Development of fiber-optic current sensing technology for electric power systems

This paper describes development and applications of a fiber-optic electric current sensor with stable properties and compact, simple, and flexible structure. The special characteristics of the sensor were achieved with use of special low birefringent fiber as the Faraday-effect sensing element, and were also achieved with creation of a sensing scheme which matches with the properties of the fiber. Making use of the excellent features of the sensing technology, various current monitoring devices and systems were developed and applied practically for control and maintenance in electric power facility. In this paper, examples of field tests and practical applications of such systems are introduced, including fault section/point location systems for power transmission cable lines.