WO1997035327A1 - Electrical apparatus having electrical conductors mounted in electrical insulation - Google Patents
Electrical apparatus having electrical conductors mounted in electrical insulation Download PDFInfo
- Publication number
- WO1997035327A1 WO1997035327A1 PCT/GB1997/000757 GB9700757W WO9735327A1 WO 1997035327 A1 WO1997035327 A1 WO 1997035327A1 GB 9700757 W GB9700757 W GB 9700757W WO 9735327 A1 WO9735327 A1 WO 9735327A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- insulating material
- electrical
- electrically insulating
- rigid
- electrical apparatus
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B17/00—Insulators or insulating bodies characterised by their form
- H01B17/26—Lead-in insulators; Lead-through insulators
- H01B17/30—Sealing
- H01B17/303—Sealing of leads to lead-through insulators
- H01B17/306—Sealing of leads to lead-through insulators by embedding in material other than glass or ceramics
Definitions
- This invention relates to electrical apparatus having rigid electric conductors mounted in electrical insulation and to a method of manufacturing such electrical apparatus.
- the invention relates to high voltage apparatus, such as tapchangers, transformers or switchgear, in which the electrical conductors comprise electrodes, tappings or the like.
- DMC dough moulding compounds
- bulk moulding compounds provide good, relatively cheap electrical insulation for low voltage applications.
- rigid electrical conductors can be held in desired positions while the DMC i ⁇ heated and moulded around the conductors in compression heated dies to produce electrical apparatus in which the electrical conductors are mounted in a moulded, electrically insulating support.
- electrical apparatus incorporating DMC as the electrically insulating material has proved to be unsatisfactory for high voltage applications since the insulation tends to break down when a high voltage potential is applied between the conductors mounted in the insulation.
- An aim of the present invention is to enable the use of mouldable electrically insulating material in high voltage electrical grade apparatus.
- high voltage electrical apparatus comprising an insulating support made of a moulded first electrically insulating material and carrying rigid electrical conductors electrically insulated from each other, is characterised in that each rigid electrical conductor is at least partly surrounded with a homogeneous second electrically insulating material.
- the first electrically insulating material is moulded from a dough moulding compound, e.g. a thermosetting composite moulding material such as a polyester moulding compound or the like.
- the second electrically insulating material comprises an epoxy or polyester material with filler material, e.g silica.
- the second insulating material will be the same insulating material for each rigid electrical conductor but this is not essential. However it is important that the second insulating material should be homogeneous and have no "flow line" faults. Typically it will be formed around the electrical conductors by vacuum pouring. Alternatively, however, it may, for example, be cast over a relatively long period of time to ensure that it sets as a homogeneous mass with no internal voids or fault lines.
- each rigid electrical conductor comprises a sleeve surrounding the conductor and fixed thereto.
- each sleeve is cast, e.g. vacuum or gravity cast, onto its associated electrical conductor.
- a method of manufacturing a high voltage electrical apparatus comprising arranging rigid electrical conductors in an insulating support made of a moulded first electrically insulating material, is characterised in that each rigid electrical conductor is initially at least partly surrounded by a homogeneous screen of second electrically insulating material and thereafter the first electrically insulating material is moulded around the previously insulated electrical conductors.
- the second electrically insulating material is cast, e.g. vacuum or gravity cast, about the rigid electrical conductors.
- the second electrically insulating material may comprise, for each rigid electrical conductor, a pre-formed homogeneous sleeve which is connected, e.g. via screw-threads, in an interference fit or even with adhesive, to its associated electrical conductor.
- the first electrically insulating material preferably comprises a dough moulding compound such as a thermosetting polyester moulding compound, but other mouldable electrically insulating materials may be used.
- Dough moulding compound is moulded in moulds to provide the desired shape of insulating support and these are heated to enable curing of the dough moulding compound. Since the dough moulding compound attains temperatures typically of about 130°C during this curing process, the second electrically insulating material must be able to withstand such temperatures without melting.
- Figure 1 is a schematic sectional view of part of a known high voltage electrical tapchanger
- Figure 2 is a schematic sectional view of part of a high voltage electrical tapchanger made in accordance with the present invention.
- Figure 1 shows two tappings or electrodes 1 and 2 of a known high voltage electrical tapchanger, generally designated by the reference numeral 3, which are securely mounted in an electrically insulating support 4.
- the support 4 has been made of a high grade insulating material, e.g. epoxy resin or the like, for high voltage electrical grade apparatus to ensure that breakdown in the insulating properties of the support does not occur when high voltage potential are applied between the electrodes 1 and 2.
- Figure 2 illustrates how the apparatus shown in Figure 1 can be modified in accordance with the principles of the present invention.
- Figure 2 shows a modified tapchanger 13 having two electrodes 11 and 12 securely mounted in an electrically insulating support 14 moulded from a heat cured, dough moulding compound, such as a thermo-setting composite moulding material.
- a heat cured, dough moulding compound such as a thermo-setting composite moulding material.
- sleeves 16 and l of electrical grade, electrically insulating material e.g. epoxy material or polyester material with filler material such as silica
- the electrically insulating sleeves 16 and 17 are thus securely retained on the electrodes 11 and 12, respectively.
- the electrode/sleeve assemblies 11/16 and 12/17 are then moulded in their correct locations into the support 4. This is achieved by heating the dough moulding compound, which is retained in a compression mould (not shown) , to an elevated temperature of about 130°C and at an elevated pressure, e.g. from 17 to 140 bar, so that the compound flows around the electrode/sleeve assemblies 11/16 and 12/17.
- the dough moulding compound provides a relatively cheap, rigid electrically insulating support 4 for the electrodes 11 and 12.
- flow lines 15 may be created in the support 4 during curing of the dough moulding compound, the presence of the homogeneous insulating sleeves 16 and 17 containing no fault line or internal voids around the electrodes 11 and 12 guarantees a relatively high electrical withstand level.
- the dough moulding compound conveniently comprises a mixture of unsaturated polyester resin or epoxy resin, chopped strands of glass fibre reinforcement, mineral, e.g. silica, fillers, and preferably a shrinkage control additive and a hot press cure additive.
- a suitable polyester moulding compound is available from BIP Chemical Limited under the trade name "Beetle”. Other mouldable compounds can be employed instead.
- the "Beetle” product is supplied fully compounded and ready to mould in a dough (DMC) , often referred to as a bulk moulding compound, and ha ⁇ high strength and rigidity, excellent electrical properties and good dimensional accuracy and stability. Only low pressures, e.g. 17 to 140 bar are required to mould the product.
- the sleeves 16 and 17 have been described as being vacuum or gravity cast around the electrodes 11 and 12, respectively, other means of providing a sleeve/electrode connection may be employed.
- mechanical screw or interference connections may be used or, alternatively, the sleeves may be adhesively bonded to the electrodes.
- Adequate electrical insulation may also be provided if only part of the electrodes (i.e. the part or parts facing an adjacent electrode or electrodes) are surrounded or covered with electrical grade insulating material.
- the sleeves 16 and 17 will generally be made of the same electrical grade insulating material although this is not essential.
- the material of the sleeve must, however, be able to resist without melting the curing temperatures experienced during moulding of the support 14 and must result in a homogeneous sleeve.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9533256A JP2000507030A (en) | 1996-03-19 | 1997-03-19 | Electrical equipment having an electrical conductor mounted in an electrical insulator |
EP97908368A EP0891625A1 (en) | 1996-03-19 | 1997-03-19 | Electrical apparatus having electrical conductors mounted in electrical insulation |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9605723.7 | 1996-03-19 | ||
GB9605723A GB2311418B (en) | 1996-03-19 | 1996-03-19 | Electrical apparatus having electrical conductors mounted in electrical insulation |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997035327A1 true WO1997035327A1 (en) | 1997-09-25 |
Family
ID=10790633
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1997/000757 WO1997035327A1 (en) | 1996-03-19 | 1997-03-19 | Electrical apparatus having electrical conductors mounted in electrical insulation |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0891625A1 (en) |
JP (1) | JP2000507030A (en) |
GB (1) | GB2311418B (en) |
WO (1) | WO1997035327A1 (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1152704A (en) * | 1965-07-22 | 1969-05-21 | Permali Ltd | Improvements in Cast Resin Bushings. |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3388212A (en) * | 1965-07-07 | 1968-06-11 | Gen Electric | Plastic bushing for electrical apparatus and method of making |
CH552883A (en) * | 1972-06-15 | 1974-08-15 | Stamina Ag | GAS-TIGHT, ELECTRICALLY INSULATING PIPE FOR ELECTRIC CONDUCTORS. |
-
1996
- 1996-03-19 GB GB9605723A patent/GB2311418B/en not_active Expired - Fee Related
-
1997
- 1997-03-19 WO PCT/GB1997/000757 patent/WO1997035327A1/en not_active Application Discontinuation
- 1997-03-19 JP JP9533256A patent/JP2000507030A/en active Pending
- 1997-03-19 EP EP97908368A patent/EP0891625A1/en not_active Withdrawn
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1152704A (en) * | 1965-07-22 | 1969-05-21 | Permali Ltd | Improvements in Cast Resin Bushings. |
Also Published As
Publication number | Publication date |
---|---|
GB9605723D0 (en) | 1996-05-22 |
GB2311418A (en) | 1997-09-24 |
JP2000507030A (en) | 2000-06-06 |
GB2311418B (en) | 2000-10-25 |
EP0891625A1 (en) | 1999-01-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0070661B1 (en) | Insulated electromagnetic coil, method and product | |
US20080142485A1 (en) | Method for producing breaker pole parts for low-voltage, medium-voltage and high-voltage switchgear assemblies, and breaker pole part itself | |
US3513253A (en) | Cast condenser bushing having tubular metal coated mesh plates | |
US20100314357A1 (en) | Resin-molded vacuum valve | |
KR920005818B1 (en) | Resin bonded magnet | |
US3737987A (en) | Method of making an insulated armature | |
KR20190064787A (en) | Epoxy resin composition and transformer comprising the same | |
EP0891625A1 (en) | Electrical apparatus having electrical conductors mounted in electrical insulation | |
EP0075471A1 (en) | Electrical bushing and method of manufacture thereof | |
US4681985A (en) | Premolded mechanically prestressed voltage stress control cones for high voltage cables and method of fabricating same | |
JP2000294087A (en) | Resin mold vacuum valve | |
EP0321263A2 (en) | Power cable jointing | |
JP2622053B2 (en) | Manufacturing method of coil for electromagnet | |
US6118078A (en) | Structural element | |
KR940023266A (en) | Potato coil manufacturing method and coil manufactured by this method | |
JP2901289B2 (en) | How to connect the power cable | |
JP3748324B2 (en) | Coil for rotating electrical machine | |
JP2656381B2 (en) | Manufacturing method of coil for electromagnet | |
CA1240461A (en) | Conductor insulating method and apparatus | |
EP0893805B1 (en) | Polymeric insulator for supporting electrical lines and electrical components in general. | |
JPS6247281B2 (en) | ||
JPS5927601Y2 (en) | resin embedded coil | |
JPS58194307A (en) | Resin-molded electromagnetic winding | |
JPH06114855A (en) | Production of injection molded product composed of epoxy resin composition | |
JPS62274579A (en) | Method of forming joint of rubber or plastic power cable |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): JP |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1997908368 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: CA |
|
WWP | Wipo information: published in national office |
Ref document number: 1997908368 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1997908368 Country of ref document: EP |