基于先导发展法的特高压直流输电线路绕击特性分析  

Lightning Shielding Failure Characteristics of UHVDC Transmission Line Using Leader Progress Method

作　　者：王志勇[1,2] 余占清[1] 李雨[1] 何金良[1] 耿屹楠[1] 梁曦东[1] 

机构地区：[1]清华大学电机工程与应用电子技术系电力系统及发电设备控制与仿真国家重点实验室,北京100084 [2]南方电网公司广州供电局,广州510620

出　　处：《高电压技术》2011年第9期2178-2184,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724504)~~

摘　　要：雷电绕击是影响高压输电线路安全稳定运行的关键因素之一,特高压直流线路对雷电防护的需求与常规线路相比更加迫切。为此介绍了基于先导发展法的特高压直流线路雷电绕击跳闸率分析方法;利用该方法针对±800 kV特高压直流线路绕击特性开展仿真研究,分析了绕击跳闸率随绝缘水平、保护角的变化规律,研究了典型地形条件下雷电绕击路径和绕击电流的分布特性,分析了山坡、山脊和跨谷地形条件下线路的绕击跳闸率,研究了线路极性对跳闸率的影响。研究表明,减小保护角可明显降低绕击跳闸率,在山坡地形条件下,外侧导线由于受屏蔽减弱更易受到雷击,雷电先导可从近似水平的方向击中导线;跨谷深度增加时,由于地面屏蔽作用减小,雷击跳闸率明显提高;理论分析和运行经验都表明,直流线路正极导线遭受雷击的概率远高于负极,线路位于山脊时雷电绕击基本发生在正极导线侧。Shielding failure of lightning is the key problem for safe operation of high voltage transmission lines,and lightning protection for ultra high voltage DC transmission lines are more significant.The method for analyzing the shielding failure rate of ultra high voltage transmission lines based on the leader progress method was introduced,by which the shielding failure characteristics were calculated.Effects of insulating levels,shielding angles and terrains on shielding failure rate were analyzed.Moreover,lightning path and current distribution of shielding failure under typical terrains were studied,and influence of polarity on shielding failure rate was analyzed.Results show that the shielding failure rate decreases with the decreasing of shielding angle.The conductor at outside of mountain slope is easier to be stricken because the shielding effect of ground lines is worse,and the lightning may strike the conductors horizontally.The shielding failure rate rises with increasing of valley depth.It is shown by both calculation and operation experiences that the shielding failure rate of the positive pole is much higher than the negative pole,and shielding failure trips almost happen on the positive pole on top of mountain ridges.

关 键 词：特高压(UHV) 直流(DC) 输电线路 雷电防护 绕击 先导发展 

分 类 号：TM863[电气工程—高电压与绝缘技术]