JP3618956B2 - Resin impregnation and curing method for electrical equipment windings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin impregnation / curing method for electrical equipment windings used in large rotating electrical machines such as water turbine generators and turbine generators.
[0002]
[Prior art]
Conventionally, as a resin impregnation method for large coils of large rotating electrical machines such as water turbine generators and turbine generators, first, a predetermined number of composite insulating tapes mainly made of mica as an insulating material are wound around the coils to place them in a pressure vessel. In general, a method is adopted in which pressure reduction and pressure impregnation (VPI) is performed, and then the impregnated resin is cured by applying a mold or the like.
[0003]
In this method, in the first-stage pressure reduction impregnation, the degree of vacuum is reduced to about 0.1 Torr, and then the resin is injected little by little to fill the coil. Further, by further reducing the pressure, the exhaust of the gas in the coil insulator and the replacement / penetration of the resin are promoted to increase the resin impregnation rate.
[0004]
However, in this method, since the resin is impregnated from the outside of the coil, it is difficult to completely discharge the gas in the insulator and replace it with the resin.
Therefore, after moderately reduced pressure impregnation, by switching to pressurization and crushing the residual gas, the gas (void) present in the insulator is reduced to further improve the resin impregnation rate. Yes.
[0005]
However, even if it does in this way, the void in an insulator cannot be removed completely. This is because when the gas is present in the coil insulator, the coil is encased in the resin, and in the fine part of the insulator, the gas is not sufficiently replaced with the gas due to the viscosity of the resin, and the void is not formed. It is a cause of remaining. If voids remain in the insulator, in the case of a coil that is used under high voltage, a partial discharge starting from the void can easily occur, greatly affecting the coil life and improving the reliability of the equipment. There was a loss. That is, the quality of such resin impregnation has a great influence on the performance and reliability of the device.
[0006]
In addition, the coil impregnated with the resin in this way is heated and cured by setting a mold, but there is a problem that workability is poor because the operation is performed with the resin adhered.
[0007]
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 when the process is completed, and is circulated between the impregnation tank and the storage tank.
[0008]
However, circulating the surplus resin in this way may cause dirt and impurities adhering to the impregnation tank and the coil surface to be mixed in the impregnation resin, resulting in deterioration of characteristics. In addition, circulation of the impregnating resin increases the viscosity relatively quickly due to the influence of temperature change and impurities, so that a new impregnating resin is replenished to maintain the viscosity. In addition, there is a problem that it can be used only in a time shorter than the original storage life. Furthermore, discarding the impregnated resin that can no longer be used is a serious problem in terms of environment and cost.
[0009]
[Problems to be solved by the invention]
As described above, the conventional VPI system has significant problems in the residual void , workability, the life of the impregnated resin, and disposal of the impregnated resin.
The present invention has been made in view of the above circumstances, and can improve the impregnation property and electrical characteristics of the resin, and can also improve the resin impregnation and curing of the electrical device winding, which is advantageous in terms of environment and cost. It aims to provide a method.
[0010]
[Means for Solving the Problems]
In the invention corresponding to claim 1, a coil formed by applying a plastic plate as a release material to the surface of an insulating layer formed around a conductor and winding a heat-shrinkable tape thereon is disposed in the pressure vessel. At the same time as reducing the pressure inside the container , an impregnating resin is injected under pressure between the conductor and the insulating layer through a resin introduction pipe connected to one end of the coil , and then the impregnating resin is heated and cured.
[0011]
In this way, the impregnation resin to be injected flows in the flow direction, so that the impregnation time is fast and the number of voids can be reduced. Moreover, the result excellent in the moldability and mold release property is obtained by using a plastic plate as a mold release material.
[0012]
The invention corresponding to claim 2 is the resin impregnation / curing method for an electric device winding according to claim 1 wherein resin detection sensors are arranged at one end and the other end of the coil into which the impregnation resin is injected. The injection of the impregnated resin is stopped by the detection information of the impregnated resin by the detection sensor.
[0013]
If it does in this way, injection | pouring of useless resin can be stopped and resin can be impregnated without waste in a coil.
[0014]
According to a third aspect of the present invention, there is provided a resin impregnation / curing method for an electrical equipment winding according to the first aspect of the present invention, wherein a plurality of electrodes each having a conductor wound around a coil are provided, and the resin is formed from these electrodes. It is possible to measure the impregnation state.
[0015]
The invention corresponding to claim 4 is the resin impregnation / curing method for an electric device winding according to the invention corresponding to claim 1, in which a sealed structure is provided between one end of the coil into which the impregnation resin is injected and the resin introduction pipe. Form.
[0016]
The invention corresponding to claim 5 is a state in which an insulating layer in which an insulating tape is wound around a conductor is formed, and a coil formed by winding a release tape thereon is disposed with a gap in the lower mold In the pressure vessel, the pressure inside the pressure vessel is reduced, and simultaneously, the impregnation resin is pressurized and injected between the conductor and the insulating layer through a resin introduction pipe connected to one end of the coil. The upper mold is inserted into the gap between the lower mold and the coil at the time of heat curing, and the mold is fixed to a predetermined size and maintained in a clamped state until the heat curing is completed.
[0017]
In this way, in addition to obtaining the same effect as the invention corresponding to claim 1, it is possible to realize highly accurate coil forming in which the predetermined dimensions are maintained by the mold during the heat curing of the impregnating resin. Become.
[0018]
The invention corresponding to claim 6 is the resin impregnation / curing method for electrical equipment windings of the invention corresponding to claim 1 or claim 5, wherein the coil formed with an insulating layer around the conductor is composed of a conductor and an insulating layer. A resin permeation layer is formed between them.
[0019]
In this way, the penetration speed of the resin can be greatly improved.
The invention corresponding to claim 7 is the resin impregnation / curing method for an electric device winding according to the invention corresponding to claim 6, wherein the coil is formed by forming a semiconductive layer on the resin permeation layer.
If it does in this way, the electric field in the penetration layer of resin can be eased and voltage endurance can be improved.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a schematic configuration of an impregnation processing apparatus to which the resin impregnation / curing method of the present invention is applied. In the figure, reference numeral 1 denotes a pressure vessel, and a resin storage tank 4 is connected to the pressure vessel 1 via a resin introduction pipe 3 having a valve 2. The resin storage tank 4 stores a thermosetting impregnating resin 5, and pressurizes the surface of the impregnating resin 5 with a gas 6 supplied from the outside, thereby allowing the storage impregnating resin 5 to pass through the resin introduction pipe 3. The resin storage tank 4 is supplied with a predetermined pressure. In this case, the surface of the impregnated resin 5 may be pressurized with the gas 6 using a piston or the like.
[0021]
A rotary electric machine coil 7 is accommodated in the hollow portion of the pressure vessel 1. 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 as described above. In the illustrated example, the resin introduction pipe 3 is connected to only one end portion of the coil 7 via the connection portion 8, and the cap 11 is provided at the other end portion to prevent the impregnation resin 5 from flowing out from the other end portion. I am doing so.
[0022]
In the drawing, 9 is a pressure gauge for displaying the pressure inside the pressure vessel 1, and 10 is a pressure reducing port for reducing the pressure inside the pressure vessel 1.
Thus, in such a processing apparatus, a coil 7 for a rotating electrical machine that impregnates the resin is disposed in the hollow portion of the pressure vessel 1, and the resin introduction pipe 3 is connected to the end of the coil 7 via the connection portion 8. .
[0023]
From this state, the pressure inside the pressure vessel 1 is reduced through the pressure reducing port 10 and at the same time, the impregnating resin is injected from the end of the coil 7 through the resin introduction pipe 3. In this case, the surface of the impregnating resin 5 of the resin storage tank 4 is pressurized with the external gas 6, and the impregnating resin 5 injected into the end of the coil 7 from the resin introduction pipe 3 is pressurized, so that the insulating layer 702 is applied from the inside of the coil 7. The pressure difference is increased.
[0024]
FIG. 2 illustrates the flow of the impregnating resin 5 injected from the end of the coil 7. In this case, the impregnating resin 5 injected from the resin introduction pipe 3 to the end of the coil 7 is a conductor from the end of the coil 7. It flows between 701 and the insulating layer 702, and further penetrates and impregnates while pushing the insulating layer 702 outward.
[0025]
Thus, since the impregnation resin 5 injected from the end of the coil 7 flows in one direction, the impregnation time is fast and the voids can be reduced, and the impregnation and electrical characteristics are excellent. A coil can be manufactured.
[0026]
In the case of a transition stranded wire often used as the coil 7, the permeability of the impregnating resin 5 between the conductor 701 and the insulating layer 702 can be made relatively good.
(Second Embodiment)
This second embodiment relates to coil forming at the time of heat curing. In this case, as shown in FIG. 3, the surface of the coil 12 formed by winding an insulating tape 1202 around a conductor 1201 is used for mold release. A plastic plate 13 is applied, a heat-shrinkable tape 14 that shrinks when heated from above is wound, and the resin is impregnated by the method described above, and then the impregnated resin is heated and cured to perform coil molding. In this case, polyamide (nylon 66, 46, etc.) having a melting point of 200 ° C. or more and a thickness of about 0.2 to 5.0 mm is used as the plastic plate 13.
[0027]
In this way, by using the plastic plate 13 as the release material, a result excellent in moldability and release properties can be obtained as compared with the case where an iron plate or the like is used.
(Third embodiment)
This third embodiment relates to a method of using a mold for coil molding by heat curing of an impregnating resin. In this case as well, a coil 12 formed by winding an insulating tape 1202 around a conductor 1201 as shown in FIG. A surface of which a release tape (not shown) is further wound is placed on the surface with a gap 16 in the lower mold 15 having a U-shaped cross section, and the resin is impregnated by the method described above. That is, 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 clamped to facilitate the impregnation of the resin and the resin that has exuded from the insulating layer is not dripped down. It has a mold structure. After the resin impregnation, the upper mold 17 having a U-shaped section shown in FIG. 4A or the upper mold 18 having an L-shaped section shown in FIG. By inserting in 16, the mold is fixed to a predetermined size and tightened, and this state is maintained until the heat curing of the impregnating resin is completed.
[0028]
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.
In this way, since the predetermined dimension is maintained by the mold when the impregnating resin is heat-cured, 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 the mold between the coil 12 and the upper mold 17 or 18 as shown in FIGS. A product excellent in releasability and workability can be obtained.
(Fourth embodiment)
This fourth embodiment relates to a method of using a heat-shrinkable tube for coil forming by heat curing of an impregnating resin.
[0029]
In this case, the coil surface formed by winding an insulating tape around the conductor has a melting point of 200 ° C. or more, for example, a plastic plate of polyamide (nylon 66, 46, etc.), or a crumbly heat resistant material such as silicone rubber or EPDM (ethylene propylene rubber). A conductive rubber is applied, and this is inserted into a heat-shrinkable tube, and the resin is impregnated and cured. In this case, a gas-permeable hole is formed in the upper part of the coil insertion portion of the heat-shrinkable tube to facilitate evacuation.
[0030]
FIG. 5 shows an example of coil forming by such a method. Here, the straight part 211 of the coil 21 adopts the method using the mold described in the third embodiment, and the curved part. The method using the heat-shrinkable tube described above is adopted only for 212.
[0031]
According to the coil molding using such a heat-shrinkable tube, since the insulating layer can be kept loose at the time of resin impregnation, the resin impregnation rate can be increased, and the resin is tightened by the heating temperature at the time of curing. Curing can be performed, and furthermore, handling is easy, and an excellent mold release property and workability can be obtained.
(Fifth embodiment)
In the fifth embodiment, a resin penetration layer is positively provided at the interface between the conductor and the insulating layer so far, which is not expected only for the unevenness of the conductor, so as to increase the impregnation speed. I have to.
[0032]
In this case, the coil formed by winding an insulating tape such as mica around the conductor, and organic material with non-woven fabric, glass tape, porous plastic sintered body, embossed or mesh between these conductor and insulating tape (insulating layer) A permeation layer made of a film or an embossed or meshed organic film and a tape bonded with a non-woven fabric is used alone or in combination as appropriate.
[0033]
In this way, the resin penetration rate is greatly improved, so that even in the case of a long coil, for example, the resin can be impregnated uniformly at the coil end and the center without any time difference.
[0034]
In this case, a semiconductive layer may be formed by further winding a semiconductive tape from above the resin permeation layer. If it carries out like this, the electric field in the osmosis | permeation layer of resin can be relieve | moderated, and voltage endurance can be improved.
(Sixth embodiment)
The sixth embodiment is a resin impregnation method in which resin is injected from one end of a coil and is a method for preventing the resin from inadvertently flowing out from the other end.
[0035]
In this case, as described in the first embodiment, a resin impregnation is performed from one end of the coil, and a seal mechanism having a resin detection sensor is provided at the other end of the coil. In this way, 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 impregnating the insulating layer, this is detected by the resin detection sensor. The resin can be impregnated without waste by stopping the injection of the resin by closing the valve.
(Seventh embodiment)
In the seventh embodiment, an electrode is formed by partially winding a conductor such as an aluminum stay around a coil formed by winding an insulating tape around a conductor to form an electrode, and an electrical resistance between the electrode and the conductor or The degree of resin impregnation is detected by measuring the capacitance.
[0036]
In this way, in the case of a long coil, even if the resin impregnation speed differs between the coil end and the central portion, it can be detected that the impregnation resin has spread throughout the coil.
(Eighth embodiment)
In the eighth embodiment, a coil end into which resin is injected is sealed. In this case, as shown in FIG. 6A, a rubber packing 33 is provided between the end of the coil 31 in which the insulating layer 312 is formed around the conductor 311 and the connection portion 32 connecting the resin introduction pipe (not shown). As shown in FIG. 2 (b), rubber seals 34 are interposed, and the space between them is formed in a sealed state. In this case, the rubber packing 33 can be attached in a sealed state by being pushed along the outer periphery of the insulating layer 312, and the rubber seal 34 can be used for liquid rubber or the like during a slight clearance between the connection portion 32 and the coil 31. It can be installed in a sealed state by applying putty rubber.
[0037]
In this way, since the gap between the end of the coil 31 and the connection portion 32 can be sealed, the impregnation resin can be efficiently injected from the end of the coil 31.
(Ninth embodiment)
In the ninth embodiment, the coil end into which the resin is injected is also sealed. In this case, as shown in FIG. 7 in which the same parts as those in FIG. 6 are given, heat is generated between the coil 31 in which the insulating layer 312 is formed around the conductor 311 and the connection part 32 connecting the resin introduction pipe (not shown). The shrinkable tube 35 is covered, and the space between the two is configured in a sealed state. In this case, a heat-shrinkable tube 35 is put on the end of the coil 31 and the connecting portion 32 in advance, and after connecting between these, the heat-shrinkable tube 35 is heated and contracted with hot air such as a dryer to obtain a sealed state. ing.
Even if it does in this way, since between the coil 31 end and the connection part 32 can be made into a sealing state, impregnation resin can be efficiently inject | poured from the coil 31 end.
[0038]
【Example】
(Example 1)
The transferred wire coil was prepared in a length of 1.2 m, and a glass-lined mica tape was halved and wound 10 times around this wire coil to form a coil insulating layer. In addition, an aluminum stay having a width of 30 mm was wound around a position 10 cm from the end of the coil and the center of the conductor to form an electrode, and a polyester heat shrink tape was wound around these.
[0039]
The coil thus configured was placed in a lower die having a U-shaped cross section, and nylon 66 having a thickness of 1 mm was inserted on both sides of the coil. Furthermore, it put in the pressure vessel, and while connecting the coil end to the resin introduction pipe, these connection parts were sealed with the rubber putty.
[0040]
In this case, the impregnating resin was an epoxy impregnating resin having a viscosity of 25 ° C. and 1 pons. The impregnation conditions were maintained at a vacuum degree of 0.3 Torr or less in the pressure vessel, and the pressure of the impregnating resin was set to atmospheric pressure. Then, after impregnation with the resin, the resin introduction pipe at the coil end was removed, and an upper mold having a U-shaped cross section was inserted, and fixed to a predetermined dimension, followed by heat curing.
(Example 2)
Between the strand coil of Example 1 and the insulating layer, a polyester non-woven cloth 0.2 mm thick tape was further halved and added once.
(Example 3)
Between the wire coil of Example 1 and the insulating layer, a glass tape having a thickness of 0.18 was further halved and one turn was added.
(Example 4)
Between the wire coil of Example 1 and the insulating layer, a tape of 0.27 thickness was further abutted with DELNET.X215 of Sanki Co., Ltd., and one turn was inserted.
(Example 5)
Between the wire coil of Example 1 and the insulating layer, a DELNET.X215 of Sanki Co., Ltd. and a tape bonded with a polyester non-woven cloth 0.2 mm thick were butted together and a single turn was inserted.
[0041]
In the case of Examples 1 to 5 where the resin impregnation was performed in this way, the resin impregnation speed was detected by the capacitance between the electrodes provided in the coil, and the result shown in FIG. Further, for V-tan δ, the result shown in A in FIG. 9 was obtained. In addition, AE in Fig.8 (a) respond | corresponds to Examples 1-5 mentioned above.
[0042]
Thus, Examples 1 to 5 were compared with those obtained by the conventional vacuum / pressure impregnation method. As a conventional example here, after the coil is manufactured, terminal treatment is performed so that the resin does not enter from both ends of the coil, this is placed in a pressure vessel, held at a vacuum degree of 0.3 Torr or less, deaerated, and then impregnated resin is injected. Then, after elapse of a certain time in a vacuum, the pressure was switched to pressurization and impregnation was performed at 6 kg / cm ² .
[0043]
For the conventional example in which the resin impregnation was performed in this manner, the resin impregnation rate was detected from the capacitance. As a result, the result shown in FIG. 8B was obtained, and V-tan δ was represented by B in FIG. The results shown are obtained.
[0044]
As a result, as for the impregnation speed of the resin, compared with the conventional example shown in FIG. 8B, for Examples 1 to 5 shown in FIG. Since the differential pressure can be increased, it is possible to increase the impregnation speed, and the impregnation treatment time can be greatly shortened. In addition, in Examples 1 to 5 shown by A in FIG. 9, it can be confirmed that the tan δ characteristic is greatly improved, and voids are further reduced.
[0045]
In addition, in Examples 1-5, since the resin once sent into the pressure vessel is all sent into the coil and does not return to the storage tank, a large storage tank can be dispensed with and the usable time of the resin can be reduced. Since there is no need to worry, almost no waste resin can be used.
[0046]
【The invention's effect】
As described above, according to the present invention, the impregnation time is reduced by injecting the impregnation resin from the end of the coil while reducing the pressure inside the pressure vessel in which the coil is disposed, and by making the flow direction of the impregnation resin one direction. In addition, the voids can be reduced and the electrical properties can be improved along with the resin impregnation.
Further, the impregnating resin injected into the coil is not reused. As a result, no waste resin can be used, 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 view for explaining the flow of impregnating resin injected from the coil end portion of 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 view for explaining an eighth embodiment of the present invention.
FIG. 7 is a diagram for explaining a ninth embodiment of the present invention.
FIG. 8 is a view for comparing and explaining a resin impregnation curing method of the present invention and a conventional vacuum pressure impregnation method.
FIG. 9 is a view for comparing and explaining a resin impregnation curing method of the present invention and a conventional vacuum pressure impregnation method.
[Explanation of symbols]
1 ... pressure vessel,
2 ... Valve,
3 ... resin introduction pipe,
4 ... Resin storage tank,
5 ... impregnating resin,
6 ... gas,
7 ... Coil,
701: Conductor,
702 ... an insulating layer,
8 ... connection part,
9 ... Pressure gauge,
10 ... decompression port,
11 ... Cap,
12 ... Coil,
1201 ... conductor,
1202 ... insulating tape,
13 ... Plastic plate
14 ... tape,
15 ... Lower mold,
16 ... Gap,
17 ... Upper mold with U-shaped cross section,
18 ... Upper mold with L-shaped cross section,
21 ... Coil,
211 ... straight section,
212 ... curve part,
31 ... Coil,
311: Conductor,
312 ... Insulating layer,
32 ... connection part,
33 ... Rubber packing,
34 ... rubber seal,
35 ... Heat shrinkable tube.

Claims (7)

A coil formed by applying a plastic plate as a release material to the surface of the insulating layer formed around the conductor and winding a heat-shrinkable tape thereon is disposed in the pressure vessel, and simultaneously reducing the pressure inside the pressure vessel. after the impregnated resin was pressure injected between the conductor and the insulating layer through the connected resin inlet pipe at one end of the coil, the electrical equipment windings, characterized in that is cured by heating impregnation resin Resin impregnation and curing method. 2. The resin detection sensor is disposed at one end and the other end of the coil into which the impregnation resin is injected, and injection of the impregnation resin is stopped by detection information of the impregnation resin by the detection sensor. Method of resin impregnation and curing of electrical equipment windings. 2. The method of impregnating and curing a resin winding of an electric device according to claim 1, wherein a plurality of electrodes each having a conductor wound around the coil are provided, and the impregnation state of the resin can be measured from these electrodes . 2. The resin impregnation / curing method for an electric device winding according to claim 1, wherein a sealing structure is formed between one end of the coil into which the impregnation resin is injected and the resin introduction pipe . An insulating layer in which an insulating tape is wound around a conductor is formed, and a coil formed by winding a release tape on the conductor is housed in a pressure vessel in a state of being arranged with a gap in the lower mold, The pressure inside the pressure vessel is reduced, and at the same time, an impregnating resin is injected between the conductor and the insulating layer through a resin introduction pipe connected to one end of the coil, and then the lower mold is heated and cured. A resin impregnation / curing method for electrical equipment windings , characterized in that an upper mold is inserted into a gap with the coil and the mold is fixed to a predetermined size and kept in a clamped state until heat curing is completed . The coil having an insulating layer formed around a conductor is a resin-impregnated layer formed between the conductor and the insulating layer. Curing method. 7. The method for impregnating and curing an electric device winding according to claim 6, wherein the coil is formed by forming a semiconductive layer on a resin-permeable layer.

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