GIS monitoring sensors

As the electric power system is expanding, more and more equipment is being installed in Japan. Moreover, unattended substations (s/s) are increasing and more s/s are installed in places which are a long distance from cities. If any equipment fault occurs, it would cause severe disturbances to supply to the consumer which needed a long time to restore. Thus, predictive maintenance equipment is being requested to prevent equipment failure. The authors carried out investigations and the development of a partial discharge (PD) sensor which can predict the earth faults of gas insulated switchgear (GIS) in the early partial discharge stage.