无应力原长的覆冰输电线路找形研究

Study on Form-finding Analysis of Transmission Line with Ice-coating Based on Unstressed Initial Length

为改善目前输电线路找形方法中存在的步骤繁琐、计算效率低和收敛性差等问题,提出了基于无应力原长的找形分析法。该方法基于悬链线方程,通过计算输电线无应力时长度和它相对弦线的伸长量来获得找形分析的模型和参数,然后将输电线变形等效为温度变化和比载共同作用的结果,进行有限元找形分析从而获得输电线有无覆冰时的静力学形态。基于实际线路观测的弧垂和张力验证了本方法的准确性,与其他找形方法对比,本方法设置简单且计算效率高。研究结果可为覆冰输电线路的找形提供新思路。

A novel form-finding analysis method based on unstressed initial length was suggested in this paper to improve the disadvantages of traditional approach such as complicated steps,low computational efficiency and poor convergence.Based on the catenary equation,the initial length at no stress condition of transmission line and the change between it and the length of chord were calculated as the initial parameters in form-finding analysis.Then the deformation of transmission line from no stress condition to catenary was equivalent to the effect caused by temperature changes and specific load.Based on finite element method,the form-finding analysis was carried out to obtain the static shape of the transmission line before and after icing.Subsequently,this method was well verified by the measurements of sage and tension of actual transmission line before and after icing.Finally,the comparison of results between this method and other form-finding methods was conducted.The error evaluation suggested that the unstressed initial length method exhibited advantages of high computation efficiency and parameters setting easily.This research could help to provide new approach for the form-finding analysis of icing transmission lines.