JPH0880003A - Wound rotor coil - Google Patents

Abstract

PURPOSE: To secure the sufficient reliability to the centrifugal force to be exerted on a rotor coil of large diameter and of high circumferential speed such as one for a large variable pumped-storage power generator. CONSTITUTION: In a wound rotor where a coil straight part 14 is stored in a slot of a rotor core 11, and a coil end part 17 projecting outward of a core end part is supported and fixed by a supporting device, the radius of curvature of a corner part of a conductor of the coil end part 17 is made larger than that of the coil straight part 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine, and more particularly to a wire-wound rotor coil incorporated in a variable speed pumped-storage power generator.

[0002]

2. Description of the Related Art A variable speed pumped-storage generator employs a wire-wound rotor coil. Therefore, the wire-wound rotor coil is supported and fixed by a method different from that of an ordinary turbine generator against centrifugal force acting during operation. There is a need to.

Rotor coil 1 of a conventional variable speed pumped storage generator
As shown in FIGS. 7 and 8, the coil linear portion 3 is housed in the slot of the rotor core 2 and then fixed by a slot wedge (not shown). Further, the rotor coil end portion 4 of the rotor coil 1 protruding outward from the end portion of the rotor core 2 has a support ring 5 and a rotor coil end portion 4 connected and fixed to the end portion of the rotor core 2. An insulating spacer 6 is arranged between the rotor coil end portion 4 and the rotor coil end portion 4. Then, a bind cord 7 such as glass fiber impregnated with non-magnetic steel or thermosetting resin is wound around the outer peripheral surface of the end portion of the rotor coil end portion 4. An insulating layer 9 is provided on the outer surface of the conductor 8.

[0004]

In the rotor coil having the above-described structure, the centrifugal force acting on the rotor coil end portion 4 during operation is transmitted to the bind cord 7 via the insulating spacer 6, so that the rotor coil end is not formed. Part 4 and insulating spacer 6
Compressive stress is generated at the interface with. This compressive stress is not uniform on the outer peripheral surface of the rotor coil end portion 4, and is highest at the outer peripheral side corner portion of the cross section, and the concentration of this compressive stress is
The smaller the corner radius of the conductor 8 of the rotor coil end portion 4 is, the larger the radius is. Further, the bind cord 7 and the insulating spacer 6 after being wound are not exactly a perfect circle,
The polygonal shape inscribed on the outer peripheral surface of the rotor coil end portion 4 also contributes to the concentration of compressive stress.

If the variable speed pumped-storage generator is a large-sized variable speed pumped-storage generator with a large rotor diameter and a high peripheral speed, the centrifugal force acting on the rotor coil end portion 4 becomes large. For that reason, the insulating layer 9 applied to the corner portion of the conductor 8 of the rotor coil end portion 4 may be mechanically damaged and the electrical strength may be reduced.

The present invention has been made in view of the above points, and is sufficiently reliable against the centrifugal force acting on a rotor coil having a large diameter and a high peripheral speed such as a large variable speed pumped-storage generator. It is an object of the present invention to provide a rotor coil of a rotary electric machine that can secure the property.

[0007]

According to a first aspect of the present invention, in a wire-wound rotor coil, a coil straight portion is housed in a slot of a rotor iron core, and a coil end portion protruding outward from an iron core end portion is a supporting device. In the winding type rotor which is supported and fixed, the radius of curvature of the conductor corner portion of the coil end portion is larger than the radius of curvature of the conductor corner portion of the coil straight portion.

A winding type rotor coil according to a second aspect is the winding type rotor coil according to the first aspect, wherein a conductor having a large corner radius of curvature and a conductor having a small corner radius of curvature are connected.
Place a conductor with a large corner radius of curvature at the coil end,
It is characterized in that a conductor having a small corner radius of curvature is arranged in the coil straight portion.

According to a third aspect of the present invention, in the wound rotor coil according to the first aspect, the radius of curvature of at least the outer peripheral corner of the coil end portion conductor is larger than the conductor radius of curvature of the coil straight portion. It is characterized by being machined into.

A winding-type rotor coil according to a fourth aspect of the present invention is the winding-type rotor coil according to the first aspect, wherein among the strands forming the coil conductor, the strand corresponding to at least the outer peripheral side conductor corner portion at the coil end portion. The radius of curvature of the corner portion of is larger than the radius of curvature of the corner portion of the other wire.

[0011]

In the wire-wound rotor coil according to the first aspect of the present invention, only the conductor of the coil end portion has a larger radius of curvature than that of the conventional one so that the conductor is concentrated in the insulating layer provided on the corner portion of the conductor of the coil end portion. The compressive stress can be reduced, the reliability against damage to the insulating layer can be increased, and the space factor of the conductor in the rotor slot can be improved by keeping the corner radius of curvature of the conductor of the coil straight line as it is. Does not decrease.

In the wire-wound rotor coil according to the second aspect of the invention, since the conductor having a large corner radius of curvature is arranged only in the coil end portion, the compressive stress concentrated on the insulating layer applied to the conductor corner portion of the coil end portion is arranged. Can be reduced, and reliability against damage to the insulating layer can be improved.

In the wire-wound rotor coil according to the present invention, the coil end portion conductor is machined so that the curvature radius of at least the outer peripheral side corner portion is larger than the conductor curvature radius of the coil straight portion. The compressive stress concentrated on the insulating layer provided at the corners of the conductor can be reduced, and the reliability against damage to the insulating layer can be improved.

In the wire-wound rotor coil according to the fourth aspect of the present invention, since the radius of curvature of the corner portion of only the wire arranged on the outer peripheral side of the conductor at the coil end portion is increased, the space factor of the conductor in the rotor slot is almost the same. It is possible to reduce the compressive stress concentrated on the insulating layer applied to the corners of the conductor of the coil end without lowering the stress, and it is possible to enhance the reliability against damage to the insulating layer.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2, the same members as those in FIGS. 7 and 8 are designated by the same reference numerals.

1 to 3 show a wire-wound rotor coil according to the present invention. This wire-wound rotor coil 10 is housed in a rotor slot (not shown) provided in a rotor core 11 and supported by a slot wedge. A fixed solid conductor 12 having a small corner radius of curvature and a straight coil portion 14 composed of an insulating layer 13, and a solid conductor 15 having a large corner radius of curvature.
And the coil end portion 17 formed of the insulating layer 16 are electrically and mechanically connected in the vicinity of the slot outlet. In this way, by making the radius of curvature of the corner of the conductor 15 of the coil end portion 17 facing the insulating spacer 6 larger than that of the conventional one, stress concentration on the insulating layer 16 is relieved. Even if the insulating layer 16 is made of the same material as the conventional insulating layer, it can be applied to a rotor having a larger diameter and a higher peripheral speed. The coil straight portion 14 can also be composed of a label dislocation conductor composed of a plurality of strands.

Thus, the conductor 15 of the coil end portion 17
By making the radius of curvature of the corner portion larger than that of the conventional one, it is possible to reduce the compressive stress concentrated on the insulating layer 16 applied to the corner portion of the conductor 15 of the coil end portion 17.
The reliability against damage of can be increased. Further, by keeping the corner radius of curvature of the conductor 12 of the coil linear portion 14 as it is, the space factor of the conductor in the rotor slot does not decrease.

4 to 6 show modifications of the wound rotor coil according to the present invention. In the modifications shown in FIGS. 4 and 5, the rotor coil 10 is made of a continuous solid conductor having a small corner radius of curvature. Only the corner portions 15a of the conductor 15 corresponding to the coil end portions 17 are largely finished by machining. This machining may be performed only on the two corners on the outer peripheral side of the conductor 15a, or on all four corners on the outer peripheral side and the inner peripheral side. With such a configuration, the work of connecting conductors having two types of cross-sectional shapes can be omitted, and even an insulating layer made of the same material as the conventional one can be applied to a rotor having a larger diameter and a higher peripheral speed. it can.
By machining the corner portion 15a of the conductor 15, the cross-sectional area of the conductor of the coil end portion 17 becomes smaller than that of the coil straight portion 14, but the cooling condition of the coil end portion 17 is better than that of the coil straight portion 14, so that the temperature rises. The problem from does not arise.

In the modification shown in FIG. 6, among the plurality of strands 18 constituting the continuous label dislocation conductor 17, the corner curvature of the strand 18a arranged at least at the outer peripheral corner of the conductor of the coil end portion 17. The radius is larger than that of the other wires 18. By adopting such a configuration, the continuous label transition conductor 17 which does not require a connection work or a machining process does not significantly reduce the space factor of the conductor in the rotor slot, and the insulating layer made of the same material as the conventional material is used. By applying No. 16, a rotor coil suitable for a rotor having a larger diameter and a higher peripheral speed can be obtained.

[0021]

As described above, according to the present invention, by making the radius of curvature of the conductor corner of the coil end portion larger than the radius of curvature of the conductor corner of the coil straight portion, a large variable speed pumped storage generator can be obtained. It is possible to secure sufficient reliability even with respect to a centrifugal force that acts on a rotor coil having a large diameter and a high peripheral speed.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a wound rotor coil according to the present invention.

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

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

FIG. 4 is a cross-sectional view showing a conductor of a coil end portion of a first modified example of a wound rotor coil according to the present invention.

FIG. 5 is a sectional view showing a conductor of a coil straight portion of a first modified example of the wound rotor coil according to the present invention.

FIG. 6 is a sectional view showing a conductor of a coil end portion of a second modified example of the wire-wound rotor coil according to the present invention.

FIG. 7 is a partial cross-sectional view of a conventional wire-wound rotor coil.

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

[Explanation of symbols]

 5 Supporting Ring 6 Insulating Spacer 7 Bind Code 10 Rotor Coil 11 Rotor Iron Core 14 Coil Straight Section 15 Conductor 15a Corner of Conductor 16 Insulating Layer 17 Coil End Section

Claims (4)

[Claims] 1. A conductor of a coil end portion in a wire-wound rotor, wherein a coil straight portion is housed in a slot of a rotor core, and a coil end portion projecting outward from the core end portion is supported and fixed by a supporting device. A wound rotor coil, characterized in that a corner radius of curvature is made larger than a conductor corner radius of curvature of a coil straight part. 2. A conductor having a large corner radius of curvature and a conductor having a small corner radius of curvature are connected to each other, a conductor having a large corner radius of curvature is arranged at a coil end, and a conductor having a small corner radius of curvature is coiled. The wound rotor coil according to claim 1, wherein the wound rotor coil is arranged in a straight portion. 3. The wire-wound rotor coil according to claim 1, wherein the coil end conductor is machined so that the radius of curvature of at least the outer peripheral corner is larger than the radius of curvature of the conductor of the coil straight portion. . 4. A radius of curvature of a corner of a strand of wire constituting a coil conductor, which corresponds to at least a corner of a conductor on the outer circumference side at a coil end, is made larger than a radius of curvature of a corner of another strand. The wire-wound rotor coil according to claim 1.