Influence of Internal Microscopic Interface on Electric Breakdown Characteristics of FRP

Abstract

Recently, the application of fiber reinforced plastics (FRP) for high-voltage use has rapidly increased. In particular, unidirectionally pultruded FRP rods have become indispensable for composite insulators or handling rods of circuit breakers and so on. Therefore, they are always required of the stable and excellent breakdown properties. As they are comprised of bundles of glass fibers and epoxy resin, and have a lot of internal microscopic interfaces which affect the breakdown properties.In this paper, two kinds of unidirectionally pultruded FRP rods with voids and no void were prepared, and their electric breakdown characteristics were studied about the differences of the kind of the applied voltage, the interface angles (angle between the direction of glass fibers and that of rod electrode), and about the influence of the moisture ingression to FRP, medium existing around the rod electrode. Furthermore, the photographic observation of breakdown path and other places of FRP by means of Scanning Electron Microscope device and the electric field analysis by means of the computer software were conducted.