摘要
研究目的:随着雷击故障日益突出,地铁工程中开始利用架空地线进行雷电防护。但地铁中为车辆供电的架空接触网架设在轨道上方、绝缘水平很低,与电力系统输电线路差别较大,有关设计规范中缺少相应的规定,导致目前国内地铁工程中对架空地线的防护作用缺乏系统研究。工程中已实施的方案存在较大差异,有必要进行系统的研究。本文采用电气几何模型法,研究得出架空地线安装位置与雷击闪络次数、避雷器放电电流的关系,提出了架空地线防雷接地解决措施,最后提出工程应用建议。研究结论:(1)地铁架空地线可降低接触网雷击闪络次数,且导线高度越高时效果越明显,地铁工程中利用架空地线进行雷电防护是有益的;(2)架空地线安装在导线上方和安装在支柱顶部时接触网总闪络次数差别不大,工程中推荐采用安装在支柱顶部方案;(3)架空地线对保护绝缘子用带串联间隙金属氧化物避雷器的动作冲击电流具有分流作用,架空地线安装在支柱顶部高度以绕击的次数低于0.1次/100 km·a(以40个雷暴日计)为指标进行校验取值,推荐安装位置为高出导线1 m;(4)当架空地线兼具防雷使用时,应做好架空地线的接地,并阻止正常运行时杂散电流就地泄放,建议接地引下线串接由气体放电管和金属氧化物电阻片构成的雷电冲击接地器;(5)本研究成果可应用在城市轨道交通领域。
Research purposes： With the lightning faults increasing, overhead ground wire has been used for lightning protection in metro projects. The overhead contact system （OCS） for the vehicle power supplying in metro is different with the power system transmission line, because it was installed above the track and its insulation level is very low. The relevant provisions are lacking in the design codes. The protective effect of overhead ground wire has not been systematically studied in the current domestic metro. There are great differences in the projects that have been implemented. Therefore, it is necessary to study the lightning protection effect of metro overhead ground wire. Using electrical geometric model （EGM）, the relationship of the overhead ground wire installation position with lightning flashover times and the lightning flashover arrester discharge current has been studied in this paper. The proposed solution is given for lighting protection earthing of overhead ground wire. Finally, the application suggestions in metro are put forward in this paper.Research conclusions： （ 1 ） The overhead ground wire can reduce the number of lightning flashover of the OCS. TheOCS is higher, the effect is more effective. The overhead ground wire is beneficial to lightning protection in metro. （2） The total lightning flashover times are almost the same whether the overhead ground wire is installed above the OCS or at the top of the pillars. So the overhead ground wire installed at the top of the pillars is suggested to be used. （3） The overhead ground wire can reduce the impact current of metal oxide surge arrester with series gap. The height of the overhead ground wire should be checked to reduce the flashover times of shielding failure to 0.1 times / 100 km· a （40 thunderstorm days）. It is suggested that the overhead ground wire is 1 meter higher than the OCS. （4） It is suggested that the earthing device for lighting which is composed of a gas discharge tube and a metal oxide resistor sh
出处
《铁道工程学报》
EI
北大核心
2015年第1期122-128,共7页
Journal of Railway Engineering Society
关键词
地铁
架空地线
雷电防护
作用
雷电冲击接地器
metro
overhead grounding wire
lighting protection
effect
earthing device for lighting
