华东电网500 kV任上5237线飑线风致倒塔事故调查分析

Investigation on Tower Collapses of 500 kV Renshang 5237 Transmission Line Caused by Downburst

强风暴是对输电线路威胁最大的一种自然灾害,强风暴导致的高压输电线路和输电塔破坏的事故时有发生。作者首先介绍了华东电网500 kV任上5237线飑线风致10基输电塔连续倒塔事故的现场调查结果,按照输电塔倒塔的严重程度对杆塔进行了分类;分析了飑线风的破坏特性及其对输电线路的危害。对输电塔倒塔的原因进行初步分析后认为: 特大飑线风是造成这次输电塔倒塔的主要原因;输电塔抗风设计规程中横隔面的布置数量不足,导线与输电塔之间的风动力耦联作用也不容忽略。

In all kinds of natural disasters jeopardizing transmission lines, intense storm is the most minatory one, the accidents and failures in high voltage transmission lines and the damage to transmission towers caused by intense storm occur now and then. The authors firstly present the result of field investigation on the failures that ten towers of 500kV Renshang transmission line 5237 collapsed and the flashover of 500kV Renshang lines 5237 and 5238 of East China power grid occurred, those failures were caused by the downburst which hit Siyang County, Jiangsu province on June 14th, 2005. According to the order of severity of transmission tower collapse, the collapsed towers are classified; the destruction characteristic of downburst and its damage to transmission lines are analyzed. The results of preliminary analysis on the reasons of tower collapses show that the extraordinarily intensive downburst is the principal cause of these failures; the quantity of diaphragms designed according to the current design specification for transmission towers to resist wind is insufficient and the dynamic coupling effects between transmission towers and conductors cannot be neglected.