JPH0817551B2 - Superconducting rotating electric machine stator - 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 rotary electric machine, and more particularly to a cooling structure for an armature core having a gap armature winding.

[0002]

2. Description of the Related Art In a superconducting generator or the like, an air gap electric machine in which an armature winding is arranged in an air gap between a rotor and a stator core in order to reduce mechanical dimensions and increase output density. The child winding is adopted. The air gap armature winding is fixedly supported by a stator core provided on the stator side by some method. Regarding the winding support method of the air gap armature winding method, U.S. Pat. No. 3,405,297 or Japanese Patent Publication No. 3-2.
No. 4139 is disclosed.

The rotor of the rotating electric machine having such a structure is provided with a field winding in a cylindrical rotor container and cooled by a coolant such as liquid helium. The air gap armature winding provided on the stator side employs a cooling system in which a cooling pipe is provided in a coil forming the winding and a cooling medium is directly fed into the cooling pipe. Furthermore, the magnetic shield (stator core) is provided which is constructed by laminating thin iron plates in order to shield the magnetic flux <br/> generated by the field winding in the stator side. In the stator core, the magnetic flux generated by the field winding is linked and loss occurs. For this reason, it is necessary to consider a cooling method that is different from that of the rotor or air gap armature winding.The stator core is divided in the stacking direction, and a cooling member with good thermal conductivity is inserted between the divided stator cores. A method of indirectly cooling the stator core has been considered.

By the way, since the cooling member inserted between the stator cores is generally highly conductive at the same time as being electrically conductive, the magnetic flux produced by the field windings is linked with the stator core, resulting in loss. appear. At the same time the loss caused to concentrate on the inner circumferential surface of the cooling member which is inserted between the stator core, the magnetic flux of the cooling member vicinity because of the complex distributed reasons gap armature winding support structure, the cooling member On the inner peripheral surface, there is a portion where a concentrated loss occurs even in the circumferential direction. Therefore, the cooling member may cause local overheating and stop the rotating electric machine.

[0005]

By the way, since the cooling member inserted between the stator cores is generally highly conductive at the same time as being conductive, loss occurs due to the interlinking magnetic flux as described above. The magnetic flux distribution in the vicinity of the cooling member is complicated, and induced currents in the circumferential direction of the inner peripheral surface are concentrated, so that the loss is concentrated on the inner peripheral surface. For this reason, there is a possibility that the cooling member may cause local overheating and cause serious problems such as stopping the operation of the rotating electric machine.

An object of the present invention is to limit the induced current concentratedly generated in the inner peripheral portion of the cooling member to reduce local overheating, and at the same time reduce the loss in the cooling member.

[Contents of correction]

[0007]

In order to achieve the above-mentioned object , a space is provided around the outer circumference of a cylindrical superconducting rotor.
And a concentric cylindrical stator, the stator
Is the cylindrical stator core and the inner peripheral surface side of this stator core.
Having a cylindrical stator winding supported by
I do. The stator winding encloses the coils, cooling tubes, and
Having a cylindrical support member that surrounds and supports the stator core
Is a plurality of thin iron plates laminated in the axial direction and the suitability of this laminated body.
A cooling member that is inserted and arranged at an appropriate point, and this cooling member
Having a flow path for a cooling medium provided inside
And The laminated body of the thin iron plate of the stator core and the cooling member is
Has a plurality of fixing grooves that are formed along the axial direction on the inner peripheral surface of the
Shall be done. The support member of the stator winding is
Fixing groove of laminated body of thin iron plate of stator core and cooling member on the peripheral surface
Has a ridge that fits into the fixed groove.
And support the stator winding on the stator core. Of the stator core
The cooling member has a shape that corresponds to the shape of the thin iron plate,
Inner surface formed of conductive and conductive material
It has a narrow groove along the axial direction. in this case,
The narrow groove of the cooling member of the stator core is located at the bottom and top of the fixed groove.
It is preferably formed on at least one side. Also, above
Compatible with thin iron plate shapes instead of the stator core cooling member
With the shape, the part with the fixing groove is an insulator,
The other part is made of a material having good thermal conductivity and conductivity.
It is formed physically and along the axial direction on the inner peripheral surface of other parts
It may have a narrow groove. Also in this case,
The narrow groove of the cooling member of the stator core is located at the bottom and top of the fixed groove.
It is preferable to form at a position corresponding to at least one
Yes.

[0008]

By providing the axial narrow groove on the inner peripheral surface of the cooling member, the electric current flowing through that portion can be blocked. As a result, the induced current concentrated on the inner peripheral portion of the cooling member is limited, which reduces local overheating and reduces loss in the cooling member. The number of the narrow grooves increases as the number of magnetic fluxes generated by the field winding and the cooling member increases, thereby limiting the induced current concentrated on the inner peripheral portion of the cooling member. . Therefore, the criterion for setting the narrow groove is selected according to the flux linkage amount.

When the fixed groove is provided on the cooling member, the interlinkage magnetic flux at the bottom of the fixed groove is smaller than that at the top of the fixed groove, and the cooling effect of the cooling medium flowing inside the cooling member is greater at the bottom of the fixed groove. The fixed groove top fine groove has a larger effect of local heating relaxation by setting the fine groove. The fixed groove top fine groove has a larger loss reduction effect.

Attaching the fixed groove member of the insulator has the effect of lowering the magnetic flux density on the inner peripheral surface of the cooling member, and since the inner circumference is circular, the effect of reducing the induced current in the narrow groove is large, and the inside of the cooling member is large. Since the cooling effect of the cooling medium flowing through is also great, the local overheating mitigation effect is great. The higher magnetic flux density is the insulator, and the amount of loss reduction is large.

[0011]

EXAMPLE A first example will be described with reference to FIGS. FIG. 1 is a structural diagram showing the entire rotary electric machine. The air gap armature winding 3 arranged in the air gap between the rotor 1 and the stator core 2 has an inner peripheral surface of the stator core 2 via an armature winding support member 4 as shown in FIG. Fixing groove 5 provided on the
Fixed to. In the air gap armature winding 3, a cooling pipe is provided in the coil 6 that constitutes the winding, and the refrigerant is fed into the pipe through the air gap armature winding refrigerant supply / discharge pipe 7 for direct cooling.
The stator core 2 has a shape similar to that of the cooling member 8 of FIG. 2, and thin iron plates having a plurality of fixing grooves 5 along the inner peripheral surface thereof are axially laminated to form a stator core block 9. Then, a plurality of them are further laminated. In the middle of the stator block 9 there is a cooling member 8 which has a good thermal conductivity and therefore is usually conductive.
Has been inserted. Refrigerant is supplied to the cooling member 8 through a cooling member refrigerant supply / discharge pipe 10.

FIG. 2 is a partial view of a cross section of the stator at a position where the surface of the cooling member 8 can be seen. As shown in this figure, the cooling member 8 is usually divided into a fan shape and manufactured in the circumferential direction.
Arranged in a ring. In this embodiment, the ring is shown divided into six parts. A cooling medium supply / discharge port 11 connected to the cooling member coolant supply / discharge pipe 10 (see FIG. 1) is provided for each fan-shaped block, and the coolant is supplied to the cooling medium flow passage 12 provided inside the cooling member 8. The fixed groove 5 provided on the inner peripheral surface of the cooling member 8 is composed of a fixed groove bottom portion 13 and a fixed groove top portion 14. In the present embodiment, both the fixed groove bottom portion 13 and the fixed groove top portion 14 are provided with axial fine grooves according to the present invention, that is, one bottom fine groove 15 and one top fine groove 16. . FIG. 3 is a partial perspective view showing its appearance.

The magnetic flux generated by the field winding (not shown) provided in the container of the cylindrical rotor 1 enters the cooling member 8 and interlinks with it, and the cooling member 8 shown in FIG. Induced currents are intensively generated on the inner peripheral surface 17 of the bottom of the fixed groove and the inner peripheral surface 18 of the top of the fixed groove. However, the bottom groove 15 and the top groove 16 block the inner peripheral surface current in that portion, thereby limiting the magnitude of the respective inner peripheral surface induced currents. As a result, the occurrence of loss in this portion is significantly reduced, the local overheating generated on the inner peripheral surface of the cooling member 8 is significantly mitigated, and the loss of the entire cooling member 8 is also greatly reduced. FIG. 4 shows data showing the circumferential distribution of the magnetic flux in the vicinity of the cooling member fixing groove. Detailed electromagnetic field analysis was performed using an actual shape model manufactured to fit inside the superconducting generator equipped with air gap armature windings. It was obtained. Generally, the magnetic flux generated by the field winding of the rotor has a substantially sinusoidal distribution along the circumferential direction on the inner peripheral surface of the cylindrical stator core, but as shown in FIG. When the fixed groove 5 for supporting and fixing the armature winding support member 4 (see FIG. 1) is provided on the inner peripheral surface of the stator core block 9 formed by stacking, the magnetic flux density shown in FIG. Distribution. That is, the magnetic flux density is high in the vicinity of the top 14 of the fixed groove of the cooling member 8 and considerably lower in the vicinity of the bottom 13 than that. Therefore, the density of the magnetic flux incident on the cooling member 8 between the stator core blocks 9 changes along the circumferential direction,
The magnitude of the induced current generated in the cooling member 8 changes along the circumferential direction. In an actual operating state, the magnetic flux density distribution of FIG. 4 moves along the circumferential direction as the rotor 1 rotates, and the circumferential distribution of the loss generated in the cooling member 8 becomes uniform when the time average is taken. To be done. Further, although the magnetic flux that enters the cooling member 8 mainly enters in the radial direction, it is affected by the stator core block 9 that is made of a magnetic material, so that the magnetic flux that normally enters the cooling member 8 that is made of a non-magnetic material is included. The axial density distribution is not uniform. The above is the stator core 1
It means that the magnetic flux entering the cooling member 8 includes a radial component, a circumferential component, and an axial component due to the influence of the fixed groove 5 provided in the. The bottom narrow groove 15 and the top narrow groove 16 provided in the cooling member 8 work effectively for any magnetic flux component.

The width, depth, and number of these narrow grooves are the axial thickness of the cooling member 8, the number of circumferential divisions, the size of the fixed groove 5,
It is determined by performing detailed electromagnetic field analysis in consideration of dimensions such as axial thickness of the stator core block 9 and operating conditions. By providing the narrow groove according to the present invention thus determined on the inner peripheral surface of the cooling member 8, the current flowing through that portion is blocked, thereby limiting the induced current concentrated on the inner peripheral portion of the cooling member 8. The loss generated there can be reduced. The loss generated in the cooling member 8 and the iron loss generated in the stator core 1 are removed by the refrigerant flowing in the cooling member 8. As a result, local overheating is eliminated and a highly reliable stator for a rotating electric machine can be obtained.

A second embodiment will be described with reference to FIGS. The difference from the first embodiment is revealed by mounting the fixing groove member 19 made of a non-magnetic insulator on the inner circumference of the cooling member 8 having good heat conductivity, and therefore normally being conductive. The cooling structure of the cooling member 8 is similar to that of the first embodiment. The shape of the fixing groove 5 is the same as that of the first embodiment because it is aligned with the fixing groove 5 of the stator core 1, but the inner peripheral surface 20 of the cooling member 8 is formed in a smooth arc shape and fixed there. The outer peripheral surface of the groove member 19 is firmly adhered and fixed. Therefore, the inner peripheral narrow groove 21 in this embodiment is provided at the inner peripheral surface 20 of the cooling member 8. FIG. 5 shows an embodiment in which the inner peripheral narrow groove 21 is provided at a position facing the fixed groove bottom 13, and FIG. 6 is an embodiment in which the inner peripheral narrow groove 21 is provided at a position facing the fixed groove top 14. It is shown in the example.

In the case of this embodiment, the magnetic flux incident on the fixed groove member 19 and the cooling member 8 has a radial component due to the influence of the fixed groove 5 provided in the stator core 1 as in the case of the first embodiment. Although it includes a circumferential component and an axial component, the magnetic flux density becomes smaller as the inner circumferential surface 20 of the cooling member is further away from the fixed groove top 14. However, the effect of limiting the induced current provided with the inner peripheral narrow groove 21 is sufficiently large. If the inner circumferential narrow groove 21 is placed at the position facing the fixed groove top 14 shown in FIG. 6 rather than the position facing the fixed groove bottom 13 shown in FIG. The restriction effect of is increased. The width, depth and number of the fine grooves are determined by electromagnetic field analysis as in the case of the first embodiment. The cooling structure is similar to that of the first embodiment, but the cooling medium flow path 1
Although the cooling efficiency is improved for the cooling member 8 due to the narrow distance between the cooling member 2 and the inner peripheral surface 20 of the cooling member, the fixed groove member 19 is an insulator and not a good heat conductor for the stator core block 9. Only the cooling efficiency decreases. However, the cooling member inner peripheral surface 2
At 0, the effect of reducing the magnetic flux density and the effect of limiting the induced current by proper selection of the inner peripheral narrow groove 21 are great, and the loss generated in the inner peripheral portion of the cooling member 8 can be significantly reduced, and it also occurs locally. Since the effect of improving the cooling efficiency of the inner peripheral portion of the cooling member 8 which is easy to do is great, local overheating is eliminated and a highly reliable stator of the rotating electric machine can be obtained.

As a result of the electromagnetic field analysis, when the magnetic flux density is very high and it is necessary to increase the number of the inner peripheral narrow grooves 21 of the cooling member 8, the combination of the embodiments of FIGS. 5 and 6 is fixed, that is, fixed. An inner peripheral narrow groove 21 is provided at each of the opposing positions of both the groove bottom portion 13 and the fixed groove top portion 14. When the number of fine grooves is further increased, the number of the fine grooves is two at each of the facing positions of the bottom apex portions 13 and 14 of the fixed groove. Also in this case, it is usual that the inner peripheral narrow grooves 21 are equally spaced.

[0018]

EFFECTS OF THE INVENTION By providing a thin groove in the axial direction on the inner peripheral surface of a heat conductive and conductive cooling member inserted in the middle of a stator core block of a rotating electric machine, the cooling member is concentrated on the inner peripheral portion of the cooling member. It is possible to limit the induced current generated as a result. By selecting an appropriate shape and number of narrow grooves by electromagnetic field analysis, it became possible to suppress the loss in the inner circumference of the cooling member, eliminate local overheating, and greatly reduce the loss in the cooling member. It was possible to obtain a highly reliable stator for a rotating electric machine by eliminating local overheating.

[Brief description of drawings]

FIG. 1 is a structural cross-sectional view showing an entire rotary electric machine using the present invention.

FIG. 2 is a partial cross-sectional view of the stator on the surface of the cooling member showing the first embodiment.

FIG. 3 is a partial perspective view of a stator showing the first embodiment.

FIG. 4 is a distribution characteristic diagram of magnetic flux densities in the vicinity of a cooling member fixing groove of the air gap armature winding method.

FIG. 5 is a partial cross-sectional view of the stator on the surface of the cooling member showing the second embodiment. The arrangement | positioning of the fine groove in the fixed groove bottom part opposing position is shown.

FIG. 6 is a partial cross-sectional view of a stator on the surface of a cooling member showing a second embodiment. The arrangement | positioning of the fine groove in the fixed groove top part opposing position is shown.

[Explanation of symbols]

 2 Stator Core 5 Fixing Groove 8 Cooling Member 9 Stator Core Block 13 Fixing Groove Bottom 14 Fixing Groove Top 15 Bottom Fine Groove 16 Top Fine Groove 17 Fixing Groove Bottom Inner Surface 18 Fixing Groove Top Inner Surface 19 Fixing Groove Member 20 Inner peripheral surface of cooling member 21 Inner peripheral narrow groove

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takashi Haruta 3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Hitachi Factory (72) Inventor Tsutomu Kasei 3-chome, Hitachi City, Hitachi, Ibaraki Prefecture No. 1 Stock Company, Hitachi, Ltd., within the Hitachi Plant (56) References: Open 51-125506 (JP, U) Open 48-52003 (JP, U) Open 62-74486 (JP, U) Open Kaihei 2-113340 (JP, U)

Claims (4)

[Claims] 1. A cylindrical superconducting rotor has a hollow space around the outer circumference of the cylinder.
It is a cylindrical stator that is installed concentrically with a gap.
The stator is a cylindrical stator core and this stator core.
And a cylindrical stator winding supported on the inner peripheral surface side of the stator winding, the stator winding including a coil, a cooling pipe, and surrounding them.
And having a cylindrical support member for supporting, the stator core, a plurality of thin iron plates laminated in the axial direction,
Cooling member inserted and arranged at an appropriate position of this laminated body
And a flow path for a cooling medium provided inside the cooling member,
Has a laminate of thin steel plate and the cooling member of the stator iron core, of which
A plurality of fixing grooves are formed on the peripheral surface along the axial direction, and the supporting member of the stator winding has the stator on the outer peripheral surface thereof.
A protrusion that fits in the fixing groove of the laminated body of the thin iron plate and the cooling member of the iron core.
It has a ridge, and this ridge is fitted into the fixing groove to fix it.
The child winding is supported by the stator core, and the cooling member of the stator core corresponds to the shape of the thin iron plate.
It is a material with a good shape and good thermal conductivity and conductivity.
It is formed and has a small groove along the axial direction on the inner peripheral surface.
Is a superconducting rotating electric machine stator. 2. The fixing of the superconducting rotating electric machine according to claim 1.
In the child, the thin groove of the cooling member of the stator core is a bottom portion of the fixing groove.
And at least one of the tops
Characteristic Superconducting rotating electric machine stator. 3. A cylindrical superconducting rotor has a hollow space around the outer circumference of the cylinder.
It is a cylindrical stator that is installed concentrically with a gap.
The stator is a cylindrical stator core and this stator core.
And a cylindrical stator winding supported on the inner peripheral surface side of the stator winding, the stator winding including a coil, a cooling pipe, and surrounding them.
And having a cylindrical support member for supporting, the stator core, a plurality of thin iron plates laminated in the axial direction,
Cooling member inserted and arranged at an appropriate position of this laminated body
And a flow path for a cooling medium provided inside the cooling member,
Has a laminate of thin steel plate and the cooling member of the stator iron core, of which
A plurality of fixing grooves are formed on the peripheral surface along the axial direction, and the supporting member of the stator winding has the stator on the outer peripheral surface thereof.
A protrusion that fits in the fixing groove of the laminated body of the thin iron plate and the cooling member of the iron core.
It has a ridge, and this ridge is fitted into the fixing groove to fix it.
The child winding is supported by the stator core, and the cooling member of the stator core corresponds to the shape of the thin iron plate.
The portion having the fixed shape and having the fixing groove is made of an insulator.
Other parts are made of materials that have good thermal conductivity and conductivity.
Is formed integrally with the inner surface of the other part in the axial direction
A stator of a superconducting rotating electric machine having a narrow groove along it . 4. The fixing of the superconducting rotating electric machine according to claim 3.
In the child, the thin groove of the cooling member of the stator core is a bottom portion of the fixing groove.
And at least one of the tops
A stator for a superconducting rotating electric machine, characterized in that