Corona-resistant insulation, electrical conductors covered therewith and dynamoelectric machines and transformers incorporating components of such insulated conductors
AssigneeGeneral Electric Company
InventorsDon R. Johnston, Mark Markovitz
Life of this patent
Estimating the term…
Abstract
Resinous compositions used as electric insulation have unique corona-resistance increased from 10- to 100-fold or more by the addition of organoaluminate, organosilicate or fine alumina or silica of critical particle size, and dynamoelectric machines and transformers incorporating coils made of wire strands coated with these novel compositions consequently have substantially increased service lives.
Claims17
A method of providing an electric conductor wire with corona resistant insulation comprising covering at least a portion of the said wire wih a composition consisting essentially of polymeric material containing an amount of an additive providing corona resistance at least 10 fold greater than that of the polymeric material itself, said additive being selected from the group consisting of organoaluminate compounds, organosilicate compounds, silica of particle size from approximately 0.005 micron to approximately 00.05 micron, and alumina of particle size from approximately 0.005 micron to approximately 0.05 micron said polymeric material being a resin selected from the group consisting of polyimide, polyamide, polyester, and glycidyl ether of polyphenol epoxy resin.
A transformer component comprising a coil of a strand of copper wire insulated with polyester wire enamel containing between about 5% and 40% of an additve selected from the group consisting of alumina and silica of particle size between about 0.005 and 0.05 micron, said wire enamel having corona resistance 100 times greater than the same wire enamel containing none of the said additive.
A dynamoelectric machine comprising a rotor, and a stator including a plurality of coils each of which comprises a plurality of conductor strands coated with an electric insulating composition consisting essentially of polymeric material containing an additve selected from the group consisting of alumina and silcia of particle size from approximately 0.005 to 0.05 micron in amount effective to increase the corona resistance of the said polymeric material by at least 10 fold, said polymeric material being selected from the group consisting of polyimide, polyamide, polyester, and glycidyl ether of polyphenol epoxy resin.
A dynamoelectric machine component having unique corona resistance which comprises a coil formed of a strand of electrically conductive wire insulated with a composition consisting essentially of polymeric material containing an additive selected from the group consisting of alumina and silica of particle size from approximately 0.005 to 0.05 micron in amount effective to increase the corona resistance of the said polymeric material by at least 10 fold, said polymeric material being a resin selected from the group consisting of polyimide, polyamide, polyester, and glycidyl ether of polyphenol epoxy resin.
An electrical conductor coverd with an insulating coating consisting of a polyester wire enamel and alumina filler, said alumina filler being of particle size from about 0.005 to 0.05 micron and in amount from about 5% to 40% by weight of the insulating coating.
Dependencies are inferred from the claim text.