Investigation on lightning attachment manner by use of an experimental distribution line and a tree

Abstract

The authors have examined over a period the basic characteristics 01 discharge when an open wire fitted as an overhead ground wire is located near a tree. to clarify the attachment manner in which direct lightning hits power distribution lines which are in close proximity to trees. Previously, a focus was made on how lightning attachment emerges to the open wire or the tree. In this latest experiment, made at a testing yard using an experimental distribution line and a tall tree, a lightning impulse waveiorm and a switching impulse waveiorm were applied individually to a rod electrode. The different manners of attachment of sparkover to the distribution line and the tree were observed. along with manners of prebreakdown phenomena. This result coincided with the lightning attachment status previously achieved. This experiment revealed that the discharge Characteristics shown in the previous study are valid.

Attachment of Natural Lightning Flashes to Trees: Preliminary Statistical Characteristics

“…Although a higher tree should have a larger electric field at the tip, the lower resistance of a decaying stump can cause it to be the favored path. A related effect may be that observed in controlled environments by [28], in which artificial lightning currents tend to avoid striking high trees when a better grounding is available lower down. We suggest that to determine the path of the current, several factors need to be considered separately: the field intensification due to a sharp peak, the conductivity of the tree, the location of the best electrical ground, and the best path down to the electrical ground.…”

Modelling and evaluation of the lightning arc between a power line and a nearby tree

“…But not all these strokes terminate directly on the ground. Distribution lines and equipment around the forests are protected naturally from a direct hit by lightning strokes [3][4][5][6]. Distribution lines and equipment around the forests are protected naturally from a direct hit by lightning strokes [3][4][5][6].…”

“…Lightning terminates on trees in most areas where the power networks traverse the forest areas, such as in Finland (Figure 1). Distribution lines and equipment around the forests are protected naturally from a direct hit by lightning strokes [3][4][5][6]. As shown in Figure 1, if the tree intercepts the lightning stroke, an arc may ignite caused by the existence of mutual coupling between the tree and power line/equipment; another factor that may cause the arc ignition is the conductive properties of rainstorm during the lightning incidence.…”