Multiple wall structure for flexible cable using tubular and spiral corrugations
AssigneeElectric Power Research Institute, Inc.
InventorsPhilip C. Netzel, Edward M. Spencer
Life of this patent
Estimating the term…
Abstract
The central conductor of a gas-insulated flexible cable consists of separate concentric tubes which are alternately spirally corrugated and annularly corrugated so that the corrugations will not nest relative to one another and are axially movable relative to one another.
Claims12
A flexible gas-insulated electrical cable;
- said gas-insulated cable comprising an elongated flexible tubular outer electrically conductive housing;
- an elongated flexible central electrical conductor extending coextensively with and insulated from said outer housing;
- a plurality of insulator support devices spaced along the axis of said cable and connected to and supporting said central conductor along the axis of said flexible cable and a dielectric gas under positive pressure filling the interior of said tubular outer housing;
- said central conductor comprising a plurality of concentric elongated flexible hollow electrically conductive tubes of approximately equal wall thickness in close radial relationship to one another;
- said tubes forming the major current carrying bodies of said cable;
- said plurality of tubes being independently slidable relative to one another, whereby said plurality of concentric elongated tubes are flexible independently of one another.
A flexible electrical conductor comprising a plurality of concentric parallel connected elongated flexible hollow electrically conductive tubes in close radial relationship to one another and of approximately equal wall thickness;
- said plurality of tubes being independently slidable relative to one another, whereby said plurality of concentric elongated tubes are flexible independently of one another;
- the annular space between said tubes being gas filled.
In a high voltage transmission cable of a type including an elongated inner current conductor, a composite inner tubular current conductor comprising:
- a first corrugated tubular conductor;
- and
- a second corrugated tubular conductor positioned concentrically about said first tubular conductor, said second tubular conductor having corrugations that differ from those of said first tubular conductor in wave pitch, shape, depth or longitudinal separation, so as to permit longitudinal sliding movement between a plurality of engagements of various corrugation protrusions of one of said first and second tubular conductors with the immediately adjacent surface areas of the other of said first and second tubular conductors;
- whereby such permissible longitudinal sliding avoids internal longitudinal entanglements and anchoring between said tubular conductors upon differential longitudinal expansion of said first tubular conductor with respect to said second tubular conductor as a result of differences in high temperature operational conditions experienced by said tubular conductors, radial separation is maintained between said first and second tubular conductors as a result of said plurality of engagements, and high flexibility of the composite conductor is achieved notwithstanding a large aggregate current conducting cross-sectional area of said composite conductor.
Dependencies are inferred from the claim text.