Lightning and Transmission Lines Design
Employing adequate protection can minimize lightning-induced overvoltage on transmission lines.
The normal practice of protection against overvoltages by power transmission companies is to employ static-wire shielding and arresters to divert these voltage surges to ground.
Even with the protection of shielding, a low percentage of strokes may penetrate the static-wire shielding.
In addition, induced surges will occur on the line due to the presence of lightning in the area.
When this happens,
arresters (if used) will divert this surge energy to ground.
If no arresters are used,
or they are too far from the strike area,
backflashover of the insulators will occur