Dynamic Instability Analysis Of Transmission Tower-Line System Under Downburst

At present, with the national air pollution control action plan“Four Four Straight” started and during the “13.5”,UHV( Ultra High Vacuum)construction accelerated on the basis of “Four Four Straight” engineering, the electric power industry is developing rapidly, and transmission wire tower structure of bearing the delivery of power will also get rapid development. However, Harsh climatic conditions cause the tower to collapse occasionally, but the phenomenon that transmission tower collapses is the most caused by downburst. In China, the strong winds caused by downburst did not be studied too much, the design specifications of the transmission tower used in the atmospheric boundary layer wind,And it has essentially the difference with downburst,So, study the basic characteristics of downbursts and the effect of the wind-resistant design of transmission tower-line and compare with the atmospheric boundary layer wind is very necessary.this paper, simulation of the downburst by matlab, Aiming at the problem of the downburst simulation with empirical values of the fluctuation components, put forward the evolutionary spectrum modified spectral representation method and compare with AR method、modified spectral representation method, and prove the evolutionary spectrum modified spectral representation method.The author simulated the stochastic fluctuating and downburst which can be used in posterior analysis by the modified spectral representation method and evolutionary spectrum modified spectral representation method and transmission tower line system’s different angle under the downburst is analyzed, we found in the 90 degree angle the wire has a great influence on transmission tower. And then, according to the result of modal、nonlinear buckling and the transient analysis, the author researched the static and dynamic stability of a transmission tower by the method-Incremental Dynamic analysis combining with Budiansky-Roth criteria. Discusses the different damage regions on transmission tower on the basis of bearing capacity factor,explain the reason why most of the transmission towers are destroyed is not in the root.