双回特高压交流输电线路电场沿高度的非单调变化特性分析

Analysis on Characteristic of Spatial Electric Field Intensity Non-Monotonically Varying Along Height of Double-Circuit UHV AC Transmission Lines

采用模拟电荷法,计算了三维特高压交流双回输电线路模型在6种相序布置下的空间电场强度分布。通过分析空间电场强度的分布特性发现,对于同塔双回输电线路,采用不同相序布置时,在线路档距中央垂直于地面的对称轴线上某一点的电场强度值基本不变;并且,采用不同相序布置时,沿高度方向空间电场变化的单调特性不同,即电场强度随高度增加或减小。由此提出了对于需要降低空间不同位置电场强度的问题,应选择不同相序布置的思想;并根据不同相序空间电场强度的分布特性,给出了选择最优相序的方法。文中计算结果对于线路交叉跨越等需要降低空间电场强度的问题具有参考意义。

Utilizing charge simulation method,the spatial electric field intensity distributions of three-dimensional double-circuit UHVAC transmission line model under six different phase sequence arrangements were calculated.Through analyzing the distribution characteristics of spatial electric field intensity it was found that for double-circuit transmission lines on the same tower,the electric field intensity basically kept invariant at a certain point on symmetric axis located in the middle of the transmission span under different phase sequence arrangements.Besides,when different phase sequence arrangements were adopted,the corresponding monotone characteristics of spatial electric field varying along the height direction were different,i.e.,the electric field intensity decreased or increased with the increase of the height.From this,an idea was put forward that for the occasion that the electric field intensity at different spatial position had to be decreased,different phase sequence arrangement should be chosen,and according to the distribution characteristics of electric field intensity in different phase sequence space a method of choosing optimal phase sequence was given.Calculation results of this paper were available for reference to the problem of decreasing spatial electric field intensity due to crossing-over of transmission lines.