Axial double-sided magnetization permanent magnet synchronous motor and control method thereof

Abstract

The present invention discloses an axial double-sided magnetized permanent magnet synchronous motor and a control method thereof, comprising: a rotor, end annular sleeves are provided at both ends of the rotor, annular permanent magnets are provided in the end annular sleeves; the rotor comprises a first section rotor and a second section rotor, the first section rotor is provided with a first rib structure and an inner ring magnetic conductive spoke connected to the first rib structure, the second section rotor is provided with a second rib structure and an outer ring magnetic conductive spoke connected to the second rib structure, the inner ring magnetic conductive spokes and the outer ring magnetic conductive spokes extend to the end annular sleeve; the inner and outer walls of the end annular sleeve correspond to the inner and outer ring magnetic conductive spokes respectively, the magnetic flux generated by the annular permanent magnet on the end annular sleeve enters the stator-rotor air gap through the end annular sleeve, the inner and outer ring magnetic conductive spokes and the rib structure to magnetize the main magnetic flux of the motor, and the magnetic flux is changed by adjusting the air gap length between the end annular sleeve and the inner and outer ring magnetic conductive spokes, thereby realizing the main magnetic flux regulation of the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motors, and in particular to an axial double-sided magnetized permanent magnet synchronous motor and a control 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] Compared with ordinary motors, permanent magnet motors have excellent operating performance in many fields, especially their inherent energy-saving characteristics and almost identical excellent operating characteristics at high and low speeds. As a result, once permanent magnet motors enter a certain application field in recent years, they are favored and promoted in that field.

[0004] According to the inventors' understanding, existing permanent magnet synchronous motors have the following technical disadvantages:

[0005] The permanent magnet of a permanent magnet synchronous motor has a fixed magnetomotive force. The main magnetic flux is determined after the motor is manufactured, and the magnetic flux of each pole of the motor cannot be controlled, resulting in poor starting capability. A higher starting current needs to be applied to obtain the starting torque. In addition, the motor has poor speed regulation capability, a narrow constant power operating range, and an insufficient speed regulation range.

[0006] To address the magnetic field modulation problem of permanent magnet motors, hybrid excitation motors (HEMs), which inherit the advantages of both permanent magnet and electrically excited motors, have been proposed and have achieved considerable development. Through ingenious electromagnetic structural design and a matching control algorithm, hybrid excitation permanent magnet synchronous motors can simultaneously expand the motor's operating speed range and constant power operating range. They fully utilize the end leakage flux of permanent magnet motors, and when the motor is magnetically modulated, they channel the main magnetic flux rather than blocking or obstructing it. This "conversion from blocking to channeling" approach fully utilizes the magnetic flux generated by the motor's permanent magnets, increasing motor efficiency. By adjusting the generator's air gap magnetic field, the system can maintain constant voltage operation despite random wind speed and load fluctuations. Hybrid excitation permanent magnet motors offer greater margin, allowing them to maintain their normal operating state as closely as possible during fault-tolerant operation. Thanks to their multi-port design, hybrid excitation motors can simultaneously output power from multiple lines, voltage levels, and even AC and DC.

[0007] However, hybrid excitation permanent magnet synchronous motors usually use electric excitation windings for hybrid excitation, which has large operating losses and large winding currents during starting. To achieve high starting torque, the corresponding current margin needs to be adapted, which significantly increases manufacturing costs and is not conducive to efficient magnetic regulation of the motor. Summary of the Invention

[0008] In order to solve the above problems, the present invention proposes an axial double-sided magnetized permanent magnet synchronous motor and a control method thereof, which adjusts the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes to adjust the magnetization amount of the end annular permanent magnet on the main magnetic flux of the motor, thereby realizing the main magnetic flux regulation of the motor.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides an axial double-sided magnetized permanent magnet synchronous motor, comprising: a stator, a rotor, an end annular sleeve and an annular permanent magnet;

[0011] The rotor is built into the stator, and end annular sleeves are provided at both ends of the rotor, and annular permanent magnets are provided in the end annular sleeves;

[0012] The rotor comprises a first rotor section and a second rotor section with opposite polarities, the first rotor section being provided with a first rib structure and an inner ring of magnetically conductive spokes connected to the first rib structure, the second rotor section being provided with a second rib structure and an outer ring of magnetically conductive spokes connected to the second rib structure, the inner ring of magnetically conductive spokes and the outer ring of magnetically conductive spokes extending to an end annular sleeve;

[0013] The inner wall and outer wall of the end annular sleeve correspond to the inner ring magnetic spokes and the outer ring magnetic spokes respectively. The magnetic flux generated by the annular permanent magnet on the end annular sleeve enters the stator and rotor air gap through the end annular sleeve, the inner and outer ring magnetic spokes and the rib structure to magnetize the main magnetic flux of the motor, and the magnetic flux is changed by adjusting the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes.

[0014] As an optional embodiment, the first rib structure and the second rib structure are staggered and formed with a staggered angle, so that the first rib structure and the second rib structure have opposite polarities.

[0015] As an optional implementation, the staggered angle is 360 / 2p degrees, where p is the number of motor pole pairs.

[0016] As an optional implementation, the number of motor pole pairs is greater than or equal to one.

[0017] As an optional embodiment, the inner ring magnetic conductive spokes and the outer ring magnetic conductive spokes have different radii, the same length and opposite polarities.

[0018] As an optional embodiment, the inner and outer walls of the end annular sleeve and the corresponding inner and outer ring magnetic spokes have the same polarity.

[0019] As an optional implementation, the air gap length is negatively correlated with the magnetic flux of the main magnetic flux of the motor.

[0020] As an optional embodiment, when the motor is started, the end annular sleeve and the annular permanent magnet are adjusted to be close to the inner and outer ring magnetic spokes to shorten the air gap length and increase the magnetic flux entering the main magnetic flux of the motor to magnetize the motor;

[0021] When the motor is started, the end annular sleeve and the annular permanent magnet are adjusted away from the inner and outer ring magnetic spokes to increase the air gap length and reduce the magnetic flux entering the main magnetic flux of the motor. The main magnetic flux of the motor is provided by the rotor, and the motor is in normal operation.

[0022] As an optional implementation, the air gap length is adjusted in a two-speed adjustment, a multi-speed adjustment or a stepless adjustment.

[0023] In a second aspect, the present invention provides a control method for an axial double-sided magnetized permanent magnet synchronous motor, which is applied to the axial double-sided magnetized permanent magnet synchronous motor described in the first aspect, comprising:

[0024] During the motor starting process, by adjusting the end annular sleeve and the annular permanent magnet, the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes is reduced. The magnetic flux generated by the annular permanent magnet enters the stator and rotor air gap through the end annular sleeve, the inner and outer ring magnetic spokes and the rib structure, and the main magnetic flux of the motor increases.

[0025] When the motor completes the starting process and is in normal operation, by adjusting the end annular sleeve and the annular permanent magnet, the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes is increased. The magnetic flux generated by the annular permanent magnet does not enter the stator and rotor air gap. The main magnetic flux of the motor is provided by the permanent magnets in the rotor slots, and the motor is in normal operation.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The motor of the present invention uses permanent magnets for flux regulation at the end, without adding additional electric excitation windings. The magnetic flux generated by the end permanent magnets is adjusted by mechanical means by adjusting the magnetic flux entering the main magnetic flux of the motor through the magnetic adjustment end rings on both sides. The rotor is composed of two rotor sections, each of which is provided with a staggered rib structure and is connected to the magnetic spokes on the rotor end shaft. The ribs of the two rotor sections are staggered at a certain angle, so that the polarity of the ribs and magnetic spokes of each rotor section is opposite to the polarity of the ribs and magnetic spokes of the other rotor section, and is used in conjunction with the inner and outer layers of the end permanent magnet magnetic adjustment rings to achieve "magnetization" of the motor by the end permanent magnets. The motor of the present invention achieves a significant enhancement of the starting ability of the permanent magnet motor and an improvement of the weak magnetic speed expansion capability with extremely low losses. The inherent support structure of the rotor is fully utilized to form a parallel magnetic circuit, reducing the design of additional parallel magnetic circuit mechanical structures. The structure is relatively simple and the manufacturing cost is relatively low.

[0028] The rotor shaft of the motor of this invention is designed with axial magnetic poles through magnetic spokes. This reduces the space occupied by the parallel magnetic circuit branches and facilitates the design of the end axial magnetic pole structure. The rotor is a conventional spoke-type permanent magnet rotor, but with a segmented structure. The spoke-type rotor's support is designed into the motor's magnetic field circuit. This clever magnetic field circuit design simplifies the motor's manufacturing process and facilitates practical fabrication. Its structural complexity and manufacturing cost are both lower than those of existing hybrid excitation permanent magnet motors.

[0029] From the perspective of mechanical structure, the motor of the present invention arranges the axial stator armature winding and the radial stator armature winding on the motor casing side. The motor has a well-integrated mechanical structure and a large heat dissipation area. Heat can be dissipated through the ends, and the heat dissipation performance is good. It can be applied to various complex working conditions under heavy loads and high speeds.

[0030] 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

[0031] 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.

[0032] Figure 1 A schematic diagram showing the outer ring of magnetic spokes of the motor rotor structure provided in Example 1 of the present invention;

[0033] Figure 2 A schematic diagram showing the inner ring of the magnetic spokes of the motor rotor structure provided in Example 1 of the present invention;

[0034] Figure 3 A schematic diagram of the overall structure of a motor provided in Example 1 of the present invention;

[0035] Among them, 1. First section of the rotor, 2. Second section of the rotor, 3. Permanent magnet, 4. First rib structure, 5. Second rib structure, 6. Outer ring magnetic spokes, 7. Inner ring magnetic spokes, 8. End annular sleeve, 9. Annular permanent magnet, 10. Stator, 11. Armature winding, 12. Stator teeth, 13. Stator slots. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] 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.

[0038] 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.

[0039] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0040] Example 1

[0041] This embodiment provides an axial double-sided magnetized permanent magnet synchronous motor, comprising: a stator 10, a rotor, an end annular sleeve 8 and an annular permanent magnet 9;

[0042] The rotor is built into the stator 10 and is placed coaxially with the stator 10;

[0043] End annular sleeves 8 are provided at both ends of the rotor, and annular permanent magnets 9 are provided in the end annular sleeves 8;

[0044] The rotor comprises a first rotor section 1 and a second rotor section 2 with opposite polarities. The first rotor section 1 is provided with a first rib structure 4 and an inner ring of magnetically conductive spokes 7 connected to the first rib structure 4. The second rotor section 2 is provided with a second rib structure 5 and an outer ring of magnetically conductive spokes 6 connected to the second rib structure 5. The inner ring of magnetically conductive spokes 7 and the outer ring of magnetically conductive spokes 6 extend to an end annular sleeve 8.

[0045] The inner wall and outer wall of the end annular sleeve 8 correspond to the inner ring magnetic spokes 7 and the outer ring magnetic spokes 6 respectively. The magnetic flux generated by the annular permanent magnet 9 on the end annular sleeve 8 enters the stator and rotor air gap through the end annular sleeve, the inner and outer ring magnetic spokes and the rib structure to magnetize the main magnetic flux of the motor, and the magnetic flux is changed by adjusting the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes.

[0046] like Figure 1-Figure 3 As shown, the rotor comprises a first rotor section 1 and a second rotor section 2 having the same structure, opposite polarities and coaxial connection;

[0047] The yoke of the first section rotor 1 is provided with p first rib structures 4 distributed in a staggered manner, and the yoke of the second section rotor 2 is provided with p second rib structures 5 distributed in a staggered manner, where p is the number of pole pairs of the motor;

[0048] The first rib structure 4 and the second rib structure 5 are staggered at a certain angle, so that the first rib structure 4 and the second rib structure 5 present opposite magnetic polarities, thereby making the two sections of the rotor present opposite magnetic polarities.

[0049] As an optional implementation, the stagger angle is related to the number of poles and is 360 / 2p degrees.

[0050] As an optional implementation, the rib structure is respectively connected to the N pole or S pole of the corresponding rotor segment, so that the rib structure of the rotor segment and the magnetic spokes connected thereto have the same polarity, and the rib structures and magnetic spokes of the two rotor segments have opposite polarities.

[0051] In this embodiment, an inner ring of magnetically conductive spokes 7 is provided at the end of the first rotor section 1 and connected to the first rib structure 4. An outer ring of magnetically conductive spokes 6 is provided at the end of the second rotor section 2 and connected to the second rib structure 5. The inner ring of magnetically conductive spokes 7 and the outer ring of magnetically conductive spokes 6 have different radii, the same length, and opposite polarities.

[0052] The inner ring magnetic spokes 7 and the outer ring magnetic spokes 6 extend to both ends of the rotor. End annular sleeves 8 are provided at both ends of the rotor. An annular permanent magnet 9 is provided in the end annular sleeve 8. The magnetic polarity of the annular permanent magnet 9 makes the inner and outer walls of the end annular sleeve have the same polarity as the corresponding inner and outer ring magnetic spokes.

[0053] In this embodiment, the annular permanent magnet generates magnetic flux on the end annular sleeve, and the magnetic flux enters the stator and rotor air gap through the "end annular sleeve-inner and outer ring magnetic spokes-rib structure-rotor yoke", thereby magnetizing the main magnetic flux of the motor.

[0054] In this embodiment, the air gap length between the inner and outer walls of the end annular sleeve and the corresponding inner and outer ring magnetic spokes is adjustable. The end annular sleeve is a movable component and can be axially adjusted by a mechanical device. The magnetic flux is changed by adjusting the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes to achieve magnetization and component removal during the motor starting process.

[0055] In this embodiment, the air gap length is negatively correlated with the amount of magnetic flux of the annular permanent magnet entering the main magnetic flux of the motor;

[0056] When the air gap length decreases, the magnetic flux of the annular permanent magnet entering the main magnetic flux of the motor increases, and the starting ability of the motor is enhanced, thereby achieving magnetization of the motor;

[0057] When the air gap length increases, the magnetic flux of the annular permanent magnet entering the main magnetic flux of the motor decreases, and the motor is in a normal operating state.

[0058] As an optional embodiment, the movable mode of the end annular sleeve can be designed to have two adjustment gears of air gap "large-small", corresponding to the starting state and the normal operating state;

[0059] Or it can be designed with multi-stage adjustment of multiple gears of air gap from large to small, which can provide different magnetic fluxes for the motor through the end annular sleeve and annular permanent magnet according to the changes in starting / running status;

[0060] Or it can be designed for stepless adjustment, driven by a servo motor to achieve stepless adjustment of the end air gap to correspond to various motor air gap main magnetic fluxes.

[0061] In this embodiment, during the motor starting process, the end annular sleeve and its annular permanent magnet are adjusted to be close to the magnetic spokes through the adjustment of the mechanical movable component, shortening the air gap between the two components. This allows the magnetic flux generated by the annular permanent magnets at both ends of the rotor to enter the stator-rotor air gap through the "end annular sleeve-magnetic spokes-rotor ribs-rotor yoke", thereby increasing the main magnetic flux of the motor, increasing the starting torque of the motor, reducing the starting current, and enhancing the starting capacity, thereby improving the starting capacity of the motor.

[0062] After the motor completes the starting process, the end annular sleeve and its annular permanent magnet are adjusted away from the magnetic spokes through a mechanical movable device to increase the air gap between the two components. At this time, the magnetic flux of the annular permanent magnet no longer enters the stator. The magnetic flux for the motor operation is provided by the permanent magnet on the rotor, eliminating the influence of the end annular sleeve on the motor magnetic circuit and keeping the motor in normal operation.

[0063] As an optional implementation manner, the inner ring magnetic conductive spokes and the outer ring magnetic conductive spokes are made of pure steel.

[0064] As an optional embodiment, the rotor may be a solid rotor made of a soft magnetic composite material with high magnetic permeability. The solid rotor has high magnetic permeability and may also be made of laminated silicon steel sheets.

[0065] As an optional embodiment, the magnetic spokes and the rotor ribs can be installed by fasteners or fixed by screws, and can be fixed as a whole by epoxy resin depending on the mechanical strength requirements;

[0066] Alternatively, the rotor and the magnetic spokes may be integrally cast from solid steel to enhance connection reliability and mechanical strength.

[0067] As an optional embodiment, the rotor has rotor slots, each containing a permanent magnet 3. These permanent magnets 3 are connected in series and parallel to achieve a "magnetic focusing effect," generating magnetic poles on the rotor. Adjacent permanent magnets are magnetized in opposite directions, generating radial magnetic poles along the radial direction between the two adjacent permanent magnets and the rotor core between them. The magnetic flux generated by the permanent magnets passes through the radial magnetic poles, across the air gap, into the stator core, and interlinks with the armature winding to form the main magnetic flux. The motor's main magnetic flux and the magnetic flux generated by the stator armature winding interact to generate torque.

[0068] Then, when the permanent magnet synchronous motor is working, the magnetic flux generated by the permanent magnet passes through the radial magnetic poles and the air gap into the stator core and interlinks with the armature winding to form the main magnetic flux; in addition, the magnetic flux generated by the end annular sleeve and the annular permanent magnet can also pass through the "end annular sleeve-magnetic spokes-rotor ribs-rotor yoke" to enter the stator 10 to form the main magnetic flux of the motor, and the magnetic flux entering the main magnetic flux of the motor can be adjusted.

[0069] As an optional embodiment, the permanent magnet 3 can be made of high-performance permanent magnet materials, such as neodymium iron boron, rare earth cobalt, etc., or low-coercivity permanent magnet materials, such as aluminum nickel cobalt or ferrite, etc.

[0070] In this embodiment, the stator 10 is formed by laminating silicon steel sheets. The stator 10 includes stator slots 13, stator teeth 12, and a stator yoke. The armature winding 11 is placed in the stator slots 13.

[0071] As an optional implementation, the armature winding 11 may be a single-layer winding or a double-layer winding.

[0072] As an optional implementation, the armature winding 11 can be divided into a distributed winding, a concentrated winding or a lapped winding.

[0073] As an optional implementation, the number of poles of the armature winding 11 is consistent with the number of rotor poles.

[0074] 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.

[0075] As an optional implementation, the number of motor phases m≥3, and the number of motor pole pairs p≥1.

[0076] 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.

[0077] Example 2

[0078] This embodiment provides a torque driving method for the axial double-sided magnetized permanent magnet synchronous motor described in Example 1. The current applied to the stator armature winding interacts with the rotor main magnetic field to generate driving torque. The annular sleeves and their annular permanent magnets at both ends of the motor are mechanically movable to adjust the air gap between them and the rotor magnetic spokes to achieve regulation of the motor's main magnetic flux. Specifically, the method includes:

[0079] During the motor starting process, the annular sleeves and annular permanent magnets on both sides of the motor are adjusted through mechanical movable parts to reduce the air gap between the end annular sleeves and the rotor magnetic spokes. The magnetic flux generated by the end annular permanent magnets enters the motor air gap through the "annular sleeve-magnetic spokes-rotor ribs-rotor yoke", increasing the main magnetic flux of the motor and enhancing the starting ability.

[0080] When the motor completes the starting process and is in normal operation, the annular sleeves and annular permanent magnets on both sides of the motor are adjusted through mechanical movable parts to increase the air gap between the end annular sleeves and the rotor magnetic spokes. The magnetic flux generated by the end annular permanent magnets no longer enters the rotor, and the main magnetic flux of the motor is entirely provided by the permanent magnets in the motor rotor slots. The motor is in normal operation.

[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. An axial double-sided magnetization permanent magnet synchronous motor, characterized in that: include: stator, rotor, end annular sleeve and annular permanent magnet; The rotor is built into the stator, and end annular sleeves are provided at both ends of the rotor, and annular permanent magnets are provided in the end annular sleeves; The rotor comprises a first rotor section and a second rotor section with opposite polarities, the first rotor section being provided with a first rib structure and an inner ring of magnetically conductive spokes connected to the first rib structure, the second rotor section being provided with a second rib structure and an outer ring of magnetically conductive spokes connected to the second rib structure, the inner ring of magnetically conductive spokes and the outer ring of magnetically conductive spokes extending to an end annular sleeve; The inner wall and outer wall of the end annular sleeve correspond to the inner ring magnetic spokes and the outer ring magnetic spokes respectively. The magnetic flux generated by the annular permanent magnet on the end annular sleeve enters the stator and rotor air gap through the end annular sleeve, the inner and outer ring magnetic spokes and the rib structure to magnetize the main magnetic flux of the motor. The magnetic flux can be changed by adjusting the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes. The first rib structure and the second rib structure are staggered and arranged at a staggered angle, so that the first rib structure and the second rib structure have opposite polarities; The inner ring magnetic spokes and the outer ring magnetic spokes have different radii, the same length and opposite polarities; The inner and outer walls of the end annular sleeve and the corresponding inner and outer ring magnetic spokes have the same polarity.

2. The axial double-sided magnetization 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. The axial double-sided magnetization 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. The axial double-sided magnetization permanent magnet synchronous motor according to claim 1, characterized in that: The air gap length is negatively correlated with the magnetic flux of the motor's main magnetic flux.

5. The axial double-sided magnetization permanent magnet synchronous motor according to claim 4, characterized in that: When the motor is starting, the end annular sleeve and the annular permanent magnet are adjusted to be close to the inner and outer ring magnetic spokes to shorten the air gap length and increase the magnetic flux generated by the annular permanent magnet entering the main magnetic flux of the motor to magnetize the motor; When the motor is started, the end annular sleeve and the annular permanent magnet are adjusted away from the inner and outer ring magnetic spokes to increase the air gap length and reduce the amount of magnetic flux generated by the annular permanent magnet entering the main magnetic flux of the motor. The main magnetic flux of the motor is provided by the rotor, and the motor is in normal operation.

6. The axial double-sided magnetization permanent magnet synchronous motor according to claim 5, characterized in that: The air gap length can be adjusted in two-stage adjustment, multi-stage adjustment or stepless adjustment.

7. A control method for an axial double-sided magnetization permanent magnet synchronous motor, characterized in that: The axial double-sided magnetization permanent magnet synchronous motor according to any one of claims 1 to 6 comprises: During the motor starting process, by adjusting the end annular sleeve and the annular permanent magnet, the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes is reduced. The magnetic flux generated by the annular permanent magnet enters the stator and rotor air gap through the end annular sleeve, the inner and outer ring magnetic spokes and the rib structure, and the main magnetic flux of the motor increases. When the motor completes the starting process and is in normal operation, by adjusting the end annular sleeve and the annular permanent magnet, the air gap length between the end annular sleeve and the inner and outer ring magnetic spokes is increased. The magnetic flux generated by the annular permanent magnet does not enter the stator and rotor air gap. The main magnetic flux of the motor is provided by the permanent magnets in the rotor slots, and the motor is in normal operation.

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