JP2529953B2 - Rotor coil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to the structure of a rotor coil of a rotary electric machine, and in particular, avoids stress concentration in the insulation of the coil end portion of high voltage and large current used for AC excitation. In addition, the present invention relates to a structure of a coil end portion which is favorable for improving the reliability of insulation.

[Conventional technology]

The coil end portion of the conventional wire-wound rotor is provided with binding means such as winding a bind wire in order to support and restrain the coil end. In this case, when it becomes a rotor of a large-capacity rotating electric machine, the winding amount of the bind also increases, and the winding space of the bind becomes a problem.

Generally, the wire conductor of the rotor coil is a combination of wire conductors of the same size both inside and outside the iron core slot, so that, for example, Japanese Utility Model Publication No. 57-139250 and Japanese Utility Model Publication No. 60-177649 are used. As described in the official gazette, bend it to the inner diameter side so that there is a step on the coil end part outside the slot,
A space for binding for support restraint is secured with the slot depth minimized.

[Problems to be solved by the invention]

However, in the rotor coil formed in this way, the cross section of the rotor coil becomes large due to the large capacity and high voltage of the rotating electrical machine, and when high voltage insulation is required, the slot due to centrifugal force during operation is The stress caused by the difference in coil displacement between the end part and the end part, and because the coil end part is supported and restrained by binding, the bending stress due to thermal expansion and contraction of the coil that occurs during start and stop etc. significantly increases the insulation life of the bent part. There was a drawback of shrinking.

The present invention has been made in view of this, and an object thereof is to bend the coil end portion due to thermal expansion and contraction of the coil even if the rotating electric machine has a large capacity and a high voltage and the cross section of the rotor coil becomes large. It is an object of the present invention to provide a rotor coil of this kind which has a reduced stress level and does not shorten the life of insulation of the coil end portion.

[Means for solving problems]

That is, the present invention is a rotor coil in which a plurality of core wire conductors in a core slot of a wound rotor are labeled and transposed, and a coil end portion outside the slot is provided with binding means for supporting and restraining the coil end, The coil end portion is formed of a solid bar, and the solid bar is formed in a shape having the same outer shape as the wire conductor on the iron core slot end side and a smaller cross-sectional shape on the coil end tip side. The wire conductor is formed in a cross section so as to be joined and integrated in the vicinity of the exit of the core conductor slot to achieve the intended purpose.

Further, in this case, the joining position of the solid bar and the wire conductor is located at the center between the end of the iron core slot and the end of the bind on the iron core slot side.

Further, in a rotor coil in which a plurality of wire conductors in slots of a wound-rotor are label-dislocated and a bind wire for supporting and restraining the coil end is wound around a coil end portion outside the slot, The section is formed by a solid bar with a modified cross section in which only the outer diameter side is marked to reduce the radial conductor height, and this solid bar is connected to the strand conductor at the center between the slot end and the bind wire end. It is designed to be joined and integrated.

[Action]

That is, in the rotor coil thus formed, since the coil end portion is formed of the solid bar, that is, the space factor of the conductor through which the current passes in the slot inner cross section of the rotor coil is It is about 80% when the space dimension required for conductor insulation and label dislocation is added, and the space of this difference can be obtained by forming a solid bar at the coil end portion, and this space can be used as the winding space for the bind wire. In addition, it is not necessary to bend or bend the coil end portion as in the conventional case. Therefore, even if the cross section of the rotor coil becomes large, the bending stress level of the coil end portion due to thermal expansion and contraction of the coil, etc. And the life of the insulation of the coil end portion is not shortened.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. The rotor coils 1 and 2 are composed of a plurality of strand conductors 1a, are mounted in the slots of the rotor core 3 via the intermediate layer 8, and are supported and fixed by the wedge 6 via the filler 7. As for the end portion outside the iron core slot, the rotor coil 2 in the lower stage is arranged via the cushioning material 12 with respect to the coil holding ring 5 connected to the end duct 4, and the bind 9 is wound and supported and restrained. Furthermore,
The upper rotor coil 1 is also supported and restrained by winding the bind 10 around it.

In addition, for the binds 9 and 10, the insulating layer 11 is provided so as to absorb the irregularities of the adjacent coils,
It protects the coil insulation layer 1C.

For example, in a three-phase field coil of a wound rotor of a large capacity variable speed generator of 300MVA400RPM class, about 1000
Because it is exposed to the high centrifugal force of G, the end portion of the rotor coil that has high voltage insulation with a cross-sectional dimension similar to that of a conventional stator coil of a generator of the same scale is supported and restrained by a multi-layer winding bind. There is a need. Further, in the binding, it is necessary in design to wind the rotor coil end portions of the lower stage and the upper stage, respectively.

Wire conductors in iron core slots of rotor coils 1 and 2
1a is label-dislocated, and the coil end portion outside the iron core slot is formed by a solid bar 1b. The solid bar 1b and the label-dislocated strand conductor 1a are joined and integrated near the outlet of the iron core slot by, for example, brazing or welding.

With the rotor coil formed in this way, the space factor of the conductor through which the current flows in the cross section of the slot is 80% when the space dimension required for insulation of the wire conductor and label dislocation is added.
Since it is the position, the cross-sectional area of the solid bar may also be that size, and thus the space of this difference can be used as the bind wire winding space, and the coil end part can be bent,
There is no need to bend it. Since the coil end is straight without being bent, even if the rotor coil has a large cross section, the stress level at the coil end due to thermal expansion and contraction of the coil is low, and the coil end is not It does not shorten the life of the existing insulation.

In this case, the binding space can be further increased by the following method. That is, for this rotor coil 1, if the cross-sectional area of the plurality of insulated wire conductors 1a in the slot is 100% and the height is 80 mm, the space factor of the portion through which the current passes is, for example, 80%. Is. Therefore, the coil end is the same as the width of the conductor in the slot, and the height dimension in the binding range is 64% of 80% so that only the outer diameter side has a paragraph. Solid bar with irregular cross section with reduced dimensions
1b is joined and integrated by brazing or welding at the center of the slot end of the rotor core 3 and the end of the bind 9 or 10 (on the side of the core slot). In this case, of course, the rotor coil 2 has the same dimensions as the rotor coil 1.

According to the present embodiment, since the coil end portion has a space for winding the bind of 20% of the conductor height of the coil in the slot 16 mm on the outer diameter side of the coil, the wedge lower filler 7 and the middle interlayer 8 in the slot are formed. Even when the dimensions of the coil are minimized, that is, the slot depth is minimized, it is possible to form a coil shape in which stress concentration does not occur at a specific position of the coil end portion. Since the coil end portion does not have to be bent and bent, the finished dimensional accuracy of the coil end portion can be easily improved.

Further, since the joining position of the wire conductor 1a and the solid bar 1b is performed at the center of the iron core slot end and the binding end, the stress at the joining point of the wire conductor can be minimized. That is, since a neutral point at which the stress direction is reversed appears at the center of the slot end and the binding end, the stress at the joining point of the wire conductor can be minimized by joining at this point.

It should be noted that even when a machine having a small centrifugal force such that it is necessary to wind the bind only on the upper rotor coil 1 or a bind means such as a retaining ring is used to support the coil end portion, the same is obtained by adopting the present invention. The effect of is obtained.

〔The invention's effect〕

As described above, according to the present invention, even if the rotating electric machine has a large capacity and a high voltage and the cross section of the rotor coil is large, the bending stress level of the coil end portion is not lowered due to thermal expansion and contraction of the coil. It is possible to obtain this kind of rotor coil that does not come apart and does not shorten the insulation life of the coil end portion.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a main part of a wire-wound rotor provided with a rotor coil according to an embodiment of the present invention. 1 ... Rotor coil, 1b ... Solid bar, 2 ... Rotor coil, 3 ... Rotor core, 4 ... End duct.

Claims (3)

(57) [Claims] 1. A rotor coil in which a plurality of core conductors in a core slot of a wire-wound rotor are label-displaced and binding means for supporting and restraining the coil end is provided at a coil end portion outside the slot, The coil end portion is formed of a solid bar, and the solid bar is formed in a shape having the same outer shape as the wire conductor on the iron core slot end side and a smaller cross-sectional shape on the coil end tip side. A rotor coil formed in a cross section so as to be joined and integrated with the wire conductor near the outlet of the iron core slot. 2. The rotor coil according to claim 1, wherein a joining position of the solid bar and the wire conductor is a center between an end portion of the iron core slot and an end portion of the bind on the iron core slot side. . 3. A rotor coil in which a plurality of strand conductors in a slot of a wire-wound rotor are labeled and transposed, and a bind wire for supporting and restraining the coil end is wound around a coil end portion outside the slot, The coil end portion is composed of a solid bar having a modified cross section in which only the outer diameter side is marked to reduce the radial conductor height, and the solid bar is formed at the center between the slot end and the bind wire end. A rotor coil characterized by being joined and integrated with a wire conductor.