摘要
为分析动车组避雷器炸裂原因,对炸裂和检测不合格的避雷器进行了解体检查,研究发现在阀片侧面存在电蚀痕迹,阀片上下表面存在白色粉末状物质,绝缘筒内表面存在树枝状放电通道。能谱分析表明,缺陷阀片表面的白色粉末状物质含有明显的氧元素,是内部受潮氧化所致。为分析其电树枝的形成原因以及内部水分对电场分布影响,建立了有限元仿真模型,对弹簧定位块位置偏移、绝缘筒存在电树枝和泄放口附近存在裂纹3种情况下的电场分布情况开展了仿真研究。仿真结果表明,弹簧定位块位置的偏移对绝缘筒内表面电场影响较大,当定位块紧贴绝缘筒时,场强为22.23 kV/cm,可在过电压作用下形成电树枝;电树枝对绝缘筒内表面电场存在畸变作用,电树枝一旦形成可进一步畸变电场,引导电树枝往前发展;在干燥情况下,泄放口附近裂纹对绝缘筒内表面场强影响不大,而当避雷器受潮时,裂纹端部场强可以达到26.1 kV/cm,可能引发局部放电,并引导电树枝往泄放口发展。
In order to analyze the reasons for the explosion of lightning arrester of Electric Multiple Units(EMU),the explosion and unqualified lightning arrester were disassembled and inspected.It was found that there were traces of electric corrosion on the side of the valve plate,white powder on the upper and lower inner surfaces of the valve plate,and dendritic discharge channels on the inner surface of FRP cylinder.Energy spectrum analysis shows that the white powder material on the inner surface of the defective valve plate contains obvious oxygen element,which is caused by internal moisture and oxidation.In order to analyze the cause of the formation of electric branches and the influence of internal moisture on the electric field distribution,a finite element simulation model was established to simulate the electric field distribution in three cases:the displacement of spring positioning block,the existence of electric branches in FRP cylinder and cracks near the discharge port.The simulation results show that the displacement of the spring positioning block has a great influence on the electric field on the surface of the FRP cylinder.When the positioning block is close to the FRP cylinder,the electric field strength is 22.23 kV/cm,which can form electric branches under the action of overvoltage;The electric tree has distortion effect on the surface electric field of FRP cylinder.Once the electric tree is formed,it can further distort the electric field and guide the electric tree to develop forward;Under dry conditions,the crack near the discharge port has little effect on the inner surface field strength of the FRP cylinder.When the arrester is damp,the field strength at the crack end can reach 26.1 kV/cm,which may cause partial discharge and guide the electric branch to the discharge port.
作者
刘健
欧琦
刘正威
左明洁
张妍
王胜辉
毛帅涛
张启哲
LIU Jian;OU Qi;LIU Zhengwei;ZUO Mingjie;ZHANG Yan;WANG Shenghui;MAO Shuaitao;ZHANG Qizhe(CRRC Changchun Railway Vehicles Co.,Ltd.,Changchun 130011,China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China)
出处
《电瓷避雷器》
CAS
北大核心
2023年第5期28-36,共9页
Insulators and Surge Arresters
基金
国家重点研发计划(编号:2018YFF01011903)。
关键词
解体检查
受潮
电树枝
裂纹
局部放电
disassembly and inspection
damp
electrical treeing
cracks
partial discharges
