US3750070A - Pressure ring for transformer windings - Google Patents
Pressure ring for transformer windings Download PDFInfo
- Publication number
- US3750070A US3750070A US00203226A US3750070DA US3750070A US 3750070 A US3750070 A US 3750070A US 00203226 A US00203226 A US 00203226A US 3750070D A US3750070D A US 3750070DA US 3750070 A US3750070 A US 3750070A
- Authority
- US
- United States
- Prior art keywords
- pressure ring
- magnetic
- body portion
- members
- radial
- 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
Links
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Classifications
-
- 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
- H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
- H01F27/303—Clamping coils, windings or parts thereof together
-
- 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
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
- H01F27/36—Electric or magnetic shields or screens
-
- 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
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
- H01F27/36—Electric or magnetic shields or screens
- H01F27/366—Electric or magnetic shields or screens made of ferromagnetic material
Definitions
- ABSTRACT Pressure ring apparatus for securing the windings of power transformers.
- the pressure ring includes a body portion with magnetic radial members positioned therein to direct the leakage flux from the winding structure back into the magnetic core.
- the radial members are constructed from a plurality of metallic laminations which are stacked with their edges perpendicular to the leakage flux.
- Other magnetic members may be positioned in the body portion to help direct the leakage flux into the radial members.
- one side of the pressure ring is stepped to conform to the shape of the yoke portion of the magnetic core.
- Pressure rings are used at the ends of the winding structures of power transformers to maintain the size and position of the winding structures when subject to high stress conditions.
- the pressure ring carries a substantial amount of flux when it is constructed from a magnetic material.
- the pressure rings may be constructed of a non-magnetic material which has magnetic radial members positioned therein to direct the leakage flux into the transformer core.
- the radial members are constructed of magnetic members, such as grain oriented magnetic steel strips, with the edges of the strips perpendicular to the longitudinal axis of the winding structure. Additional magnetic members may be positioned between the radial members to help bring the leakage flux into the radial members.
- the size and shape of the pressure ring depends upon the type and rating of the transformer and upon other factors. One portion of the pressure ring may be stepped to conform to the shape of the yoke portion of the magnetic core.
- FIG. I is a cutaway view of a power transformer having pressure rings constructed according to the teachings of this invention.
- FIG. 2 is a top view of a pressure ring constructed according to the teachings of one embodiment of this invention.
- FIG. 3 is a top view of a pressure ring constructed according to the teachings of another embodiment of this invention.
- FIG. 4 is a top view of a pressure ring constructed according to the teachings of still another embodiment of this invention.
- FIG. 5 is a partial elevational view of a transformer core of the flat-yoke type having installed thereon a pressure ring constructed according to the teachings of this invention
- FIG. 6 is a partial elevational view of a transformer core of the stepped-yoke type having installed thereon a pressure ring constructed according to the teachings of this invention.
- FIG. 7 is an isometric view of the pressure ring shown in FIG. 6.
- FIG. I there is shown a power transformer having a casing 110, a magnetic core 12, and longitudinal, hollow, winding structures M, 16 and 18.
- the casing 10 contains a fluid collant 20 and supports the high voltage bushings 22, 24 and 26 and the low voltage bushing 2%. Although they would normally be present, the lower structures of the bushings and the winding leads are not illustrated for clarity.
- the top end frame 30 and the bottom end frame 32 support the magnetic core 12 and the winding structures I4, 16 and I8. Insulating material 34 is placed between each winding structure and the end frames.
- Pressure rings 36, 38 and 40 are illustrated adjacent to the top ends of the winding structures I4, 16 and 18, re spectively. Similar rings are located adjacent to the lower ends of each winding structure. The detailed construction of the pressure rings will be described hereinafter. The leakage flux existing near the ends of the winding structures enters the pressure rings and is directed back into the magnetic core l2.
- FIG. 2 is a top view of a pressure ring constructed according to an embodiment of this invention and positioned around a leg 42 of a cruciform-type magnetic core.
- the pressure ring is substantially circumferential and includes a body portion 44 having a central opening 45 and a plurality of magnetic radial members 46 mounted in the body portion 44.
- the radial members 46 may comprise a plurality of metallic laminations dd which are placed in the body portion 44. The number of laminations per radial member 46, the number of radial members 46, and the average separation distance d between the radial members 46 is dependent upon the type and rating of the transformer.
- the body portion 50 of the pressure ring shown in FIG. 3 contains radial members 52 which have more laminations 54 per radial member than the arrangement shown in FIG. 2.
- the average separation distance D is greater than the arrangement shown in FIG. 2.
- the pressure ring embodiments illustrated in FIGS. 2 and 3 operate in substantially the same manner.
- the leakage flux at the end of the winding structures is oriented in an axial direction. This causes the flux to enter the edges of the laminations forming the radial members.
- the flux is carried in a radial direction into the core leg 42 where it may reinforce the flux already in the core to increase the coupling between the coils of the winding structure, thus increasing the efficiency of the transformer.
- This also prevents the leakage flux from entering the end frame and casing to generate undesired heat in the end frame and easing. Heat generated in the end frames and the casing constitutes a power loss and also causes rapid deterioration of the insulation.
- FIGS. 2 and 3 may have magnetic members disposed in a circular arrangement between the radial members.
- FIG. 4 illustrates an embodiment of the pressure ring shown in-FIG. 3 wherein the magnetic members 56 are placed between the radial members 52.
- Each magnetic member 56 is constructed of a plurality of metallic laminations 58.
- the members 56 direct the flux into the radial members 52 where it is then directed into the magnetic core leg 42.
- the number of laminations 58, the size of the members 56, the radial location of the members 56, and other variables may be altered without departing from the teachings of this invention.
- the members 56 shown in FIG. 4 are radially positioned near the center of the pressure ring body portion 50 since a high concentration of leakage flux occurs in this region due to the separation of the high and low voltage windings of the winding structure.
- FIG. 5 is a partial side elevational view illustrating a mounting arrangement of the pressure ring 40.
- the pressure ring 40 is mounted adjacent to the bottom end of the winding structure 62 with an insulating member 64 therebetween.
- the mounting arrangement for the upper pressure ring is substantially similar.
- Pressure producing means which forces the pressure rings against the winding structure 62 is not shown.
- the pressure ring 40 is supported by the end frame members 32.
- the side 41 of the pressure ring 40 is substantially flat.
- the lower portion 42 is also substantially flat and rests on the flanges 33 and the top portion of the bottom magnetic core yoke.
- the laminations 66 are located in the pressure ring 40 with their edges perpendicular to the longitudinal axis of the winding structure 62. This permits each lamination 66 to receive leakage flux through its edge.
- the pressure ring 68 illustrated in FIG. 6 is associated with a magnetic core having a yoke section with a stepped upper portion. That is, the yoke has a cruciformtype cross-section similar to the core legs.
- the winding structure 70 is separated from the pressure ring 68 by the insulating material 72.
- the pressure ring 68 rests on the flanges 74 of the end frame members 76 and also on the stepped portions of the magnetic core yoke.
- the upper portion 78 of the pressure ring 68 is substantially flat and is located approximately even with the upper portion of the magnetic core yoke.
- the lower portion of the pressure ring 68 is stepped to permit its placement around the yoke with a sufficient area thereof resting on the yoke to provide adequate mechanical strength.
- the pressure ring 68 does not be cupy any space between the top portion of the yoke and the winding structure.
- the laminations may have a width dimension w equal to the stepped dimension s without requiring any extension of the pressure ring 68 above the upper portion of the yoke surface.
- FIG. 7 An isometric view of the pressure ring 68 is shown in FIG. 7.
- the upper portion 82 of the yoke is flush with the upper portion 78 of the pressure ring 68.
- the radlal members 84 are formed from a plurality of laminations 80. A radial member is not required over the yoke portion 82 since the yoke portion effectively catches the leakage flux at that location.
- the pressure ring 68 is shown with a gap equal to the width of the upper yoke portion 82, the ring may be constructed without any gap if strength considerations require such. In such a case, the upper portion 78 of the pressure ring 68 would be above the upper portion 82 of the yoke.
- the pressure ring 68 may be constructed of a non-magnetic material.
- a suitable material would consist of a laminated fibrous material, such as wood, having an epoxide as a bonding material.
- a pressure ring for installation adjacent to an end of a transformer winding structure comprising a nonmagnetic body portion having upper and lower surfaces, the lower surface of said body portion having steps therein which conform to the shape of the magnetic core of the transformer, and magnetic members all aligned generally in a radial direction through said body portion, said magnetic members being positioned in grooves formed in said non-magnetic body portion.
- the pressure ring of claim 1 wherein the body portion is constructed of laminated fibrous material bonded together by an epoxide.
- the pressure ring of claim 1 wherein the magnetic members are constructed of a plurality of laminated magnetic strips, said strips positioned with their edges perpendicular to the longitudinal axis of the winding structure.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Coils Of Transformers For General Uses (AREA)
- Regulation Of General Use Transformers (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US20322671A | 1971-11-30 | 1971-11-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3750070A true US3750070A (en) | 1973-07-31 |
Family
ID=22753049
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00203226A Expired - Lifetime US3750070A (en) | 1971-11-30 | 1971-11-30 | Pressure ring for transformer windings |
Country Status (3)
Country | Link |
---|---|
US (1) | US3750070A (ja) |
JP (1) | JPS522006Y2 (ja) |
FR (1) | FR2162054B1 (ja) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3839133A (en) * | 1973-07-09 | 1974-10-01 | Permali Inc | Transformer insulating end ring |
US4012706A (en) * | 1975-12-08 | 1977-03-15 | General Electric Company | Sheet-wound transformer coils |
US4021764A (en) * | 1975-12-08 | 1977-05-03 | General Electric Company | Sheet-wound transformer coils with reduced edge heating |
DE2728905A1 (de) * | 1977-06-27 | 1979-01-18 | Transformatoren Union Ag | Transformator mit grossem streukanal und grossem streuflussanteil |
US4257025A (en) * | 1978-06-12 | 1981-03-17 | Asea Aktiebolag | Laminated metallic plates for supporting core leg in inductive electrical devices to determine magnetic circuit |
US4656452A (en) * | 1985-11-08 | 1987-04-07 | Rte Corporation | Transformer telephone influence tractor core shunt |
US5604971A (en) * | 1993-09-30 | 1997-02-25 | Steiner; Robert E. | manufacturing method for variable laminations used in electro-magnetic induction devices |
US5640752A (en) * | 1993-09-30 | 1997-06-24 | Steiner; Robert E. | Controlled adjustable manufacturing method for variable laminations used in electro-magnetic induction devices |
WO2001063636A2 (en) * | 2000-02-23 | 2001-08-30 | Abb Technology Ag | Leakage flux protection for transformer clamping bar |
CN102315004A (zh) * | 2010-06-30 | 2012-01-11 | 特变电工沈阳变压器集团有限公司 | 一种变压器的磁屏蔽结构及磁屏蔽方法 |
US20130106547A1 (en) * | 2011-11-01 | 2013-05-02 | Hitachi Industrial Equipment Systems Co., Ltd. | Amorphous Core Transformer |
US20180174744A1 (en) * | 2016-12-21 | 2018-06-21 | Fanuc Corporation | Multi-phase transformer |
US20180204670A1 (en) * | 2017-01-19 | 2018-07-19 | Hitachi, Ltd. | Stationary Induction Apparatus |
NL2019276B1 (nl) * | 2017-07-19 | 2019-02-12 | Royal Smit Transf B V | Hoogvermogen inductief element |
US10629355B2 (en) * | 2017-06-08 | 2020-04-21 | Hitachi, Ltd. | Stationary induction apparatus |
EP4040455A1 (en) * | 2021-02-05 | 2022-08-10 | Hitachi Energy Switzerland AG | Transformer comprising winding |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2896182A (en) * | 1955-09-17 | 1959-07-21 | Pruneau Pierre Marie | Magnetic circuits for stationary electrical induction apparatus |
FR1201855A (fr) * | 1957-09-18 | 1960-01-06 | Siemens Ag | Dispositif pour diminuer, au moyen d' <éléments de dispersion>, les pertes provoquées par les champs de fuite dans les transformateurs et les bobines de réactance |
US2962679A (en) * | 1955-07-25 | 1960-11-29 | Gen Electric | Coaxial core inductive structures |
FR1401109A (fr) * | 1964-07-20 | 1965-05-28 | Oerlikon Maschf | élément de dispersion feuilleté pour transformateurs, bobines de réactance, et analogues |
CA732318A (en) * | 1966-04-12 | T. Wilkins John | Transformers | |
US3366907A (en) * | 1965-10-22 | 1968-01-30 | Westinghouse Electric Corp | Core-form transformer pressure ring wound from magnetic material |
US3467932A (en) * | 1967-07-28 | 1969-09-16 | Westinghouse Electric Corp | Transformer construction |
GB1245197A (en) * | 1969-03-05 | 1971-09-08 | Asea Ab | Improvements in iron cores for inductive electrical apparatus |
US3639872A (en) * | 1968-05-30 | 1972-02-01 | Asea Ab | Means for controlling the leakage flux in transformers |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1115862A (en) * | 1964-03-04 | 1968-05-29 | English Electric Co Ltd | Improvements in or relating to inductive apparatus |
-
1971
- 1971-11-30 US US00203226A patent/US3750070A/en not_active Expired - Lifetime
-
1972
- 1972-11-28 JP JP1972136218U patent/JPS522006Y2/ja not_active Expired
- 1972-11-29 FR FR7242409A patent/FR2162054B1/fr not_active Expired
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA732318A (en) * | 1966-04-12 | T. Wilkins John | Transformers | |
US2962679A (en) * | 1955-07-25 | 1960-11-29 | Gen Electric | Coaxial core inductive structures |
US2896182A (en) * | 1955-09-17 | 1959-07-21 | Pruneau Pierre Marie | Magnetic circuits for stationary electrical induction apparatus |
FR1201855A (fr) * | 1957-09-18 | 1960-01-06 | Siemens Ag | Dispositif pour diminuer, au moyen d' <éléments de dispersion>, les pertes provoquées par les champs de fuite dans les transformateurs et les bobines de réactance |
FR1401109A (fr) * | 1964-07-20 | 1965-05-28 | Oerlikon Maschf | élément de dispersion feuilleté pour transformateurs, bobines de réactance, et analogues |
US3366907A (en) * | 1965-10-22 | 1968-01-30 | Westinghouse Electric Corp | Core-form transformer pressure ring wound from magnetic material |
US3467932A (en) * | 1967-07-28 | 1969-09-16 | Westinghouse Electric Corp | Transformer construction |
US3639872A (en) * | 1968-05-30 | 1972-02-01 | Asea Ab | Means for controlling the leakage flux in transformers |
GB1245197A (en) * | 1969-03-05 | 1971-09-08 | Asea Ab | Improvements in iron cores for inductive electrical apparatus |
Cited By (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3839133A (en) * | 1973-07-09 | 1974-10-01 | Permali Inc | Transformer insulating end ring |
US4012706A (en) * | 1975-12-08 | 1977-03-15 | General Electric Company | Sheet-wound transformer coils |
US4021764A (en) * | 1975-12-08 | 1977-05-03 | General Electric Company | Sheet-wound transformer coils with reduced edge heating |
DE2728905A1 (de) * | 1977-06-27 | 1979-01-18 | Transformatoren Union Ag | Transformator mit grossem streukanal und grossem streuflussanteil |
US4257025A (en) * | 1978-06-12 | 1981-03-17 | Asea Aktiebolag | Laminated metallic plates for supporting core leg in inductive electrical devices to determine magnetic circuit |
US4656452A (en) * | 1985-11-08 | 1987-04-07 | Rte Corporation | Transformer telephone influence tractor core shunt |
US5604971A (en) * | 1993-09-30 | 1997-02-25 | Steiner; Robert E. | manufacturing method for variable laminations used in electro-magnetic induction devices |
US5640752A (en) * | 1993-09-30 | 1997-06-24 | Steiner; Robert E. | Controlled adjustable manufacturing method for variable laminations used in electro-magnetic induction devices |
WO2001063636A2 (en) * | 2000-02-23 | 2001-08-30 | Abb Technology Ag | Leakage flux protection for transformer clamping bar |
WO2001063636A3 (en) * | 2000-02-23 | 2002-01-10 | Abb Transmit Oy | Leakage flux protection for transformer clamping bar |
CN102315004A (zh) * | 2010-06-30 | 2012-01-11 | 特变电工沈阳变压器集团有限公司 | 一种变压器的磁屏蔽结构及磁屏蔽方法 |
CN102315004B (zh) * | 2010-06-30 | 2013-06-12 | 特变电工沈阳变压器集团有限公司 | 一种变压器的磁屏蔽结构及磁屏蔽方法 |
US20130106547A1 (en) * | 2011-11-01 | 2013-05-02 | Hitachi Industrial Equipment Systems Co., Ltd. | Amorphous Core Transformer |
US9105393B2 (en) * | 2011-11-01 | 2015-08-11 | Hitachi Industrial Equipment Systems Co., Ltd. | Amorphous core transformer |
US20180174744A1 (en) * | 2016-12-21 | 2018-06-21 | Fanuc Corporation | Multi-phase transformer |
US20180204670A1 (en) * | 2017-01-19 | 2018-07-19 | Hitachi, Ltd. | Stationary Induction Apparatus |
US10665382B2 (en) * | 2017-01-19 | 2020-05-26 | Hitachi, Ltd. | Stationary induction apparatus |
US10629355B2 (en) * | 2017-06-08 | 2020-04-21 | Hitachi, Ltd. | Stationary induction apparatus |
NL2019276B1 (nl) * | 2017-07-19 | 2019-02-12 | Royal Smit Transf B V | Hoogvermogen inductief element |
EP4040455A1 (en) * | 2021-02-05 | 2022-08-10 | Hitachi Energy Switzerland AG | Transformer comprising winding |
WO2022167622A1 (en) * | 2021-02-05 | 2022-08-11 | Hitachi Energy Switzerland Ag | Transformer comprising winding |
US11990268B2 (en) | 2021-02-05 | 2024-05-21 | Hitachi Energy Ltd | Transformer comprising winding |
Also Published As
Publication number | Publication date |
---|---|
FR2162054B1 (ja) | 1976-08-20 |
JPS522006Y2 (ja) | 1977-01-18 |
FR2162054A1 (ja) | 1973-07-13 |
JPS4871313U (ja) | 1973-09-07 |
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Legal Events
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 |