山地输电线路覆冰拆线动力冲击效应研究

Research on Dynamic Shocking Effects of Iced Transmission Tower-line Systems in Mountain Areas Under Removal of Ground Wire

首先建立了山区输电塔线体系的多塔多线有限元分析模型。基于覆冰荷载模型建立了输电塔线体系的动力分析方法。进一步建立了塔线体系的覆冰拆线动力冲击效应分析方法和动力响应迭代计算方法。以南方某重覆冰山区的实际三塔四线输电线路为工程背景,研究了覆冰后拆除地线下塔线体系动力冲击效应的特点。结果表明:覆冰后进行拆除地线的操作将在输电塔线体系中引起较为显著的动力冲击效应。覆冰弃线对其它相邻地线和导线承载力的影响很小,因此弃线保塔方法仅仅影响所处理的输电杆塔的承载力状况。在覆冰弃线过程中,应该尽量缓慢拆线以降低断线的冲击效应。

First,the finite element model of a transmission tower-line system with multi towers and cables was established.Secondly,the dynamic analytical method of the transmission tower-line system was developed based on the icing load model.Then,the dynamic analytical method and response iterative approach of the transmission tower-line system was presented.A real transmission tower-line system with three towers and four groups of lines in the southern icing mountains was taken as an example to investigate the properties of significant dynamic shock effect induced by removal of ground wires.The made observations indicate that there exist obvious dynamic effects after the operation of removing ground wire under icing.The influence of wire removal on the force-bearing capacity of other adjacent wires and conductors is very small.Therefore,the approach of removal wires can only affect the force-bearing capacity of the concerned transmission tower.It is noted that the wires should be removed slowly so as to reduce the shock effects as large as possible.