Hybrid magnetic bearing and flywheel energy storage system

Abstract

This application relates to a hybrid magnetic bearing and a flywheel energy storage system. The hybrid magnetic bearing includes a stator assembly, a rotor assembly, and a permanent magnet assembly. The stator assembly includes a radial stator and an axial stator. The rotor assembly's shaft movably passes through the radial and axial stators. A radial air gap is formed between the shaft and a first magnetic pole, and an axial air gap is formed between the shaft and a second magnetic pole. The permanent magnet assembly includes a first permanent magnet and a second permanent magnet that are axially magnetized. In a static or equilibrium position, a first bias magnetic flux generated by the first permanent magnet simultaneously penetrates the radial air gap and a portion of the axial air gap, providing radial and axial bias attraction. Simultaneously, a second bias magnetic flux generated by the second permanent magnet penetrates the axial air gap, further providing axial bias attraction. Thus, the rotor assembly can achieve stable levitation, while the current in the first and second coils is close to zero, resulting in low power consumption. Furthermore, the axial dimension can be shortened, increasing the power density and structural compactness of the flywheel energy storage system.

Description

Technical Field

[0001] This application relates to the field of magnetic levitation bearing technology, and in particular to a hybrid magnetic bearing and flywheel energy storage system. Background Technology

[0002] Flywheel energy storage systems are a physical energy storage technology that combines high efficiency, long lifespan, and high power density, and have significant application prospects in areas such as grid frequency regulation, smooth integration of renewable energy, and uninterrupted power supply for critical facilities. Its core lies in using magnetic bearings to achieve contactless, high-speed rotation of the flywheel rotor, thereby efficiently storing electrical energy in the form of kinetic energy.

[0003] Hybrid magnetic bearings, as key supporting components in flywheel energy storage systems, achieve stable levitation of the flywheel rotor through non-contact electromagnetic force, eliminating mechanical friction and wear, and enabling the flywheel rotor to operate at ultra-high speeds of tens of thousands of revolutions per minute, thereby storing large amounts of kinetic energy. However, the integration of hybrid magnetic bearings in related technologies is limited, and they generally suffer from problems such as large axial dimensions and high energy consumption. Summary of the Invention

[0004] Therefore, it is necessary to provide a hybrid magnetic bearing and flywheel energy storage system to address the problems of large axial dimensions and high energy consumption of hybrid magnetic bearings in related technologies.

[0005] In a first aspect, this application provides a hybrid magnetic bearing, comprising:

[0006] A stator assembly, comprising a radial stator and an axial stator, wherein the radial stator and the axial stator are coaxially arranged, the radial stator is provided with a first magnetic pole and a first coil, and the axial stator is provided with a second magnetic pole and a second coil;

[0007] A rotor assembly, the rotor assembly including a rotating shaft movably passing through the radial stator and the axial stator, a radial air gap forming between the rotating shaft and the first magnetic pole, and an axial air gap forming between the rotating shaft and the second magnetic pole; and

[0008] A permanent magnet assembly includes an axially magnetized first permanent magnet and a second permanent magnet. The first permanent magnet is disposed between the radial stator and the axial stator and is configured to generate a first bias magnetic flux through the radial air gap and at least a portion of the axial air gap to provide a radial bias attraction and at least a portion of the axial bias attraction. The second permanent magnet is disposed on the axial stator and is configured to generate a second bias magnetic flux through the axial air gap to provide an axial bias attraction.

[0009] In one embodiment, two second permanent magnets are provided, one of which is located at the end of the axial stator facing the radial stator, and the other is located at the end of the axial stator away from the radial stator, and the polarity of the two second permanent magnets is the same on opposite sides.

[0010] In one embodiment, the hybrid magnetic bearing further includes a first magnetic isolation ring and a second magnetic isolation ring, the first magnetic isolation ring and the second magnetic isolation ring being radially spaced along the shaft, and the first permanent magnet being disposed between the first magnetic isolation ring and the second magnetic isolation ring.

[0011] In one embodiment, the permanent magnet assembly further includes a third permanent magnet and a fourth permanent magnet. The third permanent magnet and the fourth permanent magnet are both annular structures and coaxially arranged. The third permanent magnet is located on the outer periphery of the rotating shaft, and the fourth permanent magnet is located on the outer periphery of the third permanent magnet. The magnetization direction of the third permanent magnet and the fourth permanent magnet is radial. The polarity of the side of the third permanent magnet facing the fourth permanent magnet is the same as the polarity of the side of the fourth permanent magnet facing the third permanent magnet.

[0012] In one embodiment, there are two of each of the third and fourth permanent magnets. The two third permanent magnets are located on the outer periphery of the rotating shaft and arranged along the axial direction of the rotating shaft. The two fourth permanent magnets are located on the outer periphery of the two third permanent magnets respectively. The polarities of the two third permanent magnets facing the fourth permanent magnets are opposite, and the polarities of the two fourth permanent magnets facing the third permanent magnets are opposite.

[0013] In one embodiment, the hybrid magnetic bearing further includes a third magnetic isolation ring disposed on the outer periphery of the shaft and located between the shaft and the third permanent magnet.

[0014] In one embodiment, the inner circumference of the radial stator is provided with a plurality of first magnetic poles, each of which is wound with a first coil. The plurality of first magnetic poles cooperate to form a plurality of magnetic pole units, and the plurality of magnetic pole units are evenly arranged along the circumference of the radial stator.

[0015] In one embodiment, each of the first coils of the same magnetic pole unit is supplied with alternating current of the same phase, while the first coils of different magnetic pole units are supplied with alternating current of different phases.

[0016] In one embodiment, the magnetic pole unit includes a large magnetic pole and two small magnetic poles. The two small magnetic poles are respectively disposed on both sides of the large magnetic pole along the circumference of the radial stator, and the large magnetic pole and the two small magnetic poles cooperate to form an E-shaped structure.

[0017] Secondly, this application also provides a flywheel energy storage system, including a flywheel rotor and a hybrid magnetic bearing as described in any of the above claims, wherein the shaft is part of the flywheel rotor and the hybrid magnetic bearing is used to levitate and support the flywheel rotor.

[0018] In the aforementioned hybrid magnetic bearing and flywheel energy storage system, in the static or equilibrium position, the first permanent magnet generates a first bias magnetic flux that simultaneously penetrates the radial air gap and at least part of the axial air gap, providing radial and axial bias attraction. Simultaneously, the second permanent magnet generates a second bias magnetic flux that penetrates the axial air gap, further providing axial bias attraction. Thus, under the combined action of the first and second permanent magnets, the rotor assembly can achieve stable levitation, while the current in the first and second coils is close to zero, resulting in low system power consumption. When the rotor assembly experiences radial displacement, adjusting the current in the first coil generates a first control magnetic flux that superimposes with the first bias magnetic flux at the radial air gap, forming a radial restoring force. When the rotor assembly experiences axial displacement, adjusting the current in the second coil generates a second control magnetic flux that superimposes with the second bias magnetic flux at the axial air gap, changing the magnetic flux density distribution in the axial air gap and forming an axial restoring force. In addition, the hybrid magnetic bearing adopts an integrated radial-axial structure, which can effectively shorten the axial dimension compared with the traditional separate radial and axial bearing structure, thereby improving the power density and structural compactness of the flywheel energy storage system. At the same time, the integrated structure reduces magnetic circuit connection losses, which is conducive to improving operating efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a hybrid magnetic bearing according to an embodiment of this application.

[0020] Figure 2 for Figure 1 The diagram shows a hybrid magnetic bearing from another perspective.

[0021] Figure 3 for Figure 1 The front view of the hybrid magnetic bearing shown.

[0022] Figure 4 for Figure 3 Sectional view along the middle AA.

[0023] Figure 5 for Figure 3 A cross-sectional view along the middle BB.

[0024] Figure 6 for Figure 3 A cross-sectional view along the center CC.

[0025] Figure 7 for Figure 1 The top view of the hybrid magnetic bearing shown.

[0026] Figure 8 for Figure 7 A sectional view along the middle DD.

[0027] Figure 9 This is a cross-sectional view of the axial stator of a hybrid magnetic bearing according to an embodiment of this application.

[0028] Figure 10 This is an assembly diagram of the shaft, third magnetic isolation ring and third permanent magnet of a hybrid magnetic bearing according to an embodiment of this application.

[0029] Explanation of icon numbers:

[0030] 10. Stator assembly; 11. Radial stator; 111. First magnetic pole; 1111. Large magnetic pole; 1112. Small magnetic pole; 12. Axial stator; 121. Second magnetic pole; 122. Receiving slot; 13. First coil; 14. Second coil; 20. Rotor assembly; 21. Shaft; 211. First magnetic conductive part; 212. Second magnetic conductive part; 30. Permanent magnet assembly; 31. First permanent magnet; 32. Second permanent magnet; 33. Third permanent magnet; 34. Fourth permanent magnet; 40. First magnetic isolation ring; 50. Second magnetic isolation ring; 60. Third magnetic isolation ring; 100. First bias flux; 200. Second bias flux; 300. First control flux; 400. Second control flux. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] One embodiment of this application provides a flywheel energy storage system, including a flywheel rotor and a hybrid magnetic bearing. The hybrid magnetic bearing utilizes non-contact electromagnetic force to achieve stable levitation of the flywheel rotor, eliminating mechanical friction and wear, enabling the flywheel rotor to operate at ultra-high speeds of tens of thousands of revolutions per minute, thereby storing a large capacity of kinetic energy.

[0033] See Figure 1 , Figure 3 and Figure 4 The hybrid magnetic bearing includes a stator assembly 10, a rotor assembly 20, and a permanent magnet assembly 30.

[0034] For example, a hybrid magnetic bearing has three degrees of freedom, including two radial degrees of freedom and one axial degree of freedom.

[0035] See Figure 1 and Figure 2 The stator assembly 10 includes a radial stator 11 and an axial stator 12. Both the radial stator 11 and the axial stator 12 are annular structures, and the radial stator 11 and the axial stator 12 are coaxially arranged. (See reference...) Figure 4 , Figure 5 and Figure 6 The radial stator 11 is equipped with a first coil 13, and the axial stator 12 is equipped with a second coil 14.

[0036] See Figure 4 The rotor assembly 20 includes a shaft 21. The shaft 21 extends along the arrangement direction of the radial stator 11 and the axial stator 12, and is movably inserted through the radial stator 11 and the axial stator 12.

[0037] It should be noted that in the flywheel energy storage system, the rotor assembly 20 is part of the flywheel rotor structure.

[0038] Among them, see Figure 7 and Figure 9 The radial stator 11 has a first magnetic pole 111, and the axial stator 12 has a second magnetic pole 121. The rotating shaft 21 is made of a high-strength magnetic alloy. (See reference...) Figure 10 The rotating shaft 21 has a first magnetically conductive part 211 at the position corresponding to the first magnetic pole 111, and a radial air gap is formed between the first magnetically conductive part 211 and the first magnetic pole 111. The rotating shaft 21 has a second magnetically conductive part 212 at the position corresponding to the second magnetic pole 121, and an axial air gap is formed between the second magnetically conductive part 212 and the second magnetic pole 121.

[0039] See Figure 4 , Figure 7 and Figure 8 The permanent magnet assembly 30 includes a first permanent magnet 31 and a second permanent magnet 32. The first permanent magnet 31 is disposed between the radial stator 11 and the axial stator 12 and is axially magnetized. The first permanent magnet 31 is configured to generate a first bias magnetic flux 100 that simultaneously penetrates the radial air gap and at least a portion of the axial air gap, providing radial bias attraction and at least a portion of axial bias attraction. The second permanent magnet 32 ​​is disposed on the axial stator 12 and is axially magnetized. The second permanent magnet 32 ​​is configured to generate a second bias magnetic flux 200 that penetrates the axial air gap, providing axial bias attraction.

[0040] In a static or equilibrium position, the first permanent magnet 31 generates a first bias magnetic flux 100 that simultaneously penetrates the radial air gap and at least part of the axial air gap, providing radial and at least part of the axial bias attraction. Simultaneously, the second permanent magnet 32 ​​generates a second bias magnetic flux 200 that penetrates the axial air gap, further providing axial bias attraction. Thus, under the combined action of the first permanent magnet 31 and the second permanent magnet 32, the rotor assembly 20 can achieve stable levitation, while the current in the first coil 13 and the second coil 14 is close to zero, resulting in low system power consumption.

[0041] When the rotor assembly 20 is radially offset, the current of the first coil 13 is adjusted, and the resulting first control flux 300 and the first bias flux 100 are superimposed at the radial air gap to form radial restoring forces Fx and Fy.

[0042] When the rotor assembly 20 is axially offset, the current of the second coil 14 is adjusted, and the resulting second control magnetic flux 400 and the second bias magnetic flux 200 are superimposed at the axial air gap, changing the magnetic flux density distribution of the axial air gap and forming an axial restoring force Fz.

[0043] Furthermore, the hybrid magnetic bearing in this embodiment adopts an integrated radial-axial structure, which can effectively shorten the axial dimension compared to the traditional separate structure of radial and axial bearings, thereby improving the power density and structural compactness of the flywheel energy storage system; at the same time, the integrated structure reduces magnetic circuit connection losses, which is conducive to improving operating efficiency.

[0044] In one embodiment, see Figure 4 Two second permanent magnets 32 are provided. One second permanent magnet 32 ​​is located at the end of the axial stator 12 facing the radial stator 11, and the other second permanent magnet 32 ​​is located at the end of the axial stator 12 away from the radial stator 11. The polarities of the two second permanent magnets 32 are the same on opposite sides.

[0045] For example, two second permanent magnets 32 are coaxially arranged.

[0046] Since there are two second permanent magnets 32, connected in series and superimposed, they jointly provide a higher axial bias magnetomotive force, increasing the static bias magnetic flux in the axial air gap, thereby generating a larger axial bias force to counteract the flywheel rotor's own weight. Simultaneously, because the axial bias force is mainly provided by the second permanent magnets 32, the second coil 14 only needs a small dynamic adjustment current to change the magnetic flux distribution in the axial air gap, achieving precise axial suspension control and helping to reduce the system's overall power consumption. Furthermore, it can further enhance the axial stiffness of the hybrid magnetic bearing.

[0047] For example, see Figure 9The axial stator 12 is provided with a receiving groove 122, and the second coil 14 is disposed in the receiving groove 122. The opening of the receiving groove 122 faces the outer peripheral surface of the rotating shaft 21. The second magnetic pole 121 includes an upper magnetic pole and a lower magnetic pole. The upper magnetic pole is disposed on the upper groove wall of the receiving groove 122, and the lower magnetic pole is disposed on the lower groove wall of the receiving groove 122. One of the second permanent magnets 32 is disposed on the side of the upper magnetic pole away from the second coil 14, and the other second permanent magnet 32 ​​is disposed on the side of the lower magnetic pole away from the second coil 14.

[0048] In one embodiment, see Figure 4 The permanent magnet assembly 30 also includes a third permanent magnet 33 and a fourth permanent magnet 34.

[0049] Optionally, both the third permanent magnet 33 and the fourth permanent magnet 34 are made of high-performance rare-earth permanent magnet material (neodymium iron boron). Of course, in other embodiments, the third permanent magnet 33 and the fourth permanent magnet 34 may also be made of other materials, and are not limited thereto.

[0050] Both the third permanent magnet 33 and the fourth permanent magnet 34 are located between the radial stator 11 and the axial stator 12. Both the third permanent magnet 33 and the fourth permanent magnet 34 are annular structures and coaxially arranged. The third permanent magnet 33 is located on the outer periphery of the rotating shaft 21, and the fourth permanent magnet 34 is located on the outer periphery of the third permanent magnet 33. It can be understood that the third permanent magnet 33 is sleeved outside the rotating shaft 21, and the fourth permanent magnet 34 is sleeved outside the third permanent magnet 33; that is, the fourth permanent magnet 34 is located between the first permanent magnet 31 and the third permanent magnet 33.

[0051] The magnetization direction of the third permanent magnet 33 and the fourth permanent magnet 34 is radial, and the polarity of the side of the third permanent magnet 33 facing the fourth permanent magnet 34 is the same as the polarity of the side of the fourth permanent magnet 34 facing the third permanent magnet 33.

[0052] By setting the third permanent magnet 33 and the fourth permanent magnet 34, passive stiffness can be provided, further reducing the energy consumption of active control, as detailed below:

[0053] In the static or equilibrium position, the rotor assembly 20 mainly relies on the radial bias attraction generated by the first permanent magnet 31 and the radial repulsion formed between the third permanent magnet 33 and the fourth permanent magnet 34 to achieve stable levitation.

[0054] When the rotor assembly 20 undergoes radial displacement due to load changes or external disturbances, the current in the first coil 13 is adjusted. The resulting first control flux 300 and the first bias flux 100 generated by the first permanent magnet 31 are vector-superimposed at the radial air gap, thereby generating a radial restoring force pointing towards the center position. Simultaneously, the radial displacement also changes the size of the air gap between the third permanent magnet 33 and the fourth permanent magnet 34, causing the radial repulsion between them to increase non-linearly, thus providing additional passive restoring force. In this way, the electromagnetic active control and the permanent magnet passive repulsion work together to quickly and smoothly pull the rotor assembly 20 back to the center position, achieving high-rigidity, high-precision, and low-energy-consumption radial suspension control.

[0055] In one embodiment, see Figure 4 Two third permanent magnets 33 and two fourth permanent magnets 34 are provided. The two third permanent magnets 33 are both located on the outer periphery of the rotating shaft 21 and are arranged along the axial direction of the rotating shaft 21. The two fourth permanent magnets 34 are respectively located on the outer periphery of the two third permanent magnets 33.

[0056] By incorporating two third permanent magnets 33 and two fourth permanent magnets 34, the two third permanent magnets 33 and two fourth permanent magnets 34 work together to cover a wider angular range, ensuring that the rotor assembly 20 receives a strong passive restoring force regardless of its radial displacement. Simultaneously, the radial repulsive forces generated by the two third permanent magnets 33 and two fourth permanent magnets 34 are superimposed and act together on the rotor assembly 20. When the rotor assembly 20 undergoes radial displacement, the air gap change synchronously generates a stronger resultant restoring force, thereby further improving the radial stiffness of the system.

[0057] Furthermore, the polarities of the two third permanent magnets 33 facing the fourth permanent magnet 34 are opposite, and the polarities of the two fourth permanent magnets 34 facing the third permanent magnets 33 are opposite. This arrangement helps to suppress the axial offset tendency of the rotor assembly 20 while maintaining the radial centering restoring force characteristics, thereby improving the passive stability of the system.

[0058] In one embodiment, see Figure 4 The hybrid magnetic bearing also includes a first magnetic isolation ring 40 and a second magnetic isolation ring 50.

[0059] Optionally, the first magnetic shielding ring 40 and the second magnetic shielding ring 50 are made of magnetic shielding aluminum. Of course, in other embodiments, the first magnetic shielding ring 40 and the second magnetic shielding ring 50 may also be made of other magnetic shielding materials, and are not limited thereto.

[0060] The first magnetic isolation ring 40 and the second magnetic isolation ring 50 are both disposed between the radial stator 11 and the axial stator 12, and are arranged radially at intervals along the rotating shaft 21. The first permanent magnet 31 is disposed between the first magnetic isolation ring 40 and the second magnetic isolation ring 50.

[0061] It is understandable that the first magnetic isolation ring 40 is located on the outer periphery of the first permanent magnet 31, and the second magnetic isolation ring 50 is located on the inner periphery of the first permanent magnet 31, that is, the first permanent magnet 31 is sandwiched between the first magnetic isolation ring 40 and the second magnetic isolation ring 50.

[0062] By setting the first magnetic isolation ring 40 and the second magnetic isolation ring 50, their non-magnetic properties can effectively block magnetic flux crosstalk between the first bias magnetic flux 100 and the repulsive magnetic flux generated by the third permanent magnet 33 and the fourth permanent magnet 34, ensuring that the first permanent magnet 31 and the third permanent magnet 33 and the fourth permanent magnet 34 work independently. At the same time, the first magnetic isolation ring 40 and the second magnetic isolation ring 50 constrain the first bias magnetic flux 100 within a predetermined path, reducing unnecessary magnetic leakage and improving magnetic energy utilization. In addition, since mutual interference between magnetic circuits is avoided, the first control magnetic flux 300 generated by the first coil 13 can be accurately superimposed with the first bias magnetic flux 100, thereby improving the control accuracy and levitation stability of the hybrid magnetic bearing.

[0063] In one embodiment, see Figure 4 The hybrid magnetic bearing also includes a third magnetic isolation ring 60. The third magnetic isolation ring 60 is disposed on the outer periphery of the rotating shaft 21 and is located between the rotating shaft 21 and the third permanent magnet 33.

[0064] Optionally, the third magnetic shielding ring 60 is made of magnetic shielding aluminum. Of course, in other embodiments, the third magnetic shielding ring 60 may also be made of other magnetic shielding materials, and is not limited thereto.

[0065] By setting a third magnetic isolation ring 60, which is located between the rotating shaft 21 and the third permanent magnet 33, the magnetic circuit is physically separated by its non-magnetic properties, preventing unnecessary magnetic flux leakage or magnetic circuit coupling. This ensures that the bias magnetic circuit and the radial repulsive magnetic circuit are independent of each other and do not interfere with each other, thereby achieving magnetic circuit decoupling and improving control accuracy.

[0066] In one embodiment, the thickness of the radial stator 11 is greater than the thickness of the axial stator 12. By thickening the radial stator 11, on the one hand, the magnetic cross-sectional area of ​​the first magnetic pole 111 can be increased, reducing the magnetic reluctance of the magnetic circuit at that location and improving the air gap magnetic flux density and output magnetic force; on the other hand, by optimizing the radial magnetic field distribution, edge effects can be suppressed, and magnetic field utilization efficiency can be improved. In addition, the mechanical structural strength of the stator assembly 10 can be enhanced, the deformation of the hybrid magnetic bearing can be suppressed, thereby improving the structural reliability of the hybrid magnetic bearing. At the same time, it can also provide a larger heat dissipation surface area, which is beneficial for heat dissipation and temperature rise control, improving the thermal stability of the hybrid magnetic bearing, reducing the failure rate, and ensuring the long-term reliable operation of the flywheel energy storage system under harsh conditions.

[0067] In one embodiment, see Figure 5 and Figure 7 The radial stator 11 has a plurality of first magnetic poles 111 on its inner circumference, and a first coil 13 is wound around each first magnetic pole 111. The plurality of first magnetic poles 111 cooperate to form a plurality of magnetic pole units, and the plurality of magnetic pole units are evenly arranged along the circumference of the radial stator 11.

[0068] Furthermore, each first coil 13 of the same magnetic pole unit is supplied with alternating current of the same phase, while the first coil 13 of different magnetic pole units are supplied with alternating current of different phases.

[0069] Each magnetic pole unit is equivalent to a phase winding. The magnetomotive forces of each magnetic pole in the same magnetic pole unit are superimposed in phase, so that the direction of the radial resultant force generated by the magnetic pole unit is fixed, which makes it easy to achieve independent control.

[0070] When different phases of alternating current are applied to different magnetic pole units, a circumferentially rotating magnetic field can be formed on the inner circumference of the stator. By adjusting the amplitude and phase of the current in each phase, a levitation force pointing in any radial direction can be synthesized, thereby achieving precise radial position control of the rotor assembly 20. Simultaneously, the use of AC differential control provides faster dynamic response and can meet the real-time adjustment requirements of levitation force in high-speed rotors. Furthermore, the combination of multiple magnetic pole units with multi-phase AC energization results in a more uniform radial air gap magnetic flux density distribution, reducing local saturation and improving the linearity of the electromagnetic force.

[0071] For example, see Figure 7 The system has three magnetic pole units, which are evenly distributed along the circumference of the radial stator 11. Each first coil 13 within the same magnetic pole unit is supplied with a current of equal magnitude and in the same direction. The three magnetic pole units are energized in a three-phase AC mode, with corresponding three-phase control currents i... A1 i B1 i C1 (i A1 +i B1 +i C1 =0), used to generate a dynamically adjustable control magnetic field.

[0072] In one embodiment, see Figure 5 and Figure 7 The magnetic pole unit includes a large magnetic pole 1111 and two small magnetic poles 1112. The two small magnetic poles 1112 are respectively located on both sides of the large magnetic pole 1111 along the radial direction of the stator 11. The large magnetic pole 1111 and the two small magnetic poles 1112 cooperate to form an E-type structure.

[0073] For example, there are three magnetic pole units, that is, the radial stator 11 has nine first magnetic poles 111, including three large magnetic poles 1111 and six small magnetic poles 1112. The three large magnetic poles 1111 are arranged circumferentially along the radial stator 11, and two small magnetic poles 1112 are provided between two adjacent large magnetic poles 1111.

[0074] Furthermore, the magnetic pole area of ​​the large magnetic pole 1111 is twice that of the small magnetic pole 1112, and the number of turns of the first coil 13 on the large magnetic pole 1111 is twice the number of turns of the first coil 13 on the small magnetic pole 1112.

[0075] The hybrid magnetic bearing in this embodiment adopts an E-type magnetic pole unit. This E-type structure makes fuller use of and optimizes the limited space, and can effectively increase the number of magnetic poles within the same volume, thereby improving the electromagnetic load-bearing capacity per unit space.

[0076] The hybrid magnetic bearing in this embodiment employs a three-pole AC magnetic bearing design, which has a lower energy consumption base compared to traditional DC magnetic bearings. Simultaneously, the first permanent magnet 31 provides radial bias attraction and at least partial axial bias attraction, while the second permanent magnet 32 ​​provides axial bias attraction, ensuring that static levitation consumes almost no electrical energy. The first coil 13 and the second coil 14 are only energized during dynamic adjustment, further reducing energy consumption. Furthermore, the third permanent magnet 33 and the fourth permanent magnet 34 provide passive radial and axial stiffness, reducing the adjustment burden on the active control system and effectively lowering the control current. This synergy reduces the overall system power consumption.

[0077] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0078] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0079] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0080] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0081] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A hybrid magnetic bearing, characterized in that, include: A stator assembly, comprising a radial stator and an axial stator, wherein the radial stator and the axial stator are coaxially arranged, the radial stator is provided with a first magnetic pole and a first coil, and the axial stator is provided with a second magnetic pole and a second coil; A rotor assembly, the rotor assembly including a rotating shaft, the rotating shaft being movably disposed between the radial stator and the axial stator, a radial air gap being formed between the rotating shaft and the first magnetic pole, and an axial air gap being formed between the rotating shaft and the second magnetic pole; as well as A permanent magnet assembly includes an axially magnetized first permanent magnet and a second permanent magnet. The first permanent magnet is disposed between the radial stator and the axial stator and is configured to generate a first bias magnetic flux through the radial air gap and at least a portion of the axial air gap to provide a radial bias attraction and at least a portion of the axial bias attraction. The second permanent magnet is disposed on the axial stator and is configured to generate a second bias magnetic flux through the axial air gap to provide an axial bias attraction.

2. The hybrid magnetic bearing according to claim 1, characterized in that, There are two second permanent magnets, one of which is located at the end of the axial stator facing the radial stator, and the other is located at the end of the axial stator away from the radial stator, and the polarity of the two second permanent magnets is the same on opposite sides.

3. The hybrid magnetic bearing according to claim 1, characterized in that, The hybrid magnetic bearing further includes a first magnetic isolation ring and a second magnetic isolation ring, which are radially spaced along the shaft. The first permanent magnet is disposed between the first magnetic isolation ring and the second magnetic isolation ring.

4. The hybrid magnetic bearing according to claim 1, characterized in that, The permanent magnet assembly further includes a third permanent magnet and a fourth permanent magnet. The third permanent magnet and the fourth permanent magnet are both annular structures and coaxially arranged. The third permanent magnet is located on the outer periphery of the rotating shaft, and the fourth permanent magnet is located on the outer periphery of the third permanent magnet. The magnetization direction of the third permanent magnet and the fourth permanent magnet is radial. The polarity of the side of the third permanent magnet facing the fourth permanent magnet is the same as the polarity of the side of the fourth permanent magnet facing the third permanent magnet.

5. The hybrid magnetic bearing according to claim 4, characterized in that, Two of each of the third and fourth permanent magnets are provided. The two third permanent magnets are provided on the outer periphery of the rotating shaft and arranged along the axial direction of the rotating shaft. The two fourth permanent magnets are provided on the outer periphery of the two third permanent magnets respectively. Among them, the polarities of the two third permanent magnets facing the side of the fourth permanent magnet are different, and the polarities of the two fourth permanent magnets facing the side of the third permanent magnet are different.

6. The hybrid magnetic bearing according to claim 4, characterized in that, The hybrid magnetic bearing also includes a third magnetic isolation ring, which is disposed on the outer periphery of the rotating shaft and located between the rotating shaft and the third permanent magnet.

7. The hybrid magnetic bearing according to claim 1, characterized in that, The radial stator has a plurality of first magnetic poles on its inner circumference, and each first magnetic pole is wound with a first coil. The plurality of first magnetic poles cooperate to form a plurality of magnetic pole units, and the plurality of magnetic pole units are evenly arranged along the circumference of the radial stator.

8. The hybrid magnetic bearing according to claim 7, characterized in that, The first coils of the same magnetic pole unit are supplied with alternating current of the same phase, while the first coils of different magnetic pole units are supplied with alternating current of different phases.

9. The hybrid magnetic bearing according to claim 7, characterized in that, The magnetic pole unit includes a large magnetic pole and two small magnetic poles. The two small magnetic poles are respectively located on both sides of the large magnetic pole along the circumference of the radial stator. The large magnetic pole and the two small magnetic poles cooperate to form an E-shaped structure.

10. A flywheel energy storage system, characterized in that, It includes a flywheel rotor and a hybrid magnetic bearing as described in any one of claims 1 to 9, wherein the shaft is part of the flywheel rotor and the hybrid magnetic bearing is used to levitate and support the flywheel rotor.

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