| Since the reform and opening up,China’s economy has continued to develop at a high speed,people’s demand for electric power is increasing day by day,and the voltage levels of high-voltage and ultra-high-voltage transmission lines continue to increase.The transmission tower-line system is a long-span and high-rise structural system.When crossing the valley landform with large terrain difference,large height difference between adjacent towers of the transmission line will occur.Under the wind load,the transmission line is prone to form strong wind-induced response.Serious accidents will also lead to tower fall,resulting in shutdown of the whole line.Therefore,it is of great practical significance to study the response of transmission tower-line system under complex wind loads.In this paper,a 500kv transmission tower-line system with large height difference is taken as the prototype,and the finite element numerical simulation time domain analysis method is used to analyze the wind vibration response of the transmission tower-line system.Based on the similarity principle and condensation theory,the Aeroelastic model of transmission tower-line system is designed and built,and the laboratory wind tunnel test is carried out and compared with the finite element analysis results for verification.The main work is as follows:(1)The composition of pulsating wind and its basic characteristics such as turbulence intensity are introduced,and the action forms of wind load on transmission lines are expounded.On the basis of referring to domestic and foreign scholars’ research on wind load simulation,this paper,based on AR Autoregressive model in linear filtering method,uses davenport fluctuating wind speed spectrum,and uses MATLAB program to simulate and generate fluctuating wind speed time-history curve acting on conductor.The wind load time history curve is obtained by combining the wind load calculation formula acting on the transmission tower and the conductor.(2)Considering the non-linearity of the transmission line and the coupling of the tower-line system,the appropriate finite element unit is selected and the coupling model of the transmission tower-line system is established in ANSYS.Based on the time-history analysis theory,the transient dynamic analysis of the transmission tower-line system is carried out in the time domain,and the influences of wind speed,wind direction angle and suspension point height on the wind-induced vibration response of the tower-line system are explored.(3)Based on the similarity principle and the theory of conductor condensation,the Aeroelastic model of one tower and two spans transmission tower-line system with large height difference is designed and built.Wind tunnel tests were carried out in the wind tunnel under multiple working conditions and different height differences.The acceleration sensor and diem digital image correlation technology were used to collect and process the data.the response of the transmission tower and conductor under wind load in this type of transmission tower-line system was investigated and compared with the finite element analysis results.(4)The finite element model of jumper wire,a special conductor in tower-line system,is established by ANSYS,and the finite element wind vibration response analysis is carried out.The influence of different wind speeds,different wind direction angles and the installation of suspension insulator strings on the wind deflection characteristics of jumper wire is studied,so as to guide the reasonable arrangement of jumper wire and reduce flashover trip accidents caused by wind deflection.In this paper,the wind tunnel test of Aeroelastic model combined with finite element theoretical analysis is mainly used to explore the wind vibration response of transmission tower-line system with large height difference under complex turbulent wind field. |
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