Analytical investigation on OPGW strands melting due to DC arc discharge simulating lightning strike

Some metal strands of OPGW (composite fiber-optic ground wire) are sometimes melted and broken by lightning strikes. DC arc tests simulating lightning strikes have thus been performed to obtain their melting and breaking characteristics. In this paper, calculations regarding these melting characteristics are performed considering the transferred heat and its area from the arc to the strands. The melting characteristics of strands are calculated with an arc current of 0.1 - 100 kA, considering the current prescribed in the IEC standard and the measured actual lightning current. The calculation results of the strand melting duration depending on the arc current show a good agreement with the experimental values obtained in DC arc tests.