【摘要】 由于软母线的牵拉作用,强地震作用下软母线连接的变电站设备将产生强烈的相互作用。将变电站设备简化为具有一定抗侧移刚度的单自由度体系,软母线简化为变刚度的弹簧,并根据悬索理论求得变刚度弹簧的等效刚度,建立了软母线连接电气设备耦联体系单跨结构的动力学模型,采用Newmark-β法结合牛顿迭代对其进行数值求解。通过对其结构特征以及设备参数的分析发现:软母线中张力刚度随水平跨度呈非线性增长,耦联体系的特征频率受单体设备的自振频率、质量比值及软母线等效刚度的影响。在地震作用下,存在一个关键垂跨比,当软母线的垂跨比小于此关键垂跨比时,母线中产生的水平拉力较大,且设备的地震响应受设备的频率比影响较大。在进行软母线连接的变电站设备的抗震设计时,必须考虑关键垂跨比的影响。更多还原

【Abstract】 Because of the pull effect of flexible bus,strong interaction exists in substation equipment interconnected by flexible bus during severe earthquake. The substation equipment was simplified as a single degree of freedom system with lateral stiffness,and the flexible bus was simplified as a spring with variable stiffness. The effective stiffness of the spring was obtained according to the suspension theory. Then a kinetic model of single span structure was built for the electrical coupling equipment interconnected by flexible bus,and solved by using the Newmark-β method combined with Newton iteration. Through the analysis of the structural features and equipment parameters,it shows that the tension stiffness of flexible bus has a nonlinear growth with horizontal span,and the characteristic frequency of coupling system is influenced by the natural frequency of standalong equipment,the quality ratio and the effective stiffness of flexible bus. It is found that there is a critical rise-span ratio under seismic action. When the rise-span ratio of flexible bus is smaller than the critical ratio,large tension generates in the bus,and the seismic response of equipment is greatly influenced by equipment frequency. So during the seismic design of substation equipment interconnected by flexible bus,the influence of critical risespan ratio must be considered.更多还原