Radio Interference and Audible Noise of the UHVDC test line under high altitude condition

Electromagnetic environment (EME) is one of the key issues of UHVDC power transmission projects. This paper presents the installations, methods and calibrations of Radio Interference (RI) and Audible Noise (AN) under the UHVDC test lines in National Laboratory for UHV Technology located in Kunming, with a concerning altitude of 2100 m. Measurement results including statistical values, lateral profiles, RI spectrums, variation with voltage and relative humidity influence are illustrated. Comparisons with various empirical calculation methods revealed before are performed and demonstrate none of them can provide acceptable predicting results under high altitude condition.