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 combination of the plurality of coil portions 30 in the same phase with respect to the relative position of each unit winding 25 in the plurality of unit windings 25 is the same between the plurality of unit windings 25.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 a 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 a rotor, and a plurality of coil sections that constitute the same phase are formed by winding the windings into the plurality of slots, respectively, and the combination of the relative positions of each unit winding among the plurality of unit windings across the plurality of coil sections in the same phase is the same among the plurality of unit windings. [Effects of the Invention]

[0007] According to the winding structure of the rotating electric machine of the present invention, when the multiple coil sections in the same phase are viewed as a whole, the positions of the multiple unit windings are all equivalent, so that potential differences across the multiple coil sections in the same phase are canceled out, making it possible to prevent or suppress the generation of circulating currents. [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. The winding 24 is divided into n unit windings 25, the number of which corresponds to the number of coil portions 30 in the same phase. In this embodiment, the number of coil portions 30 in the same phase is assumed to be four. For this reason, in FIG. 1 , the winding 24 is divided into four 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 and the winding is divided into four unit windings 25, the number of wires 250 constituting each unit winding 25 is 75.

[0016] When the number of the plurality of unit windings 25 is n, the plurality of unit windings 25 includes a first unit winding 25a which is the first unit winding 25, through an nth unit winding 25 which is the nth unit winding 25. In this embodiment, the number of unit windings 25 is four, and therefore the winding 24 includes a first unit winding 25a, a second unit winding 25b, a third unit winding 25c, and a fourth unit winding 25d. The first unit winding 25a, the second unit winding 25b, the third unit winding 25c, and the fourth unit winding 25d are located at mutually different radial relative positions in the winding 24.

[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 FIG. 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. FIG. 2 shows a plurality of coil sections 30 (coil sections 30a to 30d) in the same phase. The combination of the relative positions of the unit windings 25 among the plurality of unit windings 25 across the plurality of coil sections 30 in the same phase is the same across the plurality of unit windings 25. As described above, the stator 14 has a plurality of coil sections 30 for each of the U-phase, V-phase, and W-phase. Therefore, in the U-phase, the combination of the relative positions of the unit windings 25 among the plurality of unit windings 25 across the plurality of coil sections 30 in the same phase is the same across the plurality of unit windings 25. The same is true for the V-phase and the W-phase.

[0019] In the multiple coil sections 30 of the same phase, there are n possible combinations of the arrangement order of the unit windings 25. When one of the multiple coil sections 30 adjacent to each other is designated as a first coil section and the other as a second coil section, in the first coil section, the first unit winding 25a is located at the outermost position in the radial direction, and the nth unit winding 25 is located at the innermost position in the radial direction. In the second coil section, the nth unit winding 25 is located at the outermost position in the radial direction, and the other unit windings 25 are sequentially shifted by one position relative to the corresponding unit winding 25 in the first coil section.

[0020] The multiple coil portions 30 respectively form multiple poles in the stator 14. Therefore, coil portion 30a and coil portion 30b are adjacent poles in the same phase. Coil portion 30b and coil portion 30c are adjacent poles in the same phase. Coil portion 30c and coil portion 30d are adjacent poles in the same phase. Furthermore, coil portion 30d and coil portion 30a are adjacent poles in the same phase. In this embodiment, a case is illustrated in which the number of unit windings 25 divided into multiple sections in the winding 24 is four. Therefore, the arrangement order of the first to fourth unit windings 25a to 25d will be described below.

[0021] For ease of understanding, in Fig. 2, the first to fourth unit windings 25a to 25d are assigned symbols A to D, respectively. As shown in Fig. 2, in the first coil section 30a, the first to fourth unit windings 25a to 25d are arranged in this order radially inward (R2). 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 fourth unit windings 25a to 25d. In the coil section 30a, the fourth unit winding 25d is located at the innermost position in the radial direction among the first to fourth unit windings 25a to 25d.

[0022] In the second coil portion 30b, the fourth unit winding 25d is located at the outermost position in the radial direction, and the other unit windings 25a to 25c are sequentially shifted by one unit winding from the corresponding unit windings 25 in the first coil portion 30a. That is, in the coil portion 30b, the third unit winding 25c is located at the innermost position in the radial direction among the first to fourth unit windings 25a to 25d, and the fourth unit winding 25d, the first unit winding 25a, and the second unit winding 25b are arranged in this order radially inward.

[0023] In the third coil portion 30c, the third unit winding 25c is located at the outermost position in the radial direction, and the other unit windings 25a, 25b, 25d are sequentially shifted by one position relative to the corresponding unit windings 25 in the second coil portion 30b. That is, in the coil portion 30c, the second unit winding 25b is located at the innermost position in the radial direction among the first to fourth unit windings 25a to 25d, and the third unit winding 25c, the fourth unit winding 25d, and the first unit winding 25a are arranged in this order radially inward.

[0024] In the fourth coil portion 30d, the second unit winding 25b is located at the outermost position in the radial direction, and the other unit windings 25a, 25c, 25d are sequentially shifted by one position relative to the corresponding unit windings 25 in the third coil portion 30c. That is, in the coil portion 30d, the first unit winding 25a is located at the innermost position in the radial direction among the first to fourth unit windings 25a to 25d, and the second unit winding 25b, the third unit winding 25c, and the fourth unit winding 25d are arranged in this order radially inward.

[0025] As shown in FIG. 2, the combinations of the relative positions of each unit winding 25 among the first to fourth unit windings 25a to 25d across the multiple coil portions 30a to 30d in the same phase (U phase, V phase, or W phase) are all A+B+C+D, which is the same among the first to fourth unit windings 25a to 25d.

[0026] 2, symbols A to D are assigned to only one representative turn of each coil section 30, but the arrangement order of the first to fourth unit windings 25a to 25d is the same for all turns in the first coil section 30a. Also, the arrangement order of the first to fourth unit windings 25a to 25d is the same for all turns in each of the other coil sections 30b to 30d.

[0027] The present embodiment configured as above has the following advantages.

[0028] 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 (in the R2 direction). Therefore, if the induced electromotive forces that can be generated due to the leakage magnetic flux in the multiple unit windings 25 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.

[0029] Therefore, according to the winding structure 10 of the rotating electric machine 12 of this embodiment, the combination of the relative positions of the unit windings 25 among the plurality of unit windings 25 across the plurality of coil sections 30 in the same phase (U phase, V phase, or W phase) is the same among the plurality of unit windings 25. Here, 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 fourth unit windings 25a to 25d of the plurality of coil sections 30 (four coil sections 30a to 30d) in the same phase. The magnitude relationship of the potential difference that can be generated by the induced electromotive force is V1 <V2<V3<V4である。

[0030] That is, in the first coil section 30a, the induced electromotive force (potential difference that can be generated by the induced electromotive force) in the first unit winding 25a is the smallest, and the induced electromotive force in the fourth unit winding 25d is the largest. In the second coil section 30b, the induced electromotive force in the fourth unit winding 25d is the smallest, and the induced electromotive force in the third unit winding 25c is the largest. In the third coil section 30c, the induced electromotive force in the third unit winding 25c is the smallest, and the induced electromotive force in the second unit winding 25b is the largest. In the fourth coil section 30d, the induced electromotive force in the second unit winding 25b is the smallest, and the induced electromotive force in the first unit winding 25a is the largest.

[0031] Therefore, the combination of potential differences that can be generated by induced electromotive forces in the unit windings 25a-25d across the coil sections 30a-30d in the same phase is V1+V2+V3+V4, which is the same across the unit windings 25a-25d. As a result, when the coil sections 30a-30d in the same phase are viewed as a whole, the positions of the unit windings 25a-25d are all equivalent, and the induced electromotive forces in the unit windings 25a-25d are equalized. This makes it possible to prevent or suppress the generation of circulating current across the coil sections 30 in the same phase.

[0032] A winding structure 10A according to a modified example is shown in Fig. 4. As with the winding structure 10 (Fig. 2), in the winding structure 10A according to the modified example shown in Fig. 4, the combinations of the relative positions of the unit windings 25 among the multiple unit windings 25 across the multiple coil portions 30a-30d in the same phase are all A+B+C+D, which is the same among the multiple unit windings 25a-25d. Therefore, the winding structure 10A according to the modified example can also prevent or suppress the generation of circulating current.

[0033] The following additional notes are further disclosed regarding the above embodiment.

[0034] (Appendix 1) The winding structure (10) of the rotating electric machine (12) of the present disclosure is a winding structure of the rotating electric machine formed by bundling a plurality of wires (250) together to form a unit winding (25), bundling a plurality of the unit windings 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 are provided opposite a rotor (16), and by winding the windings in the plurality of slots, a plurality of coil portions (30) that constitute the same phase are formed, and the combination of the relative positions of each unit winding among the plurality of unit windings across the plurality of coil portions in the same phase is the same among the plurality of unit windings.

[0035] With this configuration, when the multiple coil sections in the same phase are viewed as a whole, the positions of the multiple unit windings are all equivalent, so that potential differences across the multiple coil sections in the same phase are canceled out, making it possible to prevent or suppress the generation of circulating currents.

[0036] (Appendix 2) In the winding structure of the rotating electric machine described in Supplementary Note 1, the winding is divided into n unit windings corresponding to the number of the plurality of coil portions in the same phase, and the plurality of unit windings may include a first unit winding (25a) that is the first unit winding to an nth unit winding that is the nth unit winding, and there may be n combinations of the arrangement order of the plurality of unit windings.

[0037] With this configuration, it is possible to easily realize a configuration in which the positions of the plurality of unit windings are all equivalent across the plurality of coil sections as a whole.

[0038] (Appendix 3) In the winding structure of a rotating electric machine described in Supplementary Note 2, when one of the adjacent coil sections in the plurality of coil sections is a first coil section and the other is a second coil section, in the first coil section, the first unit winding is located at the outermost position in the radial direction and the nth unit winding is located at the innermost position in the radial direction, and in the second coil section, the nth unit winding is located at the outermost position in the radial direction, and the other unit windings may be located at positions sequentially shifted by one with respect to the corresponding unit winding in the first coil section.

[0039] With this configuration, during the manufacturing process of the stator, when winding the winding from one slot to the next, the position of the unit winding is sequentially shifted by one, making it possible to easily form a winding structure in which the positions of the multiple unit windings are all equivalent throughout the multiple coil sections.

[0040] (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.

[0041] With this configuration, it is possible to prevent or suppress the generation of circulating current in the coil portion having multiple turns.

[0042] 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]

[0043] 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 of a rotating electric machine, wherein a combination of relative positions of each unit winding among the plurality of unit windings across the plurality of coil sections in the same phase is the same among the plurality of unit windings.

2. 2. The winding structure of a rotating electric machine according to claim 1, the winding is divided into n unit windings corresponding to the number of the plurality of coil portions in the same phase, the plurality of unit windings include a first unit winding that is the first unit winding to an n-th unit winding that is the n-th unit winding, A winding structure for a rotating electric machine, in which there are n combinations of the arrangement order of the plurality of unit windings.

3. 3. The winding structure of a rotating electric machine according to claim 2, When one of the coil portions adjacent to each other is a first coil portion and the other is a second coil portion, In the first coil portion, the first unit winding is located at the outermost position in the radial direction, and the nth unit winding is located at the innermost position in the radial direction, A winding structure of a rotating electric machine, wherein in the second coil portion, the nth unit winding is located at the outermost position in the radial direction, and the other unit windings are located at positions sequentially shifted by one with respect to the corresponding unit winding in the first coil portion.

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.

Images