JPH09308159A - Stator coil of rotating electric machine - Google Patents

Abstract

(57) [Abstract] [Problem] Preventing minute cracks and peeling from occurring in the main insulating layer against ground due to thermal stress associated with temperature changes during resin impregnation / heat curing and during operation, and to prevent corona discharge. To obtain a fixed coil of a rotating electric machine having a structure capable of preventing generation as much as possible. SOLUTION: As a surface corona preventive layer 26, a releasable semiconductive layer 27 in which one surface on the main insulating layer 25 side is surface-treated.
And, a semiconductive layer 28 for protecting the releasable semiconductive layer 27 is provided on the outer periphery thereof. In addition, the releasable semiconductive layer 27 and the semiconductive layer 2
8 is formed into a tape and wound in opposite directions. Further, a surface corona preventive layer in the vicinity of the slot exit is provided on the releasable semiconductive layer, the releasable insulating layer provided on the outer periphery of the releasable semiconductive layer, and the outer periphery of the releasable insulating layer. And a semiconductive layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator coil of a high-voltage rotating electric machine manufactured by a total impregnation method in which resin is impregnated while the coil is housed in an iron core slot.

[0002]

2. Description of the Related Art As a resin impregnation method for a stator and a rotor coil of a high-voltage rotating electric machine, there are a single impregnation method in which resin is impregnated by a coil alone, and a total impregnation method in which resin is impregnated while the coil is housed in an iron core slot. is there. In this full impregnation method, the iron core and the coil are integrally fixed, and the voids in the iron core slot are filled with the resin, so the thermal conductivity between the coil and the iron core is high, and the cooling performance is excellent, and the resin impregnation, It has the advantage of simplifying the heating and curing process and is widely used as a resin impregnation method for the stator and rotor coil of a high-voltage rotating electric machine.

However, due to temperature changes during resin impregnation and heat curing, and temperature changes due to starting and stopping during operation, the thermal expansion coefficient of the mutual expansion between the inner wall surface of the core slot and the coil insulation is integrated. It is feared that the thermal stress resulting from the difference may cause cracking or peeling in the ground main insulating layer.

As a structure of a stator coil for preventing this, there is one disclosed in Japanese Patent Laid-Open No. 58-64005. FIG. 6 is a sectional configuration diagram showing this stator coil. In the figure, 1 is a coil conductor, 2 is wire insulation, 3
Is a ground insulating layer, 4 is a low resistance insulating layer, 5 is a releasable low resistance insulating layer, 6 is an iron core, 7 is a slot, and 8 is a wedge. A plurality of the coil conductors 1 each covered with the wire insulation 2 are bundled and the outside is covered with the ground insulating layer 3. On the outside of the ground insulating layer 3, a low resistance insulating layer 4 made of a conductive insulating tape or sheet is formed, and a releasable low resistance insulating layer 5 is further formed. The coil conductor 1 covered with each insulating layer as described above is housed in the slot 7 of the iron core 6 via the releasable low-resistance insulating layer 5, and after the wedge 8 is inserted so as to cover the opening of the slot 7. , The whole iron core is put in a resin impregnation tank for resin impregnation.

In the above stator coil, the low resistance insulating layer 4 and the releasable low resistance insulating layer 5 form a surface corona preventive layer around the ground insulating layer 3. Releasability Low-resistivity insulating layer 5 shows releasability to resin, so resin impregnation
Even if the coil conductor 1 or the like expands or contracts due to a change in heat or a temperature change due to start / stop during operation, the expansion or contraction is absorbed by the slippage on the outer surface of the releasable low-resistance insulating layer 5. In this way, the thermal stress acting between the stator coil and the iron core can be relaxed and the generation of surface corona can be suppressed.

FIG. 7 shows what is disclosed in Japanese Examined Patent Publication No. 7-44798. In this stator coil, as shown in the figure, the conductor device 16 is surrounded by the insulating layer 17, and the first semiconductor layer 18 / separation layer 19 / second semiconductor layer is provided on the outer periphery of the insulating layer 17 as a surface corona prevention layer. 20 are provided. In this structure, since the isolation layer 19 reduces the adhesion of the first and second semiconductor layers 18 and 20, stress-induced cracks occur in the isolation layer 19 and not in the insulating layer 17. In this way, corona discharge is prevented.

[0007]

In the stator coil of the conventional rotating electric machine as described above, the releasable low resistance insulating layer 5 is wound around the outermost peripheral surface of the ground insulating layer 3 as a surface corona preventing layer. . The releasable low-resistance insulating layer 5 is made of a thin film material and has low strength. Therefore, when the stator coil is inserted into the iron core slot during manufacturing, or when the coil expands or contracts during operation, the releasable low resistance insulating layer 5 is caught by the irregularities of the iron core 6 and the releasable low resistance insulating layer. 5 may be torn, which may impair the function of controlling the crack occurrence site. It is difficult to adjust the strength of the releasable low-resistance insulating layer 5 in consideration of the material and the shape. When the releasable low-resistive insulating layer 5 is torn and the adhered portions are reduced, the reliable releasability is difficult to be exhibited. There was a problem. Further, in the case where three layers are provided, it is not possible to specify whether peeling occurs between the first semiconductor layer 18 and the separation layer 19 or peeling occurs between the separation layer 19 and the second semiconductor layer 20, and it is possible to control the peeled portion. It was difficult. Furthermore, it also violates the requirement to make the thickness as thin as possible.

The present invention has been made in order to solve the above-mentioned conventional problems, and prevents damage to the releasable semiconductive layer while making the surface corona prevention layer as thin as possible.
It is configured to improve the slip between the surface corona preventive layer and the iron core slot to prevent the surface corona discharge from occurring more reliably and to cause peeling between specific layers to prevent peeling or cracks in the ground insulating layer. It is an object of the present invention to obtain a stator coil of a rotating electric machine that prevents corona discharge from being deteriorated due to the occurrence of electric discharge and has excellent characteristics in the long term.

[0009]

According to a first aspect of the present invention, there is provided a stator coil for a rotating electric machine, comprising: a conductor arranged in an iron core slot; a ground main insulating layer provided around the conductor; In a stator coil of a rotating electric machine comprising a surface corona preventive layer provided around the insulating layer and having a thermosetting resin for fixing the entire surface, the surface corona preventive layer is bonded to the ground main insulating layer side. It is characterized in that it is composed of a releasable semiconductive layer having a surface-treated portion on its surface, and a semiconductive layer provided on the outer periphery of the releasable semiconductive layer.

In the stator coil of the rotating electric machine according to the second structure of the present invention, in the first structure, the releasable semiconductive layer and the semiconductive layer are each formed by winding a tape,
The semiconductive layer is characterized by being wound in a direction opposite to the winding direction of the releasable semiconductive layer.

In the stator coil of the rotating electric machine according to the third structure of the present invention, the surface corona preventive layer is bonded to the ground main insulating layer side in the vicinity of both ends of the iron core slot of the first structure. A releasable semiconductive layer having a surface treatment portion on its surface,
It is characterized in that it is composed of a releasable insulating layer provided on the outer periphery of the releasable semiconductive layer and a semiconductive layer provided on the outer periphery of the releasable insulating layer.

Further, in the stator coil of the rotating electric machine according to the fourth structure of the present invention, the releasable semiconductive layer and the releasable insulating layer of the third structure are each formed by winding a tape, The releasable insulating layer is characterized by being wound in a direction opposite to the winding direction of the releasable semiconductive layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. 1 is a configuration diagram showing a part of a stator coil of a rotary electric machine according to a first embodiment of the present invention. In the figure, a stator coil 23 made of an insulated conductor is housed in a slot 22 formed in an iron core 21. The stator coil 23 includes a coil conductor 24, a ground main insulating layer 25 formed on the outside of the coil conductor 24, and a surface corona preventive layer 26 formed on the outside thereof. Surface corona prevention layer 26
Is composed of, for example, a releasable semiconductive layer 27 made of a tape made of a fluorine compound and a semiconductive layer 28 made of glass tape or polyester tape and conductive particles. Here, the iron core 21 and the stator coil 23 are integrally impregnated with a thermosetting impregnating resin by a total impregnation method, and the withstand voltage performance is imparted to the ground main insulating layer 25 and the surface corona prevention layer 26, and the thermal conductivity is also provided. A stator of a rotating electric machine having a superior stator coil is formed.

The releasable semiconductive layer 27 has releasability with respect to the resin to be impregnated, and FIG. 2 is a perspective view showing the releasable semiconductive layer 27 according to this embodiment. . The releasable semiconductive layer 27 is composed of a semiconductive material 27a formed by tape-forming polytetrafluoroethylene, which is made semiconductive with an additive such as carbon. Further, in order to eliminate the poor adhesion between the releasable semiconductive layer 27 and the ground main insulating layer 25, a surface treatment such as roughening the surface of the semiconductive material 27a on the ground main insulating layer 25 side by corona treatment or the like. Is applied to form an adhesion treated surface 27b, and the ground main insulating layer 2
Adhesion with 5 is improved. The main surface insulating layer 25 and the releasable semiconductive layer 27 are firmly adhered to each other by the adhesion-treated surface 27b, and the main surface insulating layer 25 and the surface corona preventive layer 26
The effect of preventing peeling at the interface with is obtained.

Further, in this embodiment, the releasable semiconductive layer 2 is
The ground main insulating layer 25 and the iron core 21 are fixed to each other by a resin via the semiconductor 7 and the semiconductive layer 28 formed on the outer peripheral surface thereof. Therefore, even if thermal stress acts between the ground main insulating layer 25 and the iron core 21, it is between the releasable semiconductive layers 27 and 28 or the releasable semiconductive layer. Sliding between 27 and the resin, the thermal stress applied to the main ground insulating layer 25 is relieved. Therefore, peeling or cracking does not occur inside the ground main insulating layer 25 or between the ground main insulating layer 25 and the releasable semiconductive layer 27, and the stator coil 23 and the iron core 21 are electrically connected. Generation of surface corona due to

By forming the semiconductive layer 28 on the outer side of the semiconductive layer 28 and the releasable semiconductive layer 27 constituting the surface corona preventive layer 26, the semiconductive layer 28 becomes releasable semiconductive. It acts to protect the layer 27. That is, the semiconductive layer 28 is made of a material having higher strength than the releasable semiconductive layer 27, and the stator coil 23 slides during insertion of the stator coil 23 into the iron core slot 22 during manufacturing or during operation. At this time, the releasable semiconductive layer 27 is protected from being caught and broken by the unevenness of the iron core 21. Therefore, the surface corona preventive layer 26 having a long life and high reliability can be obtained.

FIG. 3 is a vertical sectional view showing the surface corona preventing layer 26 of the stator coil according to this embodiment. As shown in the figure, the surface corona prevention layer 26 covering the outside of the main ground insulating layer 25 is formed on the releasable semiconductive layer 27 formed on the surface of the main ground insulating layer 25 and further outside thereof. It is composed of the semiconductive layer 28. The releasable semiconductive layer 27 and the semiconductive layer 28 constituting the surface corona prevention layer 26 are both formed of, for example, a tape having a thickness of about several tens of μm. The semi-conductive tape 27 is wound in a direction opposite to the winding direction. That is, if the releasable semiconductive tape 27 is wound clockwise around the ground main insulating layer 25, the semiconductive tape 28 is wound counterclockwise around the releasable semiconductive tape 27. Configure.

By winding the semiconductive tape 28 in the opposite direction to the release semiconductive tape 27 as described above, a tape between the release semiconductive tape 27 and the semiconductive tape 28 is formed. Considering the ends, the tapes are overlapped so as to intersect at one place during one round, so that the tape ends are less likely to be caught by each other and the coil slides well. Therefore, it is possible to prevent the occurrence of minute cracks and peeling at the interface between the main ground insulating layer 25 and the surface corona prevention layer 26, and it is possible to prevent corona discharge from occurring satisfactorily, so that the deterioration of the insulating layer of the stator coil is prevented. Can be prevented.

Embodiment 2. FIG. 4 is a sectional configuration diagram showing a surface corona prevention layer portion related to a stator coil of a rotary electric machine according to Embodiment 2 of the present invention. In the surface corona preventive layer portion of the stator coil according to the present embodiment, the configuration of the surface corona preventive layer 26 in the vicinity of the slot outlet 31, for example, within a range of about 150 mm from the slot outlet B is used as the releasable semiconductive layer 27, Type insulating layer 29, semiconductive layer 28 3
Slot central part 3 composed of layers and including slot central point A
0, the releasable semiconductive layer 27 is the same as in the first embodiment.
And a semiconductive layer 28.

FIG. 5 shows the ground main insulating layer 2 in the slot 22.
It is a characteristic view of the shear stress acting on No. 5. In the figure, the horizontal axis shows the position of the insulating layer in the slot from the center point A to the slot outlet B, and the vertical axis shows the shear stress acting on the insulating layer. The vertical axis has a value showing the peak of shear stress as 1.0. As shown in the figure, the shear stress acting on the coil insulating layer is measured from the central point A in the slot 22 to the vicinity of the slot outlet 3
It becomes larger as it approaches 1, and the largest shear stress acts at the slot outlet B.

Therefore, from the slot outlet B to the slot central portion 30, at least 1 / th of the peak value of the shear stress.
A part having a shear stress of 2 or more, in this case, at least a part 20 mm from the slot exit B is used as the releasing semiconductive layer 2
7, a releasable insulating layer 29, and a semiconductive layer 28.
It has a structure with good releasability. The releasable semiconductive layer 2 is formed by improving the releasability of the portion to which the shear stress is strongly applied.
7 and the releasable insulating layer 29, or the releasable insulating layer 2
9 is easily peeled off at the interface between the semiconductive layer 28 and the semiconductive layer 28, and almost no shear stress is applied to the ground main insulating layer 25, so that the coil can slide better in the slot 22 than in the slot central portion 30. . Therefore, the deterioration of the insulating layer can be effectively prevented, and the heat cycle resistance of the stator coil can be improved. Although the releasable insulating layer 29 is non-conductive in the present embodiment, since the coil insulating layer and the iron core slot are electrically connected at the slot central portion 30, corona discharge is also generated. It can be well prevented.

As the structure of the surface corona preventive layer 26 in the vicinity of the slot outlet 31, the releasable semiconductive layer 27 formed outside the ground main insulating layer 25 is, for example, corona treated on the surface on the ground main insulating layer 25 side. A sheet of a conductive fluorine compound whose roughness is improved by using a conductive fluorine compound is used, and the releasable insulating layer 29 formed on the outer side of the sheet is, for example, a tape of a nonconductive fluorine compound butted to the conductive fluorine compound. The tape 27 is wound in a direction opposite to the winding direction. That is, assuming that the releasable semi-conductive tape 27 is wound clockwise around the ground main insulating layer 25, the releasable insulating tape 29.
Is wound around the releasable semi-conductive tape 27 in the counterclockwise direction.

Considering the tape end between the releasable semiconducting layer 27 and the releasable insulating layer 29 by winding in the opposite direction in this way, one cross is made at one place during one round. As they overlap with each other, the tape ends are less likely to be caught by each other and the coil slides well. Therefore, it is possible to prevent fine cracks and peeling from occurring in the ground main insulating layer 25 or at the interface between the ground main insulating layer 25 and the surface corona prevention layer 26, and it is possible to favorably generate corona discharge. It is possible to prevent deterioration of the insulating layer.

[0024]

As described above, according to the first configuration of the present invention, the conductor arranged in the iron core slot, the main earth insulating layer provided around the conductor, and the main earth insulating layer are provided around the conductor. In a stator coil of a rotating electric machine, which comprises a surface corona preventive layer provided, and which has a thermosetting resin for fixing the entire surface, the surface corona preventive layer has a surface treatment part on the surface to be adhered to the ground main insulating layer side. By having a releasable semiconductive layer having, and a semiconductive layer provided on the outer periphery of the releasable semiconductive layer, the coil insulating layer and the iron core are electrically connected. In addition to preventing surface corona,
While the ground-main insulating layer and the releasable semi-conductive layer are firmly adhered by the impregnating resin, the release semi-conductive layer and the semi-conductive layer are easily peeled off, and the inside of the ground-main insulating layer and the ground It is possible to prevent corona generation due to peeling and cracks at the interface between the insulating layer and the releasable semi-conductive layer, and to effectively prevent deterioration of the main insulating layer to ground due to corona discharge, and excellent heat cycle resistance. There is an effect that the stator coil of the rotating electric machine can be obtained.

According to the second structure of the present invention, the first
In the configuration, the releasable semiconductive layer and the semiconductive layer are each formed by winding a tape, and the semiconductive layer is wound in a direction opposite to the winding direction of the release semiconductive layer, There is an effect that it is possible to obtain a stator coil of a rotary electric machine that prevents a catch between the releasable semiconductive layer and the semiconductive layer and allows the coil to slide well.

According to the third aspect of the present invention, the first
In the vicinity of both ends of the core slot of the constitution, the surface corona preventive layer has a releasable semiconductive layer having a surface treatment part on the surface to be adhered to the ground main insulating layer side, and an outer periphery of the releasable semiconductive layer By comprising the releasable insulating layer provided and the semi-conductive layer provided on the outer periphery of the releasable insulating layer, it is possible to almost eliminate the shear stress acting on the coil insulating layer, and in the iron core slot. There is an effect that a stator coil of a rotating electric machine having good sliding of the coil can be obtained.

According to the fourth aspect of the present invention, the third configuration
The releasable semi-conductive layer and the releasable insulating layer having the above structure are each formed by winding a tape, and the releasable insulating layer is wound in a direction opposite to the winding direction of the releasable semi-conductive layer. As a result, there is an effect that a stator coil of a rotating electric machine can be obtained in which a catch is prevented between the releasable semiconductive layer and the releasable insulating layer, and the coil can slide well.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a part of a stator coil of a rotary electric machine according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a releasable semiconductive layer according to the first embodiment.

FIG. 3 is a vertical cross-sectional view showing a surface corona preventive layer portion of the stator coil according to the first embodiment.

FIG. 4 is a sectional configuration diagram showing a surface corona prevention layer portion of a stator coil according to a second embodiment of the present invention.

FIG. 5 is a characteristic diagram showing shear stress acting on a ground main insulating layer in an iron core slot according to the second embodiment.

FIG. 6 is a cross-sectional configuration diagram showing an example of a conventional stator coil.

FIG. 7 is a configuration diagram showing another example of a conventional stator coil.

[Explanation of symbols]

21 cores, 22 slots, 23 stator coils, 2
4 conductors, 25 ground insulating layer, 26 surface corona preventive layer, 27 releasable semi-conductive layer, 28 semi-conductive layer, 29 releasable insulating layer, 30 slot central part, 31 slot exit vicinity part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Takada 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (4)

[Claims] 1. A conductor arranged in an iron core slot, a ground main insulating layer provided around the conductor, and a surface corona preventive layer provided around the ground main insulating layer. In a stator coil of a rotating electric machine provided with a thermosetting resin to be fixed, the surface corona preventive layer includes a releasable semiconductive layer having a surface treatment portion on a surface to be bonded to the ground main insulating layer side, A stator coil for a rotating electric machine, comprising a semiconductive layer provided on the outer periphery of a patternable semiconductive layer. 2. The releasable semiconductive layer and the semiconductive layer,
2. A stator coil for a rotating electric machine according to claim 1, wherein the stator coil is formed by winding a tape, and the semiconductive layer is wound in a direction opposite to a winding direction of the releasable semiconductive layer. . 3. A releasable semiconductive layer having a surface treatment portion on a surface to be bonded to the ground main insulating layer side, in the vicinity of both ends of the iron core slot, and the releasability. The fixing of a rotating electric machine according to claim 1, wherein the fixing electric machine comprises a releasable insulating layer provided on the outer periphery of the semiconductive layer and a semiconductive layer provided on the outer periphery of the releasable insulating layer. Child coil. 4. The releasable semiconductive layer and the releasable insulating layer are each formed by winding a tape, and the releasable insulating layer has a winding direction of the releasable semiconductive layer. The stator coil of the rotating electric machine according to claim 3, wherein the stator coil is wound in the opposite direction.