高海拔地区特高压直流试验线段下的地面合成电场强度特性

Characteristics of Resultant Electric Field Under Ultra High Voltage Direct Current Test Lines in High Altitude Area

为获得高海拔地区特高压直流输电线路的电磁环境特性,为线路设计提供可靠参考,基于海拔2 100m的昆明特高压国家工程实验室的特高压直流试验线段,开展了地面合成电场强度ES的长期统计测试。通过线下多点同步测量,获得了不同工况下ES的横向分布。基于标准工况下的长期统计测试结果,获得了ES的累积概率分布。通过改变导线最小对地高度、极间距、分裂间距等线路参数,获得了其对ES分布的影响规律;并分析了电压和极性对ES幅值及横向分布的影响规律。测试结果表明:1)额定工况下,ES横向分布的极值出现在加压极导线对地投影附近,且负向极值比正向极值大。单极电压下的极值位置比双极电压下更靠近相应加压极导线。2)额定工况下,春季ES正向极值的50%统计值为19.10kV/m,负向为-25.00kV/m;秋季则分别为23.10kV/m和-21.50kV/m。3)随着导线最小对地高度、极间距及分裂半径的增大,ES减小;分裂半径在0.35～0.50m范围内变化对ES的影响不明显。4)ES幅值随着导线电压单调增大,单极电压下ES的增长率和双极电压下基本一致。

In order to obtain characteristics of electromagnetic environment （EME） around UHVDC transmission lines and to provide reliable intelligent support for power line designing, we performed long-term statistical measurements of resultant electric field （Es） on the UHVDC test lines located in National Laboratory for UHV Technology in Kunming, China. The lateral distribution of Es was obtained through synchronous measurements at multiple points under the test lines, and the cumulative probability distribution of Es was acquired based on the results of long-term statistical tests under standard condition. By changing minimum conductor height, pole spacing, and bundle radius, the influences of the line parameters on Es were obtained. Furthermore, the effects of line voltage and polarity on the magnitude and distribution of Es were studied. Conclusions can be drawn that, 1 ） under the regular operating condition, peak values of Es appear at the projection of energized poles, while the negative extremum is larger than the positive one. Compared with bipolar situation, the position where extremum shows is closer to the voltage injecting pole in mono-polar situation; 2} in spring, the statistical 50~//oo value of the positive extremum of Es is 19.10 kV/m, while for the negative extremum, it is --25.00 kV/m, however, in fall, these two values are 23.10 kV/m and --21.50 kV/m, respectively, both larger than those in spring; 31 as the minimum conductor height, pole spacing, and bundle radius increase, the magnitude of Es decreases; 4） the magnitude of Es increases monotonously with the voltage applied on the conductors, and the increasing speeds of bipolar and mono-polar conditions are quite close to each other.