输电线路多塔耦联体系的风致动力响应分析

输电塔结构的安全直接关系到国家电网的运行可靠性,而风荷载则是威胁其安全的主要外因之一。基于此,首先以华东某500 kV输电线路的典型输电塔结构为背景,在有限元程序AN SY S开发环境下,建立了包含三塔两线的塔线耦联体系精细化有限元分析模型;然后,应用经典的基于功率谱密度函数的谱表现方法,结合D avenport谱生成了目标场地的风场;最后,利用该生成风场,进行了上述输电塔耦联体系模型的抗风动力响应分析,进而对比了输电塔的拟静力计算结果与多塔耦联体系的动力响应计算结果。研究结果表明,中国现行输电塔抗风设计方法是偏于不安全的,有待进一步的改进。

Dynamic Wind-Induced Response Analysis of Multi-Tower-Line Coupled System of Transmission Line

Structural safety of transmission towers is directly related to the reliability of the state grid. In fact, wind loading is taken as one of the main harmful factors. Until now, how to consider the tower-line coupled problem in dynamic response analysis has not been fully resolved, although many researchers have studied this problem. In this paper, based on typical transmission tower design in a 500 kV transmission line, a finite element model of a multi-tower-line coupled system, including three towers and two-span lines, is established using the development environment of international finite element method program ANSYS. Then, the classical spectral representation method based on power spectrum density functions is applied, and Davenport spectrum is used to generate wind speed histories of a given field. Finally, this generated wind field is applied in wind-induced dynamic response analysis of the coupled system, and the dynamic response results of the middle transmission tower in the above coup quasi-static analytical results of the solo tower. It is found that the horizonta ed system are compared with displacement response of the tower top increases 9% and the increment of axial compressive stress of some elements can reach 84.6%. It can be concluded that the results by the current wind resistant design method for the transmission towers are unreliable and the design method needs to be modified.