Finite Element Analysis For Static Balance And Dynamic Response Of Transmission Lines

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.