A dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings

Abstract

The application provides a dual-stator axial flux permanent magnet motor with dual three-phase star-angle hybrid windings, and belongs to the technical field of motors. The dual-stator axial flux permanent magnet motor comprises a stator A, a rotor and a stator B, the stator A and the stator B are arranged on the two sides of the rotor, the stator A and the stator B are spatially staggered by an electric angle θ=15°, each stator comprises three-phase star windings and three-phase angle windings which are sequentially staggered by an electric angle β=30° in space, the star windings are connected to the three vertices of the angle windings, the stator A and the stator B each contain six-phase windings, each stator presents three-phase to the outside, and the winding currents of the corresponding phases in the stator A and the stator B are staggered by an angle φ=15° in time. The dual three-phase star-angle hybrid winding motor constructed by the application has the characteristics of low harmonic content of twelve-phase motor, and has the advantages of low torque ripple and low vibration noise.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, and particularly relates to a dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings. Background Technology

[0002] Dual-stator axial flux motors offer advantages such as good heat dissipation, high power density, and a flat structure, making them suitable for high-power-density, low-noise applications like electric vehicles and ship bilge pumps. However, traditional three-phase dual-stator axial flux motors suffer from significant torque fluctuations and do not meet the requirements for high-reliability, fault-tolerant operation. Multiphase motors (such as 12-phase or 15-phase motors) feature high power density and low torque fluctuations, while also enabling redundant, fault-tolerant operation. However, multiphase motors place higher demands on frequency converters; the more phases, the more complex the frequency converter design becomes. Furthermore, multiphase motors require specific coordination between the number of poles and slots; the more phases, the fewer pole-slot combinations are available.

[0003] To reduce the problem of large harmonics in the armature winding magnetomotive force during fault-tolerant operation of motors, a patent (patent number ZL202210144695.5) proposes a dual m-phase winding separated type asymmetric axial flux permanent magnet motor. This motor consists of two multi-phase stators and has the characteristics of more pole slot selection schemes, low torque ripple, and low rotor eddy current loss. However, this type of multi-phase motor has the following problems: 1) The number of phases increases the design difficulty of the frequency converter driver; 2) There are more power supply terminals.

[0004] The aforementioned technical problems still need to be further solved. To address this, the present invention provides a dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings. Summary of the Invention

[0005] This invention provides a dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings to solve the technical problems existing in the prior art: (1) the number of phases increases the design difficulty of the frequency converter driver; (2) there are more power supply terminals.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] The present invention provides a dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings, including a housing, and a rotating assembly, an end cover assembly, stator A and stator B are arranged inside the housing. The rotating assembly passes through the middle of the end cover assembly, and stator A and stator B are symmetrically arranged inside the end cover assembly.

[0008] Stator A includes stator core A, star winding A, and delta winding A. Stator slot A is opened on stator core A. Both star winding A and delta winding A are placed in stator slot A. Both star winding A and delta winding A are three-phase symmetrical windings. The star winding A and delta winding A are successively phased by β = 30° electrical angle in the circumferential direction. The three phases of star winding A are respectively connected to the three vertices of delta winding A.

[0009] Stator B includes stator core B, star winding B, and delta winding B. Stator slot B is opened on stator core B. Both star winding B and delta winding B are placed in stator slot B. Both star winding B and delta winding B are three-phase symmetrical windings. The star winding B and delta winding B are successively phased by β = 30° electrical angle in the circumferential direction. The three phases of star winding B are respectively connected to the three vertices of delta winding B.

[0010] Optionally, stator A and stator B are offset by θ = 15° electrical angle along the circumferential direction; the windings of stator A and stator B present three phases to the outside.

[0011] Optionally, the number of turns N of the star-connected winding A in stator A. 1Y The number of turns N of the delta winding A 1△ The relationship is The number of turns N of the star winding B in stator B 3Y The number of turns N of the delta winding B 3△ The relationship is

[0012] Optionally, the end cover assembly includes end cover A and end cover B, both of which are fixed to the housing; the rotating assembly includes a rotor, bearings, and a rotating shaft, wherein the rotor is fixed to the rotating shaft, and there are gaps between the rotor and stator A, stator B, and the housing, and the rotating shaft is rotatably engaged with end cover A, which is fixed to stator A, and end cover B, which is fixed to stator B, through the bearings.

[0013] Optionally, the rotor includes a permanent magnet and a rotor disk. The rotor disk has magnetic pole mounting holes, and the permanent magnet is embedded in the magnetic pole mounting holes. The magnetization directions d of two adjacent permanent magnets are opposite.

[0014] Optionally, the rotor disk is made of a non-magnetic material.

[0015] Compared with the prior art, the advantages and effects of the present invention are as follows:

[0016] (1) The dual three-phase star-angle hybrid winding dual stator axial flux permanent magnet motor proposed in this invention has the characteristics of a twelve-phase motor and eliminates the low-order armature magnetomotive force harmonics of the 5th, 7th, 11th and 13th orders.

[0017] (2) The dual three-phase star-delta hybrid winding dual stator axial flux permanent magnet motor proposed in this invention has three-phase external terminals for each stator, which simplifies the motor's lead wires;

[0018] (3) The dual three-phase star-delta hybrid winding dual stator axial flux permanent magnet motor proposed in this invention has high average output torque and low torque fluctuation. Attached Figure Description

[0019] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:

[0020] Figure 1 This is a three-dimensional diagram of the dual-stator axial flux permanent magnet motor with dual-three-phase star-delta hybrid windings of the present invention.

[0021] Figure 2 This is diagram A of the stator of the dual-stator axial flux permanent magnet motor with dual-three-phase star-delta hybrid windings of the present invention;

[0022] Figure 3 This is a unit motor development diagram of the dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings of the present invention.

[0023] Figure 4 This is a diagram of the dual-three-phase star-delta hybrid winding of the dual-stator axial flux permanent magnet motor of the present invention;

[0024] Figure 5 This is a rotor structure diagram of the dual-stator axial flux permanent magnet motor with dual-three-phase star-delta hybrid windings of the present invention;

[0025] Figure 6 This is a spectrum diagram of the armature magnetic field of the motor of the present invention;

[0026] Figure 7 This is an electromagnetic torque diagram of the motor of the present invention.

[0027] Explanation of icon numbers:

[0028] 1-Stator A; 2-Rotor; 3-Stator B; 4-Bearing; 5-Shaft; 6-End cover A; 7-End cover B; 8-Casing; 11-Stator core A; 12-Star winding A; 13-Delta winding A; 14-Stator slot A; 21-Permanent magnet; 22-Rotor disc; 23-Magnetic pole mounting hole; 31-Stator core B; 32-Star winding B; 33-Delta winding B; 34-Stator slot B. Detailed Implementation

[0029] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Unless otherwise specified, the techniques used in the embodiments are conventional means well known to those skilled in the art.

[0030] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should be understood in their ordinary sense by those skilled in the art. In this document, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms “connected,” “linked,” etc., should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate medium. The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase “comprising…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] This embodiment provides a dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings, such as... Figures 1 to 7 As shown, it includes: a housing 8, inside which are arranged a rotating assembly, an end cover assembly, a stator A 1 and a stator B 3, the rotating assembly passing through the middle of the end cover assembly, and the stator A 1 and stator B 3 symmetrically arranged inside the end cover assembly;

[0032] Stator A1 includes stator core A11, star winding A12, and delta winding A13. Stator slot A14 is opened on stator core A11. Both star winding A12 and delta winding A13 are placed in stator slot A14. Both star winding A12 and delta winding A13 are three-phase symmetrical windings. The star winding A12 and delta winding A13 are successively phased by β = 30° electrical angle in the circumferential direction. The three phases of star winding A12 are respectively connected to the three vertices of delta winding A13. The winding arrangement and connection method in stator A1 only have 12j+1 harmonics, j = 0, ±1, ±2..., which eliminates the 5th, 7th and other low-order harmonics in three-phase motors.

[0033] Stator B3 includes stator core B31, star winding B32, and delta winding B33. Stator core B31 has stator slots B34. Both star winding B32 and delta winding B33 are placed in stator slots B34. Both star winding B32 and delta winding B33 are three-phase symmetrical windings. The star winding B32 and delta winding B33 are successively phased by β = 30° electrical angle in the circumferential direction. The three phases of star winding B32 are respectively connected to the three vertices of delta winding B33. The winding arrangement and connection method in stator B3 only have 12j+1 harmonics, j = 0, ±1, ±2..., eliminating the 5th and 7th harmonics in three-phase motors.

[0034] For example, such as Figure 1 As shown, the present invention provides a dual three-phase star-delta hybrid winding dual-stator axial flux permanent magnet motor, including stator A1, rotor 2, stator B3, bearing 4, shaft 5, end cover A6, end cover B7, and housing 8. Stator A1 is fixed on end cover A6, stator B3 is fixed on end cover B7, end cover A6 and end cover B6 are fixed on both sides of housing 7, rotor 2 is fixed on shaft 5, stator A1 and stator B3 are mirror images placed on both sides of rotor 2, and one of the stators is rotated along the circumferential direction by a certain angle. There are gaps between rotor 2 and stator A1, stator B3 and housing 5. Shaft 5 is rotatably engaged with end cover A6 where stator A1 is fixed and end cover B7 where stator B3 is fixed through bearing 4.

[0035] like Figure 2 and Figure 3 As shown, stator A1 includes stator core A11, star winding A12, and delta winding A13. Stator slot A14 is opened on stator core A11, and both star winding A12 and delta winding A13 are placed within stator slot A14. Star winding A12 includes A... 1Y B 1Y C 1Y -A 1Y -B 1Y -C 1Y A 1Y With -A 1Y A represents 1Y The two sides of the phase coil (Note: For ease of description, one side of the coil is used to represent one phase, i.e., A) 1Y Representing A 1Y With -A 1Y The coil consists of two phases (B and C phases are treated the same), B 1Y With -B 1Y B 1Y The two sides of the phase coil, C 1Y With -C 1Y Indicate C 1Y The two sides of the phase coil, the delta-connected winding A13 includes A1△ B 1△ C 1△ -A 1△ -B 1△ -C 1△ A 1△ With -A 1△ A represents 1△ The two sides of the phase coil, B 1△ With -B 1△ B 1△ The two sides of the phase coil, C 1△ With -C 1△ Indicate C 1△ The corresponding phases of the two sides of the phase coil, in the star-connected winding A12 and the delta-connected winding A13, are successively out of phase by β = 30° electrical angle in the circumferential direction. Figure 3 It is a 12-slot 2-pole motor (for) Figure 2 The unfolded diagram of a 48-slot 8-pole motor (which contains four unit motors) shows that the slot pitch angle for each unit motor is 360° / 12 = 30°. Therefore, A 1Y B 1Y C 1Y With A 1△ B 1△ C 1△ They are separated by one slot, and their electrical angles differ by 30° in the circumferential direction; both the star-connected winding A12 and the delta-connected winding A13 are three-phase symmetrical windings, that is, A 1Y B 1Y C 1Y The three phases are spatially separated by 120° electrical degrees. A 1△ B 1△ C 1△ The three phases are 120° electrical degrees apart in the circumferential direction; for example... Figure 4 As shown, A 1△ B 1△ C 1△ The three-phase windings are connected end to end in sequence to form a triangle. The three phases of the star winding A12 are respectively connected to the three vertices of the delta winding A13.

[0036] like Figure 3 As shown, stator B3 includes stator core B31, star winding B32, and delta winding B22. Stator core B31 has stator slots B34. Both star winding B32 and delta winding B33 are placed in stator slots B34. Both star winding B32 and delta winding B33 are three-phase symmetrical windings (the three-phase symbol for star winding B32 is A). 3Y B 3Y C 3Y The symbol for the three-phase delta winding B33 is A. 3△ B 3△ C3△ In the star-connected winding B32 and the delta-connected winding B33, the corresponding phases are successively out of phase by β = 30° electrical angle in the circumferential direction; for example... Figure 4 As shown, A 3△ B 3△ C 3△ The three-phase windings are connected end to end in sequence to form a triangle. The three phases of the star winding B32 are respectively connected to the three vertices of the angle winding B33.

[0037] In one possible embodiment, such as Figure 3 As shown, stator A1 and stator B3 are offset by θ = 15° electrical angle in the circumferential direction; the windings of stator A and stator B present three phases to the outside.

[0038] For example, the stator A1 and stator B3 on both sides of rotor 2 are offset by θ = 15° electrical angle in the circumferential direction; such as Figure 4 As shown, the windings of stator A1 and stator B3 are three-phase. The three-phase output terminals of stator A1 are A1, B1, and C1, and the three-phase output terminals of stator B3 are A3, B3, and C3.

[0039] In one possible embodiment, such as Figure 1 As shown, the number of turns N of the star-connected winding A12 in stator A1 is... 1Y The number of turns N of the angle-connected winding A13 1△ The relationship is The number of turns N of the star-connected winding B32 in stator B3 3Y The number of turns N of the angle-connected winding B33 3△ The relationship is

[0040] For example, such as Figure 2 , Figure 3 and Figure 4 As shown, the number of turns N of the star-connected winding A12 in stator A1 is... 1Y The number of turns N of the angle-connected winding A13 1△ The relationship is The number of turns N of the star-connected winding B32 in stator B3 3Y The number of turns N of the angle-connected winding B33 3△ The relationship is

[0041] In one possible embodiment, such as Figure 1 As shown, the end cover assembly includes end cover A 6 and end cover B 7, both of which are fixed to the housing 8; the rotating assembly includes rotor 2, bearing 4 and rotating shaft 5, wherein rotor 2 is fixed to rotating shaft 5, and there are gaps between rotor 2 and stator A 1, stator B 3 and housing 8, and rotating shaft 5 is rotatably engaged with end cover A 6, which is fixed to stator A 1 and end cover B 7, which is fixed to stator B 3, through bearing 4.

[0042] In one possible embodiment, such as Figure 1 As shown, the rotor 2 includes a permanent magnet 21 and a rotor disk 22. A magnetic pole mounting hole 23 is opened on the rotor disk 22, and the permanent magnet 21 is embedded in the magnetic pole mounting hole 23. The magnetization directions d of two adjacent permanent magnets 21 are different.

[0043] For example, such as Figure 5 As shown, the rotor 2 includes a permanent magnet 21 and a rotor disk 22. A magnetic pole mounting hole 23 is opened on the rotor disk 22. The permanent magnet 21 is embedded in the magnetic pole mounting hole 23. The magnetization directions d of two adjacent permanent magnets 21 are opposite. In this embodiment, eight permanent magnets 21 are provided, indicating that the motor is an eight-pole motor.

[0044] In one possible embodiment, such as Figure 5 As shown, rotor disk 22 is made of non-magnetic material.

[0045] like Figure 1 , Figure 2 and Figure 3 As shown, the number of stator slots A14 on stator core A11 is equal to the number of stator slots B34 on stator core B31. The number of slots S of the example motor in the figure is 48, and the number of pole pairs p is 4 (the number of poles is 2p = 8).

[0046] like Figure 3 As shown, the number of slots occupied by star winding A12, delta winding A13, star winding B32, and delta winding B33 are all equal.

[0047] like Figure 3 As shown, Figure 3 The winding layout diagram of one unit motor of a 48-slot 8-pole motor is shown. The winding layout diagrams of the other three unit motors are as follows. Figure 3 Completely identical, the two sides of the star-connected winding A12, the delta-connected winding A13, the star-connected winding B32, and the delta-connected winding B33 all have a span of six slots (the pole pitch of a 12-slot 2-pole motor is six slots), so they are full-pitch windings. The pitch factor of a full-pitch winding is 1, and the winding is fully utilized. This is different from the short-pitch windings used in three-phase motors to reduce the 5th and 7th harmonics, whose pitch factor is less than 1. Therefore, the motor in this embodiment has a larger output torque under the same current.

[0048] like Figure 3 and Figure 4 As shown, A 1△ A 3△ A 1Y A 3Y The windings are successively phased by an electrical angle θ = 15°. Assume that A 1△ If the winding is 0°, then A 3△ The winding is located at -15°, A 1YThe winding is located at -30°, A 3Y The winding is located at -45°; according to circuit knowledge, A 1△ The current phase in the winding leads A 1Y Winding 30° electrical angle, A 3△ The current phase in the winding leads A 3Y The winding has an electrical angle of 30°. Assume A 1Y The initial phase of the current in the winding is -30°, A 3Y If the initial phase of the current in the winding is -45°, then A 1△ If the current phase in the winding is 0°, then A 3△ The current phase in the winding is -15°; similarly, the spatial position of the windings and the current phase of other phases have a similar relationship; it can be seen that if Figure 4 The currents at the corresponding winding ports A1 and A3, B1 and B3, and C1 and C3 in stator A1 and stator B3 are out of phase in time. According to the theory of motor windings, the motor in this embodiment can achieve the same effect as a twelve-phase motor, thereby eliminating low-order harmonics such as 5th, 7th, 11th, and 13th.

[0049] The relationship model between the number of poles and the number of slots of the motor in this embodiment is: q = S / 6p = 2k (k = 1, 2, 3, ...), where S represents the number of slots of any stator in the motor, p represents the number of pole pairs of the motor, and q is a non-zero even number. Figure 1 , Figure 2 and Figure 3 This refers to q = 2 (q = S / 6p = 48 / (6 × 4) = 2), A 1Y B 1Y C 1Y -A 1Y -B 1Y -C 1Y A 1△ B 1△ C 1△ -A 1△ -B 1△ -C 1△ And A 3Y B 3Y C 3Y -A 3Y -B 3Y -C 3Y A 3△ B 3△ C 3△ -A 3△ -B 3△ -C 3△ Each slot occupies a continuous slot; if q = 4 (assuming a 24-slot 2-pole motor), A 1Y B 1Y C1Y -A 1Y -B 1Y -C 1Y A 1△ B 1△ C 1△ -A 1△ -B 1△ -C 1△ And A 3Y B 3Y C 3Y -A 3Y -B 3Y -C 3Y A 3△ B 3△ C 3△ -A 3△ -B 3△ -C 3△ Each coil occupies two slots consecutively, and the span between the two sides of each coil is twelve slots (the pole pitch of a 24-slot 2-pole motor is twelve slots).

[0050] A 1△ A 3△ A 1Y A 3Y The windings are successively phased by an electrical angle of θ = 15°, which can cancel out some harmonics in stator A1 and stator B3, such as the 11th and 13th harmonics. In the end, only the 24j+1th harmonic exists in the air gap of the motor, j = 0, ±1, ±2...

[0051] Figure 6 This is the armature reaction magnetic field spectrum obtained by finite element simulation of the motor in this embodiment. It can be seen that, compared with the traditional 3-phase motor, the 5th, 7th, 11th and 13th harmonics are eliminated.

[0052] Figure 7 The results are finite element simulations of the electromagnetic torque of the motor in this embodiment. As can be seen, compared with the traditional three-phase motor, the average electromagnetic torque increases by about 5.5%, while the torque fluctuation is greatly reduced.

[0053] The dual three-phase star-delta hybrid winding dual-stator axial flux permanent magnet motor provided in this embodiment eliminates low-order armature magnetomotive force harmonics, reduces the design difficulty of the frequency converter driver, has more pole and slot selection options, and has the advantages of large output torque and low torque ripple.

[0054] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings, comprising a housing (8), wherein a rotating assembly, an end cover assembly, stator A (1) and stator B (3) are disposed inside the housing (8), the rotating assembly is disposed in the middle of the end cover assembly, and stator A (1) and stator B (3) are symmetrically disposed inside the end cover assembly, characterized in that: Stator A (1) includes stator core A (11), star winding A (12), and delta winding A (13). Stator slot A (14) is opened on stator core A (11). Star winding A (12) and delta winding A (13) are both placed in stator slot A (14). Star winding A (12) and delta winding A (13) are both three-phase symmetrical windings. Star winding A (12) and delta winding A (13) are successively phased by β=30° electrical angle in the circumferential direction. The three phases of star winding A (12) are respectively connected to the three vertices of delta winding A (13). Stator B (3) includes stator core B (31), star winding B (32), and delta winding B (33). Stator slot B (34) is opened on stator core B (31). Star winding B (32) and delta winding B (33) are both placed in stator slot B (34). Star winding B (32) and delta winding B (33) are both three-phase symmetrical windings. Star winding B (32) and delta winding B (33) are 30° electrical angles apart in the circumferential direction. The three phases of star winding B (32) are respectively connected to the three vertices of delta winding B (33). Stator A (1) and Stator B (3) are offset by θ = 15° electrical angle along the circumferential direction; the windings of Stator A (1) and Stator B (3) present three phases to the outside.

2. The dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings according to claim 1, characterized in that: The number of turns N of the star-connected winding A (12) in stator A (1) 1Y The number of turns N of the angle-connected winding A (13) 1△ The relationship is N 1△ = N 1Y The number of turns N of the star-connected winding B (32) in stator B (3) 3Y The number of turns N of the angle-connected winding B (33) 3△ The relationship is N 3△ = N 3Y .

3. The dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings according to claim 1, characterized in that: The end cap assembly includes end cap A (6) and end cap B (7), both of which are fixed to the housing (8); The rotating assembly includes a rotor (2), a bearing (4) and a rotating shaft (5). The rotor (2) is fixed on the rotating shaft (5). There are gaps between the rotor (2) and stator A (1), stator B (3) and the housing (8). The rotating shaft (5) rotates with end cap A (6) which is fixed with stator A (1) and end cap B (7) which is fixed with stator B (3) through the bearing (4).

4. The dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings according to claim 3, characterized in that, The rotor (2) includes a permanent magnet (21) and a rotor disk (22). A magnetic pole mounting hole (23) is opened on the rotor disk (22). The permanent magnet (21) is embedded in the magnetic pole mounting hole (23). The magnetization directions of two adjacent permanent magnets (21) are different.

5. The dual-stator axial flux permanent magnet motor with dual three-phase star-delta hybrid windings according to claim 4, characterized in that, The rotor disk (22) is made of non-magnetic material.

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