Effect of insulating coating on lightning flashover characteristics of electric power line with insulated covered conductor

Both bare conductors and insulated covered conductors are used in overhead distribution line systems. The difference in those conductors will affect striking distances of the conductors to lightning, lightning occurrence probabilities to the conductors and shielding effects of grounding objects on direct lightning. In this research the lightning flashover characteristics and the lightning occurrence probabilities on overhead distribution lines have been studied experimentally at a reduced scale-model. The voltage applied to electrodes in the experiment has a rise time of 1.2 microseconds and a peak to half value decay time of 50 microseconds. This paper presents the experimental data, the lightning flashover characteristics and lightning occurrence probabilities of those conductors.