JPH10295063A - Method for resin-impregnation and hardening of electrical apparatus winding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a resin-impregnating property and electrical characteristics by a method, wherein a coil in which an insulating layer is formed around a conductor is arranged inside a pressure container, the pressure at the inside of the pressure container is decreased and an impregnating resin is injected from the end part of the coil. SOLUTION: A coil 7, for an electrical rotating machine, which is to be impregnated with a resin is arranged in the hollow part of a pressure container 1. In the coil 7, an insulating layer 702 is formed around a conductor 701. Then, a resin introduction pipe 3 is connected to the end part of the coil 7 via a connection part 8. In this state, the pressure at the inside of the pressure container 1 is reduced via a decompression port 10, and at the same time, an impregnating resin is injection from the end part of the coil 7 via the resin introduction pipe 3. In this case, the face of an impregnating resin 5 in a resin storage tank 4 is pressurized by an external gas 6, the impregnating resin 5 which is injected into the end of the coil 7 from the resin introduction pipe 3 is pressurized, and a difference in pressure applied to an insulating layer 702 from the inside of the coil is made large. Thereby, a resin-impregnating property and electrical characteristics can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for impregnating and curing a winding of an electric device used for a large rotating electric machine such as a water turbine generator or a turbine generator.

[0002]

2. Description of the Related Art Conventionally, as a method of impregnating a large coil such as a large rotating electric machine such as a turbine generator or a turbine generator with a resin, first, a predetermined number of composite insulating tapes mainly composed of mica as an insulating material are wound around the coil. In general, a method in which the impregnated resin is rotated and placed in a pressure vessel, and then impregnation under reduced pressure and pressure (VPI) is performed, and the impregnated resin is cured by applying a mold or the like.

[0003] In this method, in the first stage of vacuum impregnation, the degree of vacuum is reduced to about 0.1 Torr, and then resin is gradually injected to fill the coil. And
By further reducing the pressure, the exhaustion of the gas in the coil insulator and the replacement and penetration of the resin are promoted, and the resin impregnation rate is increased.

However, in this method, since the resin is impregnated from outside the coil, it is difficult to completely exhaust the gas in the insulator and replace it with the resin. Therefore, after moderate pressure impregnation, switching to pressurization to crush the residual gas reduces the gas (voids) present in the insulator, and further improves the resin impregnation rate. I have.

However, even in this case, voids in the insulator cannot be completely removed. This is because, when gas is present in the coil insulator, the coil is wrapped in resin, and in small parts of the insulator, the resin is not sufficiently replaced by gas due to the viscosity of the resin, and voids are formed. It is a cause that remains. And if voids remain in the insulator, such as coils used under high voltage,
Partial discharge starting from a void was easily generated, greatly affecting the life of the coil, and the reliability of the device was sometimes impaired. That is, the quality of such resin impregnation has a great effect on the performance and reliability of the device.

Further, the coil impregnated with the resin as described above is set and heated and cured by a mold. However, since the operation is performed in a state where the resin is adhered, there is a problem that the workability is poor.

Furthermore, in such a VPI system, the amount of resin injected into the pressure vessel reaches several tens of times the amount of resin impregnated in the coil insulator because the coil is sufficiently immersed. The resin remaining in the impregnation process at this time is returned to the storage tank upon completion of the process, and is circulated between the impregnation tank and the storage tank.

However, circulating the surplus resin in this manner may cause contamination or impurities adhering to the surface of the impregnation tank or the coil to be mixed into the impregnated resin, thereby deteriorating the characteristics. In addition, circulating the impregnated resin causes the viscosity to rise relatively quickly due to the effects of temperature changes and impurities, so that new impregnated resin is replenished to maintain the viscosity, but this is also limited. In addition, there is a problem that the impregnated resin can be used only for a shorter time than the original storage life, and disposal of the impregnated resin that has become unusable has become a serious problem in terms of environment and cost.

[0009]

As described above, the conventional VP
The I-method had major problems in remaining bonds, workability and life of the impregnated resin, and disposal of the impregnated resin. The present invention has been made in view of the above circumstances, and it is possible to improve the impregnating property and electrical characteristics of a resin, and furthermore, it is possible to improve the impregnation and curing of electric equipment windings, which is advantageous in terms of environment and cost. The aim is to provide a method.

[0010]

According to the first aspect of the present invention,
A coil having an insulating layer formed around a conductor is disposed in a pressure vessel, the pressure inside the pressure vessel is reduced, and an impregnated resin is injected from the end of the coil.

In this case, the flow direction of the impregnated resin to be injected is unidirectional, so that the impregnation time is short and the number of voids can be reduced. According to the second aspect of the present invention, a plastic plate is applied as a release material to the surface of the coil having the insulating layer formed around the conductor, a heat-shrinkable tape is wound thereon, and the coil is impregnated with a resin. The resin is cured by heating.

[0012] In this case, by using a plastic plate as the release material, a result excellent in moldability and release properties can be obtained. According to a third aspect of the present invention, a coil having an insulating layer formed around a conductor is arranged in a mold with a gap, and after impregnating the coil with a resin, the gap in the mold is closed and the impregnated resin is filled. Is cured by heating.

[0013] With this configuration, it is possible to realize highly accurate coil molding in which a predetermined dimension is maintained by the mold during the heat curing of the impregnated resin. According to a fourth aspect of the present invention, a coil in which an insulating layer is formed around a conductor is inserted into a heat-shrinkable tube in advance, and after impregnating the coil with a resin, the impregnated resin is cured by heating.

In this way, the insulating layer can be kept loose during the resin impregnation, so that the resin impregnation speed can be increased and the resin can be cured while tightening the coil by the heating temperature during curing. .

According to a fifth aspect of the present invention, in the fourth aspect, the heat-shrinkable tube has a hole for gas permeation. According to a sixth aspect of the present invention, in the first to fifth aspects, the coil having an insulating layer formed around the conductor is a coil having a resin permeable layer formed between the conductor and the insulating layer.

In this case, the penetration rate of the resin can be greatly improved. According to a seventh aspect of the present invention, in the sixth aspect, the coil further includes a semiconductive layer formed on a resin permeable layer.

This makes it possible to alleviate the electric field in the resin permeable layer and improve the withstand voltage. In the invention according to claim 8, in claim 1, a resin detection sensor is disposed at an end opposite to the end at which the impregnating resin of the coil is injected, and the impregnating resin is detected based on detection information of the impregnating resin by the detection sensor. I try to stop the injection.

This makes it possible to stop unnecessary resin injection and to impregnate the coil with the resin without waste. According to a ninth aspect of the present invention, in the first aspect, the coil has a plurality of electrodes around which a conductor is wound, and the impregnation state of the resin can be measured from these electrodes.

In this way, even if the resin impregnation rate inside the coil may be different, it is possible to grasp the resin impregnation state. The invention according to claim 10 is the first invention.
In the description, a closed structure is formed between the coil end into which the impregnating resin is injected and the impregnating resin injection section. In this case, the impregnated resin can be efficiently injected from the end of the coil.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a schematic configuration of an impregnation apparatus to which a resin impregnation / curing method of the present invention is applied. In the figure, reference numeral 1 denotes a pressure vessel, to which a resin storage tank 4 is connected via a resin introduction pipe 3 having a valve 2. This resin storage tank 4
A thermosetting impregnated resin 5 is stored, and the impregnated resin 5 is pressurized with a gas 6 supplied from the outside, so that the impregnated resin 5 is stored inside the resin storage tank 4 via the resin introduction pipe 3. It is supplied by pressure. In this case, the surface of the impregnated resin 5 may be pressurized with the gas 6 using a piston or the like.

In the hollow portion of the pressure vessel 1, a coil 7 for a rotating electric machine is accommodated. This coil 7 has an insulating layer 702 formed around a conductor 701. The resin introduction pipe 3 is connected to the end of the coil 7.
In the illustrated example, the resin introduction pipe 3 is connected to only one end of the coil 7 via the connection portion 8, and the other end is connected to the cap 1.
1 is provided to prevent the impregnated resin 5 from flowing out from the other end.

In the drawings, reference numeral 9 denotes a pressure gauge for displaying the pressure inside the pressure vessel 1, and reference numeral 10 denotes a pressure reducing port for reducing the pressure inside the pressure vessel 1. In such a processing apparatus, a coil 7 for a rotating electric machine for impregnating a resin is disposed in a hollow portion of the pressure vessel 1, and a resin introduction pipe 3 is connected to an end of the coil 7 via a connection portion 8. .

In this state, the pressure inside the pressure vessel 1 is reduced through the pressure reducing port 10 and the resin introduction pipe 3
The impregnated resin is injected from the end of the coil 7 through the. In this case, the surface of the impregnated resin 5 of the resin storage tank 4 is pressurized by the external gas 6 and the impregnated resin 5 injected into the end of the coil 7 from the resin introduction pipe 3 is pressed into the insulating layer 702 from the inside of the coil 7. The pressure difference is increased.

FIG. 2 illustrates the flow of the impregnated resin 5 injected from the end of the coil 7. In this case, the impregnated resin 5 injected from the resin introduction pipe 3 to the end of the coil 7 is It flows into the space between the conductor 701 and the insulating layer 702 from the portion, and is further impregnated and impregnated while pushing the inside of the insulating layer 702 outward.

In this way, the impregnating resin 5 injected from the end of the coil 7 flows in one direction, so that the impregnating time is short and the number of voids can be reduced, and the impregnating properties and the electric characteristics can be reduced. It is possible to manufacture an excellent coil.

In the case of a transition twisted wire often used as the coil 7, the permeability of the impregnated resin 5 in the conductor 701 and the insulating layer 702 can be made relatively good. (Second Embodiment) The second embodiment relates to coil forming at the time of heat hardening. In this case, a coil 12 formed by winding an insulating tape 1202 around a conductor 1201 as shown in FIG. A plastic plate 13 for mold release is applied to the surface, and a heat-shrinkable tape 14 that shrinks when heated from above is wound thereon, and impregnated with the resin by the above-described method. I do. In this case, the melting point of the plastic plate 13 is 200 ° C.
As described above, a polyamide (nylon 66, 46, or the like) having a plate thickness of about 0.2 to 5.0 mm is used.

In this way, by using the plastic plate 13 as the release material, it is possible to obtain a result excellent in moldability and release properties as compared with the case where an iron plate or the like is used. (Third Embodiment) The third embodiment relates to a method of using a mold for coil forming by heat curing of an impregnated resin. In this case as well, as shown in FIG.
1, a coil 12 formed by winding an insulating tape 1202 and a release tape (not shown) further wound thereon are arranged in a lower mold 15 having a U-shaped cross section with a gap 16 therebetween, and the above-described method is employed. To impregnate the resin. In other words, in this case, when the resin is impregnated, the insulating layer made of the insulating tape 1202 of the coil 12 is kept from being tightened, so that the resin is easily impregnated and the resin that does not seep out from the insulating layer is dripped. It has a mold structure. After completion of the impregnation with the resin, the upper mold 17 having a U-shaped cross section shown in FIG. 4A or the upper mold 18 having a L-shaped cross section shown in FIG.
The mold is fixed to a predetermined size by being inserted into the gap 16 and tightened, and this state is maintained until the heat curing of the impregnated resin is completed.

The upper mold 17 having a U-shaped cross section or the upper mold 18 having an L-shaped cross section is selectively used depending on the type of the coil 12. With this configuration, the predetermined dimensions of the impregnated resin are maintained by the mold during the heat curing of the impregnated resin, so that highly accurate coil molding can be realized. Also in this case, the surface of the coil 12 is protected by using a plastic plate 13 for releasing between the coil 12 and the upper mold 17 or 18 as shown in FIGS. A product excellent in release property and workability is obtained. (Fourth Embodiment) The fourth embodiment relates to a method of using a heat-shrinkable tube for coil formation by heat curing of an impregnated resin.

In this case, a plastic plate having a melting point of 200 ° C. or more, for example, a plastic plate of polyamide (nylon 66, 46, etc.) or a rubber plate such as silicone rubber or EPDM (ethylene propylene rubber) is provided on the surface of the coil formed by winding an insulating tape around the conductor. A heat-resistant rubber in a shape is applied, and this is inserted into a heat-shrinkable tube to impregnate and harden the resin. In this case, a hole for gas permeation is formed in the upper part of the coil insertion portion of the heat-shrinkable tube to facilitate the evacuation.

FIG. 5 shows an example of coil forming by such a method.
No. 11 employs the method using the mold described in the third embodiment, and employs the method using the above-described heat-shrinkable tube only for the curved portion 212.

According to the coil molding using such a heat-shrinkable tube, the insulating layer can be kept loose during the resin impregnation, so that the resin impregnation speed can be increased, and the coil can be tightened by the heating temperature during curing. While the resin can be cured, it is easy to handle and has excellent mold release properties and workability. (Fifth Embodiment) In the fifth embodiment, the resin permeation layer at the interface between the conductor and the insulating layer is not positively expected only for the concavities and convexities of the conductor. Is provided to increase the impregnation speed.

In this case, in a coil formed by winding an insulating tape such as mica around a conductor, a non-woven fabric, a glass tape, a porous plastic sintered body, an embossed or a mesh is provided between the conductor and the insulating tape (insulating layer). A permeable layer formed alone or in an appropriate combination, such as a non-woven organic film or an embossed or mesh organic film and a non-woven fabric tape, is arranged.

In this way, the resin penetration speed is greatly improved, so that even in the case of, for example, a long coil, the resin can be uniformly impregnated at the end and the center of the coil without any time difference. Can be.

In this case, a semiconductive tape may be further wound on the resin permeable layer to form a semiconductive layer. In this case, the electric field in the resin permeable layer can be reduced, and the withstand voltage can be improved. (Sixth Embodiment) The sixth embodiment is a method for preventing a resin from inadvertently flowing out from the other end by a resin impregnation method in which a resin is injected from one end of a coil.

In this case, as described in the first embodiment, the resin is impregnated from one end of the coil, and a seal mechanism having a resin detection sensor is provided at the other end of the coil. With this configuration, when the resin impregnated between the conductor and the insulating layer from one end of the coil reaches the other end of the coil before being impregnated into the insulating layer, this is detected by the resin detection sensor. By stopping the injection of the resin by tightening the valve, the resin can be impregnated without waste. (Seventh Embodiment) In a seventh embodiment, a plurality of conductors such as aluminum sheets are partially wound around a coil formed by winding an insulating tape around a conductor to form electrodes. The degree of resin impregnation is detected by measuring the electric resistance or capacitance between the conductor and the conductor.

In this way, in the case of a long coil, even if the resin impregnation rates at the coil end portion and the central portion may differ, it is possible to detect that the impregnated resin has spread over the entire coil. . (Eighth Embodiment) In the eighth embodiment, a coil end to which resin is injected is sealed. In this case, as shown in FIG. 6A, a rubber packing 33 is provided between an end of the coil 31 having an insulating layer 312 formed around the conductor 311 and a connecting portion 32 for connecting a resin introduction pipe (not shown).
Alternatively, as shown in FIG. 3B, rubber seals 34 are interposed, and the space between them is sealed. In this case, the rubber packing 33 can be mounted in a sealed state by being pushed along the outer periphery of the insulating layer 312.
The rubber seal 34 can be mounted in a sealed state by applying liquid rubber or putty-like rubber between a slight clearance between the connection part 32 and the coil 31.

In this way, since the space between the end of the coil 31 and the connecting portion 32 can be sealed, the impregnated resin can be efficiently injected from the end of the coil 31. (Ninth Embodiment) This ninth embodiment also seals the coil end into which the resin is injected. In this case, the same parts as those of FIG. 6 are denoted by the same reference numerals, and as shown in FIG. 7, a coil 3 having an insulating layer 312 formed around a conductor 311 is formed.
A heat-shrinkable tube 35 is placed between 1 and a connecting portion 32 for connecting a resin introduction pipe (not shown), and the space therebetween is sealed. In this case, the end of the coil 31 and the connecting portion 32
Is covered with a heat shrink tube 35 in advance, and after the connection is established, the heat shrink tube 35 is
Is heated and shrunk to obtain a closed state. Also in this case, since the space between the end of the coil 31 and the connection portion 32 can be kept in a sealed state, the impregnated resin can be efficiently injected from the end of the coil 31.

[0038]

【Example】

(Example 1) 1.2 m of a transferred wire coil was prepared, and a glass-backed mica tape was laid on the wire coil by 1/2 and wound 10 times to form a coil insulating layer to form a coil.
Also, a 30 mm wide aluminum foil was wound around each of the position 10 cm from the coil end and the center of the conductor to form electrodes, and a polyester heat-shrink tape was wound around these.

Then, the coil constructed as described above is placed in a lower mold having a U-shaped cross section, and 1 mm is placed on both sides of the coil.
Thick nylon 66 was inserted. Further, it was placed in a pressure vessel, the coil end was connected to a resin introduction pipe, and these connections were sealed with a rubber-based putty.

In this case, the impregnated resin has a viscosity of 1 at 25 ° C.
The epoxy impregnated resin of Pons was used, and the impregnation conditions were maintained at a vacuum of 0.3 Torr or less in the pressure vessel, and the pressure of the impregnated resin was set to atmospheric pressure. Then, after impregnation with the resin, the resin introduction pipe at the coil end was removed, an upper mold having a U-shaped cross section was inserted, fixed to a predetermined size, and heat-cured. (Example 2) A 0.2 mm thick tape of polyester non-woven cloth was further halved between the strand coil of Example 1 and the insulating layer.
One turn was added. (Embodiment 3) Between the strand coil and the insulating layer of Embodiment 1, a glass tape having a thickness of 0.18 was further halved and wound once. (Example 4) Between the strand coil of Example 1 and the insulating layer, a tape having a thickness of 0.27 butted by DELNET X215 manufactured by Sanseki Co., Ltd. was used, and one turn was inserted. (Example 5) Between the strand coil of Example 1 and the insulating layer, a tape in which DELNET X215 of Sansei Co., Ltd. and polyester non-woven cloth 0.2mm thick were butted and one turn was inserted.

In the cases of Examples 1 to 5 in which the resin impregnation was performed as described above, the resin impregnation speed was detected by the capacitance between the electrodes provided on the coil, and the result shown in FIG. As for V-tan δ, the results shown in A in FIG. 9 were obtained. Note that A to E in FIG. 8A correspond to the first to fifth embodiments described above.

Thus, for Examples 1 to 5,
It was compared with the conventional vacuum / pressure impregnation method. As a conventional example, after the coil is manufactured, a terminal treatment is performed so that the resin does not enter from both ends of the coil, and this is put into a pressure vessel, and kept at a vacuum of 0.3 Torr or less. After a certain period of time in vacuum, switch to pressurization 6 kg
/ Cm ² .

When the resin impregnation speed of the conventional example in which the resin impregnation was performed as described above was detected from the capacitance, the result shown in FIG. 8B was obtained, and furthermore, V-tan δ was obtained.
The result shown in B in FIG. 9 was obtained.

As a result, the impregnation rate of the resin in Examples 1 to 5 shown in FIG. 8A was smaller than that of the conventional example shown in FIG. Since a large differential pressure can be obtained by the flow, the impregnation speed can be increased, and the impregnation time can be significantly reduced. In Examples 1 to 5 indicated by A in FIG.
Significant improvement was also confirmed for the δ characteristic, and it can be estimated that voids were further reduced.

In addition, in Examples 1 to 5, all the resin once sent into the pressure vessel is sent into the coil and does not return to the storage tank. Since there is no worry about possible time,
Almost no waste resin can be used.

[0046]

As described above, according to the present invention, while reducing the pressure inside the pressure vessel in which the coil is disposed, the impregnated resin is injected from the end of the coil, and the flow direction of the impregnated resin is set to one direction. As a result, the impregnation time can be shortened and the number of voids can be reduced, so that the impregnating property of the resin and the electrical characteristics can be improved. Further, the impregnated resin injected into the coil is not reused, and as a result, waste resin can be completely eliminated, which is advantageous in terms of environment and cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an impregnation processing apparatus to which the present invention is applied.

FIG. 2 is a diagram illustrating a flow of an impregnated resin injected from an end of the coil according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a second embodiment of the present invention.

FIG. 4 is a diagram for explaining a third embodiment of the present invention.

FIG. 5 is a diagram for explaining a fourth embodiment of the present invention.

FIG. 6 is a diagram for explaining an eighth embodiment of the present invention.

FIG. 7 is a view for explaining a ninth embodiment of the present invention.

FIG. 8 is a diagram for comparing and explaining the resin impregnation hardening method of the present invention and a conventional vacuum pressure impregnation method.

FIG. 9 is a diagram for comparing and explaining a resin impregnation curing method of the present invention and a conventional vacuum pressure impregnation method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pressure vessel, 2 ... Valve, 3 ... Resin introduction pipe, 4 ... Resin storage tank, 5 ... Impregnated resin, 6 ... Gas, 7 ... Coil, 701 ... Conductor, 702 ... Insulating layer, 8 ... Connection part, 9 ... Pressure gauge, 10: pressure reducing port, 11: cap, 12: coil, 1201: conductor, 1202: insulating tape, 13: plastic plate, 14: tape, 15: lower mold, 16: gap, 17: U-shaped cross section 18: L-shaped upper mold, 21: coil, 211: linear part, 212: curved part, 31: coil, 311: conductor, 312: insulating layer, 32: connecting part, 33 ... Rubber packing, 34: rubber seal, 35: heat shrink tube.

Claims (10)

[Claims] 1. An electric apparatus comprising: a coil having an insulating layer formed around a conductor; and a pressure vessel for reducing pressure inside the pressure vessel and injecting an impregnated resin from an end of the coil. Method of impregnating and hardening the windings with resin. 2. A plastic plate as a release material is applied to the surface of a coil having an insulating layer formed around a conductor, and a heat-shrinkable tape is wound thereon, and the coil is impregnated with a resin. A method of impregnating and curing a resin for a winding of an electric device, which comprises curing the resin. 3. A coil in which an insulating layer is formed around a conductor is placed in a mold with a gap, and after impregnating the coil with a resin, the gap in the mold is closed and the impregnated resin is heat-cured. A method of impregnating and hardening a resin for a winding of an electric device, the method comprising: 4. A coil having an insulating layer formed around a conductor,
A method for impregnating and curing a resin winding of an electric device, comprising inserting the coil into a heat-shrinkable tube in advance, impregnating the coil with a resin, and curing the impregnated resin by heating. 5. The method according to claim 4, wherein the heat-shrinkable tube has a hole for gas permeation. 6. A coil having an insulating layer formed around a conductor,
6. The method of impregnating and curing a resin winding of an electric device according to claim 1, wherein a resin permeable layer is formed between the conductor and the insulating layer. 7. The method according to claim 6, wherein the coil further comprises a semiconductive layer formed on the resin permeable layer. 8. A resin detection sensor is disposed at an end of the coil opposite to the end into which the impregnated resin is injected, and the impregnated resin is stopped from being injected based on detection information of the impregnated resin by the detection sensor. The method for impregnating and curing a resin winding of an electric device according to claim 1. 9. The electric device winding according to claim 1, wherein the coil has a plurality of electrodes around which a conductor is wound, and the impregnation state of the resin can be measured from these electrodes. Resin impregnation and curing method. 10. The method for impregnating and curing a resin winding of an electric device according to claim 1, wherein a portion between the coil end into which the impregnating resin is injected and the impregnating resin injection portion is formed in a sealed structure.