CA2351440A1 - Corona shielding arrangement and method for the production thereof - Google Patents
Corona shielding arrangement and method for the production thereof Download PDFInfo
- Publication number
- CA2351440A1 CA2351440A1 CA002351440A CA2351440A CA2351440A1 CA 2351440 A1 CA2351440 A1 CA 2351440A1 CA 002351440 A CA002351440 A CA 002351440A CA 2351440 A CA2351440 A CA 2351440A CA 2351440 A1 CA2351440 A1 CA 2351440A1
- Authority
- CA
- Canada
- Prior art keywords
- corona shielding
- slot
- conducting
- winding
- shielding material
- 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.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/32—Windings characterised by the shape, form or construction of the insulation
- H02K3/40—Windings characterised by the shape, form or construction of the insulation for high voltage, e.g. affording protection against corona discharges
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
- H02K15/10—Applying solid insulation to windings, stators or rotors
- H02K15/105—Applying solid insulation to windings, stators or rotors to the windings
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Insulation, Fastening Of Motor, Generator Windings (AREA)
Abstract
The invention relates to a corona shielding arrangement for the stator winding of high voltage rotary machines with round-wire winding in combination with slot portion insulation. Also disclosed is a method for the production of said corona shielding arrangement. The object of the invention is to create an overhang corona shielding and provide a method for the production of said shielding for a stator winding which safely controls electrical stresses, especially those arising at the end of a slot during testing with high alternating voltages and surge voltages and when a switching operation is carried out. Contact between the slot portion shielding and overhang corona shielding is improved and higher partial discharge inception voltages are created. According to the invention, the corona shielding arrangement is structured in such a way that the conductor and semi-conductor shielding materials are disposed both outside and inside the laminated stator core. The semiconductor material for the overhang corona shielding is composed of a flat semiconductor corona shielding material cut into strips on both sides at the level of the slot, and optionally, also at the base of the slot on the lining thereof. The point of contact between the conductor and semiconductor corona shielding material is located inside the laminated stator core. According to the inventive method, the semiconductor corona shielding materials which are to be arranged on the conductor corona shielding material are only partially glued. The winding is introduced gradually into the slots via the opening thereof. The end winding is subsequently integrated, whereby the lining of the slot projecting therefrom is also insulated up to the laminated stator core and the semiconductor corona shielding material must be kept at a distance from the lining of the slot. The semiconductor corona shielding material is then arranged on the insulation of the end winding and secured by means of an adhesive strip or cover band which is placed over the insulation of the end winding.
Description
Corona shielding arrangement and techniques to fabricate it This invention relates to a corona shielding arrangement for the stator winding of rotating high-voltage machines with round-wire winding combined with a slot portion insulation consisting of a slot liner with a conducting slot-portion corona shielding, a semi-conducting overhang corona shielding, and a technique to fabricate the corona shielding arrangement.
Overhang corona shielding arrangements in high-voltage machines with former windings made of rectangular wire and sleeve insulation with semi-conducting corona shielding to varnish or semi-conducting corona shielding tape to improve the voltage distribution at the slot end are known in a large variety of designs.
DE 30 45 462 describes a solution wherein a shielding base material, consisting of semi-conducting material, is wound onto the ground insulation as overhang corona shielding and 15 subsequently impregnated.
DE 42 18 928 comprises an overhang corona shielding arrangement wherein a semi-conducting corona shielding tape is applied on top of the ground insulation with the overlapping decreasing towards the end of the bar.
In DE 196 34 578 an overhang corona shielding arrangement is described wherein the voltage distribution is improved by using grading rings (equipotential rings) on the insulation in the area of the slot end.
The above referenced arrangements or techniques have several disadvantages:
In order to obtain the specified overlapping and to satisfy the technological specifications, the semi-conducting corona shielding tape must be applied very carefully by wrapping.
Folds or gaps in the wrapping are inadmissible. However, it is difficult to meet this 3o requirement, particularly when a tape of greater length is applied.
Additional impregnation to obtain the desired overhang corona shielding effect requires extra technological work.
This is also true of the proposed grading arrangements.
The known coatings with semi-conducting corona shielding varnishes which are provided to obtain the desired overhang corona shielding cannot be applied at all in the case of a slot portion insulation which consists of panel-type insulating material because they must be applied by spreading or spraying prior to impregnating them with liquid insulating medium at the slot end, and in doing so they penetrate into the ground insulation in the overlapping zone of the panel-type insulating material, usually in the area of the slot opening, where they unacceptably shorten the creepage path between winding wire and laminated core.
When using semi-conducting corona shielding tapes to provide the overhang corona shielding, any contacting of the tapes with the conductive corona shielding of the slot portion is problematic because at high voltages poor contacting results in partial discharges, which again, further worsens the contact making so that finally the overhang corona shielding becomes ineffective. In all common arrangements used to date, the point of contact is located outside the laminated stator core.
It is an object of this invention to provide a corona shielding arrangement and a technique to 5o fabricate it relating to the stator winding of rotating high-voltage machines with round-wire winding and slot lining, thus providing an overhang corona shielding which safely controls all electric stresses occurring at the slot end, primarily during power-frequency and impulse voltage testing as well as during switching operations during service, and which provides good contact making between slot portion and overhang corona shielding thus causing higher partial-discharge inception voltages, and which reduces material consumption and time required for fabricating the overhang corona shielding of the high-voltage winding.
In accordance with the present invention, the object is achieved by the characteristic features of Claim l and Claim 2. According to this invention the corona shielding 1 o arrangement for the stator winding of rotating high-voltage machines with round-wire winding, slot lining and corona shielding material is fabricated so that the slot lining on the side facing the laminated core consists of conducting and semi-conducting corona shielding materials arranged both outside the laminated stator core and inside the laminated stator core with the semi-conducting material used for the overhang corona shielding consisting of 15 monoplane semi-conducting corona shielding material, cut into strips, and arranged on either side at slot level and, if required, .also on the bottom of the slot on the slot lining. The point of contact between conducting and semi-conducting corona shielding materials is located within the laminated stator core. Optionally, the slot lining may consist of one or several layers.
According to the suggested technique the semi-conducting corona shielding materials to be arranged at the conducting corona-shielding material are glued on only partially. The semi-conducting corona shielding materials may also be inserted in the slot ends during or after arrangement of the slot lining. Subsequently the winding is drop-fed into the slots through the slot opening and the slot closed by folding the slot lining and inserting the slot closing strip. Then the end winding is wrapped whereby the slot lining protruding from the slot is also insulated up to the laminated stator core. In doing so the semi-conducting corona shielding material must be kept away from the slot lining. Upon completion of this operation, the semi-conducting corona shielding material is applied to the end winding 3o insulation and fastened with adhesive tape or cover tape which is placed on the end winding insulation.
In a preferred arrangement the conducting corona shielding material is glued onto the slot lining covering the surface either partially and/or fully. Preferably, the conducting corona shielding material may be of the same length as the laminated stator core.
According to this invention, an overhang corona shielding does not require complete wrapping of the round-wire windings in the zone of the end winding with overhang corona shielding tape. Favourable voltage distribution is obtained throughout the entire insulation 4o in the area of the slot end. Partial discharges are reliably limited and it is now possible to satisfy the typical testing conditions for high-voltage machines without causing any damage to the winding insulation. Due to the strip-type design of the overhang corona shielding, fabricated according to the present invention, the invention guarantees effective potential grading for round-wire windings with slot lining.
In the following the invention will be explained in greater detail in a preferred embodiment describing a corona shielding arrangement for the stator winding of rotating high-voltage machines wherein the stator winding which is executed as a blank round-wire winding is inserted in slots of a laminated stator core with straight slot bottom.
According to the 5o present invention, strips of semi-conducting corona shielding material are arranged on the two sides of the slot and on the slot bottom. These three strips consisting of semi-conducting corona shielding material are arranged on top of the conducting corona shielding material of the slot so that they are contacting each other within the laminated stator core. The said conducting corona shielding material is arranged on the slot lining. It may either be inserted only or alternatively glued to the said slot lining. Subsequently, the slot lining is inserted in the stator slot together with the corona shielding fabricated according to this invention,.
Depending on electrical stresses to be expected, the slot lining may consist of one or several layers.
1o Next the winding is fed-in and the slot closed. Now the three strips of the semi-conducting corona shielding material must be kept away from the slot lining. Then the end winding is wrapped with insulating tapes wherein the slot lining protruding from the slot is being insulated up to the laminated stator core. Following this operation, the three strips of the said semi-conducting corona shielding material are placed onto the insulation of the end 15 winding and fastened with adhesive tape or cover tape which is wrapped on top of said end winding insulation.
When the slot bottom is rounded, only two strips of the semi-conducting corona shielding material are arranged on top of the conducting corona shielding material of the slot. The 2o width of said semi-conducting corona shielding material shall be preferably equivalent to the height of the straight slot slope. Here again, the material should preferably be glued onto the conducting corona shielding material only in some points to ensure contacting.
Subsequently, as is known, the stator winding is impregnated with resin using a common impregnating procedure.
_L~-Summary Corona shielding arrangement and techniques to fabricate it The invention relates to a corona shielding arrangement for the stator winding of rotating high-voltage machines with round-wire winding combined with a slot portion insulation and a technique to fabricate the corona shielding arrangement.
It is an object of this invention to provide an overhang corona shielding and a technique for its fabrication relating to a stator winding which safely controls the electric stresses to occurring at the slot end, primarily during power-frequency and impulse voltage testing as well as during switching operations during service. It is a further object of this invention to improve the contact between slot portion and overhang corona shielding and to allow higher partial-discharge inception voltages.
According to the present invention the corona shielding arrangement for the stator winding t 5 is designed so that conducting and semi-conducting corona shielding materials are arranged both outside the laminated stator core and inside the laminated stator core wherein the semi-conducting material used for the overhang corona shielding consists of monoplane semi-conducting corona shielding material, cut into strips, and arranged on either side at slot level and, if required, also on the bottom of the slot on top of the slot lining.
The point of contact 2o between conducting and semi-conducting corona shielding material is located within the laminated stator core.
According to the present technique the semi-conducting corona shielding materials to be arranged on the conducting corona-shielding material are glued on only partially.
Subsequently the winding is drop-fed into the slots through the slot opening.
They the end 25 winding is wrapped wherein the slot lining protruding from the slot is also insulated up to the laminated stator core. In doing so the semi-conducting corona shielding material must be kept away from the slot lining. Upon completion of this operation, the semi-conducting corona shielding material is applied to the end winding insulation and fastened with adhesive tape or cover tape which is applied on top of the end winding insulation.
Overhang corona shielding arrangements in high-voltage machines with former windings made of rectangular wire and sleeve insulation with semi-conducting corona shielding to varnish or semi-conducting corona shielding tape to improve the voltage distribution at the slot end are known in a large variety of designs.
DE 30 45 462 describes a solution wherein a shielding base material, consisting of semi-conducting material, is wound onto the ground insulation as overhang corona shielding and 15 subsequently impregnated.
DE 42 18 928 comprises an overhang corona shielding arrangement wherein a semi-conducting corona shielding tape is applied on top of the ground insulation with the overlapping decreasing towards the end of the bar.
In DE 196 34 578 an overhang corona shielding arrangement is described wherein the voltage distribution is improved by using grading rings (equipotential rings) on the insulation in the area of the slot end.
The above referenced arrangements or techniques have several disadvantages:
In order to obtain the specified overlapping and to satisfy the technological specifications, the semi-conducting corona shielding tape must be applied very carefully by wrapping.
Folds or gaps in the wrapping are inadmissible. However, it is difficult to meet this 3o requirement, particularly when a tape of greater length is applied.
Additional impregnation to obtain the desired overhang corona shielding effect requires extra technological work.
This is also true of the proposed grading arrangements.
The known coatings with semi-conducting corona shielding varnishes which are provided to obtain the desired overhang corona shielding cannot be applied at all in the case of a slot portion insulation which consists of panel-type insulating material because they must be applied by spreading or spraying prior to impregnating them with liquid insulating medium at the slot end, and in doing so they penetrate into the ground insulation in the overlapping zone of the panel-type insulating material, usually in the area of the slot opening, where they unacceptably shorten the creepage path between winding wire and laminated core.
When using semi-conducting corona shielding tapes to provide the overhang corona shielding, any contacting of the tapes with the conductive corona shielding of the slot portion is problematic because at high voltages poor contacting results in partial discharges, which again, further worsens the contact making so that finally the overhang corona shielding becomes ineffective. In all common arrangements used to date, the point of contact is located outside the laminated stator core.
It is an object of this invention to provide a corona shielding arrangement and a technique to 5o fabricate it relating to the stator winding of rotating high-voltage machines with round-wire winding and slot lining, thus providing an overhang corona shielding which safely controls all electric stresses occurring at the slot end, primarily during power-frequency and impulse voltage testing as well as during switching operations during service, and which provides good contact making between slot portion and overhang corona shielding thus causing higher partial-discharge inception voltages, and which reduces material consumption and time required for fabricating the overhang corona shielding of the high-voltage winding.
In accordance with the present invention, the object is achieved by the characteristic features of Claim l and Claim 2. According to this invention the corona shielding 1 o arrangement for the stator winding of rotating high-voltage machines with round-wire winding, slot lining and corona shielding material is fabricated so that the slot lining on the side facing the laminated core consists of conducting and semi-conducting corona shielding materials arranged both outside the laminated stator core and inside the laminated stator core with the semi-conducting material used for the overhang corona shielding consisting of 15 monoplane semi-conducting corona shielding material, cut into strips, and arranged on either side at slot level and, if required, .also on the bottom of the slot on the slot lining. The point of contact between conducting and semi-conducting corona shielding materials is located within the laminated stator core. Optionally, the slot lining may consist of one or several layers.
According to the suggested technique the semi-conducting corona shielding materials to be arranged at the conducting corona-shielding material are glued on only partially. The semi-conducting corona shielding materials may also be inserted in the slot ends during or after arrangement of the slot lining. Subsequently the winding is drop-fed into the slots through the slot opening and the slot closed by folding the slot lining and inserting the slot closing strip. Then the end winding is wrapped whereby the slot lining protruding from the slot is also insulated up to the laminated stator core. In doing so the semi-conducting corona shielding material must be kept away from the slot lining. Upon completion of this operation, the semi-conducting corona shielding material is applied to the end winding 3o insulation and fastened with adhesive tape or cover tape which is placed on the end winding insulation.
In a preferred arrangement the conducting corona shielding material is glued onto the slot lining covering the surface either partially and/or fully. Preferably, the conducting corona shielding material may be of the same length as the laminated stator core.
According to this invention, an overhang corona shielding does not require complete wrapping of the round-wire windings in the zone of the end winding with overhang corona shielding tape. Favourable voltage distribution is obtained throughout the entire insulation 4o in the area of the slot end. Partial discharges are reliably limited and it is now possible to satisfy the typical testing conditions for high-voltage machines without causing any damage to the winding insulation. Due to the strip-type design of the overhang corona shielding, fabricated according to the present invention, the invention guarantees effective potential grading for round-wire windings with slot lining.
In the following the invention will be explained in greater detail in a preferred embodiment describing a corona shielding arrangement for the stator winding of rotating high-voltage machines wherein the stator winding which is executed as a blank round-wire winding is inserted in slots of a laminated stator core with straight slot bottom.
According to the 5o present invention, strips of semi-conducting corona shielding material are arranged on the two sides of the slot and on the slot bottom. These three strips consisting of semi-conducting corona shielding material are arranged on top of the conducting corona shielding material of the slot so that they are contacting each other within the laminated stator core. The said conducting corona shielding material is arranged on the slot lining. It may either be inserted only or alternatively glued to the said slot lining. Subsequently, the slot lining is inserted in the stator slot together with the corona shielding fabricated according to this invention,.
Depending on electrical stresses to be expected, the slot lining may consist of one or several layers.
1o Next the winding is fed-in and the slot closed. Now the three strips of the semi-conducting corona shielding material must be kept away from the slot lining. Then the end winding is wrapped with insulating tapes wherein the slot lining protruding from the slot is being insulated up to the laminated stator core. Following this operation, the three strips of the said semi-conducting corona shielding material are placed onto the insulation of the end 15 winding and fastened with adhesive tape or cover tape which is wrapped on top of said end winding insulation.
When the slot bottom is rounded, only two strips of the semi-conducting corona shielding material are arranged on top of the conducting corona shielding material of the slot. The 2o width of said semi-conducting corona shielding material shall be preferably equivalent to the height of the straight slot slope. Here again, the material should preferably be glued onto the conducting corona shielding material only in some points to ensure contacting.
Subsequently, as is known, the stator winding is impregnated with resin using a common impregnating procedure.
_L~-Summary Corona shielding arrangement and techniques to fabricate it The invention relates to a corona shielding arrangement for the stator winding of rotating high-voltage machines with round-wire winding combined with a slot portion insulation and a technique to fabricate the corona shielding arrangement.
It is an object of this invention to provide an overhang corona shielding and a technique for its fabrication relating to a stator winding which safely controls the electric stresses to occurring at the slot end, primarily during power-frequency and impulse voltage testing as well as during switching operations during service. It is a further object of this invention to improve the contact between slot portion and overhang corona shielding and to allow higher partial-discharge inception voltages.
According to the present invention the corona shielding arrangement for the stator winding t 5 is designed so that conducting and semi-conducting corona shielding materials are arranged both outside the laminated stator core and inside the laminated stator core wherein the semi-conducting material used for the overhang corona shielding consists of monoplane semi-conducting corona shielding material, cut into strips, and arranged on either side at slot level and, if required, also on the bottom of the slot on top of the slot lining.
The point of contact 2o between conducting and semi-conducting corona shielding material is located within the laminated stator core.
According to the present technique the semi-conducting corona shielding materials to be arranged on the conducting corona-shielding material are glued on only partially.
Subsequently the winding is drop-fed into the slots through the slot opening.
They the end 25 winding is wrapped wherein the slot lining protruding from the slot is also insulated up to the laminated stator core. In doing so the semi-conducting corona shielding material must be kept away from the slot lining. Upon completion of this operation, the semi-conducting corona shielding material is applied to the end winding insulation and fastened with adhesive tape or cover tape which is applied on top of the end winding insulation.
Claims (3)
1. Corona shielding arrangement for the stator winding of rotating high-voltage machines with round-wire winding, slot portion insulation and both conducting and semi-conducting corona shielding material, characterized in that the slot portion insulation is provided with conducting and semi-conducting corona shielding materials both outside and inside the laminated stator core, wherein the point of contact between the conducting and the semi-conducting corona shielding material is located within the stator core and the corona shielding material is applied to a slot lining which consists of one or several layers.
2. Technique to fabricate a corona shielding arrangement according to claim 1, characterized in that - the semi-conducting corona shielding materials to be applied on the conducting corona shielding material inside the laminated stator core for voltage grading are either glued on the slot liner only partially before installing the liner in the slot or are inserted into the slot ends together with the conducting corona shielding material after installing the slot liner, - the winding is drop-fed, - in this process, the semi-conducting corona shielding material is kept away from the slot liner - the end winding is insulated up to the stator core, including the slot liner, which protrudes from the slot;
- the semi-conducting corona shielding material is applied to the end winding insulation after the end winding has been insulated, and in that - the corona shielding material is fastened either by means of an adhesive fleece or by means of the cover tape.
- the semi-conducting corona shielding material is applied to the end winding insulation after the end winding has been insulated, and in that - the corona shielding material is fastened either by means of an adhesive fleece or by means of the cover tape.
3. Corona shielding arrangement for the stator winding of rotating high-voltage machines according to claim 1, characterized in that - the conducting corona shielding material has preferably exactly the length of the laminated stator core.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19944664.4 | 1999-09-17 | ||
| DE1999144664 DE19944664A1 (en) | 1999-09-17 | 1999-09-17 | Glow protection arrangement and method for its production |
| PCT/DE2000/003203 WO2001022557A2 (en) | 1999-09-17 | 2000-09-14 | Corona shielding arrangement and method for the production thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2351440A1 true CA2351440A1 (en) | 2001-03-29 |
Family
ID=7922417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002351440A Abandoned CA2351440A1 (en) | 1999-09-17 | 2000-09-14 | Corona shielding arrangement and method for the production thereof |
Country Status (4)
| Country | Link |
|---|---|
| BR (1) | BR0007157A (en) |
| CA (1) | CA2351440A1 (en) |
| DE (1) | DE19944664A1 (en) |
| WO (1) | WO2001022557A2 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000011131A (en) * | 1996-05-15 | 2000-02-25 | 칼 하인쯔 호르닝어 | Conductor winding arrangement for heavy electric machines |
-
1999
- 1999-09-17 DE DE1999144664 patent/DE19944664A1/en not_active Withdrawn
-
2000
- 2000-09-14 WO PCT/DE2000/003203 patent/WO2001022557A2/en active Application Filing
- 2000-09-14 CA CA002351440A patent/CA2351440A1/en not_active Abandoned
- 2000-09-14 BR BR0007157-9A patent/BR0007157A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| BR0007157A (en) | 2001-09-18 |
| WO2001022557A2 (en) | 2001-03-29 |
| DE19944664A1 (en) | 2001-08-09 |
| WO2001022557A3 (en) | 2002-04-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |