Research On Wind Load Characteristics And Response Of 1000kV UHV Substation Frame

The 1000 k V UHV(Ultra High Voltage)substation structure has higher height,larger span,and more complex structure,compared with the traditional 220 k V,330 k V,500 k V and 750 k V transmission towers.It has some characteristics such as light weight,high flexibility,small damping,low fundamental frequency,etc.The frame structure will vibrate violently under the action of strong wind,which is a typical wind load sensitive structure.And the relevant design codes don't give the values of the wind load coefficients of the frame structure.Therefore,the research on the wind load characteristics and wind-induced response of the 1000 k V UHV substation frame has important engineering practical significance.In this dissertation,the aerodynamic coefficients and shape factors of the test model are obtained by the high frequency balance force measurement wind tunnel test,investigating the aerodynamic characteristics of the structure.The actual structural wind loads are inversely deduced and applied to the finite element model of the substation frame to calculate the wind-induced response of the structure,based on the results of aerodynamic coefficients.Then it uses the displacement and acceleration response of key nodes to obtain the wind vibration coefficient of the frame structure.The main research works are as follows:(1)Performing high frequency balance force measurement wind tunnel test on the 1000 k V UHV substation frame segment and the overall scaled rigid model under uniform flow,terrain A and terrain B.In order to focus on statistical characteristics and frequency domain characteristics of aerodynamic coefficients time history under different terrains and wind angles,the aerodynamic coefficients of the segment and the overall models are calculated by using the base shear and bending moment measured in the experiment.(2)The shape factors of the segment and the overall structure are calculated from the function relationship between the wind axis and the body axis through the result of the aerodynamic coefficients.This will clarify the influence of wind field conditions and wind direction angles on structural body coefficients,and examine the proportions of the body coefficients of segments and overall structures.Finally,in order to provide suggestions for the value of the shape factors of the structure,comparing the shape factors obtained from the wind tunnel test with the values of the relevant domestic and foreign codes.(3)The vertical wind load distributions of the 1000 k V UHV substation structure are obtained through the aerodynamic coefficient,which are applying to the finite element model and calculating the acceleration and displacement response of the frame structure.There are acceleration and displacement responses time history analysis and statistical comparison of key nodes at different positions of the frame,studying the comparative relationship of wind-induced vibration response under different terrains and wind angles.(4)From the mean and root mean square values of the displacement responses of the key nodes at different positions of the structure,the wind vibration coefficients at different heights of the structure are calculated by the crest factor method.The wind-vibration coefficients at different nodes locations of the framework under different terrains are compared,which provides a reference for the values of the wind-vibration coefficients of the 1000 k V UHV substation framework.