was 20 kg each time.The sheath edge which is parallel to the direction of incoming flow and passes by sheath diameter,is defined as 0°and 180°.The two points of intersection of sheath diameter perpendicular to the direction of incoming flow and sheath edge are defined as 90°and 270°.In the experiments,the radius reduction value of the sand particle sizes of 0.5 mm and below,0.25 mm and below,and 0.1 mm and below can be obtained in different positions of the sheath to get the sand grain size of the EMU roof edge erosion situation of epoxy resin insulators sheath.The test results show that the edge of the sheath between 90°and 270°is not corroded by counterclockwise rotation,and the wear parts are all between 0°and 90°,between 270°and 360°;When the sand particle size is less than 0.25 mm or less than 0.1 mm,the reduction value of sheath radius is less than 0.5 mm.When the sand particle size is 0.25~0.50 mm,the most severe wear occurs between 40°and 60°,and the No.7 sheath has the greatest wear.The reasons that particle size affects the degree of sheath edge erosion are that the kinetic energy before collision is different,small particles have good follow ability and large particles have poor follow ability.The most severe corrosion occurs between 40°and 60°,which is consistent with the simulation analysis results based on Finnie micro-cutting theory and computational fluid dynamics theory.The results of this paper can provide a reference for the simulation method to evaluate the corrosion degree of insulator umbrella skirt and its structural optimization design in sandstorm environment without the conditions to do the experiment.
作者
马建桥
王稳稳
王向飞
耿江海
陈坤
包艳艳
MA Jianqiao;WANG Wenwen;WANG Xiangfei;GENG Jianghai;CHEN Kun;BAO Yanyan(College of Automation&Electrical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense,North China Electric Power University,Baoding 071003,China;Wuhan NARI Limited Liability Company,State Grid Electric Power Research Institute,Wuhan 430074,China;State Grid Gansu Electric Power Research Institute,Lanzhou 730070,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2020年第7期2496-2503,共8页
High Voltage Engineering
基金
国家重点研发计划(2016YFB1200403)
甘肃省教育厅项目资助计划(2018A-025)
甘肃省科技计划(17JR5RA083)。
关键词
动车组
环氧树脂绝缘子
高速气流
风沙蚀损
风洞试验
electric multiple units(EMU)
epoxy insulator
high speed airflow
wind-sand abrasion
wind tunnel experiment
