Permanent-magnetic vernier electromagnetic drive motor based on semi-embedded special-shaped magnetic poles

Abstract

The application relates to the technical field of permanent magnet synchronous motors, in particular to a permanent magnet vernier electromagnetic drive motor based on a semi-embedded special-shaped magnetic pole, which comprises a stator and a rotor back iron which is a cylindrical barrel and has a plurality of rotor grooves for mounting permanent magnets arranged on the outer side wall; a permanent magnet is arranged in a single rotor groove and comprises a first magnetic part close to the rotor groove and a second magnetic part away from the rotor groove, and is used for generating a magnetic field, wherein the second magnetic part is in a sine configuration. Through the design of the sine-shaped magnetic pole configuration at the bottom, the profile of the semi-embedded permanent magnet at the bottom is changed, the cogging torque is specifically inhibited, the semi-embedded parallel magnetization magnetic pole and the bottom arc harmonic injection technology are combined, the equivalent air gap length is reduced, the air gap magnetic field fundamental wave is enhanced, compared with the traditional uniform pole configuration, the utilization efficiency of the permanent magnet is effectively improved, and the magnetic field energy conversion efficiency is significantly improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of permanent magnet synchronous motors, and particularly relates to a permanent magnet vernier electromagnetic drive motor based on a semi-embedded special-shaped magnetic pole. BACKGROUND

[0002] A permanent magnet vernier motor (PMVM) is a new type of permanent magnet motor, which belongs to the category of flux modulation motors. Compared with a traditional permanent magnet synchronous motor, the permanent magnet vernier motor can realize higher torque density by using the magnetic gear deceleration effect, exhibits better low-speed performance, and is very suitable for direct drive or quasi-direct drive application occasions, such as electric vehicles, aerospace and other fields. A key design factor affecting the output performance of the permanent magnet vernier motor is the magnetic pole shape, which directly affects the air gap magnetic field modulation, torque generation and suppression of cogging torque. Typical magnetic pole configurations of the PMVM include surface-mounted radial / parallel magnetized tile-shaped magnetic poles, combined magnetized Halbach magnetic pole arrays, embedded tangential magnetized spoke-type magnetic pole arrays and the like. However, due to the large number of rotor pole pairs, the inter-pole leakage of the traditional permanent magnet vernier motor is quite serious, resulting in low utilization efficiency of the permanent magnet. In order to improve the utilization efficiency of the permanent magnet of the PMVM, a typical technical solution is to use a consistent pole (CP) rotor configuration, such as a T-type CP, a Halbach-type CP, a spoke-type CP and the like. The consistent pole configuration directly uses an iron pole to replace half of the permanent magnet, and significantly improves the utilization efficiency of the permanent magnet through the magnetic aggregation effect of the iron pole. However, such a magnetic pole configuration will cause the air gap magnetic field of the PMVM to be close to a square wave, thereby introducing a large number of high-order harmonics, resulting in significant cogging torque and torque fluctuation, and increasing the stator leakage inductance, thereby reducing the power factor of the motor.

[0003] Chinese patent application publication No. CN118337015A discloses a new type of shaft radial multi-edge excitation permanent magnet direct drive motor, relating to the field of permanent magnet motors. The motor designed by the invention is a high torque density permanent magnet synchronous motor, which includes a middle stator, an axial rotor, a radial rotor, a support shaft and a bearing. The stator is coaxially located inside the radial rotor and includes a stator core and an armature winding. The radial rotor adopts an outer rotor structure and includes a rotor core and a rotor permanent magnet. The rotor adopts an alternating pole form to install the permanent magnet. An axial rotor is arranged on the left and right sides along the axial direction, which is coaxially and parallelly arranged with the stator, and there is an air gap between the two. There is also an air gap between the stator and the radial rotor. The support shaft plays a role in supporting and fixing the stator. Bearings are added between the support shaft and the axial rotor to realize the rotation of the axial rotor while the support shaft is stationary. The axial rotor and the radial rotor are connected through a mechanical structure made of non-magnetic material to realize the superposition of rotor output. The armature winding wound on the stator adopts a ring winding form to realize the simultaneous linkage with radial and axial magnetic fields using a set of windings. The invention adopts a combined motor structure combining axial flux and radial flux, which can realize high electromagnetic space utilization efficiency and high torque density of the motor, improve the torque output capacity, and meet the application requirements of low speed and high torque of direct drive motors in the industrial field.

[0004] However, the prior art still has the following problems: In the prior art, the number of rotor pole pairs is too large, resulting in serious inter-pole magnetic leakage of the permanent magnet vernier electromagnetic drive motor, thereby reducing the utilization efficiency of the permanent magnet. SUMMARY

[0005] Therefore, the present application provides a permanent magnet vernier electromagnetic drive motor based on semi-embedded special-shaped magnetic poles to overcome the problem of low utilization efficiency of permanent magnets caused by serious inter-pole magnetic leakage of the permanent magnet vernier electromagnetic drive motor due to too many rotor pole pairs in the prior art.

[0006] To achieve the above purpose, the present application provides a permanent magnet vernier electromagnetic drive motor based on semi-embedded special-shaped magnetic poles, comprising:

[0007] a stator;

[0008] a rotor back iron which is a cylindrical body and has a plurality of rotor slots on the outer side wall for installing permanent magnets;

[0009] a permanent magnet arranged in a single rotor slot, including a first magnetic part arranged close to the rotor slot and protruding from the outer side wall of the rotor back iron, and a second magnetic part embedded with the rotor slot, for generating a magnetic field, wherein the first magnetic part is in tile configuration, and the second magnetic part is in sinusoidal configuration;

[0010] The sinusoidal configuration of the second magnetic part is represented by the following formula,

[0011] ;

[0012] The configuration of the permanent magnet is represented by the following formula,

[0013] ;

[0014] wherein, represents the thickness of the first magnetic part, represents the maximum thickness of the second magnetic part, represents the pole angle of the permanent magnet surface relative to the rotor pole coordinate system, represents the pole pair number of the rotor.

[0015] Further, the second magnetic part and the rotor back iron cooperate to inject a magnetic field fundamental wave into a phase magnetic motive force.

[0016] Further, the thickness of the first magnetic part ranges from 0mm to 2mm.

[0017] Further, the maximum thickness of the second magnetic part ranges from 0mm to 4mm.

[0018] Further, the residual magnetic flux density of the permanent magnet is 1.31T.

[0019] Further, two adjacent permanent magnets are installed in the rotor slot in an alternating pole manner.

[0020] Further, the stator comprises a stator core provided with a plurality of stator slots and a three-phase armature winding installed in the stator slot.

[0021] Further, the rated speed of the permanent magnet vernier electromagnetic drive motor is greater than or equal to 500rpm, and the rated torque is greater than or equal to 3N·m.

[0022] Further, the tooth width of the stator ranges from 2mm to 4mm.

[0023] Further, the air gap length of the stator and the permanent magnet ranges from 0.2mm to 0.6mm.

[0024] Compared with the prior art, the beneficial effects of the present application are that the present application designs a bottom sine-shaped magnetic pole configuration, combines a semi-embedded parallel magnetization magnetic pole and a bottom arc harmonic injection technology, reduces the equivalent air gap length, enhances the air gap magnetic field fundamental wave, effectively improves the utilization efficiency of the permanent magnet, and significantly improves the magnetic field energy conversion efficiency.

[0025] Further, the application adopts the shape of the bottom sine-shaped magnetic pole, and by changing the bottom profile of the semi-embedded permanent magnet, the cogging torque is specifically inhibited, and the torque ripple problem caused by the uneven air gap field distribution of the traditional uniform pole configuration is solved. The air gap magnetic field of the traditional embedded magnetic pole tends to be a square wave, and the non-working harmonic content is rich. In the application, the air gap magnetic field distribution of the semi-embedded special-shaped magnetic pole tends to be a sine wave, and the permanent magnet magnetic motive force distribution can be changed by reasonably adjusting the sine bottom arc. Therefore, the content of the rotor magnetic motive force fundamental wave and the third harmonic wave is significantly improved, and the content of the non-working high-order harmonic wave is weakened, thereby effectively inhibiting the cogging torque and further improving the utilization efficiency of the permanent magnet.

[0026] Further, by the combination design of the bottom sine magnetic pole and the semi-embedded structure, the magnetic energy output efficiency of the permanent magnet is optimized. Compared with the traditional tile-shaped magnetic pole and the uniform pole configuration, the average torque output per unit volume of the permanent magnet of the permanent magnet vernier electromagnetic drive motor is increased by 10.8% and 19.7% respectively, which breaks through the torque output bottleneck of the traditional magnetic pole configuration, thereby further improving the utilization efficiency of the permanent magnet.

[0027] Further, by the harmonic regulation effect of the bottom sine-shaped magnetic pole, the high-order air gap magnetic field harmonic is reduced. The high-order harmonic content of the air gap magnetic field of the semi-embedded magnetic pole configuration is lower than that of the traditional configuration, thereby improving the torque output while effectively inhibiting the torque ripple. Compared with the traditional uniform pole configuration, the torque ripple is reduced by 86.9%, which is significantly better than the single magnetic pole shape optimization scheme, thereby further improving the utilization efficiency of the permanent magnet.

[0028] Further, the application constructs a complete design method of the permanent magnet vernier electromagnetic drive motor based on the sine-shaped magnetic pole configuration, integrates the magnetic pole configuration design, harmonic analysis and torque performance optimization, breaks through the problem that theory and engineering practice are disconnected in the traditional design, and provides a standardized technical path for the research and development of different types of permanent magnet vernier electromagnetic drive motors. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is an explosion view of the permanent magnet vernier electromagnetic drive motor based on the semi-embedded special-shaped magnetic pole of the embodiment of the application;

[0030] Figure 2 It is a structure schematic view of the permanent magnet of the embodiment of the application;

[0031] Figure 3 It is a design schematic view of the sine configuration of the second magnetic part of the embodiment of the application;

[0032] Figure 4 It is a design flowchart of the permanent magnet vernier electromagnetic drive motor based on the semi-embedded special-shaped magnetic pole of the embodiment of the application;

[0033] Figure 5A comparison chart of the no-load air-gap flux harmonic of the motor of the embodiment of the present application and a conventional motor;

[0034] Figure 6 A comparison chart of the no-load back EMF of the motor of the embodiment of the present application and a conventional motor;

[0035] Figure 7 A comparison chart of the no-load back EMF harmonic of the motor of the embodiment of the present application and a conventional motor;

[0036] Figure 8 A comparison chart of the no-load back EMF harmonic of the motor of the embodiment of the present application and a conventional motor;

[0037] Figure 9 A comparison chart of the no-load back EMF harmonic of the motor of the embodiment of the present application and a conventional motor;

[0038] In the figure: 1, stator core, 2, three-phase armature winding, 3, permanent magnet, 4, rotor back iron, 5, stator slot, 6, stator tooth, 7, rotor slot, 8, first magnetic part, 9, second magnetic part. DETAILED DESCRIPTION

[0039] In order to make the purpose and advantages of the present application more clear and understandable, the present application is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present application and do not limit the present application.

[0040] The preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0041] It should be noted that, in the description of the present application, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings, which is merely for the convenience of description and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0042] In addition, it should also be noted that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0043] Please refer to Figure 1 and Figure 2As shown, Figure 1 It is an explosion view of a permanent magnet vernier electromagnetic drive motor based on semi-embedded special-shaped magnetic poles according to an embodiment of the application. Figure 2 It is a structural schematic view of a bottom sinusoidal magnetic pole rotor.

[0044] The permanent magnet vernier electromagnetic drive motor based on semi-embedded special-shaped magnetic poles according to an embodiment of the application comprises:

[0045] A stator comprising a stator core 1 provided with a plurality of stator slots 5, and three-phase armature windings 2 installed in the stator slots 5.

[0046] A rotor back iron 4 which is a cylindrical barrel and has a plurality of rotor slots 7 opened around the outer sidewall for installing permanent magnets 3;

[0047] Permanent magnets 3 which are arranged in a single rotor slot 7 and comprise a first magnetic part 8 close to the rotor slot 7 and a second magnetic part 9 away from the rotor slot 7 for generating a magnetic field, wherein the second magnetic part 9 is in a sinusoidal configuration.

[0048] Specifically, the rotor back iron 4 and the plurality of permanent magnets 3 constitute a bottom sinusoidal magnetic pole rotor.

[0049] Please refer to Figure 3 As shown, it is a design schematic view of the sinusoidal configuration of the second magnetic part according to an embodiment of the application.

[0050] Specifically, the sinusoidal configuration of the second magnetic part 9 is represented by the following formula,

[0051] ;

[0052] Then the configuration of the permanent magnet is represented by the following formula,

[0053] ;

[0054] Wherein, represents the thickness of the first magnetic part 8, represents the maximum thickness of the second magnetic part 9, represents the polar angle of the surface of the permanent magnet 3 relative to the rotor polar coordinate system, represents the rotor pole pair number.

[0055] Specifically, the rotor polar coordinate system refers to a polar coordinate system with the two-dimensional projection of the rotor rotation axis as the origin and any one of the N-S poles of the permanent magnet 3 as the polar axis.

[0056] Specifically, the first magnetic part 8 is in a tile configuration and is arranged relative to the outer sidewall of the rotor back iron 4.

[0057] Specifically, the second magnetic part 9 is embedded with the rotor slot 7.

[0058] Specifically, the second magnetic part 9 and the rotor back iron 4 cooperate to inject a magnetic field fundamental wave into a phase magnetic motive force.

[0059] Specifically, the thickness of the first magnetic part 8 ranges from 0mm to 2mm.

[0060] Specifically, the maximum thickness of the second magnetic part 9 ranges from 0mm to 4mm.

[0061] Specifically, the residual magnetic flux density of the permanent magnet is 1.31T.

[0062] Specifically, two adjacent permanent magnets 3 are installed in the rotor slot 7 in an alternating pole manner.

[0063] Specifically, the rated speed of the permanent magnet vernier electromagnetic drive motor is greater than or equal to 500rpm, and the rated torque is greater than or equal to 3N·m.

[0064] Specifically, the tooth width of the stator ranges from 2mm to 4mm.

[0065] Specifically, the air gap length of the stator and the permanent magnet ranges from 0.2mm to 0.6mm.

[0066] Please refer to Figure 4 The figure is a design flowchart of the permanent magnet vernier electromagnetic drive motor based on the semi-embedded special-shaped magnetic pole of the embodiment of the application.

[0067] The design method of the permanent magnet vernier electromagnetic drive motor based on the semi-embedded special-shaped magnetic pole of the embodiment of the application comprises:

[0068] Step S1, permanent magnet vernier electromagnetic drive motor design initialization, determine the motor design target, specifically including: motor rated speed, rated torque, no-load speed, peak torque, etc. The specific target of the design process proposed in the application is to maximize the electromagnetic torque-permanent magnet volume ratio, while minimizing the torque ripple. The main constraint conditions include: bus voltage, phase current, maximum magnetic flux density in the stator tooth 6 / yoke, maximum current density of the winding and all design parameter constraint conditions to avoid structural interference. The design parameters / variables involved include: stator slot number, rotor pole pair number, effective axial length of stator and rotor, stator outer diameter, stator split ratio, stator tooth width, stator slot width, stator yoke thickness, single-phase winding turns, air gap length, rotor magnetic pole arc coefficient, embedded magnetic pole related parameters, embedded magnetic pole related parameters including the thickness of the first magnetic part 8 and the maximum thickness of the second magnetic part 9 .

[0069] Step S2, determine the number of stator slots and the number of rotor pole pairs to meet the target of maximum speed, combined with the limitation of magnetic flux density in the stator, based on the basic principle of slot-pole matching of permanent magnet vernier electromagnetic drive motor, using numerical simulation tools to determine the number of motor stator slots, the number of rotor pole pairs, the corresponding stator structure parameters under the number of slots and the initial structure parameters of the rotor through the method of iterative loop. Higher slot-pole number matching helps to improve torque output, but will result in higher magnetic field change frequency and magnetic flux density in the stator teeth 6, thereby generating higher iron loss, while the slot-pole number matching is also limited by the maximum stator outer diameter and rotor radius.

[0070] Step S3, bottom sine magnetic pole rotor structure parameter optimization, based on numerical simulation tools, calculate the electromagnetic output torque of the motor, the utilization efficiency of the permanent magnet 3 (the ratio of electromagnetic torque to permanent magnet volume), the cogging torque and the torque ripple. The goal of bottom sine magnetic pole rotor structure parameter optimization is to maximize the utilization efficiency of the permanent magnet 3, minimize the cogging torque and torque ripple, the involved optimization variables include the thickness of the first magnetic part 8 , the maximum thickness of the second magnetic part 9 and the permanent magnet pole arc coefficient, and the optimization method used is the multi-parameter scanning method.

[0071] Specifically, the numerical simulation tool used is, for example, ANSYS Maxwell, which is not limited in particular, as long as it meets the simulation requirements. Embodiment 1

[0072] 1. Motor design indicators and constraint conditions

[0073] Motor design indicators: rated speed: ≥500 rpm, rated torque: ≥3.0 N·m, peak torque: ≥6 N·m, cogging torque: ≤50 mN·m, torque ripple: ≤2.0%.

[0074] Design constraint conditions: DC bus voltage: 24 Vdc, stator outer diameter: ≤85 mm, stator effective axial length: ≤30 mm, winding rated current density: ≤7 A / mm 2 , permanent magnet 3 residual flux density: 1.31 T, maximum magnetic flux density in stator teeth 6 / yoke: ≤2.0 T.

[0075] Design parameters / variables: number of stator slots, number of rotor pole pairs, stator effective axial length, stator split ratio, stator tooth width (2-4 mm), stator slot opening coefficient (0.3-0.7), stator yoke thickness (2-4 mm), single-phase winding turns, air gap length (0.2-0.6 mm), rotor magnetic pole arc coefficient (0.7-1), BSPP magnetic pole related parameters: (0-2 mm) and (0-4 mm).

[0076] 2. Motor slot pole matching selection

[0077] Permanent magnet vernier motor drive motor based on electromagnetic deceleration principle / magnetic field modulation principle, its armature magnetic field pole pair number , stator modulation tooth number and permanent magnet pole pair number Meet a specific relationship:

[0078] (1)

[0079] When the permanent magnet vernier drive motor stator slot number is , the stator modulation tooth number can be expressed as:

[0080] (2)

[0081] Where: Indicates the number of stator end split teeth. In the implementation, the goal of achieving rated speed ≥500rpm under the condition of limiting bus voltage to 24Vdc is realized, while considering that the maximum stator outer diameter needs to be ≤85mm, in order to minimize torque ripple and reduce stator core tooth width and yoke thickness, the stator slot number , the open slot configuration of the stator end split tooth number is selected. The stator three-phase armature winding 2 magnetic field pole pair number is selected, in order to avoid the difficulty of producing and realizing a single rotor permanent magnet 3 due to its small size, according to formula (2) to determine the rotor pole pair number .

[0082] The rated winding current density is set to 7A / mm 2 , with the goal of maximizing the no-load back electromotive force coefficient and the rated power factor, the stator and rotor structure parameters are obtained through finite element simulation tool optimization iteration as follows: stator effective axial length: 26mm, stator split ratio (stator inner diameter / stator outer diameter): 0.579, stator tooth width: 2.8mm, stator slot opening coefficient: 0.53, stator yoke thickness: 2.8mm, air gap length: 0.3mm, winding number of turns: 16 (winding slot fill rate: 0.42); Rotor initial structure parameters: rotor magnetic pole arc factor: 0.8-1, : 0-0.5mm, : 1.5mm-3.5mm.

[0083] 3. Bottom sine magnetic pole rotor structure parameter optimization

[0084] Based on a finite element electromagnetic simulation tool, the electromagnetic output torque, the permanent magnet 3 utilization ratio (electromagnetic torque-permanent magnet 3 volume ratio), the cogging torque and the torque ripple of the motor are calculated. The target of the rotor structure parameter optimization is to maximize the permanent magnet 3 utilization ratio, minimize the cogging torque and the torque ripple, the variables to be optimized include the thickness of the first magnetic part 8 of the permanent magnet , the maximum thickness of the second magnetic part 9 and the pole arc coefficient of the permanent magnet 3, and the optimization method adopted is the fast elitist multi-objective genetic optimization algorithm (NSGA-II).

[0085] Based on the above, the relevant parameters of the bottom sine magnetic pole rotor are finally determined as follows: the pole arc coefficient of the rotor magnetic pole: 0.88, mm, mm, the area of a single permanent magnet 3: 9.72mm 2 . By adopting the magnetic pole configuration and the corresponding optimization design method proposed in the application, the performance indicators of the finally designed motor are as follows: the rated speed: 500rpm, the rated torque: 3.62N·m (current density 7A / mm 2 ), the torque ripple: 0.62%, the cogging torque: 3mN·m.

[0086] Please refer to Figure 5 , which is a comparison diagram of the no-load air gap flux density harmonics of the motor of the embodiment of the application and the traditional motor.

[0087] As can be seen from the figure, the profiled magnetic pole configuration is significantly superior to the traditional configuration in the suppression effect on high-order harmonics, especially the 3rd and above.

[0088] Please refer to Figure 6 , which is a comparison diagram of the no-load air gap flux density harmonics of the motor of the embodiment of the application and the traditional motor.

[0089] As can be seen from the figure, the waveform of the profiled magnetic pole configuration is closest to the ideal sine curve, is smooth and distortionless, has the highest amplitude and excellent symmetry, indicating that the magnetic field distribution is uniform and the harmonic interference is minimal; the traditional tile-shaped magnetic pole configuration has obvious peak distortion near 270°, reflecting the local magnetic field mutation caused by high-order harmonics; the traditional embedded uniform pole configuration has the lowest amplitude and flat waveform, and the magnetic field utilization rate is insufficient. In summary, the profiled magnetic pole configuration is superior to the traditional configuration in the no-load back electromotive force amplitude, the waveform sinusoidal degree and the stability, and is more conducive to reducing the motor torque ripple and noise.

[0090] Please refer to Figure 7 , which is a comparison diagram of the no-load back electromotive force harmonics of the motor of the embodiment of the application and the traditional motor.

[0091] As can be seen from the figure, the heteromorphic magnetic pole configuration has the highest fundamental voltage (1st order) and almost completely eliminates high-order harmonics (3rd order and above) (6 / 8 order approaches 0), and has the best waveform purity; the traditional tile-shaped magnetic pole configuration has the second highest fundamental voltage, but has a significant 3rd order harmonic peak (about 60% of the fundamental) and residual 6 / 8 order interference; the traditional embedded uniform pole configuration has the lowest fundamental voltage and relatively high 3 / 4 order harmonic amplitude. In summary, the heteromorphic magnetic pole configuration is superior to the traditional design in both voltage output capability and harmonic suppression, and can greatly reduce motor electromagnetic noise and iron loss.

[0092] Referring to Figure 8 Fig. 3 is a comparison diagram of the torque of the motor of the embodiment of the present application and a traditional motor.

[0093] As can be seen from the figure, the heteromorphic magnetic pole configuration simultaneously achieves the highest average torque (3.62 N·m) and the lowest torque ripple (0.62%), and has stable output and optimal efficiency; the traditional tile-shaped magnetic pole configuration has the second highest average torque (3.24 N·m) and slightly higher ripple (0.65%), and has slight fluctuations; the traditional uniform pole configuration has the lowest average torque (3.00 N·m) and severe ripple (10.73%), and has poor stability. In summary, the heteromorphic magnetic pole configuration is significantly superior in torque output capability and running stability.

[0094] Referring to Figure 9 Fig. 4 is a comparison diagram of the torque-phase current characteristics of the motor of the embodiment of the present application and a traditional motor.

[0095] As can be seen from the figure, the heteromorphic magnetic pole configuration has the most uniform phase current density distribution, no local overheating point, and the highest average torque; the traditional tile-shaped magnetic pole configuration has a slight concentration of current density, and the average torque is second; the traditional embedded uniform pole configuration has uneven current density distribution, and has a significant local high-density area, and the average torque is the lowest. In summary, the heteromorphic magnetic pole configuration simultaneously improves the current distribution uniformity and torque output capability by optimizing the magnetic field topology, and greatly reduces the risk of thermal runaway and torque fluctuation.

[0096] Specifically, the traditional motor is a permanent magnet vernier motor using a traditional magnetic pole configuration, and the traditional magnetic pole configuration includes a traditional tile-shaped magnetic pole configuration and a traditional embedded uniform pole magnetic pole configuration.

[0097] Thus, the technical solutions of the present application have been described in connection with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after these changes or replacements will all fall within the protection scope of the present application.

Claims

1. A permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles, comprising a stator, characterized in that, Also includes: The rotor back iron is a cylindrical body with several rotor slots around its outer wall for mounting permanent magnets. A permanent magnet, disposed within a single rotor slot, includes a first magnetic part disposed near the outer wall of the rotor slot and protruding relative to the rotor back iron, and a second magnetic part fitted into the rotor slot, for generating a magnetic field, wherein the first magnetic part is in a tile configuration and the second magnetic part is in a sinusoidal configuration; The sinusoidal configuration of the second magnetic part is expressed by the following formula. ， The configuration of the permanent magnet is then expressed by the following formula. ， in, This indicates the thickness of the first magnetic part. This indicates the maximum thickness of the second magnetic part. This represents the polar angle of the permanent magnet surface relative to the rotor's polar coordinate system. Indicates the number of rotor pole pairs; The rotor back iron and several permanent magnets form a bottom sinusoidal magnetic pole rotor.

2. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 1, characterized in that, The second magnetic part and the rotor back iron work together to inject the fundamental magnetic field wave into the phase magnetomotive force.

3. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 2, characterized in that, The thickness of the first magnetic part ranges from 0 mm to 2 mm.

4. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 3, characterized in that, The maximum thickness of the second magnetic part ranges from 0 mm to 4 mm.

5. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 4, characterized in that, The residual magnetic flux density of the permanent magnet is 1.31T.

6. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 1, characterized in that, The two adjacent permanent magnets are installed in the rotor slots with alternating poles.

7. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 1, characterized in that, The stator includes a stator core with several stator slots and a three-phase armature winding installed in the stator slots.

8. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 1, characterized in that, The rated speed of the permanent magnet vernier electromagnetic drive motor is greater than or equal to 500 rpm, and the rated torque is greater than or equal to 3 N·m.

9. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 1, characterized in that, The tooth width of the stator ranges from 2mm to 4mm.

10. The permanent magnet vernier electromagnetic drive motor based on semi-embedded irregular magnetic poles according to claim 1, characterized in that, The air gap length between the stator and the permanent magnet ranges from 0.2 mm to 0.6 mm.

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