500kV姚邵线舞动倒塔事故分析及对策

介绍了2008年1月11日河南500kV姚邵线耐张塔倒塔事故的形成过程,通过现场调查,结合设计、塔材金相试验、力学原理等分析了舞动倒塔的原因,认为线路长时间舞动造成塔材松动、脱落,杆塔强度下降,线路舞动使导线的静态张力增大,舞动的能量沿直线塔传播到耐张塔后无法向前传播,使耐张塔受到的舞动能量冲击更严重,最终导致耐张塔在舞动的冲击下倒塔。推荐采用可扭转式间隔棒加双摆防舞器,可扭转式间隔棒可以消除或减小导线不均匀覆冰,双摆防舞器可以降低舞动强度,抑制舞动。对防松作用差的防盗装置(防盗螺栓),应进一步采取防松措施(如加装扣紧螺母);今后新建线路应调研线路走径情况,视舞动强度适当提高杆塔、金具、绝缘子等的设计强度,提高金具的耐磨性和螺丝的防松性,在综合经济技术分析后确定线路抗舞动能力。

Cause of Conductor Galloping Tower Collapse at Yaoshao 500 kV Transmission Line

The process of strain tower collapse of 500 kV Yaoshao transmission line,Henan,on 11 Jan,2008.Causes of conductor galloping and tower collapse were analyzed through site investigation,design and mechanics evaluation,and metallographic test,which are attributed to suctained line galloping leading to material loose and even falling as well as tower strength declining.Conductor galloping led the increase of the static tension load on the conductor,and the galloping energy,spreading along beeline,stopped at the strain tower,making the more severe galloping impact on it and ultimately resulting to its collapse.It is suggested to use torsional spacer for reducing or eliminating uneven icing with dual-swing damper for reducing galloping strength.For bolts with less loosing-proof function,additional loosing-proof measures(such as additional working nut).For futher new transmission line it is necessary to investigate the line approach,appropriately enhance design strength for towers,fitting and insulators,abrasion resistance of fitting and loosing-resistance of fixing bults depending on galloping intensity and to determine the anti-galloping capability of line based on synthetic economic technical evaluation.