Direct measurement just under surface discharge on PMMA by Pockels electric field sensors

Abstract

Surface discharge is one of the main phenomenons in electric apparatus's fault, but has not yet been cleared. The measurement of electric fields in or near a streamer while surface discharge creeps is greatly helpful for it. There is optical measurement technique for electric fields by using Pockels crystal, and optical waveguide technique has been successfully introduced to miniaturize the sensors. The measurement of electric fields just under surface discharge is tried with the optical waveguide Pockels sensor installed on a PMMA plate and output signals according to its advance are obtained.