JPS5815444A - Insulating coil for high-voltage - Google Patents

Abstract

PURPOSE:To facilitate manufacturing work and to improve characteristics by a method wherein a semiconductive material mixed aromatic polyamide fiber, aromatic polyamide microconnector and carbon fiber is wound on the extremely outside layer of an insulating layer located in an iron core groove. CONSTITUTION:A semiconductive sheet or tape made by mixing aromatic polyamide fiber, aromatic polyamide microconnector, and carbon fiber is wound on the extremely outside layer of the insulating layer 4 of a coil conductor 3 located in an iron core groove to form a partial discharge preventive layer 6. This facilitates manufacturing work and improves partial discharge proof characteristics and electrical characteristics as well.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulated wire ring having a portion inserted into a core groove, such as a winding of a rotating electric machine (part 1, 9, especially (secondary iron core part)). Required high-voltage insulated wire rings (related to 1).

In high-voltage insulated wire rings that have a portion that is inserted into the core groove, the surface of the insulating layer of the wire generates an electric field in the portion that is inserted into the core groove, which generally causes a partial discharge called corona. , which can significantly shorten the life of the insulating layer. Therefore, in order to extend the insulation life, it is necessary to prevent partial discharge in the iron core, and as a countermeasure, the surface of the wire insulating layer is made semiconductive. Conventionally, this method involves wrapping an insulating tape or sheet around the wire conductor, impregnating it with resin, and curing it to form an insulating layer. Either apply a conductive paint to provide a partial discharge prevention layer, or wrap an insulating tape or sheet around the wire conductor and coat the outermost layer of the part inserted into the core groove with a semiconductive resin in advance. After wrapping the treated semiconductive material around the fibers, it was impregnated with resin and cured.

The former method involves applying and curing semiconductive paint, which is inevitable (= the manufacturing process is also longer), so in recent years, the latter method of wrapping semiconductive materials has been used. The semiconductive material used is a tape made of glass fiber with excellent corona resistance as a base material and treated with a semiconductive resin in which carbon powder is mixed into the resin.

However, when glass fibers are treated with semiconductive resin, the tape becomes hard9, and the glass fibers themselves have little elongation, making it difficult to wrap the tape, requiring a long time to complete the tape, and making the tape difficult to finish. Lack of adhesion between layers. Therefore, as shown in FIG. As shown in Figure 2, voids (
5) may start to occur. In FIGS. 1 and 2, the partial number prevention layer (6) and the voids (5) are shown enlarged. If such a gap (5) is formed, when a high voltage is applied (-1), partial discharge is likely to occur in this gap (5), and even though a partial discharge prevention layer (6) is provided,
In some cases, the effect was not sufficient.

The purpose of the present invention is to have good work efficiency in manufacturing, and to have excellent high efficiency in use (2).
Our objective is to provide edge wire wheels for FF Futagawa.

Hereinafter, one embodiment of the present invention will be described with reference to FIG.

A wire conductor (1) is subjected to wire insulation (2), and a plurality of wire insulation (2) are connected to each other to form a wire ring conductor (3). An insulating layer (4) is formed by winding mica tape or the like around the insulating layer body (3) for ground insulation, and is inserted into a core groove (not shown).
(Secondly, a partial centering prevention layer (6) is provided using one roll of the semi-conductive tape as described below, and the entire wire is impregnated with a thermosetting resin and cured by heating. The tape is a mixture of aromatic polyamide fibers, aromatic polyamide fine binders, and carbon fibers, and the amount of carbon fibers is varied depending on the required resistance value.

Next, the initial action will be explained.

The semiconductive tape used to form the partial discharge prevention layer (6) of this example has some differences in elongation and heat shrinkability depending on the blending ratio of its components, but it is different from the conventional glass base material. Compared to a tape treated with a semi-uniform resin mixed with carbon powder, the elongation and heat shrinkage properties are significantly lower as shown in Figures 4 and 5. , In Fig. 5, (a) is the conventional tape, and (b) is the tape of this embodiment, but if you look at Fig. 4, the elongation of the conventional tape (a) is only about 0.2% (2). The tape (b) of this example has an elongation of about 1.8 to 2.8.

Therefore, the tape (b) of this example is very unsoft,
Easy to wind and high work efficiency. There are still no gaps or wrinkles between the pair of insulating layers (4) or between the turns, resulting in an insulated wire ring with excellent partial discharge prevention performance. Furthermore, as shown in FIG. 5, the thermal shrinkage rate of the conventional tape (a) is almost zero, whereas the tape (b) of this embodiment has a very high thermal contraction rate of about 8 to 22%, so that the insulation Kt ( -1) together with the partial discharge prevention layer (6) (1) also when impregnated with a thermosetting resin and cured by heating,
The partial discharge prevention layer (6) shrinks following the curing heat shrinkage of the internal insulating layer (4), without forming voids or wrinkles between the counter insulating layer (4) or between the turns. ), resulting in an insulated wire ring with excellent partial discharge prevention performance. Figure 6 shows the partial discharge prevention performance compared with the conventional tape. While it is distributed in a range,
The tape (b)' used in this example was about 1.
The distribution was in the range of 30 to 150%, and it can be seen that this example is particularly excellent. Ushida tanδ-
The voltage characteristic test results are as shown in Figure 7.9, curve a
It can be seen that compared to the tape using the conventional tape (a) shown in curve b (-), the tape using the tape (b) of this example shown in curve b (-) is much better in the high electric field region by (2). The material of this example also had good heat resistance.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings (the two added examples, for example, the partial discharge prevention layer (6)
Of course, it is possible to modify the tape in various ways without changing its gist, such as without resin treatment or heat treatment, and the semiconductive tape used can be changed into a sheet. .

As explained above, according to the present invention, a semi-conductive tape or thread made of a mixture of aromatic polyamide fibers, aromatic polyamide fine binders, and carbon fibers is applied to the insulating layer located in the core groove. Since the partial discharge prevention layer is wound around the outermost layer, manufacturing work becomes easier, and there is no bending of the insulation layer in the partial discharge prevention layer or gaps or wrinkles between the turns, improving partial discharge prevention performance. In addition to the above, other electrical properties are also improved, which has the effect of making reliable high-voltage insulated wire rings cheaper.

[Brief explanation of the drawing]

Fig. 1 is an enlarged longitudinal cross-sectional view of the main part of a conventional high-voltage insulated wire ring, Fig. 2 is an enlarged cross-sectional view of the main part of Fig. 1, and Fig. 3 is an enlarged cross-sectional view of the main part of a conventional high-voltage insulated wire ring. A cross-sectional m1 diagram showing one embodiment, FIGS. 4 and 5 are diagrams, and FIGS. FIG. 7 shows the partial discharge inception voltage and ta of high-voltage insulated wire rings of the conventional and one embodiment of the present invention.
FIG. 3 is a diagram showing a comparison of nδ-voltage characteristics. 3... Wire conductor 4... Insulating layer 6... Partial discharge prevention layer Female back cover - Me ] Desired machine hood M1 = 4 ? b [leopard guv4-

Claims (2)

[Claims] (1) In a high-voltage insulated wire ring having a portion inserted into the core groove, the outermost layer of the insulating layer located within the core groove of the insulated wire ring (2. Aromatic polyamide fibers and aromatic polyamide fine binders) A high-voltage insulated wire ring characterized by having a partial discharge prevention layer wound with a semiconductive tape or sheet made of a mixture of carbon fiber and carbon fiber. (2) The high voltage insulated wire ring according to claim 1, wherein the partial discharge prevention layer is impregnated and cured with a thermosetting resin together with the insulating layer.