A hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor

Abstract

The present invention discloses a hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor, which relates to the field of flux switching motors, comprising a coaxially mounted first rotor, a first stator, a magnetic separator, a second stator and a second rotor, wherein an air gap exists between the first rotor and the first stator, and an air gap exists between the second rotor and the second stator. The structure of the first rotor, the first stator, the second rotor and the second stator is a salient pole structure, and the first rotor, the first stator, the second rotor and the second stator are symmetrically arranged about the magnetic separator. At the same time, when the present invention is in use, the permanent magnet is arranged on the rotor, thereby improving the torque density and power density, enhancing the torque capacity of the motor under overload conditions, and reducing the cogging torque of the motor. The air gap side boundary of the permanent magnet is in the shape of a third-order inverse cosine curve, the air gap boundary of the stator tooth is in the shape of an inverse cosine curve, and auxiliary slots are provided on the stator fault-tolerant teeth, which can effectively weaken the air gap magnetic field harmonics that generate cogging torque, thereby reducing torque pulsation.

Description

Technical Field

[0001] The present invention relates to the field of flux switching motors, in particular to a hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) can be categorized as surface-mounted and internal-mounted based on the location of their permanent magnets. Traditional surface-mounted PMSMs have their permanent magnets located on the rotor surface. This increases the air gap length, increases the motor's volume, weakens the air gap flux density, and reduces the motor's torque density. Internal-mounted PMSMs have their permanent magnets located within the stator, which compromises the motor's mechanical strength, hinders high-speed operation, increases manufacturing complexity, and hinders heat dissipation from the permanent magnets. Furthermore, the stator location of the permanent magnets significantly compresses the armature winding slot area, leading to severe magnetic saturation of the stator teeth. This increases the harmonic content of the air gap flux density and reduces its sinusoidality. This also dramatically increases copper loss in the motor windings and stator losses, weakening the motor's torque capability under overload conditions and causing significant overall motor heat generation, negatively impacting its service life and reliability. Summary of the Invention

[0003] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke permanent magnet motor. The present invention aims to solve the problems existing in the prior art of the stator permanent magnet hybrid excitation motor, such as large cogging torque, large output torque fluctuation, poor overload capacity, and low heat dissipation efficiency.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor, comprising a first rotor, a first stator, a magnetic separator, a second stator and a second rotor coaxially mounted;

[0006] There is an air gap between the first rotor and the first stator, and there is an air gap between the second rotor and the second stator. The structure of the first rotor, the first stator, the second rotor and the second stator is a salient pole structure. The first rotor, the first stator, the second rotor and the second stator are respectively located on both sides of the partition disk and are symmetrically arranged relative to the partition disk.

[0007] Furthermore, the first rotor and the second rotor include a rotor module unit and a rotor fixing disk, the rotor module unit includes a first rotor pole, a second rotor pole and a permanent magnet, the first rotor pole and the second rotor pole have the same structure, the permanent magnet is arranged between the first rotor pole and the second rotor pole, the boundary between the first rotor pole and the second rotor pole close to the air gap side is a third-order inverse cosine curve, and the rotor module units are evenly distributed along the circumference outside the rotor fixing ring.

[0008] Furthermore, the first stator and the second stator include a stator core, an armature winding and a magnetic tuning winding, the stator core includes stator armature teeth, stator fault-tolerant teeth and a stator yoke, the boundary of the stator armature teeth close to the air gap side is an inverse cosine curve, the boundary of the stator fault-tolerant teeth close to the air gap side is an inverse cosine function and an auxiliary slot is opened in the center, and the stator armature teeth and the stator fault-tolerant teeth are evenly and alternately distributed along the circumference of the stator yoke.

[0009] Furthermore, the permanent magnets are tangentially magnetized, the magnetization directions of adjacent permanent magnets are consistent, and the magnetization directions of the permanent magnets corresponding to the same position on the first rotor and the second rotor are consistent.

[0010] Furthermore, the armature winding is wound on the stator armature teeth; and the magnetic tuning winding is wound on the stator fault-tolerant teeth.

[0011] Furthermore, the function of the third-order arccosine curve of the boundary between the first rotor pole and the second rotor pole close to the air gap side is:

[0012] γ(α)=k(a)δ / [cos(απ / τ p )-cos(3απ / τ p )]

[0013] The arc cosine curve function of the boundary between the stator armature tooth and the stator fault-tolerant tooth close to the air gap side is:

[0014] γ(α)=δ / cos(απ / τ p )

[0015] Where: γ is the air gap length of the motor, k(a) is the air gap correction coefficient, δ is the air gap length under the conventional boundary, α is the pole arc angle of the rotor tooth, τ p is the rotor pole pitch; the slot depth on the stator fault-tolerant tooth is d, and the slot width is w, wherein d ranges from 0.4 to 0.8 mm, and w ranges from 0.3 to 0.7 mm.

[0016] Furthermore, the first rotor pole, the second rotor pole and the stator core are made of laminated silicon steel materials, and the permanent magnets are neodymium iron boron permanent magnets.

[0017] Beneficial effects of the present invention:

[0018] 1. The permanent magnets of the present invention are arranged on the rotor, which improves the torque density and power density, enhances the torque capacity of the motor under overload conditions, and reduces the motor cogging torque;

[0019] 2. The rotor-side boundary of the air gap is in the shape of a third-order arccosine curve, and the stator-side boundary is also in the shape of an arccosine curve. Auxiliary slots are provided on the stator fault-tolerant teeth. This effectively weakens the air gap magnetic field harmonics that generate cogging torque, thereby reducing torque ripple.

[0020] 3. The armature winding adopts concentrated winding to reduce the end length, reduce the winding resistance and motor copper loss, and achieve high power density and high efficiency. The magnetic regulating winding is connected in parallel with the armature winding magnetic circuit to improve the stability of the permanent magnet working point. While achieving continuous adjustment of the magnetic field, it effectively avoids permanent magnet demagnetization and permanent magnet flux short circuit problems.

[0021] 4. The stator is divided into two parts by a magnetic separator, which realizes the decoupling of the two stator magnetic circuits, reduces the saturation of the magnetic circuit, and improves the fault-tolerant operation capability of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 It is a schematic diagram of the rotor structure of the present invention.

[0025] Figure 3 It is a schematic diagram of the stator structure of the present invention.

[0026] Figure 4 It is a schematic diagram of the stator and rotor boundary curve of the present invention.

[0027] Figure 5 This is the permanent magnet flux path diagram when the angle is α1 according to the present invention.

[0028] Figure 6 This is the permanent magnet flux path diagram when the angle is α2 according to the present invention.

[0029] Figure 7 It is a schematic diagram of the magnetization operation principle of the present invention.

[0030] Figure 8 It is a schematic diagram of the magnetic-weakening operation principle of the present invention.

[0031] In the figure: 1. first rotor; 2. first stator; 3. magnetic spacer disk; 4. second stator; 5. second rotor; 1-1. rotor module unit; 1-2. rotor fixing disk; 1-1-1. first rotor pole; 1-1-2. second rotor pole; 1-1-3. permanent magnet; 2-1. stator core; 2-2. armature winding; 2-3. magnetic adjustment winding; 2-1-1. stator armature teeth; 2-1-2. stator fault-tolerant teeth; 2-1-3. stator yoke; 6. permanent magnet flux path when the rotor angle is α1; 7. permanent magnet flux path when the rotor angle is α2; 8. permanent magnet flux path when the motor is magnetized; 9. excitation flux path when the motor is magnetized; 10. permanent magnet flux path when the motor is flux-weakening; 11. excitation flux path when the motor is flux-weakening. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] A hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor, such as Figure 1 As shown, it includes a coaxially mounted first rotor 1, a first stator 2, a spacer disk 3, a second stator 4 and a second rotor 5. The armature winding 2-2 is wound on the stator armature tooth 2-1-1; the magnetic tuning winding 2-3 is wound on the stator fault-tolerant tooth 2-1-2; the first rotor pole 1-1-1, the second rotor pole 1-1-2 and the stator core 2-1 are made of laminated silicon steel material; the permanent magnet 1-1-3 is a neodymium iron boron permanent magnet; the number of the first rotor pole 1-1-1 and the second rotor pole 1-1-2 is 12n±2k; the number of the stator armature tooth 2-1-1 and the stator fault-tolerant tooth 2-1-2 is 12n; the armature winding 2-2 The number of magnetic tuning windings 2-3 is 12n, where k and n are positive integers; the double-air-gap symmetrical structure composed of the double rotors and double stators can balance the axial magnetic pull on both sides, and the use of the magnetic separator 3 realizes the decoupling of the two stator magnetic circuits, reduces the saturation degree of the magnetic circuit, and improves the fault-tolerant operation capability of the motor.

[0035] like Figure 2 As shown, the first rotor 1 and the second rotor 5 include a rotor module unit 1-1 and a rotor fixed disk 1-2; the rotor module unit 1-1 includes a first rotor pole 1-1-1, a second rotor pole 1-1-2 and a permanent magnet 1-1-3; the first rotor pole 1-1-1 and the second rotor pole 1-1-2 have the same structure; the boundary between the first rotor pole 1-1-1 and the second rotor pole 1-1-2 near the air gap side is a third-order arccosine curve; the rotor module units 1-1 are evenly distributed along the circumference outside the rotor fixed disk 1-2; the permanent magnet 1-1-3 is arranged between the first rotor pole 1-1-1 and the second rotor pole 1-1-2; the permanent magnet 1-1-3 is tangentially magnetized, the magnetization directions of adjacent permanent magnets 1-1-3 are consistent, and the magnetization directions of the permanent magnets 1-1-3 corresponding to the same position on the first rotor 1 and the second rotor 5 are consistent.

[0036] like Figure 3 As shown, the first stator 2 and the second stator 4 include a stator core 2-1, an armature winding 2-2 and a magnetic tuning winding 2-3; the stator core 2-1 includes a stator armature tooth 2-1-1, a stator fault-tolerant tooth 2-1-2 and a stator yoke 2-1-3; the boundary of the stator armature tooth 2-1-1 close to the air gap side is an inverse cosine curve; the boundary of the stator fault-tolerant tooth 2-1-2 close to the air gap side is an inverse cosine function and an auxiliary slot is opened in the center; the stator armature teeth 2-1-1 and the stator fault-tolerant teeth 2-1-2 are evenly and alternately distributed along the circumference of the stator yoke 2-1-3.

[0037] like Figure 4 As shown, the function of the third-order arc cosine curve of the boundary between the first rotor pole 1-1-1 and the second rotor pole 1-1-2 close to the air gap side is: γ(α)=k(a)δ / [cos(απ / τ p )-cos(3απ / τ p )]; The arc cosine curve function of the boundary between the stator armature tooth (2-1-1) and the stator fault-tolerant tooth (2-1-2) close to the air gap side is: γ(α)=δ / cos(απ / τ p ), where: γ is the air gap length of the motor, k(a) is the air gap correction coefficient, δ is the air gap length under the conventional boundary, α is the pole arc angle of the rotor tooth, τ p is the rotor pole pitch; the slot depth on the stator fault-tolerant tooth 2-1-2 is d, and the slot width is w, wherein d ranges from 0.4 to 0.8 mm, and w ranges from 0.3 to 0.7 mm.

[0038] The working principle of the above motor is: when the first rotor 1 and the second rotor 5 run to the angle α1, the permanent magnet flux path 6 is at the rotor angle α1. Figure 5 In the figure, taking phase A as an example, according to the "minimum magnetic resistance principle", the permanent magnetic flux penetrates the armature windings A1 and A2 along the direction of the arrow; when the first rotor 1 and the second rotor 5 run to the angle α2, the permanent magnetic flux path 7 is at Figure 6 , indicating that the magnetic flux exits the armature winding in the direction of the arrow. In the two positions described above, the permanent magnetic flux of the armature windings A1 and A2 has the same value but opposite polarity. When the first rotor 1 and the second rotor 2 rotate continuously, the permanent magnetic flux of the armature windings A1 and A2 periodically varies between positive and negative amplitudes, correspondingly generating an induced electromotive force with alternating amplitude and phase.

[0039] The number of the first rotor poles 1-1-1 and the second rotor poles 1-1-2 is 12n±2k; the number of the stator armature teeth 2-1-1 and the stator fault-tolerant teeth 2-1-2 is 12n; the number of the armature winding 2-2 and the magnetic tuning winding 2-3 is 12n, where k and n are positive integers.

[0040] When the forward excitation current flows into the magnetic winding 2-3, Figure 7 As shown, the dotted line is the permanent magnet flux path 8 when the motor is magnetized, and the dotted line is the excitation flux path 9 when the motor is magnetized. The two fluxes have the same direction, and the combined flux of the two enhances the air gap magnetic field. The motor operates in the magnetization mode. At the same rotor position, the direction of the excitation current is changed, and a reverse excitation current is introduced into the excitation winding, as shown in FIG. Figure 8 As shown, the dashed line represents the permanent magnet flux path 10 during field-weakening operation, while the dotted line represents the excitation flux path 11. The excitation flux and the permanent magnet flux are in opposite directions, and their combined flux weakens the air gap magnetic field, causing the motor to operate in field-weakening mode. By adjusting the direction and magnitude of the excitation current, the flux linkage generated by the field-tuning winding 2-3 is altered, enabling flexible adjustment of the flux linkage of the armature winding 2-2, allowing the motor to operate within a wide constant-power speed regulation range.

[0041] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0042] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor, characterized in that: It comprises a first rotor (1), a first stator (2), a spacer disk (3), a second stator (4) and a second rotor (5) which are coaxially mounted; An air gap exists between the first rotor (1) and the first stator (2), and an air gap exists between the second rotor (5) and the second stator (4); the structure of the first rotor (1), the first stator (2), the second rotor (5) and the second stator (4) is a salient pole structure; the first rotor (1), the first stator (2) and the second rotor (5) and the second stator (4) are respectively located on both sides of the spacer disk (3) and are symmetrically arranged relative to the spacer disk (3); The first rotor (1) and the second rotor (5) comprise a rotor module unit (1-1) and a rotor fixed disk (1-2); the rotor module unit (1-1) comprises a first rotor pole (1-1-1), a second rotor pole (1-1-2) and a permanent magnet (1-1-3); the first rotor pole (1-1-1) and the second rotor pole (1-1-2) have the same structure; the permanent magnet (1-1-3) is arranged between the first rotor pole (1-1-1) and the second rotor pole (1-1-2); the boundary between the first rotor pole (1-1-1) and the second rotor pole (1-1-2) near the air gap side is a third-order arccosine curve; the rotor module units (1-1) are evenly distributed along the circumference outside the rotor fixed disk (1-2); The first stator (2) and the second stator (4) comprise a stator core (2-1), an armature winding (2-2) and a magnetic tuning winding (2-3); the stator core (2-1) comprises stator armature teeth (2-1-1), stator fault-tolerant teeth (2-1-2) and a stator yoke (2-1-3); the boundary of the stator armature teeth (2-1-1) close to the air gap is an arc cosine curve; the boundary of the stator fault-tolerant teeth (2-1-2) close to the air gap is an arc cosine function and an auxiliary slot is opened in the center; the stator armature teeth (2-1-1) and the stator fault-tolerant teeth (2-1-2) are evenly and alternately distributed along the circumference of the stator yoke (2-1-3); The permanent magnets (1-1-3) are tangentially magnetized, the magnetization directions of adjacent permanent magnets (1-1-3) are consistent, and the magnetization directions of the permanent magnets (1-1-3) corresponding to the same position on the first rotor (1) and the second rotor (5) are consistent; The armature winding (2-2) is wound on the stator armature teeth (2-1-1); the magnetic adjustment winding (2-3) is wound on the stator fault-tolerant teeth (2-1-2); The function of the third-order arccosine curve of the boundary between the first rotor pole (1-1-1) and the second rotor pole (1-1-2) close to the air gap side is: γ(α)=k(a)δ / [cos(απ / τ] p )-cos(3a / t p )] The arccosine curve function of the boundary between the stator armature tooth (2-1-1) and the stator fault-tolerant tooth (2-1-2) close to the air gap side is: γ(α)=δ / cos(α / τ) p ) Where: γ is the air gap length of the motor, k(a) is the air gap correction coefficient, δ is the air gap length under the conventional boundary, α is the pole arc angle of the rotor tooth, τ p is the rotor pole pitch; the slot depth on the stator fault-tolerant tooth (2-1-2) is d, and the slot width is w, wherein d ranges from 0.4 to 0.8 mm, and w ranges from 0.3 to 0.7 mm.

2. The hybrid excitation axial magnetic field asymmetric air gap hybrid excitation spoke type permanent magnet motor according to claim 1, characterized in that: The first rotor pole (1-1-1), the second rotor pole (1-1-2), and the stator core (2-1) are made of laminated silicon steel materials, and the permanent magnet (1-1-3) is a neodymium iron boron permanent magnet.

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