强扭转激励下特高压单柱拉线塔动态响应研究

发布时间：2018-03-31 16:44

本文选题：单柱拉线塔　切入点：强扭转激励　出处：《华北电力大学》2017年硕士论文

【摘要】：不同于自立式输电塔,特高压单柱拉线塔的第一阶振型为扭转振动。在脱冰或断线致强扭转激励作用下,可能使单柱拉线塔产生大幅的扭转振动。因此,脱冰或断线致强扭转激励下特高压单柱拉线塔的动态响应值得研究。本文主要研究内容如下:首先,建立了特高压单柱拉线塔塔线体系简化有限元模型,通过与全精确有限元模型进行模态分析的对比,证明了所建塔线体系简化模型的正确性;在塔线体系简化模型的基础上建立了塔线体系覆冰有限元模型,通过理论计算验证了塔线体系覆冰有限元模型的准确性。其次,通过和文献中的导线脱冰试验进行对比,验证了输电线脱冰数值模拟方法的正确性;分析了脱冰致强扭转激励下特高压单柱拉线塔动态响应特点;研究了改变拉线初应力对脱冰致强扭转激励下单柱拉线塔动态响应的影响。最后,通过和文献中的导线断线试验进行对比,验证了输电线断线数值模拟方法的正确性;对未覆冰断导线、覆冰断导线、覆冰断地线三种工况下单柱拉线塔的动态响应进行了分析。研究结果表明:在脱冰和断线致强扭转激励作用下,单柱拉线塔拉线挂点以上主柱产生了扭转变形,拉线挂点以下主柱产生了随拉线挂点截面的刚体转动;主柱拉线挂点以上斜材受到的冲击作用最大;覆冰断导线工况下单柱拉线塔动态响应大于未覆冰断导线工况,断导线工况下单柱拉线塔动态响应大于断地线工况;本文所研究单档导线脱冰工况下,单柱拉线塔的变形并不大,主柱主、斜材脱冰峰值应力也较小,远小于角钢材料的屈服极限,单柱拉线塔仍非常安全;整相相导线断线工况下,单柱拉线塔受到的冲击作用较单档导线整档脱冰工况大很多,尤其是主柱拉线挂点以上斜材的峰值应力很大,甚至大于主材的峰值应力,整相导线断线工况下拉线挂点以上斜材处于比较危险的状态。
[Abstract]:Different from the self-supporting transmission tower, the first mode of UHV single column cable tower is torsional vibration. Under strong torsional excitation caused by deicing or broken wire, the single column cable tower may produce large torsional vibration. The dynamic response of UHV single column tower excited by deicing or broken wire torsion is worth studying. The main contents of this paper are as follows: firstly, a simplified finite element model of UHV single column cable tower system is established. The correctness of the simplified model of the tower line system is proved by comparing the modal analysis with the fully accurate finite element model, and the ice-coated finite element model of the tower line system is established on the basis of the simplified model of the tower line system. The accuracy of the ice-coated finite element model of tower line system is verified by theoretical calculation. Secondly, the correctness of the numerical simulation method of deicing of transmission line is verified by comparing with the wire deicing test in literature. The dynamic response characteristics of UHV single column cable tower under strong torsional excitation induced by deicing are analyzed, and the effect of changing the initial stress of pull wire on the dynamic response of order column cable tower excited by strong torsion induced by deicing is studied. The validity of the numerical simulation method of transmission line breakage is verified by comparing it with the wire breakage test in the literature. The dynamic response of the order column cable tower under three working conditions is analyzed. The results show that under the action of deicing and strong torsional excitation caused by broken wire, the main column above the hanging point of single pillar pull wire Tara line produces torsional deformation. The main column under the cable hanging point produces rigid body rotation with the section of the cable hanging point; the oblique material above the main cable hanging point of the main column receives the greatest impact; the dynamic response of the order column drawing tower issued under the condition of ice-covered broken wire is larger than that of the unfrozen conductor. The dynamic response of the tower is larger than that of the ground wire, the deformation of the tower is not large, and the peak stress of deicing is smaller in the main column. Far less than the yield limit of angle steel material, the single column cable tower is still very safe, and under the condition of the breakage of the phase wire, the impact of the single column cable tower is much greater than that of the single stage wire under the whole deicing condition. Especially, the peak stress of the inclined material above the point of suspension of the main column is very large, even greater than the peak stress of the main material. Under the condition of the breakage of the whole phase wire, the inclined material above the point of the tie wire is in a more dangerous state.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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