Conductor Surface Conditions Effects on Audible Noise Spectrum Characteristics of Positive Corona Discharge

Conductor surface conditions of high voltage overhead transmission lines have a large influence on corona characteristics. Both audible noise and corona current is highly depended on the corona discharge characteristics. However, relatively few investigations have previously been made on conductor surface conditions effects on audible noise spectrum characteristics. In the present work, the artificial pollution experiments were carried out to simulate the various surface conditions. At the same time, the audible noise spectra and the corona current of the polluted conductor are recorded. From the analysis of the experiment results, it was found that the audible noise spectra level (>1 kHz) and corona current increased obviously as the relative permittivity grew and the amount of pollution increased. Furthermore, from the results of the long-term statistical measurement about A-weighted equivalent continuous sound level (LAeq) of the polluted conductor, the close correlation between the surface potential gradient and the audible noise spectra were obtained.