Switching surge test for air insulation design of 765 kV double circuit transmission line

Test results of air insulation design of a Korea Electric Power Corporation 765 kV double circuit transmission line are presented. To determine the air clearance between 6-conductors and the tower body, upper crossarm and lower crossarm, respectively, suspension, tension and V insulator strings were tested in a full scale mockup by using a 4 MV outdoor impulse generator.