Study on the minimum polarity distance of suspension tower for UHVDV transmission line in ultrahigh altitude area

The design experience of ± 800 kV UHVDC transmission line in 3500 m and above is less. Based on the basic design conditions of ± 800 kV DC transmission line project, the minimum polarity distance of the suspension tower in an ultrahigh altitude area is investigated and the effects of the electromagnetic environment, insulator string length, V-string angle string and air gap on polarity distance are analyzed. Finally, the minimum polarity distance of the suspension towers under different altitudes, V-string angle string and icing area conditions are calculated, which provides technical support for the tower design of UHVDC transmission lines in ultrahigh altitude areas.