输电线断线对高压输电塔-线体系的冲击作用分析

研究了输电线断线对高压输电塔-线体系的冲击作用。给出了断线前后的结构动力平衡方程。分别采用梁单元、杆单元和悬链线单元对输电塔、绝缘子和输电线进行了模拟。根据实际工程,考虑输电线的几何非线性建立了高压输电塔-线体系的三维有限元模型,并计算了输电塔的动力特性。根据分析方法及分析工况,分别研究了不同工况下断线对高压输电塔-线体系的冲击作用及安全度评定。研究结果表明,地线的断线冲击较小,应该考虑不同的导线断线组合情况;断两根导线的冲击值,接近于设计所取的安全系数;输电线断线对高压输电塔的冲击作用不可忽视。

Analysis of Impact Effect of Power Transmission Tower-line System Subjected to Broken Wire of Transmission Line

The impact effect of power transmission tower-line due to broken wire of transmission line is studied in this paper. Equations of dynamic equilibrium of structure before and after broken wire are given. The tower, the isolator and the transmission line are simulated by the beam element, truss element and catenary cable element, respectively. Considering the geometric nonlinearity of transmission line, the three-dimensional finite element model of the power transmis- sion tower-line system is created based on a practical engineering and the dynamic characteristics of tower are calculated. Based on analysis method and cases, the impact effects of power transmission tower-line system under different cases of broken wire are researched, respectively. The results show that the impact effect of ground line is very small, and different combinations of broken wire of the conductor should be considered. The impact value under broken wire of two conductors is close to the safety factor of design. So the impact effect of power transmission tower subjected to broken wire can not be ignored.