Development of electro-optic polymers for high-voltage instrument transformers

Abstract

This paper describes some poled electrooptic bulk polymers (EOP) of the guest/host type having a cured epoxy resin as the host. The electrooptic polymers of typical dimensions 13 X 13 X 3 mm are characterized with respect to application as Pockels materials in an optical high voltage sensor. The electrooptic coefficients obtained here are of the same order of magnitude as those which are required for high voltage applications. An optical sensor based on disperse red 1 dye and an epoxy polymer is developed. It is able to measure voltages up to 10 kV AC. It is shown that bulk EOP can be produced with relatively large physical dimensions comparable to commercially available Pockels crystals. A technique is described which compensates for the inevitable intrinsic birefringence built into most bulk polymers. The epoxy based EOP shows high orientational stability, even when compared with a polysulfone based EOP having a higher glass transition temperature