±800 kV直流输电等效干扰电流指标分析

Analysis on Limitation Values of Equivalent Interference Current Caused by ±800 kV UHVDC Transmission System

我国现有特高压直流输电工程均以输电线路等效干扰电流Ieq作为直流滤波性能的衡量指标。文章分析了输电线路等效干扰电流值对周围通信回路的影响,结合对多个直流输电工程中输电线与通信线路的相对位置的调查结果,指出:对于特高压输电线路,如果放宽直流滤波性能指标,将Ieq限制在2200～3500mA范围内,并采用4.5mV作为干扰影响杂音电动势的控制标准,那么输电线与邻近的通信线路的间距应大于500m,在电力建设方面投入的改造费用增加不大;如果采用1mV作为杂音电动势的控制标准,改造费用将明显增加。

At present, the equivalent disturbing current leq of transmission line is taken as the index to judge DC filter effect for UHVDC power transmission projects in China. In this paper, the author analyzes the impacts of equivalent disturbing current caused by transmission lines on surrounding communication lines. Based on the investigation results of relative positions between transmission lines and communication lines in several HVDC＇power transmission projects, it is pointed out that if the DC filter effect index is relaxed and the value of equivalent disturbing current is specified inside the range from 2200 mA to 3500 mA, in that case the spacing between transmission line and adjacent communication line should be longer than 500 m, thus the innovation cost for electric power construction will not evidently increase; if lmV is adopted as the control criterion for noise electric motive force, the renovation cost for electric power construction will evidently increase.