JP2000287401A - Stator coil of high voltage rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain coil insulation by preventing generation of air gaps in cured impregnated resin in the periphery of each strand insulated wire, concerning a strand coil of a high voltage rotating machine stator. SOLUTION: In lamination material 7 of a strand coil 2 constituting a stator coil, a prepreg layer 7a and a prepreg layer 7b are formed as a plurality of prepreg layers which have adjustable resin melting temperatures and are different in melting temperature. A base material layer 7c is made a center, and the prepreg layers 7b and 7a are arranged in this order toward both outsides in such a manner that the resin melting temperature becomes high. By this constitution, rapid curing of melted resin is made unnecessary by fluidity adjustment of the melted resin and the more accurate estimation of the diffused state, when the strand coil is pressure-molded at a high temperature, so that generation of air gaps due to foaming which is to be caused by rapid curing reaction can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator coil for a high-voltage rotating machine, and more particularly to a component coil of the stator coil formed by applying a high-temperature pressure to a wire-insulated wire bundle.

[0002]

2. Description of the Related Art Conventionally, as a stator coil of a high-pressure rotating machine of this type, there is known a stator coil whose cross-sectional configuration is exemplified in a sectional view of a stator coil of a high-pressure rotating machine shown in FIG. By the way,
There are two types of stator coil formation methods for high-voltage rotating machines: single coil impregnation and full coil impregnation. First, coil single impregnation involves multiple insulated wire insulated wire conductors. After winding and aligning, high-pressure molding is performed to form a wire coil, and this wire coil is wound several times with a main insulating tape such as a resin-impregnated mica tape to form a ground insulating layer. This coil is formed and set in a mold, and is impregnated with a thermosetting resin and heat-cured to form a predetermined coil. This coil is often used for forming a stator coil of a large machine.

[0003] Further, in the coil total impregnation method, all the resin-impregnated coils to be used are inserted into slots of a stator core, interlayer insulation and wedges are arranged, and then the stator core and the coil are integrated into a heat. It is used for impregnating a curable resin and heat-curing it, and is widely used in large machines or small machines. The stator coil of the present invention is based on the coil impregnation method.

[0004] Here, in Fig. 4, Fig. 4 (a) illustrates an overall cross-sectional configuration of a stator core slot portion including a stator coil of a high-voltage rotating machine, wherein 1 is a stator coil, 2 Is a wire coil formed by winding and aligning a wire insulated wire a plurality of times and then performing high-temperature pressure molding; 3, a main insulating layer which is impregnated and cured with an insulating resin and functions as a ground insulating layer;
Is an interlayer insulation inserted between the upper and lower stator coils accommodated in the core slot, 15 is a stator core, and 16 is a wedge.

FIG. 4 (b) shows an example of a cross-sectional structure of the wire coil 2 in the stator coil 1, wherein 4 is a wire insulated wire and 6 is a winding slot between adjacent wire wires. Laminated materials 10 arranged in the vertical direction are voids generated in the cured impregnated resin. Here, wire insulated wire 4
For, the illustration of the wire insulation layer applied to the wire conductor is omitted.

The laminated material 6 functions as an insulating intermediate partition for arranging the wires to avoid the occurrence of irregularities in the arrangement of the wound insulated wires, ie, the misalignment between the wires. At the same time, it also functions as a widely dispersed resin supply source for sufficiently filling the space formed by abutting the corners of the individual wires with the insulating resin. The prepreg layer is formed by providing a prepreg layer formed on both sides of a material layer and previously containing an insulating resin to be used.

[0007]

In the stator coil of the high-voltage rotating machine formed by the coil impregnation method as described above, the formation of the wire coil 2 shown in FIG. Avoiding the generation of the voids 10 in the cured impregnated resin in the vicinity of the above and the occurrence of the misalignment in the arrangement between the individual wires are important matters in the wire coil forming process.

[0008] Here, the air gap is a cause of deteriorating both the insulation characteristics and the heat radiation characteristics of the wire coil. That is, local heating is generated due to a difference in thermal conductivity between the gap and the resin-filled portion.In addition, damage inside the wire coil generated in the gap due to the influence of the electromagnetic vibration gradually expands to the ground insulating layer. If a partial discharge occurs in a near high electric field portion, the insulation function is deteriorated, which may eventually lead to coil insulation breakdown.

Further, the occurrence of misalignment between the individual wires and between the wires having irregularities may be caused by the concentration of an electric field near the gap generated at a required resin-filled portion where the corners of the individual wires are abutted. By enlarging the portion, the chance of occurrence of partial discharge in the above-mentioned void portion is increased, and the deterioration of the coil insulation function is accelerated.

In order to solve the above-mentioned problems, in the prior art, as shown in FIG. 4 (b), a prepreg layer formed by preliminarily containing a resin to be used is provided on both sides of the base material layer. The laminated material 6 is further used as a dispersed source of an insulating resin for sufficiently filling the space formed by abutting the corners of the individual wires constituting the wire coil with the resin. As an insulating intermediate partition for arranging each of the element wires, it is arranged between the adjacent element wires.

However, in the conventional resin filling with a laminated material of one prepreg layer as described above, there are the following problems regarding the melting point of the resin impregnated with the prepreg layer. 1) When the melting point of the prepreg layer is lowered: The resin easily flows, and requires rapid curing of the resin to prevent excessive flow. Foam. This foam forms the void after cooling. In addition, since the flowing direction of the molten resin is uncertain and easy to flow, it is necessary to repair or clean the resin flowing excessively, thereby increasing the required man-hours.

2) When the melting point of the prepreg layer is increased Foaming is reduced, but it is necessary to increase the processing temperature in order to sufficiently fill the required resin with sufficient detail. There is a possibility that a thermal adverse effect on each of the element wires or other peripheral materials may be large.

Further, when the processing temperature is lowered, voids are generated in the unfilled portion of the insulation due to lack of fluidity of the insulating resin, and the required fine details are not filled, so that the adhesive force between the above-mentioned individual wires decreases. There is a possibility that the wire may be misaligned due to wire collapse as described above.

As described above, the voids generated in the cured impregnated resin around each of the wire insulated wires are caused by the hardening mixed with the insulating resin flowing out of the prepreg layer of the laminated material during the high-temperature press molding of the wire coil. It is generated by foaming during a rapid curing reaction of the resin, or due to insufficient filling at a required filling portion due to excessive or insufficient fluidity of the insulating resin at the time of the molding, and the once formed void is Since there is no resin penetration path, it is difficult to impregnate the voids with the thermosetting resin forming the main insulating layer in the wire coil and to eliminate the voids even during the heat curing treatment. Becomes Further, the melting point of the prepreg layer is related to the diffusion of the insulating resin in the permeation zone at the time of high-temperature press molding, and is greatly related to the misalignment of the element wires.

In view of the above, the present invention relates to a hardened impregnation around the wire, which is a component of the stator coil of the high-voltage rotating machine and is formed by high-temperature pressing of the wire insulated wire bundle. A stator for a high-voltage rotating machine capable of maintaining the insulation performance of the stator coil by avoiding the occurrence of voids in the resin and the occurrence of the wire misalignment, and improving the stability and reliability of the rotating machine operation. It is intended to provide a coil.

[0016]

In order to achieve the above object, a stator coil for a high-voltage rotating machine according to the present invention has the following features. 1) The invention according to claim 1 is an element in which the element conductor is provided with element insulation. While winding the insulated wire a plurality of times, high-temperature press molding is performed on the wire insulated wire bundle in which an insulating laminated material is formed as an intermediate partition in the longitudinal direction of the winding slot between the adjacent wire wires. The coil was formed by applying a thermosetting resin to a resin-impregnated coil formed by providing a resin-impregnated main insulating layer on the element coil and heating and curing the resin-impregnated coil. In the stator coil of the high-pressure rotating machine, the laminated material includes a plurality of prepreg layers formed by previously containing resins to be used having different melting temperatures.

According to a second aspect of the present invention, in the stator coil of the high-pressure rotating machine according to the first aspect, the plurality of prepreg layers provided on the laminated material are formed around the base material layer of the laminated material. It is arranged so that the resin melting temperature becomes higher sequentially toward the outside.

According to a third aspect of the present invention, in the stator coil of the high-pressure rotating machine according to the first aspect, the laminated material penetrates the base material layer and each prepreg layer to form a passage for the molten resin. A suitable number of through holes having an appropriate area are provided at appropriate positions corresponding to the positions of the individual wires constituting the wire coil.

As described above, the present invention functions as an insulating intermediate partition for arranging the plurality of wire wires wound with the base material layer, and at the same time, a required filling between the scattered wire wires. As a dispersed source of the insulating resin for the part, the prepreg layer formed by previously containing the insulating resin is disposed on both sides of the base material layer, and the insulating resin contained in the prepreg layer has a low melting point. Arrange each prepreg layer so that it sequentially melts and flows out along the unmelted prepreg layer at the high melting temperature part from the center side of the laminated material at a temperature, and appropriately provide a passage for the molten resin penetrating the base material layer and each prepreg layer. Thereby, the outflow amount of the molten resin is adjusted and the molten resin is reliably guided to a required position.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of both a wire coil and a laminated material in a stator coil of a high-pressure rotating machine according to a first embodiment of the present invention corresponding to claims 1 and 2, and FIG. FIG. 3 is a sectional view of a laminated material according to a second embodiment of the present invention corresponding to the first and third aspects, and FIG. 3 is a characteristic diagram of a residual breakdown voltage with respect to a heat cycle of a stator coil of a high-pressure rotating machine.

First, in FIG. 1, FIG. 1 (a) is a sectional view of a wire coil 2 constituting a stator coil of a high-voltage rotating machine. Here, the arrangement position and the like of the laminated material 7 with respect to the wire insulated wire 4 are the same as in the conventional case illustrated in FIG. 4B, and the formation into the wire coil is performed by the same high-temperature press molding. Note that the wire insulated wire 4 does not show the wire insulating layer applied to the wire conductor.

FIG. 1 (b) illustrates a cross-sectional structure of the laminated material 7. As a plurality of prepreg layers having different resin melting temperatures, a prepreg layer 7a and a prepreg layer 7b are used.
2 illustrates an example in which both layers are arranged.

Here, the melting temperature of the contained resin is adjusted so that the prepreg layer 7a is higher than the prepreg layer 7b. The prepreg layer 7b to be higher,
They are arranged in the same layer 7a. For example, the prepreg layer 7a has a melting point of about 90 ° C. to 110 ° C., and the prepreg layer 7b has a melting point of about 60 ° C. to 80 ° C.

Therefore, during the high-temperature press molding of the wire coil, the molten resin from the prepreg layer 7b is hindered by the prepreg layer 7a forming the outer layer, and the length direction and the vertical direction of the coil formed by each wire insulated wire. Therefore, the state of the molten resin diffusion state can be more accurately estimated.
In addition, it is not necessary to hurry the curing of the molten resin by appropriately adjusting the fluidity of the molten resin by adjusting the melting temperature of the contained resin and the heating state, and the microencapsulated latent curing accelerator or a metal with low reactivity can be eliminated. Use of a salt hardening accelerator becomes possible, and resin foaming accompanying a rapid hardening reaction is prevented.

The prepreg layer is formed by mixing an epoxy solid type resin and a liquid type resin via a solvent and applying the mixture to the base layer. The melting temperature of the prepreg layer-containing resin is as follows. It is adjusted by changing the mixing ratio between the solid type having a high melting point and the liquid type having a low melting point in the epoxy resin.

The base material layer 7c is located at the center of the laminated material 7 and bears its strength. A laminated plate obtained by penetrating and curing an epoxy resin or the like into a glass cloth, a peeled mica sheet, an aromatic polyamide nonwoven fabric Formed from a heat calender sheet or the like.

Next, in the cross-sectional view of the laminated material shown in FIG. 2, FIG. 2A is formed by appropriately arranging through-holes forming a passage of the molten resin in the laminated material 7 exemplified in FIG. 1B. It is a perspective view which shows the external appearance of the laminated material 8 which was performed.

FIG. 2 (b) illustrates a cross-sectional configuration of the laminated material 8. The laminated material 8 is melted by penetrating through both the prepreg layers 8a and 8b and the base material layer 8c having different resin melting temperatures. A state in which an adjusting portion 8d forming a resin passage is provided is illustrated.

Here, an appropriate number of adjusting portions 8d are provided at appropriate positions corresponding to the arrangement positions of the respective wires constituting the wire coil, having an appropriate area and an appropriate number. Although there are various arrangement states including a shape arrangement, the illustrated case is an example in which a circular through hole is provided.

FIG. 3 is a characteristic diagram of the residual breakdown voltage of the stator coil of the high-voltage rotating machine according to the present invention. The horizontal axis indicates the number of heat cycles (times) applied to the stator coil, and the vertical axis indicates the residual breakdown. Indicates the voltage (%).

A characteristic line LA indicated by a circle is that of the coil according to the first embodiment of the present invention shown in FIG. 1, and a characteristic line LB indicated by a triangular mark is a second embodiment of the present invention shown in FIG. And a characteristic line L indicated by a square in the drawing.
C is for the prior art coil shown in FIG.

As shown in the drawing, the residual breakdown voltage of the conventional coil rapidly decreases with an increase in the number of heat cycles, but the residual breakdown voltage of the two coils according to the present invention is hardly reduced. Maintains characteristics.

[0033]

According to the present invention, an insulated wire in which an insulated wire is applied to a wire conductor is wound a plurality of times, and an insulating laminated material is disposed as an intermediate partition between the adjacent wire wires. The formed wire insulated wire bundle is subjected to high-temperature and pressure molding to form a wire coil, and this wire coil is provided with a resin-impregnated main insulating layer, which is impregnated with a thermosetting resin, and heat-cured to form the wire. Regarding the stator coil of the high-pressure rotating machine described above, 1) As described in the first aspect of the present invention, the laminated material is provided with a plurality of prepreg layers formed by previously containing resins used having different melting temperatures. And 2) by arranging the plurality of prepreg layers provided on the laminated material such that the resin melting temperature thereof is sequentially increased toward the outside centering on the base material layer, according to the invention of claim 2, Height of the wire coil During pressure molding, the molten resin from the inner prepreg layer having a lower resin melting temperature is hindered by the prepreg layer having a higher resin melting temperature which forms the outer layer, and the length direction and the vertical direction of the coil formed by each element insulated wire are reduced. With the prior art, the flow direction and fluidity of the molten resin were uncertain due to the fact that the flow direction and the flowability of the molten resin were uncertain due to the fact that the flow of the molten resin was adjusted and the molten prepreg layer-containing resin having the adjusted melting temperature was allowed to flow. The required amount of resin is smaller than in the case, and it is not necessary to hurry the curing of the molten resin, so that it is possible to use a curing accelerator having low reactivity, and the self-heating of the cured resin as in the case of the prior art is possible. It is possible to prevent the generation of voids due to foaming due to a rapid curing reaction.

In addition, sufficient resin filling into the required resin filling portion where the corners of the insulated wires are abutted by adjusting the fluidity of the molten resin including adjusting the melting temperature of the resin containing the prepreg layer and adjusting the heating time. It is possible to prevent the generation of voids due to unfilled resin and to secure the adhesive force between the individual wires constituting the wire coil, and to provide a laminated material as an intermediate partition between the wires. In combination with the use of the wire, it is possible to prevent the occurrence of wire misalignment due to wire collapse during wire coil high-temperature pressing. Further, 3) each of the element wires of the element coil is provided with a through-hole having an appropriate area which penetrates the base material layer and each of the prepreg layers and forms a passage for the molten resin. By providing an appropriate number at an appropriate position corresponding to the position of the electric wire,
It is possible to accurately fill an appropriate amount of resin into a required resin-filled portion that changes depending on the size of the wire.

That is, according to the present invention, it is possible to avoid both the generation of voids in the impregnated resin around each of the insulated wires constituting the wire coil and the occurrence of misalignment between the wires. It is possible to improve the safety of rotating machine operation by maintaining the insulation performance of the stator coil of the high-pressure rotating machine, reduce the required amount of insulating resin, and repair and clean up work due to excessive outflow of insulating resin. And the number of man-hours for manufacturing the stator coil can be reduced.

[Brief description of the drawings]

FIG. 1 shows a wire coil and a laminated material in a stator coil of a high-pressure rotating machine according to a first embodiment of the present invention,
(A) is a cross-sectional view of a wire coil, and (b) is a cross-sectional view of a laminated material.

FIG. 2 shows a laminate according to a second embodiment of the present invention;
(A) is a perspective view showing an appearance of a laminated material, and (b) is a cross-sectional view of the laminated material.

FIG. 3 is a characteristic diagram of residual breakdown voltage of a stator coil of a high-voltage rotating machine.

FIG. 4 shows a stator coil portion of a high-pressure rotating machine showing an embodiment of the prior art, wherein (a) is a cross-sectional view of a stator stator coil,
(B) is a cross-sectional view of the wire coil

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator coil 2 Element coil 3 Main insulation layer 4 Element insulated wire 5 Interlayer insulation 6 Laminated material 7 Laminated material 7a Prepreg layer 7b Prepreg layer 7c Base layer 8 Laminated material 8a Prepreg layer 8b Prepreg layer 8c Base layer 8d Adjustment unit

Claims (3)

[Claims] 1. A wire insulated wire having a wire conductor insulated by a wire is wound a plurality of times, and an insulating laminated material is provided between adjacent wire wires in a longitudinal direction of a winding slot. The wire insulated wire bundle arranged and formed as an intermediate partition is subjected to high-temperature press molding to form a wire coil, and the resin-impregnated coil formed by providing the resin-impregnated main insulating layer on the wire coil is subjected to heat. In a stator coil of a high-pressure rotating machine formed by impregnating a curable resin and heat-curing the same, the laminated material includes a plurality of prepreg layers formed by previously containing resins used at different melting temperatures. A stator coil for a high-pressure rotating machine, comprising: 2. The stator coil according to claim 1, wherein the plurality of prepreg layers provided on the laminated material are:
A stator coil for a high-pressure rotating machine, wherein the stator coil is arranged so that the resin melting temperature thereof is sequentially increased toward both outer sides of a base material layer of the laminated material. 3. A stator coil according to claim 1, wherein said laminated material penetrates through said base material layer and each prepreg layer to form a through-hole having an appropriate area to form a passage for molten resin. A stator coil of a high-voltage rotating machine characterized in that an appropriate number of the coils are provided at appropriate positions corresponding to the arrangement positions of the respective wires constituting the wire coil.