US3710293A - Insulating member for transformer coils - Google Patents

Insulating member for transformer coils Download PDF

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Publication number
US3710293A
US3710293A US00239532A US3710293DA US3710293A US 3710293 A US3710293 A US 3710293A US 00239532 A US00239532 A US 00239532A US 3710293D A US3710293D A US 3710293DA US 3710293 A US3710293 A US 3710293A
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US
United States
Prior art keywords
layers
channel
insulating
pressboard
constructed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00239532A
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English (en)
Inventor
G Lazor
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Inc USA
Original Assignee
Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Application granted granted Critical
Publication of US3710293A publication Critical patent/US3710293A/en
Anticipated expiration legal-status Critical
Assigned to ABB POWER T&D COMPANY, INC., A DE CORP. reassignment ABB POWER T&D COMPANY, INC., A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION, A CORP. OF PA.
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/32—Insulating of coils, windings, or parts thereof
    • H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures

Definitions

  • ABSTRACT U-shaped channels extend around the edges of the coils of shell-form power transformers.
  • the channels are constructed of layers of crepe paper and pressboard with at least one layer of crepe paper separating adjacent layers of pressboard.
  • An adhesive is used to bond the layers together.
  • the edges of the channels are scarfed to form a scarfed joint with an adjacent channel.
  • the channel members which are positioned along a straight side of the coil are substantially straight.
  • the channel members which are positioned around a corner of the coil are curved to conform to the shape of the coil.
  • the pressboard is double-corrugated before being bent into shape to prevent folds and wrinkles at the edges.
  • Another arrangement is taught by U.S. Pat. No. 3,189,681, wherein the channel is constructed of a plurality of plies of a stretchable paper sheet material bonded together by a thermoplastic resin.
  • the stretchablepaper sheet allows the channel to be bent without causing folds and wrinkles at the edges.
  • the channel member lacks the desired mechanical strength for large channel members.
  • pressboard may be used, however, forming thick pressboard requires special techniques, such as double-corrugating.
  • the straight and curved channel members are normally constructed from separate materials, a joint exists where they abut around the edge of the coil. For mechanical and electrical reasons, it is desirable to maintain the joint gap as small as possible.
  • the joint gap is determined mainly by the spacing between the channel members. Since constant spacing is difficult to maintain, the joint gap varies with this type of channel member. I
  • the channels are formed from a plurality of layers of different materials.
  • One layer comprises a suitable crepe paper material.
  • Another layer comprises a suitable pressboard material.
  • Adhesive such as a thermoplastic resin, is applied to the layers to bond the layers together.
  • At least one layer of crepe paper separates layers of pressboard from each other, thereby providing a means for the pressboard layers to slip with respect to each other during the channel forming operation.
  • the channel member is inexpensive to construct and has excellent electrical and mechanical properties.
  • FIG. 1 is an elevational view, partly in section, of a transformer constructed with insulating channel members disposed on the transformer coils;
  • FIG. 2 is a view of an inner comer insulating channel member constructed according to the teachings of an embodiment of this invention
  • FIG. 2A is a view of an outer corner insulating channel member constructed according to the teachings of an embodiment of this invention.
  • FIG. 3 is a sectional view of the channel member shown in FIG. 2 taken along the line III-III;
  • FIG. 4 is a sectional view of an end of a channel member constructed according to another embodiment of this invention.
  • the transformer includes a casing 10, a laminated magnetic core 12, and a winding structure 14.
  • the magnetic core 12 is supported from the casing 10 by insulating blocks 16.
  • the winding structure 14 comprises a plurality of axially spaced pancake-type coils, such as the coil 18.
  • the coil 18 includes a plurality of conductor turns 20 which are spirally disposed in a substantially rectangular shape.
  • the inner edge of the pancake coil 18 is covered with insulating channel members, such as the straight channel 22 and the curved channel 24.
  • the outer edge of the pancake coil 18 is covered with insulating channel members, such as the straight channel 26 and the curved channel 28.
  • the channels butt or overlap each other to form joints, such as the joint 30.
  • the channel members are constructed of materials which insulate and hold the coil turns in position.
  • a view of a channel member, such as the inner curved channel 24, is shown in FIG. 2.
  • the channel 24 includes an axial side 32 which is positioned in the axial direction of the coil 18.
  • the channel 24 also includes radial sides 34 and 36 which extend outwardly from the axial side 32 in a direction parallel to the radial axis of the coil 18.
  • the channel 24 is substantially U-shaped and has a radius of curvature suitable for fitting closely around an inner corner of the coil 18.
  • the outward ends of the radial sides 34 and36 may have notches or scallops 38 therein which help prevent folds and wrinkles in the channel during its forming.
  • nel 28 includes an axial side 29 and radial sides 31 and 33.
  • the channel 28 is substantially U-shaped and has a radius of curvature suitable for fitting closely around an outer corner of the coil 18.
  • the inner ends of the radial sides 31 and 33 have scallops 35 therein which allow the channel 28 to be bent without the side 31 and 33 wrinkling.
  • FIG. 3 illustrates a channel construction arrangement according to one embodiment of this invention.
  • the axial. side 34 of the channel member 24 is constructed of a plurality of layers of insulating material.
  • the outside layers 40 and 42 may be any suitable material which stretches sufficiently during the forming process.
  • the flat insulating materials are formed into the U-shape of the channel member.
  • stretchable layers 44 and 48 are positioned between the layers 50, 52 and 54. The number of layers may be changed without departing from the scope of this invention.
  • Layers 40, 42, 44 and 48 are constructed of a suitable stretchable insulating materials, such as creped high density kraft paper having about 25 crimps per inch.
  • Layers 50, 52 and 54 are constructed'of a suitable substantially rigid insulating material, such as pressboard.
  • the pressboard may be corrugated to facilitate shap- J sistance to folds during the forming process by allowing the pressboard layers to slip with respect to each other.
  • the resulting channel has excellent mechanical strength and rigidity and is easily constructed.
  • crepe paper layer, or layers, between the pressboard layers allows the pressboard layers to slide with respect to each other during the forming operation.
  • the layers 40, 42, 44, 48, 50, 52 and 54 are cut to the same length to form a straight end 56 for forming a butt-type joint.
  • An embodiment of this invention for forming scarfed joints is illustrated in FIG. 4.
  • Layers 58, 60, 62 and 64 are constructed to stretchable insulating material, such as crepe paper.
  • Layers 66, 68 and 70 are constructed of a suitable material, such as pressj board.
  • the ends of the layers form a staggered at'tern which makes the end of the channel tapered, tha is, the middle layers are larger than the outer layers.
  • Other staggered patterns may be used to scarf the ends of the channel without departing from the spirit of the invention.
  • the pattern is arranged to mate with a scarfed end of an adjacent channel member to form a scarfed joint.
  • channel members disclosed herein provide electrical insulating structures with sufficient mechanical strength by utilizing the properties of different materials. Since numerous changes may be made in the above described apparatus and different embodiments of the invention may be made without departing from the spirit thereof, it is intended that all of the matter contained in the foregoing description,'or shown the accompanying drawings, shall be interpreted as illustrative rather than limiting.
  • Electrical inductive apparatus having a winding, said winding comprising a plurality of pancake-type substantially rectangular coils, insulating members disposed around the edges of said coils, each of said insulating members having a U-shaped cross-section with an axial side and two radial sides, said axial and radial sides being constructed of, a laminated insulating material comprising at least two layers of crepe p'ape'r separated by a layer of pressboard with an adhesive material applied to said layers.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Coils Of Transformers For General Uses (AREA)
  • Insulating Of Coils (AREA)
US00239532A 1972-03-30 1972-03-30 Insulating member for transformer coils Expired - Lifetime US3710293A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US23953272A 1972-03-30 1972-03-30

Publications (1)

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US3710293A true US3710293A (en) 1973-01-09

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Family Applications (1)

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US00239532A Expired - Lifetime US3710293A (en) 1972-03-30 1972-03-30 Insulating member for transformer coils

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US (1) US3710293A (es)
FR (1) FR2178202B3 (es)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4910863A (en) * 1989-02-01 1990-03-27 Asea Brown Boveri Inc. Method of making an amorphous metal transformer
DE3920732A1 (de) * 1989-06-24 1991-01-03 Asea Brown Boveri Elektrisches induktionsgeraet
DE10020228A1 (de) * 2000-04-25 2001-10-31 Abb Research Ltd Hochspannungsisolationssystem
WO2002101765A2 (en) * 2001-06-08 2002-12-19 Tyco Electronics Corporation Devices and methods for protecting windings around a sharp edged core
US6995646B1 (en) * 1997-02-03 2006-02-07 Abb Ab Transformer with voltage regulating means
US20110030987A1 (en) * 2007-12-27 2011-02-10 Olof Hjortstam Electric Insulation Material, An Electric Device Comprising The Insulation Material And A Transformer
US9024713B1 (en) 2012-08-09 2015-05-05 Power Distribution Products, Inc. Extreme duty encapsulated transformer coil with corrugated cooling ducts and method of making the same
EP2867012B2 (de) † 2012-06-29 2020-07-22 Weidmann Holding AG Isolationselement zur elektrischen isolation im hochspannungsbereich

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2354500A (en) * 1942-10-22 1944-07-25 Gen Electric Insulated coil
US2435093A (en) * 1946-12-07 1948-01-27 Melville F Mitschrich Electrical insulation
US2489853A (en) * 1944-12-18 1949-11-29 Gen Electric Insulated coil for electric apparatus
US2754355A (en) * 1952-02-08 1956-07-10 Allis Chalmers Mfg Co Crepe paper insulating elements
US3189681A (en) * 1960-03-11 1965-06-15 Westinghouse Electric Corp Angular channel-shaped coil insulation
US3351693A (en) * 1964-02-14 1967-11-07 Westinghouse Electric Corp Method of manufacturing electrical insulating structures

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2354500A (en) * 1942-10-22 1944-07-25 Gen Electric Insulated coil
US2489853A (en) * 1944-12-18 1949-11-29 Gen Electric Insulated coil for electric apparatus
US2435093A (en) * 1946-12-07 1948-01-27 Melville F Mitschrich Electrical insulation
US2754355A (en) * 1952-02-08 1956-07-10 Allis Chalmers Mfg Co Crepe paper insulating elements
US3189681A (en) * 1960-03-11 1965-06-15 Westinghouse Electric Corp Angular channel-shaped coil insulation
US3351693A (en) * 1964-02-14 1967-11-07 Westinghouse Electric Corp Method of manufacturing electrical insulating structures

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4910863A (en) * 1989-02-01 1990-03-27 Asea Brown Boveri Inc. Method of making an amorphous metal transformer
DE3920732A1 (de) * 1989-06-24 1991-01-03 Asea Brown Boveri Elektrisches induktionsgeraet
US6995646B1 (en) * 1997-02-03 2006-02-07 Abb Ab Transformer with voltage regulating means
EP1150313A2 (de) * 2000-04-25 2001-10-31 Abb Research Ltd. Hochspannungsisolationssystem
EP1150313A3 (de) * 2000-04-25 2002-05-29 Abb Research Ltd. Hochspannungsisolationssystem
US6791033B2 (en) * 2000-04-25 2004-09-14 Abb Research Ltd. High-voltage insulation system
DE10020228A1 (de) * 2000-04-25 2001-10-31 Abb Research Ltd Hochspannungsisolationssystem
WO2002101765A2 (en) * 2001-06-08 2002-12-19 Tyco Electronics Corporation Devices and methods for protecting windings around a sharp edged core
WO2002101765A3 (en) * 2001-06-08 2003-04-10 Tyco Electronics Corp Devices and methods for protecting windings around a sharp edged core
US6933828B2 (en) 2001-06-08 2005-08-23 Tyco Electronics Corporation Devices and methods for protecting windings around a sharp edged core
US20110030987A1 (en) * 2007-12-27 2011-02-10 Olof Hjortstam Electric Insulation Material, An Electric Device Comprising The Insulation Material And A Transformer
US8178780B2 (en) * 2007-12-27 2012-05-15 Abb Research Ltd. Electric insulation material, an electric device comprising the insulation material and a transformer
EP2867012B2 (de) † 2012-06-29 2020-07-22 Weidmann Holding AG Isolationselement zur elektrischen isolation im hochspannungsbereich
US9024713B1 (en) 2012-08-09 2015-05-05 Power Distribution Products, Inc. Extreme duty encapsulated transformer coil with corrugated cooling ducts and method of making the same

Also Published As

Publication number Publication date
FR2178202B3 (es) 1976-03-19
FR2178202A1 (es) 1973-11-09

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Date Code Title Description
AS Assignment

Owner name: ABB POWER T&D COMPANY, INC., A DE CORP., PENNSYLV

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION, A CORP. OF PA.;REEL/FRAME:005368/0692

Effective date: 19891229