雾对高压直流输电线路离子流场的影响

Effects of Fog on Ion Flow Field Under HVDC Transmission Lines

合成电场和离子流密度是高压直流输电线路的2个重要电磁环境指标,在线路运行中其应满足相应的电磁环境保护要求。当线路穿越雾区,其离子流场效应可能更为突出。该文分析了雾对高压直流线路离子流场的影响机理,提出一种考虑雾的影响作用的离子流场计算方法,以向家坝上海±800kV特高压直流线路为例,研究了雾对离子流场的影响规律。结果表明,地面合成电场随雾的浓度的增高而显著增大,并且雾的浓度越高地面合成电场越大,而离子流密度却几乎不变。与好天气时相比,重雾天气时地面合成电场最大值增加了约45%。

Total electric field strength and ion current density are considered as two of principal environment indices of HVDC transmission lines, and should meet the electromagnetic environment requirement during operating. When the power lines pass the fog zone, the ion flow field will become more severe. In this paper, the mechanism of the effects of fog on ion flow field was analyzed, and an approach calculated the ion flow field with fog was presented. In the case of Xiangiiaba--Shanghai ±800kV UHVDC power lines, the effect regularity of fog on ion flow field was researched, and the analysis results show that the total electric field strength near ground increased observably with the increasing of fog density, and the higher density of fog, the greater the total electric field strength, while the ion current density keep invariant basically. Compare with the value under fair weather condition, the total electric field strength increase about 45% under serious fog condition.