GROUND FAULT LOCATING METHOD FOR HIGH-VOLTAGE POWER DISTRIBUTION LINE

摘要

PURPOSE:To accurately locate a ground fault while eliminating a failure in conduction due to a film by applying a voltage which breaks the oxide film of the contact surface of a switch between high voltage power distribution lines for applying an AC voltage for locating to the ground. CONSTITUTION:While an (a) contact point 6 is opened and a (b) contact point 7 is closed, the AC voltage Eg for locating is applied between output terminals R and T of a current transformation part 3 and the ground and no voltage is developed between the terminals R and T. When the contact point 6 is closed and the contact 7 is opened, the voltage of an oxide film breaking voltage source 2 is applied between input terminals RV, TV of the current transformation part 3 and the loop of circuit elements LR, CTR, CTXR, CTXT, CTT, and LT is closed, so that the film breaking voltage reduced by the CTR and CTT is applied between the terminals R and T. The voltage between the terminals R and T is set to AC 100V. The oxide film is broken completely in two sections at 100V and continuity is held at 2V thereafter. In this constitution, the oxide film is broken in several seconds only by switch operation and the ground fault is located speedily and accurately.