【作者】 王丽新；

【导师】 杨文兵；

【作者基本信息】 华中科技大学 ， 固体力学， 2004， 硕士

【摘要】 输电导线的舞动是一个国际上普遍关心的科技难题,随着电力建设的发展,大跨度输电线路不断增加,输电线路舞动引起的线路故障所造成的危害越来越严重,经常发生跳闸、断线甚至拉断塔架等事故,对电力系统构成极大的威胁,如何预知和控制舞动也是目前国内外电力部门非常关心的一个问题。本文的目的,就是通过计算机来分析舞动的过程,模拟防舞装置的影响,为电力部门采取防舞措施提供有力依据。本文首先根据非线性有限元理论推导了几何非线性条件下梁单元的刚度矩阵,并针对梁单元的几何特性,选用动坐标迭代法作为非线性计算的基本迭代方法。根据导线结构的非线性特点,采用了收敛因子来调整迭代过程。在导线静悬垂计算中,可根据设计张力自动调整初始条件,使得计算结果满足实际要求。在动力计算即舞动计算中,采用Newmark法直接积分,并在计算过程中自动调整时间步长以保证收敛。同时考虑到相邻档距中导线张力对舞动的影响,并在动载中计入了导线间的磁场力,分析其对舞动的影响,还包括了在导线上加挂防舞装置的设计。借助上述研究编写了有限元程序,并与Ansys进行静力结果的对比,于文献中舞动算例比较舞动结果,误差均满足要求。在此基础上,调整风速、攻角等初始条件以及导线分裂数,通过计算机模拟找出其于舞动之间的内在联系,并验证了舞动的机理以及防舞装置对舞动的影响,所得结果对输电线路舞动的防治具有很好的参考价值。更多还原

【Abstract】 The galloping of transmission line is a hard problem, which has been paid great attention to in the world. Along with the development of construction of electric power, the great span transmission line of electricity increases constantly. The harm caused by the galloping of transmission line has been more and more serious. It can lead a trip, or break the line, even destroy the transmission tower. This took great threat to system of electric. How to predict and control the galloping is also a current problem cared by the electric department.This paper derive the stiffness matrix of the beam element according to the non-linear finite element theory at first, and select the iteration method with moving coordinates for non-linear calculating base on the geometry characteristics of the beam element. According to the non-linear characteristic of the transmission line, this paper used the convergence factor to adjust the course of iteration. While calculating the curve of the transmission line under static load,this procedure can adjust the initial condition automatically according to the designing tension to make the result of calculation satisfy the actual request. Newmark method is used to in the dynamic analyses, and automatically adjust time step in order to guarantee the convergence in the course of calculating. At the same time, considering the influence on the galloping caused by the tension of the transmission line in the next line. Add the power of magnetic field in the dynamical load to analyze the influence to the galloping. The design of equipment to prevent the gallop is also included in the program.A finite element program was written base on the study mentioned above. Comparing the static result with Ansys and the galloping result with the date in the literature shows that the error all satisfies the request. Regulate the number of span and some initial condition such like wind speed, angle of attack to find the relation with gallop by simulated with computer. This program verifies the mechanism of gallop and the influence of the equipment to prevent the gallop. All the result calculated by this program have great help to prevent the gallop of transmission line.更多还原