Development of a distribution line state monitoring and controlling system by combination of remote control switches with new optical current sensors

As the advanced information age continues to develop, customers´ needs for a stable electricity supply and the efficient consumption of electricity are continuing to expand. To enhance power supply reliability, The Kansai Electric Power Co. has been extending its automatic power distribution operating system to its entire service area (covering about 11 million users) since 1989. To reduce service interruption time over long distance distribution grids in rural service areas, the authors have developed a “distribution line state monitoring and controlling system” that minimizes failure-affected service areas by detecting failures such as grounding, short-circuits, and open phase failure. This system employs a unique form of cost reduction, with no voltage sensors incorporated. Optical sensor elements have also been developed to maintain high reliability of power systems that are exposed to harsh environments, such as on the top of outdoor utility poles under temperature extremes