SECTIONAL DISCRIMINATION FAULT LOCATOR FOR COMPRESSED GAS INSULATED TRANSMISSION LINE

摘要

PURPOSE:To simplify the equipment by mounting a magnetic field detection sensor across the predetermined compressed gas insulated transmission line section and inputting an output difference thereof into a differential circuit to discriminate the section of a ground-fault accident. CONSTITUTION:It is assumed to monitor the L section between points A and B of a compressed gas insulated transmission line GIL. A magnetic field sensor 2 utilizing Faraday effect comprising BSO is provided at the point A while a magnetic field sensor 3 utilizing Faraday effect comprising BSO at the point B. Light outputs corresponding to currents from both the magnetic field sensors 2 and 3 are transmitted through a 2-core optical fiber cable 4 and inputted into photoelectric conversion units 5 respectively. The electric outputs thus converted are inputted into a differential circuit 6 and a differential current pair signal is outputted by comparing both the inputs to discriminate the section of a ground- fault accident. This can miniaturize the current detecting section to simplify the equipment.