Impact of surface conditions on corona-generated audible noise for long-term operating conductors in UHVDC transmission lines

摘要

Conductor surface conditions have a great influence on corona characteristics. Corona-generated audible noise is largely depended on the intensity of the corona discharge. It was found that the coarse and uneven level of the surfaces of the strands increase in the order of new, 1-yrs, 3-yrs and 5-yrs strand. The intensity of corona discharge for the aged conductors is much stronger than that for the new ones. The audible noise spectral components (>0.25kHz) and Aweighted equivalent continuous sound level (LAeq) increase obviously as the increase of the service time. The close correlation between the surface potential gradient and the audible noise spectra is obtained.