台风作用下输电线路风振系数及抗风性能研究

为研究良态风与台风作用下的输电线路风振系数，以广东省国古线一铁塔为原型建立了有限元模型，采用谐波叠加法模拟了台风风场，并开展了动力分析.首先，对比了5种国内外设计规范的风振系数计算方法，发现各规范均未单独考虑台风的强脉动特性；然后，基于惯性力法获取了铁塔风振系数并揭示了塔线耦联效应的影响.最后，利用生死单元法定量评估了两种风场下输电线路的抗风性能.结果表明:台风的高湍流特性导致顺风向风振系数大于良态风对应值；导线可增大铁塔横风向基频，并使铁塔振型由单塔的弯曲型变为塔线体系的弯剪型，塔线体系横担处风振系数大于单塔；湍流度从0.14提高至0.20，临界倒塌风荷载降低约11%.因此，台风多发地区的输电塔设计应适当提高湍流度取值，必要时还应考虑塔线耦联效应.

Research on Gust Response Factor and Wind-Resistance Performance of Transmission Lines Under Typhoon

To study the gust response factors(GRF) of transmission lines under normal wind and typhoon， a finite element model is established based on a steel tower of the Guogu line in Guangdong Province. The typhoon wind field is simulated via a harmonic superposition method， and the dynamic analysis is carried out. First， the GRF methods in five design codes at home and abroad are compared. It turns out that none of them considers the strong fluctuating characteristics of typhoon. Then， the GRF is obtained based on the inertia force method， and the tower-line coupling effect on GRF is studied. Finally， the wind-resistance performance of the transmission line under the two wind fields is quantitatively evaluated by the method of birth to death element. The results showed that the high turbulence characteristics of typhoons lead GRF to be greater than that of normal wind and the conductor can increase the natural frequency of the tower in the cross-wind direction， changing the mode from the bending type of a single tower to the bending-shear type of the tower-line system， whose GRF at the cross arm is greater than that of a single tower. The critical collapse wind load will decrease by 11% if the turbulence intensity increases from 0.14 to 0.20. Thus， the design of transmission towers in typhoon-prone areas should properly increase the turbulence intensity and take into account the tower-line coupling effect when necessary.