| The transmission tower line system is the most common structure in the mountainous terrain,and the change of the mountain wind field has a great impact on the safe operation of the transmission line.From the perspective of the design of the transmission line itself,the current norms in my country are that the tower and the line are designed independently,but the actual situation is that there is a coupling effect between the two.The tower-line coupling effect and failure mode under micro-topography are still unclear,which is a major factor leading to wind-induced collapse of transmission towers.This also makes the safe operation of transmission lines have many security risks.Therefore,it is of great significance to propose tower-line coupling and failure modes under micro-topography.Micro-topography refers to the local narrow special terrain under the large terrain.When the wind flows through the area,it will be affected by the complex mountainous terrain and will have an acceleration effect,which will lead to an increase in the wind pressure on the transmission tower line system built here.Therefore,famous scholars at home and abroad have proposed wind pressure correction coefficients for mountain topography to correct the wind pressure of mountain wind fields.Through data collection,we understand the characteristics of wind field under micro-topography,analyze and compare the wind pressure adjustment formula for mountain wind field under the mountain wind field by national regulations and famous scholars at home and abroad.Summarize the wind pressure adjustment formula suitable for the research object of this paper.It provides a basis for the load input of the dynamic response of the transmission tower-line system under the micro-topography.The tower-line coupled system and the non-coupling system model are established by ANSYS.The non-coupling system model does not consider the coupling effect between the transmission line and the transmission tower.In the finite element model of the towerline coupling system,separation of transmission towers and transmission lines,the connection between the upper end of the insulator and the transmission tower is changed to a hinge support,and the wind load on the transmission line and its own gravity are applied to the transmission tower in the form of node force.The coupling effect of transmission towers under different working conditions is studied.For a single mountain,this paper studies the influence of different slopes and wind direction angles on the coupling effect of the tower-line system.The similarities and differences of the wind-induced responses of the two systems under different mountain slopes were analyzed by finite element calculation.Through comparative analysis,it can be seen that the wind-induced response of the transmission towers in the uncoupled system is larger than that in the coupled system,and with the increase of the slope,the windinduced responses of the transmission towers in the two systems continue to increase.The difference between the wind-induced responses of the transmission towers in the two systems is also increasing.The finite element analysis of the coupling effect of the transmission tower-line system under different wind direction angles shows that the windinduced response of the transmission tower in the y-direction wind field（in the direction of the conductor）is smaller than that in the x-direction wind field（in the direction perpendicular to the conductor）,but the two systems The difference in the wind-induced response of the transmission tower is larger than that of the x-direction wind field.The stability of the transmission tower under different working conditions in a single mountain is analyzed,and the results show that,in the x-direction wind field with high mountain slope,the uncoupled transmission tower is more prone to instability failure and tower top stiffness failure at the inversion point.For Shuangshan,this paper analyzes the influence of different spans and wind speeds on the coupling effect of the tower-line system through finite element calculation.Through comparative analysis,it can be seen that under different spans of Shuangshan,the windinduced response of the transmission tower in the uncoupled system is greater than that in the coupled system,and as the span increases,the wind-induced responses of the transmission towers of the two systems are increasing,and the difference between the wind-induced responses of the transmission towers of the two systems is also increasing.The coupling effect of the transmission tower-line system under different wind speeds is analyzed by finite element analysis.The results show that: with the increase of wind speed,the wind-induced responses of the transmission towers of the two systems continue to increase,and the difference between the wind-induced responses of the transmission towers of the two systems is also growing.The stability of the transmission tower under different working conditions in Shuangshan is analyzed,and the results show that uncoupled transmission towers are more prone to instability failure and tower top stiffness failure at the inversion point when the wind speed and span are large.Figure [83];table [85];reference [93]... |
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