输电线路绕击特性的三维分析方法  

Three-dimensional Analysis Method of Shielding Failure Characteristics of Transmission Lines

作　　者：吴广宁[1] 熊万亮[1] 曹晓斌[1] 李瑞芳[1] 朱军[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2期374-382,共9页High Voltage Engineering

基　　金：国家电网公司科技项目(2011-WG-4);教育部中央高校基本科研业务费专项资金(SWJTU11CX035)~~

摘　　要：为了定量分析输电线路不同位置的雷击概率、绕击跳闸率数值分布特性,避免电气几何模型法中由各个截面雷击概率的不等效替换产生的不可控误差,利用输电线路悬链线方程,将传统计算方法中的雷击暴露宽度沿着输电线路每个档距拓展为三维暴露空间,提出了输电线路绕击特性和暴露空间内任意截面暴露宽度的三维分析计算方法,推导了任意截面雷击概率及绕击跳闸率的三维计算公式,并修正了总跳闸率计算公式。以500kV双避雷线输电线路为例,计算得到了输电线路档距内雷击暴露宽度的三维分布,以及雷击概率、绕击跳闸率的二维分布,结果显示同一档距内绕击跳闸率最大值是最小值的9.02倍,最大值是按原绕击跳闸率公式计算总跳闸率的2.54倍。该方法表明输电线路不同截面雷击概率差别很大,线路总绕击跳闸率并不能完全真实地反映输电线路任意截面的实际雷击情况。In order to quantitatively analyze the numerical distribution characteristic of lightning probability and shielding failure trip-out rate in different position of transmission lines,and to avoid the uncontrollable error resulting from inequivalent replacement of lightning probability of each section,using the catenary equation,we expanded the lightning exposed width of traditional calculation method to three-dimensional exposed space alone every span of transmission lines,and proposed a three-dimensional analysis method of shielding failure characteristics of transmission lines and a three-dimensional calculation method of exposed width of arbitrary section in exposed space.Then,we derived the three-dimensional equations of lightning probability and shielding failure trip-out rate of arbitrary section,and revised the equations of total shielding failure trip-out rate.Moreover,taking 500 kV transmission lines with two overhead ground wires as an example,we calculated the three-dimensional distribution of lightning exposed width as well as the two-dimensional distribution of lightning probability and shielding failure trip-out rate.The results show that the maximum of shielding failure trip-out rate in a span is 9.02 times more than the minimum,and 2.54 times more than the total shielding failure trip-out rate calculated by original formulas.This method indicates that the lightning probability in diverse section is very different and that the total shielding failure trip-out rate can not really reflect the actual lightning stroke in arbitrary section of transmission lines.

关 键 词：电气几何模型法 平均高度 暴露宽度 暴露空间 雷击概率 绕击跳闸率 

分 类 号：TM751[电气工程—电力系统及自动化]