Medium-voltage or high-voltage electrical device having low-thickness hybrid insulation
AssigneeGeneral Electric Technology GmbH
InventorsDavid Gautschi, Robert Luescher, Yannick Kieffel, François Biquez
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Abstract
A medium-voltage or high-voltage electrical device comprising a sealed enclosure in which are located electrical components covered with a solid dielectric layer and a gaseous medium ensuring electrical insulation and/or extinguishing electrical arcs, the gaseous medium comprising heptafluoroisobutyronitrile and a dilution gas, the thickness of the solid dielectric layer being less than 1 mm and being produced from a material comprising a polyepoxide or polyurethane resin optionally containing a filler or aluminum oxide.
Claims12
A Medium- or high-voltage equipment comprising:
- a leak tight enclosure including a gaseous medium, the gaseous medium comprising at least heptafluoroisobutyronitrile in a mixture with a dilution gas;
- and
- electrical components located in the leak tight enclosure, at least one surface of the electrical components having a sand cast surface finish, the at least one surface of the electrical components including a solid dielectric layer to reduce a surface roughness of the sand cast surface finish of the at least one surface,
- wherein a thickness of the solid dielectric layer is less than 1 mm, and
- wherein a utilization factor of an electric field generated by the electrical components is greater than or equal to 0.2, the utilization factor being a ratio of a mean electric field divided by a maximum electric field, and
- wherein the solid dielectric layer is made of a material comprising a polyepoxide resin, a polyurethane resin, or aluminum oxide.
A method for extinguishing an electrical arc in medium- or high-voltage equipment, the method comprising:
- providing a gaseous medium to a medium- or high-voltage equipment including a solid dielectric layer, the gaseous medium comprising a mixture including at least a dilution gas and heptafluoroisobutyronitrile,
- wherein the medium- or high-voltage equipment includes electrical components located in a leak tight enclosure, at least one surface of the electrical components having a sand cast surface finish, the at least one surface of the electrical components including a solid dielectric layer to reduce a surface roughness of the sand cast surface finish of the at least one surface,
- wherein a thickness of the solid dielectric layer is less than 1 mm, and
- wherein a utilization factor of an electric field generated by the electrical components is greater than or equal to 0.2, the utilization factor being a ratio of a mean electric field divided by a maximum electric field.
Dependencies are inferred from the claim text.