JP3410881B2 - Rotor winding end support device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor winding end supporting device for supporting a rotor winding end of a large-sized rotating machine such as a variable speed pumped-storage power generator.

[0002]

2. Description of the Related Art Since a salient-pole rotor is adopted in an ordinary hydraulic turbine generator, the rotor winding is wound around a salient-pole magnetic pole that also serves as a structure, and the centrifugal force acting during operation is reduced. On the other hand, it is provided on the field pole and is restrained by the collar.

On the other hand, the AC variable speed pumped-storage power generator employs a method of AC exciting the three-phase distributed windings provided in the cylindrical rotor, so that the centrifugal force acting during operation differs from the above. The method must support the rotor windings.

FIGS. 5 and 6 show a supporting device for a rotor winding end portion in a conventional variable speed pumped-storage power generator. 5 is a side view of the rotor winding end portion, and FIG. 6 is a cross-sectional view taken along the line AA of FIG. A rotor winding 2 including an upper winding 2a and a lower winding 2b is housed in a slot of a cylindrical rotor core 1 and is fixed by a slot wedge (not shown). The rotor winding end 2c projecting outward in the axial direction from the end of the rotor iron core 1 has a U-shaped bolt 3 for tightening the rotor winding end 2c at several places in the longitudinal direction. The end portions of these U-shaped bolts 3 are connected and fixed by a nut 6 to a support ring 5 attached to the end portion of the rotor core 1 via a stay 4.

In this case, between the U-shaped bolt 3 and the upper winding 2a of the rotor winding end 2c, between the upper winding 2a and the lower winding 2b, and between the rotor winding end 2c. Lower winding 2b
Insulating blocks 7a, 7b, and 7c are provided between the support ring 5 and the support ring 5 to ensure insulation strength according to the winding voltage so as to prevent discharge of metal structures at ground potential. .

In the rotor winding end supporting device having such a structure, the centrifugal force acting on the rotor winding end 2c during operation is transmitted to the supporting ring 5 via the U-shaped bolt 3. Therefore, if the rigidity of the support ring 5 is sufficiently large, the deformation of the rotor winding end portion 2c in the outer diameter direction can be suppressed to an extremely small value.

[0007]

Generally, as the size of the variable speed pumped storage generator becomes larger, the exciting voltage of the rotor winding 2 becomes higher. At such a high-voltage rotor winding end 2c, the potential difference from the U-shaped bolt 3 having a ground potential becomes large. Therefore, in order to increase the insulation strength, the rotor winding ends 2c structurally adjacent to each other are increased. It is necessary to increase the interval.

However, in order to widen the space, the rotor winding end portion 2c must inevitably be lengthened, and the structure for supporting this also becomes inconvenient. From this, Japanese Patent Application Laid-Open No. 6-292336 discloses a technique of providing the insulating layer 8 on at least a portion of the U-shaped bolt 3 facing the side surface of the rotor winding end 2c as shown in FIG. There is. In this case, in order to increase the insulation strength, a groove is provided in each insulating block 7, and the insulating block 8 and the insulating layer 8 of the U-shaped bolt 3 are assembled and integrated with each other.

However, the overlapping margin between the insulating layer 8 of the U-shaped bolt 3 and each insulating block 7 is restricted by the radial thickness of the insulating block 7. In particular, if the insulating block 7a on the outermost diameter side is made thicker, the gap between the U-shaped bolt 3 and the stator winding (not shown) is narrowed, which is inconvenient.

An object of the present invention is to ensure the insulation strength required at the end of a high voltage rotor winding such as a large variable speed pumped-storage generator without increasing the length of the rotor winding end. An object of the present invention is to provide a support device for a rotor winding end portion.

[0011]

According to a first aspect of the present invention, there is provided a rotor winding formed by projecting an upper winding and a lower winding axially outward from an end portion of a cylindrical rotor core. A rotor winding end portion for supporting the wire end portion, the support ring attached to a stay provided so as to project axially outward from the rotor core end portion, and the rotor winding end portion. A U-shaped bolt having an insulating layer provided on a portion corresponding to a side surface of the rotor winding end fixed to the support ring by sandwiching a portion between the U-shaped bolt and the rotor winding end. Between the upper winding,
An insulating block provided between the upper winding and the lower winding of the rotor winding end, and between the lower winding of the rotor winding end and the support ring, respectively. In the supporting device for the rotor winding end portion, a U-shaped insulating barrier is provided so as to cover the surface of the upper winding on the U-shaped bolt top side and the side surface of the upper winding in contact with the surface. Is characterized by.

According to the invention of claim 1, the insulating layer of the U-shaped bolt, the insulating block provided between the U-shaped bolt and the upper winding of the rotor winding end, and the rotor winding end are provided. Since the U-shaped insulation barrier provided between the upper winding and the upper winding improves the insulation strength required for the rotor winding, it is also adjacent to the rotor winding of the high-voltage variable speed pumped-storage generator. Without increasing the distance between the rotor winding ends,
It is possible to secure sufficient reliability.

According to a second aspect of the present invention, in the first aspect of the present invention, an insulating block provided between the lower winding of the rotor winding end portion and the support ring and a lower portion of the rotor winding end portion are provided. A U-shaped insulating barrier is additionally provided between the side winding and the side winding.

According to the invention of claim 2, in addition to the operation of claim 1, an insulating block provided between the insulating layer of the U-shaped bolt, the lower winding of the rotor winding end and the support ring. Since the U-shaped insulation barrier provided between the rotor winding and the lower winding of the rotor winding end improves the insulation strength required for the rotor winding, Even with respect to the rotor winding, sufficient reliability can be ensured without increasing the interval between the adjacent rotor winding end portions.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. 1 is a side view of a rotor winding end supporting device according to a first embodiment of the present invention, and FIG. 2 is an AA line of FIG.
It is a sectional view taken along the line. The first embodiment is different from the conventional example shown in FIGS. 5 and 6 in that the insulating layer 8 is provided on the portion corresponding to the side surface portion of the rotor winding end portion 2c of the U-shaped bolt 3, Block 7a and rotor winding end 2c
The insulating barrier 10 is provided between the upper winding 2a and the upper winding 2a.

1 and 2, the upper winding 2a and the lower winding 2b of the rotor winding 2 are housed in slots (not shown) provided in the rotor core 1, and are supported and fixed by slot wedges. There is. A support ring 5 is attached to the end of the rotor core 1 via a stay 4 on the inner diameter side of the rotor winding end 2c.

Further, a U-shaped bolt 3 for tightening the rotor winding end 2c is provided at a plurality of positions in the longitudinal direction of the rotor winding end 2c so as to sandwich the rotor winding end 2c, and the end is supported by a nut 6. It is fastened and fixed to each ring 5. In this case, between the U-shaped bolt 3 and the upper winding 2a, the upper winding 2
Insulating blocks 7a and 7b are provided between a and the lower winding 2b and between the lower winding 2b and the support ring 5, respectively.
7c is inserted.

Then, an insulating tube made of FRP is inserted into the portions of the U-shaped bolt 3 corresponding to the side surfaces of the upper winding 2a and the lower winding 2b, and an insulating layer 8 is formed, and then assembled. To do. At this time, in order to increase the insulation strength, each insulation block 7
Grooves 9 are provided in a, 7b and 7c as shown in FIG.
FIG. 3 is a sectional view taken along the line BB of FIG.

As can be seen from FIG. 3, each insulating block 7
The insulating layer 8 of the U-shaped bolt 3 is assembled in the groove 9 of a, 7b, and 7c so as to overlap with each other.
A U-shaped insulating barrier 10 made of FRP is inserted between the upper winding 2a and the upper winding 2a.

According to the first embodiment, the insulation strength between the rotor winding end 2c and the U-shaped bolt 3 is U, which is interposed between the insulating block 7a and the upper winding 2a. Due to the effect of the V-shaped insulation barrier 10, the insulation strength between the U-shaped bolt 3 having only the insulation layer 8 and the rotor winding end portion 2c becomes higher, so that the rotor winding 2 can be made higher in voltage. However, it is not necessary to increase the distance between the adjacent rotor winding end portions 2c as in the conventional case. At this time, the longitudinal dimension and the radial dimension of the rotor winding 2c of the U-shaped insulation barrier 10 are adjusted according to the voltage of the rotor winding 2.

Next, FIG. 4 shows a second embodiment of the present invention. The second embodiment is provided between the lower winding 2b of the rotor winding end 2c and the support ring 5 in comparison with the first embodiment shown in FIGS. Between the insulating block 7c and the lower winding 2b of the rotor winding end 2c,
The insulation barrier 10 is additionally provided.

That is, in the second embodiment, the U-shaped insulating barrier 10 is arranged between the insulating block 7c and the lower winding 2c in addition to the position of the first embodiment, It is possible to reduce the thickness dimension of the insulating block 7c.

[0023]

As described above, according to the present invention, even in a high-voltage rotor winding such as a large-sized variable speed pumped-storage generator, the length of the rotor winding end is minimized. In addition, it is possible to provide a support device for the rotor winding end portion that can secure sufficient insulation strength.

That is, since the insulation strength required for the rotor winding is improved by the insulating layer of the U-shaped bolt and the U-shaped insulation barrier provided between the insulating block and the rotor winding, the variable voltage pumping of high voltage is performed. Even for the rotor winding of the generator, sufficient reliability can be ensured without increasing the distance between the adjacent rotor winding ends.

[Brief description of drawings]

FIG. 1 is a side view of a rotor winding end portion showing a first embodiment of the present invention.

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

FIG. 3 is a sectional view taken along the line BB of FIG.

FIG. 4 is a side view of a rotor winding end portion showing a second embodiment of the present invention.

FIG. 5 is a side view of a rotor winding end portion showing a conventional example.

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

FIG. 7 is a cross-sectional view of a rotor winding end portion showing another conventional example.

[Explanation of symbols]

1 rotor core 2 rotor winding 2a Upper winding 2b Lower winding 2c Rotor winding end 3 U-shaped bolt 4 stay 5 Support ring 6 nuts 7 Insulation block 7a Outer diameter side insulation block 7b Intermediate insulation block 7c Inner diameter side insulation block 8 U-shaped bolt insulation layer 9 grooves 10 Insulation barrier

Claims (2)

(57) [Claims] 1. A rotor winding for supporting a rotor winding end formed by projecting an upper winding and a lower winding axially outward from an end of a cylindrical rotor core. At the end of the line,
A support ring attached to a stay provided so as to project axially outward from the rotor core end and a rotor winding end fixed to the support ring by sandwiching the rotor winding end. U provided with an insulating layer on the side surface
A V-shaped bolt, between the U-shaped bolt and an upper winding of the rotor winding end, between an upper winding and a lower winding of the rotor winding end, and the rotor winding A support device for an end portion of a rotor winding comprising an end lower winding and an insulating block respectively provided between the support ring, a surface of the upper winding on a top side of the U-shaped bolt, and A supporting device for a rotor winding end portion, wherein a U-shaped insulating barrier is provided so as to cover a side surface of the upper winding in contact with the surface. 2. The U-shaped insulating barrier is provided so as to cover a surface of the lower winding on the bottom side of the U-shaped bolt and a side surface in contact with the surface. Support device for child winding end.