摘要
Overhead line conductors can generate audible noise across a wide frequency spectrum as a result of elevated electric fields at the conductor surface.Such fields are enhanced by the presence of surface defects,insects,water drops and pollution.Within this paper,the impact of a superhydrophobic coating on the audible noise produced by an overhead line conductor is examined.Noise levels from a conductor coated with a superhydrophobic coating were compared to those from a bare conductor in a semi-anechoic chamber.The conductors were energised at voltages to provide surface electric fields ranging from 6 kV/cm to 21 kV/cm(rms).With a continuous water spray system depositing droplets on the conductor surface,the frequency domain sound pressure level,overall sound pressure levels and corona discharge magnitude were measured.It is demonstrated that the use of a superhydrophobic coating reduced audible noise levels and corona discharge magnitude,especially at electric fields above 14 kV/cm.The image analysis suggests that the water drop size distribution and the position of surface droplets on the conductor circumference play an important role in the magnitude of audible noise.