超(特)高压变电站高耸结构避雷针脉动风荷载模拟

Simulation of Fluctuating Wind on EHVAC or UHVDC Transformer Substation's Lightning Rod

近年来发生了若干起高压变电站高耸结构避雷针在风力作用下倒塌的事故,本文通过在事故变电站对季节性风进行实测,对随机脉动风速数值进行模拟分析,分别获得避雷针10、13、24、33、42、52m高度处脉动风速时程曲线及模拟谱、目标谱的对比。在得到风速时程曲线的基础上,对避雷针不同高度处的随机脉动风荷载进行了模拟。应用有限元分析软件对避雷针动力特性进行了仿真,表明避雷针在构架平面外的刚度要小于构架平面内的刚度,说明在风荷载作用下该类型避雷针更易于发生风来流方向的横向(构架平面外)振动。

A number of lightning conductors mounted on tall structures collapsed in high voltage substations due to wind force in recent years. In this paper, the seasonal wind is measured in the incident substations, and by numerical simulation of random fluctuating wind, the time-distance curve of wind speed at heights of 10m, 13m, 24m, 33m, 42m and 52m of the lighting conductors are given, the simulation spectrum and target spectrum are compared as well. Based on the acquisition of time-distance curve of the wind speed, random fluctuating wind load at various heights of lightning conductors is simulated. By using finite element analysis software targeting the dynamic characteristics of the lightning conductors, it is shown that the lightning conductors＇ out-of-plane stiffness is less than that of in-plane, and under the wind load, this type of lightning conductors are more prone to lateral （out-of-plane） vibration following the wind flow direction.