非均匀覆冰下输电导线的脱冰跳跃动力特性

Dynamic Characteristics of Transmission Line Conductors With Non-uniform Accreted Ice After Ice-shedding

冰区架空输电导线上的覆冰脱落会减小导线−地线的绝缘间隙,可能引发闪络跳闸、杆塔倒塌等事故,威胁线路的安全运行。为此采用有限元方法建立输电线路分裂导线模型,研究非均匀覆冰和均匀覆冰对导线动力特性的影响,分析非均匀覆冰导线在不同线路参数和覆冰参数下的脱冰跳跃动力特性,探究各参数对最大冰跳高度、导线最大动张力和最大不平衡张力的影响规律。结果表明:非均匀覆冰形式对脱冰动力特性影响显著,非均匀覆冰下导线的冰跳高度可能大于均匀覆冰下的冰跳高度,且最大冰跳高度所在位置可能不在档距中点,更容易引发闪络事故。因此,研究非均匀覆冰下导线的脱冰跳跃动力特性对重冰区输电线路的绝缘间隙设计具有重要的理论和工程价值。

Ice shedding from overhead transmission lines can reduce the insulation clearance between phase to phase,phase to ground wire,which may cause accidents such as flashover trips and tower collapses,threatening the safe operation of the lines.We used the finite element method to establish a transmission line bundle conductor model.By means of the model,the effects of non-uniform accreted ice and uniform accreted ice on the dynamic characteristics of the conductor were studied,and the dynamic characteristics of transmission line conductors with non-uniform accreted ice after ice shedding under different line parameters and cases parameters were analyzed so as to explore the effect of each parameter on the maximum jump height after ice shedding,the maximum dynamic tension of conductors and the maximum unbalanced tension.The results show that the form of non-uniform accreted ice has a great effect on the dynamic characteristics of transmission line conductors after ice shedding,the maximum jump height of transmission line conductors with non-uniform accreted ice after ice shedding may be greater than that of the uniform accreted ice,and the position of the maximum jump height of transmission line conductors after ice shedding may not be at the mid-point of the span,more likely to trigger flashover accident.Therefore,the study of the dynamic characteristics of transmission line conductors with non-uniform accreted ice after ice-shedding has important theoretical and engineering values for the insulation clearance design of transmission lines in heavy ice zones.