Estimation of Time Variation of Current Density in a 50 kA Lightning Impulse Arc using High Speed Cameras

This paper describes a 50 kA lightning impulse arc test to optical ground wires (OPGWs), focusing on the external appearance of the lightning impulse arc. Two types of high speed cameras were employed to observe time resolved pictures of the arc. We estimated the diameter of the arc from its shape in the observed pictures. We subsequently obtained the time variation of the current density in the arc. The estimated arc diameter was in good agreement with the values obtained from other literature, thus, the current density obtained in this study can be considered valid. We calculated an estimate of the distribution of energy input to the OPGW, as a result of electron transport.