Effects of the intensity of precipitation and transverse wind on the corona-induced vibration of HV conductors

The effects of rainfall intensity, electric field strengths, alternating and both polarities of direct voltage, and the velocity of an ACSR conductor were studied. The results obtained showed that the amplitude of the vibration was linearly proportional to the intensity of precipitation up to 24 mm/h. When the intensity of precipitation was higher than 24 mm/h, the amplitude of the vibration remained constant. At a constant intensity of precipitation and a steady vibration, the amplitude of the vibration was generally highest with negative DC fields and lowest with AC fields. The effects of transverse wind velocity upon the vibration were studied under a constant precipitation rate using a wind tunnel generating winds with velocities up to 50 km/h. As a result, two critical wind velocities, V/sub C1/ and V/sub C2/, were established. V/sub C1/ represented the point at which the corona-induced vibration began to decrease and V/sub C2/ the point at which the vibration stopped. Under both alternating and direct voltages, V/sub C1/ decreased with an increase in the applied field, while V/sub C2/ remained at about 25 km/h. Photographs of water droplets hanging from the conductor were taken in order to document the effect of wind velocity on the shape of the hanging drops.<
>