1000kV构架风振系数的计算研究

Calculation and Study For Wind-induced Vibration Coefficient of 1 000 kV Structural Gantry

1000kV变电构架高度高,荷载大,结构重要性高,采用钢管格构式结构,自振周期大,属高柔结构,在风荷载作用下的动力响应相当显著。基于Matlab,采用Davenport风速谱对大气边界层的脉动风速进行模拟,并将风荷载作用于构架上,使用Ansys分析1000kV构架的风振响应。根据风振系数的定义,在风振响应计算结果的基础上,对1000kV构架各分段的风振系数进行了计算,并与基于相关规范的设计取值进行了比较。计算结果表明,构架x向与y向的风振响应并不完全相同,通过理论计算所得的风振系数并不与高度完全成比例,x向风振系数在构架横梁处存在较大的突变。杆件内力计算结果表明,只要取值合理,构架设计时,格构式部分可沿全高取统一风振系数,与根据各分段实际风振系数计算所得杆件内力的误差并不大。

The 1 000 kV structural gantry is a high and heavy load steel latticed structure,which is of vital importance in the 1 000 kV electric substation.The 1 000 kV structural gantry is a tall and slender structure and of high natural vibration period,therefore,its dynamic response under the action of wind load is very significant.This paper describes the simulation of the fluctuating wind speed in atmospheric boundary layer in Matlab by adapting the Davenport spectrum.The 1 000 kV structural gantry＇s wind-induced response is analyzed in Ansys software on the premise that the wind is loaded on the structure.Then the wind-induced vibration coefficient is calculated on each subsection of the 1 000 kV structural gantry and compared with the design value based on the related regulations.The calculation results show that the wind-induced response of the 1 000 kV structural gantry in x direction is not exactly the same as that in y direction.The wind-induced vibration coefficient,which is obtained from the theoretical calculation,is not proportional to the height.The x direction wind-induced vibration coefficient mutated at the cross beam position.The member force calculation indicates that it is feasible to use a unified wind-induced vibration coefficient along the latticed section＇s full height in the design of 1 000 kV structural gantry.The result is not different from the member force calculation based on the actual wind-induced vibration coefficient on each subsection.