绝缘子断裂对大跨越输电线路的动力效应

Dynamic effect on long-span transmission line system due to insulator rupture

输电线路中的绝缘子由于外界多种因素作用可能会发生断裂,致使导线跌落,在导线下落过程中将对输电线路产生持续的动力冲击作用.以某大跨越输电塔为例,采用有限元方法建立了塔线模型,并对导线的跌落过程进行模拟.导线在自由跌落过程中存在明显的回弹,动力效应显著,部分杆件如挂线杆将产生较大的峰值应力,关于中轴面对称的杆件将产生摇摆效应.与地面接触的导线在跌落过程中也存在导线回弹现象,构件内力与导线自由跌落时相差不多.从能量角度解析了这两种导线跌落过程,并通过对比验证了导线跌落模拟的准确性.

The insulator on transmission line may rupture due to multiple exterior actions, resulting in dropping of conduct. During the conduct dropping process, the transmission tower line system will receive continuous dynamic impacts. Taking a long-span transmission tower as example, finite element method was employed to construct a tower-line model and simulate the conduct dropping process. In the process of free dropping, the conduct rebounds, and part of structural members such as tilted-braced members expose to high peak stresses. And two structural members symmetrical to the central axis plane behave as swaying effect. The rebound of conduct and similar stresses on the structural components are also found during the conduct dropping process after considering the impinging action between conduct and ground. The two dropping processes were also studied comparatively from view of energy, and the simulation methods of the two dropping processes were verified.