Flywheel energy storage device

Abstract

The application relates to the technical field of flywheel energy storage, in particular to a flywheel energy storage device, which comprises a shell, a first motor assembly, the first motor assembly comprising a first stator and a first rotor, the first rotor being magnetically suspended in the shell in the axial direction when the flywheel energy storage device is powered on, a second motor assembly, the second motor assembly comprising a second stator and a second rotor, the second rotor being magnetically suspended in the shell in the axial direction when the flywheel energy storage device is powered on, and a controller, the controller controlling synchronous movement of the first rotor and the second rotor. Thus, by arranging the first motor assembly and the second motor assembly and making the controller control synchronous movement or independent movement of the first rotor and the second rotor, not only can the flywheel energy storage device be redundantly protected, but also the large torque generated in the cyclic charging and discharging process can be avoided, and the over-temperature problem caused by the large torque and high power can be avoided, and the ability of long-time continuous cyclic charging and discharging can be improved.

Description

Technical Field

[0001] This invention relates to the field of flywheel energy storage technology, and in particular to a flywheel energy storage device. Background Technology

[0002] Flywheel energy storage devices are a type of energy storage that uses an electric motor to drive a flywheel to rotate at high speed, and then uses the flywheel to drive a generator to produce electricity when needed. They are characterized by high efficiency, long lifespan, high safety, and environmental friendliness.

[0003] In related technologies, the structural design of flywheel energy storage devices is not reasonable enough. The torque is too large during startup and shutdown. In order to achieve the purpose of short-term high-power cyclic charging and discharging, it will generate excessive torque on the rotor. At the same time, it will cause the motor stator and rotor to generate high temperature, which will affect the service life of the flywheel energy storage device. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a flywheel energy storage device with improved performance.

[0005] A flywheel energy storage device according to an embodiment of the present invention includes: a housing having an accommodating space within it; a first motor assembly disposed in the accommodating space and including a first stator and a first rotor, the first stator being fixedly connected to the housing, at least a portion of the first rotor being disposed inside the first stator and radially clearance-fitted with the first stator, wherein when the flywheel energy storage device is powered on and started, the first rotor is magnetically levitated axially within the housing; a second motor assembly disposed in the accommodating space and spaced below the first motor assembly, the second motor assembly including a second stator and a second rotor, the second stator being fixedly connected to the housing, at least a portion of the second rotor being disposed inside the second stator and radially clearance-fitted with the second stator, wherein when the flywheel energy storage device is powered on and started, the second rotor is magnetically levitated axially within the housing; and a controller controlling the first rotor and the second rotor to move synchronously.

[0006] Therefore, by setting up a first motor assembly and a second motor assembly, and enabling the controller to control the first rotor and the second rotor to move synchronously or independently, not only can redundant protection of the flywheel energy storage device be achieved, but also the large torque generated during cyclic charging and discharging, as well as the overheating problem caused by large torque and high power, can be avoided, thereby improving the ability to continuously cycle charge and discharge for a long time.

[0007] In some examples of the present invention, a first synchronizing element is provided at the end of the first rotor facing the second rotor, and a second synchronizing element is provided at the end of the second rotor facing the first rotor. The first synchronizing element and the second synchronizing element are adapted to realize the synchronous movement of the first rotor and the second rotor.

[0008] In some examples of the present invention, the first synchronizing element includes a plurality of permanent magnets, the second synchronizing element includes a plurality of permanent magnets, a magnetic attraction is formed between the first synchronizing element and the second synchronizing element, and the controller controls the first rotor and the second rotor to move closer together in the vertical direction to control the first rotor and the second rotor to move synchronously.

[0009] In some examples of the present invention, the first rotor includes: a first motor rotor and a first rotor flywheel, the first motor rotor and the first rotor flywheel being coaxially arranged and connected to each other, the first motor rotor being located above the first rotor flywheel, and the first motor rotor being disposed inside the first stator and radially clearance-fitted with the first stator; the second rotor includes: a second motor rotor and a second rotor flywheel, the second motor rotor and the second rotor flywheel being coaxially arranged and connected to each other, the second motor rotor being located below the second rotor flywheel, and the second motor rotor being disposed inside the second stator and radially clearance-fitted with the second stator; the first synchronizing element is disposed on the side of the first rotor flywheel facing the second rotor flywheel, and the second synchronizing element is disposed on the side of the second rotor flywheel facing the first rotor flywheel.

[0010] In some examples of the present invention, the housing includes an outer cover extending in a vertical direction. In the vertical direction, a first axial magnetic levitation bearing, an intermediate magnetic levitation assembly, and a second axial magnetic levitation bearing are sequentially spaced apart on the sidewall of the outer cover facing the receiving space. The first axial magnetic levitation bearing, the intermediate magnetic levitation assembly, and the second axial magnetic levitation bearing are electrically connected to the controller. The intermediate magnetic levitation assembly includes a third axial magnetic levitation bearing and a fourth axial magnetic levitation bearing. The third axial magnetic levitation bearing is located above the fourth axial magnetic levitation bearing. In the vertical direction, a first rotor flywheel is located between the first axial magnetic levitation bearing and the third axial magnetic levitation bearing, and a second rotor flywheel is located between the second axial magnetic levitation bearing and the fourth axial magnetic levitation bearing.

[0011] In some examples of the present invention, the outer cover includes: a first outer cover and a second outer cover, the second outer cover being connected below the first outer cover, a first axial magnetic levitation bearing being disposed on the side wall of the first outer cover facing the receiving space, an intermediate magnetic levitation assembly being disposed on the side wall of the first outer cover facing the receiving space, a second axial magnetic levitation bearing being disposed on the side wall of the second outer cover facing the receiving space, a first motor assembly and a second rotor flywheel being disposed inside the first outer cover, and a second stator and a second motor rotor being disposed inside the second outer cover.

[0012] In some examples of the present invention, the housing further includes a first end cap assembly disposed at the upper end of the outer cover. The first end cap assembly includes a first end cap body and a first radial magnetic levitation bearing. The first motor rotor is at least partially located inside the first end cap body and is radially clearance-fitted with the first end cap body. The first radial magnetic levitation bearing is disposed on the side of the first end cap body facing the first motor rotor. The intermediate magnetic levitation assembly further includes a third radial magnetic levitation bearing. The first rotor flywheel is at least partially disposed within the third radial magnetic levitation bearing and is radially spaced from the third radial magnetic levitation bearing.

[0013] In some examples of the present invention, a first radial sensor is disposed in the first end cap body, and the intermediate magnetic levitation assembly further includes a third radial sensor, wherein the first radial sensor and the third radial sensor are electrically connected to the controller respectively.

[0014] In some examples of the present invention, the housing further includes a second end cap assembly disposed at the lower end of the outer cover. The second end cap assembly includes a second end cap body and a second radial magnetic levitation bearing. The second motor rotor is at least partially located inside the second end cap body and is radially clearance-fitted with the second end cap body. The second radial magnetic levitation bearing is disposed on the side of the second end cap body facing the second motor rotor. The intermediate magnetic levitation assembly further includes a fourth radial magnetic levitation bearing. The second rotor flywheel is at least partially disposed within the fourth radial magnetic levitation bearing and is radially spaced from the fourth radial magnetic levitation bearing.

[0015] In some examples of the present invention, a second radial sensor is disposed in the body of the second end cap, and the intermediate magnetic levitation assembly further includes a fourth radial sensor, wherein the second radial sensor and the fourth radial sensor are electrically connected to the controller.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a schematic diagram of a flywheel energy storage device according to an embodiment of the present invention;

[0019] Figure 2 This is a cross-sectional view of a flywheel energy storage device according to an embodiment of the present invention along the AA direction;

[0020] Figure 3 This is an exploded view of a flywheel energy storage device according to an embodiment of the present invention;

[0021] Figure 4 This is a partial schematic diagram of a flywheel energy storage device according to an embodiment of the present invention.

[0022] Figure label:

[0023] 100. Flywheel energy storage equipment;

[0024] 10. Shell;

[0025] 11. Outer cover; 111. First outer cover; 1111. First axial magnetic levitation bearing; 1112. Intermediate magnetic levitation assembly; 112. Second outer cover; 1121. Second axial magnetic levitation bearing;

[0026] 12. First end cap assembly; 121. First end cap body; 122. First radial magnetic levitation bearing;

[0027] 13. Second end cap assembly; 131. Second end cap body; 132. Second radial magnetic levitation bearing;

[0028] 20. First motor assembly; 21. First stator; 22. First rotor; 221. First motor rotor; 222. First rotor flywheel; 223. First synchronizing element;

[0029] 30. Second motor assembly; 31. Second stator; 32. Second rotor; 321. Second motor rotor; 322. Second rotor flywheel; 323. Second synchronizing element. Detailed Implementation

[0030] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0031] The following is for reference. Figures 1-4 A flywheel energy storage device 100 according to an embodiment of the present invention is described.

[0032] Combination Figures 1-3 As shown, the flywheel energy storage device 100 according to the present invention may mainly include: a housing 10, a first motor assembly 20, a second motor assembly 30, and a controller.

[0033] The housing 10 contains a receiving space. A first motor assembly 20 is disposed within the receiving space. The first motor assembly 20 may include a first stator 21 and a first rotor 22. The first stator 21 is fixedly connected to the housing 10. At least a portion of the first rotor 22 is disposed inside the first stator 21 and radially clearance-fitted with the first stator 21. The first rotor 22 is selectively magnetically levitated within the housing 10 in the axial direction. A second motor assembly 30 is disposed within the receiving space and spaced below the first motor assembly 20. The second motor assembly 30 may include a second stator 31 and a second rotor 32. The second stator 31 is fixedly connected to the housing 10. At least a portion of the second rotor 32 is disposed inside the second stator 31 and radially clearance-fitted with the second stator 31. The second rotor 32 is selectively magnetically levitated within the housing 10 in the axial direction. A controller controls the first rotor 22 and the second rotor 32 to selectively move synchronously. It is understood that the axial direction is the same as the vertical direction, and the radial direction is perpendicular to the axial direction.

[0034] Specifically, by forming a receiving space within the housing 10, creating a vacuum environment within the receiving space, and placing both the first motor assembly 20 and the second motor assembly 30 within this receiving space, the wind resistance of the first rotor 22 and the second rotor 32 at high speeds can be reduced. Furthermore, by selectively magnetically levitizing both the first rotor 22 and the second rotor 32 axially within the housing 10, specifically, when the flywheel energy storage device 100 is not activated, both the first rotor 22 and the second rotor 32 are in a non-magnetically levitized state axially; when the flywheel energy storage device 100 is powered on and activated, both the first rotor 22 and the second rotor 32 are magnetically levitized axially within the housing 10. This reduces frictional losses in the flywheel energy storage device 100 and improves its efficiency.

[0035] Furthermore, the first stator 21 is fixedly connected to the housing 10, and at least a portion of the first rotor 22 is disposed inside the first stator 21 and radially clearance-fitted with the first stator 21. Thus, when the first motor assembly 20 is charging, the first stator 21 drives the first rotor 22 to rotate, converting electrical energy into kinetic energy. When the first motor assembly 20 is discharging, the first rotor 22 rotates, causing the first stator 21 to generate electricity, releasing kinetic energy as electrical energy.

[0036] Furthermore, the second stator 31 is fixedly connected to the housing 10, and at least a portion of the second rotor 32 is disposed inside the second stator 31 and radially clearance-fitted with the second stator 31. Thus, when the second motor assembly 30 is charging, the second stator 31 drives the second rotor 32 to rotate, converting electrical energy into kinetic energy. When the second motor assembly 30 is discharging, the second rotor 32 rotates, causing the second stator 31 to generate electricity, releasing kinetic energy as electrical energy.

[0037] Furthermore, by having the controller selectively synchronize the movement of the first rotor 22 of the first motor assembly 20 and the second rotor 32 of the second motor assembly 30, that is, the controller can control the first rotor 22 and the second rotor 32 to move synchronously or independently, the first motor assembly 20 can selectively discharge or charge, and the second motor assembly 30 can selectively discharge or charge. Moreover, the operation of the first motor assembly 20 and the second motor assembly 30 can be selectively synchronized or independent, thereby adapting to different operating states of the flywheel energy storage device 100 and improving the working performance of the flywheel energy storage device 100.

[0038] When the flywheel energy storage device 100 is in a short-term high-power cyclic charging and discharging working state, the charging and discharging of the first motor assembly 20 and the second motor assembly 30 can be controlled by differential control of the first motor assembly 20 and the second motor assembly 30 through a real-time control algorithm to balance the energy flow, reduce response time and cycle time, and improve service life.

[0039] Specifically, when the flywheel energy storage device 100 is not started, the first rotor 22 and the second rotor 32 are not synchronized.

[0040] After the flywheel energy storage device 100 is started, the controller controls the first rotor 22 and the second rotor 32 to levitate and control the first rotor 22 and the second rotor 32 to synchronize. The first motor assembly 20 and the second motor assembly 30 start working and begin the overall charging of the flywheel energy storage device 100 until the overall charging is completed.

[0041] After charging is complete, continuous cyclic charging and discharging will begin as needed.

[0042] First, the controller desynchronizes the first rotor 22 and the second rotor 32. At this point, the first motor assembly 20 and the second motor assembly 30 can be considered as two independent systems. The first motor assembly 20 begins to discharge, while the second motor assembly 30 continues to rotate at full speed and at a constant speed. When the first motor assembly 20 reaches the end of its discharge, the second motor assembly 30 receives the discharge signal and begins to discharge in place of the first motor assembly 20, while the first rotor 22 enters a low-speed standby zone to cool down and wait for acceleration.

[0043] After the second motor assembly 30 finishes discharging, the controller synchronizes the first rotor 22 and the second rotor 32, converting the remaining rotational speed of the second rotor 32 during discharge into the initial acceleration of the first rotor 22 during charging, causing the first rotor 22 to begin rotating. Once the first rotor 22 begins charging, the controller desynchronizes the synchronization of the first rotor 22 and the second rotor 32, and the second rotor 32 enters a low-speed idle zone to cool down and await acceleration. When the first motor assembly 20 finishes charging, the second motor assembly 30 begins charging.

[0044] After the second motor assembly 30 finishes charging, the controller again controls the first rotor 22 and the second rotor 32 to move synchronously, converting the speed of the first rotor 22 into the torque required for the second rotor 32 to reach full speed, thus driving the second rotor 32 to maintain full speed, while the first rotor 22 begins to decelerate and discharge. The previous workflow is repeated.

[0045] In this way, during cyclic charging and discharging, the switching process between charging and discharging can be completed simultaneously by the second motor assembly 30 and the first motor assembly 20. One switches from discharging to constant speed, and the other switches from constant speed to charging. The switching process between the two is regarded as the switching between discharging and charging. This can avoid the large torque generated during cyclic charging and discharging, as well as the overheating problem caused by large torque and high power, improve the ability to continuously cycle charge and discharge for a long time, and extend the service life of the flywheel energy storage device 100.

[0046] Furthermore, when one of the first motor assembly 20 and the second motor assembly 30 fails, the synchronous movement between the first rotor 22 and the second rotor 32 can be released, allowing the first motor assembly 20 and the second motor assembly 30 to work independently. This enables the other of the first motor assembly 20 and the second motor assembly 30, which has not failed, to work. This not only provides redundant protection for the flywheel energy storage device 100 and ensures system safety, but also guarantees capacity.

[0047] It should be noted that the first motor assembly 20 and the second motor assembly 30 share the housing 10. This not only provides the flywheel energy storage device 100 with a compact structure and reduces its size, but also reduces friction loss and improves the working efficiency of the flywheel energy storage device 100. Furthermore, the shared housing 10 can be used for heat dissipation, reducing the waste of unnecessary heat dissipation area.

[0048] Therefore, by setting up a first motor assembly 20 and a second motor assembly 30, and by having the controller control the first rotor 22 of the first motor assembly 20 and the second rotor 32 of the second motor assembly 30 to move synchronously or independently, not only can redundant protection of the flywheel energy storage device 100 be achieved, but also the large torque and overheating problems generated during cyclic charging and discharging can be avoided, thereby improving the ability to continuously cycle charge and discharge for a long time and enhancing the working performance of the flywheel energy storage device 100.

[0049] Furthermore, a first synchronizing element 223 is provided at the end of the first rotor 22 facing the second rotor 32, and a second synchronizing element 323 is provided at the end of the second rotor 32 facing the first rotor 22. The first synchronizing element 223 and the second synchronizing element 323 are adapted to realize the synchronous movement of the first rotor 22 and the second rotor 32.

[0050] Specifically, by setting a first synchronizing element 223 at the end of the first rotor 22 facing the second rotor 32 and setting a second synchronizing element 323 at the end of the second rotor 32 facing the first rotor 22, a synchronization system can be formed between the first synchronizing element 223 and the second synchronizing element 323. By controlling the synchronization system, the first rotor 22 and the second rotor 32 can move synchronously, and the first rotor 22 and the second rotor 32 can move independently, which makes the structure of the flywheel energy storage device 100 simpler and more reliable.

[0051] In some embodiments of the present invention, the first synchronization element 223 may include a plurality of permanent magnets, the second synchronization element 323 may include a plurality of permanent magnets, a magnetic attraction is formed between the first synchronization element 223 and the second synchronization element 323, the controller may control the first rotor 22 and the second rotor 32 to move closer in the vertical direction to control the first rotor 22 and the second rotor 32 to move synchronously, the controller may also control the first rotor 22 and the second rotor 32 to move further apart in the vertical direction to control the first rotor 22 and the second rotor 32 to move independently.

[0052] It is understandable that by including multiple permanent magnets in both the first synchronizing element 223 and the second synchronizing element 323, the magnitude of the magnetic attraction between them can be negatively correlated with the distance between them. By simply controlling the distance between the first synchronizing element 223 and the second synchronizing element 323, the magnitude of the magnetic force between them can be controlled, thus achieving synchronization adjustment between the first rotor 22 and the second rotor 32. This simplifies the structure of the flywheel energy storage device 100 and makes the selective synchronization between the first rotor 22 and the second rotor 32 simpler and more reliable.

[0053] Combination Figure 2 and Figure 3As shown, the first rotor 22 may include a first motor rotor 221 and a first rotor flywheel 222. The first motor rotor 221 and the first rotor flywheel 222 are coaxially arranged and interconnected. The first motor rotor 221 is disposed inside the first stator 21 and has a radial clearance fit with the first stator 21, so that power can be transmitted between the first motor rotor 221 and the first rotor flywheel 222. When the first motor assembly 20 is charging, the first stator 21 drives the first motor rotor 221 to rotate, which in turn drives the first rotor flywheel 222 to rotate, converting electrical energy into kinetic energy of the first rotor flywheel 222. When the first motor assembly 20 is discharging, the first rotor flywheel 222 drives the first motor rotor 221, causing the first stator 21 to generate electricity, releasing kinetic energy as electrical energy.

[0054] Furthermore, the second rotor 32 may include a second motor rotor 321 and a second rotor flywheel 322, which are coaxially arranged and interconnected. The second motor rotor 321 is disposed inside the second stator 31 and radially clearance-fitted with the second stator 31, allowing power to be transmitted between the second motor rotor 321 and the second rotor flywheel 322. When the second motor assembly 30 is charging, the second stator 31 drives the second motor rotor 321 to rotate, further driving the second rotor flywheel 322 to rotate, converting electrical energy into kinetic energy of the second rotor flywheel 322. When the second motor assembly 30 is discharging, the second rotor flywheel 322 drives the second motor rotor 321, causing the second stator 31 to generate electricity, releasing kinetic energy as electrical energy.

[0055] Furthermore, the first motor rotor 221 is located above the first rotor flywheel 222, and the second motor rotor 321 is located below the second rotor flywheel 322. That is, the first rotor flywheel 222 and the second rotor flywheel 322 are arranged opposite to each other in the vertical direction and are adjacent to each other. By providing a first synchronizing element 223 on the side of the first rotor flywheel 222 facing the second rotor flywheel 322, and providing a second synchronizing element 323 on the side of the second rotor flywheel 322 facing the first rotor flywheel 222, the first synchronizing element 223 and the second synchronizing element 323 can be arranged opposite to each other in the vertical direction and are adjacent to each other. This optimizes the structure and arrangement of the first motor assembly 20 and the second motor assembly 30, facilitates selective synchronous movement of the first rotor 22 and the second rotor 32 through the first synchronizing element 223 and the second synchronizing element 323, and simplifies the structure of the flywheel energy storage device 100.

[0056] Combination Figures 1-3As shown, the housing 10 may include an outer cover 11, a first end cap assembly 12, and a second end cap assembly 13. The outer cover 11 extends in the vertical direction, the first end cap assembly 12 is disposed at the upper end of the outer cover 11, and the second end cap assembly 13 is disposed at the lower end of the outer cover 11, thereby jointly defining the accommodating space, ensuring the vacuum environment of the accommodating space, and reducing the wind resistance of the first rotor 22 and the second rotor 32 at high speeds.

[0057] Combination Figure 2 and Figure 4 As shown, in the vertical direction, the outer cover 11 has a first axial magnetic levitation bearing 1111, an intermediate magnetic levitation assembly 1112, and a second axial magnetic levitation bearing 1121 arranged sequentially at intervals on the side wall facing the accommodating space. The intermediate magnetic levitation assembly 1112 includes a third axial magnetic levitation bearing and a fourth axial magnetic levitation bearing. The third axial magnetic levitation bearing is located above the fourth axial magnetic levitation bearing. In the vertical direction, the first rotor flywheel 222 is located between the first axial magnetic levitation bearing 1111 and the third axial magnetic levitation bearing, and the second rotor flywheel 322 is located between the second axial magnetic levitation bearing 1121 and the fourth axial magnetic levitation bearing.

[0058] With this configuration, the first axial magnetic levitation bearing 1111 and the third axial magnetic levitation bearing can form a magnetic levitation bearing assembly, located at the upper and lower ends of the first rotor flywheel 222, respectively. The first axial magnetic levitation bearing 1111 can apply axial magnetic force to the upper end of the first rotor flywheel 222, and the third axial magnetic levitation bearing can apply axial magnetic force to the lower end of the first rotor flywheel 222. This results in a more uniform force distribution on the first rotor flywheel 222 and even the first rotor 22, ensuring the axial levitation stability of the first rotor 22.

[0059] Furthermore, the second axial magnetic levitation bearing 1121 and the fourth axial magnetic levitation bearing can form a magnetic levitation bearing assembly, and are located at the lower end and upper end of the second rotor flywheel 322, respectively. The second axial magnetic levitation bearing 1121 can apply axial magnetic force to the lower end of the second rotor flywheel 322, and the fourth axial magnetic levitation bearing can apply axial magnetic force to the upper end of the second rotor flywheel 322. This allows for a more uniform force distribution on the second rotor flywheel 322 and even the second rotor 32, ensuring the axial levitation stability of the second rotor 32.

[0060] Furthermore, the outer cover 11 may include: a first outer cover 111 and a second outer cover 112, the second outer cover 112 being connected to the lower part of the first outer cover 111, a first axial magnetic levitation bearing 1111 being disposed on the side wall of the first outer cover 111 facing the receiving space, an intermediate magnetic levitation assembly 1112 being disposed on the side wall of the first outer cover 111 facing the receiving space, a second axial magnetic levitation bearing 1121 being disposed on the side wall of the second outer cover 112 facing the receiving space, a first motor assembly 20 and a second rotor flywheel 322 being disposed inside the first outer cover 111, and a second stator 31 and a second motor rotor 321 being disposed inside the second outer cover 112, which facilitates the assembly of the flywheel energy storage device 100.

[0061] Combination Figure 2 and Figure 4 As shown, the first end cap assembly 12 may include: a first end cap body 121 and a first radial magnetic levitation bearing 122. A first motor rotor 221 is at least partially located inside the first end cap body 121 and is radially clearance-fitted with the first end cap body 121. The first radial magnetic levitation bearing 122 is disposed on the side of the first end cap body 121 facing the first motor rotor 221. Furthermore, the intermediate magnetic levitation assembly 1112 may also include: a third radial magnetic levitation bearing. The first rotor flywheel 222 is at least partially disposed within the third radial magnetic levitation bearing and is radially spaced from the third radial magnetic levitation bearing.

[0062] With this configuration, the first radial magnetic levitation bearing 122 and the third radial magnetic levitation bearing can form a magnetic levitation bearing assembly, located at the upper and lower ends of the first rotor 22, respectively. The first radial magnetic levitation bearing 122 can apply radial magnetic force to the first motor rotor 221, and the third radial magnetic levitation bearing can apply radial magnetic force to the first rotor flywheel 222. This results in a more uniform force distribution on the first rotor 22, ensuring coaxial alignment between the first rotor 22 and the housing 10, preventing the first rotor 22 from tilting within the accommodating space, avoiding contact between the first rotor 22 and the first end cover body 121 or the housing 10, reducing frictional losses, and thus ensuring the radial levitation stability of the first rotor 22.

[0063] Furthermore, a first radial sensor is provided inside the first end cap body 121, and the intermediate magnetic levitation assembly 1112 also includes a third radial sensor. The first radial sensor and the third radial sensor are electrically connected to the controller, respectively.

[0064] Specifically, the first radial sensor can detect its radial distance from the first motor rotor 221, and the third radial sensor can detect its radial distance from the first rotor flywheel 222. By setting up the first and third radial sensors and electrically connecting them to the controller, when the flywheel energy storage device 100 is working, the controller can acquire the detection data from the first and third radial sensors and correspondingly control the magnetic force of the first and third radial magnetic levitation bearings 122 and 122. This real-time feedback control adjusts the electromagnetic force, making the controller's control of the first and third radial magnetic levitation bearings 122 and 122 more intelligent and reliable, thereby ensuring the stability and reliability of the radial levitation control of the first rotor 22.

[0065] Combination Figure 2 and Figure 4 As shown, the housing 10 may further include a second end cap assembly 13, which is disposed at the lower end of the outer cover 11. The second end cap assembly 13 may include a second end cap body 131 and a second radial magnetic levitation bearing 132. The second motor rotor 321 is at least partially located inside the second end cap body 131 and is radially clearance-fitted with the second end cap body 131. The second radial magnetic levitation bearing 132 is disposed on the side of the second end cap body 131 facing the second motor rotor 321. Furthermore, the intermediate magnetic levitation assembly 1112 may further include a fourth radial magnetic levitation bearing, in which the second rotor flywheel 322 is at least partially disposed, radially spaced from the fourth radial magnetic levitation bearing.

[0066] With this configuration, the second radial magnetic levitation bearing 132 and the fourth radial magnetic levitation bearing can form a magnetic levitation bearing assembly, located at the lower and upper ends of the second rotor 32, respectively. The second radial magnetic levitation bearing 132 can apply radial magnetic force to the second motor rotor 321, and the fourth radial magnetic levitation bearing can apply radial magnetic force to the second rotor flywheel 322. This results in a more uniform force distribution on the second rotor 32, ensuring coaxial alignment between the second rotor 32 and the housing 10, preventing contact between the second rotor 32 and the second end cover body 131 or the housing 10, reducing frictional losses, and thus ensuring the radial levitation stability of the second rotor 32.

[0067] Furthermore, a second radial sensor is provided inside the second end cap body 131, and the intermediate magnetic levitation assembly 1112 may also include a fourth radial sensor, wherein the second radial sensor and the fourth radial sensor are electrically connected to the controller respectively.

[0068] Specifically, the second radial sensor can detect its radial distance from the second motor rotor 321, and the fourth radial sensor can detect its radial distance from the second rotor flywheel 322. By setting up the second and fourth radial sensors and electrically connecting them to the controller, the controller can acquire the detection data from the second and fourth radial sensors when the flywheel energy storage device 100 is operating. It can then correspondingly control the magnetic force of the second and fourth radial magnetic levitation bearings 132 and 132, thereby providing real-time feedback control and adjusting the electromagnetic force. This makes the controller's control of the second and fourth radial magnetic levitation bearings 132 and 132 more intelligent and reliable, thus ensuring the stability and reliability of the radial levitation control of the second rotor 32.

[0069] In some embodiments of the present invention, a first protective bearing is further provided inside the first end cap body 121, and a second protective bearing is further provided inside the second end cap body 131.

[0070] This configuration serves two purposes. First, during normal operation of the flywheel energy storage device 100, the first protective bearing and the first rotor 22 are not in contact, and the second protective bearing and the second rotor 32 are not in contact, thus preventing increased frictional damage to the first rotor 22 and the second rotor 32. Second, when any of the magnetic levitation bearings fails due to power outage, control component malfunction, or accidental impact, the first protective bearing can act as a mechanical backup to promptly support the first rotor 22, and the second protective bearing can act as a mechanical backup to promptly support the second rotor 32, limiting the range of motion of the first rotor 22 and the second rotor 32. This prevents the first rotor 22 and the second rotor 32 from colliding, wearing down, or even exploding due to uncontrolled high-speed rotation, thereby improving the safety of the flywheel energy storage device 100.

[0071] The above can form a more complete flywheel energy storage device 100. When the flywheel energy storage device 100 is working, its specific working principle is as follows:

[0072] When the flywheel energy storage device 100 is not started, the second rotor 32 rests on the second end cover body 131, and the first rotor 22 is controlled to levitate by the third axial magnetic levitation bearing and the first axial magnetic levitation bearing 1111. At this time, the synchronization system is not working.

[0073] After the flywheel energy storage device 100 is started, the second rotor 32 is controlled to levitate by the second axial magnetic levitation bearing 1121 and the fourth axial magnetic levitation bearing. The synchronization system realizes magnetic field coupling, the first motor assembly 20 and the second motor assembly 30 start to work, driving the first rotor flywheel 222 and the second rotor flywheel 322 to start synchronous operation, and the flywheel energy storage device 100 starts to charge as a whole until the overall charging is completed.

[0074] After charging is complete, continuous cyclic charging and discharging will begin as needed.

[0075] First, the first axial magnetic levitation bearing 1111 controls the first rotor 22 to move upward, reducing magnetic field coupling. At this time, the first motor assembly 20 and the second motor assembly 30 can be regarded as two independent systems. The first motor assembly 20 begins to discharge, while the second motor assembly 30 continues to rotate at full speed. When the first motor assembly 20 reaches the end of its discharge, the second motor assembly 30 receives the discharge signal and begins to discharge in place of the first motor assembly 20, while the first rotor 22 enters a low-speed idle zone to cool down and wait for acceleration.

[0076] After the second motor assembly 30 finishes discharging, the first axial magnetic levitation bearing 1111 controls the first rotor 22 to move downwards, increasing magnetic field coupling. At this time, the first rotor 22 and the second rotor 32 rotate at almost the same speed. Utilizing the magnetic field coupling characteristics, the remaining speed of the second rotor 32 during discharge is converted into the initial acceleration of the first rotor 22 during charging, causing the first rotor 22 to begin rotating. After the first rotor 22 begins charging, the second axial magnetic levitation bearing 1121 controls the second rotor 32 to move downwards, reducing magnetic field coupling. At this time, the second rotor 32 enters a low-speed idle zone, cooling down and waiting to begin acceleration. After the first motor assembly 20 finishes charging, the second motor assembly 30 begins charging.

[0077] After the second motor assembly 30 finishes charging, the second axial magnetic levitation bearing 1121 controls the second rotor 32 to move upward, increasing magnetic field coupling. At this time, the first rotor 22 and the second rotor 32 rotate at almost the same speed. Utilizing the magnetic field coupling characteristics, the rotational speed of the first rotor 22 is converted into the torque required for the second rotor 32 to reach full speed, driving the second rotor 32 to maintain full speed. At the same time, the first rotor 22 begins to decelerate and discharge. The previous workflow is repeated.

[0078] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0079] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0080] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A flywheel energy storage device, characterized in that, include: A housing having an internal receiving space; A first motor assembly is disposed in the accommodating space and includes a first stator and a first rotor. The first stator is fixedly connected to the housing. At least a portion of the first rotor is disposed inside the first stator and is radially clearance-fitted with the first stator. When the flywheel energy storage device is powered on and started, the first rotor is magnetically levitated axially within the housing. A first synchronizing element is disposed at one end of the first rotor facing the second rotor. The first synchronizing element includes a plurality of permanent magnets. The second motor assembly is disposed in the accommodating space and spaced below the first motor assembly. The second motor assembly includes a second stator and a second rotor. The second stator is fixedly connected to the housing. At least a portion of the second rotor is disposed inside the second stator and is radially clearance-fitted with the second stator. When the flywheel energy storage device is powered on and started, the second rotor is magnetically levitated axially within the housing. A second synchronizing element is provided at one end of the second rotor facing the first rotor. The second synchronizing element includes a plurality of permanent magnets. A magnetic attraction force is formed between the first synchronizing element and the second synchronizing element. A controller that controls the first rotor and the second rotor to move closer together in the vertical direction, so as to control the first rotor and the second rotor to move synchronously.

2. The flywheel energy storage device according to claim 1, characterized in that, The first rotor includes: a first motor rotor and a first rotor flywheel, the first motor rotor and the first rotor flywheel are coaxially arranged and connected to each other, the first motor rotor is located above the first rotor flywheel, and the first motor rotor is disposed inside the first stator and is radially clearance-fitted with the first stator; The second rotor includes: a second motor rotor and a second rotor flywheel, the second motor rotor and the second rotor flywheel are coaxially arranged and connected to each other, the second motor rotor is located below the second rotor flywheel, and the second motor rotor is disposed inside the second stator and is radially clearance-fitted with the second stator; The first synchronizing element is provided on the side of the first rotor flywheel facing the second rotor flywheel, and the second synchronizing element is provided on the side of the second rotor flywheel facing the first rotor flywheel.

3. The flywheel energy storage device according to claim 2, characterized in that, The housing includes an outer cover that extends vertically. Along the vertical direction, a first axial magnetic levitation bearing, an intermediate magnetic levitation assembly, and a second axial magnetic levitation bearing are sequentially spaced along the sidewall of the outer cover facing the accommodating space. The first axial magnetic levitation bearing, the intermediate magnetic levitation assembly, and the second axial magnetic levitation bearing are electrically connected to the controller. The intermediate magnetic levitation assembly includes a third axial magnetic levitation bearing and a fourth axial magnetic levitation bearing. The third axial magnetic levitation bearing is located above the fourth axial magnetic levitation bearing. Vertically, a first rotor flywheel is located between the first and third axial magnetic levitation bearings, and a second rotor flywheel is located between the second and fourth axial magnetic levitation bearings.

4. The flywheel energy storage device according to claim 3, characterized in that, The outer cover includes: a first outer cover and a second outer cover, the second outer cover being connected below the first outer cover, the first axial magnetic levitation bearing being disposed on the side wall of the first outer cover facing the receiving space, the intermediate magnetic levitation assembly being disposed on the side wall of the first outer cover facing the receiving space, the second axial magnetic levitation bearing being disposed on the side wall of the second outer cover facing the receiving space, the first motor assembly and the second rotor flywheel being disposed inside the first outer cover, and the second stator and the second motor rotor being disposed inside the second outer cover.

5. The flywheel energy storage device according to claim 3, characterized in that, The housing also includes a first end cap assembly, which is disposed at the upper end of the outer cover. The first end cap assembly includes a first end cap body and a first radial magnetic levitation bearing. The first motor rotor is at least partially located inside the first end cap body and is in radial clearance fit with the first end cap body. The first radial magnetic levitation bearing is disposed on the side of the first end cap body facing the first motor rotor. The intermediate magnetic levitation assembly further includes a third radial magnetic levitation bearing, wherein the first rotor flywheel is at least partially disposed within the third radial magnetic levitation bearing and is radially spaced from the third radial magnetic levitation bearing.

6. The flywheel energy storage device according to claim 5, characterized in that, The first end cap body is provided with a first radial sensor, and the intermediate magnetic levitation assembly further includes a third radial sensor. The first radial sensor and the third radial sensor are respectively electrically connected to the controller.

7. The flywheel energy storage device according to claim 3, characterized in that, The housing also includes a second end cap assembly, which is disposed at the lower end of the outer cover. The second end cap assembly includes a second end cap body and a second radial magnetic levitation bearing. The second motor rotor is at least partially located inside the second end cap body and is radially clearance-fitted with the second end cap body. The second radial magnetic levitation bearing is disposed on the side of the second end cap body facing the second motor rotor. The intermediate magnetic levitation assembly further includes a fourth radial magnetic levitation bearing, wherein the second rotor flywheel is at least partially disposed within the fourth radial magnetic levitation bearing and is radially spaced from the fourth radial magnetic levitation bearing.

8. The flywheel energy storage device according to claim 7, characterized in that, The second end cap body is provided with a second radial sensor, and the intermediate magnetic levitation assembly further includes a fourth radial sensor. The second radial sensor and the fourth radial sensor are respectively electrically connected to the controller.

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