Audible noise spectrum characteristics of positive and negative wire in UHV corona cage

For further study of the discharge mechanism and audible noise's characteristics of positive, negative and bipolar UHVDC test line, the audible noise's spectrum for 6×720 mm2 wires were tested and analyzed based on the corona cage in the UHV-DC test base of State Grid Corporation of China. Using the mid-net detachable corona cage, the audible noise of positive, negative and bipolar lines in corona cage were tested, and the noise's spectral characteristics of positive, negative line and that near the bipolar pole, and their relationship with voltage were reached, and the comparative analysis of their results were conducted. The paper also analyzed the stability of corona audible noise's A weighed sound level and its 8 kHz components in different surface field strength when the background noise was also considered. Finally, the 8 kHz component method which was proposed before being used to analyze the noise's characteristics of positive, negative pole and the noise near dipole line in different surface field strength, and the 8 kHz component can be used to calculate the noises of positive and dipole line. © 2014 Chin. Soc. for Elec. Eng.