输电线路等效静力风荷载与调整系数计算方法

Calculation method for equivalent static wind loads and wind load adjustment coefficients for transmission lines

为了获得更合理的输电线路设计风荷载,以导线在自重和平均风荷载作用下的静力平衡构型和几何刚度作为计算的初始条件,将导线在脉动风荷载作用下的响应近似视为线性,考虑平均响应和背景响应分量的组合,提出多跨输电导线单目标和多目标等效静力风荷载的计算方法.以某500kV三跨耐张段为研究对象,分别以导线关键位置的顺风向位移和悬垂绝缘子串挂点顺风向反力为等效目标,讨论荷载-响应相关法(LRC)、阵风荷载包络线法(GLE)、多目标等效方法在导线等效静力风荷载计算中的适用性.计算导线的风荷载调整系数,并与我国规范取值进行对比.结果表明,GLE法可用于多跨输电线路的等效静力风荷载计算;规范对风荷载调整系数的取值不尽合理.

The equilibrium configuration and stiffness of conductors under gravity and mean wind loads were taken as the initial conditions for calculation in order to obtain more reasonable design wind loads for transmission lines. Responses of the conductors under fluctuating wind loads were considered approximately linear. Calculation method for equivalent static wind loads on multi-span transmission lines was proposed with consideration of mean response and background response components. Taking a 500 kV strain section for example, the applicability of load-response correlation method, gust loading envelope method and multi-objective method to calculation of equivalent static wind loads on conductors was studied, with equivalent objectives being both along-wind displacements of key points on the conductor and reaction forces of suspension insulator strings as well. Wind load adjustment coefficients of the conductor were calculated and compared with values provided by Chinese codes. Results show that the gust loading envelope method is applicable to calculation of equivalent static wind loads on multi-span transmission lines, and the values of wind load adjustment coefficients provided by the codes are not completely reasonable.