JPH0345620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a rotating machine winding that can effectively suppress slot discharge.

(Prior Art) Conventionally, as a means to suppress slot discharge in rotating machine windings, semiconductor paint in which carbon black or the like is dispersed is applied to the insulating surface of the slot portion of the winding, or the paint is coated with glass or nonwoven fabric. A method has been adopted in which a semiconductive tape material coated on a base material is wound.

(Problem to be Solved by the Invention) However, in the method described above, carbon black tends to precipitate, so it is necessary to apply a well-stirred paint to eliminate variations in resistance value and obtain the desired slot discharge suppression layer. The work involved is extremely complicated. In addition, in the method of applying a semiconductor paint or winding a semiconductive tape material, in the case of a vacuum pressure impregnation treatment method, which is generally adopted as a winding insulation treatment method, the impregnated resin is mixed with the paint or tape material. Since it penetrates into the inside and hardens, the semiconductivity is impaired and the desired slot discharge suppressing effect cannot be exerted. Furthermore, there is a problem in that the paint is consumed due to heat and discharge during operation of the rotating machine and the semiconductivity is impaired, making it impossible to effectively suppress slot discharge. Furthermore, in some cases, a semiconductive substance dissolved in the impregnating resin penetrates into the insulating layer, degrading the insulating performance.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotating machine winding that can maintain a stable slot discharge suppressing effect for a long period of time.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the rotating machine winding of the present invention has main insulation by winding mica tape containing a thermosetting adhesive around the conductor. A semiconductive tape material made of a mixture of aromatic polyamide fibers, aromatic polyamide fibrils, and carbon fibers and calendered is wound and heated in the core slot storage area of the layered insulated wire ring and its vicinity. It has a hardened configuration. In addition, as a semiconductive tape material, aromatic polyamide fibers, The object of the present invention can also be achieved in the same manner as described above even if a material is used in which aromatic polyamide fibrid and carbon fiber are mixed, calendered, and the surface is coated with a paint containing grafted carbon or a semiconductor paint such as silicone elastomer. It can be achieved.

Here, the above-mentioned "fibrids" generally refer to very thin tentacle-like fibrous irregularly bonded particles.

(Function) The present invention is configured as described above, and the main insulation layer is formed by winding a mica tape containing a thermosetting adhesive around a conductor. , aromatic polyamide fiber,
By winding a semiconductive tape material made by mixing aromatic polyamide fibrils and carbon fibers and calendering the material and curing it by heating, the impregnated resin produced by the vacuum pressure impregnation process became semiconductive paint or semiconductive material. It can prevent the tape from penetrating into the inside of the tape material and hardening, and it can also prevent the paint from being consumed by heat and discharge during operation of the rotating machine, thereby achieving the desired slot discharge suppressing effect without impairing semiconductivity. I can do it. Further, the semiconductive substance does not dissolve in the impregnated resin and penetrate into the insulating layer, and the insulating performance does not deteriorate.

The reason why a calendered mixture of aromatic polyamide fiber, aromatic polyamide fibril and carbon fiber was used as the semiconductive tape material is as follows.

The purpose of using carbon fiber is to make the tape electrically conductive. However, since carbon fiber alone has too good conductivity, eddy currents occur on the surface of the coil, increasing loss. In the present invention, aromatic polyamide fibers and aromatic polyamide fibrils are added in order to reduce the conductivity to an appropriate level (10 to 500 Ωcm) and suppress the increase in loss due to the generation of eddy currents. -ing

The reason why aromatic polyamide fiber is used as the insulator is that the tape is heat resistant and does not deteriorate due to heat during operation, and is flexible and can be easily wound around the outer circumference of the insulating wire. However, a tape cannot be formed using only aromatic polyamide fibers and carbon fibers because the fibers are not entangled with each other. In the present invention, by further adding aromatic polyamide fibrils to these, the tentacle-like fibrous fibrils can be entangled with carbon fibers and aromatic polyamide fibers to form a tape.

As described above, in the present invention, by using a mixture of aromatic polyamide fibers, aromatic polyamide fibres, and carbon fibers and calendering as the semiconductive tape material, it is possible to achieve an improvement that has not been seen in the past. Therefore, it is possible to obtain the desired slot discharge suppressing effect.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

The rotating machine winding of the present invention has a volume resistivity of 10 to 500 Ωcm and a thickness of 0.1 to 500 Ωcm and is made by calendering a mixture of aromatic polyamide fibers, aromatic polyamide fibrils, and carbon fibers (10 to 50% by weight). 0.25
It is constructed by winding a semiconductive tape material of mm in diameter around the outer periphery of the portion housed in the core slot of an insulated wire ring in which a main insulating layer such as mica is formed on the conductor.

Here, the main insulating layer is formed as follows. That is, as described in Japanese Patent Publication No. 18419/1984, mica is made by impregnating adhesive with laminated mica or flake mica lined (also called reinforced) with glass cloth, plastic film, nonwoven fabric, heat-resistant paper, etc. After winding the tape and in some cases wrapping glass tape or heat shrink film tape over it to protect the surface, vacuum pressure impregnation with thermosetting resin and heat curing is performed. It is formed by an impregnation method or a prepreg method (also called a resin rich method) in which mica tape is impregnated with a sufficient amount of adhesive in advance and cured under heat and pressure.

Note that bonding between the main insulating layer and the semiconductive tape material is generally performed by the following method.

After forming the main insulating layer, an adhesive is applied to the surface of the main insulating layer, a semiconductive tape is wound around the adhesive, and the adhesive is cured.

In the case of the prepreg method, the semiconductive tape is wound on the main insulating layer without applying adhesive, and then the adhesive oozes out from the semiconductive tape during heat and pressure curing, and the adhesive is cured integrally with the main insulating layer. .

After winding the semiconductive tape on the main insulating layer without applying adhesive, it is impregnated with a thermosetting resin under vacuum pressure, and then the semiconductive tape and the main insulating layer are cured together under heat and pressure. .

Now, in a semiconductive tape material made by mixing aromatic polyamide fibers, aromatic polyamide fibrils, and carbon fibers and calendering the same, the resistance value can be decreased as the amount of carbon fibers is increased. 10 ² to suppress slot discharge
Carbon fiber is mixed to give a surface resistance of 10 ⁴ Ω. Here, the calendering process is performed by pressing the entanglements between the aromatic polyamide fibers, aromatic polyamide fibrils, and carbon fibers to firmly bond them, and then the adhesive and impregnated resin in the mica tape become semiconductive. Even if the carbon fibers penetrate into the tape, the carbon fibers will not separate from each other.
This is because the resistance value does not change.

In addition, aromatic polyamide fibers, aromatic polyamide fibrils, and carbon fibers are stable against the heat, mechanical vibrations, and partial discharges that rotating machine windings receive during operation. Because it becomes fibrous and is bound by aromatic polyamide fibers and aromatic polyamide fibrils, it does not suffer from thermal deterioration, vibration deterioration, and partial discharge like conventional semiconductive paints that mix carbon powder with adhesive. It does not gradually fall off or wear out from the insulating surface due to deterioration, and can maintain a stable partial discharge suppressing effect for a long period of time.

By the way, the winding is constructed by the following three methods.

(1) The outer periphery of the part of the insulated wire ring surface to be housed in the core slot, where glass fiber reinforced mica tape containing 30 to 50% by weight of thermosetting adhesive such as epoxy resin or polyamide resin is wound around the conductor. The above semiconductive tape material is continuously wound around 30 mm outside of both ends.
After that, the straight part of the winding is placed in a hot press.
Heat and pressure cure at 150℃ for 2 hours.

(2) The above semiconductive tape material is wrapped in the same manner as in item 1 above on the surface of an insulated wire ring made by winding a glass fiber reinforced mica tape containing 10 to 20% by weight of the above thermosetting adhesive around a conductor. Turn. Thereafter, each wire ring is placed in a vacuum tank, degassed under reduced pressure, and then the insulating layer is impregnated with a thermosetting resin such as an epoxy resin under pressure, and this is taken out from the vacuum tank and heated and cured to obtain the desired winding wire.

(3) As shown in FIG. 1, a mica tape 1 having the same material composition as in item (2) above is wound around a conductor 2, and a semiconductive tape material 3 similar to the above is wound around the surface of the mica tape 1. Thereafter, this is housed in an iron core (slot) 4, and the insulated wire ring is impregnated with a thermosetting resin 5 under vacuum pressure and cured by heating. A so-called total impregnation process is performed.

In these three methods, first, in the rotating machine winding according to the present invention obtained as in (1), the semiconductive tape material contains aromatic polyamide fibers, aromatic polyamide fibrids, and carbon fibers. Because it is formed by mixing paper and calendering, the semiconductive layer formed by applying a conventional carbon black-dispersed paint will not work after being charged for 10,000 hours under an electric field of 5KV/mm in an atmosphere of 155℃. Whereas the slot discharge suppressing effect was lost due to wear and tear due to thermal deterioration and partial discharge deterioration, this kind of thermal deterioration and partial discharge deterioration is almost absent, and the partial discharge suppressing effect remains unchanged from the initial stage. I found out.

In addition, in the rotating machine winding according to the present invention obtained as in (2), the semiconductive tape material is prepared by mixing aromatic polyamide fiber, aromatic polyamide fibre, and carbon fiber and calendering the semiconductive tape material. As a result, conventional tapes coated with carbon black paint had an abnormally increased insulation resistance due to resin impregnation and hardening, and had no effect on suppressing slot discharge. It was found that the insulation resistance of the semiconductive layer did not change much due to curing, and it had a sufficient discharge suppressing effect.

Furthermore, the voltage-tanσ characteristic of the rotating machine winding according to the present invention obtained as in (3) is shown in B in FIG. It was found that by forming a paper by mixing aromatic polyamide fibrils and carbon fibers and calendering it, the slot discharge suppressing effect was significantly improved compared to the conventional one shown in Figure A. Ivy.

Note that the present invention is not limited to the above embodiments.

For example, in (3) above, as the semiconductive tape material, a semiconductive tape having the above composition is mixed with a paint containing grafted carbon, a silicone elastomer, or a mixture of 100 parts of silicone rubber and 25 to 100 parts of carbon, or an impregnated resin. The contact between the iron core and the semiconducting layer can be further improved by using a semiconductor paint coated with a semiconductor coating with little resistance change.Especially, the voltage-tanσ characteristic at the early stage of manufacturing is as shown in C in Figure 2. can be improved.

In addition, the present invention can be implemented with various modifications without changing the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, the main insulation layer is formed by winding a mica tape containing a thermosetting adhesive around a conductor, and the storage area in the core slot of the insulated coil and the vicinity thereof. Then, a semiconductive tape material made by mixing aromatic polyamide fibers, aromatic polyamide fibrils, and carbon fibers and calendering was wound and heated to harden the semiconductive paint, which melts into the impregnated resin and improves insulation performance. It is possible to provide a rotating machine winding that has a stable slot discharge suppressing effect over a long period of time without reducing the

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the rotating machine winding of the present invention, and FIG. 2 is a voltage-tanσ characteristic diagram of the same winding. DESCRIPTION OF SYMBOLS 1... Mica tape, 2... Conductor, 3... Semiconductive tape, 4... Iron core, 5... Thermosetting resin.

Claims (1)

[Scope of Claims] 1. Aromatic polyamide fibers, aromatic A rotating machine winding wire characterized in that a semiconductive tape material made of a mixture of polyamide fibrils and carbon fibers and calendered is wound and heat-cured. 2. Aromatic polyamide fibers, aromatic polyamide fibrils, and carbon are placed in the storage area in the core slot of the insulated wire ring, which is formed by winding mica tape containing a thermosetting adhesive around the conductor to form the main insulation layer, and in the vicinity thereof. A rotary machine winding characterized in that a semiconductive tape material made by mixing fibers, calendering the paper, and further applying a graft carbon-containing paint or a semiconductor paint such as a silicone elastomer on the surface thereof is wound and cured by heating.