Patent US3930113A successfully refreshed from Google Patents.
US3930113A
Expired / Lapsed
US
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High voltage overhead transmission line conductor with reduced wet weather corona noise and corona losses
Assignee: Massachusetts Institute of Technology
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Filing: 1974-06-10
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Granted: 1975-12-30
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Expires: 1994-06-10
Abstract
Abstract An electrical conductor having the ability to absorb and store water appearing on the surface and to remove the stored water by transporting it to an expulsion site. This is achieved in one embodiment by supplying a central conductor with a porous, absorbent and electrically conducting outer layer. Similar results obtain when the strands of a multi-strand conductor are provided with azimuthal threads or grooves of a certain fineness and an additional electrochemical or chemical treatment of the surface for improved wettability.
Inventors
- 👤 Inge Johansen
- 👤 David W Tong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:42
CPC Classifications
H; H01; H01B; H01B5/00; H01B5/08; H01B5/10
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
56 words
An electrical conductor for use in very high voltage or ultra-high voltage systems, that comprises: a plurality of conductive strands bound together in a plurality of layers, the outer surface of the conductor being moisture absorbent so that moisture is drawn by capillary action from said outer surface and toward the longitudinal axis of the conductor.
Claim 2
Dependent Claim
56 words
An electrical conductor for use in very high voltage or ultra-high voltage systems, that comprises: a plurality of conductive strands bound together in a plurality of layers, the outer surface of the conductor being moisture absorbent so that moisture is drawn by capillary action from said outer surface and toward the longitudinal axis of the conductor.
Claim 3
Dependent Claim
52 words
An electrical conductor as claimed in claim 1 in which each said strand contains at the outer surface thereof a plurality of grooves having widths small enough so that capillary action occurs at said outer surface, thereby rendering said outer surface water absorbent, and the dry corona threshold is not greatly affected.
Claim 4
Dependent Claim
36 words
An electrical conductor is claimed in claim 2 in which the grooves are disposed at an angle to the axis of the strand and in which the surface of the strand is treated to enhance wettability.
Claim 5
Dependent Claim
43 words
An electrical conductor as claimed in claim 3 having spout means to expel moisture from the conductor and having means to transport moisture longitudinally along the conductor from the region at which it enters the interior of the conductor to the expulsion site.
Claim 6
Dependent Claim
87 words
An electrical conductor as claimed in claim 4 in which the means to transport moisture comprises the substantially open channels that appear in the interior of the conductor between the strands thereof and in which the spout means comprises wick means in intimate contact with the conductor at the explusion site to remove the moisture from the interior of the conductor, the wick being pendent from the conductor so that the moisture is drawn by gravity and falls as drops from the lower end of the wick.
Claim 7
Dependent Claim
58 words
An electrical conductor as claimed in claim 4 in which the spout means comprises a fairly large conductive shell that surrounds and electrically shields the region of physical contact between the wick and the conductor at the expulsion site, an aperture being provided at the lower part of the shell to permit the water drops to pass through.
Claim 8
Dependent Claim
58 words
An electrical conductor as claimed in claim 6 in which the wick is a glass fiber wick wound tightly around the conductor at the explusion site and in intimate contact with the grooves at the outer surface of the strands to draw moisture from the grooves at the outer surface and hence from the interior of the conductor.
Claim 9
Dependent Claim
43 words
A conductor comprising several intertwined strands in which each strand is supplied with individual grooves and given a chemical treatment to provide a wetting surface, said grooves acting as capillaries to convey moisture from the surface of the conductor to the interior thereof.
Claim 10
Dependent Claim
43 words
A conductor comprising several intertwined strands in which each strand is supplied with individual grooves and given a chemical treatment to provide a wetting surface, said grooves acting as capillaries to convey moisture from the surface of the conductor to the interior thereof.
Claim 11
Dependent Claim
16 words
A conductor as claimed under 8 in which some of the strands comprise an absorbing material.
Claim 12
Dependent Claim
26 words
A conductor as claimed under 8 having a drain spout and in which the free spaces between the strands act as transport channels toward the spout.
Claim 13
Dependent Claim
70 words
An electrical conductor for use in a very high voltage or an ultra-high voltage system that comprises: a plurality of conductive strands bound together, the outer surface of the conductor having a conductivity of at least the order of 10 7 mhos per meter and said outer surface being moisture-absorbent so that moisture is drawn by capillary action from said outer surface and toward the longitudinal axis of the conductor.
Claim 14
Dependent Claim
70 words
An electrical conductor for use in a very high voltage or an ultra-high voltage system that comprises: a plurality of conductive strands bound together, the outer surface of the conductor having a conductivity of at least the order of 10 7 mhos per meter and said outer surface being moisture-absorbent so that moisture is drawn by capillary action from said outer surface and toward the longitudinal axis of the conductor.
Claim 15
Dependent Claim
35 words
An electrical conductor as claimed in claim 11 in which the whole of the outer surface of said strands contains transverse grooves having widths small enough so that capillary action occurs at said outer surface.
Claim 16
Dependent Claim
49 words
An electrical conductor as claimed in claim 11 in which the conductor comprises a plurality of layers of said strands, the strands having transverse grooves over the whole periphery thereof, the grooves being small enough to provide capillary action with respect to water drops in contact with said periphery.
Claim 17
Dependent Claim
61 words
An electrical conductor for use as an overhead transmission line in a very-high voltage or an ultra-high voltage system, that comprises, an electrical conductor having disposed on its surface a layer of water-absorbent material that effects transport by capillary action of any water at said surface toward the longitudinal axis of the conductor, and means electrically shielding the water absorbent layer.
Claim 18
Dependent Claim
61 words
An electrical conductor for use as an overhead transmission line in a very-high voltage or an ultra-high voltage system, that comprises, an electrical conductor having disposed on its surface a layer of water-absorbent material that effects transport by capillary action of any water at said surface toward the longitudinal axis of the conductor, and means electrically shielding the water absorbent layer.
Claim 19
Dependent Claim
92 words
A very high voltage or ultra-high voltage overhead transmission line system that comprises: a plurality of electrical towers, a plurality of electrical conductors, and insulation means mechanically connecting each electrical conductor to each tower and electrically insulating each conductor from each tower, each electrical conductor comprising conductive means and means for removing moisture from the outer surface of the electrical conductor and toward the axis of the electrical conductor, the last named means comprising means to effect transport of the moisture from said outer surface and toward said axis by capillary action.
Claim 20
Dependent Claim
92 words
A very high voltage or ultra-high voltage overhead transmission line system that comprises: a plurality of electrical towers, a plurality of electrical conductors, and insulation means mechanically connecting each electrical conductor to each tower and electrically insulating each conductor from each tower, each electrical conductor comprising conductive means and means for removing moisture from the outer surface of the electrical conductor and toward the axis of the electrical conductor, the last named means comprising means to effect transport of the moisture from said outer surface and toward said axis by capillary action.
Claim 21
Dependent Claim
68 words
An electrical conductor for overhead transmission lines for systems of at least 138 kV, that comprises: a central electrical conductor, an electrically conductive, water absorbent layer disposed upon the surface of the central conductor, and longitudinally extending water-transport channel means inside the layer, said water absorbent layer aCting through capillary action to absorb water at said surface and to transport the water, thus absorbed, to said channel means.
Claim 22
Dependent Claim
68 words
An electrical conductor for overhead transmission lines for systems of at least 138 kV, that comprises: a central electrical conductor, an electrically conductive, water absorbent layer disposed upon the surface of the central conductor, and longitudinally extending water-transport channel means inside the layer, said water absorbent layer aCting through capillary action to absorb water at said surface and to transport the water, thus absorbed, to said channel means.
Claim 23
Dependent Claim
20 words
An electrical conductor as claimed in claim 16 that includes means for creating a slight vacuum within the channel means.
Claim 24
Dependent Claim
22 words
An electrical conductor as claimed in claim 17 that includes at least one moisture-drainage spout for each span of the transmission line.
Claim 25
Dependent Claim
75 words
An electrical conductor for overhead transmission lines for systems of at least 138 kV, that comprises: an inner electrical conductor, and electrically conductive, porous layer means disposed upon the surface of the inner conductor, said porous layer means acting to remove water from said surface during foul weather, to draw the water by capillary action inside the electrically conductive porous layer means, and to effect electrical shielding of the water within said porous layer means.
Claim 26
Dependent Claim
75 words
An electrical conductor for overhead transmission lines for systems of at least 138 kV, that comprises: an inner electrical conductor, and electrically conductive, porous layer means disposed upon the surface of the inner conductor, said porous layer means acting to remove water from said surface during foul weather, to draw the water by capillary action inside the electrically conductive porous layer means, and to effect electrical shielding of the water within said porous layer means.
Claim 27
Dependent Claim
31 words
An electrical conductor as claimed in claim 19 in which the conductivity is at least the order of 10 7 mhos per meter at the outer surface of the porous layer.
Claim 28
Dependent Claim
76 words
A composite electrical conductor for overhead transmission lines for 138 kV and above that comprises: inner electrically conductive means; water-absorbent means associated with the conductive means; and an electrically conductive, porous layer at the outer surface of the electrical conductor, said water-absorbent means acting to draw water from said outer surface into the interior of the water-absorbent means, where the water is stored, and acting as well to remove the same to a point of drainage.
Claim 29
Dependent Claim
76 words
A composite electrical conductor for overhead transmission lines for 138 kV and above that comprises: inner electrically conductive means; water-absorbent means associated with the conductive means; and an electrically conductive, porous layer at the outer surface of the electrical conductor, said water-absorbent means acting to draw water from said outer surface into the interior of the water-absorbent means, where the water is stored, and acting as well to remove the same to a point of drainage.
Claim 30
Independent Claim
73 words
A method of reducing corona discharge from outdoor high voltage conductors of a transmission line during conditions of rain and fog, that comprises, drawing water drops that form on the outer surface of each conductor of the transmission line from said outer surface toward the interior of the conductor, transporting the water longitudinally within the conductor to a drainage site, and draining the water from the conductor under conditions of reduced electric field.
Claim 31
Independent Claim
73 words
A method of reducing corona discharge from outdoor high voltage conductors of a transmission line during conditions of rain and fog, that comprises, drawing water drops that form on the outer surface of each conductor of the transmission line from said outer surface toward the interior of the conductor, transporting the water longitudinally within the conductor to a drainage site, and draining the water from the conductor under conditions of reduced electric field.
Claim 32
Dependent Claim
43 words
A conductor comprising several intertwined strands in which each strand is supplied with individual grooves and given an electrochemical treatment to provide a wetting surface, said grooves acting as capillaries to convey moisture from the surface of the conductor to the interior thereof.
Claim 33
Dependent Claim
43 words
A conductor comprising several intertwined strands in which each strand is supplied with individual grooves and given an electrochemical treatment to provide a wetting surface, said grooves acting as capillaries to convey moisture from the surface of the conductor to the interior thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |