US3609207A - High-voltage electrical cables - Google Patents

High-voltage electrical cables Download PDF

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Publication number
US3609207A
US3609207A US743778A US3609207DA US3609207A US 3609207 A US3609207 A US 3609207A US 743778 A US743778 A US 743778A US 3609207D A US3609207D A US 3609207DA US 3609207 A US3609207 A US 3609207A
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United States
Prior art keywords
protuberances
insulating
tapes
separating
layers
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Expired - Lifetime
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US743778A
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English (en)
Inventor
Gabriele Maschio
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Pirelli and C SpA
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Pirelli SpA
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Assigned to SOCIETA' PIRELLI S.P.A., A COMPANY OF ITALY reassignment SOCIETA' PIRELLI S.P.A., A COMPANY OF ITALY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: INDUSTRIE PIRELLI S.P.A.
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B9/00—Power cables
    • H01B9/06—Gas-pressure cables; Oil-pressure cables; Cables for use in conduits under fluid pressure
    • H01B9/0611—Oil-pressure cables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B7/00—Insulated conductors or cables characterised by their form
    • H01B7/02—Disposition of insulation
    • H01B7/0208—Cables with several layers of insulating material

Definitions

  • This invention relates to the insulation of high-voltage electrical cables and, more particularly, it concerns novel insulating arrangements for oil-filled electrical cables.
  • the present invention is especially useful in connection with electrical cables of the type shown and described in U.S. Pat. No. 3,223,773.
  • electrical cables which are suitable for both direct and alternating current, comprise a central electrical conductor and an insulation constituted by a plurality of tapings of synthetic plastic material helically wound about'the conductor.
  • An insulating oil such as mineral oil fills the spaces between the tapings.
  • separating insulating layers are interposed between the layers of synthetic plastic tape. These separating insulating layers are each constituted by a helical winding of single filaments, or of a fabric or braid of filaments of synthetic plastic material, resistant to oil and yet able to facilitate the passage of oil along them.
  • a dry inert gas for example, nitrogen or sulfur hexafluoride, has been substituted for the insulating oil.
  • separating insulating means constituted by layers made of single filaments or of a fabric or braid of filaments as has been known in the past, may give rise to some disadvantages. For instance, when filaments are used, it is impossible to carry out a rapid-winding operation, without at the same time subjecting the filaments to excessive tension. Moreover, when fabric tapes or braided filaments are employed, they suffer considerable elongation during the winding operation due to their low modulus of longitudinal elasticity.
  • the present invention provides novel insulating means for separating the layers of synthetic plastic insulating tape in such manner as to facilitate the passage of insulating fluid between the layers, without, however, suffering from the above-described disadvantage.
  • a high-voltage electric cable suitable for direct or alternating current, in which a dielectric insulation, which is stratified and impregnated with insulating fluid, is constituted by layers of synthetic plastic insulating tapes with interposed separating insulating means.
  • the separating insulating means are capable of providing good penetration of the insulating fluid throughout all of the hollow spaces existing between the layers.
  • the separating insulating means are constituted by tapes of synthetic plastic material having a substantially uniform thickness, and provided on at least one surface with a plurality of protuberances distributed uniformly thereabout. Additionally, recesses are provided on the opposite surface of the material in such a manner as to correspond to the protuberances.
  • FIG. 1 is a perspective view, with certain parts cut away, of an electric cable constructed in accordance with the present invention
  • FIG. 2 is a perspective view showing a portion of a separating layer used in the cable of FlG. l;
  • FIG. 3 is a view similar to FIG. 2 showing a modified configuration of the separating layer.
  • FIG. I there is shown a stranded electrical conductor 1 on to which is wound a screening tape 2 of a known type, such as a conductive tape.
  • a screening tape 2 of a known type, such as a conductive tape.
  • a first separating layer 3 constituted by a tape synthetic plastic material.
  • an impervious insulating tape 4 is wound around the first separating layer 3 .
  • the cable insulation is then built up by alternate separating layer 3 and insulating tapes 4 until the desired overall dielectric thickness is obtained.
  • the separating layers 3 are each formed with a plurality of protuberances 5 which are distributed uniformly thereabout. Corresponding recesses, not shown, are provided on the opposite sides of the separating layers 3.
  • the protuberances 5 (which are shown exaggerated in size), and their corresponding recesses extend over substantially the whole of the surface of the separating layers 3.
  • the separating layers 3 are constituted by tapes of synthetic plastic material, of substantially uniform thickness, wound about the cable in helical fashion.
  • the thickness of the tape comprising each of the layers 3 is generally between 0.04 and 0.20 millimeters.
  • the protuberances 5 have a height ranging between 0.01 and 0.20 millimeters.
  • protuberances 5 and their corresponding recesses may extend over the whole of the tape surface, nevertheless, portions of the surface are preferably left smooth between various protuberances. The spaces defined between protuberances and the intermediate smooth surface portions permit the passage of insulating fluid throughout the cable in which the separating layers 3 are used.
  • the modulus of longitudinal elasticity is unaffected so that the tape can be wound under considerable tension without the occurrence of excessive elongation or rupture.
  • the uniform thickness of the tape permits the attaining, after winding, of a high dielectric strength, nevertheless, the presence of the protuberances 5 on the tape surface reduces the modulus of elasticity to compression of the cable insulation in the radial direction. Consequently, radial pressures and the friction between the individual tapes is reduced. It is, therefore, possible to obtain an extremely flexible winding,
  • the protuberances 5 on the tape surface are round. Because of this rounded configuration, the protuberances 5 serve partially to reduce the concentration of electric stresses so that higher in-service voltages can be used.
  • the plurality of protuberances and associated recesses facilitates the passage of insulating fluid, permitting it to fill all of the hollow spaces existing between the layers of the insulating tapes of synthetic plastic material and thereby eliminating the presence of air or other gases of relatively low dielectric character.
  • the synthetic plastic materials used for the separating insulating layers 3 are selected from among those which have both good electrical and good mechanical characteristics, as for example, polypropylene, polytetrafluoroethylcne, polyethyleneterephthalate, polybutylene, polystyrene, polycarbonates and polysulphones.
  • the electrical characteristics of the fluid and tapes may be made consistent with each other, and they can be made to exhibit low dielectric losses even at the high operating temperatures of the cable (e.g., C.).
  • the above-listed synthetic plastic materials have a high dielectric strength.
  • these tapes are particularly suitable for oil-filled cables used with alternating current.
  • the separating insulating layers 3 are made by passing a film of a synthetic plastic material, selected among the above-listed polymers, between two cylinders, at least one of which is provided with appropriate projections about its surface.
  • the cylinders are heated, and as the film passes between them, the protuberances press into the film to form the desired configuration. Thereafter, the film is cut into tapes for winding about the cable.
  • FIG. 3 shows a modified insulating layer 3'.
  • the layer 3' which is also of synthetic plastic material, is formed with a plurality of protuberances 5 spaced apart from each other and having corresponding recesses on the opposite side of the tape. interspersed among the protuberances 5 are depressions 5' which are provided with corresponding protuberances on the opposite side of the tape.
  • the combination of the protuberances 5 and the depressions 5 serves to enhance the hollow space-forming characteristics of the tape and also serves to enhance the reduction in modulus of elasticity in the radial direction of the electrical cable with which the tape is used.
  • a high-voltage electric cable suitable for direct or alternating current, said cable comprising a central conductor surrounded by a dielectric, said dielectric being stratified, im-
  • separating insulating means which are physically different from said tapes and which permit the penetration and flow of said insulating fluid between the layers of insulating tapes
  • said separating insulating means being constituted by fluid impervious tapes of synthetic plastic material having practically a uniform thickness, and provided on at least one surface with a plurality of hollow, arcuate faced, fluid impervious protuberances spaced from each other both longitudinally and transversely of the tape and on the opposite surface with a plurality of concave recesses corresponding to said protuberances.

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  • Insulating Bodies (AREA)
  • Insulators (AREA)
  • Organic Insulating Materials (AREA)
  • Insulated Conductors (AREA)
US743778A 1961-03-31 1968-07-10 High-voltage electrical cables Expired - Lifetime US3609207A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT595061 1961-03-31
IT1847067 1967-07-17

Publications (1)

Publication Number Publication Date
US3609207A true US3609207A (en) 1971-09-28

Family

ID=11152907

Family Applications (2)

Application Number Title Priority Date Filing Date
US462089D Pending USB462089I5 (zh) 1961-03-31
US743778A Expired - Lifetime US3609207A (en) 1961-03-31 1968-07-10 High-voltage electrical cables

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US462089D Pending USB462089I5 (zh) 1961-03-31

Country Status (7)

Country Link
US (2) US3609207A (zh)
AT (1) AT280385B (zh)
BE (1) BE718149A (zh)
DE (1) DE1765725A1 (zh)
ES (1) ES356380A2 (zh)
FR (1) FR95367E (zh)
GB (1) GB1153610A (zh)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3814879A (en) * 1971-03-09 1974-06-04 Westinghouse Electric Corp Circuit interrupter with improved trap for removing particles from fluid insulating material
US3845233A (en) * 1973-02-12 1974-10-29 Dielectrics Int Ltd Pressurized insulant of solid and fluid for a conductor
US3928705A (en) * 1971-04-15 1975-12-23 Celanese Corp Dielectric insulation employing open-celled microporous film
US20120094553A1 (en) * 2009-06-12 2012-04-19 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd., Bus Bar and Connector
US20120285724A1 (en) * 2010-10-01 2012-11-15 Makoto Oya Insulated wire
WO2014173482A1 (de) * 2013-04-23 2014-10-30 Leoni Bordnetz-Systeme Gmbh Kabelsatz, wickelband sowie verfahren zur herstellung eines solchen kabelsatzes
US9355755B2 (en) 2011-04-07 2016-05-31 3M Innovative Properties Company High speed transmission cable
US20160336471A1 (en) * 2013-07-31 2016-11-17 (Fundant (Jiangsu) Advanced Materials Co., Ltd Photovoltaic interconnect wire
US20170066390A1 (en) * 2015-09-09 2017-03-09 Yazaki Corporation Wire harness
US10839981B2 (en) 2011-04-07 2020-11-17 3M Innovative Properties Company High speed transmission cable

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US463107A (en) * 1891-11-10 Sylvania
US471588A (en) * 1892-03-29 Insulated electric conductor
US1939264A (en) * 1930-02-05 1933-12-12 Callenders Cable & Const Co Electric cable
GB485400A (en) * 1935-12-13 1938-05-19 Siemens Ag Improvements in and relating to air-space-insulated high frequency electric cables
CA623731A (en) * 1961-07-11 C. De Vos Jan High-tension cable
US3223773A (en) * 1961-03-31 1965-12-14 Pirelli High-tension cable insulated with synthetic tape and oil
US3250850A (en) * 1961-02-17 1966-05-10 Moser Glaser & Co Ag Laminated insulating body

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US463107A (en) * 1891-11-10 Sylvania
US471588A (en) * 1892-03-29 Insulated electric conductor
CA623731A (en) * 1961-07-11 C. De Vos Jan High-tension cable
US1939264A (en) * 1930-02-05 1933-12-12 Callenders Cable & Const Co Electric cable
GB485400A (en) * 1935-12-13 1938-05-19 Siemens Ag Improvements in and relating to air-space-insulated high frequency electric cables
US3250850A (en) * 1961-02-17 1966-05-10 Moser Glaser & Co Ag Laminated insulating body
US3223773A (en) * 1961-03-31 1965-12-14 Pirelli High-tension cable insulated with synthetic tape and oil

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3898408A (en) * 1971-03-09 1975-08-05 Westinghouse Electric Corp Circuit interrupter with improved trap for removing particles from fluid insulating material
US3814879A (en) * 1971-03-09 1974-06-04 Westinghouse Electric Corp Circuit interrupter with improved trap for removing particles from fluid insulating material
US3928705A (en) * 1971-04-15 1975-12-23 Celanese Corp Dielectric insulation employing open-celled microporous film
US3845233A (en) * 1973-02-12 1974-10-29 Dielectrics Int Ltd Pressurized insulant of solid and fluid for a conductor
US20120094553A1 (en) * 2009-06-12 2012-04-19 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd., Bus Bar and Connector
US8500473B2 (en) * 2009-06-12 2013-08-06 Kobe Steel, Ltd. Bus bar and connector
US20120285724A1 (en) * 2010-10-01 2012-11-15 Makoto Oya Insulated wire
US9799425B2 (en) 2011-04-07 2017-10-24 3M Innovative Properties Company High speed transmission cable
US10839981B2 (en) 2011-04-07 2020-11-17 3M Innovative Properties Company High speed transmission cable
US9355755B2 (en) 2011-04-07 2016-05-31 3M Innovative Properties Company High speed transmission cable
US10726970B2 (en) 2011-04-07 2020-07-28 3M Innovative Properties Company High speed transmission cable
US10354778B2 (en) 2011-04-07 2019-07-16 3M Innovative Properties Company High speed transmission cable
US20160042834A1 (en) * 2013-04-23 2016-02-11 Leoni Bordnetz-Systeme Gmbh Cable set, winding tape and process for producing the cable set
US9831013B2 (en) * 2013-04-23 2017-11-28 Leoni Bordnetz-Systeme Gmbh Cable set, winding tape and process for producing the cable set
WO2014173482A1 (de) * 2013-04-23 2014-10-30 Leoni Bordnetz-Systeme Gmbh Kabelsatz, wickelband sowie verfahren zur herstellung eines solchen kabelsatzes
US9716198B2 (en) * 2013-07-31 2017-07-25 Fundant (Jiangsu) Advanced Materials Co., Ltd. Photovoltaic interconnect wire
US20160336471A1 (en) * 2013-07-31 2016-11-17 (Fundant (Jiangsu) Advanced Materials Co., Ltd Photovoltaic interconnect wire
US20170066390A1 (en) * 2015-09-09 2017-03-09 Yazaki Corporation Wire harness
US10647270B2 (en) * 2015-09-09 2020-05-12 Yazaki Corporation Wire harness

Also Published As

Publication number Publication date
DE1765725A1 (de) 1972-04-06
FR95367E (fr) 1970-09-11
ES356380A2 (es) 1970-01-01
GB1153610A (en) 1969-05-29
BE718149A (zh) 1969-01-17
AT280385B (de) 1970-04-10
USB462089I5 (zh)

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AS Assignment

Owner name: SOCIETA PIRELLI S.P.A., PIAZZALE CADORNA 5, 20123

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:INDUSTRIE PIRELLI S.P.A.;REEL/FRAME:003847/0084

Effective date: 19810101