The corona effect is a phenomenon of partial electrical discharge that occurs when the electric field strength at the surface of a conductor exceeds the dielectric strength of the surrounding air. This ionization of the air produces a faint bluish glow, hissing sound, power loss, and radio interference.

To mitigate the corona effect, we implement several design strategies:

• Larger Conductor Diameter: A larger diameter conductor reduces the electric field gradient at its surface, thus minimizing the likelihood of corona discharge.

• Bundled Conductors: For very high-voltage lines (typically 220 kV and above), multiple smaller conductors are used in a bundle, which effectively increases the overall equivalent diameter of the conductor, significantly reducing the electric field and corona losses.

• Smooth Surface: Conductor defects, scratches, or moisture on the surface can increase the local electric field. Using conductors with a smooth, clean surface helps in reducing this effect.