The Correlation between Audible Noise and Corona Discharge on an Overhead Line Conductor under Positive DC Voltage

Audible noise is generated in HVAC and HVDC transmission systems as a result of elevated electric fields at the conductor surface. This can be enhanced by pollution, damage and raindrops. Within this paper, a superhydrophobic coating was applied to a conductor to examine whether it can reduce the audible noise under a positive DC voltage. Partial discharge was measured to explore the correlation between corona discharge behavior and audible noise. Unlike the noise reduction with using superhydrophobic coating on the HVAC conductor, the coated conductor shows a higher audible noise level than the uncoated conductor under positive DC voltage. The total partial discharge magnitude also has trend similar to the audible noise performance. It is shown that the A-weighted sound pressure level is correlated to the total partial discharge magnitude.