摘要
采用有限元软件ANSYS建立铁塔-导线-地线-绝缘子的三维塔线系统有限元模型,考虑塔线耦合效应、脱冰相位置及数量、冰厚、档距和高差等影响因素,完成了不同工况下的塔线系统脱冰跳跃动力分析,确定了导线跳跃高度、挂点荷载及其动力放大系数和铁塔杆件内力的变化规律。对于2008年冰灾500 kV实际线路段的脱冰跳跃动力分析表明,在设计冰厚工况下,脱冰量较大时,导线脱冰跳跃会导致塔头杆件应力超限而发生破坏。对于上相脱冰情况,在脱冰档安装三角形相间间隔棒后,脱冰档跳跃高度和挂点不平衡张力明显降低,设计冰厚下铁塔处于安全状态。为防治塔线系统脱冰跳跃事故,应在事故多发段采用相间间隔棒,并根据脱冰跳跃挂点荷载计算值对铁塔塔头薄弱杆件进行适当加强。
A three dimensional finite element model of tower-conductor-ground wire-insulator system was established in ANSYS, and the dynamic responses of ice shedding under different cases were analyzed for transmission tower-line system. Many factors were considered in the ice shedding simulating analysis, which includes tower-line coupled effect, the quantity and location of conductor phases, thickness of the aeereted ice, length of span as well as elevation difference. Influences of all the factors on the dynamic responses of jumping heights, loads at the end of insulator and the forces of transmission tower were mainly studied, lee shedding simulating analysis of an actual 500 kV transmission line section which happened ice disaster in 2008 was completed, and the results show that stress ratios of the members at tower head under design ice thickness will exceed the limited values when the amount of ice shedding is much larger. For the ice shedding at the top phase conductors, the jumping height and unbalanced tension at the end of insulator can be reduced obviously by applying triangular phase to phase spacers, and the tower is in safe state under design ice thickness. As to prevent ice shedding accidents, phase to phase spacers should be used, and the weak members at tower head should be strengthened according to the calculated load values at the end of insulators.
出处
《振动工程学报》
EI
CSCD
北大核心
2010年第1期86-93,共8页
Journal of Vibration Engineering
基金
国家电网公司科技项目(GCHZ200802)
关键词
塔线系统
脱冰跳跃
耦合效应
不平衡张力
动力放大系数
相间间隔棒
tower-line system
ice shedding
coupled effect
unbalanced tension
dynamic amplifying coefficient~ phase tophase spacer
