Rotating machine stator

Abstract

To make it possible to achieve both a large current capacity and low AC loss.SOLUTION: A rotating machine stator (10) includes a plurality of winding frames (20) and a coil portion (40) constituted by a thin film superconducting wire (51) arranged on the winding frame. The winding frame includes a frame body (21) extending in the circumferential direction, a plurality of inner slots (23) formed at predetermined intervals in the circumferential direction on the inner peripheral side of the frame body, and a plurality of outer slots (24) formed at predetermined intervals in the circumferential direction on the outer peripheral side of the frame body and adjacent to the inner slots in the circumferential direction. The coil portion is wound with a laminated conductor (50) in which a plurality of the thin film superconducting wires are laminated, inserted inside the inner slots and the outer slots, with the laminated conductor facing the circumferential direction. The laminated conductor in the circumferentially adjacent inner slot and the laminated conductor in the outer slot are arranged such that the circumferential orientation is reversed when viewed from the axial direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stator for a rotating machine, and more particularly to a stator for a rotating machine using superconductivity. [Background technology]

[0002] Patent Document 1 discloses a superconducting motor in which superconducting coils corresponding to each phase are arranged along the inner circumference of a stator. The superconducting coils are formed by winding a tape-shaped superconducting wire in a spiral shape. A much larger current can be passed through a superconducting coil compared to a coil made of normal copper wire, etc., and a large magnetic flux density can be generated even when the number of turns of the coil is small. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-176582 A Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration of Patent Document 1 has a problem in that when a magnetic field is applied to the superconducting wire used in the coil, a shielding current that shields the magnetic field is induced, and the shielding current increases AC loss.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a stator for a rotating machine that can achieve both a large current capacity and low AC loss. [Means for solving the problem]

[0006] A stator of a rotating machine according to one aspect of the present invention is a stator of a rotating machine including a plurality of winding frames arranged at equal intervals in the circumferential direction, and a coil portion constituted by a thin film superconducting wire arranged on the winding frame, the thin film superconducting wire includes a band-shaped base extending in the longitudinal direction, and a plurality of superconducting layers formed by filamentizing superconducting sections laminated on the base, the winding frame includes a frame body extending in the circumferential direction, a plurality of inner slots formed at predetermined intervals in the circumferential direction on the inner peripheral side of the frame body, and a plurality of inner slots formed at predetermined intervals in the circumferential direction on the outer peripheral side of the frame body. the coil portion is wound with a laminated conductor formed by stacking a plurality of the thin-film superconducting wires inside the inner slot and the outer slot, with the laminated conductor being wound with the lamination direction in the area inserted into the inner slot and the outer slot facing the circumferential direction, and the laminated conductor in the circumferentially adjacent inner slots and the laminated conductor in the outer slot are arranged with their circumferential orientations reversed when viewed from the axial direction. Effect of the Invention

[0007] According to the present invention, the coil portion is made of a laminated conductor in which multiple thin-film superconducting wires are laminated, so that the current capacity per unit volume can be increased compared to coils used in normal motors. Furthermore, the laminated conductors in the inner slots and the laminated conductors in the outer slots are arranged in a reversed state in the circumferential direction. As a result, the interlinkage magnetic flux generated in the laminated conductors in the inner slots and the interlinkage magnetic flux generated in the laminated conductors in the outer slots are in opposite directions and cancel each other out, reducing the generation of shielding current and reducing AC loss per unit volume. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view perpendicular to an axial direction of a stator of a rotating machine according to an embodiment. [Diagram 2] 2 is a partially enlarged view of FIG. 1 showing a bobbin and a coil portion. [Diagram 3] FIG. [Figure 4]4A is an exploded cross-sectional view of a laminated conductor, FIG. 4B is a cross-sectional view of a laminate, FIG. 4C is a schematic diagram of the laminate of FIG. 4B, and FIG. 4D is a perspective view showing a schematic diagram of a thin-film superconducting wire. [Diagram 5] 10 is an explanatory diagram illustrating a case where an external magnetic field is applied to a laminated conductor in a radial direction. FIG. [Figure 6] 10 is an explanatory diagram illustrating a case where an external magnetic field is applied to a laminated conductor in a circumferential direction. [Figure 7] 11 is an explanatory diagram of the phase and polarity of a magnetic field after each coil section is combined. FIG. [Figure 8] FIG. 6 is an explanatory diagram similar to FIG. 5 according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a rotating machine stator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiment, and can be appropriately modified without departing from the spirit and scope of the present invention. In the following drawings, some components may be omitted for the sake of convenience.

[0010] In this specification and claims, unless otherwise specified, the terms "inside", "inner circumference side", "outside", "outer circumference side", "circumferential direction", "axial direction", and "radial direction" refer to the "inside", "inner circumference side", "outside", "outer circumference side", "circumferential direction", "axial direction", and "radial direction" of the stator of a rotating machine.

[0011] Fig. 1 is a cross-sectional view perpendicular to the axial direction of a stator of a rotating machine according to an embodiment. As shown in Fig. 1, the stator 10 includes six winding frames 20 arranged at equal intervals in the circumferential direction, and a coil section 40 disposed on each of the six winding frames 20. Thus, the stator 10 includes six coil sections 40. In the stator 10, one winding frame 20 and one coil section 40 form an armature coil.

[0012] The stator 10 is provided in a cylindrical shape and constitutes a rotating machine (not shown) as a stator. In the rotating machine, a rotor (not shown) whose center of rotation is parallel to the axial direction is rotatably provided inside the stator 10.

[0013] The six winding frames 20 have the same configuration and are provided at 60° intervals in the circumferential direction so that the number of poles is two as described below. Fig. 2 is a partially enlarged view of Fig. 1 showing the winding frames and coil section. The winding frame 20 includes a frame body 21 extending in the circumferential direction, a plurality of inner slots 23 formed at predetermined intervals in the circumferential direction on the inner peripheral side of the frame body 21, and a plurality of outer slots 24 formed at predetermined intervals in the circumferential direction on the outer peripheral side of the frame body 21.

[0014] The frame main body 21 has a step forming portion 26 formed in the circumferential center, a first forming portion 27 formed on one circumferential side (left side in Figure 2) from the step forming portion 26, and a second forming portion 28 formed on the other circumferential side (right side in Figure 2) from the step forming portion 26.

[0015] When viewed from the axial direction, the frame body 21 is formed in a shape bent like a crank around the step forming portion 26, and the second forming portion 28 is formed radially inward from the first forming portion 27. Each forming portion 27, 28 is curved in an arc shape in the circumferential direction and is formed within an angle range of about 30°. In the radial direction, the first forming portion 27 located inward is formed to have a smaller diameter dimension than the second forming portion 28 located outward.

[0016] The inner slots 23 are formed so as to open the inner circumferential surface of each of the forming portions 27, 28, and the coil portion 40 is inserted through the opening. In this embodiment, the number of the inner slots 23 formed in each of the forming portions 27, 28 is 12, and they are formed at equal intervals in the circumferential direction. Note that the number of the inner slots is not particularly limited, and may be increased or decreased as long as it is more than one.

[0017] The outer slots 24 are formed so as to open the outer circumferential surface of each of the forming portions 27, 28, and the coil portion 40 is inserted through the opening. In this embodiment, the number of the outer slots 24 formed in each of the forming portions 27, 28 is 12, and the outer slots 24 are formed at equal intervals in the circumferential direction so as to be adjacent to the step forming portion 26 side of the inner slot 23 in the circumferential direction.

[0018] Fig. 3 is a perspective view of the winding frame and the coil portion. As shown in Fig. 3, the coil portion 40 is formed by spirally winding one laminated conductor 50 around one winding frame 20. Here, the configuration of the laminated conductor 50 will be described with reference to Fig. 4.

[0019] Fig. 4A is an exploded cross-sectional view of the laminated conductor, and Fig. 4B is a cross-sectional view of the laminate. As shown in Fig. 4A and Fig. 4B, the laminated conductor 50 is made into a conductor by stacking six (plural) thin-film superconducting wires 51 in the thickness direction. Thus, the coil section 40 formed by winding the laminated conductor 50 is composed of a plurality of stacked thin-film superconducting wires 51. The stacked thin-film superconducting wires 51 are insulated from each other.

[0020] Fig. 4D is a perspective view showing a thin-film superconducting wire. As shown in Fig. 4D in addition to Fig. 4A and Fig. 4B, thin-film superconducting wire 51 is formed by laminating insulating layer 54 and superconducting layer 55 on one surface in the thickness direction of band-shaped base 53 extending in the longitudinal direction. While base 53 has a thickness of about 0.1 mm, insulating layer 54 and superconducting layer 55 have a thickness of several tens of µm or less, which is extremely thin. A metal layer (not shown) is appropriately laminated on the surface of superconducting layer 55 opposite insulating layer 54. Base 53 has a width of about 2 mm to 10 mm, so thin-film superconducting wire 51 can be easily bent in the thickness direction but not easily in the width direction.

[0021] The thin-film superconducting wire 51 is formed by laminating an insulating layer 54 and a superconducting layer 55 as a superconducting portion over the entire surface of one thickness direction of a base 53, and then forming three grooves 57 along the longitudinal direction of the superconducting portion, thereby forming four (multiple) superconducting layers 55 into a filament.

[0022] A preferred example of the thin-film superconducting wire 51 is a bismuth-based or rare earth-based superconducting wire. A preferred example of the bismuth-based superconducting wire is a Bi-2223 wire having a Bi-2223 phase as the main phase, with a composition ratio (molar ratio) of (Bi+Pb):Sr:Ca:Cu of about 2:2:2:3. The Bi-2223 wire has a high critical temperature of about 110K, and a critical current value is 100 times that of a copper wire at 77K and 200 to 300 times that of a copper wire when not in a coiled form, and even when in a coiled form, a very large critical current value of about half the value can be obtained.

[0023] Rare earth-based superconducting wire is a high-temperature superconducting wire (REBCO wire) composed of Re (rare earth)-Ba-Cu-O, with holmium being an example of the rare earth. Rare earth-based superconducting wire can achieve a higher current density than bismuth-based superconducting wire, and also has the characteristic of good magnetic field resistance.

[0024] Fig. 4C is a simplified diagram of the laminated conductor in Fig. 4B. When showing a cross section perpendicular to the longitudinal direction of laminated conductor 50, the laminated state as shown in Fig. 4B may be shown in a simplified form as shown in Fig. 4C (see Fig. 2). In laminated conductor 50 in Fig. 4C, the up-down direction in the figure is the lamination direction of thin-film superconducting wires 51, and to show the orientation of the lamination direction, a dotted rectangular base position 50a in the figure is shown on the side where base 53 of laminated thin-film superconducting wires 51 is located.

[0025] As shown in FIG. 2, the coil portion 40 includes an inner winding portion 40a formed by inserting a laminated conductor 50 into each inner slot 23 on the inner side of the winding frame 20, and an outer winding portion 40b formed by inserting a laminated conductor 50 into each outer slot 24 on the outer side of the winding frame 20.

[0026] 3, the inner winding portion 40a of the coil portion 40 is formed into a racetrack-like outer shape and into a pancake shape with the laminated conductor 50 wound spirally. In the inner winding portion 40a, the range where the laminated conductor 50 is inserted into each inner slot 23 of the winding form 20 is formed into a straight line parallel to the axial direction, and the portions protruding from both sides of the winding form 20 in the axial direction are curved into a roughly semicircular arc shape.

[0027] The outer winding portion 40b is disposed on the rear side of the inner winding portion 40a in FIG. 3, and is formed in the same manner as the inner winding portion 40a. In the outer winding portion 40b, the range where the laminated conductor 50 is inserted into each outer slot 24 (not shown in FIG. 3, see FIG. 2) of the reel 20 is formed in a straight line parallel to the axial direction, and the portion protruding from both sides of the reel 20 in the axial direction is formed to be curved in a substantially semicircular arc. The coil portion 40 including the inner winding portion 40a and the outer winding portion 40b has a distributed winding structure. Note that "formed in a straight line parallel to the axial direction" in the inner winding portion 40a and the outer winding portion 40b includes a case where the inner winding portion 40a and the outer winding portion 40b are slightly tilted or curved with respect to the axial direction due to skew, processing accuracy, tolerance, likelihood, etc.

[0028] Returning to FIG. 2, an example of a method for winding the laminated conductor 50 in the coil section 40 will be described below. Here, first, the laminated conductor 50 is wound to form the inner winding section 40a of the coil section 40. The first winding of the laminated conductor 50 is started by inserting the laminated conductor 50 into the first (leftmost in FIG. 2) inner slot 23 from the tip (left end in FIG. 2) of the first forming section 27 toward the step forming section 26. The laminated conductor 50 inserted into the inner slot 23 has the lamination direction facing the circumferential direction, and the base position 50a of the laminated conductor 50 is arranged on the step forming section 26 side in the circumferential direction. Therefore, in the laminated conductor 50 in the range inserted into the inner slot 23 of the first forming section 27, the base 53 of each thin film superconducting wire 51 is arranged on the step forming section 26 side in the circumferential direction.

[0029] As described above, the laminated conductor 50 inserted into the inner slot 23 of the first forming portion 27 is curved at a position protruding from both axial ends of the frame body 21, so as to face the second forming portion 28 (see FIG. 3). Then, the laminated conductor 50 is inserted into the first (rightmost in FIG. 2) inner slot 23 from the tip (right end in FIG. 2) of the second forming portion 28 toward the step forming portion 26. Even in the range of the laminated conductor 50 inserted inside the inner slot 23, the lamination direction is oriented in the circumferential direction, and the base position 50a of the laminated conductor 50 is disposed on the step forming portion 26 side in the circumferential direction.

[0030] The laminated conductor 50 thus inserted into the inner slot 23 of the second forming portion 28 is curved at a position protruding from both axial ends of the frame body 21, so as to face the first forming portion 27 (see FIG. 3). This completes the first turn of the spirally wound laminated conductor 50, and the second and subsequent turns of the spirally wound laminated conductor 50 are then repeatedly wound.

[0031] In the second and subsequent windings, the inner slot 23 into which the laminated conductor 50 is inserted is changed to the inner slot 23 adjacent to the step forming portion 26 side, compared to the previous winding, and the rest is performed in the same manner as above. In this embodiment, the number of inner slots 23 formed in each of the first forming portion 27 and the second forming portion 28 is set to 12, so that the 12th winding of one turn is the final winding in the formation of the inner winding portion 40a. With this final winding, the laminated conductor 50 is inserted into the inner slot 23 closest to the step forming portion 26 in the second forming portion 28 (the leftmost one in FIG. 2), and the base position 50a of the laminated conductor 50 is also positioned on the step forming portion 26 side in the circumferential direction. Therefore, in the formation of the inner winding portion 40a, the bases 53 of the thin film superconducting wires 51 of the laminated conductor 50 inserted into all the inner slots 23 are positioned on the step forming portion 26 side in the circumferential direction.

[0032] After the winding to form the inner winding portion 40a, the laminated conductor 50 is continuously wound from the inside to the outside of the frame body 21 to form the outer winding portion 40b. In forming the outer winding portion 40b, the first winding of the laminated conductor 50 is started by inserting the laminated conductor 50 into the first (leftmost in FIG. 2) outer slot 24 from the tip (left end in FIG. 2) of the first forming portion 27 toward the step forming portion 26. The laminated conductor 50 inserted into the outer slot 24 has the lamination direction facing the circumferential direction, and the base position 50a of the laminated conductor 50 is disposed on the opposite side to the step forming portion 26 in the circumferential direction. Therefore, in the laminated conductor 50 inserted into the outer slot 24 of the first forming portion 27, the base 53 of each thin film superconducting wire 51 is disposed on the opposite side to the step forming portion 26 in the circumferential direction.

[0033] In order to achieve this arrangement, after the winding to form the inner winding portion 40a is completed, the laminated conductor 50 is inverted (rotated 180°) around the extending direction before the winding to form the outer winding portion 40b is started (see the arrow indicated by the dashed line in FIG. 2). More specifically, the laminated conductor 50 is inverted as described above in a range R (see FIG. 3) between a portion of the laminated conductor 50 inserted into the inner slot 23 closest to the step forming portion 26 in the second forming portion 28 and a portion of the end of the first forming portion 27 inserted into the outer slot 24 on the leftmost side in FIG. 2. As a result, the inner slot 23 and the outer slot 24 are adjacent to each other in the circumferential direction at the leftmost side in FIG. 2 of the first forming portion 27, but the laminated conductor 50 in the inner slot 23 and the laminated conductor 50 in the outer slot 24 are arranged in such a way that their circumferential orientations are inverted when viewed from the axial direction. In other words, this arrangement is adjusted in the range R of the laminated conductor 50 connecting the inner winding portion 40a and the outer winding portion 40b.

[0034] The subsequent winding to form the outer winding portion 40b is performed in a similar manner to the winding to form the inner winding portion 40a. To be more specific, the laminated conductor 50 inserted into the outer slot 24 of the first forming portion 27 as described above is bent at a position protruding from both axial ends of the frame body 21, so as to be directed toward the second forming portion 28. Then, the laminated conductor 50 is inserted into the first (rightmost in FIG. 2) outer slot 24 from the tip (right end in FIG. 2) of the second forming portion 28 toward the step forming portion 26. The laminated conductor 50 inserted into the outer slot 24 has a lamination direction oriented in the circumferential direction, and the base position 50a of the laminated conductor 50 is disposed on the opposite side of the step forming portion 26 in the circumferential direction.

[0035] As described above, the laminated conductor 50 inserted into the outer slot 24 of the second forming portion 28 is curved at a position protruding from both axial ends of the frame body 21, so as to face the first forming portion 27. This completes the first winding of the spirally wound laminated conductor 50, and subsequently, the second and subsequent windings are repeated.

[0036] In the second and subsequent windings, the outer slot 24 into which the laminated conductor 50 is inserted is changed to the adjacent outer slot 24 on the step forming portion 26 side, compared to the previous winding, and the rest is performed in the same manner as above. In this embodiment, the number of outer slots 24 formed in each of the first forming portion 27 and the second forming portion 28 is 12, so that the 12th winding of one turn is the final winding in the formation of the outer winding portion 40b. With this final winding, the laminated conductor 50 is inserted into the outer slot 24 closest to the step forming portion 26 in the second forming portion 28 (the leftmost one in FIG. 2), and the base position 50a of the laminated conductor 50 is also located on the opposite side to the step forming portion 26 in the circumferential direction.

[0037] Therefore, by forming the outer winding portion 40b, the base portion 53 of each thin film superconducting wire 51 of the laminated conductor 50 inserted into all of the outer slots 24 is arranged on the opposite side in the circumferential direction to the step forming portion 26. As a result, in all of the inner slots 23 and outer slots 24 adjacent in the circumferential direction, the laminated conductor 50 in the inner slot 23 and the laminated conductor 50 in the outer slot 24 are arranged in such a way that their circumferential orientations are reversed when viewed from the axial direction. Next, the operation and effect of the configuration with such an arrangement will be described below with reference to Figs. 5 and 6.

[0038] Fig. 5 is an explanatory diagram of a case where an external magnetic field is applied to the laminated conductor in the radial direction. Fig. 6 is an explanatory diagram of a case where an external magnetic field is applied to the laminated conductor in the circumferential direction. In the coil section 40, the direction of the applied magnetic field changes depending on the direction of the rotating rotor (not shown). Here, a case where an external magnetic field parallel to the radial direction indicated by arrow B1 in Fig. 5 is applied to the laminated conductor 50 of the coil section 40, and a case where an external magnetic field parallel to the circumferential direction indicated by arrow B2 in Fig. 6 are applied will be described.

[0039] 5, when an external magnetic field parallel to the radial direction indicated by arrow B1 is applied to the laminated conductor 50, the flux linkage between the wires (thin film superconducting wires 51, strands) generated in the laminated conductor 50 in the inner slot 23 and the flux linkage between the wires generated in the laminated conductor 50 in the outer slot 24 cancel each other out in the vertical direction in the figure. This is because the inner slots 23 and outer slots 24 adjacent to each other in the circumferential direction are arranged in an inverted manner, and therefore the flux linkage generated in each slot is in the opposite direction.

[0040] 6, when an external magnetic field parallel to the circumferential direction indicated by arrow B2 is applied to the laminated conductor 50, the flux linkage between the filaments (superconducting layers 55) in the wire generated in the laminated conductor 50 in the inner slot 23 and the flux linkage between the filaments in the wire generated in the laminated conductor 50 in the outer slot 24 cancel each other out in the left-right direction in the figure. This is also because the inner slots 23 and outer slots 24 adjacent to each other in the circumferential direction are arranged in an inverted circumferential direction, and therefore the flux linkage generated in each slot is in the opposite direction.

[0041] 5 and 6, regardless of whether the magnetic field applied to the laminated conductor 50 is in the radial or circumferential direction, the laminated conductor 50 in the inner slot 23 and the laminated conductor 50 in the outer slot 24 are arranged in a state in which the circumferential direction is reversed, and thus the interlinkage magnetic flux is cancelled out as described above. This makes it possible to reduce the generation of shielding current in each laminated conductor 50 and reduce AC loss per unit volume.

[0042] Returning to FIG. 1, in each coil portion 40 formed by winding the laminated conductor 50 around the bobbin 20 as described above, the polarity is opposite between the first forming portion 27 and the second forming portion 28. Furthermore, since the stator 10 of this embodiment constitutes a three-phase AC rotating machine, each coil portion 40 is configured to correspond to the U phase, V phase, and W phase. In the following description, the coil portion 40 forming the range from approximately 3 o'clock to approximately 7 o'clock in FIG. 1 (the coil portion 40 enlarged in FIG. 2) is referred to as the first coil portion 41. Furthermore, the other coil portions 40 are referred to as second to sixth coil portions 46 in order in the circumferential clockwise direction from the first coil portion 41.

[0043] The phases (U-phase, V-phase, W-phase) and polarities of the first forming portion 27 and the second forming portion 28 in the first to sixth coil portions 41 to 46 are set as shown in Fig. 1 and Table 1. The polarities are written in parentheses after the phase.

[0044] [Table 1]

[0045] To explain some of the phases and polarities of the first to sixth coil portions 41 to 46 by way of example, in the range where the first coil portion 41 is wound around the first forming portion 27 of the winding frame 20, the phase is U-phase and the polarity is negative (-). The first forming portion 27 around which the first coil portion 41 is wound is positioned so as to overlap radially outwardly with the second forming portion 28 of the adjacent winding frame 20 in the clockwise circumferential direction (one side). The second coil portion 42 is wound around this adjacent winding frame 20. In the range where the second coil portion 42 is wound around the second forming portion 28 of the winding frame 20, the phase is V-phase and the polarity is negative (-).

[0046] The first forming portion 27 and the second forming portion 28 of the winding frame 20 adjacent in the circumferential direction overlap in the radial direction, and the first coil portion 41 and the second coil portion 42, which are two different phases, also overlap in the radial direction. When a three-phase AC current flows through the first coil portion 41 and the second coil portion 42, a composite magnetic field is generated in the range where the first coil portion 41 and the second coil portion 42 overlap in the radial direction. Here, the currents of each phase of the three-phase AC circuit are added together to become "zero." As a result, a magnetic field corresponding to a current of phase W and polarity positive (+) is generated as a composite magnetic field by the current of phase U of the first coil portion 41 and polarity negative, and the current of phase V of the second coil portion 42 and polarity negative (+) (see Table 1).

[0047] Fig. 7 is an explanatory diagram of the phase and polarity of the magnetic field after the coil sections are combined. In the above, the magnetic field in the area where the first coil section 41 and the second coil section 42 overlap has been described, but as shown in Fig. 7 and Table 1, the other coil sections 41-46 also generate a similarly combined magnetic field. As a result, the first to sixth coil sections 41-46 can generate a rotating magnetic field required for a three-phase AC rotating machine with two poles.

[0048] As described above, according to the above embodiment, the coil portion 40 is formed by winding the thin film superconducting wire 51, so that the current capacity per unit volume can be increased. Moreover, as shown in Fig. 5 and Fig. 6, the interlinkage magnetic flux generated in each laminated conductor 50 in the inner slot 23 and the outer slot 24 cancels each other out, suppressing the generation of shielding current and reducing AC loss per unit volume. Therefore, the stator 10 of the above embodiment can simultaneously achieve both a large current capacity and low AC loss.

[0049] In addition, in order to achieve an arrangement state in which the interlinkage magnetic fluxes generated in each laminated conductor 50 in the inner slot 23 and the outer slot 24 cancel each other out, the laminated conductor 50 is configured to be inverted around the extension direction in the range R connecting the inner winding portion 40a and the outer winding portion 40b in the laminated conductor 50. This makes it possible to eliminate the need to change the orientation of the laminated conductor 50 or to connect two laminated conductors 50 for each laminated conductor 50 in adjacent inner slots 23 and outer slots 24. In other words, by performing a simple task of inverting the laminated conductor 50 once for one coil portion 40, the laminated conductor 50 can be arranged in the arrangement state shown in FIG. 2, and the workability of manufacturing each coil portion 40 can be improved.

[0050] In the above embodiment, the coil section 40 has the thin-film superconducting wire 51 in a distributed winding structure, but as a comparative structure to the above, a coil section in which the thin-film superconducting wire 51 has a racetrack-shaped concentrated winding structure similar to the above was studied. Such a study and comparison with the above embodiment are described below.

[0051] Since it is difficult to form a complicated winding shape in the thin-film superconducting wire 51, when adopting the concentrated winding structure of the comparative structure, it is considered to form a double pancake-shaped winding shape. When the stator is formed with this winding shape, the winding pitch becomes small and the distance between the windings of different phases becomes large. For example, in a two-pole machine in which one phase is formed with two windings, totaling six windings, the winding pitch becomes about 45° and the winding factor becomes small. As a result, in order to increase the magnetomotive force to realize the desired output, it is necessary to increase the number of turns, but an increase in the number of turns increases AC loss. In addition, in the concentrated winding structure, the rotating magnetic field generated essentially contains large harmonics, which becomes more noticeable when there is an air gap between different phases. This increases the ripple factor, and when the rotor contains a metal part, it also increases the eddy current loss of the rotor. Similarly, when the rotor is a superconducting winding, AC loss due to harmonic components increases.

[0052] In contrast, the coil section 40 in the above embodiment has a distributed winding structure. This allows the winding factor to be increased and the number of turns to be reduced compared to a concentrated winding structure. This reduction in the number of turns allows AC losses to be reduced. Furthermore, the distributed winding structure allows spatial harmonics to be reduced compared to a concentrated winding structure, and this reduction in spatial harmonics allows the ripple factor, rotor eddy current loss, and AC loss to be reduced.

[0053] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways. In the above-mentioned embodiment, the size, shape, orientation, etc. shown in the attached drawings are not limited to these, and can be modified as appropriate within the scope of the effects of the present invention. In addition, the present invention can be modified as appropriate without departing from the scope of the purpose of the present invention.

[0054] In the above embodiment, the number of winding frames 20 and coil portions 40 may be more than six, and may be less than six, for example, the circumferential range may be about half that of the above embodiment (about 30° in the circumferential direction) to 12. In this case, the number of poles may be four.

[0055] Furthermore, the number of inner slots 23 and outer slots 24 formed may be increased or decreased depending on the number of turns of the laminated conductor 50 in the coil portion 40 .

[0056] Furthermore, the number of thin film superconducting wires 51 stacked in laminated conductor 50 may be more or less than six if multiple, and the number of superconducting layers 55 formed on one thin film superconducting wire 51 may be more or less than four if multiple.

[0057] In addition, the method of winding the laminated conductor 50 in the coil portion 40 may be such that the order of winding the inner winding portion 40a and the outer winding portion 40b is reversed, and the outer winding portion 40b is wound first, and then the inner winding portion 40a is wound. Furthermore, in the above embodiment, in order to wind the laminated conductor 50 in a spiral shape, the winding proceeds from the outside of the spiral toward the center in the first forming portion 27 and the second forming portion 28, but this may be reversed and the winding proceeds from the center of the spiral toward the outside.

[0058] In addition, in the above embodiment, the laminated conductor 50 is configured to be rotated 180° around the extension direction in the range R of the laminated conductor 50 connecting the inner winding portion 40a and the outer winding portion 40b, but this may be changed as long as the laminated conductor 50 can be adjusted to the orientation and arrangement shown in Fig. 2. For example, the laminated conductor 50 may be rotated 540° around the extension direction, which is substantially the same as the orientation rotated 180°.

[0059] In the above embodiment, the laminated conductor 50 is inserted once into each of the inner slots 23 and the outer slots 24, but the present invention is not limited to this, and may be configured as shown in FIG. 8. FIG. 8 is an explanatory diagram similar to FIG. 5 according to a modified example. In the modified example of FIG. 8, a plurality of laminated conductors 50 (two in FIG. 8) are arranged side by side in the radial direction to be inserted into the inner slots 23 and the outer slots 24. In this arrangement, the coil section 40 is provided so that the laminated conductor 50 is arranged in multiple layers in the radial direction in each of the slots 23 and 24 while winding one laminated conductor 50. With this configuration, it is possible to increase the magnetomotive force (increase the synchronous machine output), and even if the laminated conductor 50 in multiple layers in each of the slots 23 and 24 is misaligned, it is possible to cancel the interlinkage magnetic flux as a whole by the same principle as described above. Note that the laminated conductors 50 arranged side by side in the radial direction are two layers in FIG. 8, but may be three or more layers. [Explanation of symbols]

[0060] 10: Stator 20: Winding frame 21: Frame body 23: Inner slot 24: Outer slot 26: Step forming section 27:First forming part 28:Second forming part 40: Coil section 40a: Inner winding part 40b: Outer winding part 50:Laminated conductor 51: Thin film superconducting wire 53: Base 55: Superconducting layer

Claims

1. A plurality of winding frames arranged at equal intervals in the circumferential direction; a coil portion formed of a thin film superconducting wire disposed on the bobbin, The thin film superconducting wire has a strip-shaped base portion extending in a longitudinal direction, a plurality of superconducting layers formed by filamenting the superconducting parts laminated on the base, The winding frame includes a frame body extending in a circumferential direction, A plurality of inner slots formed at predetermined intervals in a circumferential direction on an inner peripheral side of the frame body; a plurality of outer slots formed at predetermined intervals in a circumferential direction on an outer circumferential side of the frame body and adjacent to the inner slot in a circumferential direction; the coil portion is wound in a state in which a laminated conductor in which a plurality of the thin film superconducting wires are laminated is inserted into the inside of the inner slot and the outer slot, and the laminated conductor is laminated in a state in which a lamination direction of the laminated conductor in a range inserted into the inner slot and the outer slot is oriented in a circumferential direction; A stator for a rotating machine, characterized in that the laminated conductors in the inner slots and the laminated conductors in the outer slots that are adjacent to each other in the circumferential direction are arranged in such a way that their circumferential orientations are reversed when viewed from the axial direction.

2. The coil portion includes an inner winding portion in which the laminated conductor is inserted into a plurality of the inner slots and wound around the inner winding portion; 2. The stator of a rotating machine according to claim 1, further comprising an outer winding portion in which the laminated conductor is inserted into a plurality of the outer slots and wound around the outer winding portion, and the arrangement state is adjusted by the laminated conductor connecting the inner winding portion and the outer winding portion.

3. 3. The stator of a rotating machine according to claim 2, wherein the laminated conductor is rotated 180 degrees around the extending direction in a range connecting the inner winding portion and the outer winding portion.

4. The frame body has a step forming portion formed in a circumferential center portion, a first forming portion formed on one circumferential side of the step forming portion; a second forming portion formed on the other circumferential side from the step forming portion and radially inward from the first forming portion, A stator for a rotating machine as described in any one of claims 1 to 3, characterized in that, in each of the plurality of winding frames, the first forming portion overlaps the radially outer side of the second forming portion of an adjacent winding frame on one circumferential side, thereby causing different coil portions to overlap in the radial direction.

5. 4. The stator of a rotating machine according to claim 1, wherein the thin-film superconducting wire is made of a bismuth-based or rare earth-based superconducting wire.

6. 4. The stator of a rotating machine according to claim 1, wherein a plurality of the laminated conductors are inserted into the inside slots and the outside slots and are arranged side by side in the radial direction.

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