The Effect of Surface Treatment on the Audible Noise of a High Voltage Conductor

The conductors of high-voltage electrical transmission networks emit strong noise in wet weather. It is caused by the formation of corona radiation on their surface. The high electrical field gradient at the surface deforms the water droplets formed on the conductors’ and the droplets amplify the corona radiation. The corona radiation not only indicates noise, but it is a loss too. The reduction of the corona radiation also reduces the loss of the transmission. Reducing the intensity of corona radiation can be achieved by improving the wettability of the surface to hinder the formation of large droplets. One way to do this is to blast the surface. However, in addition to the study of wettability, an important question is how the conductor behaves during operation. It is possible to examine in laboratory conditions with the application of high voltage and artificial rainfall. The experience gained from this type of experiment is presented in the article.