Calculation of OPGW Strands Melting due to DC Arc Discharge Simulating High-Energy Lightning Strike

Abstract

Metal strands of OPGWs (composite fiber-optic ground wires) installed in overhead power transmission lines are sometimes melted and broken when struck by high-energy lightning. This paper presents the calculation results regarding OPGW strands melting behavior when struck by DC arcs simulating high-energy lightning. The calculations revealed that the melted volume of the strand was 26% of the strand volume before the arc test, i.e. the rate of the non-melted volume of the strand was 74%. On the other hand, the residual tensile strength of the melted strand was 69% of the other non-melted strands after DC arc test. These results suggest there is a strong correlation between the calculated non-melted volume of the strand and the measured residual tensile strength of the melted strand.