OPTICAL VOLTAGE TRANSDUCERS

Abstract

The paper presents basic operating principles of optical transducers for the measurement of high voltage. It was observed by Pockels that the change in refractive indexes in certain crystals is proportional to the applied electric fi eld. The main parts of the sensor based on Pockels effect are: polarizer, Pockels crystal and analyzer. These are passive elements to and from which the light is taken by means of optical fibers from an electronic device at the earth potential. The polarized light that vibrates in two mutually perpendicular planes passes through the crystal at different speeds that change under the infl uence of the electric fi eld, which is detected by an electronic circuit. The longitudinal and transverse effect are distinguished with respect to the applied electrical field.