JPS59213247A - Winding for electric machine - Google Patents

Abstract

PURPOSE:To enable to hold the corona resistance of a slit liner over a long period by forming the liner by mixing carbon fiber and polyamide fibrid with polyamide fiber and thermally compressing the mixture. CONSTITUTION:A slot liner 5a is formed by mixing carbon fiber as a conductivity imparting material with a small amount of polyamide fibrid as a holding material between fibers by using polyamide fiber as a basic material. In other words, carbon fiber is uniformly mixed with the polyamide fiber to form a non- woven fabric, which is thermally compressed to raise the density as a slot liner. In this manner, the initial surface resistivity can be maintained even if worn, thereby holding the corona resistance over a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to an electric machine winding, and particularly to an electric machine winding installed in a slot of an iron core via a slot liner.

[Background of the invention]

Generally, induction motors and AC generators operated at high voltage (1'(i)
As shown in Fig. 1, the ELL machine winding of the machine consists of a semi-conducting f1 layer 3 formed on a ground insulating layer 2 formed on the winding and wire conductor, and However, when the heavy machinery winding 4 is installed in one slot, the semiconductive layer 3 and the ground insulating layer 2 are removed from the slot at the time of installation. If it is damaged by the corners or side walls, etc. (2 inches long, the corona prevention function of the electric machine winding 4 and the insulation layer 1 will be degraded and destroyed).

For this reason, as shown in FIG. 2, the electric wire 4 is assembled into the slot 6S of the iron core 6 via the slot liner 5, but the slot liner 5 has semiconducting properties on its front and back surfaces. Paint is applied, and the semiconductive paint on the front and back sides are electrically connected at the overlapped portion P. For this reason, the semiconductive layer 3 of the winding 4 is electrically connected to the iron core 6 via the semiconductor on the front and back sides of the slot liner 5 and the semiconductive silk. Inserted electric machine winding 4 (/
j: Fixed with Wet/7, then impregnated with adhesive and cured.

By the way, the above-mentioned slot liner 5 is made of Teto's 4B material such as non-woven fabric, crow cloth, film strip, etc., and a semi-conductive paint containing conductive substances such as carbon powder is applied to the front and back sides of the material. A coated material is used. In other words, the base material is an insulating material such as a heat-compressed sheet of woven fabric or non-woven fabric such as glass cloth, or porous material, and a semiconductive paint is applied to the front and back of this material. As the semi-conductive paint is coated on the surface of the iron core 6, the semi-conductive paint on the contact surface with the iron core 6 will wear out if the heavy equipment is exposed to the cooling/heating cycle caused by repeated starting and stopping or electromagnetic force during operation. When the semiconductive paint wears away, the surface resistivity of the slot liner 5 increases, the surface potential of this part increases, corona discharge occurs, and the slot liner 5 no longer performs its function. One thing is missing.

[Purpose of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide an electric machine winding having a slot liner that can maintain long-term corona resistance.

[Summary of the invention]

That is, the present invention is characterized in that the slot liner is made of a mixture of polyamide fibers, nicarbon fibers, and polyamide neubrit, and is thermally compressed.

In order to prevent the characteristics from changing even if they wear out due to contact with the iron core, it is better to use a material whose characteristics are uniform throughout the interior. For this purpose, a conductive fiber that imparts conductivity is used, and this is mixed with the fibers of the insulating material of the base material to form the slot liner. In this way, the slot liner will have a uniform grain structure, so the resistance value will be uniform not only across the surface but also inside the slot liner as in the past, so that even if the surface is worn out, it will still come into contact with the iron core. The resistance value is maintained at the same value as the initial surface resistivity, and the surface corona property of the electric machine winding can be maintained for a long period of time. In order to obtain the surface resistivity of the first power period, it is sufficient to change the composition ratio of the fibers of the base material and the conductive fibers, and to obtain a uniform slot liner, it is necessary to use polyamide as the insulation material. Using fiber,
It was confirmed that this material should be mixed with carbon fibers as conductive fibers and polyamino neubrit for holding the fibers, and then thermally compressed. Therefore, in the present invention, the slot liner is formed by mixing polyamide fiber with carbon fiber and polyamide neubrit, and then thermally compressing the mixture.

By doing so, it is possible to obtain an electric machine winding having a slot liner that can maintain corona resistance for a long period of time.

Embodiment of C-ray ψj] The present invention will be described below based on the illustrated embodiment of cyano. FIG. 3 shows an embodiment of the invention. Note that I, ia, and J are omitted because the same parts as in the past are given the same reference numerals. In this embodiment, slot liner 5.! was formed by mixing polyamide fiber with carbon fiber and polyamide neubrid, and then thermally compressing the mixture. By doing this, the internal grain becomes sharp and the initial surface resistivity is maintained even if it wears out, thereby maintaining corona resistance over a long period of time. The electric machine winding 4a with the slot liner 5a made possible is now! I can do a lot of things.

Regarding the above-mentioned examples, the properties of 1st and 2nd grooves were investigated by applying semi-conductive paint, and the characteristics of the two grooves were investigated. is as described below.

That is, the liner used in this example was made of polyamide fiber as the base material as described above, and carbon fiber and these fibers IH were used as the conductive material.
It was formed by mixing a small amount of polyamino neubrit as a holding material for I. That is, carbon fibers were uniformly mixed with polyamide fibers, paper was made into a nonwoven fabric, and this nonwoven fabric was thermally compressed to increase its density to form a slot liner. During this thermal compression process, polyamiton hybrid
It is used to hold the amide fibers and carbon fibers together. The electric machine winding having a semi-conductive layer on its surface is connected to the slot of the iron core through the wire wire made in this way and whose surface and volume resistivity are 1: shown in the table. After fixing it with a wedge, it was impregnated with evoquino resin and turned into an image to obtain Sample A of the Example.

On the other hand, the slider liner used in Comparative Example J was formed by using 0.131 nm thick polyamide paper as the base material and applying semiconductive paint to both sides. A resin mixed with carbon powder is used, and the mixing amount is polyimide resin 100m:ffi'%
The coating amount is 35% by weight relative to polyamide paper, and the coating amount is 40 times per 100% polyamide paper. In this way,
A comparative example of an electrical winding wire that was assembled into the slot in the same manner as in the above case using a slot liner whose surface and volume resistivity are shown in the table below and treated with epoxy 7 resin. It was set as B.

Sample C of Comparative Example 2 uses a porous insulating polyester nonwoven fabric for the slot liner, and all comparisons are made except that the slot liner whose surface and volume resistivity are as shown in the table below. This is similar to Example 1.

We investigated corona discharge, that is, partial discharge inception voltage characteristics and dielectric loss tangent characteristics when repeatedly subjected to cooling and heating cycles for Example A, Comparative Example B, and Comparative Example C. iiM degree is heated and cooled so that the lowest temperature is room temperature and the highest temperature is 180C, and this temperature is 0.
I turned around 000 times. Changes in the partial discharge inception voltage characteristics were tracked with the initial partial discharge inception ILL pressure set as a factor of 100, and changes in the dielectric loss tangent characteristics were tracked using the initial dielectric loss tangent when 2 kV was applied as a factor of 100.

The results of examining the partial discharge inception voltage characteristics are as follows: The vertical axis represents the partial discharge inception voltage, and the horizontal axis represents the number of repetitions of heating and cooling cycles.
As shown in FIG. 4, which shows the change characteristics of partial discharge inception voltage depending on the number of repetitions of heating and cooling cycles, the partial discharge inception voltage of Example A did not decrease even after 1000 heating and cooling cycles, and Comparative Examples I3 and Superior to Comparative Example C. This is because the surface resistivity of the slot liners used in Comparative Examples B and C changes due to wear, whereas the surface resistivity of the slot liner used in Example A does not change due to wear. .

The examination results of the dielectric contact characteristics are shown as 4:b with the dielectric loss tangent on the vertical axis.
As shown in Figure 5, where the number of repetitions of heating and cooling cycles is taken as 1fqi, the change characteristics of the dielectric loss tangent depending on the number of repetitions of heating and cooling cycles are shown. Comparative example B
and is superior to Comparative Example C. This 7L is due to the same reason as mentioned above.

〔Effect of the invention〕

As described above, the present invention prevents the surface resistivity from changing even if the slot liner is worn out, so that the surface resistivity does not change and the resistance to corrosion can be maintained over a long period of time. Therefore, it is possible to obtain an electric machine winding having a slot liner that can maintain corona resistance for a long period of time.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a conventional electric machine winding (ft11 side view), Fig. 2 is a longitudinal cross-sectional side view showing a conventional 'il FIG. 4 is a longitudinal sectional side view showing a state in which one is incorporated into a misaligned machine according to an embodiment, and FIG. Fig. 5 is a change characteristic diagram of the dielectric loss tangent depending on the number of repetitions of the cooling/heating cycle between the electric machine winding of this embodiment and the i-steep winding of the conventional example. !Conductor, 2...Ground insulating layer, 3...Semi-conductive layer, 4;] Electrical winding, 5a...Suronotoshii-1, 6 iron core, 6S...Slot. Agent: Patent attorney Susumu Nagasaki Chikara (and 1 other person) 2nd eye 4th day camellia S Figure 9 Shishi-drum (times) representing the seaside Ikuru system

Claims (1)

[Claims] 1. In an electric winding wire that is installed through a slot liner within the iron core and has a winding conductor, a ground insulation layer, and a semiconductive layer, the slot liner is made of polyamide fibers and carbon fibers. An electric machine winding wire characterized in that it is a mixture of paper and polyamide neubrinoid and is thermally compressed.