JPH0515100A - End structure for rotor winding - Google Patents

Abstract

PURPOSE:To obtain a sufficient insulation performance against a centrifugal force to be operated at winding ends of a rotor by so disposing an insulating position of an electric connector between a plurality of upper and lower coils as not to be superposed with a coil supporting point of a rotor winding clamping element, and insulating it after an electric connection. CONSTITUTION:Centrifugal forces to be operated at ends of a rotor winding 2 are all so transmitted to a support ring 6 through a U-bolt 4 disposed as not to be superposed with an insulating position of an electric connector 8. An insulator 8a of the connector 8 can perform sufficient insulation performance without receiving any mechanical force from the bolt 4. An insulator 9b of the connector 8 at the longitudinal foremost end of the upper coil 2a of the winding 2 is impregnated in vacuum with thermosetting resin and sufficiently cured to be molded, and hence mechanical strength, insulation durability are sufficient as compared with the insulator 9a of the connector 9, and the position of the bolt 4 at the outermost end can be sufficiently approached to the end of the winding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the end structure of a rotor winding for a large rotating electric machine such as a variable speed pumped storage generator.

[0002]

2. Description of the Related Art Usually, in a turbine generator, salient pole type rotors are often used. Therefore, the rotor windings are wound around salient pole field poles that also serve as structures, and they act during operation. The rotor winding is restrained by the collar provided on the field pole against the centrifugal force. On the other hand, in the AC variable speed pumped-storage generator, since the method of AC exciting the three-phase distributed winding housed in the slot on the surface of the cylindrical rotor is adopted,
The constraint of the rotor winding against the centrifugal force that acts during operation is
It was necessary to use a method different from the above. From this,
In the rotor winding of the conventional variable speed pumped-storage generator, the portion housed in the rotor core is fixed by the slot wedge, and the portion protruding outward from the end of the rotor core is as shown in FIG.
A bind cord such as glass fiber impregnated with non-magnetic steel or thermosetting resin is wound around the outer peripheral surface while applying tension to support and fix it. In FIG. 6, 1 is a bind cord, 2 is a rotor winding, 3 is an insulating block, 5 is a rotor core, 6 is a support ring, 7 is a stay, 9a is a connection part insulation, and 9b is insulation other than the connection part. Shown respectively.

By the way, in such a method of supporting and fixing the winding, the bind cord 1 is provided especially on the outer circumference of the end portion of the rotor winding 2.
In order to wind, the rolling device for rotating the generator rotor, the feeding device for the bind cord 1, the constant tension device for applying a constant tension to the bind cord 1, and the like are required. Further, in the case of a rotor of a large-sized variable speed pumped storage power generator having a diameter of more than 5 m, it is often assembled on site due to transportation restrictions. In this case, the rolling device, the bind cord sending device, It is difficult to use a tension device or the like.

Therefore, recently, as a method of supporting and fixing the end portion of the rotor winding 2 on site without using the above-described devices, for example, FIGS. 7 and 8 (A- in FIG. 7).
There is a method as shown in FIG. That is, in FIG. 7 and FIG. 8, the end portion of the rotor winding 2 has U-shaped fastening bolts (hereinafter referred to as U bolts) that are rotor winding fastening elements at several points in the longitudinal direction thereof via the insulating block 3. ) 4 is connected and fixed to a support ring 6 which is connected and fixed to the end of the rotor core 5. Also, U bolt 4
In some cases, as a rotor winding fastening element instead of the above, a loop tie (not shown) made of glass fiber impregnated with a thermosetting resin is coupled and fixed to the support ring 6.

By the way, in such a method of supporting and fixing the winding, the centrifugal force acting on the end portion of the rotor winding 2 is transmitted to the support ring 6 through the U bolt 4 during operation. In this case, as the position of the U-bolt 4 at the outermost end, it is effective to bring the U-bolt 4 as close as possible to the tip of the winding end portion, whereby the deformation of each portion of the winding end portion in the outer diameter direction is suppressed to an extremely small value. be able to. However, as shown in the sectional view of FIG. 9, the rotor winding 2 as shown in FIG. 7 is separately insulated from the upper coil 2a and the lower coil 2b, and is housed in a rotor slot (not shown). , Electrical connections 8 are made at both ends. Therefore, the insulation 9 of the electrical connection portion 8
a is to be carried out after assembling in the field, and has mechanical strength as compared with the other insulation 9b which can be sufficiently cured by vacuum impregnation with a thermosetting resin in a factory.
It cannot be denied that the dielectric strength is also poor. On the other hand, for the above-mentioned reason, when the position of the outermost U-bolt 4 is made to approach the end of the winding end, the insulation 9a of the electric connection portion 8 is caught. As described above, the insulation 9a of the electrical connection portion 8
Since the mechanical strength and the dielectric strength are inferior to the insulation 9b of the other parts, the rotor winding is large in a large rotary electric machine such as a variable speed pumped-storage generator having a large rotor diameter and a high peripheral speed. Two
The insulation 9a of the electrical connection portion 8 below the outermost U-bolt 4 may be mechanically damaged by the centrifugal force acting on the, and the insulation performance may be significantly reduced.

[0006]

As described above, in the end structure of the rotor winding of the conventional large-sized rotating electric machine, the insulation of the electrical connection portion is mechanically damaged and the insulation performance is remarkably deteriorated. There was a problem to do.

An object of the present invention is to assemble on-site which can ensure a sufficient insulation performance against centrifugal force acting on a winding end portion of a rotor of a large rotating electric machine such as a variable speed pumped-storage generator. It is an object of the present invention to provide an extremely reliable rotor winding end structure suitable for.

[0008]

In order to achieve the above object, according to the present invention, a support ring is attached and fixed to an end of a rotor core via a stay, and an end of a rotor winding is provided on an outer periphery of the support ring. A plurality of rotor winding fastening elements that are passed through between the parts and fastened to the rotor winding are attached and fixed, and an electrical connection portion between a plurality of upper coils and lower coils that form the rotor winding is attached. The electric connection portion is arranged so that the insulation position does not overlap the coil support point of the rotor winding fastening element, and the electric connection portion is electrically connected and then insulated.

[0009]

Therefore, in the rotor winding end structure of the present invention, the rotor winding is arranged so that all centrifugal forces acting on the rotor winding end do not overlap the insulating position of the electrical connection. By being transmitted to the supporting ring through the wire fastening element, it is not necessary to support the rotor winding end through insulation of the electrical connection part, which has poor mechanical strength and dielectric strength compared to other parts, and the winding end is eliminated. The reliability of the entire unit can be significantly improved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 are views respectively showing structural examples of the end structure of a rotor winding according to the present invention. In addition,
1 and 2, the same elements as those of FIGS. 6 to 9 are denoted by the same reference numerals.

In FIGS. 1 and 2, the rotor winding 2 housed in a rotor slot (not shown) provided in the rotor core 5 is supported and fixed by a slot wedge (not shown) at the core portion. Further, on the inner diameter side of the rotor winding 2 protruding from the end of the rotor core 5, a support ring 6 is attached and fixed to the end of the rotor core 5 via a stay 7. Further, on the outer periphery of the support ring 6, a plurality of (three in the figure) for inserting between the ends of the rotor winding 2 and fastening the rotor winding 2 through the insulating block 3 are provided. A U-bolt 4 which is a rotor winding fastening element is attached and fixed by a nut 10.

On the other hand, in the rotor winding 2, the upper coil 2a and the lower coil 2b are separately insulated in advance, and they are electrically connected after they are housed in a rotor slot (not shown). As shown in FIG. 2, the lower coil 2b is shortened to be closer to the rotor core 5 side and is provided substantially in the center between the U bolts 4 adjacent in the longitudinal direction. That is, in the electrical connection portion 8, the insulation position of the electrical connection portion 8 between the plurality of upper coils 2a and the lower coil 2b that form the rotor winding 2 does not overlap with the coil support point of the U bolt 4. Are arranged as follows. Further, the electrical connection portion 8 is electrically connected and then subjected to insulation 9a on site, and then tension is applied to the nut 10 to eliminate slack, thereby supporting the end portion of the rotor winding 2.

Next, in the end structure of the rotor winding configured as described above, all centrifugal forces acting on the end of the rotor winding 2 do not overlap with the insulating position of the electrical connecting portion 8. It is transmitted to the support ring 6 through the U bolt 4 arranged at. Therefore, the insulation 9a of the electrical connection portion 8 can exert sufficient insulation performance without receiving any mechanical force from the U bolt 4. Further, the insulation 9b at the most distal end of the upper side coil 2a of the rotor winding 2 in the longitudinal direction can be sufficiently hardened by vacuum impregnation with a thermosetting resin in advance at the factory. The mechanical strength and dielectric strength are satisfactory in comparison with the above, and it is possible to bring the position of the U-bolt 4 at the outermost end sufficiently close to the tip of the winding end. The deformation can be suppressed to an extremely small level. As a result, the reliability of the entire winding end portion can be significantly improved as a result.

As described above, the end structure of the rotor winding of this embodiment has the end portion of the rotor core 5 on the inner diameter side of the rotor winding 2 protruding from the end portion of the rotor core 5. The support ring 6 is attached and fixed to the support ring via the stay 7.
A plurality of (three) rotor winding fastening elements for passing between the ends of the rotor winding 2 around the outer periphery of the rotor winding and fastening the rotor winding 2 through the insulating block 3 to the rotor winding 2. The bolt 4 is attached and fixed by the nut 10, and the electrical connection portion 8 between the upper coil 2a and the lower coil 2b forming the rotor winding 2 is connected.
The electrical connection portion 8 is arranged so that the insulation position thereof does not overlap the coil support point of the U-bolt 4, and after the electrical connection portion 8 is electrically connected, the insulation 9a is applied on site.

Therefore, all the U bolts 4 are connected to the electrical connection 8
It can be arranged at a position where it does not overlap the insulation position of No. 1 and the deformation of the winding end portion due to centrifugal force can be suppressed to an extremely small level. As a result, the centrifugal force acting on the end portion of the rotor winding 2 during operation is U only through the insulating portion which has been sufficiently hardened by vacuum impregnation with the thermosetting resin in the factory.
It is transmitted to the bolt 4. For this reason, it becomes possible to secure sufficient insulation performance against centrifugal force acting on the winding end portion of the rotor of a large rotating electric machine such as a variable speed pumped-storage generator.
The reliability of the winding end as a whole can be greatly improved, making it extremely suitable for on-site assembly. The present invention is not limited to the above embodiment, but can be implemented in the same manner as described below.

(A) As shown in FIG. 3, the upper coil 2a
Is shortened to bring the electric connection portion 8 closer to the rotor core 5 side and to provide the electric connection work and the insulation work of the electric connection portion 8 to the outside of the rotor by providing the electric connection portion at the substantially central portion between the U bolts 4 adjacent in the longitudinal direction. Since it can be performed from the radial side, the assembling work is easier than in the above-described embodiment.

(B) As shown in FIG. 4, a loop tie 11 made of glass fiber impregnated with thermosetting resin is used in place of the U-bolt 4 as a rotor winding fastening element, and is fixedly coupled to the support ring 6. By doing so, since the loop tie 11 before heat curing is flexible, it is possible to assemble even if the winding end structure has lower dimensional accuracy than the U bolt 4 according to the above-described embodiment.

(C) As shown in FIG. 5, the upper coil 2a
Also, the tip of the end of the lower coil 2b is bent to the inner diameter side to form an L-shaped structure, and the electric connection portion 8 is a portion of the rotor winding 2 that is perpendicular to the rotor shaft (not shown) (the outermost end in the axial direction). In this case, since the portion has the largest distance from the adjacent coil in the rotor circumferential direction in the winding end portion, the insulating work space is wide, and the assembling work is easier than in the case of FIG. ..

[0020]

As described above, according to the present invention, the support ring is attached and fixed to the end of the rotor core through the stay, and the end of the rotor winding is passed through the outer periphery of the support ring. Then, a plurality of rotor winding fastening elements that are fastened to the rotor winding are attached and fixed, and the insulation position of the electrical connection between the plurality of upper coils and the lower coil that form the rotor winding is determined by the rotor. Since the electrical connection portion is arranged so as not to overlap the coil supporting point of the winding fastening element and the electrical connection portion is electrically connected and then insulated, it is possible to prevent the rotor of a large-sized rotating electric machine such as a variable speed pumped-storage generator from being insulated. It is possible to provide an extremely reliable rotor winding end structure suitable for field assembly, which can ensure sufficient insulation performance against centrifugal force acting on the winding end.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an end structure of a rotor winding according to the present invention.

FIG. 2 is a diagram showing an embodiment of an end structure of a rotor winding according to the present invention.

FIG. 3 is a diagram showing another embodiment of the rotor winding end structure according to the present invention.

FIG. 4 is a view showing another embodiment of the end structure of the rotor winding according to the present invention.

FIG. 5 is a diagram showing another embodiment of the rotor winding end structure according to the present invention.

FIG. 6 is a diagram showing an example of an end structure of a rotor winding of a conventional variable speed pumped storage generator.

FIG. 7 is a diagram showing an example of an end structure of a rotor winding of a conventional variable speed pumped-storage generator assembled in the field.

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

FIG. 9 is a cross-sectional view showing an example of a method of insulating a rotor winding of a conventional variable speed pumped-storage generator.

[Explanation of symbols]

1 ... Bind cord, 2 ... Rotor winding, 2a ... Upper coil, 2b ... Lower coil, 3 ... Insulating block, 4 ... U bolt, 5 ... Rotor core, 6 ... Support ring, 7 ... Stay, 8
... electrical connection part, 9 ... rotor winding insulation, 9a ... connection part insulation, 9b ... insulation other than connection part, 10 ... nut, 11 ... loop tie.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hirokazu Kaneko 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Within Tokyo Electric Power Company (72) Inventor Katsuhiko Yoshida 2-4, Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Toshiba Corporation Keihin Office

Claims (1)

Claim: What is claimed is: 1. A support ring is attached and fixed to an end of a rotor core via a stay, and the end of the rotor winding is passed through the outer periphery of the support ring. A plurality of rotor winding fastening elements that are fastened to the windings are attached and fixed, and an insulating position of an electrical connection portion between a plurality of upper coils and a lower coil that form the rotor winding is the rotor winding. An end structure of a rotor winding, wherein the electric connection portion is arranged so as not to overlap a coil supporting point of a fastening element, and the electric connection portion is electrically connected and then insulated.