目前，我国已(在)建的±800 kV特高压直流输电线路的极间距离均按不小于22 m设计。综合考虑电磁环境、合成绝缘子串长、空气间隙、V型绝缘子串夹角等因素，探讨极间距进一步缩小的可能性，并对其经济效益进行分析，为后续特高压直流输电线路的设计提供参考。

At present, it is required that the polarity distance of ±800 kV UHV DC transmission lines constructed or constructing is not less than 22 m in our country. In this paper, the possibility of decreasing the polarity distance is discussed by considering electromagnetic environment, length of the composite insulator string, air gap, angle of the V style insulator string and so on. In addition, the economic benefits are analyzed. The results obtained provide references for the design of future UHVDC transmission line.