JPH0670499A - Stator coil for high voltage rotary electric machine - Google Patents

Abstract

PURPOSE:To provide a method in which impregnating properties of a slot insertion part of a stator coil for a high voltage rotary electric machine are improved and an impregnating time can be shorted. CONSTITUTION:A dry mica tape 3 of a film base material is wound on a conductor 2 to form an insulator to ground. A semiconductive tape 5 having many fine holes is wound on a slot insertion part A on the insulator to the ground, inserted into the slot, wired, then resin-molded, vacuum-evacuated, and pressure impregnated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing corona in a slot of a stator coil of a high pressure rotating machine.

[0002]

2. Description of the Related Art A ground insulation method for a stator coil of a generator and an induction motor up to a medium-sized machine of 3 kV or more is performed by winding dry mica tape around a conductor, inserting a slot, and connecting a resin. Vacuum and pressure impregnation, and heat curing is performed.

The backing material for dry mica tape includes glass cloth, film, non-woven fabric, etc., but mechanical winding using a taping machine has an appropriate elongation, a high breakdown voltage, and is relatively inexpensive. Dry mica tape, which is the backing material for the film, is often used.

The backing material of the dry mica tape and the mica tape are attached with a small amount of adhesive.

FIG. 5 shows a conventional fully impregnated hexagonal stator coil 1. FIG. 6 shows a sectional view taken along the line AA in FIG. In FIG. 6, a conductor 2 is coated with a film-based dry mica tape (hereinafter referred to as film mica tape) 3 so as to have a thickness corresponding to a rated voltage.
Suppress ground insulation. A semiconductive tape 4 for suppressing partial discharge generated between the stator coil and the iron core slot is wound around the slot insertion portion A of the film mica tape layer wound around a predetermined thickness.

By the way, the resin cannot penetrate the film mica tape 3 from the direction perpendicular to the film surface, but penetrates only from the overlapping portion of the film mica tape 3 as shown by the arrow in FIG. Therefore, when the tape is wound with tension in order to fit it within a certain size range, the gap between the tapes becomes smaller than that when the tape is loosely wound, and it takes time for the resin to penetrate.

The semi-conductive tape 4 is made of glass cloth, non-woven fabric, a liquid obtained by mixing graphite carbon particles with varnish.
It is applied to a substrate such as a film.Generally, the resin cannot penetrate from the direction perpendicular to the tape surface and penetrates from the overlapping part of the tape like film mica, so the slot insertion part is not The time required for impregnation is longer than that for the part.

[0008]

As described above, the conventional method requires a long time for the impregnation work. An object of the present invention is to provide a stator coil of a high-pressure rotating machine, which can improve impregnation property of a slot insertion portion and can reduce impregnation time.

[0009]

[Means for Solving the Problems] The above-mentioned object is to wind a dry mica tape of a film base around a conductor, insert a stator coil of a high-voltage rotating machine having a ground insulating layer into a slot, and heat cure the same. In a stator coil of a high-voltage rotating machine impregnated with a conductive resin to form an insulating layer, a semiconductive tape having a large number of minute holes previously formed is wound around a slot insertion portion of the coil. Achieved by the stator coil.

[0010]

When a semi-conductive tape having a large number of holes is used, as shown in FIG. 1, there are many paths through which the resin penetrates, and the distance to the overlapping portion of the lower film mica tape layer is short. As a result, the impregnation property, which has been hindered by the conventional tape, is improved, and the risk of insufficient impregnation of the slot insertion portion can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. 1 is a sectional view of an embodiment of the present invention in which the straight line portion of FIG. 5 is taken out, and FIG. 2 shows a semiconductive tape used in the embodiment of the present invention.

In FIG. 1, a film mica tape (base material: polyimide film) 3 is placed on the conductor 2 at a rated voltage.
A layer equivalent to the 6.6kV class is wound six times with half-lap winding to form ground insulation. Next, as shown in FIG. 2, only the slot insertion portion A of FIG.
The semiconductive tape 5 of the present invention having a width of m and a width of 12.5 mm is wound so that the ends of the tape are overlapped by about 1 mm. The diameter of the hole at this time is 1
mm or less is desirable, and the number is preferably 4 to 5 pieces / cm ² . In the present embodiment shown in FIG. 2, fine holes are formed at intervals of 6 mm in the length direction and the width direction, respectively, and a distance of 3 mm from the center of the square formed by the hole positions, that is, from the column and the row, respectively. A small hole was also made at the position. After winding this semi-conductive tape 5 and inserting it into the model iron core,
Pre-dry in a drying oven at ℃. Remove from drying oven and transfer to vacuum impregnation tank. At this time, in order to monitor the permeation state of the resin by the change in capacitance, lead wires are preliminarily output from the conductor 2 of the coil and the semi-conductive tape 5 (4 in the case of the conventional coil), and the terminal block of the vacuum impregnation tank is used. External C via
Connect to the meter. Next, after degassing at 10 mmHg or less, resin injection, vacuum evacuation and pressurization of 5 kg / cm ² are performed.
Each working time is shown in FIG.

FIG. 3 is a comparison of changes in capacitance due to resin penetration of the present invention and the conventional method. From FIG. 3, it can be seen that in the case of the present invention, the capacitance saturates in a shorter time than the conventional method.

A sine wave voltage of 50 Hz and 12 kV was applied at 200 ° C. to the coil of the present invention and the conventional coil manufactured as described above, and the time until dielectric breakdown was measured. FIG. 4 shows the comparison data. Conventional type coil is about 2400-3200
While the coil of the present invention was destroyed in time, one coil was destroyed and two coils were not destroyed in 4800 hours.

Further, the minute holes formed in the semiconductive tape were completely filled with the impregnated resin, and it was observed that the coil broke in 4800 hours, but it was recognized that this part was particularly deteriorated. There wasn't.

[0016]

According to the present invention, a large number of minute holes are formed in the semiconductive tape to improve the impregnation property, so that the impregnation time can be shortened and the insulation reliability can be improved. did it. It should be noted that the width of the semi-conductive tape may be made wider than that of the embodiment according to the conductor size.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention in which a straight portion of a hexagonal coil is taken out.

FIG. 2 is a plan view of a semiconductive tape used in an example of the present invention.

FIG. 3 is a graph comparing changes in electrostatic capacitance between a coil of the present invention and a conventional coil due to resin penetration.

FIG. 4 is a graph showing a result of a comparison test of a coil according to the present invention, a coil of a conventional system, and a voltage application life.

FIG. 5 is a plan view of a conventional fully impregnated hexagonal stator coil.

FIG. 6 is a sectional view taken along the line AA in FIG.

[Explanation of symbols]

1 Conventional total impregnation type hexagonal stator coil 2 Conductor 3 Film-based dry mica tape (film mica tape) 4 Semi-conductive tape 5 Semi-conductive tape A of the present invention A Slot insertion part of coil

Continued Front Page (72) Inventor Shin Tsuchiya 338, Ogino, Kamisakuyanagi, Yamato City, Kanagawa Prefecture, Toyo Denki Seizo Co., Ltd.

Claims (1)

[Claims] 1. A dry mica tape, which is a film base material, is wound around a conductor, a stator coil of a high-voltage rotating machine having a ground insulating layer is inserted into the slot, and a thermosetting resin is impregnated to form an insulating layer. A stator coil for a high-voltage rotating machine, comprising: a stator coil for a high-voltage rotating machine, wherein a semi-conductive tape having a large number of minute holes formed in advance is wound around a slot insertion portion of the coil.