Flywheel energy storage device

Abstract

The invention relates to the technical field of flywheel energy storage, in particular to flywheel energy storage equipment which comprises a shell, a flywheel energy storage device and a flywheel energy storage device. The first motor assembly comprises a first stator and a first rotor, and when the flywheel energy storage equipment is powered on and started, the first rotor is magnetically suspended in the shell in the axial direction; the second motor assembly comprises a second stator and a second rotor, and when the flywheel energy storage equipment is powered on and started, the second rotor is magnetically suspended in the shell in the axial direction; and the controller controls the first rotor and the second rotor to move synchronously. Therefore, the first motor assembly and the second motor assembly are arranged, and the controller controls the first rotor and the second rotor to synchronously move or independently move, so that redundancy protection of the flywheel energy storage equipment can be realized, and large torque generated in the cyclic charging and discharging process can be avoided; and the over-temperature problem caused by large torque and high power is solved, and the long-time continuous cycle charging and discharging capability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flywheel energy storage, and more particularly to a flywheel energy storage device. Background Art

[0002] A flywheel energy storage device is a type of energy storage method that uses an electric motor to drive a flywheel to rotate at a high speed and then uses the flywheel to drive a generator to generate electricity when needed. It has the characteristics of high efficiency, long life, high safety, and environmental friendliness.

[0003] In the related art, the structural design of the flywheel energy storage device is not reasonable enough, and the torque is too large during startup and shutdown. When achieving the purpose of short-time high-power cyclic charge and discharge, it will have an excessive torque impact on the rotor, and at the same time, it will cause the stator and rotor of the motor to generate high temperatures, affecting the service life of the flywheel energy storage device. Summary of the Invention

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

[0005] The flywheel energy storage device according to an embodiment of the present invention includes: a housing, within which an accommodation space is formed; a first motor assembly disposed in the accommodation space and including: a first stator and a first rotor, the first stator being fixedly connected to the housing, at least a part of the first rotor being disposed inside the first stator and being in radial clearance fit with the first stator, when the flywheel energy storage device is powered on and started, the first rotor is magnetically levitated in the housing in the axial direction; a second motor assembly disposed in the accommodation 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 part of the second rotor being disposed inside the second stator and being in radial clearance fit with the second stator, when the flywheel energy storage device is powered on and started, the second rotor is magnetically levitated in the housing in the axial direction; a controller for controlling the synchronous movement of the first rotor and the second rotor.

[0006] Thus, by providing the first motor assembly and the second motor assembly, and enabling the controller to control the synchronous movement or independent movement of the first rotor and the second rotor, not only can redundant protection of the flywheel energy storage device be achieved, but also the large torque generated during the cyclic charge and discharge process, as well as the over-temperature problem caused by the large torque and high power, can be avoided, improving the ability of long-time continuous cyclic charge and discharge.

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

[0008] In some examples of the present invention, the first synchronizing member includes a plurality of permanent magnets, the second synchronizing member includes a plurality of permanent magnets, a magnetic attraction force is formed between the first synchronizing member and the second synchronizing member, and the controller controls the first rotor and the second rotor to approach in the up and down directions to control the synchronous movement of the first rotor and the second rotor.

[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 are coaxially arranged and connected to each other. The first motor rotor is located above the first rotor flywheel. The first motor rotor is arranged inside the first stator and is in radial clearance fit 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. The second motor rotor is arranged inside the second stator and is in radial clearance fit with the second stator; the first synchronizing member is provided on one side of the first rotor flywheel facing the second rotor flywheel, and the second synchronizing member is provided on one 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. The outer cover extends in the up and down directions. In the up and down directions, first axial magnetic suspension bearings, an intermediate magnetic suspension assembly, and second axial magnetic suspension bearings are sequentially and spaced apart on the side wall of the outer cover facing the accommodation space. The first axial magnetic suspension bearings, the intermediate magnetic suspension assembly, and the second axial magnetic suspension bearings are respectively electrically connected to the controller. The intermediate magnetic suspension assembly includes a third axial magnetic suspension bearing and a fourth axial magnetic suspension bearing. The third axial magnetic suspension bearing is located above the fourth axial magnetic suspension bearing. In the up and down directions, the first rotor flywheel is located between the first axial magnetic suspension bearing and the third axial magnetic suspension bearing, and the second rotor flywheel is located between the second axial magnetic suspension bearing and the fourth axial magnetic suspension 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 is connected below the first outer cover, the first axial magnetic levitation bearing is arranged on the side wall of the first outer cover facing the accommodation space, the intermediate magnetic levitation assembly is arranged on the side wall of the first outer cover facing the accommodation space, the second axial magnetic levitation bearing is arranged on the side wall of the second outer cover facing the accommodation space, the first motor assembly and the second rotor flywheel are arranged inside the first outer cover, and the second stator and the second motor rotor are arranged inside the second outer cover.

[0012] In some examples of the present invention, the housing further includes a first end cover assembly, the first end cover assembly is arranged at the upper end of the outer cover, and the first end cover assembly includes: a first end cover body and a first radial magnetic levitation bearing. At least part of the first motor rotor is located inside the first end cover body and is in clearance fit with the first end cover body in the radial direction. The first radial magnetic levitation bearing is arranged on the side of the first end cover body facing the first motor rotor; the intermediate magnetic levitation assembly further includes: a third radial magnetic levitation bearing. At least part of the first rotor flywheel is arranged inside 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 arranged inside the first end cover body, 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.

[0014] In some examples of the present invention, the housing further includes a second end cover assembly, the second end cover assembly is arranged at the lower end of the outer cover, and the second end cover assembly includes: a second end cover body and a second radial magnetic levitation bearing. At least part of the second motor rotor is located inside the second end cover body and is in clearance fit with the second end cover body in the radial direction. The second radial magnetic levitation bearing is arranged on the side of the second end cover body facing the second motor rotor; the intermediate magnetic levitation assembly further includes: a fourth radial magnetic levitation bearing. At least part of the second rotor flywheel is arranged inside 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 arranged inside the second end cover body, 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.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, will become apparent in part from the following description, or will be learned through the practice of the present invention. Brief Description of the Drawings

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein: Figure 1 is a schematic diagram of a flywheel energy storage device according to an embodiment of the present invention; Figure 2 is a cross-sectional view of the flywheel energy storage device according to an embodiment of the present invention along the A-A direction; Figure 3 is an exploded view of the flywheel energy storage device according to an embodiment of the present invention; Figure 4 is a partial schematic diagram of the flywheel energy storage device according to an embodiment of the present invention.

[0018] Reference Signs: 100, flywheel energy storage device; 10, housing; 11, outer cover; 111, first outer cover; 1111, first axial magnetic bearing; 1112, intermediate magnetic suspension assembly; 112, second outer cover; 1121, second axial magnetic bearing; 12, first end cover assembly; 121, first end cover body; 122, first radial magnetic bearing; 13, second end cover assembly; 131, second end cover body; 132, second radial magnetic bearing; 20, first motor assembly; 21, first stator; 22, first rotor; 221, first motor rotor; 222, first rotor flywheel; 223, first synchronizer; 30, second motor assembly; 31, second stator; 32, second rotor; 321, second motor rotor; 322, second rotor flywheel; 323, second synchronizer. Detailed Description of the Embodiments

[0019] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present invention will be described in detail below.

[0020] Reference will be made below to Figures 1 - 4 describe the flywheel energy storage device 100 according to an embodiment of the present invention.

[0021] In conjunction with 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.

[0022] Among them, a receiving space is formed inside the housing 10. The first motor assembly 20 is disposed in 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 part of the first rotor 22 is disposed inside the first stator 21 and is in a radial clearance fit with the first stator 21. The first rotor 22 is selectively magnetically levitated inside the housing 10 in the axial direction. The second motor assembly 30 is disposed in the receiving space and is 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 part of the second rotor 32 is disposed inside the second stator 31 and is in a radial clearance fit with the second stator 31. The second rotor 32 is selectively magnetically levitated inside the housing 10 in the axial direction. The controller controls the first rotor 22 and the second rotor 32 to selectively move synchronously. It can be understood that the axial direction is the same as the up-and-down direction, and the radial direction is the direction perpendicular to the axial direction.

[0023] Specifically, by forming a receiving space inside the housing 10 and the receiving space is in a vacuum environment, both the first motor assembly 20 and the second motor assembly 30 are disposed in the receiving space, which can reduce the wind resistance of the first rotor 22 and the second rotor 32 at high speeds. And, by selectively magnetically levitating the first rotor 22 inside the housing 10 in the axial direction and the second rotor 32 inside the housing 10 in the axial direction. Specifically, when the flywheel energy storage device 100 is not started, the first rotor 22 is in a non-magnetically levitated state in the axial direction, and the second rotor 32 is in a non-magnetically levitated state in the axial direction. When the flywheel energy storage device 100 is powered on and started, the first rotor 22 is magnetically levitated inside the housing 10 in the axial direction, and the second rotor 32 is magnetically levitated inside the housing 10 in the axial direction, which can reduce the frictional loss of the flywheel energy storage device 100 and improve the efficiency of the flywheel energy storage device 100.

[0024] Furthermore, the first stator 21 is fixedly connected to the housing 10. At least a part of the first rotor 22 is disposed inside the first stator 21 and is in a radial clearance fit with the first stator 21. When the first motor assembly 20 is charged, the first stator 21 drives the first rotor 22 to rotate, converting electrical energy into kinetic energy. When the first motor assembly 20 discharges, the first rotor 22 rotates, causing the first stator 21 to generate electricity and releasing the kinetic energy as electrical energy.

[0025] And, the second stator 31 is fixedly connected to the housing 10. At least a part of the second rotor 32 is disposed inside the second stator 31 and is in a radial clearance fit with the second stator 31. When the second motor assembly 30 is charged, the second stator 31 drives the second rotor 32 to rotate, converting electrical energy into kinetic energy. When the second motor assembly 30 discharges, the second rotor 32 rotates, causing the second stator 31 to generate electricity and releasing the kinetic energy as electrical energy.

[0026] Furthermore, by enabling the controller to control the first rotor 22 of the first motor assembly 20 and the second rotor 32 of the second motor assembly 30 to selectively move synchronously, that is: the controller can control the first rotor 22 and the second rotor 32 to move synchronously, or can control the first rotor 22 and the second rotor 32 to move independently. In this way, the first motor assembly 20 can be selectively discharged or charged, the second motor assembly 30 can be selectively discharged or charged, and the operations of the first motor assembly 20 and the second motor assembly 30 can be selectively synchronized or independent of each other, so as to adapt to different working states of the flywheel energy storage device 100 and improve the working performance of the flywheel energy storage device 100.

[0027] When the flywheel energy storage device 100 is in the working state of short-term high-power cyclic charge and discharge, differential control of the first motor assembly 20 and the second motor assembly 30 can be performed, and real-time control algorithms are used to control the charge and discharge of the first motor assembly 20 and the second motor assembly 30 to balance the energy flow, reduce the response time and the cycle time, and increase the service life.

[0028] Specifically, when the flywheel energy storage device 100 is not started, the first rotor 22 and the second rotor 32 are not synchronized.

[0029] After the flywheel energy storage device 100 is started, the controller controls the first rotor 22 and the second rotor 32 to levitate and controls the first rotor 22 and the second rotor 32 to be synchronized. The first motor assembly 20 and the second motor assembly 30 start to operate, and the overall charging of the flywheel energy storage device 100 begins until the overall charging is completed.

[0030] After the charging is completed, continuous cyclic charge and discharge operations are started according to the demand.

[0031] First, the controller releases the synchronization of the first rotor 22 and the second rotor 32. 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 starts to discharge, and the second motor assembly 30 still maintains full speed and rotates at a constant speed. When the first motor assembly 20 reaches the end stage of discharge, the second motor assembly 30 receives the discharge signal and replaces the first motor assembly 20 to start discharging, while the first rotor 22 enters the low-speed standby area to cool down and wait to start accelerating.

[0032] After the discharge of the second motor assembly 30 ends, the controller controls the synchronous movement of the first rotor 22 and the second rotor 32, converts the remaining rotational speed of the second rotor 32 during discharge into the initial acceleration for charging the first rotor 22, and drives the first rotor 22 to start rotating. After the first rotor 22 starts charging, the controller releases the synchronous movement of the first rotor 22 and the second rotor 32, and the second rotor 32 enters the low-speed standby area to cool down and dissipate heat waiting to start accelerating. When the first motor assembly 20 finishes charging, the second motor assembly 30 starts charging.

[0033] After the second motor assembly 30 finishes charging, then, the controller controls the synchronous movement of the first rotor 22 and the second rotor 32 again, converts the rotational speed of the first rotor 22 into the torque requirement for the second rotor 32 to reach full speed, drives the second rotor 32 to maintain full speed, and at the same time the first rotor 22 starts to decelerate and discharge. Repeat the previous work process.

[0034] In this way, during cyclic charge and discharge, the switching process between charge and discharge can be completed simultaneously by the second motor assembly 30 and the first motor assembly 20. One changes from discharge to uniform speed, and the other changes from uniform speed to charge. The action switching process between the two is regarded as the switching between discharge and charge, so that the large torque generated during cyclic charge and discharge, as well as the over-temperature problem caused by large torque and high power, can be avoided, the ability of long-time continuous cyclic charge and discharge can be improved, and the service life of the flywheel energy storage device 100 can be extended.

[0035] Moreover, 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, so that the first motor assembly 20 and the second motor assembly 30 work independently. Thus, the other one of the first motor assembly 20 and the second motor assembly 30 that does not fail can work, which can not only provide redundant protection for the flywheel energy storage device 100, ensure system safety, but also guarantee the capacity.

[0036] It should be noted that the first motor assembly 20 and the second motor assembly 30 share the housing 10. This can not only provide the structural compactness of the flywheel energy storage device 100, reduce the volume, but also reduce the frictional loss, improve the working efficiency of the flywheel energy storage device 100, and can also share the housing 10 for heat dissipation, reducing the waste of unnecessary heat dissipation area.

[0037] Therefore, by setting the first motor assembly 20 and the second motor assembly 30, and enabling the controller to control the synchronous movement or independent movement of the first rotor 22 of the first motor assembly 20 and the second rotor 32 of the second motor assembly 30, not only can redundant protection for the flywheel energy storage device 100 be achieved, but also the large torque generated during cyclic charge and discharge, as well as the over-temperature problem, can be avoided, the ability of long-time continuous cyclic charge and discharge can be improved, and the working performance of the flywheel energy storage device 100 can be enhanced.

[0038] Further, a first synchronizing member 223 is provided at one end of the first rotor 22 facing the second rotor 32, and a second synchronizing member 323 is provided at one end of the second rotor 32 facing the first rotor 22. The first synchronizing member 223 and the second synchronizing member 323 are adapted to achieve synchronous movement of the first rotor 22 and the second rotor 32.

[0039] Specifically, by providing the first synchronizing member 223 at one end of the first rotor 22 facing the second rotor 32 and the second synchronizing member 323 at one end of the second rotor 32 facing the first rotor 22, a synchronization system can be formed between the first synchronizing member 223 and the second synchronizing member 323. By only controlling the synchronization system, synchronous movement of the first rotor 22 and the second rotor 32 can be achieved, and independent movement of the first rotor 22 and the second rotor 32 can be achieved, making the structure of the flywheel energy storage device 100 simpler and more reliable.

[0040] In some embodiments of the present invention, the first synchronizing member 223 may include a plurality of permanent magnets, the second synchronizing member 323 may include a plurality of permanent magnets, a magnetic attraction force is formed between the first synchronizing member 223 and the second synchronizing member 323, and the controller can control the first rotor 22 and the second rotor 32 to approach in the up and down directions to control the synchronous movement of the first rotor 22 and the second rotor 32. The controller can also control the first rotor 22 and the second rotor 32 to move away from each other in the up and down directions to control the independent movement of the first rotor 22 and the second rotor 32.

[0041] It can be understood that by making the first synchronizing member 223 include a plurality of permanent magnets and the second synchronizing member 323 include a plurality of permanent magnets, the magnitude of the magnetic attraction force between the first synchronizing member 223 and the second synchronizing member 323 can be negatively correlated with the distance between the first synchronizing member 223 and the second synchronizing member 323. By only controlling the distance between the first synchronizing member 223 and the second synchronizing member 323, the magnitude of the magnetic force between the first synchronizing member 223 and the second synchronizing member 323 can be controlled, and the synchronization between the first rotor 22 and the second rotor 32 can be adjusted, so that the structure of the flywheel energy storage device 100 can be made simpler, and the realization of selective synchronization between the first rotor 22 and the second rotor 32 can be made simpler and more reliable.

[0042] Combined with 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 connected to each other. The first motor rotor 221 is arranged inside the first stator 21 and is in 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 charged, the first stator 21 drives the first motor rotor 221 to rotate, and further drives the first rotor flywheel 222 to rotate, converting electrical energy into the kinetic energy of the first rotor flywheel 222. When the first motor assembly 20 discharges, the first rotor flywheel 222 drives the first motor rotor 221, causing the first stator 21 to generate electricity and releasing the kinetic energy as electrical energy.

[0043] And, the second rotor 32 may include: a second motor rotor 321 and a second rotor flywheel 322. The second motor rotor 321 and the second rotor flywheel 322 are coaxially arranged and connected to each other. The second motor rotor 321 is arranged inside the second stator 31 and is in radial clearance fit with the second stator 31, so that power can be transmitted between the second motor rotor 321 and the second rotor flywheel 322. When the second motor assembly 30 is charged, the second stator 31 drives the second motor rotor 321 to rotate, and further drives the second rotor flywheel 322 to rotate, converting electrical energy into the kinetic energy of the second rotor flywheel 322. When the second motor assembly 30 discharges, the second rotor flywheel 322 drives the second motor rotor 321, causing the second stator 31 to generate electricity and releasing the kinetic energy as electrical energy.

[0044] 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 oppositely arranged in the vertical direction and are adjacently arranged. By providing a first synchronizing member 223 on the side of the first rotor flywheel 222 facing the second rotor flywheel 322, and a second synchronizing member 323 on the side of the second rotor flywheel 322 facing the first rotor flywheel 222, the first synchronizing member 223 and the second synchronizing member 323 can be oppositely arranged in the vertical direction and adjacently arranged, thereby optimizing the structure and installation position of the first motor assembly 20 and the second motor assembly 30, facilitating the selective synchronous movement of the first rotor 22 and the second rotor 32 through the first synchronizing member 223 and the second synchronizing member 323, and making the structure of the flywheel energy storage device 100 simpler.

[0045] Combined with Figures 1 - 3As shown, the housing 10 may include a housing 11, a first end cap assembly 12, and a second end cap assembly 13. The housing 11 extends in the up and down direction. The first end cap assembly 12 is disposed at the upper end of the housing 11, and the second end cap assembly 13 is disposed at the lower end of the housing 11, so as to jointly define an accommodation space, ensure the vacuum environment of the accommodation space, and reduce the wind resistance of the first rotor 22 and the second rotor 32 at high speeds.

[0046] Combined with Figure 2 and Figure 4 As shown, in the up and down direction, the side wall of the housing 11 facing the accommodation space is sequentially and spacedly provided with a first axial magnetic suspension bearing 1111, an intermediate magnetic suspension assembly 1112, and a second axial magnetic suspension bearing 1121. The intermediate magnetic suspension assembly 1112 includes a third axial magnetic suspension bearing and a fourth axial magnetic suspension bearing. The third axial magnetic suspension bearing is located above the fourth axial magnetic suspension bearing. In the up and down direction, the first rotor flywheel 222 is located between the first axial magnetic suspension bearing 1111 and the third axial magnetic suspension bearing, and the second rotor flywheel 322 is located between the second axial magnetic suspension bearing 1121 and the fourth axial magnetic suspension bearing.

[0047] With such an arrangement, the first axial magnetic suspension bearing 1111 and the third axial magnetic suspension bearing can form a magnetic suspension bearing group and are respectively located at the upper end and the lower end of the first rotor flywheel 222. Among them, the first axial magnetic suspension bearing 1111 can apply an axial magnetic force to the upper end of the first rotor flywheel 222, and the third axial magnetic suspension bearing can apply an axial magnetic force to the lower end of the first rotor flywheel 222, so that the force distribution of the first rotor flywheel 222 and even the first rotor 22 can be more uniform, and the axial suspension stability of the first rotor 22 can be ensured.

[0048] In addition, the second axial magnetic suspension bearing 1121 and the fourth axial magnetic suspension bearing can form a magnetic suspension bearing group and are respectively located at the lower end and the upper end of the second rotor flywheel 322. Among them, the second axial magnetic suspension bearing 1121 can apply an axial magnetic force to the lower end of the second rotor flywheel 322, and the fourth axial magnetic suspension bearing can apply an axial magnetic force to the upper end of the second rotor flywheel 322, so that the force distribution of the second rotor flywheel 322 and even the second rotor 32 can be more uniform, and the axial suspension stability of the second rotor 32 can be ensured.

[0049] Further, the outer cover 11 may include: a first outer cover 111 and a second outer cover 112. The second outer cover 112 is connected to the lower part of the first outer cover 111. The first axial magnetic levitation bearing 1111 is arranged on the side wall of the first outer cover 111 facing the accommodation space. The intermediate magnetic levitation assembly 1112 is arranged on the side wall of the first outer cover 111 facing the accommodation space. The second axial magnetic levitation bearing 1121 is arranged on the side wall of the second outer cover 112 facing the accommodation space. The first motor assembly 20 and the second rotor flywheel 322 are arranged inside the first outer cover 111. The second stator 31 and the second motor rotor 321 are arranged inside the second outer cover 112. This facilitates the assembly of the flywheel energy storage device 100.

[0050] Combined Figure 2 with Figure 4 as shown, the first end cover assembly 12 may include: a first end cover body 121 and a first radial magnetic levitation bearing 122. The first motor rotor 221 is at least partially located inside the first end cover body 121 and is in clearance fit with the first end cover body 121 in the radial direction. The first radial magnetic levitation bearing 122 is arranged on one side of the first end cover body 121 facing the first motor rotor 221. And, the intermediate magnetic levitation assembly 1112 may further include: a third radial magnetic levitation bearing. The first rotor flywheel 222 is at least partially arranged inside the third radial magnetic levitation bearing and is radially spaced from the third radial magnetic levitation bearing.

[0051] With such an arrangement, the first radial magnetic levitation bearing 122 and the third radial magnetic levitation bearing can form a magnetic levitation bearing group and are respectively located at the upper end and the lower end of the first rotor 22. Among them, the first radial magnetic levitation bearing 122 can apply a radial magnetic force to the first motor rotor 221, and the third radial magnetic levitation bearing can apply a radial magnetic force to the first rotor flywheel 222, so that the force distribution of the first rotor 22 can be made more uniform, the coaxial setting of the first rotor 22 and the housing 10 can be ensured, the inclination of the first rotor 22 in the accommodation space can be avoided, the contact between the first rotor 22 and the first end cover body 121 or the housing 10 can be avoided, the friction loss can be reduced, and further the suspension stability of the first rotor 22 in the radial direction can be ensured.

[0052] Further, a first radial sensor is arranged inside the first end cover body 121. The intermediate magnetic levitation assembly 1112 further includes: a third radial sensor. The first radial sensor and the third radial sensor are respectively electrically connected to the controller.

[0053] 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 the first radial sensor and the third radial sensor, and electrically connecting the first radial sensor and the third radial sensor to the controller respectively, when the flywheel energy storage device 100 is operating, the controller can obtain the detection data of the first radial sensor and the third radial sensor, and correspondingly control the magnetic forces of the first radial magnetic levitation bearing 122 and the third radial magnetic levitation bearing, so as to adjust the electromagnetic force in real-time feedback control, which can make the control of the first radial magnetic levitation bearing 122 and the third radial magnetic levitation bearing by the controller more intelligent and reliable, and further ensure the stability and reliability of the radial suspension control of the first rotor 22.

[0054] Combined Figure 2 with Figure 4 As shown, the housing 10 may further include a second end cover assembly 13. The second end cover assembly 13 is disposed at the lower end of the outer cover 11. The second end cover assembly 13 may include: a second end cover body 131 and a second radial magnetic levitation bearing 132. At least a part of the second motor rotor 321 is located inside the second end cover body 131 and is in clearance fit with the second end cover body 131 in the radial direction. The second radial magnetic levitation bearing 132 is disposed on the side of the second end cover body 131 facing the second motor rotor 321. Moreover, the intermediate magnetic levitation assembly 1112 may further include: a fourth radial magnetic levitation bearing. At least a part of the second rotor flywheel 322 is disposed inside the fourth radial magnetic levitation bearing and is radially spaced from the fourth radial magnetic levitation bearing.

[0055] With such a setting, the second radial magnetic levitation bearing 132 and the fourth radial magnetic levitation bearing can form a magnetic levitation bearing group, and are respectively located at the lower end and the upper end of the second rotor 32. Among them, the second radial magnetic levitation bearing 132 can apply a radial magnetic force to the second motor rotor 321, and the fourth radial magnetic levitation bearing can apply a radial magnetic force to the second rotor flywheel 322, so that the force distribution of the second rotor 32 can be more uniform, the coaxial setting of the second rotor 32 and the housing 10 can be ensured, contact between the second rotor 32 and the second end cover body 131 or the housing 10 can be avoided, frictional losses can be reduced, and further the radial suspension stability of the second rotor 32 can be ensured.

[0056] Furthermore, a second radial sensor is disposed inside the second end cover body 131. The intermediate magnetic levitation assembly 1112 may further include: a fourth radial sensor. The second radial sensor and the fourth radial sensor are respectively electrically connected to the controller.

[0057] 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 the second radial sensor and the fourth radial sensor, and electrically connecting the second radial sensor and the fourth radial sensor to the controller respectively, when the flywheel energy storage device 100 works, the controller can obtain the detection data of the second radial sensor and the fourth radial sensor, and correspondingly control the magnetic forces of the second radial magnetic suspension bearing 132 and the fourth radial magnetic suspension bearing, so as to adjust the electromagnetic force in real-time feedback control, which can make the control of the second radial magnetic suspension bearing 132 and the fourth radial magnetic suspension bearing by the controller more intelligent and reliable, and further ensure the stability and reliability of the radial suspension control of the second rotor 32.

[0058] In some embodiments of the present invention, a first protective bearing is further provided in the first end cover body 121, and a second protective bearing is further provided in the second end cover body 131.

[0059] With such a setting, on the one hand, when the flywheel energy storage device 100 is working normally, the first protective bearing is not in contact with the first rotor 22, and the second protective bearing is not in contact with the second rotor 32, avoiding an increase in frictional damage to the first rotor 22 and the second rotor 32. On the other hand, when each magnetic suspension bearing fails due to power interruption, control component failure or accidental impact, the first protective bearing can support the first rotor 22 in time as a mechanical backup, and the second protective bearing can support the second rotor 32 in time as a mechanical backup, restricting the movement ranges of the first rotor 22 and the second rotor 32, preventing the first rotor 22 and the second rotor 32 from colliding, wearing or even exploding due to out-of-control high-speed rotation, and improving the safety of the flywheel energy storage device 100.

[0060] The above can form a more complete flywheel energy storage device 100. When the flywheel energy storage device 100 works, its specific working principle can be as follows: 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 suspension bearing and the first axial magnetic suspension bearing 1111. At this time, the synchronization system is not working.

[0061] After the flywheel energy storage device 100 is started, the second rotor 32 is levitated by relying on the second axial magnetic suspension bearing 1121 and the fourth axial magnetic suspension bearing, the synchronization system realizes magnetic field coupling, and 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 starting the overall charging of the flywheel energy storage device 100 until the overall charging is completed.

[0062] After the charging is completed, continuous cyclic charge and discharge behaviors are started according to requirements.

[0063] 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 starts to discharge, and at this time, the second motor assembly 30 still maintains full-speed rotation. When the first motor assembly 20 reaches the end of the discharge period, the second motor assembly 30 receives the discharge signal and replaces the first motor assembly 20 to start discharging, while the first rotor 22 enters the low-speed standby area to cool down and wait to start accelerating.

[0064] After the second motor assembly 30 finishes discharging, the first axial magnetic levitation bearing 1111 controls the first rotor 22 to move downward, increasing magnetic field coupling. At this time, the rotational speeds of the first rotor 22 and the second rotor 32 are almost the same. Using the magnetic field coupling characteristic, the remaining rotational speed of the second rotor 32 during discharge is converted into the initial acceleration for charging the first rotor 22, driving the first rotor 22 to start rotating. After the first rotor 22 starts charging, the second axial magnetic levitation bearing 1121 controls the second rotor 32 to move downward, reducing magnetic field coupling. At this time, the second rotor 32 enters the low-speed standby area to cool down and wait to start accelerating. After the first motor assembly 20 finishes charging, the second motor assembly 30 starts charging.

[0065] 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 rotational speeds of the first rotor 22 and the second rotor 32 are almost the same. Using the magnetic field coupling characteristic, the rotational speed of the first rotor 22 is converted into the torque requirement 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 starts to decelerate and discharge. Repeat the previous work process.

[0066] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0067] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0068] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A flywheel energy storage device, characterized in that, Comprising: A housing, an accommodation space is formed inside the housing; A first motor assembly, the first motor assembly is arranged in the accommodation space and includes: a first stator and a first rotor, the first stator is fixedly connected to the housing, at least part of the first rotor is arranged inside the first stator and is in radial clearance fit with the first stator, when the flywheel energy storage device is powered on and started, the first rotor is magnetically levitated in the housing in the axial direction; A second motor assembly, the second motor assembly is arranged in the accommodation space and is 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 part of the second rotor is arranged inside the second stator and is in radial clearance fit with the second stator, when the flywheel energy storage device is powered on and started, the second rotor is magnetically levitated in the housing in the axial direction; A controller, the controller controls the synchronous movement of the first rotor and the second rotor.

2. The flywheel energy storage device according to claim 1, wherein One end of the first rotor facing the second rotor is provided with a first synchronizing member, one end of the second rotor facing the first rotor is provided with a second synchronizing member, and the first synchronizing member and the second synchronizing member are adapted to realize the synchronous movement of the first rotor and the second rotor.

3. The flywheel energy storage device according to claim 2, characterized in that, The first synchronizing member includes a plurality of permanent magnets, the second synchronizing member includes a plurality of permanent magnets, a magnetic attraction force is formed between the first synchronizing member and the second synchronizing member, and the controller controls the first rotor and the second rotor to approach in the up and down directions to control the synchronous movement of the first rotor and the second rotor.

4. The flywheel energy storage device according to claim 2, wherein, 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 arranged inside the first stator and is in radial clearance fit 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 arranged inside the second stator and is in radial clearance fit with the second stator; The first synchronizing member is arranged on one side of the first rotor flywheel facing the second rotor flywheel, and the second synchronizing member is arranged on one side of the second rotor flywheel facing the first rotor flywheel.

5. The flywheel energy storage device according to claim 4, characterized in that, The housing includes a housing cover which extends in the vertical direction. In the vertical direction, on the side wall of the housing cover facing the accommodation space, a first axial magnetic levitation bearing, an intermediate magnetic levitation assembly, and a second axial magnetic levitation bearing are sequentially arranged at intervals. The first axial magnetic levitation bearing, the intermediate magnetic levitation assembly, and the second axial magnetic levitation bearing are respectively 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, the first rotor flywheel is located between the first axial magnetic levitation bearing and the third axial magnetic levitation bearing, and the second rotor flywheel is located between the second axial magnetic levitation bearing and the fourth axial magnetic levitation bearing.

6. The flywheel energy storage device according to claim 5, wherein, The housing cover includes: a first housing cover and a second housing cover. The second housing cover is connected below the first housing cover. The first axial magnetic levitation bearing is arranged on the side wall of the first housing cover facing the accommodation space. The intermediate magnetic levitation assembly is arranged on the side wall of the first housing cover facing the accommodation space. The second axial magnetic levitation bearing is arranged on the side wall of the second housing cover facing the accommodation space. The first motor assembly and the second rotor flywheel are arranged inside the first housing cover, and the second stator and the second motor rotor are arranged inside the second housing cover.

7. The flywheel energy storage device according to claim 5, wherein, The housing further includes a first end cover assembly which is arranged at the upper end of the housing cover. The first end cover assembly includes: a first end cover body and a first radial magnetic levitation bearing. At least part of the first motor rotor is located inside the first end cover body and is in clearance fit with the first end cover body in the radial direction. The first radial magnetic levitation bearing is arranged on one side of the first end cover body facing the first motor rotor. The intermediate magnetic levitation assembly further includes: a third radial magnetic levitation bearing. At least part of the first rotor flywheel is arranged inside the third radial magnetic levitation bearing and is radially spaced from the third radial magnetic levitation bearing.

8. The flywheel energy storage device according to claim 7, characterized in that, A first radial sensor is arranged inside the first end cover body. 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.

9. The flywheel energy storage device according to claim 5, wherein The housing further includes a second end cover assembly which is arranged at the lower end of the housing cover. The second end cover assembly includes: a second end cover body and a second radial magnetic levitation bearing. At least part of the second motor rotor is located inside the second end cover body and is in clearance fit with the second end cover body in the radial direction. The second radial magnetic levitation bearing is arranged on one side of the second end cover body facing the second motor rotor. The intermediate magnetic levitation assembly further includes: a fourth radial magnetic levitation bearing. At least part of the second rotor flywheel is arranged inside the fourth radial magnetic levitation bearing and is radially spaced from the fourth radial magnetic levitation bearing.

10. The flywheel energy storage device according to claim 9, characterized in that, A second radial sensor is disposed inside the second end cover body. 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.

Images