EP0408230A2 - Conducteurs de litz fermant des brins de câble semi-comprimés, et séparés, pour permettre le refroidissement entre les brins individuels isolés - Google Patents

Conducteurs de litz fermant des brins de câble semi-comprimés, et séparés, pour permettre le refroidissement entre les brins individuels isolés Download PDF

Info

Publication number
EP0408230A2
EP0408230A2 EP90307224A EP90307224A EP0408230A2 EP 0408230 A2 EP0408230 A2 EP 0408230A2 EP 90307224 A EP90307224 A EP 90307224A EP 90307224 A EP90307224 A EP 90307224A EP 0408230 A2 EP0408230 A2 EP 0408230A2
Authority
EP
European Patent Office
Prior art keywords
strands
compacted
semi
bundle
coil
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.)
Withdrawn
Application number
EP90307224A
Other languages
German (de)
English (en)
Other versions
EP0408230A3 (en
Inventor
Steven Robert Walk
Robert Michael Del Vecchio
Robert Michael Slepian
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.)
Westinghouse Electric Corp
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
Publication of EP0408230A2 publication Critical patent/EP0408230A2/fr
Publication of EP0408230A3 publication Critical patent/EP0408230A3/en
Withdrawn legal-status Critical Current

Links

Images

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
    • H01F27/08—Cooling; Ventilating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F5/00—Coils
    • 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
    • H01B7/42—Insulated conductors or cables characterised by their form with arrangements for heat dissipation or conduction
    • H01B7/421—Insulated conductors or cables characterised by their form with arrangements for heat dissipation or conduction for heat dissipation
    • H01B7/423—Insulated conductors or cables characterised by their form with arrangements for heat dissipation or conduction for heat dissipation using a cooling fluid
    • H01B7/425—Insulated conductors or cables characterised by their form with arrangements for heat dissipation or conduction for heat dissipation using a cooling fluid the construction being bendable
    • 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
    • H01F27/2823—Wires

Definitions

  • the present invention relates generally to electromagnetic (EM) induction coils for magnetofluidyna­mic (MFD) devices and, more particularly, is concerned with semi-compacted Litz wire cable strands spaced for coolant flow about individual insulated strands.
  • EM electromagnetic
  • MMD magnetofluidyna­mic
  • the overall effect on the terminal resistance of a coil can be dramatic.
  • data taken from a solenoidal coil (5 turns per layer, 6 layers, 88.4 x 44.45 millimeters in cross-section) showed that the coil resistance at 100 kHz has increased nearly two orders of magnitude over the actual DC resistance of the coil conductors.
  • the effective resistance due to frequency effects in the coil was on the order of 10 to 35 times the DC base value.
  • the ultimate result is that standard multi-turn conductor coils develop such high ohmic heating at medium to high frequencies that providing cooling to the individual conductors becomes increasingly difficult. Hot conductors can mean increased power loss, deteriorating insulation, or thermal instability conditions.
  • the above method can work well assuming a liquid heat transfer medium is used, such as water.
  • a liquid heat transfer medium such as water.
  • the finned-sheet coil method provides only marginal ability to cool the conductors by gas coolant methods.
  • Transposed stranded wire conductors are commercial strictlyly available under the name Litzendrant conductor, or Litz-wire.
  • the Litz-wire cable is formed by transposing individual insulated strands or wires within small groups of wires and then transposing the groups within the cable.
  • the immediate effect of this cabling method is to equalize the flux linkages of each individual strand, thus causing the current to divide evenly among the strands.
  • Ohmic heating is lower, approaching D.C. values, and is more evenly distributed in the coil volume. This allows easier and more efficient heat removal as compared to sheet or ribbon, or solid or hollow conductor, winding configurations.
  • Cooling techniques previously employed in insulated stranded wire induction coils have included compacted Litz-wire cable (the usual manufactured form) contained in a jacket or sheath, into which water is injected. The water is directed to flow either outside the compact bundle or through a center channel around which the insulated multiple strands of Litz-wire have been compressed.
  • the heat transfer capability of these cooling techniques are substantially less than optimal.
  • the present invention provides a Litz-wire cable composed of a semi-compacted insulated multiple strand bundle designed to satisfy the aforementioned needs.
  • the semi-compacted strand bundle of the present invention provides space for coolant flow therethrough about individual strands to both minimize coil losses and enhance heat transfer capability for optimal performance of induction coils used in MFD devices.
  • the invention in its broad form is a electromag­netic induction coil for a magnetofluidynamic device, characterized by a cable composed of multiple individual­ly-insulated conductor strands wound in Litz-wire fashion in a relatively loose relationship to one another to form a semi-compacted bundle; and an insulator sheath enclosing the cable; the strands in the semi-compacted bundle defining a plurality of empty spaces between individual strands for permitting coolant flow within the sheath and through the bundle along and about the individual strands such that the amount of surface area of the strands exposed to contact by the coolant is greater than in a compacted bundle of strands thereby enhancing the heat transfer capability of the cable.
  • the empty space between individual strands in the semi-compacted bundle is from two to three times more than in a compacted bundle of the same strands.
  • the semi-compacted insulated conductor strands fill from 40 to 50 percent of the cross-sectional area within the sheath and are uniformly distributed across the cross-sectional area of the sheath.
  • the present invention is directed to a magnetofluidynamic device which comprises: (a) the above-defined electromagnetic induction coil; and (b) a holder composed of non-conductive material having channels therein for housing the coil.
  • the coil strands in the semi-compacted bundle define a plurality of empty spaces between individual strands for permitting coolant flow through the holder channels and bundle and along and about individual strands.
  • each strand 12 is composed of an inner cylindrical core in the form of an electrical conductor 14 and an outer cylindri­cal layer 16 of insulating material enclosing the conductor 14.
  • each of the strands 12 of the cable 10 is insulated from one another.
  • the multiple insulated strands 12 are wound together in a Litz-wire fashion.
  • the Litz-wire wound configuration is well-known and so need not be illustrated in the drawings.
  • the Litz-wire configuration is a helical pattern wherein each strand 12 of the bundle thereof assumes a transposed relation to others.
  • the transposed relation means that each strand 12 at one point along the cable 10 is located along the periphery of the bundle and at another point is located inwardly from the periphery of the bundle, whereby the current flow is substantially uniformly distributed through the strands 12 of the cable.
  • the bundle of strands 12 have been wound in a tightly compacted relation and wrapped by an insulator sheath 18 to retain them in the compacted bundle.
  • the insulated conductor strands fill from 75 to 85 percent of the cross-sectional area within the sheath.
  • steps are taken to form a central channel 20 through the center of the bundle of strands 12 for allowing coolant flow through the bundle center.
  • the central channel 20 can be merely the space remaining between the strands along the center of the cable 10 or defined by a tube (not shown) running along the center of the cable 10 around which the strands 12 are wound.
  • the heat transfer capability of the prior art Litz-wire cable 10 of Fig. 1 is enhanced by the modifica­tions introduced thereto in accordance with the principles of the present invention as embodied in the improved Litz-­wire wound cable 22 of Fig. 3.
  • the primary difference between the improved cable 22 of Fig. 3 and the prior art cable 10 of Fig. 1 is that in the improved cable 22 the bundle of multiple insulated conductor strands 24 are wound in a loose, semi-compacted relationship to one another.
  • a plurality of empty spaces 26 are defined between the individual strands 24 for permitting coolant flow through the bundle along and about the individual strands 24.
  • the empty space between individu­al strands 24 in the semi-compacted bundle is from two to three times more than in a compacted bundle of the same strands.
  • the semi-compacted insulated conductor strands 24 fill from 40 to 50 percent of the cross-­sectional area within the sheath 18 and are uniformly distributed across the cross-sectional area of the sheath.
  • the amount of surface area of the strands 24 now exposed to coolant is significantly greater in the improved cable 22 than in the prior art cable 10. Direct contact by the coolant with the increased amount of surface area of the individual strands 24 substantially increases and enhances the heat transfer capability of the cable 22.
  • the improved cable 22 has particular application to an electromagnetic induction coil for an magnetofluidy­namic (MFD) device, such as the electromagnetic valve or flow control device disclosed in U.S. Patent 4,842,170.
  • the coil composed of the semi-compacted insulated conductor strands has an A.C. excitation operating capacity within the frequency range of from 1 to 50 kHz, making it particularly suited for use in such application.
  • Fig. 4 shows a cross-section of a prior art annular MFD device 28 with an induction coil employing thin-sheet conductors 30 which are fin-cooled (only one conductor being shown).
  • the device 28 has channels 32 with a series of spaced fins 34 mounted therein past which coolant flows within the channels 32. Most of the current flows within the inner portion 30A of the conductor 30 such that almost no current flows through the fins 34 which directly contact the coolant resulting in less than optimal transfer of heat from the conductor 30 to the coolant.
  • Fig. 5 shows a MFD device 36 having an induction coil 38 employing the semi-compacted, spaced, multiple, Litz-wire wound, insulated strands 24 of the cable 22 of the present invention.
  • the device 36 includes a holder 40 composed of non-conductive material, such as glass or epoxy, and having channels 42 therein for housing the coil 38.
  • the insulated conductor strands 24 of the coil 38 are provided in the semi-compacted bundle as described above with respect to Fig. 3.
  • coolant such as a gas or liquid freon can flow through the spaces 26 within the bundle along and about individual strands 24 at reduced pressure compared to a compacted bundle of the same strands.
  • the amount of surface area of the semi-compacted strands 24 which is exposed to contact by the coolant is significantly greater than in a compacted bundle of the same strands thereby enhancing the heat transfer capability of the coil 38.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Coils Of Transformers For General Uses (AREA)
  • General Induction Heating (AREA)
  • Insulated Conductors (AREA)
  • Transformer Cooling (AREA)
  • Non-Insulated Conductors (AREA)
EP19900307224 1989-07-10 1990-07-02 Semi-compacted litz-wire cable strands spaced for coolant flow about individual insulated strands Withdrawn EP0408230A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US37769189A 1989-07-10 1989-07-10
US377691 1995-01-25

Publications (2)

Publication Number Publication Date
EP0408230A2 true EP0408230A2 (fr) 1991-01-16
EP0408230A3 EP0408230A3 (en) 1991-11-27

Family

ID=23490145

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900307224 Withdrawn EP0408230A3 (en) 1989-07-10 1990-07-02 Semi-compacted litz-wire cable strands spaced for coolant flow about individual insulated strands

Country Status (3)

Country Link
EP (1) EP0408230A3 (fr)
JP (1) JPH0352205A (fr)
KR (1) KR910003700A (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6092643A (en) * 1997-11-07 2000-07-25 Herzog; Kenneth Method and apparatus for determining stalling of a procession of moving articles
US6412252B1 (en) 1996-11-15 2002-07-02 Kaps-All Packaging Systems, Inc. Slotted induction heater
US6633480B1 (en) 1997-11-07 2003-10-14 Kenneth J. Herzog Air-cooled induction foil cap sealer
US6747252B2 (en) 1996-11-15 2004-06-08 Kenneth J. Herzog Multiple head induction sealer apparatus and method
US9172280B2 (en) 2011-11-21 2015-10-27 Aisin Aw Co., Ltd. Conductor and rotating electrical machine with a covering material
US9272157B2 (en) 2010-05-02 2016-03-01 Nervive, Inc. Modulating function of neural structures near the ear
US9339645B2 (en) 2010-05-02 2016-05-17 Nervive, Inc. Modulating function of the facial nerve system or related neural structures via the ear
FR3056012A1 (fr) * 2016-09-15 2018-03-16 Sncf Mobilites Dispositif de detection de circulation de liquide pour transformateur immerge
US10065047B2 (en) 2013-05-20 2018-09-04 Nervive, Inc. Coordinating emergency treatment of cardiac dysfunction and non-cardiac neural dysfunction
US20200168364A1 (en) * 2018-11-22 2020-05-28 Hitachi Metals, Ltd. Movable part composite cable

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH458467A (de) * 1966-03-23 1968-06-30 Siemens Ag Flüssigkeitskühlanordnung für elektrische Stromleiter, insbesondere für Supra- oder Kryoleiter
US3946349A (en) * 1971-05-03 1976-03-23 The United States Of America As Represented By The Secretary Of The Air Force High-power, low-loss high-frequency electrical coil
FR2233685B1 (fr) * 1973-06-12 1977-05-06 Josse Bernard
SU714511A1 (ru) * 1976-01-08 1980-02-05 Государственный Научно-Исследовательский Энергетический Институт Им. Г.М. Кржижановского Гибкий многофазный кабель переменного тока
SE7813174L (sv) * 1978-12-21 1980-06-22 Volvo Ab Stromledarkabel

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6412252B1 (en) 1996-11-15 2002-07-02 Kaps-All Packaging Systems, Inc. Slotted induction heater
US6629399B2 (en) 1996-11-15 2003-10-07 Kaps-All Packaging Systems Inc. Induction foil cap sealer employing litz wire coil
US6732495B2 (en) 1996-11-15 2004-05-11 Kaps-All Packaging Systems Inc. Induction foil cap sealer
US6747252B2 (en) 1996-11-15 2004-06-08 Kenneth J. Herzog Multiple head induction sealer apparatus and method
US7065941B2 (en) 1996-11-15 2006-06-27 Kaps-All Packaging Systems Inc. Induction foil cap sealer
US6633480B1 (en) 1997-11-07 2003-10-14 Kenneth J. Herzog Air-cooled induction foil cap sealer
US6092643A (en) * 1997-11-07 2000-07-25 Herzog; Kenneth Method and apparatus for determining stalling of a procession of moving articles
US6875965B2 (en) 2000-08-31 2005-04-05 Kenneth J. Herzog Multiple head induction sealer apparatus and method
US9339645B2 (en) 2010-05-02 2016-05-17 Nervive, Inc. Modulating function of the facial nerve system or related neural structures via the ear
US9272157B2 (en) 2010-05-02 2016-03-01 Nervive, Inc. Modulating function of neural structures near the ear
US10105549B2 (en) 2010-05-02 2018-10-23 Nervive, Inc. Modulating function of neural structures near the ear
US9172280B2 (en) 2011-11-21 2015-10-27 Aisin Aw Co., Ltd. Conductor and rotating electrical machine with a covering material
EP2738914A4 (fr) * 2011-11-21 2016-05-11 Aisin Aw Co Fil conducteur et machine électrique rotative
US10065047B2 (en) 2013-05-20 2018-09-04 Nervive, Inc. Coordinating emergency treatment of cardiac dysfunction and non-cardiac neural dysfunction
FR3056012A1 (fr) * 2016-09-15 2018-03-16 Sncf Mobilites Dispositif de detection de circulation de liquide pour transformateur immerge
US20200168364A1 (en) * 2018-11-22 2020-05-28 Hitachi Metals, Ltd. Movable part composite cable
US10818414B2 (en) * 2018-11-22 2020-10-27 Hitachi Metals, Ltd. Movable part composite cable

Also Published As

Publication number Publication date
KR910003700A (ko) 1991-02-28
EP0408230A3 (en) 1991-11-27
JPH0352205A (ja) 1991-03-06

Similar Documents

Publication Publication Date Title
US4079192A (en) Conductor for reducing leakage at high frequencies
US5304883A (en) Ring wound stator having variable cross section conductors
US7183678B2 (en) AC winding with integrated cooling system and method for making the same
EP1582092B1 (fr) Appareil de chauffage inductif et ohmique d'un objet
EP1405550B1 (fr) Procede et appareil pour le controle de la temperature d'un objet
EP0920107B1 (fr) Configuration d'enroulement pour un aternateur-démarreur interne basé sur une machine à reluctance commutée
US4897626A (en) Cooling electromagnetic devices
EP0080825A1 (fr) Enroulement d'armature plat en forme de spirale pour une machine électrique
US5430274A (en) Improvements made to the cooling of coils of an induction heating system
EP0408230A2 (fr) Conducteurs de litz fermant des brins de câble semi-comprimés, et séparés, pour permettre le refroidissement entre les brins individuels isolés
US20070090916A1 (en) Quad-gapped toroidal inductor
GB2025148A (en) Electrical transformers and reactors
CA2390335C (fr) Machine electrique a enroulement
EP0461109B1 (fr) Conducteur electrique toronne avec noyau de fils plats
CA1094179A (fr) Enroulements de transformateur feuillete a faible volume a distribution de temperature uniforme
CN100550223C (zh) 用于被液体冷却的绕组的导线以及变压器或扼流圈
JPH11102781A (ja) 高周波用強制冷却複合導体及び電磁誘導加熱コイル
EP1727263A2 (fr) Enroulement statorique refroidi par eau pour moteur eletrique
US4859978A (en) High-voltage windings for shell-form power transformers
US4460885A (en) Power transformer
EP1205020A1 (fr) Enroulement statorique refroidi par eau pour moteur electrique
US3668584A (en) Electrical power apparatus
RU198445U1 (ru) Комбинированная обмотка индукционного устройства
SU875486A1 (ru) Винтова обмотка индукционного аппарата
BG62541B1 (bg) Намотка на трансформатор за електросъпротивително заваряване

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): BE DE ES FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): BE DE ES FR GB IT

17P Request for examination filed

Effective date: 19911213

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19920623