Analysis of light emission and Schlieren from short gap high voltage streamers representing lightning impulses

Abstract

Light emissions and Schlieren structures were simultaneously observed from streamers produced by tens of kilovolts 1.2/50 μs impulses, representing the high voltage component of lightning, applied across a 4 cm air gap between a variety of electrode geometries and a ground plane in an unconfined environment. The results demonstrated that the light emissions and Schlieren structures coincide along the same streamer filaments but on different timescales; the light existing only during the microsecond timeframe impulse whereas the Schlieren continued to develop into the millisecond timeframe, moving towards the centre of the air gap whilst diffusing into the surrounding air within 100 ms. If an electrical breakdown did occur, the Schlieren structures outside the arc remained visible. Streamer formation theory for high voltage impulses is subsequently refined to include the observed Schlieren mechanism.

Point cloud registration of arrester based on scale-invariant points feature histogram

“…The lightning arrester is a kind of lightning protection device, whose function is protecting power facilities from lightning strikes. Arrester is widely used in overhead distribution lines 1 , 2 . However, the arrester will conduct electricity under non-lightning conditions when the creepage distance (the shortest distance along the surface of a solid insulating material between two conductive parts), umbrella distance (the shortest distance between the edges of two skirt structures) and other parameters are not standard.…”