In order to study the electromagnetic environment（EME） characteristics

prediction

and protection of UHVDC transmission line in high altitude area

in Kunming UHV national engineering laboratory

first

we established an EME testing platform of UHVDC transmission line in high altitude area

and obtained EME characteristics during experimental studies for six years.Then

we derived the altitude correction factors of the audible noise of 1 d B/1 000 m and radio interference of 4.3 dB/1 000 m

and put forward a prediction formula of radio interference strength and audible noise considering meteorological parameters.Finally

we measured the EME of the ±800 kV Chu-Sui DC transmission line for contrast

and proposed the drainage shielding methods to reduce the maximum of ground electric field strength to 50%.