Lightning induced voltage due to inclined lightning channel

Lightning is an unpredictable natural phenomenon which manifests itself in a few different ways. The cloud-to-ground type with negative downward lightning is the most common type that contributes to some 90 % of the occurrences of lightning strikes. There is a negative discharge more often than a positive discharge to the ground and the negative discharge is known to give a higher value for the peak current during the first stroke as compared to the subsequent lightning strokes. This characteristic contributes to the damage to electrical power apparatus and the danger to human life. Lightning may also cause failure in a power system network such as medium and low voltage distribution lines which have a lower critical flashover (CFO) than the transmission system. For instance in Malaysia a statistical analysis of the performance of the electricity supply shows that at least 51 % of interruptions are caused by voltage transients.