强对流环境下输电塔线体系的振动耦合响应与可靠性分析

Vibration Coupling Response and Reliability Analysis of Transmission Tower-Line System in Severe Convective Environment

为提高输电线路的安全性和对恶劣天气的抵抗能力,考虑了强对流环境的高湍流、强脉动特性,基于有限元时程分析方法,分析了强对流环境下输电塔线体系的振动耦合特性,评估了输电塔线体系的可靠性。以2021年浙江省舟山市一处110 kV猫头塔倒塔事故为研究背景。基于脉动风载荷研究了输电塔主材轴力的时空分布规律,研究了强对流脉动风载荷的脉动放大作用;分析了强对流环境下导地线的线条风载荷对主材轴力的影响作用;考虑了脉动放大作用,研究了输电塔主材构件的受压强度和稳定性。结果显示,地导线的线条风载荷贡献率最高可达60.02%,考虑了脉动放大作用后,强对流脉动风的脉动放大比超过了2倍。这也是输电塔在强对流脉动风下容易发生倒塔的原因:主材会在强对流脉动风的放大作用下受压失稳,进而折损倒塔。该研究为对浙江省及其他沿海地区输电塔线体系的抗风设计提供技术支撑。

To improve the safety of transmission lines and the resistance to severe weather,considering the high turbulence and strong pulsation characteristics of the severe convection environment,the vibration coupling characteristics of the transmission tower-line systems in the severe convection environment were analyzed based on the finite element time history analysis method,and the reliability of the transmission tower-line system was evaluated.The research background was a 110 kV cat head tower collapse accident in Zhoushan City,Zhejiang Province in 2021.Based on the pulsating wind load,the temporal and spatial distribution law of the axial force of the main material of the transmission tower was studied,and the pulsating amplification effect of the severe convective pulsating wind load was studied;the influence of the linear wind load of the ground wire on the axial force of the main material under the severe convection environment was analyzed;considering the effect of pulsation amplification,the compressive strength and stability of the main components of the transmission tower were studied.The results show that the linear wind load contribution rate of the ground wire can reach up to 60.02%.After considering the pulsation amplification,the pulsation amplification ratio of the strong convective pulsating wind was more than 2 times.This is also the reason why the transmission tower is prone to collapse under the severe convective pulsating wind:the main material will be compressed and unstable under the amplifying effect of the severe convective pulsating wind,and then the collapsed tower will be damaged.This research provides technical support for the wind-resistant design of transmission tower-line systems in Zhejiang Province and other coastal areas.