Development of Fiber-Optic Voltage Sensors and Magnetic-Field Sensors

The principle, temperature characteristics, and frequency characteristics of fiber-optic voltage sensors and magnetic field sensors are reported, along with the results of an aging test on these sensors. The fiber-optic voltage sensor utilizes the "Pockels" effect of Bi12SiO20 single crystal and the fiber-optic magnetic-field sensor utilizes the "Faraday" effect of ZnSe polycrystal and Bi12SiO20 single crystal. The basic performance of these sensors has been investigated from the perspective of their use as parts in electrical apparatuses. In addition, in this paper some practical applications in electrical substations and transmission lines are presented. These include a fault section detecting system for gas insulated transmission line (GIL), an optical voltage transformer and optical current transformer which are embedded in gas insulated switchgear (GIS), and a surge voltage receiving system.