华中科技大学博士学位论文特高压输电线的覆冰舞动及脱冰跳跃研究姓名：夏正春申请学位级别：博士专业：结构工程指导教师：方秦汉;李黎20081009华 中 科 技 大 学 博 士 学 位 论 文华 中 科 技 大 学 博 士 学 位 论 文 I 摘摘 要要 架空输电线的覆冰灾害是一个国际上普遍关心的问题。随着特高压线路的建设，大跨度输电线路不断增加，电线覆冰后的舞动和脱冰跳跃易酿成很大危害，轻则相间闪络、损坏地线和导线、金具及部件，重则线路跳闸停电、断线倒塔等，从而造成重大经济损失。为了保证特高压电网的安全可靠运行，对输电线的防雪灾、冰灾提出了更高的要求，因此有必要对输电线覆冰作用下的特性进行深入的研究。 本文对大跨越输电线路的覆冰作用进行了多方面的研究，主要包括导线非线性有限元模型的建立、初始构形的确定、覆冰导线的空气动力特性 CFD 仿真计算、导线的舞动分析、脱冰跳跃计算等几部分，旨在建立一套输电线在覆冰作用下的舞动及脱冰跳跃的计算方法。本文各个章节都围绕此问题展开。 首先推导了进行输电线非线性有限元分析的两节点杆单元的参数矩阵，给出了用单根导线来等效分裂导线的计算公式，介绍了龙格库塔法进行输电线动力分析的方法，并用 FORTRAN 编写了相应的计算模块。 从单档输电线初始构形的解析方法出发，设计了考虑绝缘子滑轮调整作用的多跨连续档输电线初始构形的迭代求解流程，利用 FORTRAN 编写了连续档输电线线初始构形的迭代子程序。该方法难以适用于复杂的荷载、边界条件下的输电线找形要求，本文提出了在迭代求解自重作用下初始构形的基础上，建立连续档架空输电线的有限元模型，进行非线性有限元求解找形的混合找形法，该方法综合了迭代法和有限元法的优点，找形效率高、收敛速度快，可满足各种悬挂形式、档距布置和边界条件的输电线找形要求。 利用 CFX 数值风洞技术对覆冰导线进行 CFD 数值模拟，计算了覆冰导线在各风攻角下的三分力系数。通过已建立的连续多档导线的空间有限元模型，采用龙格库塔法编程实现了输电线舞动的数值求解，并用 FORTRAN 编写了相应的舞动分析模块。以汉江大跨越覆冰导线为例，进行了导线舞动的仿真计算，计算结果深化了对舞动机理的认识，为进一步研究输电线的防舞方法奠定了基础。 对覆冰导线脱冰的起因和作用机理进行了分析，利用 FORTRAN 自编了覆冰导线脱冰动力响应的计算程序，并通过与某线路的试验实测结果进行对比，验证该程华 中 科 技 大 学 博 士 学 位 论 文华 中 科 技 大 学 博 士 学 位 论 文 II 序的可靠性、有效性。然后用该计算程序对汉江大跨越架空导线的脱冰跳跃进行了仿真计算，总结出了一些有意义的结论。 输电线在覆冰作用下的灾害研究是一个既十分紧迫，又相当复杂；既具有十分重要的社会经济意义，又难于迅速地拿出彻底解决办法的世界性攻关课题。希望本文的研究和分析能够为导线覆冰作用的理论研究提供一条新的思路，为导线覆冰灾害的防治提供更为有效的理论依据。 关键词：输电线；覆冰；初始构形；舞动；脱冰；数值风洞；非线性有限元 华 中 科 技 大 学 博 士 学 位 论 文华 中 科 技 大 学 博 士 学 位 论 文 III Abstract The galloping and ice-shedding of overhead transmission lines is a hard problem, which has been paid great attention to in the world. Along with the development of Ultra-high Voltage(UHV) transmission lines in China, the great span transmission line of electricity increases constantly. The harm caused by the galloping and ice-shedding of overhead conductors has been more and more serious, which can cause wear and fatigue damage to conductors, insulator strings, support hardware and tower components, even break the line and destroy the transmission tower. This result in heavy economic losses. In order to guarantee the safety and reliability of UHV electrical network, the dynamic mechanical properties of power transmission lines under the effect of icing accretion must be studied seriously. In this dissertation, the studies on the effect of icing accretion for long conductors of power transmission lines are performed. The research content includes: nonlinear finite element model of conductors, the determination of initial configuration of overhead lines, simulation calculation of the aerodynamic characteristics of the ice-accreted conductor, calculation and analysis of nonlinear galloping, calculation and analysis of ice-shedding. The primary task of this dissertation is attempting to explore a set of complete method that can be used for galloping analysis and ice-shedding analysis, and all sections of this dissertation are depicted on this aim. This dissertation derive the stiffness matrix and mass matrix of the two-node bar element according to the non-linear finite element theory at first, calculation formula for using single conductor to equal bundle conductors was put forward. Then the dynamic analysis of transmission lines were done by Runge-Kutta Method, and simulation calculation program has been compiled used FORTRAN. On the basis of analytical method of form-finding analysis of single-span power transmission lines, the solution flowchart of iterative computation the initial configuration 华 中 科 技 大 学 博 士 学 位 论 文华 中 科 技 大 学 博 士 学 位 论 文 IV of multi-span power transmission lines is given, which can consider the regulative action of suspension insulator, and a subprogram is compiled to find the initial configuration of multi-span power lines. This method cant satisfy the application requirement of the case with more complex loads and more complex boundary condition. So a new method for form-finding analysis of cable structures is be proposed: the nonlinear finite element model of overhead conductors can be built according to the iterative solving result of initial configuration under the gravity action, then the non-linear FEM method can be used to find the configuration with complex loads and complex boundary conditions. This new method named Mixed form-finding, which integrate the advantages of iterative solving method and FEM method, has higher efficiency, rapid speed of convergence, is more concise and suits for analysis of more complex loads and complex boundary conditions. According to the characteristics of the crescent shape iced conductor models, numerical wind tunnel technology based on CFD numerical simulation is used to study the mean aerodynamic force coefficient of iced conductor at various angles of attack in this dissertation. After the space finite element model of multi-span power transmission lines are built, the Runge-Kutta Method is used to compute the galloping of power transmission lines acted by aerodynamic forces, and the corresponding program for galloping analysis is Compiled. Then the conductors of UHV Han-river long span transmission lines are token as