Abstract:Lightning trip-out is one of the major problems in operation and maintenance of 10 kV distribution lines. Based on the Agrawal model, a lightning-induced overvoltage module of 10 kV three-phase conductor is established in ATP/EMTP considering the conductor coupling effect. The trip-out rate of induced overvoltage is studied when lightning stroke is 50 m far away from the line, and the results show that the minimum lightning current amplitude required for tripping increases linearly with the increase of 50% flashover voltage of insulator, and insulation flashover occurs more easily at branch. The arrangement of lightning arrester is also studied, and the results show that under the same installation density, the effect of scattered installation of three-phase arrester is better than the centralized installation, and for branch tower, it is better to install arrester on the nearest main line or branch line tower.