文档介绍：重冰区超高压输电塔线体系安全性研究
重庆大学硕士学位论文
Study on Safety of EHV Transmission Tower-line System in Heavy Icing Area
A Thesis Submitted to Chongqing University
in Partial Fulfillment of the Requirement for the
Degree of Master of Engineering
By
Haoyue Cheng
Supervised by Prof. Bo Yan
Major: Solid Mechanics
College of Resource& Environment Science of Chongqing University, Chongqing, China
April, 2011
摘要
500kV超高压输电技术已广泛应用于电力传输系统。超高压输电塔线体系具有塔体结构高和跨度大的特点,其对覆冰及风荷载作用的响应十分敏感,严重时会发生断线和倒塔事故,影响输电线路的安全运行。因此对重冰区超高压塔线体系的安全性研究具有重要的工程实用价值。
本论文以500kV重冰区超高压输电线路为研究对象,采用数值方法对塔线体系在重冰、脱冰、断线情况下的安全性进行较全面的研究。首先利用ABAQUS有限元软件建立包括输电杆塔、导地线、绝缘子、线夹和间隔棒在内的典型三档两塔精细有限元模型,通过采用等效密度和等效加速度的方法模拟塔线体系的覆冰荷载和导地线的脱冰荷载。数值计算得到塔线耦合体系在自重及典型重冰情况下的应力分布;模拟得到在脱冰以及风和脱冰组合工况下的动力响应,得到杆塔、导地线等的运动和应力时程,进而分析研究塔线体系的安全性。然后通过定义单元的“死”与“活”,模拟输电导地线的断裂,进而模拟塔线体系在断线事故下的动力响应,并塔线体系除断裂导地线外其余构件的安全性进行研究。根据我国现行输电线路杆塔设计规程及IEC标准,对杆塔的安全性进行分析,进而通过与数值模拟结果的比较,指出现行设计规程中对断线工况的简化计算方法可能存在不足,并建议引入冲击动力系数考虑断线对杆塔的冲击效应。最后,给出杆塔杆件的破坏准则,模拟塔线体系在导地线断线时,塔线体系的破坏过程。
本论文研究工作及其结果对500kV超高压输电线路杆塔设计具有重要的参考价值。
关键词:超高压输电线路,塔线耦合体系,数值模拟,安全性。
ABSTRACT
500kV Extra-high Voltage (EHV) transmission technology has been widely used in power transmission system. Due to its characteristics of high tower and long span, the EHV transmission line is sensitive to ice and wind loads, which in extreme cases lead to breakage of conductor line and collapsing of tower. The Investigation on safety of transmission line in heavy icing area is very important for the safe operation of power supply system.
The dynamic responses of typical sections of 500 kV transmission tower-line system in heavy icing area after ice-shedding and wire-broken are numerically prehensively in this thesis. Firstly, the finite element models, including transmission towers, conductor lines, ground wires, insulators and spacers, of the transmission tower-line system are created in ABAQUS/CAE. The static load generated by the weight of the ice accreted on the transmission tower-line system and the dynamic loads