±1200 kV特高压直流穿墙套管抗震性能分析

Seismic Performance Analysis of±1200 kV UHV DC Wall Bushing

为评估特高压穿墙套管的抗震性能,建立了某型1200 kV特高压穿墙套管仿真模型,针对该模型进行了动力特性分析,并通过时程计算方法获取地震下穿墙套管的加速度、位移及应力响应,分析其加速度放大系数以及根部应力峰值。基于结构地震响应研究了谱放大系数曲线及其峰值影响因素,进一步分析了法兰加劲肋和安装板厚度对地震响应的影响。研究表明:在地震波反应谱平台段内,穿墙套管顶部加速度存在明显放大效应,轴向谱加速度放大系数峰值出现在安装板面外变形模态频率附近。法兰加劲肋的设置可有效降低穿墙套管轴向加速度峰值,并减小安装板和法兰根部的应力峰值。随着安装板厚度的增加,穿墙套管轴向加速度峰值和安装板的应力峰值均减小,且随着板厚越大降低幅度逐渐平缓。

For assessing the seismic performance of UHV(ultra⁃high⁃voltage)wall bushing,a simulation model of a specific type of 1200 kV UHV wall bushing is set up.The dynamic characteristics of the model are analyzed,the ac⁃celeration,displacement and stress response of the wall bushing under the seismic are calculated by way of time histo⁃ry calculation method,and the acceleration amplification factor and the peak stress at the bottom are analyzed.Based on the seismic response of the structure,the spectral amplification factor curve and its peak influence factors are investigated.The impact of flange stiffeners and the thickness of the installation plate on seismic response is in⁃vestigated further.The research shows that the acceleration on top of the wall bushing has an obvious amplification ef⁃fect in the platform section of the seismic wave response spectrum.The peak value of the axial spectral acceleration amplification factor appears near at the out⁃of⁃plane deformation modal frequency of the installation plate.The provi⁃sion of flange stiffeners can effectively reduce peak of axial acceleration of the wall bushing and reduce the peak stress of the mounting plate and the bottom of flange.With the increase of the thickness of the installation plate,both the peak of the axial acceleration of the wall bushing and the stress peak of the installation plate decrease,and the bigger the plate thickness is,the more gentle the amplitude decreases.