A flywheel energy storage device with full magnetic suspension

Abstract

The utility model is suitable for the technical field of electric energy storage, provides a kind of full magnetic suspension's flywheel energy storage device, including permanent magnet synchronous motor and flywheel mechanism, the top of permanent magnet synchronous motor is provided with upper radial magnetic suspension bearing casing;This full magnetic suspension flywheel energy storage device reaches the great reduction flywheel energy storage system in friction and brings about the loss extension its service life, has improved the stability when flywheel rotor high-speed operation, has reduced the noise brought by vibration, compact structure and adapt high speed scene purposes, solve the conventional flywheel rotating shaft integration structure in prior art due to large volume, the hardenability of flywheel center is poor and then leads to the insufficient flywheel strength and conventional flywheel energy storage rotor axial and radial degree of freedom rely on bearing connection limit, poor stability when high-speed operation, vibration and noise, further still will produce additional heat, the problem of low energy conversion efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of electrical energy storage technology, and in particular relates to a fully magnetically levitated flywheel energy storage device. Background Technology

[0002] With the continuous development of new energy technologies, energy storage technology has received widespread attention. Among existing energy storage technologies, flywheel energy storage devices have gained increasing attention due to their advantages such as good dynamic performance, high charge / discharge cycles, fast speed, long lifespan, and low maintenance frequency. Flywheel energy storage devices include flywheel rotors, permanent magnet synchronous motors, and magnetic levitation bearing systems. In conventional flywheel energy storage devices, the magnetic levitation bearing system typically uses either mechanical bearings or magnetic levitation bearings. However, mechanical bearings alone suffer from high frictional losses at high speeds, and the lubricant evaporates over time, significantly reducing their lifespan. While hybrid bearings (mechanical + magnetic levitation combination) can reduce axial frictional losses caused by the flywheel rotor's gravity, some wear still exists (the backup mechanical bearing may experience instantaneous losses when a fault occurs). Furthermore, the use of hybrid bearings cannot guarantee the operational stability of the flywheel rotor system at high speeds, leading to significant vibration, friction, and energy loss due to heat generation. Therefore, minimizing frictional losses and improving the radial and axial operational stability of the flywheel rotor during high-speed operation has always been a major concern. For the flywheel structure, which is an important part of the flywheel energy storage motor, the flywheel has a large inertia and its strength is an important factor to consider at high speeds. Conventional flywheel-shaft integrated structures are large in size and have poor hardenability at the center of the flywheel, resulting in insufficient flywheel strength. Therefore, a reasonable structural design for the flywheel is crucial. Utility Model Content

[0003] To overcome the shortcomings of existing technologies, this utility model provides a fully magnetically levitated flywheel energy storage device, including a permanent magnet synchronous motor and a flywheel mechanism. The top of the permanent magnet synchronous motor is provided with an upper radial magnetic levitation bearing housing. The upper radial magnetic levitation bearing housing, the permanent magnet synchronous motor, and the flywheel mechanism are interconnected. An upper end cover is fixed to the top of the upper radial magnetic levitation bearing housing. An upper rotating shaft, extending into the flywheel mechanism, is rotatably connected to the bottom of the upper end cover. A lower end cover is fixedly connected to the bottom of the flywheel mechanism. A lower rotating shaft is rotatably connected to the top of the lower end cover. Both the upper and lower rotating shaft supports are fixedly connected to the flywheel. The device is characterized in that: an upper radial magnetic levitation bearing rotor core is fixedly fixed to the outside of the upper rotating shaft; an upper radial magnetic levitation bearing stator core, surrounding the rotor core, is fixedly connected to the inner wall of the upper radial magnetic levitation bearing housing; the inner circular hole of the upper radial magnetic levitation bearing stator core has a circumferential array of protrusions, and an upper radial magnetic levitation bearing excitation coil winding is surrounded by the protrusions.

[0004] Furthermore, the permanent magnet synchronous motor includes a motor housing, with a stator core fixedly connected to the inner wall of the housing, and an armature winding wound around the stator core. An upper transition plate and a lower transition plate are fixedly connected to the upper and lower ends of the motor housing, respectively. Both the upper and lower transition plates have a circular hole at their center. An upper rotating shaft passes through both circular holes and extends into the flywheel mechanism. A motor rotor core located inside the stator core is fixedly connected to the outside of the upper rotating shaft. The outer wall of the rotor core has several annularly arranged grooves, in which permanent magnets are embedded. The upper and lower ends of the rotor core are fixedly connected to two rotor end plates, and the rotor core is surrounded by the stator core.

[0005] Furthermore, the flywheel mechanism includes a flywheel housing, the lower end of which is fixed to a lower end cover, and the upper end of which is fixedly connected to a lower transition plate. A circular groove is formed in the center of the lower end cover, and a mechanical bearing is interference-fitted into the groove. The lower rotating shaft is rotatably connected to the lower end cover via the mechanical bearing. Both the lower and upper rotating shafts are fixedly connected to the flywheel. Circular grooves are formed near the center of the upper and lower end faces of the flywheel, and the upper and lower rotating shafts are connected and fixed within these grooves.

[0006] Furthermore, a lower radial magnetic levitation bearing fixing flange is fixedly connected to the top of the lower end cover, a lower radial magnetic levitation bearing stator core is fixedly connected to the inner wall of the lower radial magnetic levitation bearing fixing flange, a lower radial magnetic levitation bearing rotor core is fixedly connected to the outside of the lower rotating shaft, the lower radial magnetic levitation bearing stator core surrounds the outer circumference of the lower radial magnetic levitation bearing rotor core, and the inner wall of the lower radial magnetic levitation bearing stator core is provided with a plurality of protrusions arranged in a ring array, and a lower radial magnetic levitation bearing excitation coil winding is surrounded on each of the protrusions.

[0007] Furthermore, the top of the lower radial magnetic levitation bearing fixing flange is fixedly connected to an axial magnetic bearing yoke ring. The top of the axial magnetic bearing yoke ring and the bottom of the flywheel are both provided with annular grooves. Axial permanent magnet bearing magnets are embedded in both of the two annular grooves, and the opposing surfaces of the two axial permanent magnet bearing magnets are of the same polarity, forming a repulsive force.

[0008] Furthermore, the bottom of the lower transition plate is fixedly connected to an axially excitation magnetic levitation bearing including an electromagnet yoke, and the lower end face of the electromagnet yoke has an annular groove, in which an electromagnetic coil is embedded.

[0009] Furthermore, a first sealing ring is provided at the connection between the upper radial magnetic levitation bearing housing and the upper end cover and the upper transition plate, a second sealing ring is provided at the connection between the motor housing and the upper transition plate and the lower transition plate, and a third sealing ring is provided at the connection between the flywheel housing and the lower transition plate and the lower end cover.

[0010] The beneficial effects of this utility model are: 1. This fully magnetically levitated flywheel energy storage device achieves non-contact levitation support for the flywheel energy storage motor rotor system through upper and lower radial magnetic levitation bearings, axial electrically excited magnetic levitation bearings, and axial permanent magnet repulsion bearings. This greatly reduces mechanical friction and wear, further reduces temperature rise, and extends the service life of the device.

[0011] 2. This fully magnetically levitated flywheel energy storage device increases the hardenability of the flywheel center and improves the mechanical strength of the flywheel by making the flywheel and shaft separate structures. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the structure of this utility model; Figure 2 This is a cross-sectional view of the radial magnetic levitation bearing of this utility model; Figure 3 This is a schematic diagram of the connection structure between the flywheel rotor and the shaft of this utility model; Figure 4 This is a cross-sectional view of the flywheel mechanism of this utility model; Figure 5 This is a cross-sectional view of the permanent magnet synchronous motor structure of this utility model; Figure 6 This is a schematic diagram of the axial permanent magnet magnetic levitation bearing structure of this utility model; Figure 7 This is a cross-sectional view of the radial magnetic levitation bearing structure of this utility model; Figure 8 This is a schematic diagram of the connection structure between the electromagnet yoke and the electromagnetic coil of this utility model.

[0013] In the diagram: 101, upper end cover; 102, lower end cover; 201, upper transition plate; 202, lower transition plate; 301, upper shaft; 302, lower shaft; 401, upper radial magnetic levitation bearing housing; 402, upper radial magnetic levitation bearing excitation coil winding; 403, upper radial magnetic levitation bearing rotor core; 404, upper radial magnetic levitation bearing stator core; 5, permanent magnet synchronous motor; 501, motor housing; 502, armature winding; 504, motor rotor core; 505, motor stator core; 507, rotor end plate. 601. Electromagnetic yoke; 602. Electromagnetic coil; 7. Flywheel mechanism; 701. Flywheel housing; 702. Flywheel; 801. Axial magnetic bearing yoke ring; 802. Axial permanent magnet bearing magnet; 901. Lower radial magnetic levitation bearing fixing flange; 902. Lower radial magnetic levitation bearing rotor core; 903. Lower radial magnetic levitation bearing stator core; 904. Lower radial magnetic levitation bearing excitation coil winding; 10. Mechanical bearing; 1101. First sealing ring; 1102. Second sealing ring; 1103. Third sealing ring. Detailed Implementation

[0014] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive element, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0015] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0016] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In some descriptions of utility models, "a plurality of" means two or more, unless otherwise explicitly specified.

[0018] Briefly describe the distinguishing features between this utility model and the prior art, which constitute the utility model's inventive point: Example 1, please refer to Figure 1-7 This embodiment provides a fully magnetically levitated flywheel energy storage device, including a permanent magnet synchronous motor 5 and a flywheel mechanism 7. The permanent magnet synchronous motor 5 includes a motor housing 501, with a motor stator core 505 fixedly connected to the inner wall of the motor housing 501. An armature winding 502 is wound on the motor stator core 505. An upper transition plate 201 and a lower transition plate 202 are fixedly connected to the upper and lower ends of the motor housing 501, respectively. Both the upper and lower transition plates 201 and 202 have circular holes at their centers. An upper rotating shaft 301 passes through the two circular holes and extends into the flywheel mechanism 7. A motor rotor core 504 located inside the motor stator core 505 is fixedly connected to the outside of the upper rotating shaft 301. The outer wall of the motor rotor core 504 has several annularly arrayed grooves, in which permanent magnets are embedded. The upper and lower ends of the motor rotor core 504 are fixedly connected to two rotor end plates 507, respectively. The motor rotor core 504 is surrounded by the motor stator core 505.

[0019] The top of the permanent magnet synchronous motor 5 is provided with an upper radial magnetic levitation bearing housing 401. The upper radial magnetic levitation bearing housing 401, the permanent magnet synchronous motor 5, and the flywheel mechanism 7 are connected. An upper end cover 101 is fixed to the top of the upper radial magnetic levitation bearing housing 401. An upper rotating shaft 301 extending into the flywheel mechanism 7 is rotatably connected to the bottom of the upper end cover 101. A lower end cover 102 is fixedly connected to the bottom of the flywheel mechanism 7. A lower rotating shaft 302 is rotatably connected to the top of the lower end cover 102. The upper rotating shaft 301... Both the upper shaft 301 and the lower shaft 302 bracket are fixedly connected to the flywheel 702. The upper shaft 301 is characterized by having an upper radial magnetic levitation bearing rotor core 403 fixedly attached to its exterior. An upper radial magnetic levitation bearing stator core 404, surrounding the upper radial magnetic levitation bearing rotor core 403, is fixedly connected to the inner wall of the upper radial magnetic levitation bearing housing 401. The upper radial magnetic levitation bearing stator core 404 has a circular array of protrusions in its inner hole, and an upper radial magnetic levitation bearing excitation coil winding 402 surrounds the protrusions. The flywheel mechanism 7 includes a flywheel housing 701. The lower end of the flywheel housing 701 is fixed to the lower end cover 102, and its upper end is fixedly connected to the lower transition plate 202. A circular groove is formed in the center of the lower end cover 102, and a mechanical bearing 10 is interference-fitted into the groove. The lower shaft 302 is rotatably connected to the lower end cover 102 via the mechanical bearing 10. Both the lower shaft 302 and the upper shaft 301 are fixedly connected to the flywheel 702. The flywheel 702 is a separate structure from the upper and lower shafts. Annular grooves are formed near the center of both the top and bottom of the flywheel 702, giving it an H-shaped axial cross-section. The ends of the upper and lower shafts are respectively embedded in the two annular grooves and fixed to the flywheel 702 with screws. The H-shaped flywheel design increases its hardenability, resulting in higher strength and adaptability to high-speed operation, thus ensuring the structural strength of the rotor system. A lower radial magnetic levitation bearing fixing flange 901 is fixedly connected to the top of the lower end cover 102. A lower radial magnetic levitation bearing stator core 903 is fixedly connected to the inner wall of the lower radial magnetic levitation bearing fixing flange 901. A lower radial magnetic levitation bearing rotor core 902 is fixedly connected to the outside of the lower rotating shaft 302. The lower radial magnetic levitation bearing stator core 903 surrounds the outer circumference of the lower radial magnetic levitation bearing rotor core 902. The inner wall of the lower radial magnetic levitation bearing stator core 903 is provided with several protrusions arranged in a ring array, and each of the protrusions is surrounded by a lower radial magnetic levitation bearing excitation coil winding 904. The electromagnetic force of the radial magnetic levitation bearing ensures the stability of radial offset when the flywheel energy storage rotor system operates at high speed, reducing the additional energy loss caused by friction and heat due to offset and vibration. The top of the lower radial magnetic levitation bearing fixing flange 901 is fixedly connected to an axial magnetic bearing yoke ring 801. The top of the axial magnetic bearing yoke ring 801 and the bottom of the flywheel 702 are both provided with annular grooves. An axial permanent magnet bearing magnet 802 is embedded in both annular grooves, and the opposite surfaces of the two axial permanent magnet bearing magnets 802 are of the same polarity, forming a repulsive force.The flywheel energy storage rotor system's self-weight is offset by the axial magnetic bearing yoke ring 801 and the axial permanent magnet bearing magnet 802. The combination of axial and radial magnetic levitation bearings achieves non-contact suspension support for the flywheel energy storage motor rotor system, reducing mechanical friction and wear, further lowering the temperature rise, and extending the service life of the device.

[0020] Example 2, please refer to Figure 8 The bottom of the lower transition plate 202 is fixedly connected to an axially excitation magnetic levitation bearing 6, which includes an electromagnet yoke 601. An annular groove is opened on the lower end face of the electromagnet yoke 601, and an electromagnetic coil 602 is embedded in the annular groove.

[0021] By setting up the electromagnet yoke 601 and the electromagnetic coil 602, the axial magnetic bearing yoke ring 801 and the axial permanent magnet bearing magnet 802 can be further assisted in counteracting the self-weight of the flywheel energy storage rotor system.

[0022] Example 3: A first sealing ring 1101 is provided at the connection between the upper radial magnetic levitation bearing housing 401 and the upper end cover 101 and the upper transition plate 201. A second sealing ring 1102 is provided at the connection between the motor housing 501 and the upper transition plate 201 and the lower transition plate 202. A third sealing ring 1103 is provided at the connection between the flywheel housing 701 and the lower transition plate 202 and the lower end cover 102.

[0023] By setting sealing rings at each connection point, the cavity where the flywheel energy storage rotor system is located can be guaranteed to be a vacuum environment after evacuation, preventing air from entering and ensuring the stability of the system's operating environment.

[0024] In summary, this fully magnetically levitated flywheel energy storage device achieves the goals of significantly reducing frictional losses in the flywheel energy storage system, extending its service life, improving the stability of the flywheel rotor during high-speed operation, reducing noise caused by vibration, and having a compact structure suitable for high-speed scenarios. It solves the problems of conventional flywheel-shaft integrated structures in existing technologies, which suffer from large volume, poor hardenability of the flywheel center leading to insufficient flywheel strength, and the fact that conventional flywheel energy storage rotors rely on bearings and other connections for axial and radial degrees of freedom, resulting in poor stability, high vibration and noise during high-speed operation, and further generating additional heat and low energy conversion efficiency.

[0025] It is understood that those skilled in the art can combine various implementation methods in the above embodiments under the guidance of the above examples to obtain technical solutions with multiple implementation methods.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A fully magnetically levitated flywheel energy storage device, comprising a permanent magnet synchronous motor (5) and a flywheel mechanism (7), wherein an upper radial magnetic levitation bearing housing (401) is provided on the top of the permanent magnet synchronous motor (5), the upper radial magnetic levitation bearing housing (401), the permanent magnet synchronous motor (5) and the flywheel mechanism (7) are connected to each other, an upper end cover (101) is fixed on the top of the upper radial magnetic levitation bearing housing (401), an upper rotating shaft (301) extending into the flywheel mechanism (7) is rotatably connected to the bottom of the upper end cover (101), a lower end cover (102) is fixedly connected to the bottom of the flywheel mechanism (7), a lower rotating shaft (302) is rotatably connected to the top of the lower end cover (102), and the supports of the upper rotating shaft (301) and the lower rotating shaft (302) are both fixedly connected to the flywheel (702), characterized in that: The upper rotating shaft (301) is fixed with an upper radial magnetic levitation bearing rotor core (403) on the outside. The upper radial magnetic levitation bearing housing (401) is fixedly connected with an upper radial magnetic levitation bearing stator core (404) surrounding the upper radial magnetic levitation bearing rotor core (403). The upper radial magnetic levitation bearing stator core (404) has a circular array of protrusions in its inner circular hole, and the upper radial magnetic levitation bearing excitation coil winding (402) is surrounded on the protrusions.

2. The fully magnetically levitated flywheel energy storage device as described in claim 1, characterized in that, The permanent magnet synchronous motor (5) includes a motor housing (501), a motor stator core (505) is fixedly connected to the inner wall of the motor housing (501), an armature winding (502) is wound on the motor stator core (505), an upper transition plate (201) and a lower transition plate (202) are fixedly connected to the upper and lower ends of the motor housing (501) respectively, and a circular hole is opened in the center of the upper transition plate (201) and the lower transition plate (202). The upper rotating shaft (301) passes through the two circular holes in sequence and extends into the flywheel mechanism (7). The upper rotating shaft (301) is fixedly connected to the outside of the upper rotating shaft (301) and the motor rotor core (504) is located inside the motor stator core (505). The upper and lower ends of the motor rotor core (504) are fixedly connected to two rotor end plates (507) respectively.

3. The fully magnetically levitated flywheel energy storage device as described in claim 2, characterized in that, The flywheel mechanism (7) includes a flywheel housing (701), the lower end of which is fixed on the lower end cover (102), and the upper end is fixedly connected to the lower transition plate (202). A circular groove is provided in the center of the lower end cover (102), and a mechanical bearing (10) is interference-fitted into the groove. The lower rotating shaft (302) is rotatably connected to the lower end cover (102) through the mechanical bearing (10). Both the lower rotating shaft (302) and the upper rotating shaft (301) are fixedly connected to the flywheel (702).

4. The fully magnetically levitated flywheel energy storage device as described in claim 3, characterized in that, The lower end cover (102) is fixedly connected to the top of a lower radial magnetic levitation bearing fixing flange (901). The lower radial magnetic levitation bearing stator core (903) is fixedly connected to the inner wall of the lower radial magnetic levitation bearing fixing flange (901). The lower radial magnetic levitation bearing rotor core (902) is fixedly connected to the outside of the lower shaft (302). The lower radial magnetic levitation bearing stator core (903) surrounds the outer periphery of the lower radial magnetic levitation bearing rotor core (902). The inner wall of the lower radial magnetic levitation bearing stator core (903) is provided with a number of protrusions arranged in a ring array, and the lower radial magnetic levitation bearing excitation coil winding (904) is surrounded on each of the protrusions.

5. The fully magnetically levitated flywheel energy storage device as described in claim 4, characterized in that, The top of the lower radial magnetic levitation bearing fixing flange (901) is fixedly connected to an axial magnetic bearing yoke ring (801). The top of the axial magnetic bearing yoke ring (801) and the bottom of the flywheel (702) are both provided with annular grooves. Axial permanent magnet bearing magnets (802) are embedded in both of the two annular grooves, and the opposite faces of the two axial permanent magnet bearing magnets (802) are of the same polarity.

6. The fully magnetically levitated flywheel energy storage device as described in claim 3, characterized in that, The bottom of the lower transition plate (202) is fixedly connected to an electromagnet yoke (601), and an annular groove is opened on the lower end face of the electromagnet yoke (601), and an electromagnetic coil (602) is embedded in the annular groove.

7. The fully magnetically levitated flywheel energy storage device as described in claim 3, characterized in that, A first sealing ring (1101) is provided at the connection between the upper radial magnetic levitation bearing housing (401) and the upper end cover (101) and the upper transition plate (201). A second sealing ring (1102) is provided at the connection between the motor housing (501) and the upper transition plate (201) and the lower transition plate (202). A third sealing ring (1103) is provided at the connection between the flywheel housing (701) and the lower transition plate (202) and the lower end cover (102).

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