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 Bi//1//2 SiO//2//0 single crystal, and the fiber-optic magnetic-field sensor utilizes the Faraday effect of ZnSe polycrystal and Bi//1//2 SiO//2//0 single crystal. The basic performance of these sensors has been investigated from the perspective of their use as components in electrical apparatuses. Some practical applications in electrical substations and transmission lines are also presented. These include a fault-section detecting system for gas-insulated transmission line, an optical voltage transformer and optical current transformer which are embedded in gas-insulated switchgear, and a surge-voltage receiving system.