Preliminary evaluation of flat glass backed mica paper tape for high voltage coil groundwall insulation using vacuum-pressure-impregnation

Abstract

Of interest, is to find a glass backed mica paper tape with improved dielectric properties than commercially available tapes [1]. This paper is a second on the subject and presents the results of a preliminary evaluation of flat glass backed mica paper tape. These tapes were evaluated for possible use for high voltage coil groundwall insulation using vacuum-pressure-impregnation (VPI) with epoxy resins. Flat Glass Mica Paper tape was used to insulate aluminum test bars and impregnated using a VPI process using epoxy resin. The impregnating resin and process is used in the fabrication and processing of high voltage stator coils usually insulated with glass backed mica paper tape. An evaluation of the insulated test bars was done and the results are compared to other commercially available glass backed mica paper taped test bars; processed and evaluated under identical conditions. The flat glass mica paper tape was used to make up insulated full size stator coils which in turn were subject to electrical, chemical, and mechanical testing. This paper reviews the results of the evaluation of the flat glass mica paper tape; showing good dielectric properties that make it suitable for use in high voltage coil insulation.