微气象区500kV输电线路抗冰能力校核分析

摘要

针对覆冰后输电线路及杆塔的受力情况问题,采用传统导线受力计算模型对连续两次发生覆冰跳闸的500 kV 线路进行抗冰能力校核,研究了覆冰跳闸前后导线荷载、线间距离、不平衡张力以及脱冰跳跃幅值的变化情况.通过覆冰荷载模拟实验,结果表明:OPGW 光缆覆冰过载能力低于地线5 mm,且受导电率影响较大;不均匀覆冰后地线的不平衡张力易整体超标,而导线仅在耐张塔两侧超标,且主要受力杆件为耐张塔横担主材;在档距大于550 m 时,脱冰跳跃的相间净空距离即可引起导线间隙放电.%In order to get a knowlege of the force of transmission lines and electric towers after being iced well,traditional calculation model for conductor force was adopted to check the anti-ic-ing ability of a 500 kV line which had tripped twice successively because of icing,and investigate the changes of conductor load,distances between lines,unbalanced force tensile and ice-shedding j ump amplitude before and after the tripping.The result shows that:firstly,the icing overload capacity for OPGW cable is 5 mm lower than that for conducting wire and is greatly effected by conductivity;secondly,in view of being icing unevenly,the unbalanced tensile force for earth wire is likely to be over the standard wholly while that for conducting wire is only over the stand-ard on the two sides of towers,and the main stressed member for towers is arm material;third-ly,when the span is wider than 550 m,discharging will occur within the conductor gaps caused by the ice-shedding j ump inter-phase headroom.