A bipolar axial magnetic modulation permanent magnet synchronous motor and its driving method

Abstract

The present invention discloses a bipolar axial magnetic modulation permanent magnet synchronous motor and a driving method thereof, comprising: a stator, a first rotor, a second rotor and an annular magnetic flux closing sleeve; the first rotor and the second rotor are coaxially connected, and an annular magnetic flux closing sleeve is provided at both ends, and an excitation winding is provided in the annular magnetic flux closing sleeve; the first rotor is provided with a first rib structure, the first rib structure is connected to an inner ring magnetic conductive spoke, the second rotor is provided with a second rib structure, the second rib structure is connected to an outer ring magnetic conductive spoke, the inner ring magnetic conductive spoke and the outer ring magnetic conductive spoke are both extended to be connected to the annular magnetic flux closing sleeve at both ends of the two rotor sections; the first rib structure and the second rib structure are staggered at an angle in the axial direction, the polarities of the two rotor sections are opposite, the magnetic flux on each rotor section enters the other rotor section along the rib structure, the magnetic conductive spoke and the annular magnetic flux closing sleeve to form a closed magnetic circuit, the magnetic flux of the closed magnetic circuit is adjusted by the excitation winding, and the magnetic flux adjustment is flexibly achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motors, and in particular to a bipolar axial magnetization permanent magnet synchronous motor and a driving method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Permanent magnet motors are widely used as core components in equipment such as electric vehicles, aircraft and ships, and high-speed cutting systems due to their advantages such as high speed, high efficiency, and high power density. However, permanent magnet motors have defects in flux regulation due to the use of permanent magnets with fixed magnetomotive force. Traditional permanent magnet motors often use a control strategy of applying a demagnetization current to the motor's direct axis to achieve air gap magnetic field regulation. Although this method can compensate for the shortcomings of permanent magnet motors to a certain extent, it cannot fundamentally solve the problem. In addition, incorrect and excessive direct axis demagnetization control of permanent magnet motors will cause the following problems:

[0004] (1) Large demagnetization currents can easily lead to irreversible demagnetization of permanent magnets, which can reduce motor efficiency and even cause danger.

[0005] (2) With the addition of demagnetization current, the copper loss of the motor winding, the iron loss of the motor core, and the switching loss of the control circuit will increase, causing the efficiency of the entire system, especially in the high-speed operation area, to decrease;

[0006] (3) Considering the direct-axis demagnetization current during the design phase will increase the inverter capacity, bus voltage level, and the selection of the motor's own line type, thereby increasing the cost of the motor system;

[0007] (4) When the control circuit and inverter capacity are constant, the existence of direct-axis current will lead to a decrease in the quadrature-axis current content, limiting the constant power operating range of the motor;

[0008] (5) There is a risk of failure in weak magnetic control, especially when the system is in high-speed operation. Once weak magnetic failure occurs, it will cause serious hazards such as damage to power devices.

[0009] Unlike permanent magnet motors, the magnetic field of an electrically excited motor is established solely by the excitation current. During actual operation, the motor's magnetic field can be freely controlled by the excitation current. However, due to the presence of the field winding, electrically excited motors inevitably suffer from lower efficiency and power density. To combine the advantages of both permanent magnet and electrically excited motors while minimizing their disadvantages, the concept of "hybrid excitation" emerged in 1988. Inspired by this concept, numerous researchers have proposed a variety of ingenious hybrid excitation motor structures and unique control algorithms adapted to them. With the gradual deepening of research and the recent development of rare earth resources, high-performance hybrid excitation motors have flourished in fields such as renewable energy power generation, transportation, and national defense and military.

[0010] In hybrid excitation synchronous motors, the ability of the electric excitation to regulate the motor's main pole flux is an important technical indicator. The electric excitation winding should have good regulation capability and a large regulation ratio on the motor's main pole flux while being small in size and highly integrated.

[0011] However, traditional permanent magnet motors and general hybrid excitation motors have only one set of excitation ports. When used for power generation or motor operation, they can only output / input power on a single line and at a single voltage level. However, the drive / distribution systems in various large drive systems today often have multiple lines and multiple voltage levels. Single-port hybrid excitation cannot support this multi-magnetic circuit coordinated regulation method, and the single-port hybrid excitation flux regulation capability is generally limited, which cannot meet the current large-scale, complex, and multi-circuit coordinated industrial applications. Summary of the Invention

[0012] In order to solve the above problems, the present invention proposes a bipolar axial magnetic modulation permanent magnet synchronous motor and a driving method thereof. The magnetic flux on each rotor section enters the other rotor section along the rib structure, magnetic spokes, and annular magnetic flux closing sleeve to form a closed magnetic circuit. At the same time, the magnetic flux of the closed magnetic circuit is adjusted by the current of the excitation winding, thereby indirectly controlling the magnetic flux of each pole of the rotor and flexibly realizing magnetic flux regulation.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions:

[0014] In a first aspect, the present invention provides a bipolar axial magnetic modulation permanent magnet synchronous motor, comprising: a stator, a first rotor, a second rotor and an annular magnetic flux closing sleeve;

[0015] The first rotor and the second rotor are both built into the stator, one end of the first rotor is provided with a circular flux closing sleeve, the other end of the first rotor is coaxially connected to the second rotor, and then a circular flux closing sleeve is provided on the other end of the second rotor, and the circular flux closing sleeves are both provided with excitation windings;

[0016] The yoke of the first rotor is provided with a first rib structure, the first rib structure is connected to an inner ring of magnetic conductive spokes, the yoke of the second rotor is provided with a second rib structure, the second rib structure is connected to an outer ring of magnetic conductive spokes, and the inner ring of magnetic conductive spokes and the outer ring of magnetic conductive spokes are both extended to the annular magnetic flux closing sleeves at both ends of the two rotor sections;

[0017] The first rib structure and the second rib structure are staggered in the axial direction and form a staggered angle. The rib structure of each rotor section and the magnetic spokes connected to it have the same polarity, and the polarity between the two rotor sections is opposite. The magnetic flux on each rotor section enters the other rotor section along the rib structure, the magnetic spokes, and the annular magnetic flux closing sleeve to form a closed magnetic circuit, and the magnetic flux of the closed magnetic circuit is adjusted by the current of the excitation winding.

[0018] As an optional embodiment, the outer ring magnetic spokes and the inner ring magnetic spokes have different radii and the same length, and the magnetic flux of the inner ring magnetic spokes and the outer ring magnetic spokes are closed at the ends by a circular magnetic flux closing sleeve.

[0019] As an optional implementation, the staggered angle is 360 / 2p degrees, where p is the number of motor pole pairs.

[0020] As an optional implementation manner, the number of motor pole pairs is greater than or equal to 1.

[0021] As an optional embodiment, the inner and outer rings of the annular magnetic flux closing sleeve correspond to the inner and outer ring magnetic spokes, and there is an air gap between the inner and outer rings of the annular magnetic flux closing sleeve. An excitation winding is arranged in the air gap, and the magnetic flux flowing through the closed magnetic circuit is dynamically adjusted by applying current to the excitation winding.

[0022] As an optional embodiment, the first rotor and the second rotor are both provided with rotor slots, and permanent magnets are provided in the rotor slots. The magnetic flux generated by the permanent magnets forms the main magnetic circuit of the motor and the motor magnetic adjustment circuit, and the main magnetic circuit of the motor and the motor magnetic adjustment circuit are connected in parallel.

[0023] As an optional implementation, when a magnetizing current is applied to the excitation winding, the main magnetic flux of the main magnetic circuit of the motor is increased to achieve magnetizing operation;

[0024] When a weak magnetic current is applied to the excitation winding, the closed magnetic flux of the motor's magnetic regulation circuit is increased, the main magnetic flux is reduced, and weak magnetic operation is achieved.

[0025] As an optional embodiment, the stator is coaxially arranged with the first rotor and the second rotor, and an air gap is provided between the stator and the rotor. The magnetic flux generated by the permanent magnet enters the air gap to form the main magnetic circuit of the motor.

[0026] As an optional implementation, the closed magnetic circuit is a motor magnetic regulation circuit.

[0027] In a second aspect, the present invention provides a driving method for a bipolar axially-magnetically-adjustable permanent magnet synchronous motor, which is applied to the bipolar axially-magnetically-adjustable permanent magnet synchronous motor described in the first aspect, comprising:

[0028] The motor main magnetic circuit and the motor magnetic adjustment magnetic circuit are operated in parallel. The motor main magnetic circuit is formed by the magnetic flux generated by the permanent magnets entering the air gap between the stator and the rotor to form the motor main magnetic circuit. The motor magnetic adjustment magnetic circuit is a closed magnetic circuit formed by the magnetic flux on each rotor section entering the other rotor section along the rib structure, magnetic spokes, and annular magnetic flux closing sleeve;

[0029] When the motor starts or operates normally, the magnetizing current is applied through the excitation winding according to the torque requirement, which reduces the magnetic flux generated by the permanent magnet in the closed magnetic circuit and increases the magnetic flux in the main magnetic circuit of the motor;

[0030] When the motor is running in weak magnetic field, the current of the excitation winding is reduced, the magnetic flux of the closed magnetic circuit is increased, and the magnetic flux of the main magnetic circuit of the motor is reduced.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention provides a bipolar axially regulated permanent magnet synchronous motor and its drive method. The rotor consists of two rotor sections, each with an interlaced rib structure connected to magnetically conductive spokes on the rotor end shaft. The ribs of the two rotor sections are staggered by 360 / 2p degrees, so that the polarity of the ribs and magnetically conductive spokes of each rotor section is opposite to that of the ribs and magnetically conductive spokes of the other rotor section. The magnetically conductive spokes of the two rotor sections extend beyond the ends of the motor. Circular flux-enclosing sleeves are provided at each end. The magnetic flux from one rotor section can enter the other rotor section along the "rotor ribs-magnetic spokes-circular flux-enclosing sleeve" path, forming a closed loop. Excitation windings are placed in the air gap between the inner and outer rings of the circular flux-enclosing sleeves on both sides of the motor. These windings can apply current to control the amount of magnetic flux passing through the "rotor ribs-magnetic spokes-circular flux-enclosing sleeve" path, thereby indirectly controlling the magnetic flux per pole of the rotor and achieving flexible flux regulation.

[0033] The magnetic spokes of this invention conduct magnetism along both sides of the motor's axis, and circular flux-enclosing sleeves are installed on both sides of the rotor. This creates two separate magnetic paths for magnetic modulation. The flux generated by the motor's permanent magnets passes through the rotor ribs, increasing the amount of flux generated, thus expanding the magnetic modulation range. The magnetic modulation windings are dispersed on both sides of the motor, with heat dissipation located at the motor end caps, improving heat dissipation performance. Furthermore, the extension of the magnetic spokes to both sides reduces their thickness, contributing to a smaller and more compact motor.

[0034] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 A schematic diagram showing the outer ring of magnetic spokes of the rotor structure provided in Example 1 of the present invention;

[0037] Figure 2 A schematic diagram showing the inner ring of the magnetic spokes of the rotor structure provided in Example 1 of the present invention;

[0038] Figure 3 A schematic diagram of the overall structure of a motor provided in Example 1 of the present invention;

[0039] Among them, 1. first rotor, 2. second rotor, 3. permanent magnet, 4. first rib structure, 5. inner ring magnetic spokes, 6. second rib structure, 7. outer ring magnetic spokes, 8. excitation winding, 9. circular flux closure sleeve, 10. stator, 11. armature winding, 12. stator teeth, 13. stator slots. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0043] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0044] Example 1

[0045] This embodiment provides a bipolar axial magnetic modulation permanent magnet synchronous motor, such as Figure 1-Figure 3As shown, it includes: a stator 10, a first rotor 1, a second rotor 2 and a circular magnetic flux closing sleeve 9;

[0046] Specifically:

[0047] The stator 10 is made of laminated silicon steel sheets and includes stator slots 13, stator teeth 12 and a stator yoke. The armature winding 11 is placed in the stator slots 13.

[0048] As an optional implementation, the armature winding 11 may be a single-layer winding or a double-layer winding.

[0049] As an optional implementation, the armature winding 11 can be divided into a distributed winding, a concentrated winding or a lapped winding.

[0050] As an optional implementation, the number of poles of the armature winding 11 is consistent with the number of rotor poles.

[0051] As an optional embodiment, the stator 10 is coaxially arranged with the first rotor 1 and the second rotor 2, and there is an air gap between the stator and the rotor. A part of the magnetic flux generated by the rotor passes through the outer diameter of the rotor into the air gap to form the main pole magnetic flux of the rotor.

[0052] In this embodiment, the first rotor 1 and the second rotor 2 are coaxially connected and built into the stator; one end of the first rotor 1 is provided with a circular flux closing sleeve 9, the other end of the first rotor 1 is coaxially connected to the second rotor 2, and the other end of the second rotor 2 is also provided with a circular flux closing sleeve 9, and an excitation winding 8 is provided in each of the circular flux closing sleeves 9.

[0053] In this embodiment, the first rotor 1 and the second rotor 2 have the same structure. The yoke of the first rotor 1 is provided with a first rib structure 4, and the yoke of the second rotor 2 is provided with a second rib structure 6. The first rib structure 4 and the second rib structure 6 are staggered in the axial direction and form a staggered angle. The rib structures are respectively connected to the N pole or S pole of the corresponding rotor segment, and the rib structures of the two rotor segments present opposite magnetic polarity.

[0054] As an optional implementation, the stagger angle is related to the number of poles, which is 360 / 2p degrees; taking an 8-pole motor as an example, the stagger angle is 45 degrees.

[0055] In this embodiment, the end of the first rotor 1 is provided with an inner ring of magnetic conductive spokes 5 connected to the first rib structure 4, and the end of the second rotor 2 is provided with an outer ring of magnetic conductive spokes 7 connected to the second rib structure 6 and having a different radius from the inner ring of magnetic conductive spokes 5. Since the rib structures of the two rotor sections have opposite magnetic polarities, the rib structure of each rotor section and the magnetic conductive spokes connected thereto have the same polarity, and the polarity between the two rotor sections is opposite.

[0056] The inner ring magnetic spokes 5 and the outer ring magnetic spokes 7 are extended and connected to the annular magnetic flux closing sleeve 9 at both ends. The magnetic flux of the inner ring magnetic spokes 5 and the outer ring magnetic spokes 7 are closed at the ends through the annular magnetic flux closing sleeve 9, so that the magnetic flux generated by the permanent magnet on each rotor section enters the other rotor section along the "rib structure-magnetic spokes-annular magnetic flux closing sleeve", forming a closed magnetic circuit.

[0057] In this embodiment, the inner and outer rings of the annular magnetic flux closing sleeve 9 correspond to the inner and outer ring magnetic spokes, and there is an air gap between the inner and outer rings of the annular magnetic flux closing sleeve 9. An excitation winding 8 is arranged in the air gap. When the motor is running, the magnetic flux flowing through the closed magnetic circuit is dynamically adjusted by applying current to the excitation winding 8. At the same time, the main magnetic flux during the operation of the motor is also dynamically adjusted, so that the magnetic flux of each pole can be controlled to realize the mixed excitation of the motor.

[0058] As an optional embodiment, the inner ring magnetic spokes 5 and the outer ring magnetic spokes 7 have different radii and the same length, and both extend to both sides of the rotor end, guiding the rib magnetic flux of different polarities of the two sections of the rotor to both sides of the rotor end.

[0059] In this embodiment, each rotor section has eight rotor slots for accommodating permanent magnets 3. The magnetization directions of two adjacent permanent magnets 3 are opposite. The two adjacent permanent magnets 3 and the rotor core between them generate radial magnetic poles in the radial direction. The magnetic flux generated by the permanent magnets 3 passes through the radial magnetic poles, through the stator-rotor air gap, into the stator core, and interlinks with the armature winding to form the main magnetic flux.

[0060] When the motor is running, a current is applied through the excitation winding 8 to reduce the magnetic flux in the closed magnetic circuit branch of the "rib structure-magnetic spokes-annular magnetic flux closing sleeve". At this time, most of the magnetic flux generated by the permanent magnet enters the stator 10 to form the main magnetic flux of the motor, so that the magnetic flux of each pole of the motor is maintained at a high level.

[0061] Alternatively, a weakening current is applied to the excitation winding. At this time, more magnetic flux passes through the closed magnetic circuit, and the magnetic flux passing through the stator and rotor air gap is reduced, thereby reducing the main magnetic flux of the motor, thereby achieving weakening magnetic control, widening the constant power operation area of ​​the motor, and realizing hybrid excitation of the motor.

[0062] As an optional embodiment, the permanent magnets are arranged in series and parallel to achieve a "magnetic concentration effect", forming radial magnetic poles in the radial direction of the rotor. The magnetic flux generated by the permanent magnets can enter the air gap in the radial direction, and the rotor can generate eddy currents when the motor starts, thereby achieving self-starting.

[0063] The magnetic flux generated by the permanent magnet forms two magnetic circuits through the "magnetic focusing effect". The first magnetic circuit includes the stator and rotor air gap and the stator, which is the main magnetic circuit of the motor. The other magnetic circuit includes the rotor ribs, rotor magnetic spokes and an annular magnetic flux closing sleeve, which is the motor magnetic adjustment circuit. The two magnetic circuit branches are in parallel.

[0064] As an optional embodiment, the first rotor and the second rotor can be made of laminated silicon steel sheets, or made of soft magnetic composite materials with high magnetic permeability, or made of a mixture of silicon steel sheets and soft magnetic composite materials.

[0065] As an optional implementation manner, the first rotor and the second rotor are both solid rotors, and the solid rotor has high magnetic permeability.

[0066] As an optional embodiment, the permanent magnet can be a high-performance permanent magnet material, such as neodymium iron boron, rare earth cobalt, etc., or a low-coercivity permanent magnet material, such as aluminum nickel cobalt or ferrite, etc.

[0067] As an optional implementation manner, the number of phases m of the motor is ≥3, and the number of pole pairs p of the motor is ≥1.

[0068] In this embodiment, the magnetic flux generated by the permanent magnet is divided into two parts. One part passes through the outer diameter of the rotor and enters the stator-rotor air gap to form the main pole magnetic flux. The stator armature winding is fed with three-phase AC current to generate a rotating magnetic field, which interacts with this part of the magnetic field to generate torque.

[0069] The other part forms a closed magnetic circuit through the staggered rib structure and the inner and outer ring magnetic spokes design, and does not participate in energy conversion;

[0070] The inner and outer rings of the annular flux closure sleeve have different polarities, and an excitation winding is set in the air gap between the inner and outer rings. By changing the current size and direction of the excitation winding, the size of the magnetic flux generated by the permanent magnet passing through the staggered rib structure can be controlled, thereby controlling the magnetic flux of each pole of the motor and realizing hybrid excitation of the motor.

[0071] Specifically, when the motor is starting or running under heavy load, a magnetizing current is applied through the excitation winding to further "magnetize" each magnetic pole of the motor, increasing the main magnetic flux of each pole of the motor during the starting process, improving the motor's starting ability and increasing the motor's torque output capacity;

[0072] When the motor is running at high speed, the magnetizing current on the excitation winding is reduced or a reverse weakening current is applied to increase the flow of permanent magnet flux in the motor's "rib structure-magnetic spokes-circular flux closed sleeve", thereby reducing the motor's main magnetic flux flowing through the stator and rotor air gap, achieving weakening speed expansion, and effectively expanding the motor's constant power operating range.

[0073] In this embodiment, the excitation winding is a stationary winding. When the motor is operating normally, the excitation winding may not be applied with current, or a magnetizing current may be applied. When the excitation winding is applied with a magnetizing current, the main magnetic flux of the motor increases, realizing magnetizing operation. When the excitation winding is applied with a weak magnetic current, the main magnetic flux of the motor decreases, realizing weak magnetic operation.

[0074] In this embodiment, various performances are achieved by reasonably designing various parameters of the motor, such as the air gap length, the number of turns of the stator armature winding, and the number of turns of the rotor built-in current winding, based on the rated speed, rated torque, and specific performance requirements of the motor. For example, the number of motor phases is designed to be 3, the number of stator teeth is designed to be 48, the number of rotor slots is designed to be 8, the two-section rotor has a total of 8 ribs, the number of permanent magnet blocks is designed to be 16, and the number of rotor poles is designed to be 8.

[0075] In this embodiment, the rotor end of the motor of this embodiment can be provided with an excitation winding capable of applying current between the inner and outer air gaps of the annular flux-closing sleeve. By controlling the magnitude and direction of the current applied to the excitation winding, the magnitude of the motor's main magnetic flux can be controlled. Through reasonable design, the excitation winding can be de-energized when the motor is operating under rated conditions, significantly reducing excitation losses at the motor's rated operating point and helping to improve the motor's operating efficiency. Furthermore, the annular flux-closing sleeve and its excitation winding can be designed as mechanically movable elements. When the motor is operating normally and does not require field weakening or field boosting, the mechanically movable device can be used to disconnect the closed magnetic circuit, further increasing the motor's main magnetic flux and improving its force energy density and power output.

[0076] Example 2

[0077] This embodiment provides a torque drive method for a bipolar axially-magnetically modulated permanent magnet synchronous motor as described in Example 1. Current applied to the stator armature winding interacts with the rotor's main magnetic field to generate a driving torque. The excitation winding between the annular flux-enclosing sleeve at the motor end achieves hybrid excitation by regulating the magnetic flux of the "rotor rib-magnetic spoke-annular flux-enclosing sleeve" branch. Specifically, the method includes:

[0078] When the motor is starting or operating normally, the excitation winding between the annular flux closure sleeves can apply magnetizing currents of different amplitudes according to the torque requirements, reducing the flow of the magnetic flux generated by the permanent magnets in the staggered rib structure of the rotor yoke, so that the main magnetic flux per pole in the radial direction of the motor reaches a higher value;

[0079] When the motor needs to perform field weakening operation, the excitation winding current between the annular flux closure sleeves is reduced, so that more of the magnetic flux generated by the permanent magnets passes through the "rotor ribs-magnetic spokes-annular flux closure sleeve" structure, thereby reducing the radial main magnetic flux of the motor and playing the role of field weakening and speed expansion;

[0080] At the same time, the motor can operate without applying excitation winding current. At this time, part of the magnetic flux generated by the permanent magnet passes through the "rotor ribs-magnetic spokes-circular magnetic flux closing sleeve" to form a closed magnetic circuit, and part of it constitutes the main magnetic flux of the motor. The operation mode at this time is the same as that of an ordinary motor.

[0081] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A bipolar axial magnetic modulation permanent magnet synchronous motor, characterized in that: include: a stator, a first rotor, a second rotor and an annular flux closing sleeve; The first rotor and the second rotor are both built into the stator, one end of the first rotor is provided with a circular flux closing sleeve, the other end of the first rotor is coaxially connected to the second rotor, and then a circular flux closing sleeve is provided on the other end of the second rotor, and the circular flux closing sleeves are both provided with excitation windings; The yoke of the first rotor is provided with a first rib structure, the first rib structure is connected to an inner ring of magnetic conductive spokes, the yoke of the second rotor is provided with a second rib structure, the second rib structure is connected to an outer ring of magnetic conductive spokes, and the inner ring of magnetic conductive spokes and the outer ring of magnetic conductive spokes are both extended to the annular magnetic flux closing sleeves at both ends of the two rotor sections; The first rib structure and the second rib structure are staggered in the axial direction and have a staggered angle. The rib structure of each rotor section and the magnetic spokes connected thereto have the same polarity, while the polarity between the two rotor sections is opposite. The magnetic flux on each rotor section enters the other rotor section along the rib structure, the magnetic spokes, and the annular magnetic flux closing sleeve, forming a closed magnetic circuit. The magnetic flux of the closed magnetic circuit is adjusted by the current of the excitation winding. The outer ring magnetic spokes and the inner ring magnetic spokes have different radii but the same length, and the magnetic fluxes of the inner ring magnetic spokes and the outer ring magnetic spokes are closed at the ends by a circular magnetic flux closing sleeve; The first rotor and the second rotor are both provided with rotor slots, and permanent magnets are provided in the rotor slots. The magnetic flux generated by the permanent magnets forms a main magnetic circuit of the motor and a magnetic circuit of the motor, and the main magnetic circuit of the motor and the magnetic circuit of the motor are connected in parallel; The stator is coaxially arranged with the first rotor and the second rotor, and an air gap is provided between the stator and the rotor. The magnetic flux generated by the permanent magnet enters the air gap to form the main magnetic circuit of the motor.

2. A bipolar axial magnetic modulation permanent magnet synchronous motor according to claim 1, characterized in that: The staggered angle is 360 / 2p degrees, where p is the number of motor pole pairs.

3. A bipolar axial magnetic modulation permanent magnet synchronous motor according to claim 2, characterized in that: The number of motor pole pairs is greater than or equal to 1.

4. A bipolar axial magnetic modulation permanent magnet synchronous motor according to claim 1, characterized in that: The inner and outer rings of the annular magnetic flux closing sleeve correspond to the inner and outer magnetic spokes. There is an air gap between the inner and outer rings of the annular magnetic flux closing sleeve. An excitation winding is arranged in the air gap. The magnetic flux flowing through the closed magnetic circuit is dynamically adjusted by applying current to the excitation winding.

5. The bipolar axial magnetic modulation permanent magnet synchronous motor according to claim 1, characterized in that: When the magnetizing current is applied to the excitation winding, the main magnetic flux of the motor's main magnetic circuit is increased, achieving magnetizing operation; When a weak magnetic current is applied to the excitation winding, the closed magnetic flux of the motor's magnetic regulation circuit is increased, the main magnetic flux is reduced, and weak magnetic operation is achieved.

6. The bipolar axial magnetic modulation permanent magnet synchronous motor according to claim 1, characterized in that: The closed magnetic circuit is a motor magnetic regulation circuit.

7. A driving method for a bipolar axial magnetic modulation permanent magnet synchronous motor, characterized in that: The bipolar axial magnetic modulation permanent magnet synchronous motor according to any one of claims 1 to 6 comprises: The motor main magnetic circuit and the motor magnetic adjustment magnetic circuit are operated in parallel. The motor main magnetic circuit is formed by the magnetic flux generated by the permanent magnets entering the air gap between the stator and the rotor to form the motor main magnetic circuit. The motor magnetic adjustment magnetic circuit is a closed magnetic circuit formed by the magnetic flux on each rotor section entering the other rotor section along the rib structure, magnetic spokes, and annular magnetic flux closing sleeve; When the motor starts or operates normally, the magnetizing current is applied through the excitation winding according to the torque requirement, which reduces the magnetic flux generated by the permanent magnet in the closed magnetic circuit and increases the magnetic flux in the main magnetic circuit of the motor; When the motor is running in weak magnetic field, the current of the excitation winding is reduced, the magnetic flux of the closed magnetic circuit is increased, and the magnetic flux of the main magnetic circuit of the motor is reduced.

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