In order to improve the capacity of responding to natural disasters

research on anti-icing ability of DC transmission cross-line in Hunan province which voltage class is above 500kV is conducted

and the field data of insulation configuration combined with ice and pollution area chart of Hunan province is also analyzed. Results show that Binjin line and Jinsu line have about half of insulation which configuration gradient size are above or close reference gradient

and it is recommended that operating the power system with a lower voltage once covered with ice

and the lower voltage is suggested 650kV and 700kV respectively. Conversely

40. 9% of insulation in Fufeng line run the risk of flashover

and the lower voltage is recommended to650kV. Moreover

Jiangcheng line attains a extremely low insulation configuration and has about 69. 4% of insulation which configuration gradient size are above or close reference gradient. As a consequence of this

it should be operated at a lower voltage once iced.