750 kV架空输电线路覆冰跳闸原因及仿真分析

Simulation Analysis of Ice Tripping of 750 kV Overhead Transmission Line

总结并分析了新疆地区几回750 kV输电线路覆冰跳闸原因和整改措施。结合事故调研,利用ANSYS软件对均匀覆冰、三段覆冰、线性覆冰和高悬挂端覆冰工况进行了有限元分析,结果表明,线路覆冰跳闸主要由地线非均匀覆冰导致导、地线局部静态距离不足而引起;比较非均匀覆冰中的三段覆冰、线性覆冰与高悬挂端覆冰,高悬挂端覆冰对弧垂最低点偏移的影响最大,且随覆冰长度的增加,导、地线静态接近距离存在极小值。通过工程实例计算发现,地线高悬挂端覆冰下导地线最小接近距离小于规程规范限定的最小静态距离,并能导致放电跳闸,工程设计中应重视此种情况下的间距校验。

This paper summarizes and analyzes the causes and rectification measures of ice tripping of 750 kV transmission lines in Xinjiang.Combined with accident investigation,finite element analysis is carried out on the conditions of uniform icing,three-stage icing,linear icing and high suspension end icing with ANSYS software.The results show that the ice tripping of line is mainly caused by the insufficient local static distance of guide and ground caused by the non-uniform icing of ground wire.Compared with the three-stage,linear and high-suspended end ice covers,the high-suspended end ice covers have the greatest influence on the lowest point migration of the arc,and with the increase of the length of the ice covers,the static approach distance of the guide and ground wire has a minimum value.Through the calculation of engineering example,it is found that the minimum approach distance of guide ground under the high suspension end of ground ground covered by ice is less than the minimum static distance defined by the specification,and can lead to discharge trip.In this case,attention should be paid to the spacing check in engineering design.