JPH09149578A - High pressure rotating machine coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure rotating machine coil equipped with an outer corona preventive layer which prevents the mechanical damage of an insulating layer by relaxing the thermal stress of the insulating layer to ground of a stator insulating coil caused by heat cycle, in the stator insulating coil of the high pressure rotating machine coil united by the impregnated resin by full impregnation method. SOLUTION: This coil is provided with an outer corona preventive layer being made by winding a composite tape 11, which is constituted by sticking together the stress relaxing layer 13 consisting of a stripping mica having a tape width half or under the width of a semiconductive tape 12, according to the end face on one side of the width of the semiconductive tape 12, around the insulating layer to ground of a stator insulating coil 8, laying them on top of the other so that the face of the semiconductive tape 12 may cover both sides of a stress relaxing layer 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to insulation of a large-sized high-voltage rotating machine coil obtained by fully impregnating an impregnating resin into a stator insulating coil having an outer corona preventing layer housed in an iron core slot of a high-pressure rotating machine. Regarding configuration.

[0002]

2. Description of the Related Art FIGS. 9 and 10 show a conventional stator insulating coil of a high-voltage rotating machine. FIG. 9 is a sectional view of the stator insulating coil inserted in a stator core, and FIG. X-X
It is a principal part sectional view of the stator insulation coil corresponding to an arrow view in the length direction. As a method of manufacturing an insulating coil for a rotating machine, there is a full impregnation insulation method in which the insulating coil is housed in an iron core slot, and the insulating coil and the iron core are integrally impregnated with resin and cured.
In this full impregnation insulation method, as shown in FIG. 9, first, a wire conductor that has been subjected to wire insulation is wound a plurality of times to produce a wire conductor bundle 1, and the wire conductor bundle 1 is arranged in the longitudinal direction. Mica foil with excellent electric field resistance is fired or crushed by high-pressure water current to form fine scales, and then laminated mica is made. The laminated mica insulating tape is wound to form the ground insulating layer 2. Then, in order to prevent occurrence of partial discharge (corona discharge) due to poor electrical contact between the ground insulating layer 2 and the iron core slot 4 of the stator core 3, a resistance value of several tens is provided on the outer periphery of the ground insulating layer 2. A semi-conductive low-resistance tape of KΩ is overlapped and wound in a range substantially the same as the iron core slot length to form the outer corona prevention layer 5. Then, an end corona preventive layer (not shown) is applied to the end of the external preventive corona preventive layer 5 to prepare an unimpregnated stator insulated coil 8 not impregnated with resin. Next, this non-impregnated stator insulating coil 8 is mounted in the iron core slot 4 together with auxiliary materials such as interphase insulation 6, wedge 7, etc., and after each stator insulating coil 8 is connected, it is installed in a resin impregnation tank. Then, the impregnated resin consisting of a thermosetting resin such as epoxy resin is integrally impregnated by vacuum and pressure, then taken out from the resin impregnation tank and cured in a heating and curing furnace to produce a resin-impregnated high-voltage rotating machine coil. .

In this method of manufacturing a high-voltage rotating machine coil by the full impregnation insulation method, since the resin is sufficiently impregnated inside the ground insulation layer 2, and between the outer corona prevention layer 5 and the iron core slot 4, a dense coil insulation layer is provided. Therefore, high reliability of insulation can be achieved, and the number of manufacturing processes can be reduced. Therefore, the insulating coil of the high-voltage rotating electric machine to which a high voltage is applied is applied from small machines to large machines. By the way, the heating temperature of the resin curing in the heating and curing furnace after the resin impregnation is performed at a high temperature close to the operating temperature so that the coil insulating layer can maintain sufficient insulation performance at the operating temperature of the rotating machine. Be seen. Therefore, when the impregnated resin is cooled to room temperature after being heated and cured, due to the difference in thermal expansion between the ground insulating layer 2 and the wire conductor bundle 1 and the stator core 3 which constitute the coil insulating layer impregnated with the resin and cured. , Mechanical stress is generated at the interface between the wire conductor bundle 1 and the ground insulating layer 2, and between the ground insulating layer 2 and the core slot 4 of the stator core 3, and between the interfaces and inside the ground insulating layer 2. Shear peeling may occur and voids may occur. Further, the above-mentioned voids generated in the interface between the wire conductor bundle 1 and the iron core slot 4 and in the ground insulating layer 2 are insulated from the ground by expansion and contraction of the wire conductor bundle 1 during the operation and stop of the rotating machine due to the heat cycle. It may also be caused by thermal stress applied to the layer 2.

A high voltage is applied to the ground insulating layer 2 at the voids formed at the interface and inside of the ground insulating layer 2 as described above, corona discharge is generated, and the ground insulating layer 2 is damaged and the stator. The insulation performance of the insulating coil 8 is deteriorated. The thermal stress generated in the ground insulating layer 2 that causes the generation of the voids becomes larger in the stator insulating coil 8 of a large rotating machine having a long coil length and a long iron core slot 4 length. Therefore, in order to relieve the thermal stress generated in the ground insulating layer 2 of the stator insulating coil of the large-sized rotating machine, the outer corona preventing layer 5 of FIG.
And a structure in which a semiconductive layer having a sliding property is provided between the core core 4 and the core slot 4 of the stator core 3 and the semiconductive layer is slid between the outer corona prevention layer 5 and the structure shown in FIG.
As described in JP-A-44798, the outer corona preventive layer 5
It is permeable to the impregnated resin between it and the semiconductive layer 9 wound around the outer periphery of the resin, and does not prevent the external corona preventing layer 5 and the semiconductive layer 9 from being adhered by the resin. An external corona for preventing the generation of the above-described voids in the ground insulating layer 2 is provided by providing the separation layer 10 having a reduced adhesive strength to some extent and relaxing the stress generated in the ground insulating layer 2 in the separation layer 10. Preventive structure is adopted.

[0005]

By the way, as described above, the structure for relaxing the thermal stress generated in the ground insulating layer has the outer corona preventive layer and the iron core provided on the outer peripheral portion of the outer corona preventive layer. Sliding the interface with the semi-conductive layer that is in electrical contact with the slot relaxes the thermal stress caused by the difference in thermal expansion between the wire conductor bundle or stator core and the ground insulating layer. It is a method to do. Therefore, a tape or sheet newly provided with a semi-conductive layer for stress relaxation on the outer periphery of the outer corona preventive layer is wound around the outer corona preventive layer so as to be in conductive contact with the outer corona preventive layer, and the above Japanese Patent Publication No. 7-44798. As described above, since a structure in which a separation layer is further inserted between the external corona prevention layer and the semiconductive layer is adopted, the coil winding structure becomes complicated and more insulating coil winding work steps are required than before. However, there is a problem that it takes time to manufacture the stator insulating coil.

An object of the present invention is to provide a large-sized high-voltage rotating machine coil integrally impregnated with an impregnating resin, which is generated due to a heat cycle during cooling after heating and hardening the stator insulating coil and during heat cycle during operation. It is an object of the present invention to provide a high-voltage rotating machine coil provided with an external corona preventive layer, which has a simple insulating structure for relieving thermal stress of the insulating layer and which can be manufactured without changing the conventional winding work process.

[0007]

In order to solve the above-mentioned problems, the present invention provides a stator insulating coil in which a semi-conductive tape and a stress relaxation layer are provided on the outer periphery of the ground insulation which constitutes the stator insulating coil. The semi-conductive tape has an outer corona preventive layer formed by overlapping and winding so as to cover both sides of the stress relaxation layer. As a result, even in the coil structure of the high-voltage rotating machine, which is inserted into the iron core slot of the stator core, and the wire conductor bundle, the ground insulating layer and the iron core slot are integrally impregnated with a thermosetting resin, Expansion and contraction of the ground insulation layer due to mechanical thermal stress applied to the ground insulation layer due to the heat cycle during heating and cooling and operation, by absorbing by shearing and expanding and contracting the stress relaxation layer between the semiconductive tapes described above. It is possible to prevent the generation of voids due to the boundary surface between the ground insulating layer and the wire conductor bundle or the iron core slot, and peeling in the ground insulating layer. Further, in the present invention, even if a void is generated in the stress relaxation layer of the outer corona-preventing layer due to shearing and stretching, the void in the outer corona-preventing layer is electrically connected to the core slot of the stator core. Since it is positioned between the semi-conductive tapes of the composite tape forming the external corona preventive layer of equipotential with the iron core slots by making a physical contact, no potential difference is generated between the voids and the occurrence of corona discharge can be prevented. .

When the stress relaxation layer is made of peeled mica, the impregnated resin does not penetrate into the laminated scale-like mica foil layers constituting the peeled mica.
The expansion and contraction of the ground insulating layer can be absorbed by the shear peeling of the mica foil of the peeled mica described above.

Further, instead of the above-mentioned peeling mica, the stress relaxation layer is made of a semiconductive silicone compound, so that the expansion and contraction of the above-mentioned ground insulating layer is absorbed by the elastic deformation of the semiconductive silicone compound. be able to. Since it is also thermally stable, it is suitable for a high-voltage rotating machine coil that requires high-temperature characteristics during heat curing during resin impregnation and during heat cycle during operation.

In the composite tape constituting the above-mentioned outer corona preventive layer, a stress relaxation layer having a tape width less than half the width of the semiconductive tape is provided on one side of the semiconductive tape. By using the ones with the side end faces of the composite tape laminated together, the composite tape is not provided with a stress relaxation layer in the length direction of the outer periphery of the ground insulating layer. By winding while overlapping, an external corona preventive layer having a semiconductive tape on both sides of the stress relaxation layer can be formed.

Further, the composite tape forming the outer corona preventive layer is formed by covering both sides of the stress relaxation layer with the semiconductive tape, so that the both sides of the stress relaxation layer are semiconductive as described above. An external corona-preventing layer having a tape can be configured, and the stress relaxation layer does not peel off from the semi-conductive tape surface during winding, or the winding workability is hindered by adhesion between composite tapes. can do.

If the semi-conductive tape constituting the composite tape is made of semi-conductive non-woven fabric or woven cloth, the impregnating resin has a good resin impregnating property and is excellent in high electric field characteristics. A ground insulation layer of a stator insulation coil of a high-voltage rotating machine is obtained.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is a sectional view of essential parts of a stator insulating coil of a high-voltage rotating machine coil according to a first embodiment of the present invention. FIG.
The stator coil insulation 8 shown in (1) corresponds to the conventional one shown in FIG. 10, and the external corona preventive layer is shown in an enlarged manner.
The composite tape 11 forming the outer corona prevention layer 5a
Is a semi-conductive tape 12 made of a semi-conductive fleece obtained by treating a non-woven fabric made of polyester fleece with carbon as shown in FIG. A stress relieving layer 13 made of a peeled mica layer having a tape width of 5 is attached to one side end face of the width of the semiconductive tape 12 so as to be bonded thereto. And this external corona prevention layer 5a
The composite tape 11 is wound so that the width of the composite tape 11 is half-lapped and wound once in the longitudinal direction so that the semiconductive tape 12 side is closely adhered to the outer peripheral surface of the ground insulating layer 2 of the stator insulating coil 8. Configure.

When the composite tape 11 is wound in a semi-lapped manner, the semi-conductive tape 1 without the stress relaxation layer 13 is provided.
The surface of 2a is overlapped and wound so as to cover the width of the stress relaxation layer 13. When the non-impregnated stator insulating coil 8 having the outer corona preventing layer 5a wound in this manner is inserted into the iron core slot 4 of the stator core 3 (FIG. 9), the ground insulating layer 2 side and the stator The semi-conductive tape 12 of the outer corona preventing layer 5a which is in contact with the iron core 3 side, respectively.
Is the same as the ground potential of the stator core 3. Therefore, even if mechanical stress is applied to the stator insulating coil 8 made of resin by full impregnation due to the heat cycle during the cooling after the resin is cured and during the operation as described above, the stress relaxation is performed as described above. Since the peeling mica layer of the layer 13 has a small shearing force, the above-mentioned stress can be relaxed by the sliding fracture of the peeling mica layer, and the shear fracture of the peeling mica layer forms a void portion in the stress relaxation layer 13. However, as described above, since the voids are located at the same potential, corona discharge does not occur and it is possible to prevent the insulation performance of the stator coil insulating layer 8 from deteriorating.

In the first embodiment of the present invention,
A semi-conductive fleece was used as the semi-conductive tape 12 constituting the composite tape 11 and a peeling mica layer was used as the stress relaxation layer 13, but the semi-conductive fleece including other embodiments described later is also included. As the tape 12, a glass cloth base material treated with a semi-conductive resin or a semi-conductive tape made of a semi-conductive woven fabric mixed with carbon fibers can be used to impregnate the ground insulating layer 2 with the resin. It can be used as it does not damage. Further, even if a semiconductive silicon compound is used as the stress relaxation layer 13, expansion and contraction of the ground insulating layer due to thermal stress can be elastically deformed and absorbed, so that it can be applied in place of the peeling mica layer described above. .

Embodiment 2 FIG. 3 is a cross-sectional view of essential parts of a stator insulating coil of a high-voltage rotating machine coil according to a second embodiment of the present invention. The difference from the first embodiment of the present invention is that, as shown in FIG. 4, the composite tape 11a forming the outer corona preventing layer 5b is used in the first embodiment, and the composite tape 11 of FIG. The semi-conductive tape 12b is also attached to one surface of the stress relieving layer 13, and when the winding is wound around the ground insulating layer 2, the peeling mica layer of the stress relieving layer 13 is a semi-conductive tape 12. It is because the one that prevents the composite tape 11 from being peeled off or the semiconductive silicone compound attached to the semiconductive tape 12 to make the winding workability of the composite tape 11 difficult is used. Also in the case of this composite tape 11a,
As in the case of the first embodiment, the semi-conductive tape 12a is wound so that the surface of the tape 12a overlaps the stress relaxation layer 13 and is half-overlapped to form the outer corona preventing layer 5b having the structure of FIG. . The external corona preventive layer 5b according to the second embodiment can also relax the mechanical stress by shearing or deforming the stress relaxation layer 13 when the mechanical stress is applied to the ground insulating layer 2 as described above. It is possible to prevent the occurrence of corona discharge even if the voids are formed.

Embodiment 3 FIG. 5 is a sectional view of the essential parts of a stator insulating coil of a high voltage rotating machine coil according to a third embodiment of the present invention. The external corona preventive layer 5c shown in FIG. 5 according to the third embodiment is a semiconductive fleece 12b bonded for protection of the stress relaxation layer 13 shown in FIG. 4 used in the second embodiment. Instead of the above, as shown in FIG. 6, a composite tape 11 having a structure in which the stress relaxation layer 13 and the semiconductive tape 12a are bonded together with a semiconductive tape 12c so as to cover both surfaces.
It is configured by using b. And this composite tape 11
b is wound with the semi-conductive tape portion 12c having no stress relaxation layer 13 superposed on the surface of the stress relaxation layer 13.
Therefore, the stator core side of the stress relaxation layer 13 of the outer corona prevention layer 5c has a three-layer structure of a semiconductive tape.

Fourth Embodiment FIG. 7 is a sectional view of a main part of a stator insulating coil of a high voltage rotating machine coil according to a fourth embodiment of the present invention. FIG.
The external corona preventive layer 5d shown in FIG. 8 is a composite tape 11c shown in FIG. 8 in which the stress relieving layer 13 is sandwiched between the semiconductive tapes 12 and 12 in order to protect the stress relieving layer 13. It is constructed by layering. In the structure of the fourth embodiment, the dimensional thickness of the outer corona preventive layer 5d is large, but the stress relaxation layer 13 is provided in two steps in the thickness direction of the ground insulating layer 2, so that the ground insulating layer is formed. Since the mechanical stress acting on 2 is relaxed by these stress relaxation layers 13, the stator insulating coil 8 can be made more reliable.

[0019]

As described above, in the present invention, the high voltage rotating machine coil is formed by using the composite tape of the semiconductive tape and the stress relaxation layer on the outer periphery of the ground insulating layer of the stator insulating coil, The semi-conductive tape side of this composite tape was provided with an external corona preventing layer formed by overlapping and winding so as to cover both sides of the stress relaxation layer. As a result, even in a high-voltage rotating machine coil in which a wire conductor bundle, a ground insulating layer, and an iron core slot formed by the full impregnation insulation method are integrated with a thermosetting resin, the ground insulating layer is formed by a heat cycle during coil manufacturing and operation. The expansion and contraction of the ground insulation layer due to the thermal stress applied to the core is absorbed by the shearing and expansion and contraction of the stress relaxation layer provided between the semi-conductive tapes, and the interface between the core slot and the ground insulation layer is fixed by peeling. It is possible to prevent mechanical damage to the child insulation coil.

Further, according to the present invention, even if a void portion is generated in the stress relaxation layer of the outer corona preventive layer due to shearing or the like, it is in electrical contact with the iron core slot of the stator core to have the same potential as the iron core slot. Since it is located between the semi-conductive tapes of the composite tape, a potential difference does not occur between the voids, and the occurrence of corona discharge can be prevented. Therefore,
By applying the external corona preventive layer of the present invention, it is possible to avoid the problem of mechanical stress to the ground insulating layer in the full impregnation insulation method. Even in the manufacture of stator insulated coils for large-capacity high-voltage large-sized rotating machines that use the impregnation method,
Since the full impregnation method can be applied, it is possible to significantly reduce the number of man-hours for manufacturing a high-voltage large-sized high-voltage rotary machine coil.

Moreover, since the composite tape has a structure in which a semiconductive tape and a stress relaxation layer are laminated, by winding the composite tape once while superposing it on the ground insulating layer of the stator insulating coil, As described above, since a corona prevention layer that can relieve the mechanical stress applied to the ground insulating layer and prevent insulation damage due to corona discharge can be obtained, a semi-conductive layer for stress relaxation is provided on the outer periphery of the outer corona prevention layer as in the conventional case. Since it does not require a complicated winding process of providing a separate layer between the external corona prevention layer and the semiconducting layer, the winding man-hour can be reduced and the external corona prevention layer for stress relaxation of the above-mentioned conventional structure can be provided. Since a stator insulating coil having an outer corona preventing layer having a small thickness can be obtained, it is possible to contribute to downsizing of the high-voltage rotating machine by reducing the coil insulating layer.

[Brief description of the drawings]

FIG. 1 is a sectional view of essential parts of a fixed insulator coil of a high-voltage rotating machine coil according to a first embodiment of the present invention.

2 is a partial perspective view of a composite tape forming an outer corona preventive layer of the high-voltage rotating machine coil of FIG. 1. FIG.

FIG. 3 is a cross-sectional view of essential parts of a stator insulating coil of a high voltage rotating machine coil according to a second embodiment of the present invention.

FIG. 4 is a partial perspective view of a composite tape forming an outer corona preventive layer of the high-voltage rotating machine coil of FIG.

FIG. 5 is a cross-sectional view of essential parts of a stator insulating coil of a high voltage rotating machine coil according to a third embodiment of the present invention.

6 is a partial perspective view of a composite tape forming an outer corona preventive layer of the high-voltage rotating machine coil of FIG.

FIG. 7 is a cross-sectional view of essential parts of a stator insulating coil of a high voltage rotating machine coil according to a fourth embodiment of the present invention.

8 is a partial perspective view of a composite tape forming an outer corona preventive layer of the high voltage rotating machine coil of FIG. 7. FIG.

FIG. 9 is a cross-sectional view of a stator insulating coil of a conventional high-voltage rotating machine.

10 is a cross-sectional view of essential parts in the length direction of the stator insulating coil corresponding to the view taken along the line XX of FIG.

[Explanation of symbols]

 1 Wire conductor bundle 2 Ground insulation layer 3 Stator core 4 Iron core slot 5 External corona prevention layer 5a External corona prevention layer 5b External corona prevention layer 5c External corona prevention layer 5d External corona prevention layer 8 Stator insulation coil 11 Composite tape 11a Composite tape 11b Composite tape 11c Composite tape 12 Semi-conductive tape 12a Semi-conductive tape 12b Semi-conductive tape 12c Semi-conductive tape 13 Stress relaxation layer

Claims (7)

[Claims] 1. A ground insulating layer made of unimpregnated mica tape wound a plurality of times on a wire conductor bundle, and a semiconductive low-resistance tape overlaid on the outer periphery of the ground insulating layer in the longitudinal direction. An unimpregnated insulated coil having an outer corona preventive layer formed by winding and an end corona preventive layer applied to the end of the outer corona preventive layer is housed in the iron core slot,
In this high-voltage rotating machine coil in which the unimpregnated insulating coil and the iron core are integrally impregnated with a thermosetting impregnating resin in an impregnation tank and then heat-cured in a curing furnace, the outer corona preventive layer is semiconductive. And a stress-relaxation layer, which are composite tapes, and the semi-conductive tape of the composite tape is formed by being superposed and wound so as to cover both sides of the stress-relaxation layer. Machine coil. 2. The high-voltage rotating machine coil according to claim 1, wherein the stress relieving layer of the composite tape forming the outer corona preventing layer is composed of peeled mica. 3. The high-voltage rotating machine coil according to claim 1, wherein the stress relieving layer of the composite tape constituting the outer corona-preventing layer is made of a semiconductive silicone compound. 4. The high-voltage rotating machine coil according to any one of claims 1 to 3, wherein the composite tape forming the outer corona-preventing layer has a semi-conductive tape having a width of the semi-conductive tape on one side thereof. A high-voltage rotating machine coil, wherein a stress relaxation layer having a tape width of half or less is superposed on one side end surface of the semiconductive tape width. 5. The high-voltage rotating machine coil according to any one of claims 1 to 4, wherein the composite tape forming the outer corona-preventing layer is provided with a semi-conductive tape on both sides of the stress relaxation layer. A high-voltage rotating machine coil characterized in that 6. A high-voltage rotating machine coil according to claim 1, wherein the semi-conductive tape forming the composite tape is made of a semi-conductive non-woven fabric. 7. A high-voltage rotating machine coil according to claim 1, wherein the semi-conductive tape forming the composite tape is made of a semi-conductive woven cloth. .