JPH0773424B2 - Superconducting generator and stator parts - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of a superconducting generator.

[0002]

2. Description of the Prior Art In a stator of a generator before the development of a superconducting generator, a cylindrical magnetic shield member having an annular cross section and a tooth portion provided on the inner wall thereof have the same magnetic property. It was composed of a laminated structure of punched steel plates. However, as described on page 11 of the Technical Report of the Institute of Electrical Engineers of Japan (Part II) No. 192 (July 1985), in superconducting generators, the purpose is to reduce eddy current loss due to the effect of a strong magnetic flux density. As a result, the teeth are replaced with a non-metallic material, that is, a non-conductive material while sacrificing magnetic properties, and the teeth are arranged only for supporting the stator coil arranged between the teeth. Became. A fiber reinforced plastic (hereinafter abbreviated as FRP) using glass fiber is adopted as a constituent material of the tooth portion from the viewpoint of moldability and strength, and the tooth portion formed in a plate shape is laminated in the axial direction of the generator. And is fixed to the inner wall of the magnetic shield member. By the way, a corona shield layer is formed on the outermost layer of the stator coil of a high-voltage generator in order to prevent corona generation. The grounding of the corona shield layer was performed through the presence of magnetic steel plate teeth in the case of the stator coil of the generator before the development of the superconducting power generator.

[0003]

However, in the superconducting generator, the teeth are replaced by non-conductors, so that the space between the magnetic shield member disposed outside or the stator frame disposed outside thereof is further increased. Since it is necessary to ground the conductor to measure continuity with any one of them, extra labor is required. Moreover, it is not easy to reliably capture the relatively thin and fragile corona shield layer of the stator coil that vibrates during operation to ensure electrical continuity with the ground.

It is an object of the present invention to provide a superconducting generator stator component that reliably grounds the corona shield layer of the stator coil while suppressing an increase in tooth eddy current loss due to the influence of a strong magnetic flux density. It is in.

[0005]

DISCLOSURE OF THE INVENTION A plate tooth component including a semi-conductive and highly rigid non-metallic material is arranged on at least a part of a generator tooth axial arrangement of a non-conductive material. To do. If necessary, a semi-conductive elastic cushion is inserted between the teeth and the corona shield layer to ensure contact between the corona shield layer of the stator coil and the semi-conductive plate-like tooth part. , And / or a semi-conductive adhesive material is used to fix the corona shield layer and the teeth.

[0006]

[Function] By arranging the semi-conductive plate-like tooth part in a part of the non-conductive tooth part in the axial direction of the generator, the increase of the tooth eddy current loss due to the influence of the magnetic flux density is suppressed and the stator coil maximum is reduced. The outer corona shield layer can be grounded at the same time. This eliminates the need for grounding the conductor of the separately placed corona shield layer, which is economical.

If this semi-conductive tooth component has a high elastic modulus, it is more suitable as a contact support member for the stator coil. FR when FRP is used for plate tooth parts
A material having a high elastic modulus is selected as P, and at the time of molding the plate-shaped tooth part, the fiber direction is almost aligned in the radial direction in the cross section perpendicular to the generator shaft when assembled to the generator stator and in the perpendicular direction. , Increase the elastic modulus in the same direction.

When all the fibers in one plate-shaped tooth part are made of semi-conductive fibers, if the tooth eddy current increases too much, the semi-conductivity in the axial direction of the generator in one plate-shaped tooth part is increased. Take measures by reducing the fiber distribution. Conversely, if it is possible to avoid the tooth eddy current loss problem, make all the fibers of all tooth parts semi-conductive so that even if the stator coil vibration occurs, somewhere in the stator coil Make sure that the corona countermeasure works by contacting the conductive teeth.

When it is impossible to adopt the semiconductive plate-like tooth part parts on the whole surface, especially when the whole semiconductive tooth part is formed, the semiconductive elastic cushion is used, or By adopting a fixing method between the corona shield layer and the semiconductive tooth portion by using a semiconductive adhesive material, the electrical connection between the corona shield layer and the ground is secured and reliability is improved.

[0010]

EXAMPLES The present invention will be described below with reference to examples.

FIG. 1 is a sectional view of the upper half of the superconducting generator stator cut along the generator axis. FIG. 2 shows A of FIG.
It is sectional drawing cut | disconnected along the A sectional line. The dovetail 2 is used on the inner wall of the cylindrical magnetic shield member 1 in which magnetic metal materials having a ring-shaped cross section disposed on the outer side are laminated, and the tooth portion 3 formed into a plate shape by FRP using the dowel tail 2 is fixed. The generator axial direction arrangement in the tooth portion 3 in the present embodiment is a semi-conductive FRP tooth using carbon fiber as the base material at the center and both ends of the non-conductive FRP tooth component 31 using glass fiber as the base material. The parts 32 are arranged. A slot 5 for housing the stator coil 4 is provided between the teeth, and the stator coil 4 having a semiconductive corona shield layer in the outermost layer housed therein is attached to the teeth 3 by the wedge 6. It is firmly fixed. There are various methods for arranging the fibers 7 when creating the FRP, and it is common to stack the fibers parallel to a plane perpendicular to the axis with respect to the axial direction of the generator, but the fibers in the plane perpendicular to the axis Any direction can be selected. Further, the fibers 7 can also be in a loose state or a woven state. However, among these, as shown in the enlarged view of FIG. 2, the fibers 71 arranged substantially perpendicular to the surface B facing the stator coil 4 and the surface C facing the inner wall surface of the magnetic shield member 1 are almost the same. It is optimal to use a woven fabric in which the fibers 72 arranged vertically are arranged in the direction in which the fibers 72 are arranged, in terms of elastic modulus and rigidity, and handling. In order to electrically connect the corona shield layer and the magnetic shield member 1, the fiber 71 in the semiconductive FRP is used.
It is important that the intersection point D of the fiber 72 and the fiber 72 is electrically and reliably connected. A plain-woven carbon fiber woven fabric was used as the fiber 7 of the semi-conductive FRP in this example to satisfy these requirements. In addition, we decided to use an epoxy resin for the FRP matrix.

In the measurement of the present embodiment, the volume resistivity between the surfaces B and C of one plate-like tooth component shows a value of 40 μΩm, and the corona shield layer of the stator coil has this semiconductive circuit. Through the magnetic shield member. The carbon FRP 32 has a modulus of elasticity 6000 kg / mm ² which is about three times as large as that of the glass FRP 31, and the corona shield layer is strongly pressed against the carbon FRP 32 even when the stator coil 4 vibrates due to electromagnetic force. The electrical connection between the corona shield layer and the carbon FRP was kept good. On the other hand, the eddy current loss in the semiconductive tooth part component 32 due to the rotating magnetic field having a strong magnetic flux density was 1/100 or less of that in the case of using the nonmagnetic metal material tooth part.

Next, by changing the axial arrangement of the semi-conductive FRP tooth parts 32 in the generator axial direction, only the both ends, to one or several suitable positions, the same measurement was carried out. It was found to show a grounding effect. Further, when the magnetic flux density is small and it is not necessary to pay attention to the eddy current loss, the entire tooth portion 3 can be composed of only the semi-conductive FRP tooth portion component 32. In this case as well, the corona shield layer of the stator coil 4 can be used. The electrical connection between the magnetic shield member 1 and the magnetic shield member 1 was kept good.

As a second embodiment, the carbon FRP fiber material is changed to satin weave fabric or roving fabric, and FR
When the matrix of P was changed to epoxy resin, polyimide resin, polyester resin, etc., almost the same effect could be obtained.

As a third embodiment, FIG. 3 shows a semiconductive FR.
The thing which the structure of P tooth | gear part component 32 differs is shown. That is,
The fiber composition distribution in the axial direction of the generator in one tooth part is divided into a semi-conductive fiber layer, for example, a carbon fiber layer 73 and a non-conductive fiber layer, for example, a glass fiber layer 74. By adopting such a fiber arrangement, the resistivity of the plate-shaped tooth part component is slightly increased, but the tooth part eddy current loss can be significantly reduced. Since the eddy current loss is proportional to the cube of the thickness of the semiconductive portion that is integrated,
The non-conductive fiber layer 74 allows the semi-conductive fiber layer 73 to
In the case of dividing into two, the eddy current loss of the semiconductive FRP tooth part component 32 is not divided and the semiconductive fiber layer 73 of the same thickness is used.
It becomes 1/8 or less of the case of using. However, if the eddy current loss is allowed, it is not always necessary to divide it, and if the contact with the corona shield layer is maintained, the number of divisions may be increased.

In any of the above-described embodiments, it is necessary to improve the reliability of the electrical connection between the corona shield layer of the stator coil 4 and the semiconductive tooth component 32. come. In order to ensure the electrical connection even when a sudden current occurs due to a short-circuit accident of the generator, for example, a corona shield layer and a semi-conductive tooth using a semi-conductive adhesive material such as an epoxy resin added with carbon powder. The part 32 is bonded. For a stator coil having a high temperature and a large deterioration over time, a semi-conductive elastic cushion such as a semi-conductive corrugated sheet having a spring coefficient of about 1 to 50 kg / mm is used as shown by reference numeral 8 in FIG. When it is inserted into the portion 3 of the slot 3 in contact with the surface B of the slot 5, the reliability of the electrical connection between the corona shield layer and the tooth component 32 is greatly improved. Further, the reliability is further improved by bonding with a semiconductive adhesive material. Structurally, this semi-conductive elastic cushion 8 is made up of the semi-conductive tooth part 3
It is important to insert not only the span of 2 but also the entire length of the tooth portion 3 in the axial direction of the generator.

[0017]

EFFECTS OF THE INVENTION By inserting semiconductive tooth parts whose number is determined according to the magnitude of the magnetic flux density of a superconducting generator between non-conductive tooth parts or between tooth ends, the tooth part vortex is formed. It has become possible to simultaneously suppress the increase in current loss and ground the corona shield layer of the stator coil. Furthermore, by fixing with semi-conductive adhesive material and inserting the semi-conductive elastic cushion in the slot, it was possible to improve the reliability of the grounding of the corona shield layer even after aged deterioration even when a huge vibration occurred.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an upper half of a superconducting generator stator cut along a generator axis.

2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a structural explanatory view of a semi-conductive tooth portion in which one portion of semi-conductive fiber is used in one block and non-conductive fiber is used in the other thickness.

FIG. 4 is the same sectional view as FIG. 2 when a semiconductive elastic cushion is inserted into a slot.

[Explanation of symbols]

 1 Magnetic Shielding Member 3 Teeth 4 Stator Coil 7 FRP Fiber 8 Semi-Conductive Elastic Cushion 31 Non-Conductive FRP Tooth Part Parts 32 Semi-Conductive FRP Tooth Part Parts 71 Fibers Perpendicular to Slot Surface 72 Magnetic Shielding Member Fibers perpendicular to the inner wall

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiki Sato 4026 Kujimachi, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Takashi Haruta 3-1-1, Saiwaicho, Hitachi City, Ibaraki Company Hitachi, Ltd. Hitachi factory (72) Inventor Yasuomi Yagi 3-1-1, Saiwaicho, Hitachi, Ibaraki Stock company Hitachi Ltd. Hitachi factory

Claims (18)

[Claims] 1. A plurality of cylindrical magnetic shield members and a plurality of plate-shaped tooth parts formed in a plate shape by a non-conductive material are laminated.
A tooth portion which is fixed to the inner wall of the magnetic shield member becomes Te, the superconducting generator having a stator with a stator coil having a corona shield layer on the outermost layer is arranged between the teeth portion, said teeth A superconducting generator, wherein a plate-shaped tooth component including a semi-conductive material is arranged on at least a part of a generator axial arrangement. 2. The superconducting generator according to claim 1, wherein the plate-shaped tooth component including the semiconductive material has a higher elastic modulus than other plate-shaped tooth components. 3. The superconducting generator according to claim 1, wherein the plate-shaped tooth part component containing the semiconductive material is made of carbon fiber reinforced plastic. 4. The superconducting power generator according to claim 3, wherein the carbon fiber reinforced plastic is molded using a carbon fiber woven fabric laminated in the axial direction of the power generator. 5. The superconducting generator according to claim 4, wherein the fiber directions of the respective carbon fiber fabrics are substantially aligned with the radial direction of the stator of the superconducting generator and the direction perpendicular thereto. 6. The plate-shaped tooth component including the semiconductive material according to claim 1, wherein the plate-shaped tooth component is made of carbon fiber reinforced plastic, and the other plate-shaped tooth component is made of glass fiber reinforced plastic. And a superconducting generator. 7. The plate-shaped tooth part component containing the semiconductive material according to claim 1, wherein a plurality of fiber woven fabrics are laminated, and at least one layer of the fiber woven fabric is a semiconductive fiber woven fabric, and the others are non-woven fabrics. A superconducting generator, which is a conductive fiber woven fabric. 8. The superconducting power generator according to claim 7, wherein the semi-conductive fiber woven fabric is a carbon fiber woven fabric, and the non-conductive fiber woven fabric is a glass fiber woven fabric. 9. The superconducting generator according to claim 1, wherein all of the tooth portions are constituted by plate-shaped tooth component parts including a semiconductive material. 10. The superconducting power generator according to claim 1, wherein the stator coil having the corona shield layer and the tooth portion are fixed to each other by using a semiconductive adhesive material. 11. The superconducting generator according to claim 1, wherein a cushion made of a semiconductive elastic body is inserted between the stator coil having the corona shield layer and the tooth portion. 12. The superconducting generator according to claim 11, wherein the stator coil, the semiconductive elastic body cushion, and the tooth portion are fixed to each other by using a semiconductive adhesive material. . 13. A plurality of cylindrical magnetic shield members and a plurality of plate-shaped tooth parts formed in a plate shape by a non-conductive material are laminated.
A tooth portion which is fixed to the inner wall of the magnetic shield member made by, the plate-like teeth of a superconducting generator having a stator coil having a corona shield layer on the outermost layer is arranged between the tooth portion
A superconducting generator stator part, characterized in that part of the part has semiconductivity. 14. The superconducting generator stator component according to claim 13, wherein the plate-like tooth component having semiconductivity is provided with a high elastic modulus. 15. The superconducting generator stator component according to claim 13, wherein the plate-shaped tooth component having semiconductivity is made of carbon fiber reinforced plastic. 16. The woven fabric according to claim 15, wherein the carbon fibers are laminated in an axial direction of the generator when assembled as a generator, and are aligned substantially in a radial direction and a direction perpendicular to the radial direction in a cross section perpendicular to the generator axis. A superconducting generator stator part that is characterized by 17. The semi-conductive plate-shaped tooth part component according to claim 13, wherein the plate-shaped tooth part component is made of a fiber-reinforced plastic in which a plurality of fiber woven fabrics are laminated, and at least one layer of the fiber woven fabric is a semi-conductive fiber woven fabric. Others are superconducting generator stator parts, characterized in that they are non-conductive fiber fabrics. 18. The superconducting generator stator component according to claim 17, wherein a carbon fiber woven fabric is used as the semi-conductive fiber woven fabric and a glass fiber woven fabric is used as the non-conductive fiber woven fabric.