A flywheel energy storage motor motor eddy current brake device and a flywheel energy storage motor

Abstract

The application discloses a flywheel energy storage motor motor eddy current brake device and a flywheel energy storage motor, and belongs to the technical field of flywheel energy storage. The motor eddy current brake device comprises a machine shell, an upper end cover, a lower end cover, a flywheel and a brake module. The brake module comprises ferromagnetic blocks and excitation windings, the excitation windings are wound on the ferromagnetic blocks, or the excitation windings are arranged between the ferromagnetic blocks. The ferromagnetic blocks are uniformly arranged along the circumference of the flywheel, and there is a gap between adjacent ferromagnetic blocks or on each ferromagnetic block. The inner surface of each ferromagnetic block and the outer surface of the flywheel form an air gap, and the outer surface of each ferromagnetic block is in contact with the inner surface of the machine shell. The application further provides a flywheel energy storage motor comprising the motor eddy current brake device. The motor eddy current brake device can ensure emergency braking of the flywheel when a sudden situation occurs, improve the safety of system operation, and is suitable for various metal flywheel energy storage motors.

Description

Technical Field

[0001] This invention belongs to the field of flywheel energy storage technology, and more specifically, relates to an eddy current braking device for a flywheel energy storage motor and a flywheel energy storage motor. Background Technology

[0002] Flywheel energy storage technology, as a new type of energy storage technology, has advantages such as being pollution-free, having a fast charging and discharging response speed, and a long lifespan. It has been widely used in fields such as power grid peak shaving and frequency regulation, uninterruptible power supplies, and subway braking energy recovery.

[0003] The braking system is crucial for the safe operation of flywheel energy storage systems. As flywheels move towards higher speed ranges, the design of braking systems for high-speed flywheel rotors becomes particularly important. Friction braking is a commonly used braking method, but it has significant drawbacks under high-speed flywheel operation conditions, such as rapid wear and high noise. Furthermore, the braking force of this method is difficult to adjust, the response speed is slow, and the reliability is low. Summary of the Invention

[0004] In view of the shortcomings of the existing technology and the need for improvement, the present invention provides an eddy current braking device for a flywheel energy storage motor and a flywheel energy storage motor, the purpose of which is to provide a non-contact braking method for the flywheel energy storage motor and improve the reliability of braking.

[0005] To achieve the above objectives, according to one aspect of the present invention, a flywheel energy storage motor eddy current braking device is provided, comprising: a housing, an upper end cover, a lower end cover, a flywheel, and a braking module;

[0006] The housing is fixed between the upper end cover and the lower end cover, and together with the upper end cover and the lower end cover, they form a vacuum cavity. The flywheel is disposed in the vacuum cavity and is driven to rotate by an energy storage motor disposed above the flywheel.

[0007] The braking module includes ferromagnetic blocks and excitation windings. The excitation windings are wound around the ferromagnetic blocks or arranged between the ferromagnetic blocks. The ferromagnetic blocks are evenly arranged along the circumference of the flywheel, and there are gaps between adjacent ferromagnetic blocks or gaps on each ferromagnetic block.

[0008] The inner surface of each of the ferromagnetic blocks forms an air gap with the outer surface of the flywheel, and the outer surface of each of the ferromagnetic blocks is in contact with the inner surface of the housing.

[0009] Furthermore, the braking module includes an E-shaped ferromagnetic block and a first concentrated excitation winding;

[0010] The E-shaped ferromagnetic block includes teeth and a yoke. The inner arc surface of the teeth forms an air gap with the outer surface of the flywheel, and the outer arc surface of the yoke contacts the inner surface of the housing.

[0011] The first concentrated excitation winding is wound around the middle tooth of the E-shaped ferromagnetic block along the axial direction of the tooth.

[0012] Furthermore, the braking module includes a C-shaped ferromagnetic block and a second concentrated excitation winding;

[0013] A groove is provided in the center of the circumference of the C-shaped ferromagnetic block, and the second concentrated excitation winding is wound around the C-shaped ferromagnetic block along the circumference of the groove.

[0014] Furthermore, it also includes a magnetic shielding block disposed on the outer side of each of the C-shaped ferromagnetic blocks, the outer side of the magnetic shielding block being fixed to the inner surface of the housing, and the inner side of each of the C-shaped ferromagnetic blocks forming an air gap with the outer surface of the flywheel.

[0015] Furthermore, the braking module includes an arc-shaped upper ferromagnetic block, an arc-shaped lower ferromagnetic block, and a ring-shaped excitation winding;

[0016] The annular excitation winding is disposed between the upper arc-shaped ferromagnetic block and the lower arc-shaped ferromagnetic block, and surrounds the outside of the flywheel with an air gap between it and the flywheel;

[0017] The upper and lower arc-shaped ferromagnetic blocks are aligned along the flywheel axis.

[0018] Furthermore, the braking module includes an arc-shaped upper ferromagnetic block, an arc-shaped lower ferromagnetic block, and a ring-shaped excitation winding;

[0019] The annular excitation winding is disposed between the upper arc-shaped ferromagnetic block and the lower arc-shaped ferromagnetic block, and surrounds the outside of the flywheel with an air gap between it and the flywheel;

[0020] The upper and lower arc-shaped ferromagnetic blocks are staggered along the flywheel axis.

[0021] Furthermore, the braking module includes a right-angled upper ferromagnetic block, a right-angled lower ferromagnetic block, and a ring-shaped excitation winding;

[0022] The annular excitation winding is disposed between the right-angled upper ferromagnetic block and the right-angled lower ferromagnetic block, and surrounds the outside of the flywheel with an air gap between it and the flywheel;

[0023] The right-angled upper ferromagnetic block and the right-angled lower ferromagnetic block are staggered along the flywheel axis, and the right-angled upper ferromagnetic block and the right-angled lower ferromagnetic block form a claw pole structure.

[0024] Furthermore, a toothed groove is formed along the axial direction on the inner surface of the ferromagnetic block.

[0025] According to a second aspect of the present invention, a flywheel energy storage motor is provided, comprising a high-speed motor, a motor shaft, and an eddy current braking device; the high-speed motor is disposed above the flywheel, and the upper end face of the flywheel is connected to the motor shaft;

[0026] The eddy current braking device is any one of the eddy current braking devices described in the first aspect.

[0027] Furthermore, it also includes a flange and a screw located at the lower end of the motor shaft;

[0028] The flywheel has an annular groove on its upper end face. The flange is embedded in the groove and is installed with an interference fit to the central boss of the flywheel. The flange is axially connected to the upper end face of the flywheel through the screw.

[0029] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0030] (1) The eddy current braking device for the flywheel energy storage motor designed in this invention uses a braking module that works in conjunction with the flywheel and the housing. The excitation winding is wound around a ferromagnetic block, or the excitation winding is placed between the ferromagnetic blocks. The inner surface of each ferromagnetic block forms an air gap with the outer surface of the flywheel, and the outer surface of each ferromagnetic block contacts the inner surface of the housing. The ferromagnetic blocks are evenly distributed along the circumference of the flywheel, and the magnetic field at different positions is different. The air gap magnetic field is larger at the position corresponding to the ferromagnetic block, and smaller at the position where there is no ferromagnetic block. After a DC excitation current is passed through the excitation winding, an excitation magnetic field is generated in the air gap. The magnetic field at the same position of the flywheel continuously alternates, thereby generating eddy currents. The eddy current magnetic field and the excitation magnetic field interact to generate a braking torque opposite to the direction of flywheel rotation, thus achieving emergency braking of the flywheel. This invention is the first to realize the use of eddy current braking in a flywheel energy storage system, and the required braking torque can be adjusted by adjusting the number of ferromagnetic blocks according to the amount of energy stored in the flywheel energy storage system. This eddy current braking method results in fast braking speed, high reliability, and is a non-contact braking method, eliminating the drawbacks of rapid wear and high noise levels associated with high-speed flywheel operation.

[0031] (2) When the braking module adopts an E-shaped ferromagnetic block and a first concentrated excitation winding, the first concentrated excitation winding is wound around the middle tooth of the E-shaped ferromagnetic block along the axial direction, forming a modular structure with the E-shaped ferromagnetic block. The number of modular structures can be flexibly adjusted according to the amount of energy stored in the flywheel energy storage system to achieve the required braking torque. At the same time, the braking module has a simple structure, is easy to process and manufacture, and can be directly fixed on the housing, making installation simple.

[0032] (3) When the braking module uses a C-shaped ferromagnetic block, a magnetic shielding block and a second concentrated excitation winding wound around the circumference of the C-shaped ferromagnetic block, the magnetic shielding block can effectively reduce the leakage magnetic flux inside the housing, and at the same time reduce the amount of copper used in the excitation winding while achieving a good eddy current braking effect.

[0033] (4) When the braking module uses an upper arc-shaped ferromagnetic block, a lower arc-shaped ferromagnetic block, and a ring-shaped excitation winding, with the arc-shaped ferromagnetic blocks arranged on both sides aligned along the flywheel axis, the distribution of the magnetic field on the flywheel circumference is changed by arranging the arc-shaped ferromagnetic blocks on both sides of the ring-shaped excitation winding. Eddy currents are formed on the flywheel, and the magnetic field generated by the eddy currents interacts with the magnetic field generated by the excitation winding to form an electromagnetic braking torque. This scheme makes the ferromagnetic blocks easy to process and install, and can achieve an emergency braking effect.

[0034] (5) When the arc-shaped ferromagnetic blocks are arranged alternately along the flywheel axis on the upper and lower sides, the number of magnetic poles is increased, the frequency of eddy currents in the flywheel is increased, thereby enhancing the emergency braking effect of the flywheel. This scheme is also easy to process and install.

[0035] (6) When the ferromagnetic blocks are right-angled upper ferromagnetic blocks and right-angled lower ferromagnetic blocks, the right-angled ferromagnetic blocks above and below the annular excitation winding contact the side of the annular excitation winding, are staggered along the axial direction, and are evenly distributed along the circumference to form a claw pole structure, which increases the eddy current in the flywheel rotor, thereby enhancing the electromagnetic braking torque.

[0036] In summary, the eddy current braking device of the present invention can ensure emergency braking of the flywheel in the event of a sudden situation, improve the safety of system operation, and is applicable to various metal flywheel energy storage motors. Attached Figure Description

[0037] Figure 1 This is a half-sectional view of the flywheel energy storage system of the eddy current braking device in Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the eddy current braking device provided in Embodiment 1 of the present invention;

[0039] Figure 3 This is a schematic diagram of the eddy current braking device provided in Embodiment 2 of the present invention;

[0040] Figure 4 This is a schematic diagram of the eddy current braking device provided in Embodiment 3 of the present invention;

[0041] Figure 5 This is a schematic diagram of the eddy current braking device provided in Embodiment 4 of the present invention;

[0042] Figure 6 This is a schematic diagram of the eddy current braking device provided in Embodiment 5 of the present invention;

[0043] Figure 7 This is a magnetic flux path diagram of the eddy current braking device provided in Embodiment 1 of the present invention;

[0044] Figure 8 This is a magnetic flux path diagram of the eddy current braking device provided in Embodiment 2 of the present invention;

[0045] Figure 9 This is a magnetic flux path diagram of the eddy current braking device provided in Embodiment 3 of the present invention;

[0046] Figure 10 This is a magnetic flux path diagram of the eddy current braking device provided in Embodiment 5 of the present invention.

[0047] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0048] 1-Upper end cover, 2-Housing, 3-Magnetic shielding block, 4-Flywheel, 501-E-shaped ferromagnetic block, 502-C-shaped ferromagnetic block, 503-Arc-shaped upper ferromagnetic block, 504-Arc-shaped lower ferromagnetic block, 505-Right-angled upper ferromagnetic block, 506-Right-angled lower ferromagnetic block, 601-First concentrated excitation winding, 602-Second concentrated excitation winding, 603-Annular excitation winding, 7-Lower end cover, 8-High-speed motor, 9-Motor shaft, 10-Screw, 11, 12, 13, and 14 are all main magnetic flux paths, 15-Gear, 16-Magnetic yoke. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0050] In this invention, the terms "first," "second," etc., used in the invention and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0051] like Figure 1 As shown, the flywheel energy storage motor eddy current braking device provided by the present invention mainly includes: a housing 2, an upper end cover 1, a lower end cover 7, a flywheel 4, and a braking module.

[0052] The housing 2 is fixed between the upper end cover 1 and the lower end cover 7, and together with the upper end cover 1 and the lower end cover 7, they form a vacuum chamber. The upper end cover 1 and the lower end cover 7 are respectively set on the upper and lower sides of the flywheel 4, that is, the flywheel 4 is set in the vacuum chamber formed by the upper end cover 1 and the lower end cover 7, and the flywheel 4 is driven to rotate by the energy storage motor set above the flywheel.

[0053] The braking module includes ferromagnetic blocks and excitation windings. The excitation windings are wound around the ferromagnetic blocks, or the excitation windings are arranged between the ferromagnetic blocks. N ferromagnetic blocks are evenly arranged around the flywheel in four directions, and there are gaps between adjacent ferromagnetic blocks or gaps on each ferromagnetic block, where N is an integer greater than or equal to 1.

[0054] The inner surface of each ferromagnetic block forms an air gap with the outer surface of the flywheel 4, and the outer surface of each ferromagnetic block is in contact with the inner surface of the housing 2.

[0055] The housing 2 is preferably made of ferromagnetic material, such as Q235A, to serve as a magnetic conductor; and the housing 2 is fixed between the upper end cover 1 and the lower end cover 7, and surrounds the outside of the ferromagnetic block and the excitation winding to fix the various components.

[0056] The flywheel 4 is made of alloy steel, preferably 40Cr.

[0057] The magnetic poles formed after the ferromagnetic block is energized can be arranged in an NNSS or NSNS pattern.

[0058] Preferably, axial grooves are formed on the inner surface of the ferromagnetic block to increase the frequency of eddy current changes, improve eddy current loss on the flywheel, and enhance braking effect.

[0059] Based on the above design, a number of ferromagnetic blocks are evenly distributed along the circumference of the flywheel. Different positions correspond to different magnetic fields; the air gap magnetic field is larger where there are ferromagnetic blocks and smaller where there are no blocks. When the braking device operates, a DC excitation current is passed through the excitation winding, generating an excitation magnetic field in the air gap. According to the principle of electromagnetic induction, the magnetic field at the same position on the flywheel continuously alternates, inducing an electromotive force in the flywheel and generating eddy currents. The magnetic field generated by these eddy currents opposes the change in the original magnetic field, interacting with the excitation magnetic field to produce an electromagnetic braking torque opposite to the flywheel's direction of motion, thus achieving emergency braking. Furthermore, the required braking torque can be adjusted by changing the number of ferromagnetic blocks according to the amount of energy stored in the flywheel energy storage system. This eddy current braking method results in fast braking response, high reliability, and is a non-contact braking method, eliminating the drawbacks of rapid wear and high noise levels associated with high-speed flywheel operation.

[0060] The present invention will be further described in detail below with reference to specific embodiments.

[0061] Example 1

[0062] See Figure 1 , combined Figure 2 and Figure 7As shown, in this embodiment, the braking module includes an E-shaped ferromagnetic block 501 and a first concentrated excitation winding 601. The E-shaped ferromagnetic block includes teeth 15 and a yoke 16. The inner arc surface of each tooth forms an air gap with the outer surface of the flywheel 4, and the outer arc surface of the yoke contacts the inner surface of the housing 2. The first concentrated excitation winding 601 is wound around the middle tooth of the E-shaped ferromagnetic block 501 along the axial direction of the middle tooth. Each E-shaped ferromagnetic block and each first concentrated excitation winding 601 form a modular structure, with N units evenly arranged circumferentially, where N is an integer greater than or equal to 1. The number of modular structures can be flexibly adjusted according to the energy stored in the flywheel energy storage system to achieve the required braking torque. Furthermore, the device has a simple structure, greatly facilitating processing, manufacturing, and installation.

[0063] Preferably, a toothed groove is formed along the axial direction on the inner arc surface of the E-shaped ferromagnetic block 501 to increase the frequency of eddy current changes, improve eddy current loss on the flywheel, and enhance the braking effect.

[0064] Preferably, there is a gap between adjacent E-shaped ferromagnetic blocks 501.

[0065] In this embodiment, during emergency braking, the main magnetic flux path 11 generated by the first concentrated excitation winding 601, such as... Figure 7 As shown, the main magnetic flux path 11 is: E-shaped ferromagnetic block 501 intermediate tooth → air gap → flywheel 4 → air gap → E-shaped ferromagnetic block 501 yoke → E-shaped ferromagnetic block 501 intermediate tooth. During normal operation of the flywheel energy storage motor, the first concentrated excitation winding 601 is not energized, and there is no periodically changing magnetic field on the outer surface of the flywheel 4. Therefore, there is no eddy current loss in the flywheel, which does not affect the energy conversion efficiency of the motor.

[0066] Example 2

[0067] See Figure 1 , combined Figure 3 and Figure 8 As shown, unlike Embodiment 1, in this embodiment, the braking module includes a C-shaped ferromagnetic block 502 and a second concentrated excitation winding 602. A groove is formed in the circumferential center of the C-shaped ferromagnetic block 502, and the second concentrated excitation winding 602 is wound circumferentially around the C-shaped ferromagnetic block along this groove. N C-shaped ferromagnetic blocks 502 and the second concentrated excitation winding 602 are evenly arranged along the circumference of the flywheel, where N is an integer greater than or equal to 1; and there are gaps between adjacent C-shaped ferromagnetic blocks 502.

[0068] As a preferred embodiment, in order to reduce magnetic leakage of the housing 2, a magnetic shielding block 3 is also installed on the outer side of each C-shaped ferromagnetic block 502; the outer side of the magnetic shielding block 3 is fixed to the inner side of the housing 2, and the inner side of each C-shaped ferromagnetic block 502 forms an air gap with the outer surface of the flywheel 4.

[0069] Preferably, each ferromagnetic block in this embodiment is an integrated structure with a C-shaped cross-section; the material of the magnetic shielding block includes aluminum alloy.

[0070] Preferably, a toothed groove is formed along the axial direction on the inner arc surface of the C-shaped ferromagnetic block 502 to increase the frequency of eddy current changes, improve eddy current loss on the flywheel, and enhance the braking effect.

[0071] In this embodiment, during emergency braking, the main magnetic flux path 12 generated by the second concentrated excitation winding 602, such as... Figure 8 As shown. The main magnetic flux path 12 is: C-shaped ferromagnetic block 502 → air gap → flywheel 4 → air gap → C-shaped ferromagnetic block 502. During normal operation of the flywheel energy storage motor, the second concentrated excitation winding 602 is not energized, and there is no periodically changing magnetic field on the outer surface of the flywheel. Therefore, there is no eddy current loss in the flywheel, which does not affect the energy conversion efficiency of the motor.

[0072] This solution achieves good eddy current braking effect while reducing the amount of copper used in the excitation winding, thus saving costs.

[0073] Example 3

[0074] See Figure 1 , combined Figure 4 and Figure 9 As shown, unlike Embodiment 1, in this embodiment, the braking module includes an arc-shaped upper ferromagnetic block 503, an arc-shaped lower ferromagnetic block 504, and an annular excitation winding 603. The annular excitation winding 603 is disposed between the arc-shaped upper ferromagnetic block 503 and the arc-shaped lower ferromagnetic block 504, and surrounds the outside of the flywheel, and is fixed inside the housing. There is an air gap between the annular excitation winding 603 and the flywheel. The arc-shaped upper ferromagnetic block 503 and the arc-shaped lower ferromagnetic block 504 are aligned along the axial direction of the flywheel, and the arc-shaped upper ferromagnetic block 503 and the arc-shaped lower ferromagnetic block 504 are evenly arranged along the circumference of the flywheel, forming an air gap with the outer circumferential surface of the flywheel 4.

[0075] Specifically, the upper arc-shaped ferromagnetic block 503 is located above the annular excitation winding 603, and its inner arc surface forms an air gap with the outer surface of the flywheel, while its outer arc surface contacts the inner surface of the housing. The lower arc-shaped ferromagnetic block 504 is located below the annular excitation winding 603 and is aligned with the upper arc-shaped ferromagnetic block 503 along the flywheel axis. Furthermore, there is a gap between adjacent upper arc-shaped ferromagnetic blocks 503 and between adjacent lower arc-shaped ferromagnetic blocks 504.

[0076] Preferably, axial grooves are formed on the inner arc surfaces of the upper arc-shaped ferromagnetic block 503 and the lower arc-shaped ferromagnetic block 504 to increase the frequency of eddy current changes, improve eddy current loss on the flywheel, and enhance braking effect.

[0077] In other embodiments, the upper arc-shaped ferromagnetic block 503 and the lower arc-shaped ferromagnetic block 504 may also be other ferromagnetic blocks that can be adapted to the entire system.

[0078] When the toroidal excitation winding 603 is energized, due to the modulation effect of the upper arc-shaped ferromagnetic block 503 and the lower arc-shaped ferromagnetic block 504 on the excitation magnetic field, the flywheel 4 is in a periodically changing working magnetic field, and eddy currents are induced in the flywheel 4.

[0079] In this embodiment, during emergency braking, the main magnetic flux path 13 generated by the annular excitation winding 603, such as Figure 9 As shown, the main magnetic flux path 13 is: upper arc-shaped ferromagnetic block 503 → air gap → flywheel 4 → air gap → lower arc-shaped ferromagnetic block 504 → housing 2 → upper arc-shaped ferromagnetic block 503. The eddy current magnetic field and the excitation magnetic field interact to generate a braking torque opposite to the rotation direction of the flywheel 4.

[0080] Example 4

[0081] See Figure 1 , combined Figure 4 As shown, unlike Embodiment 3, in this embodiment, the arc-shaped upper ferromagnetic block 503 and the arc-shaped lower ferromagnetic block 504 are staggered along the flywheel axis and form an air gap with the outer circumferential surface of the flywheel 4. Specifically, the upper end face of the annular excitation winding 603 contacts the lower end face of the arc-shaped upper ferromagnetic block 503, and the lower end face of the annular excitation winding 603 contacts the upper end face of the arc-shaped lower ferromagnetic block 504. The inner surfaces of the arc-shaped upper ferromagnetic block 503, the arc-shaped lower ferromagnetic block 504, and the annular excitation winding 603 form an air gap with the outer surface of the flywheel 4, and the length of the air gap corresponding to the annular excitation winding 603 is equal to the length of the air gap corresponding to the arc-shaped upper ferromagnetic block 503 and the arc-shaped lower ferromagnetic block 504.

[0082] Because the upper arc-shaped ferromagnetic block 503 and the lower arc-shaped ferromagnetic block 504 are distributed at intervals along the circumference, the magnetic reluctance is different at the positions where ferromagnetic blocks are placed compared to the positions where no ferromagnetic blocks are placed. Therefore, when the excitation winding is energized, a periodically changing working magnetic field exists on the circumferential surface of the flywheel 4, generating eddy currents on the flywheel 4.

[0083] Compared to Example 3, in this example, the upper arc-shaped ferromagnetic block 503 and the lower arc-shaped ferromagnetic block 504 are not aligned axially, but rather staggered axially. During emergency braking, the magnetic field on the surface of the flywheel 4 changes each time it passes a ferromagnetic block. Therefore, the staggered distribution of the upper and lower ferromagnetic blocks is equivalent to increasing the number of pole pairs in the air gap magnetic field, increasing the frequency of the eddy currents, and enabling the generation of a larger electromagnetic braking torque.

[0084] Example 5

[0085] See Figure 1 , combined Figure 6 and Figure 10 As shown, unlike Embodiment 4, in this embodiment, the ferromagnetic blocks are a right-angled upper ferromagnetic block 505 and a right-angled lower ferromagnetic block 506. The right-angled upper ferromagnetic blocks 505 and right-angled lower ferromagnetic blocks 506 are staggered along the flywheel axis and form an air gap with the outer circumferential surface of the flywheel 4. Specifically, the upper end face and inner side face of the annular excitation winding 603 are in contact with the right-angled upper ferromagnetic block 505, and the lower end face and inner side face are in contact with the right-angled lower ferromagnetic block 506. The right-angled upper ferromagnetic blocks 505 and right-angled lower ferromagnetic blocks 506 form a claw pole structure. The right-angled upper ferromagnetic blocks 505, right-angled lower ferromagnetic blocks 506, and the inner surface of the annular excitation winding 603 all form an air gap with the outer surface of the flywheel 4. Furthermore, there is a gap between adjacent right-angled upper ferromagnetic blocks 505 and between adjacent right-angled lower ferromagnetic blocks 506.

[0086] Preferably, axial grooves are formed on the inner arc surfaces of the right-angled upper ferromagnetic block 505 and the right-angled lower ferromagnetic block 506 to increase the frequency of eddy current changes, improve eddy current loss on the flywheel, and enhance braking effect.

[0087] Compared to Example 4, in this example, the air gap magnetic field is also modulated by the ferromagnetic block, resulting in eddy currents in the flywheel 4 during braking. Furthermore, the right-angled upper ferromagnetic block 505 and the right-angled lower ferromagnetic block 506 form a claw pole structure. During braking, the magnetic field on the flywheel surface undergoes a greater change when passing the ferromagnetic block, thus inducing larger eddy currents in the flywheel and generating a larger braking torque.

[0088] In this embodiment, during emergency braking, the main magnetic flux path 14 generated by the annular excitation winding 603, such as Figure 10 As shown, the main magnetic flux path 14 is: right-angled upper ferromagnetic block 505 → air gap → flywheel 4 → air gap → right-angled lower ferromagnetic block 506 → housing 2 → right-angled upper ferromagnetic block 505.

[0089] Example 6

[0090] This embodiment provides a flywheel energy storage motor, including an eddy current braking device, a high-speed motor 8, a motor shaft 9, and a screw 10. The eddy current braking device is the device described in any one of the embodiments 1-5 above.

[0091] Specifically, the high-speed motor 8 is positioned above the flywheel 4, and the upper end face of the flywheel 4 is connected to the motor shaft 9, or the flywheel 4 and the motor shaft 9 are integrally forged.

[0092] A flange is provided below the motor shaft 9. An annular groove is opened on the upper end face of the flywheel 4. The flange at the lower end of the motor shaft 9 is embedded in the groove on the upper end face of the flywheel 4 and is installed with an interference fit with the central boss of the flywheel 4. The flange is axially connected to the upper end face of the flywheel 4 by a screw 10.

[0093] The eddy current braking device of the present invention is applicable to various metal flywheel energy storage motors, such as permanent magnet motors, synchronous reluctance motors, induction motors, induction sub-motors, etc., and has a wide range of applications.

[0094] The various braking module structures provided by this invention, in conjunction with other components, have achieved good results in eddy current braking. Furthermore, this invention is the first to apply eddy current braking to a flywheel energy storage motor, resulting in excellent braking performance.

[0095] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An eddy current braking device for a flywheel energy storage motor, characterized in that, include: The casing (2), the upper end cover (1), the lower end cover (7), the flywheel (4), and the braking module; The housing (2) is fixed between the upper end cover (1) and the lower end cover (7), and together with the upper end cover (1) and the lower end cover (7), forms a vacuum cavity. The flywheel (4) is located in the vacuum cavity and is driven to rotate by an energy storage motor located above the flywheel (4). The braking module includes ferromagnetic blocks and excitation windings; the ferromagnetic blocks are evenly arranged around the flywheel (4), and there are gaps between adjacent ferromagnetic blocks or gaps on each ferromagnetic block; The inner surface of each of the ferromagnetic blocks forms an air gap with the outer surface of the flywheel (4), and the outer surface of each of the ferromagnetic blocks is in contact with the inner surface of the housing (2); The braking module includes an E-shaped ferromagnetic block (501) and a first concentrated excitation winding (601). The E-shaped ferromagnetic block (501) includes teeth and a yoke. The inner arc surface of the teeth forms an air gap with the outer surface of the flywheel (4), and the outer arc surface of the yoke contacts the inner surface of the housing (2). The first concentrated excitation winding (601) is wound around the middle tooth of the E-shaped ferromagnetic block (501) along the axial direction of the tooth; Alternatively, the braking module includes a C-shaped ferromagnetic block (502) and a second concentrated excitation winding (602). The C-shaped ferromagnetic block (502) has a groove in the center of its circumference, and the second concentrated excitation winding (602) is wound around the C-shaped ferromagnetic block (502) along the groove in the circumference. Alternatively, the braking module may include an arc-shaped upper ferromagnetic block (503), an arc-shaped lower ferromagnetic block (504), and a ring-shaped excitation winding (603). The annular excitation winding (603) is disposed between the upper arc-shaped ferromagnetic block (503) and the lower arc-shaped ferromagnetic block (504), and surrounds the outside of the flywheel (4) with an air gap between it and the flywheel (4); The upper arc-shaped ferromagnetic block (503) and the lower arc-shaped ferromagnetic block (504) are aligned along the flywheel axis; Alternatively, the braking module may include an arc-shaped upper ferromagnetic block (503), an arc-shaped lower ferromagnetic block (504), and a ring-shaped excitation winding (603). The annular excitation winding (603) is disposed between the upper arc-shaped ferromagnetic block (503) and the lower arc-shaped ferromagnetic block (504), and surrounds the outside of the flywheel (4) with an air gap between it and the flywheel (4); The upper arc-shaped ferromagnetic block (503) and the lower arc-shaped ferromagnetic block (504) are staggered along the flywheel axis; Alternatively, the braking module may include a right-angled upper ferromagnetic block (505), a right-angled lower ferromagnetic block (506), and a ring-shaped excitation winding (603). The annular excitation winding (603) is disposed between the right-angled upper ferromagnetic block (505) and the right-angled lower ferromagnetic block (506), and surrounds the outside of the flywheel (4) with an air gap between it and the flywheel (4); The right-angled upper ferromagnetic block (505) and the right-angled lower ferromagnetic block (506) are staggered along the flywheel axis, and the right-angled upper ferromagnetic block (505) and the right-angled lower ferromagnetic block (506) form a claw pole structure.

2. The eddy current braking device according to claim 1, characterized in that, When the braking module includes a C-shaped ferromagnetic block (502) and a second concentrated excitation winding (602), it also includes a magnetic isolation block (3) disposed on the outer side of each C-shaped ferromagnetic block (502). The outer side of the magnetic isolation block (3) is fixed to the inner surface of the housing (2), and the inner side of each C-shaped ferromagnetic block (502) forms an air gap with the outer surface of the flywheel (4).

3. The eddy current braking device according to claim 1 or 2, characterized in that, The inner surface of the ferromagnetic block is provided with axial grooves.

4. A flywheel energy storage motor, characterized in that, It includes a high-speed motor (8), a motor shaft (9) and an eddy current braking device; the high-speed motor (8) is located above the flywheel (4), and the upper end face of the flywheel (4) is connected to the motor shaft (9); The eddy current braking device is the eddy current braking device according to any one of claims 1-3.

5. The flywheel energy storage motor according to claim 4, characterized in that, It also includes a flange and a screw (10) located at the lower end of the motor shaft (9); The flywheel (4) has an annular groove on its upper end face. The flange is embedded in the groove and is installed with an interference fit with the central boss of the flywheel (4). The flange is axially connected to the upper end face of the flywheel (4) through the screw (10).

Images