直供方式下接触网避雷线防雷效果分析

Analysis of Lightning Protection Performance of OCS for Electrified Railway

电气化铁路接触网绝缘水平较低,接触网一旦遭受雷击将对接触网造成严重危害。接触网架设避雷线是一种有效的直击雷防护措施,对提高接触网雷电防护性能具有重要意义。为研究接触网避雷线的防雷特性,本文利用ATP-EMTP,仿真分析直供方式下回流线升高兼做避雷线和单独架设避雷线两种避雷线架设方案的雷电防护性能,同时基于滚球法分析了避雷线的架设高度。计算结果表明:回流线升高和单独架设避雷线均可以有效提高接触网的反击耐雷水平,单独架设避雷线情况下接触网所对应的耐雷水平具有较好的改善效果。文章利用滚球法推导了避雷线高度的计算公式,可以根据接触网的几何结构迅速确定避雷线的架设高度,且可有效应用到实际工程中。

The insulation level of OCS forelectrified railway is low. Once the OCS has been struck by lightning, it will cause serious harm to the OCS. The lightning conductor is an effect measure to protect the catenary from the direct lightning and it is great significant to improve the lightning performance. To study the characteristics of lightning performance, the lightning performance of two schemes which include elevating return line and erecting the lightning conductor has been analyzed by use of ATP-EMTP software in this paper, while the erection height has been analyzed based on rolling ball method. The results show that both of the two schemes can improve the lightning withstand level of catenary. The lightning withstand level of erecting lightning conductor is higher. The formula of height of lightning conductor is deduced by rolling ball method in this paper. The height of lightning conductor can be quickly determined according to the geometric structure of OCS. The rolling ball method can be effectively applied to practical engineering.