JPS63257428A - Winding of rotating electric machine - Google Patents

Abstract

PURPOSE:To improve insulating resistibility, by constituting the corona shield layer of insulating conductor enclosed in a slot of an iron core with semiconductive paint coated on the outside surface of heat-contractible film. CONSTITUTION:A stator winding 13 is constituted with an insulated conductor 12 enclosed in two steps, up and down, in a slot 11 of a stator iron core 10 of a motor. This insulated conductor 12 is composed of a conductor 14, an insulating layer 15 wound around with an insulating tape such as a mica tape, etc., an insulating layer 16 wound around with heat-contractible insulating tape and a corona shield layer 17. The corona shield layer 17 is composed of a sheet or film material coated with semiconductive paint 17b to the outside surface of synthetic resin film 17a as base material having heat resistibility. Thus, the occurrence of corona discharge between the insulating layer and the corona shield layer of the insulating conductor can be prevented and the insulating resistibility improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a winding of a rotating electrical machine housed in a slot of an iron core.

(Prior Art) FIG. 4 shows a conventional example of a stator winding of an electric motor, which is a rotating electric machine. That is, 1 is an insulated conductor, which is formed by applying an insulating layer 3 around the conductor 2 using mica tape or the like, and applying an insulating layer 4 around the insulating layer 3 using an insulating tape having heat shrinkability. Further, around this insulating layer 4, a corona shield layer 5 made of a tape made of a base material such as glass cloth or nonwoven fabric coated with semiconductive paint is applied. After this insulated conductor 1 is housed in the slots 7 of the stator core 6 in two stages, upper and lower, it is impregnated with epoxy resin by vacuum pressure impregnation treatment.

According to such a conventional configuration, the upper and lower insulated conductors 1.1
A substantially triangular gap 8 is created between the epoxy resin and the inner surface of the slot 7, and since this gap 8 is relatively large due to its structure, the epoxy resin is sufficiently filled into the gap 8 during the vacuum pressure impregnation process. There is a problem in that voids are likely to occur without contact and corona is generated between the slot 7 and the inner surface of the slot 7. For this reason, conventionally, as described above, the corona shield layer 5 is applied around the insulating layer 4 to make the corona shield layer 5 and the stator core 6 approximately at the same potential, thereby preventing corona generation in the gap 8. That's what I do.

(Problems to be Solved by the Invention) The stator core 6 is impregnated with an epoxy resin by vacuum pressure impregnation treatment and then heated and dried. During this drying process, the heat-shrinkable insulating layer 4 contracts and forms a tight seal with the insulating layer 3, but the corona shield layer 5, which is made of glass cloth or non-woven fabric as a base material, does not contract, and therefore, as shown in FIG. As shown in FIG. 2, a gap 9 is created between the corner of the insulating layer 4 and the corner of the corona shield layer 5. In this case, the corona shield layer 5 is at approximately the same potential as the stator core 6, and a voltage is applied between the corona shield layer 5 and the insulating layer 4, so corona discharge occurs in the gap 9. There is a problem that the insulation deteriorates and the insulation life is shortened.

The present invention has been made in view of the above circumstances, and its purpose is to prevent corona discharge from occurring between the insulating layer of the insulated conductor and the corona shield layer, and to improve the insulation properties. Provides electrical windings.

[Structure of the Invention] (Means for Solving the Problems) The winding of the rotating electrical machine of the present invention is an insulated conductor in which an insulating layer is provided around the conductor and a corona shield layer is provided around the insulating layer. It is characterized in that the corona shield layer is constructed by applying semiconductive paint to the outer surface of a heat-shrinkable film.

(Function) According to the winding wire for a rotating electric machine of the present invention, the corona shield layer based on a heat-shrinkable film shrinks due to heat when drying, and becomes densely layered with the insulating layer around the conductor. , there is no gap between the insulating layer around the conductor and the corona shield layer around it that would cause corona discharge.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

First, the configuration of the main parts will be described according to FIGS. 1 and 2. Reference numeral 10 designates a stator core of an electric motor, which is a rotating electrical machine, with an open slot 11. Inside the slot 11, an insulated conductor 12 is housed in two halves, an upper and a lower part, to form a stator winding 13, which is a winding. ing. And this insulated conductor 12
is structured as follows. That is, 14 is a conductor, around which an insulating layer 15 is applied by winding an insulating tape such as mica tape. Furthermore, a heat-shrinkable insulating tape (for example, the heat shrinkage rate is about 10% under heating conditions of 150° C. and 30 minutes) is placed around this insulating layer 15.
The insulating layer 16 is applied by winding. 1
7 is a corona shield layer that is wound around the insulating layer 16, and as shown in FIG. It is made of a sheet material or film material coated with a semiconductive paint 17b. In this case, in the corona shield layer 17, the thickness dimension of the film 17a is set to 0.03 to 0.05 arm, and the heat shrinkage rate of the film 17a is 150°C.

It is set to about 3 to 9% under heating conditions for 30 minutes, and the thickness dimension of the semiconductive paint 17b is 0.01 to 0.02aus.
The resistance value of the semiconductive paint 17b is set to 101 to 103 Ωcm. The stator winding 13, which has such an insulated conductor 12 accommodated in the slot 11 of the stator core 10, is impregnated with an epoxy resin by vacuum pressure impregnation treatment, and thereafter Stator core 1 with stator winding 13 wound around it
0 will be heated and dried. In this case, it is conventional that a substantially triangular gap 18 is formed between the upper and lower two-stage insulated conductors 12.12 housed in the slots 11 of the stator core 10 and the inner surface of the slots 11. However, since the semiconductive paint 17b of the corona shield layer 17 is in contact with the inner surface of the slot 11, the corona shield layer 17 and the stator core 10 are at approximately the same potential, and therefore,
Even if the gap 18 is not sufficiently filled with epoxy resin during the vacuum pressure impregnation process and voids are generated, this gap 1
Corona will not occur in the 8 parts. Note that 19 is a magnetic wedge attached to the opening of the slot 11.

According to this embodiment, the following effects can be obtained. That is, the corona shield layer 1 of the insulated conductor 12
7 to a heat-shrinkable film 17a and semiconductive paint 1.
tg by sheet material or film material coated with 7b.
Therefore, when the stator winding 13 is impregnated with epoxy resin by vacuum pressure impregnation treatment and then heated and dried,
The film 17a of the corona shield layer 17 is thermally shrunk and comes into close contact with the insulating layer 15. As a result, there is a gap 9 between the corona shield layer 17 and the insulating layer 15 as in the conventional case.
Therefore, it is possible to prevent corona discharge from occurring between the corona shield layer 17 and the insulating layer 15, and it is possible to improve the insulation properties.

FIG. 3 shows the experimental results of dielectric voltage grounding electric field strength characteristics, where the solid line curve t1 is for this example, and the broken line curve 2 is for this example.
is a conventional example. As is clear from FIG. 3, as the electric field strength increases, in the conventional example (curve t2), the dielectric voltage contact also increases by 2', but in this example (curve (1) In this case, the change in dielectric voltage contact is extremely small.

Therefore, it can be seen that this example has a superior corona discharge suppressing effect compared to the conventional example.

The present invention is not limited to the embodiments described above and shown in the drawings, and may be modified as appropriate without departing from the spirit, such as being applicable as a winding for not only electric motors but rotating electric machines in general. Of course, it can be implemented.

[Effects of the Invention] As explained below, in the winding of the rotating electrical machine of the present invention, the corona shield layer of the insulated conductor housed in the slot of the iron core is coated with a semiconductive material on the outer surface of the heat-shrinkable film. Since the corona shield layer is constructed by applying paint, it is possible to prevent the corona shield layer from adhering to the insulating layer around the conductor and causing corona discharge between these insulating layers and the corona shield layer. Therefore, it is possible to achieve an excellent effect of improving insulation properties.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is a sectional view of the main part, FIG. 2 is a partially enlarged sectional view of the corona shield layer, and FIG. 3 is a dielectric loss tangent for explaining the function. FIG. 3 is an electric field strength characteristic diagram. FIG. 4 is a sectional view of a main part of a conventional example, and FIG. 5 is an enlarged sectional view of part 7 of FIG. 4. In the drawing, 10 is a stator core, 11 is a slot, 12 is an insulated conductor, 13 is a stator winding, 14 is a conductor, 15 and 16
17 is an insulating layer, 17 is a corona shield layer, 17a is a film, and 17b is a semiconductive paint. Agent: Patent Attorney Norihiro Chika, Right: Daiko Maru Meika 2, Figure 3, Figure 4, Figure 5

Claims (1)

[Claims] 1. An insulated conductor is housed in a slot in the iron core of a rotating electrical machine, and the insulated conductor is comprised of a conductor, an insulating layer placed around the conductor, and an insulating layer placed around the insulating layer. A winding wire for a rotating electric machine, comprising a corona shield layer formed by applying a semiconductive paint to the outer surface of a heat-shrinkable film that is wound.