US3792528A - Process of for manufacturing electrical apparatus such as casing-enclosed transformers and reactors - Google Patents

Process of for manufacturing electrical apparatus such as casing-enclosed transformers and reactors Download PDF

Info

Publication number
US3792528A
US3792528A US00250060A US3792528DA US3792528A US 3792528 A US3792528 A US 3792528A US 00250060 A US00250060 A US 00250060A US 3792528D A US3792528D A US 3792528DA US 3792528 A US3792528 A US 3792528A
Authority
US
United States
Prior art keywords
windings
coils
casing
electrical apparatus
sealing agent
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
US00250060A
Other languages
English (en)
Inventor
J Schober
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.)
BBC Brown Boveri AG Switzerland
BBC Brown Boveri France SA
Original Assignee
BBC Brown Boveri France SA
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 BBC Brown Boveri France SA filed Critical BBC Brown Boveri France SA
Application granted granted Critical
Publication of US3792528A publication Critical patent/US3792528A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/32—Insulating of coils, windings, or parts thereof
    • H01F27/323—Insulation between winding turns, between winding layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
    • H01F41/12—Insulating of windings
    • H01F41/122—Insulating between turns or between winding layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49071—Electromagnet, transformer or inductor by winding or coiling

Definitions

  • the apparatus for washing the sealing agent from thewindings and drying them includes a combined boiler-still in which the washing medium, e.g. kerosene, is heated to vaporization and delivered hot to the casing which serves to wash out the sealing agent and form a slurry with the latter.
  • the heat from the vapor also serves to heat up and dry the windings.
  • This slurry is pumped from the casing, passed through a filter anddelivered to a combined storage tank-still from which it is pumped back to the boiler-still for re-vaporization of the washing medium and recovery of the sealing agent which is then drained off for re-use to seal other windings.
  • a vacuum pump connected to the casing through a cooling trap serves to maintain the casing under a vacuum and also deliver water drawn off at the same time, from the cooling trap to the storage tank-still.
  • Vaporized washing medium is also selectively delivered from the boiler-still to a condenser, and the condensed washing medium is then passed into a storage tank having an outlet by means of which the washing medium can be delivered through an equalizing conduit to the storage tank-still.
  • the function of the storage tank for the condensed washing medium and equalizing conduit is to enable the apparatus to be operated selectively, i.e. with or without balance of the washing medium.
  • This invention relates to an improved process for manufacturing electrical apparatus such as transformers and reactors consisting of coil windings mounted within oil-filled casings and to a novel apparatus by which the process can be practiced.
  • the primary object of the invention is to provide an improved process and related apparatus by means of which one is enabled to manufacture in a particularly economic manner and using production cycle techniques with substantial savings in assembly work and time, casing enclosed high-voltage transformers and reactors and with particular emphasis on the production of high quality, paper-insulated windings for such apparatus which is achieved at a much lower production time than has been heretofore possible, and especially with respect to furnace time necessary for drying of the windings to remove moisture.
  • the primary objective of the present invention is not only to avoid the deficiencies of the above-described manufacturing process but also to establish an improved process which requires fewer steps in the manufacture of the windings, including their assembly with the magnetic structure thereby to complete the active component of the apparatus such as a super-voltage transformer or compensation reactor and the insulation on the winding will be maintained free. from air, gases,
  • paper is the most common material used for insulating the conductors from which the windings for the apparatus are formed.
  • sealing agents can be used to seal the insulation on the coil windings against moisture penetration including, fluoro-chloro telomerization products, or paraffines.
  • fluoro-chloro telomerization products or paraffines.
  • paraffines for washing out the sealing agent from the windings, several different mediums have been found to be satisfactory including kerosene, fluorinated organic compounds such as a carbon fluoride, chlorocarbon fluoride, fluorinated amines or ethers having the proper boiling points.
  • an oxidation inhibitor can be admixed with the sealing agent as a protection against oxidation, and in the case where paraffin is used as a sealing agent, the oxidation inhibitor admixed with it can be either ditertiarybutyl-p-cresol (DBPC) or B phenylnaphthylamine. Other oxidation inhibitors can be utilized.
  • DBPC ditertiarybutyl-p-cresol
  • B phenylnaphthylamine B phenylnaphthylamine.
  • Other oxidation inhibitors can be utilized.
  • a novel apparatus For performing the improved process in a particu larly advantageous manner, a novel apparatus has been developed.
  • This includes a combined boiler and still for vaporizing the washing agent which is conducted in vapor form from one outlet thereof by way of a conduit and shut-off valve to an inlet at theupper endof the evacuated casing containing the active component (windings and magnetic structure).
  • the vaporized washing agent washes out the sealing medium from the windings, and the slurry of washing agent and sealing medium is pumped off from an outlet at the bottom of the casing through a conduit including a shut-off valve and a pump, the slurry then being passed through a filter and from the latter to a combined storage tank and still.
  • the slurry is then fed back from the latter into the combined boiler and still through a conduit including another pump where the washing agent and sealing medium are separated, the washing agent then being revaporized and the sealing medium being drawn off for re-use.
  • the vacuum within the casing is produced by a vacuum pump connected to an inlet to the casing at the upper end thereof through conduit means including a shut-off valve at the casing side and a cooling trap intermediate the shut-off valve and vacuum pump. Moisture within the casing and drawn off through the conduit connected to the vacuum pump is separated out in the cooling trap and this liquid is delivered through a conduit containing a shut-off valve to the conduit which carries off the slurry of the washing agent and sealing medium from the casing. The liquid moisture i.e. water, is removed from the combined storage tankstill by a drain pipe.
  • a second outlet from the boiler-still delivers some of the washing agent in vapor form through conduit means including a shut-off valve, the valve being followed by a condenser which liquifies the washing agent for delivery to a storage tank which is maintained under vacuum by another vacuum pump, and this storage tank is connected by way of an equalizing conduit to the combined storage tank and still for the slurry of washing agent and sealing medium.
  • the function of the storage tank for the liquidified washing agent is to enable one to achieve a balance" for the agent, if desired.
  • the apparatus can be operated with, or without balance of the washing agent, this being controlled by means of the shut-off valves provided at the two outlets from the boiler-still.
  • This apparatus which can, of course, be modified in certain respects will ensure continuous handling of insulated windings of the type described, even in the case where large compact banks of coils are involved, thus guaranteeing that the redried winding insulation will possess the same impregnation capacity for absorbing the impregnating oil or other dielectric medium in the same manner as would a new and dry winding which is free from inclusions of gases and foreign matter.
  • the improved process in accordance with the invention and especially in conjunction with the apparatus developed for its practice is particularly advantageous and applicable in connection with the manufacture of high and super'high voltage windings insulated with paper, and particularly for transformer and reactor coils of large size, at substantial savings in labor and time, and which so far as quality is concerned are at least equal to thatachieved by other processesof treatment heretofore known.
  • the paper-insulated conductor bars which are to form the windings are bundled and preferably ovendried under a vacuum' at a temperature of approximately 1 10C and simultaneously pressed, for example, at a pressure of 30 kg/cm to achieve their final, stablizied size. While still in their heated state they are the impregnated with a moisture-proof sealing agent e.g. paraffin heated to C by immersion. This immersion can take place in the heating oven by dipping the conductor bars in a vessel containing the liquified paraffin and which is located within the oven.
  • a moisture-proof sealing agent e.g. paraffin heated to C by immersion. This immersion can take place in the heating oven by dipping the conductor bars in a vessel containing the liquified paraffin and which is located within the oven.
  • the sealed conductors are subjected for approximately 40 hours to treatment under vacuum with the vaporized washing agent e.g. kerosene at llOto C whereupon after stopping the supply of kerosene vapor, the liquid kerosene present within the insulation is vaporized by additional evacuation.
  • the vaporized washing agent e.g. kerosene at llOto C
  • paper insulation treated in the above-described manner is capable of absorbing the impregnating medium, i.e. insulating oil, in the same manner as untreated, i.e. a completely fresh and dry paper insulation, a fact proved by measurement of the capillary rise of insulating oil within the paper tape unwrapped from the conductor, the tape being placed in a vertical position and with the lower end dipped into the insulating oil.
  • the impregnating medium i.e. insulating oil
  • the paper insulation canabsorb paraffin in quantities up to 70 percent of its own weight, it becomes feasible, by a step in the process, to wash, melt or dissolve this paraffin from the insulation inan economic manner so that the paraffin is recovered and becomes re-usable.
  • the mixture of washing agent and sealing medium e.g.
  • kerosene and paraffin bleeding off the winding in the casing is returned to the boiler, serving also as a still, the kerosene being distilled off the paraffin into the storage tank, and the paraffin settling in the boiler being drawn off in its hot and still liquid state and passed through a filter and r'e-used to seal other windings to be treated in accordance with the process of the invention. Cooling of the kerosene, which occurs during this operation, will not cause any clogging of the conduit system employed for conveying the various mediums so long as the kerosene-paraffin slurry does not contain more than 40 percent paraffin.
  • the paraffin retains a kerosene residue of no more than to percent, its properties which are significant for the technological processes, for example, adhesion, will for all practical purposes not be effected when it is'in a solidified state at room temperature. Above all, the windings treated with the paraffin will retain their full capacity of being impregnated with insulating oils, after the paraffin has been removed.
  • the kerosene is very stable, so far as insulating oil is concerned due to its chemical structure, and the oil is not therefore adversely affected by the kerosene. Also, since oxidation inhibitors can be admixed with the paraffin, it becomes possible to prevent formation of organic acids, or acid products, which may occur in particular, at the surface of the oil.
  • Theinvention is advantageous in particular due to the fact that the time required for treatment of the windings or compact banks of windings can be reduced by approximately 30 percent.
  • the sealing technique prevents, primarily repetitious wetting of the winding or of the winding insula-- tion so that it becomes possible to dispense with many of the intermediate steps required by previously known or standard processes, namely, repeated oven treatment of the windings, repeated tightening by the pressing components, and spacing of the windings by means of washers, to overcome shrinkage caused by dring of he Pa ,iy l eaths yire ev n time, n the case of largesized transformers, lasts up to 14 days, representing a highly work-intensive treatment of the windings, the improved process in accordance with the present invention will be greatly advantageous because the winding units manufactured thereby will become stabilized at the time when theyare first dried, with the result that up to the time of the final drying operation, all intermediate heat treatment steps heretofore required in connection with other processes, and including also the re-spacing steps and interruptions of the drying operations will have been omitted. 1 The result is therefore considered
  • FIG. 1 is a diagrammatic representation of the sequential steps involved in a known process for the manufacture of insulated winding components in comparison with the much fewer steps required in the practice of the improved process in accordance with the present invention
  • FIGS. 2a and 2b are elevation and plan views respectively of a known arrangement for affecting stabilization of a winding
  • FIG. 3 is a diagrammatic illustration of an apparatus by which the process in accordance with the present invention is performed
  • FIG. 4 illustrates a bundle of paper insulated electrical conductor bars for which the process in accordance with the invention may be practiced.
  • FIG. 5 illustrates a portion of a transformer structure with its high and low voltage paraffin-sealed windings in final assembled form on the related part of the core and yoke components of the magnetic supporting structure and as it would be installed in its permanent casing and treated in accordancev with the process of the invention by the apparatus depicted in FIG. 3.
  • step 1 the initial oven drying and pressing of the paper insulated conductor is carried out.
  • step 2 indicates temporary storage of the initially dried and pressed winding, i.e. in a storage room at ambient humidity until further needed.
  • step 3 shrink treatment of the winding in an oven takes place by means of which sufficient contraction takes place in order to permit the winding to be assembled with the core and yoke components of the magnetic structure.
  • step 4 indicates final assembly of the shrunkwinding with its core and yoke structure, this likewise taking place in a workroom at ambient humidity.
  • Step 5 indicates rough drying of the final assembly of windings and magnetic structure in an oven.
  • Re-spacing of the windings after rough drying is carried out in step 6 also under ambient humidity conditions.
  • Thorough drying of the re-spaced windings is carried out in an oven in step 7.
  • Installation of the finally dried assembly of re-spaced windings and magnetic structure in the casing is indicated at 8, and in step 9 of the known procedure, re-drying of the encased winding'and magnetic structure and impregnation of the winding with insulating oil takes place.
  • step 1' initial drying, spacing and stabilization of the insulated windings by application of the sealing medium thereto takes place.
  • step 2 which corresponds with step 4 of the prior art shown at the left, involves assembly of the stabilized windings with their core and yoke structureand which is done in a workroom under ambient humidity conditions.
  • step 3' which corresponds somewhat with step 8 of the known procedure, the assembly of windings and magnetic structure in the permanent casing takes place.
  • step 8 which corresponds somewhat with step 8 of the known procedure, the assembly of windings and magnetic structure in the permanent casing takes place.
  • treatment of the assembled winding and magnetic structure with the washing agent e.g. kerosene
  • step 4' which corresponds somewhat to step 9 of the known procedure, the assembly of winding and magnetic structure, now also dired by the hot washing agent is then impregnated with insulating oil.
  • FIG. 2 illustrates a known arrangement for mounting prefabricated paper insulated windings for storage prior to their assembly on their magnetic structure.
  • the winding 1 is mounted between a lower supporting ring 2 and an upper supporting ring 3.
  • the winding and supporting rings are then pressed together by means of a clamping arrangement including lower and upper pres sure plates 5,6 and a plurality of tension rods provided with compression springs 8 and tightening nuts 9.
  • Preferably woodenv spacer blocks 7 are inserted between the upper end of winding 1 and the upper pressure plate 6.
  • the winding mountingstructure as depicted in FIG. 2 is utilized in connection with the manufacture of medium and also large sized windings which are stabilized in the clamped and dry condition by application of a sealing medium, e.g.
  • varnishes especially on a plastic base, and this is done preferably by a soaking or dipping operation.
  • a soaking or dipping operation cannot be utilized for windings which will be subjected to high and super high voltages since the sealing medium, i.e. the varnish utilized to protect the winding against ambient humidity will remain permanently in the insulation and hence will not permit extremely high voltage stresses in the winding for the reasons hereinbefore explained.
  • the insulated windings can be mounted in essentially the same manner as depicted in FIG. 2 and pressed to their final dimensions, after which they are placed in an oven, and perhaps under a vacuum, and impregnated with the sealing medium, e.g. paraffin which is in a hot liquid state.
  • the insulated windings thus become sealed against absorption of moisture from the ambient air and thus are no longer subjected to any changes in dimension; i.e. the windings become completely stabilized.
  • a combined boiler and still 1 serves for vaporizing the washing agent e.g. kerosene which is conducted in vapor form. from one outlet thereof by way of a conduit and shut-off valve 2 to an inlet connection 3 at the upper end of the evacuated casing 4' containing the assembled active component (windings and magnetic structure).
  • the vaporized washing agent washes out the sealing medium e.g.
  • the vacuum within the casing 4 is produced by a vacuum pump 7 connected to an inlet, to the casing at the upper end thereof through conduit means including a shut-off valve 8 and a cooling trap 9 intermediate the shut-off valve 8 and vacuum pump 7. Moisture within the casing and drawn off through the conduit connected to the vacuum pump is fseparated out in. the cooling trap 9 and this liquid is delivered through a conduit containing a shut-off valve 10 to the conduit which carries off the slurry of the washing agent and sealing medium from the casing 4. The liquid moisture i.e. water, is removed from the combined storage tankstill 12 by a drain pipe 13.
  • a second outlet from the boiler-still l delivers some of the washing agent in vapor form through conduit means including a shut-off valve 16, the valve being followed by a condenser 17 which liquifies the washing agent for delivery to a storage tank 18 which is maintained under vacuum by another vacuum pump 19, and this storage tank is connected by way of an equalizing conduit 20 to the combined storage tank and still 12 for the slurry of washing medium and sealing agent.
  • the function of the storage tank 18 for theliquified washing medium is to enable one to achieve a balance for the medium, if desired.
  • the apparatus can be operated with, or without balance of the washing medium, this being controlled by means of the shut-off valves 2,16 provided at the two outlets from the boiler-still 1.
  • This apparatus which can, of course, be modified in certain respects will ensure continuous handling of insulated windings of the type described. Moreover, and what is also important, the apparatus assures recovery of the sealing agent, e.g. paraffin having a quality which makes it re-usable for sealing other windings to be installed in other casings after the one being processed has been completed.
  • the vacuum pump 7 After the supply of vaporized washing medium, e.g. kerosene to the casing 4 has been cut off, e.g. after a 40 hourtreatment under vacuum with vaporized kerosene at a temperature of from 1 l0to C, the vacuum pump 7 is contained in operation to assure removal of all liquid kerosene within the winding insulation and casing.
  • the hot vapor also serves as a heat transfer agent to heat up and effect final drying of the windings.
  • the casing 4 is now disconnected from the apparatus, followed by impregnation of the windings with insulating oil with which the casing is filled.
  • FIG. 4 which is a cross-sectional view, depicts a bundle of nine conductor bars having a rectangular configuration which can be treated in accordance with the process of the invention.
  • the eight outer conductor bars are denoted by numeral 1 and the inside conductor bar, surrounded by the outer bars, is denoted by numeral 2.
  • the individual copper conductor bars are insulated by winding the same with paper tape, the paper insulation 3 consisting, for example, of 24 layers of paper, each with a thickness of 0.05 'mm. and wound onto the conductor bar in helically manner such as to establish an overlap factor of one-third.
  • FIG. 1 is a cross-sectional view
  • FIG. illustrates one portion of a high-power transformer structure which can be manufactured in a particularly advantageous manner when the process and apparatus of the invention are utilized.
  • the upper yoke of the magnetic structure is designated by numeral 1, the lower yoke by 2, the core column by 3, the yoke lamination by 4 and the lower yoke lamination by 5.
  • Upper and lower rings 6 support all of the windings, the supporting base is shown at 7, the upper and lower rings supporting the inner winding at 8, the outer winding by 1 l, supporting parts for the outer winding by 10, the inner winding by 12, the main insulation between the inner and outer windings at 9, horizontally extending oil ducts at 13, vertically extending oil duct at 14, the foot at 15, and the components for fine adjustment between the upper yoke laminations 4 and the upper support ring 6 being indicated at 16.
  • the active part of the transformer as depicted, for example, in part in FIG. 5 would be enclosed within evacuated casing 4', the windings l1 and 12 having previously been stabilized by sealing with the selected sealing agent, e.g. paraffin, so that the paraffin can then be washed out by the kerosene vapor.
  • the selected sealing agent e.g. paraffin
  • Stabilization of the windings by sealing with the sealing agent takes place before the windings are assembled into banks of coils on the magnetic structure. That is, the individual windings may be pre-fabricated at various times, especially if they are mass-produced, and sealed with the sealing agent, and thus can then be assembled without regard to the humidity factor of the ambient air in which the assembly takes place.
  • the newprocess discloses a relatively simple and economic method which solves not only the problem of a temporary seal, held to be incapable of being solved, but also the other above discussed problems, with all advantages as offered by the process and resulting in a product of high quality.
  • This product of a multi-step, time-oriented manufacturing process which can be produced, without being affected, under all humidity conditions which may arise after the drying operation of the prefabrication process, is distinguished by its freedom from impairment by humidity, especially so far as the paper insulation and the windings are concerned, with the result that the characteristics of the windings, stabilized in this manner, are solely determined by the properties as conditioned by the materials used and the production designs desired, and that these windings no longer are subject to uncontrolled influences which heretofore could not be eliminated by the protracted and costly production methods, but have now become feasible due to the fast and compact method of construction as proposed by the invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Insulating Of Coils (AREA)
US00250060A 1971-05-19 1972-05-03 Process of for manufacturing electrical apparatus such as casing-enclosed transformers and reactors Expired - Lifetime US3792528A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH735571A CH532307A (de) 1971-05-19 1971-05-19 Verfahren und Einrichtung zur Herstellung von Aktivteilen für Transformatoren oder Drosseln mit elektrischen Wicklungen mit bandförmigem Isoliermaterial, sowie dessen Anwendung auf Hoch- und Höchstspannungs-Transformatoren oder Drosselspulen

Publications (1)

Publication Number Publication Date
US3792528A true US3792528A (en) 1974-02-19

Family

ID=4323834

Family Applications (1)

Application Number Title Priority Date Filing Date
US00250060A Expired - Lifetime US3792528A (en) 1971-05-19 1972-05-03 Process of for manufacturing electrical apparatus such as casing-enclosed transformers and reactors

Country Status (8)

Country Link
US (1) US3792528A (de)
AT (1) AT318068B (de)
CA (1) CA981887A (de)
CH (1) CH532307A (de)
DE (1) DE2128627A1 (de)
FR (1) FR2137996A1 (de)
IT (1) IT955541B (de)
SE (1) SE387469B (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4261097A (en) * 1978-08-25 1981-04-14 Siemens Aktiengesellschaft Method for insulating superconductors in a magnet winding
US20100064541A1 (en) * 2008-09-17 2010-03-18 Slack Howard C Method for reconditioning fcr apg-68 tactical radar units
US8082681B2 (en) 2008-10-22 2011-12-27 Slack Associates, Inc. Method for improving or reconditioning FCR APG-68 tactical radar units
US20120268227A1 (en) * 2009-09-24 2012-10-25 Jeremy Howes Embedded cooling of wound electrical components
EP2530686A1 (de) * 2011-06-01 2012-12-05 ABB Research Ltd. Pressung von Transformatorwicklungen während aktiver Teiletrocknung
WO2013044510A1 (en) * 2011-09-30 2013-04-04 Siemens Aktiengesellschaft Method of assembling electric transformer
US8505212B2 (en) 2008-09-17 2013-08-13 Slack Associates, Inc. Method for reconditioning or processing a FCR APG-68 tactical radar unit
US8701307B2 (en) 2008-09-17 2014-04-22 Howard C. Slack Method for cleaning and reconditioning FCR APG-68 tactical radar units

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH633633A5 (en) * 1978-11-23 1982-12-15 Micafil Ag Method of drying articles to be dried by means of a vapour flow of an easily volatile liquid and drying arrangement for implementing the method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2168154A (en) * 1938-03-16 1939-08-01 Gen Electric Transformer
US2656290A (en) * 1948-10-28 1953-10-20 Westinghouse Electric Corp Processes for producing electrical coils insulated with mica and synthetic resins and the products thereof
US3138773A (en) * 1959-12-01 1964-06-23 Gen Electric Electrical coils with permeable resin bonding permitting penetration of dielectric liquid therethrough
US3233311A (en) * 1961-06-05 1966-02-08 Gen Electric Method of making encapsulated coils
US3587168A (en) * 1968-10-28 1971-06-28 Westinghouse Canada Ltd Method of making insulated electrical apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2168154A (en) * 1938-03-16 1939-08-01 Gen Electric Transformer
US2656290A (en) * 1948-10-28 1953-10-20 Westinghouse Electric Corp Processes for producing electrical coils insulated with mica and synthetic resins and the products thereof
US3138773A (en) * 1959-12-01 1964-06-23 Gen Electric Electrical coils with permeable resin bonding permitting penetration of dielectric liquid therethrough
US3233311A (en) * 1961-06-05 1966-02-08 Gen Electric Method of making encapsulated coils
US3587168A (en) * 1968-10-28 1971-06-28 Westinghouse Canada Ltd Method of making insulated electrical apparatus

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4261097A (en) * 1978-08-25 1981-04-14 Siemens Aktiengesellschaft Method for insulating superconductors in a magnet winding
US8505212B2 (en) 2008-09-17 2013-08-13 Slack Associates, Inc. Method for reconditioning or processing a FCR APG-68 tactical radar unit
US20100064541A1 (en) * 2008-09-17 2010-03-18 Slack Howard C Method for reconditioning fcr apg-68 tactical radar units
US8056256B2 (en) 2008-09-17 2011-11-15 Slack Associates, Inc. Method for reconditioning FCR APG-68 tactical radar units
US8701307B2 (en) 2008-09-17 2014-04-22 Howard C. Slack Method for cleaning and reconditioning FCR APG-68 tactical radar units
US8082681B2 (en) 2008-10-22 2011-12-27 Slack Associates, Inc. Method for improving or reconditioning FCR APG-68 tactical radar units
US20120268227A1 (en) * 2009-09-24 2012-10-25 Jeremy Howes Embedded cooling of wound electrical components
WO2012163872A1 (en) * 2011-06-01 2012-12-06 Abb Research Ltd Pressing of transformer windings during active part drying
CN103733281A (zh) * 2011-06-01 2014-04-16 Abb研究有限公司 在可动部分干燥过程中变压器绕组的按压
EP2530686A1 (de) * 2011-06-01 2012-12-05 ABB Research Ltd. Pressung von Transformatorwicklungen während aktiver Teiletrocknung
WO2013044510A1 (en) * 2011-09-30 2013-04-04 Siemens Aktiengesellschaft Method of assembling electric transformer
CN103843085A (zh) * 2011-09-30 2014-06-04 西门子公司 装配电变压器的方法
CN103843085B (zh) * 2011-09-30 2016-06-08 西门子公司 装配电变压器的方法

Also Published As

Publication number Publication date
FR2137996A1 (de) 1972-12-29
DE2128627A1 (de) 1972-11-30
IT955541B (it) 1973-09-29
CA981887A (en) 1976-01-20
CH532307A (de) 1972-12-31
SE387469B (sv) 1976-09-06
AT318068B (de) 1974-09-25

Similar Documents

Publication Publication Date Title
US3792528A (en) Process of for manufacturing electrical apparatus such as casing-enclosed transformers and reactors
US3308414A (en) Porous-refractory encapsulant for cous and coil encapsulated therewith
US2857626A (en) Methods of encapsulating articles
US2922734A (en) Fabrication of electrical windings
US1818976A (en) Method of impregnating coils
US4496926A (en) Molded coil structure
US4751488A (en) High voltage capability electrical coils insulated with materials containing SF6 gas
US2269185A (en) Method of forming coil insulation
US1848344A (en) Method of impregnating electrical-conductor insulations
US2718709A (en) Process for drying electrical equipment disposed in a sealed casing
US2456219A (en) Coated inductive device
US3042743A (en) Coil for electrical rotating machine
US3274320A (en) Method of encapsulating transformer
US2469099A (en) Electric windings and leads therefor
US3119085A (en) Welding transformer
Russek Drying and impregnation of paper-insulated power cables
US3117900A (en) Insulating electrical conductors
US1653805A (en) Method of removing enamel from electrical conductors
KR870001454B1 (ko) 전기 기기의 절연처리 방법
US1872358A (en) Insulating material
JPS62299010A (ja) 樹脂成形コイルの製造方法
JPS6343989B2 (de)
RU2037897C1 (ru) Способ изготовления катушек с торцевым охлаждением для электрофизических установок
US3250837A (en) Method of molding insulated coils by application of differential fluid pressure
SU1697203A1 (ru) Способ изготовлени кор электрической машины