耐张串对UHV导线弧垂影响的现场实测和理论分析

Full-Scale Testing and Theoretical Analysis of Influence of Tension Insulator Strings on the Sag of UHV Conductors

为了分析耐张串重力对特高压导线弧垂和张力的影响,采用现场实测和理论分析方法进行研究。采用GPS和全站仪对某3档线路弧垂进行了现场测试,获得了耐张串和导线弧垂的分布特征,提出了考虑耐张串重力与导线弧垂关系的理论分析方法,基于实测数据拟合了各档的水平张力。研究结果表明:各档导线和耐张串弧垂均呈现明显的悬链线形状,若不考虑耐张串重力影响,拟合结果与实测结果差异较大,耐张段和直线段拟合张力差异最大可达27%;若考虑耐张串重力影响,拟合结果与实测结果差异较小,耐张段和直线段拟合张力差异最大仅为1.7%。说明对于特高压耐张段的弧垂,必须考虑耐张串重力的影响。

In order to study the influence of tension insulator string’s weight on the sags and tensions of ultra-high voltage(UHV)conductors,full-scale testing and theoretical analysis are carried out.The full-scale testing of sags of a three-span transmission line are conducted using global positioning system(GPS)and total stations,and the sag’s distribution characteristics of tension insulator strings and conductors are obtained.A theoretical analysis method is developed with consideration of the correlation between tension insulator string’s weight and conductor’s sags,and the horizontal tension forces of transmission lines are fitted based on the full-scale testing data.The results show that both the conductors and tension insulator strings have a shape of catenary curve in sag.When the tension insulator string’s weight is not considered,the fitting results differ significantly from the testing results,with the maximum discrepancy of fitting tension between the strain section and the straight section reaching 27%.When the tension insulator string’s weight is considered,the difference between fitting results and testing results is quite small,with the maximum discrepancy of fitting tension between strain section and straight section being only 1.7%.It can be seen that the influence of tension insulator string’s weight must be considered in determining the sag of a strain section of UHV transmission lines.