铁路贯通地线雷击瞬态土壤散流及电位分布的计算  

Calculation of Transient Leakage Current and Potential Distribution in Soil Around Railway Connecting Ground Wire Under Lightning

作　　者：吴广宁[1] 李天鸷[1] 曹晓斌[1] 周利军[1] 魏敏敏[1] 段旭东[1] 

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《高电压技术》2013年第4期951-956,共6页High Voltage Engineering

基　　金：铁道部重大专项课题(2011T008);教育部中央高校基本科研业务费专项资金(SWJTU11CX035)~~

摘　　要：为研究贯通地线的瞬态电位分布和土壤散流规律,用无限水平延长接地模型代替贯通地线,在冲击电流下求取其有效散流长度。通过改进电路模型求得了贯通地线的分段电流和土壤散流值,并提出了利用电轴法结合火花放电效应求解指定点电位的方法。实例结果表明,在给定的参数条件下,在接地体中传播约60m泄漏了注入电流总值的99%;贯通地线电流注入点电位达到58.68kV;火花最大放电半径约为14cm。和传统计算方法相比,该计算方法考虑了雷电流在贯通地线中的衰减,以及土壤中火花放电造成的导体等效半径的增大,使得计算结果更趋近实际值。考虑火花放电的影响后,分段电轴法计算得到的贯通地线周围土壤的横纵电位分布规律不变,幅值减小约10%。In order to research the transient potential distribution and leakage current flow regularity in soil of connecting ground wire, we used an infinite horizontal grounding body model instead of connecting ground wire to calculate the effective length under impulse current. Then, we obtained the segment current and leakage current by an improved circuit model, and proposed a solution of speci（ied potential by the electric axis method combined with the spark discharge effect. The results show that, about 99% of the injected current leaks while the current spreads 60 m along earth electrodes under given conditions; the highest potential on the connecting ground wire at the current injection point is 58.68 kV and the largest radius of spark discharge is 14 cm. Compared with traditional methods, the proposed method takes the attenuation of current and the increase of equivalent conductor radius caused by spark discharge into consideration in earth calculation, so the results are closer to actual values. By taking the spark discharge＇s effect into consideration, the potential distribution obtained from electric axis method has no change in pattern, but its amplitude decreases by about 10%.

关 键 词：贯通地线瞬态响应 电轴法 电位分布 土壤散流 火花放电 高铁防雷 

分 类 号：TM862[电气工程—高电压与绝缘技术]