Winding structure of rotary electric machine

Abstract

To provide a winding structure capable of preventing or suppressing circulating current.SOLUTION: A winding structure 10 of a rotary electric machine 12 is formed by winding a winding around a plurality of slots 20 formed between a plurality of teeth of a stator 14. A winding 24 is formed by bundling a plurality of unit windings 25 in the radial direction of the stator 14. A plurality of coil portions 30 that constitutes the same phase is formed by winding the winding 24 on each of the plurality of slots. The arrangement order of the plurality of unit windings 25 in the radial direction is reversed between adjacent coil portions 30 of the same phase.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a winding structure for a rotating electrical machine. [Background technology]

[0002] In recent years, research and development into energy efficiency has been conducted in various fields, including the field of rotating electrical machines, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. When circulating currents occur in the stators of rotating electrical machines due to leakage flux (flux linkage), the efficiency of the machines decreases. For this reason, for example, the winding structure of Patent Document 1 attempts to suppress the generation of circulating currents by devising the cross-sectional shape of the windings (strands of wires). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-136300 Summary of the Invention [Problem to be solved by the invention]

[0004] In the winding structure of Patent Document 1, the circulating current increases depending on how the winding is wound. Therefore, it is desired to be able to more effectively prevent or suppress the circulating current.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] An aspect of the present disclosure is a winding structure for a rotating electric machine in which a unit winding is formed by bundling a plurality of wires, a winding is formed by bundling a plurality of the unit windings in the radial direction of the stator of the rotating electric machine, and the winding is wound into a plurality of slots formed between a plurality of teeth of the stator that are arranged opposite to a rotor, and a plurality of coil portions that constitute the same phase are formed by winding the windings into the plurality of slots, respectively, and the order of the unit windings in the radial direction is reversed between adjacent coil portions in the same phase. [Effects of the Invention]

[0007] According to the winding structure of the rotating electric machine of the present invention, the order of the unit windings is reversed between adjacent coil portions, so that potential differences between adjacent coil portions (between poles) in the same phase are canceled out, preventing or suppressing the generation of circulating currents, thereby contributing to energy efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a winding structure of a rotating electrical machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of the winding structure. [Figure 3] FIG. 3 is a circuit diagram of the winding structure. [Figure 4] FIG. 4 is a schematic diagram of a winding structure according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] In Fig. 1, a plurality of teeth 18 are provided on a stator 14 of a rotating electric machine 12, facing a rotor 16. A plurality of slots 20 are formed between the plurality of teeth 18. A winding structure 10 of the rotating electric machine 12 is formed by winding a winding 24 around the plurality of slots 20. The rotating electric machine 12 may be an electric motor or a generator. The rotating electric machine 12 may be a three-phase AC electric motor or a three-phase AC generator.

[0010] The rotating electric machine 12 includes a rotor 16 and a stator 14. The radial direction of the rotor 16 and the radial direction of the stator 14 are the same direction. For this reason, hereinafter, the radial direction of the rotor 16 and the radial direction of the stator 14 may be simply referred to as the "radial direction" without distinguishing between them. Note that the "radial direction" may also be used to describe each component of the stator 14.

[0011] The rotor 16 is rotatably supported by bearings (not shown). In Fig. 1, the rotor 16 is rotatable inside the stator 14. The rotor 16 is also rotatable outside the stator 14. The rotor 16 has a plurality of permanent magnets. The number of poles of the rotating electric machine 12 corresponds to the number of permanent magnets, and can be, for example, 2, 4, 6, 8, or 10 poles.

[0012] The stator 14 includes a stator core 22 and a winding 24. The stator core 22 is made of a magnetic material. The stator core 22 has an annular portion 19 and a plurality of teeth 18. The annular portion 19 forms the outer periphery of the stator core 22. The plurality of teeth 18 protrude radially inward (in the R2 direction) from the annular portion 19. That is, the plurality of teeth 18 protrude from the annular portion 19 toward the rotor 16. The plurality of teeth 18 are spaced apart at equal intervals around the circumferential direction of the stator 14. A flange portion 26 protruding on both sides in the circumferential direction is provided at the radially inner end of each tooth 18.

[0013] The winding 24 is an electrical conductor. The conductor may be a wire (conductor) selected from copper, aluminum, and the like. The winding 24 is wound around the slot 20 (teeth 18) multiple times to form one coil portion 30. The coil portions 30 are spaced apart in the circumferential direction of the stator 14. The stator 14 has a plurality of coil portions 30 for each of the U, V, and W phases. The coil portions 30 constituting the same phase are electrically connected in series. FIG. 1 shows one coil portion 30 for one of the U, V, and W phases as a representative example. While FIG. 1 illustrates distributed winding, in which one coil portion 30 is arranged across multiple slots 20, as an example of the winding method for the winding 24, concentrated winding, in which one coil portion 30 is arranged for each slot 20, may also be used.

[0014] The winding 24 is formed by bundling (overlapping) a plurality of unit windings 25 in the radial direction (R direction) of the stator 14. That is, the plurality of unit windings 25 are arranged along the radial direction of the stator 14. The plurality of unit windings 25 are electrically connected in parallel to one another. In FIG. 1, the winding 24 is divided into five unit windings 25.

[0015] Each unit winding 25 is formed by bundling a plurality of wires 250. The number of wires 250 constituting each of the plurality of unit windings 25 is the same. For example, if one winding 24 is made up of 300 wires 250, the number of wires 250 constituting each unit winding 25 is 60. The number of unit windings 25 (number of sections) constituting the winding 24 is not limited to five, and may be two or more.

[0016] When the number of the plurality of unit windings 25 is n, the plurality of unit windings 25 are arranged in order along the radial direction from the first unit winding 25a which is the first unit winding 25 to the nth unit winding 25 which is the nth unit winding 25. In this embodiment, the number of unit windings 25 is five, so the first unit winding 25a, the second unit winding 25b, the third unit winding 25c, the fourth unit winding 25d, and the fifth unit winding 25e are arranged in order along the radial direction.

[0017] One turn of the winding 24 is defined as one full turn of the winding 24 around the slot 20. Each coil portion 30 has multiple turns, since it is wound multiple times. Each turn has a first axial portion 34a and a second axial portion 34b. The first axial portion 34a and the second axial portion 34b extend in the axial direction (X direction) of the stator 14. The first axial portion 34a and the second axial portion 34b are spaced apart in the circumferential direction (C direction) of the stator 14. In one turn of the winding 24, the first axial portion 34a is one of a pair of winding regions extending in the axial direction of the stator 14. The first axial portion 34a belongs to the front half region of the turn. In one turn of the winding 24, the second axial portion 34b is the other of the pair of winding regions extending in the axial direction of the stator 14. The second axial portion 34b belongs to the rear half region of the turn.

[0018] In Figure 2, the R1 direction is the radially outward direction of the stator 14, and the R2 direction is the radially inward direction of the stator 14. Figure 2 representatively shows adjacent coil sections 30 in the same phase. The arrangement order of the multiple unit windings 25 in the radial direction of the stator 14 is reversed between adjacent coil sections 30 in the same phase. As described above, the stator 14 has multiple coil sections 30 for each of the U, V, and W phases. Therefore, the arrangement order of the multiple unit windings 25 in the radial direction is reversed between adjacent coil sections 30 in the U, V, and W phases.

[0019] Specifically, in one of the adjacent coil sections 30 (coil section 30a), the first unit winding 25a is located at the outermost position in the radial direction among the plurality of unit windings 25. In the other of the adjacent coil sections 30 (coil section 30b), the first unit winding 25a is located at the innermost position in the radial direction among the plurality of unit windings 25. The plurality of coil sections 30 respectively form a plurality of poles in the stator 14. Therefore, the coil section 30a and the coil section 30b are adjacent poles in the same phase. In this embodiment, the case where the number of unit windings 25 is five is exemplified. Therefore, the arrangement order of the first to fifth unit windings 25a to 25e will be described below.

[0020] For ease of understanding, in Fig. 2, the first to fifth unit windings 25a to 25e are denoted by symbols A to E, respectively. As shown in Fig. 2, in one coil section 30a, which is one of adjacent coil sections 30 in the same phase, the first to fifth unit windings 25a to 25e are arranged radially inward (R2) in this order. Therefore, in the coil section 30a, the first unit winding 25a is located at the outermost position in the radial direction among the first to fifth unit windings 25a to 25e. In the coil section 30a, the fifth unit winding 25e is located at the innermost position in the radial direction among the first to fifth unit windings 25a to 25e.

[0021] In the other coil section 30b of the adjacent coil sections 30 of the same phase, the first to fifth unit windings 25a to 25e are arranged radially outward (R1) in this order. Therefore, in the coil section 30b, the first unit winding 25a is located at the innermost position in the radial direction among the first to fifth unit windings 25a to 25e. In the coil section 30b, the fifth unit winding 25e is located at the outermost position in the radial direction among the first to fifth unit windings 25a to 25e.

[0022] 2, symbols A to E are assigned to only one representative turn of each coil section 30, but the arrangement order of the first to fifth unit windings 25a to 25e is the same for all turns in one coil section 30a, and the arrangement order of the first to fifth unit windings 25a to 25e is the same for all turns in the other coil section 30b.

[0023] The present embodiment configured as above has the following advantages.

[0024] During operation of the rotating electric machine 12 shown in FIG. 1, leakage magnetic flux occurs inside the rotating electric machine 12. When the leakage magnetic flux acts on the winding 24, an induced electromotive force is induced in each unit winding 25. The induced electromotive force increases as the magnetic flux density increases. Furthermore, the magnetic flux density of the leakage magnetic flux inside the rotating electric machine 12 increases radially inward. Therefore, if the induced electromotive forces that can be generated in the multiple unit windings 25 due to the leakage magnetic flux differ from one another depending on the relative positions of the unit windings 25, a potential difference occurs between the multiple unit windings 25, generating a circulating current.

[0025] Therefore, in the winding structure 10 of the rotating electric machine 12 according to this embodiment, the arrangement order of the plurality of unit windings 25 is reversed between the coil sections 30 adjacent to each other in the same phase. Referring to FIG. 3, the magnitude relationship of the potential difference that can be generated by the induced electromotive force due to the leakage magnetic flux is shown for the first to fifth unit windings 25a to 25e of the coil sections 30a, 30b adjacent to each other in the same phase. The magnitude relationship of the potential difference that can be generated by the induced electromotive force is shown as V1 <V2<V3<V4<V5である。

[0026] That is, in the coil section 30a, the induced electromotive force (potential difference that can be generated by the induced electromotive force) is smallest in the first unit winding 25a, and the induced electromotive force is largest in the fifth unit winding 25e. In the coil section 30b, the induced electromotive force is largest in the first unit winding 25a, and the induced electromotive force is smallest in the fifth unit winding 25e. As a result, the induced electromotive forces in the first to fifth unit windings 25a to 25e are equalized, and the generation of potential differences among the first to fifth unit windings 25a to 25e is prevented or suppressed. This makes it possible to prevent or suppress the generation of circulating current between adjacent coil sections 30 (between poles) in the same phase.

[0027] Fig. 4 shows a winding structure 10A according to a modified example. As with the winding structure 10 (Fig. 2), in the winding structure 10A according to the modified example shown in Fig. 4, the radial arrangement order of the multiple unit windings 25 is reversed between adjacent coil portions 30a, 30b in the same phase. In addition, in the winding structure 10A according to the modified example, the radial orientation of each of the unit windings 25 from the first unit winding 25a to the nth unit winding 25 is reversed by 180° between adjacent coil portions 30a, 30b in the same phase. In Fig. 4, the orientations of the symbols A to E in the coil portion 30b are upside down compared to the orientations of the symbols A to E in the coil portion 30a, indicating that the orientations of the unit windings 25 differ by 180° between the coil portions 30a, 30b.

[0028] This configuration also makes it possible to suppress potential differences between the wires 250 (see FIG. 1) in each unit winding 25. This makes it possible to more effectively prevent or suppress the occurrence of potential differences.

[0029] The following additional notes are further disclosed regarding the above embodiment.

[0030] (Appendix 1) The winding structure (10) of the rotating electric machine (12) of the present disclosure is formed by bundling a plurality of wires (250) together to form a unit winding (25), bundling a plurality of the unit windings together in the radial direction of a stator (14) of the rotating electric machine to form a winding (24), and winding the windings in a plurality of slots (20) formed between a plurality of teeth (18) of the stator that face a rotor (16), and the windings are wound in the plurality of slots to form a plurality of coil portions (30) that constitute the same phase, and the arrangement order of the plurality of unit windings in the radial direction is reversed between adjacent coil portions in the same phase.

[0031] With this configuration, the order of the unit windings is reversed between adjacent coil portions, so that potential differences between adjacent coil portions (between poles) in the same phase are canceled out, preventing or suppressing the generation of circulating currents, which in turn contributes to improved energy efficiency.

[0032] (Appendix 2) In the winding structure of the rotating electric machine described in Supplementary Note 1, the number of the plurality of unit windings is n, and the plurality of unit windings are arranged in order along the radial direction from a first unit winding (25a) that is the first unit winding to an nth unit winding that is the nth unit winding, and in one of the adjacent coil sections, the first unit winding may be located at the outermost position in the radial direction among the plurality of unit windings, and in the other of the adjacent coil sections, the first unit winding may be located at the innermost position in the radial direction among the plurality of unit windings.

[0033] (Appendix 3) In the winding structure of the rotating electric machine described in Supplementary Note 2, the orientation of each of the unit windings from the first unit winding to the nth unit winding with respect to the radial direction may be reversed by 180° between the coil portions adjacent to each other in the same phase.

[0034] This configuration also makes it possible to suppress the potential difference between the strands of each unit winding, thereby more effectively preventing or suppressing the generation of circulating current.

[0035] (Appendix 4) In the winding structure of a rotating electric machine according to any one of Supplementary Notes 1 to 3, the winding may have a plurality of turns in each of the plurality of slots by being wound around a plurality of times.

[0036] With this configuration, it is possible to prevent or suppress the generation of circulating current in the coil portion having multiple turns.

[0037] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0038] 10... Winding structure 12... Rotating electric machine 14... Stator 16... Rotor 18...Teeth 20...Slot 22... Stator core 24... Winding 25...Unit winding 30...Coil section

Claims

1. A winding structure for a rotating electric machine, in which a unit winding is formed by bundling a plurality of wires, a winding is formed by bundling a plurality of the unit windings in the radial direction of a stator of the rotating electric machine, and the winding is wound in a plurality of slots formed between a plurality of teeth of the stator that are provided opposite to a rotor, a plurality of coil portions constituting the same phase are formed by winding the winding wire around each of the plurality of slots, A winding structure for a rotating electric machine, wherein the arrangement order of the plurality of unit windings in the radial direction is reversed between adjacent coil portions of the same phase.

2. 2. The winding structure of a rotating electric machine according to claim 1, the number of the plurality of unit windings is n, the plurality of unit windings are arranged in order along the radial direction from a first unit winding that is the first unit winding to an n-th unit winding that is the n-th unit winding, In one of the coil portions adjacent to each other, the first unit winding is located outermost in the radial direction among the plurality of unit windings, A winding structure for a rotating electric machine, wherein, in the other of the adjacent coil portions, the nth unit winding is located radially innermost among the plurality of unit windings.

3. 3. The winding structure of a rotating electric machine according to claim 2, A winding structure for a rotating electric machine, wherein the orientation of each of the first to nth unit windings with respect to the radial direction is reversed by 180° between adjacent coil portions in the same phase.

4. The winding structure of a rotating electric machine according to any one of claims 1 to 3, A winding structure for a rotating electric machine, wherein the winding has a plurality of turns by being wound around a plurality of times in each of the plurality of slots.

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