基于塔线体系的中冰区分裂导线不均匀脱冰跳跃研究

Research on Uneven Ice-shedding Jump of Bundled Conductors in Middle Ice Area Based on Tower-Line System

为了掌握中冰区分裂导线不均匀脱冰跳跃特性,考虑输电塔、导线、绝缘子串和间隔棒等构件的力学特点、设置导线阻尼和边界条件,建立了中冰区五档四分裂塔线体系覆冰有限元模型,分析了导线脱冰时张力和脱冰跳跃高度的变化,研究了脱冰位置、脱冰率、脱冰方式、覆冰厚度、线路档距等因素对导线冰跳高度的影响规律,给出了导线冰跳高度工程实用计算公式,并与现行规范值进行比较。结果表明,导线脱冰跳跃呈现先急剧增大后振荡衰减的趋势,覆冰厚度增大,导线运行张力增加;五档四分裂塔线体系中档脱冰时导线跳跃高度大于边档脱冰,档中向档端的非均匀脱冰方式对导线的冰跳高度影响最大,从左往右的脱冰方式其次,均匀脱冰和两边往中间的脱冰方式影响较小。覆冰厚度、脱冰率及线路档距对导线的跳跃高度影响较大;中冰区塔线体系有限元建模方法适用于分裂导线脱冰跳跃计算,利用导线冰跳简化公式可快速计算中冰区高压输电线导线之间的安全间隙。

In order to master the non-uniform ice-shedding jumping characteristics of bundled conductors in middle ice area,considering the mechanical characteristics of transmission tower,conductor,insulator string and spacer,setting conductor damping and boundary conditions,the finite element model of five span tower-line system with four bundle conductor was established.The changes of tension and jumping height of conductor during ice-shedding were analyzed.The influence law of ice-shedding mode,icing thickness,line span and other factors on conductor ice jump height was researched.The practical calculation formula of conductor ice jump height was proposed,and compared with the norm value.The results show that the ice-shedding jumping height increases sharply at first and then decreases,the running tension of conductor increases with the increase of icing thickness.The jumping height of conductor in mid-span ice-shedding is higher than that in side span ice shedding for five span tower-line systems.The non-uniform ice-shedding mode from the middle to the end has the greatest impact on the ice jump height of the conductor,followed by the ice-shedding mode from left to right,the uniform ice-shedding mode and the ice-shedding mode from both sides to the middle have less impact.Icing thickness,ice-shedding rate and line span have great impact on the jumping height of conductor.The finite element modeling method of tower line system in middle ice area is suitable for the calculation of ice-shedding jump of bundled conductors.The safety gap between conductors of high voltage transmission lines in middle ice area can be quickly calculated by using thesimplified formula of ice jumping.