特高压变电站设备体系地震下的耦联振动与抗震性能研究

Substation apparatuses are generally interconnected by busbars and can be thought as a coupled system. Current seismic analysis focuses on the seismic performance of individual equipment and the influence of busbars is not fully considered. The coupling vibration of busbars and equipment is one of the main causes of equipment failures, according to earthquake damage investigations. As ultra-high voltage (UHV) substation equipment, which is characterized by extreme height and flexibility, can generate large displacement at the top, busbars between the UHV equipment are more prone to being detrimental to equipment. This project studies the coupling vibration and seismic performance analysis method of the equipment system under seismic actions in UHV substations. Based on modified chained- beam- constrained model (CBCM) and considering the impact of spacers in busbars, mechanical models of various types of busbars will be established. Besides, considering the dynamic coupling effect between equipment and busbars, theoretical analysis model and vibration equation of coupled equipment system will be developed. The highly coupled nonlinear vibration equation is equivalently linearized to decouple the equipment and the busbars. In addition, the characteristic of seismic responses of the coupled equipment system with various busbar parameters and the dynamic characteristics of equipment will be investigated. By using the shaking table test and the finite element analysis of full-scale coupled equipment system, the seismic performance of UHV coupled equipment system will be systematically studied. Finally, the seismic analysis and design method for the UHV equipment system will be proposed considering the coupling effect and using the theoretical analysis model.

变电站设备之间通常采用母线连接组成耦联体系，目前抗震分析中主要考核单体设备的抗震性能，未充分考虑母线的影响。而震害调查表明，地震作用下母线与设备的耦联振动是造成变电站设备破坏的主要原因之一。特高压设备具有高、柔的结构特征，顶部位移较大，母线更容易对设备造成不利影响。本项目研究地震作用下特高压变电站设备体系的耦联振动与抗震性能分析方法。在考虑母线间隔棒影响的情况下，基于修正的链式梁约束模型，建立不同类型母线的力学模型。考虑设备与母线的动力耦联作用，建立设备耦联体系的理论分析模型及振动控制方程。对高度耦合的非线性振动控制方程进行等价线性化以解耦求解，研究不同母线参数、设备动力特性下的耦联体系地震响应特性。通过足尺设备耦联体系振动台试验及精细化有限元分析，研究特高压设备耦联体系抗震性能，结合理论分析模型，提出考虑耦联作用的特高压设备体系的抗震分析及设计方法。

本项目经过四年的研究，主要取得的结果包括：.（1）目前对变电站用分裂导线的力学性能及分裂导线连接的电气设备耦联体系的地震响应特征及抗震设计方法的研究尚未透彻。本项目研究建立了支柱类电气设备的动力模型、分裂导线的力学模型及耦联体系的动力学模型，并对分裂导线连接的电气设备耦联体系进行了振动台试验，归纳总结出了分裂导线连接的耦联体系的抗震设计方法。.（2）针对特高压直流工程抗震问题，国内外对于特高压悬吊式换流阀的抗震性能还缺乏深入研究。本项目研究基于典型的多层悬吊式换流阀结构，对换流阀的地震响应进行研究，并提出有效的减振控制方案和抗震设计方法。.（3）针对变电站大量设备存在的相互之间的弱耦联作用，目前的研究未揭示弱耦联现象的形成机理并形成系统性理论，常规的建筑抗震计算分析方法在处理弱耦联问题时又存在明显局限性。鉴于此，本项目从试验研究出发，对弱耦联作用的形成机理进行了深入探讨，并基于隔离分析与等价线性化思想建立了弱耦联体系理论分析框架的基本主体，对弱耦联问题形成了定性与定量的双重定义。