Novel fiber-optics-based current sensor for power system protection

Fiber-optics-based magnetic field sensors have investigated for current measurement. These sensors have potential in power system protection. Particularly, they can easily be connected to form a sensing network that will coordinate the response of power protective devices and assist power system restoration. Basic components of these sensors are a passive rugged fiber-Bragg-grating and a fast and compact magnetostrictive transducers that can translate magnetic field into optical signal. In additional to easy integration into an optical sensing network these sensors can be compensated for temperature drift. A broadband light source at a central location (e.g. a substation) scans the change in optical power reflection at a unique frequency band that corresponds to the surge in magnetic field associated with an increased fault current at a certain sensor location. In this paper, we report our recent alternating current and direct current measurements with these sensors.