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AssigneePirelli Cavi e Sistemi S.p.A.
InventorsClaudio Bosisio, Gianmario Lanfranconi, Gianni Miramonti, Franco Peruzzotti
Estimating the term…
Mass-impregnated electrical cable, particularly for carrying high voltage direct current, having an insulation in which, around the insulating layer impregnated with an insulating fluid, a containing layer is provided broadly includes at least one winding of a tape of a semiconducting elastomeric material, which exerts an effective action of containing the insulating fluid, while preventing formation of micro-cavities within the impregnated insulating layer. The material constituting the tape has high physical-chemical resistance to the degrading action of the components of the insulating fluid, both in the cold state and, in particular, at the operating temperature of the cable.
Cable, particularly for carrying high voltage direct current, comprising an electrical conductor, at least one semiconducting layer, a stratified insulating layer impregnated with an insulating fluid, and a metal sheath disposed on the outside of said insulating layer, characterized in that between said insulating layer and said metal sheath a layer for containing said insulating fluid is provided, comprising at least one winding of a tape made from a semiconducting elastomeric material having physical-chemical resistance with respect to said insulating fluid, said elastomeric material being such that a test specimen of said elastomeric material, kept under traction with an imposed elongation of 50% and immersed in said insulating fluid for 360 days at 85° C., has a permanent elongation of less than 35%.
In a mass-impregnated electrical cable comprising a stratified insulating layer impregnated with an insulating fluid, a method for preventing formation of micro-cavities within said insulating layer, said method comprising winding a tape of an elastomeric material around said layer so as to form a containing layer for said insulating fluid around said insulating layer, said elastomeric material has physical-chemical resistance with respect to said insulating fluid such that a test specimen of said elastomeric material, kept under traction with an imposed elongation of 50% and immersed in said insulating fluid for 360 days at 85° C., has a permanent elongation of less than 35%.
Dependencies are inferred from the claim text.