Optical investigation methods for determining the impact of rain drops on HVDC corona

• An optical investigation method for corona on wet overhead-lines is introduced.
• The method allows correlating optical and electrical properties (e.g. corona losses).
• Optical properties include: drop number, position, size, and location of discharges.
• The method is used to automatically detect these properties on a 1.5 m line section.
• Applying the method resulted in new findings on corona during and after a rain shower.

Corona behavior of HVDC overhead lines plays a significant role when dimensioning transmission lines. Rain constitutes an important study case since corona effects (e.g. losses, discharge amplitudes) are considerably affected. In this paper, imaging methods are introduced to investigate the impact of rain on corona behavior. Geometrical properties of rain drops on a stranded conductor were extracted. UV-images were used to precisely locate discharges. The methods' capabilities are demonstrated using data from an indoor test line during a simulated rain shower. Optical and electrical data were correlated. These methods aim to support the development of surfaces with favorable corona properties.

Figure optionsDownload as PowerPoint slide