FAULT DIRECTION JUDGEMENT DEVICE FOR TRANSMISSION LINE

摘要

PURPOSE: To discriminate a fault direction with a sensor laid at one position, regardless of a condition for a line system, by positioning the sensor so as to face an aerial transmission line in non-contact state in the vicinity of the connection of the line to an underground transmission line, and detecting voltage between a plate type electrode isolated from a steel tower and the ground. ;CONSTITUTION: A current sensor 21 uses ZCT and is provided at a position where three phases of underground transmission lines 30 are gathered. A voltage sensor 13 is provided for each phase of aerial transmission lines 10, and faces to each of the three phases thereof in non-contact state. Also, the voltage of a plate type electrode 11 isolated from ground potential with an insulator 12 or the like is detected with a photovoltaic sensor 13 utilizing a Pockels effect. The signals so detected are inputted to and processed with a discrimination device 30. Also, this device 30 is driven on power from a solar battery 31. Voltage is separately detected for each phase in that way and, therefore, a voltage signal processing section involves a three-phase composing process for finding zero-phase current. In a phase comparison section, the phases of the zero-phase current and zero-phase voltage are compared, thereby enabling a fault direction to be discriminated at the place concerned.;COPYRIGHT: (C)1995,JPO