Development of an optical current transducer with a bulk type Faraday sensor for metering

An optical current transducer (OCT) with a bulk type Faraday sensor demonstrated 0.3 % class accuracy for metering. The Faraday sensor had Bi12Si020 (BSO) single crystals with right and left optical rotatory power to cancel out temperature dependency. A prototype 161 kV OCT installed in a TVA substation verified 0.3 % class performance. The OCT had the Faraday sensor, a gapped magnetic iron core, a 1.6 m optical insulator, and an optical interface.