Electric and power generation separated flywheel energy storage device and system
By separating the electric and generating energy transmission channels in the flywheel energy storage device and using two sets of armature windings and magnetic bearings with different powers, the problem of high loss caused by sharing the armature winding is solved, and higher power output and system stability are achieved.
Patent Information
- Application Number
- CN202510688276.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-27
- Publication Date
- 2025-09-19
AI Technical Summary
In existing flywheel energy storage devices, the motoring state and the power generation state share the same armature winding, resulting in high energy transfer losses, limiting the charging and discharging power, and failing to meet instantaneous high-power discharge requirements.
The design of separating electric and power generation separates the electric and power generation energy transmission channels. Two sets of armature windings and magnetic bearing structures with different powers are used to achieve the selection of energy channels with different powers, reduce losses and improve system flexibility.
The compatibility and stability of the flywheel energy storage device are improved, the armature loss and heat generation are reduced, the service life is extended, and the reliability and power output capacity of the system are enhanced.
Smart Images
Figure CN120675345A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of flywheel energy storage, and in particular to a flywheel energy storage device and system for separating electric power generation and electric motor generation. Background Art
[0002] Flywheel energy storage devices have the characteristics of high power density, high charge and discharge frequency, fast working response, and environmental protection and pollution-free. They are a new type of green energy and have been applied in rail transportation, grid frequency regulation, new energy power generation and uninterruptible power supply, and have good development prospects.
[0003] Flywheel energy storage devices operate in two modes: motoring and generating. In the motoring mode, the motor drives the flywheel rotor, utilizing the flywheel's high inertia and continuously increasing speed to convert electrical energy into mechanical energy for storage. In the generating mode, the flywheel rotor decelerates and drives the motor rotor to generate electricity. Typically, both modes utilize the same armature winding—the motor's stator armature winding—for bidirectional energy transfer. The amount of energy a flywheel energy storage device can store depends primarily on the size and speed of the flywheel rotor, while its charge and discharge power is determined by the motor's power. If motor power cannot be increased due to factors like size and cost, this directly limits the flywheel energy storage device's charge and discharge power, a crucial metric. This makes it difficult to fully utilize its advantages in applications requiring instantaneous high-power discharge. Summary of the Invention
[0004] In response to the defects of the existing technology and the need for improvement, this patent provides a flywheel energy storage device and system with separated electric and power generation. Its purpose is to separate the electric and power generation energy transmission channels of the flywheel energy storage motor, increase the diversity of energy channel selection for charging and discharging, reduce the upper limit of loss and heat generation of a single energy channel, indirectly increase the upper limit of operating power, and at the same time enable the control system to select energy channels with different charging and discharging power according to different working conditions and motor states.
[0005] The structure is designed to allow for free combination of motors of different powers and flywheels of different energy storage capacities, and the mechanical structure is standardized for quick and easy installation and disassembly.
[0006] In order to achieve the above-mentioned separation of the electric and power generation energy transmission channels of the flywheel energy storage motor, increase the diversity of energy channel selection for charging and discharging, reduce the upper limit of loss and heat generation of a single energy channel, indirectly increase the upper limit of operating power, and at the same time enable the control system to select energy channels with different charging and discharging powers according to different working conditions and motor states, the present invention provides the following technical solutions: a flywheel energy storage device with electric power generation separation, comprising a lower casing, the top of the lower casing is fixedly connected to the upper casing, the top of the lower casing and the bottom of the upper casing are both provided with through holes, and it is characterized in that: a first stator core is arranged inside the lower casing, the first stator core is divided into two sections, the upper and lower sections of the first stator core are both annular structures, and the upper and lower sections of the first stator core are An annular excitation winding and a first armature winding are embedded in sequence between the sub-cores from the outside to the inside along the center direction of the circle. The upper and lower sections of the first stator core are fixedly connected to the inner wall of the lower casing. The flywheel rotor placed in the annular interior of the first stator core is rotatably connected inside the lower casing. The flywheel rotor is a ferromagnetic rotor. The rotor core is rotatably connected inside the upper casing. The rotor core is fixedly connected to the flywheel rotor through a rotating shaft. The inner bottom wall of the lower casing is fixedly connected to a first radial mechanical bearing. The inner top wall of the lower casing is fixedly connected to a magnetic bearing. The lower casing is rotatably connected to the flywheel rotor through the first radial mechanical bearing. The top of the upper casing is fixedly connected to a second radial mechanical bearing. The upper casing is rotatably connected to the rotating shaft through the second radial mechanical bearing.
[0007] Preferably, a second stator core and a second armature winding are fixedly connected to the interior of the upper housing, the second stator core is fixedly connected to the upper housing, the second armature winding is wound around the outside of the second stator core, the rotor core is placed inside the second stator core and the rotor core is fixedly connected to the rotating shaft.
[0008] Preferably, the magnetic bearing includes a ferromagnetic ring and a bearing excitation winding, the top of the ferromagnetic ring is fixedly connected to the lower casing, and magnetic isolation material is arranged between the ferromagnetic ring and the inner top wall of the lower casing. The ferromagnetic ring is a groove structure with an opening facing downward, and the bearing excitation winding is embedded in the ferromagnetic ring. The flywheel rotor is a ferromagnetic rotor, and the flywheel rotor and the magnetic bearing are critically attracted. The ratio of the outer diameter D1 of the ferromagnetic ring to the outer diameter D2 of the flywheel rotor is D1=0.8-0.9D2, the difference between the inner diameter D3 of the ferromagnetic ring and the outer diameter D2 of the flywheel rotor is D3=0.5-0.6D2, the ratio of the outer diameter D1 of the ferromagnetic ring to the outer diameter D4 of the second stator core is D1=10MM-20MM+D4, and the area of the ferromagnetic ring is less than or equal to the area of the magnetic isolation material.
[0009] Preferably, the lower housing is connected to the upper housing at a stop, and a vacuum cavity is formed inside the lower housing and the upper housing.
[0010] Preferably, a boss is fixedly connected to the bottom of the rotating shaft, a notch adapted to the boss is provided on the top of the flywheel rotor, and the rotating shaft and the flywheel rotor are threadedly connected via the boss and the notch.
[0011] Preferably, the first armature winding and the second armature winding are both provided with a wiring device and are electrically connected to an external power supply, and the first armature winding is a three-phase AC winding.
[0012] Preferably, the annular surface of the flywheel rotor is provided with a plurality of regular arc grooves, and the number of the arc grooves is a multiple of the number of rotor pole pairs.
[0013] The present invention also provides a system for a flywheel energy storage device for separation of electric power generation and electric motor power generation, comprising a DC bus, wherein the output end of the DC bus is electrically connected to a low-power inverter and a high-power rectifier DCDC device, wherein the low-power inverter and the high-power rectifier DCDC device are connected in parallel, wherein the output end of the low-power inverter is electrically connected to a charging circuit switch, wherein the other end of the charging circuit switch is electrically connected to a second armature winding, and wherein the output end of the high-power rectifier DCDC device is electrically connected to a discharge circuit switch, wherein the other end of the discharge circuit switch is electrically connected to a first armature winding.
[0014] Preferably, the output end of the DC bus is electrically connected to a high-power inverter and a low-power rectifier DCDC device, the high-power inverter and the low-power rectifier DCDC device are connected in parallel, the output end of the high-power inverter is electrically connected to a charging circuit switch, the other end of the charging circuit switch is electrically connected to the first armature winding, and the output end of the low-power rectifier DCDC device is electrically connected to a discharge circuit switch, the other end of the discharge circuit switch is electrically connected to the second armature winding.
[0015] Preferably, the output end of the DC bus is electrically connected to a small-power inverter and a large-power inverter, the small-power inverter and the large-power inverter are connected in parallel, and the output ends of the small-power inverter and the large-power inverter are electrically connected to a first charge-discharge circuit switch and a second charge-discharge circuit switch, respectively, and the other ends of the first charge-discharge circuit switch and the second charge-discharge circuit switch are electrically connected to the second armature winding and the first armature winding, respectively.
[0016] Compared with the prior art, the present invention provides a flywheel energy storage device and system with separated electric power generation, which has the following beneficial effects:
[0017] 1. This application uses a flywheel energy storage device that separates the electric and power generation energy transmission channels. The flywheel energy storage control system can flexibly select the energy channels for charging and discharging, increase the application range of the device, and improve the compatibility and stability of the flywheel energy storage system.
[0018] 2. This application uses two sets of armature windings with different powers to form an energy channel that separates motoring and power generation, reducing armature loss and heat generation, indirectly improving the power and efficiency of the flywheel energy storage device, and increasing the service life of the device.
[0019] 3. This application uses magnetic bearings to offset the weight of the flywheel rotor, reduce the axial load of the mechanical bearing, and can adjust the excitation current according to the real-time working conditions to ensure that the magnetic force of the magnetic bearing remains unchanged, thereby improving system reliability.
[0020] 4. This application can use charging devices of different power levels and discharge devices of different specifications in combination according to different needs to simplify the design of the flywheel energy storage device. At the same time, the use of standard mechanical interfaces can achieve rapid disassembly and replacement, facilitating maintenance. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic diagram of the structure of the present invention;
[0022] Figure 2 It is a cross-sectional view of the structure of the present invention;
[0023] Figure 3 This is a schematic diagram of the connection structure between the flywheel rotor and the rotating shaft of the present invention;
[0024] Figure 4 This is a schematic diagram of the internal structure of the first motor of the present invention;
[0025] Figure 5 This is a diagram of a system application topology according to an embodiment of the present invention;
[0026] Figure 6 This is a structural diagram of embodiment 2 of the present invention;
[0027] Figure 7 This is a diagram of the system application topology according to the second embodiment of the present invention;
[0028] Figure 8 This is a topological diagram of the system application of embodiment 3 of the present invention.
[0029] In the figure: 1. Lower casing; 2. Upper casing; 301. First stator core; 302. Ring excitation winding; 303. First armature winding; 304. Flywheel rotor; 41. Second stator core; 42. Second armature winding; 43. Rotor core; 5. Rotating shaft; 6. First radial mechanical bearing; 7. Magnetic bearing; 71. Ferromagnetic ring; 72. Bearing excitation winding; 8. Second radial mechanical bearing; 9. Auxiliary magnetic bearing; 91. Auxiliary ferromagnetic ring; 92. Auxiliary bearing excitation winding. DETAILED DESCRIPTION
[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0031] For example 1, please refer to Figure 1-5A flywheel energy storage device and system with electric power generation separation includes a lower casing 1, the top of the lower casing 1 is fixedly connected to the upper casing 2, the top of the lower casing 1 and the bottom of the upper casing 2 are both provided with through holes, the lower casing 1 and the upper casing 2 are connected through the through holes, the lower casing 1 and the upper casing 2 are connected at the stoppers, and a vacuum cavity is formed inside the lower casing 1 and the upper casing 2, a first stator core 301, an annular excitation winding 302, a first armature winding 303 and a flywheel rotor 304 are fixedly connected inside the lower casing 1, the first stator core 301 is divided into two sections, the upper and lower sections of the first stator core 301 are both annular structures, and the first stator core 301 is fixedly connected to the inner wall of the lower casing 1, and the upper and lower sections of the first stator core 301 are connected along the center direction from the outermost part to the outermost part. The annular excitation winding 302 and the first armature winding 303 are embedded inward in sequence, the flywheel rotor 304 is placed in the annular interior of the first stator core 301 and the first armature winding 303, the rotor core 43 is provided inside the upper casing 2, the flywheel rotor 304 and the rotor core 43 are fixedly connected by the rotating shaft 5, the upper casing 2 is also fixedly connected to the second stator core 41 and the second armature winding 42, the second stator core 41 is fixedly connected to the upper casing 2, the second armature winding 42 is wound around the outside of the second stator core 41, the rotor core 43 is placed inside the second stator core 41 and the rotor core 43 is fixedly connected to the rotating shaft 5, the inner bottom wall of the lower casing 1 is fixedly connected to the first radial mechanical bearing 6, the bottom of the flywheel rotor 304 is rotatably connected to the second stator core 41. Inside a radial mechanical bearing 6, a magnetic bearing 7 is fixedly connected to the inner top wall of the lower casing 1. The flywheel rotor 304 is a ferromagnetic rotor, and the flywheel rotor 304 and the magnetic bearing 7 are critically attracted. The magnetic bearing 7 applies suction to the flywheel rotor 304, so that the flywheel rotor 304 is suspended in the lower casing 1. The connection part between the lower end of the flywheel rotor 304 and the first radial mechanical bearing 6 is a few steps forged integrally with the flywheel rotor 304. The top of the flywheel rotor 304 is fixedly connected to the rotating shaft 5. The bottom of the rotating shaft 5 is fixedly connected to a boss. The top of the flywheel rotor 304 is provided with a notch adapted to the boss. The rotating shaft 5 and the flywheel rotor 304 are threadedly connected through the boss and the notch. The rotating shaft 5 and the flywheel rotor 304 adopt a clearance fit on one side and an interference fit on the other side. In addition to the screw holes drilled for connection and fixation, the axial plane is also drilled with a top screw hole for disassembly and assembly. The first armature winding 303 and the second armature winding 42 are both provided with wiring devices and electrically connected to an external power supply. The first armature winding 303 is a three-phase AC winding. The annular surface of the flywheel rotor 304 is provided with a number of regular arc grooves. The number of arc grooves is a multiple of the number of rotor pole pairs. Salient pole teeth are designed on the surface of the flywheel rotor 304 to form a magnetic circuit to guide the stator excitation, thereby forming a magnetic field, silicon-free steel sheets and permanent magnets on the rotor. The magnetic bearing 7 includes a ferromagnetic ring 71 and a bearing excitation winding 72. The top of the ferromagnetic ring 71 is fixedly connected to the lower casing 1. A magnetic isolation material is provided between the ferromagnetic ring 71 and the inner top wall of the lower casing 1. The magnetic isolation material is 304 stainless steel.The area of the magnetic isolation material is greater than or equal to the top surface area of the ferromagnetic ring 71. The ferromagnetic ring 71 is a groove structure with an opening downward. The bearing excitation winding 72 is embedded in the groove of the ferromagnetic ring 71. The ratio of the outer diameter D1 of the ferromagnetic ring 71 to the outer diameter D2 of the flywheel rotor 304 is D1=(0.8-0.9)D2. The difference between the ratio of the inner diameter D3 of the ferromagnetic ring 71 to the outer diameter D2 of the flywheel rotor 304 is D3=(0.5-0.6)D2. The ratio of the outer diameter D1 of the ferromagnetic ring 71 to the outer diameter D4 of the second stator core 41 is D1=(10MM-20MM)+D4. The area of the ferromagnetic ring 71 is less than or equal to the area of the magnetic isolation material. The magnetic bearing 7 is used to offset the weight of the flywheel rotor 304, so that the flywheel rotor 304 can be suspended in the lower housing 1 with axial freedom. The axial load on the mechanical bearing is reduced, and the excitation current can be adjusted according to real-time operating conditions to ensure that the magnetic force of the magnetic bearing remains unchanged, thereby improving system reliability. A second radial mechanical bearing 8 is fixedly connected to the top of the upper housing 2. The upper housing 2 is rotatably connected to the rotating shaft 5 via the second radial mechanical bearing 8. The system also includes a DC busbar, the output end of which is electrically connected to a low-power inverter and a high-power rectifier DC-DC device. The low-power inverter and the high-power rectifier DC-DC device are connected in parallel. The output end of the low-power inverter is electrically connected to a charging circuit switch, the other end of which is electrically connected to the second armature winding 42. The output end of the high-power rectifier DC-DC device is electrically connected to a discharge circuit switch, the other end of which is electrically connected to the first armature winding 303.
[0032] When the system is charging, a low-power converter or inverter is used to accelerate the rotor core 43. The rotor core 43 drives the flywheel rotor 304 to rotate faster through the rotating shaft 5, thereby storing energy. At this time, the annular excitation winding 302 arranged between the upper and lower sections of the first stator core 301 is not energized, and there is no magnetic field on the flywheel rotor 304. After the second armature winding 42 is charged with low power, when high-power discharge is required, the charging circuit switch can be opened first, and the discharge circuit switch can be closed at the same time. At this time, the annular excitation winding 302 arranged between the upper and lower sections of the first stator core is energized, and a magnetic field is generated on the flywheel rotor 304, which cuts the first armature winding 303 to generate an electromotive force, thereby performing high-power discharge.
[0033] Example 2, please refer to Figure 6-7 This embodiment is further optimized based on the first embodiment, and the same parts as the above technical solutions will not be repeated here. Figure 1-5As shown, in order to better realize the present invention, the following setting is particularly adopted: the connection part between the lower end of the flywheel rotor 304 and the first radial mechanical bearing 6 is a short shaft fixedly connected to the flywheel rotor 304, and the inner bottom wall of the lower casing 1 is fixedly connected to the auxiliary magnetic bearing 9. The auxiliary magnetic bearing 9 includes an auxiliary ferromagnetic ring 91 and an auxiliary bearing excitation winding 92. The bottom of the auxiliary ferromagnetic ring 91 is fixedly connected to the lower casing 1. A magnetic isolation material is provided between the auxiliary ferromagnetic ring 91 and the inner top wall of the lower casing 1. The magnetic isolation material is 304 stainless steel. The area of the magnetic isolation material is greater than or equal to the top surface area of the auxiliary ferromagnetic ring 91. The auxiliary ferromagnetic ring 91 is a groove structure with an opening upward. The auxiliary bearing excitation winding 92 is embedded in the groove of the auxiliary ferromagnetic ring 91. The auxiliary magnetic bearing 9 generates a repulsive force on the flywheel rotor 304 from below. The magnetic bearing 7 and the auxiliary magnetic bearing 9 together offset the weight of the flywheel rotor 304. The output end of the DC bus is electrically connected to a high-power inverter and a low-power rectifier DCDC device. The high-power inverter and the low-power rectifier DCDC device are connected in parallel. The output end of the high-power inverter is electrically connected to a charging circuit switch. The other end of the charging circuit switch is electrically connected to the first armature winding 303. The output end of the low-power rectifier DCDC device is electrically connected to a discharge circuit switch. The other end of the discharge circuit switch is electrically connected to the second armature winding 42.
[0034] When the system is charging, a high-power converter or inverter is used to accelerate the flywheel rotor 304. The flywheel rotor 304 drives the rotor core 43 to rotate faster through the rotating shaft 5, thereby storing energy. At this time, the second armature winding 42 is not energized, and there is no magnetic field on the rotor core 43. After the first armature winding 303 is charged with high power, when low-power discharge is required, the charging circuit switch can be opened first, and the discharge circuit switch can be closed at the same time. At this time, the second armature winding 42 is energized, and a magnetic field is generated on the rotor core 43, which cuts the second armature winding 42 to generate an electromotive force, thereby performing low-power discharge.
[0035] Example 3, please refer to Figure 8 The output end of the DC bus is electrically connected to a small-power inverter and a large-power inverter. The small-power inverter and the large-power inverter are connected in parallel. The output ends of the small-power inverter and the large-power inverter are respectively electrically connected to a first charge-discharge circuit switch and a second charge-discharge circuit switch. The other ends of the first charge-discharge circuit switch and the second charge-discharge circuit switch are respectively electrically connected to the second armature winding 42 and the first armature winding 303. The other ends of the first discharge circuit switch and the second discharge circuit switch are respectively electrically connected to the first armature winding 303 and the second armature winding 42.
[0036] By connecting the first armature winding 303 and the second armature winding 42 to the charging and discharging devices separately, the first armature winding 303 and the second armature winding 42 can be charged at high power and then discharged at high power, or the second armature winding 42 can be charged at low power and then discharged at low power. Cross-charging and discharging are also possible, so that the dual energy channels can be more freely and flexibly matched.
[0037] In summary, the flywheel energy storage device and system with separated electric and power generation adopts the separation of the electric and power generation energy transmission channels of the flywheel energy storage device. The flywheel energy storage control system can flexibly select the energy channel for charging and discharging, expand the application range of the device, and improve the compatibility and stability of the flywheel energy storage system. At the same time, through two sets of armature windings with different powers, an energy channel separated from electric and power generation is formed, reducing armature loss and heat generation, indirectly improving the power and efficiency of the flywheel energy storage device, and increasing the service life of the device. In addition, charging devices of different power levels can be combined with discharge devices of different specifications according to different needs to simplify the design of the flywheel energy storage device. At the same time, a standard mechanical interface is adopted to achieve rapid disassembly and replacement, facilitating maintenance. Therefore, the present application achieves the purpose of separating the electric and power generation energy transmission channels of the flywheel energy storage motor, increasing the diversity of energy channel selection for charging and discharging, reducing the upper limit of loss and heat generation of a single energy channel, indirectly increasing the upper limit of operating power, and enabling the control system to select energy channels with different charging and discharging powers according to different working conditions and motor states. This solves the problem in the prior art that the armature winding used in the electric state and the power generation state is the same, that is, the stator armature winding of the motor, for bidirectional energy transfer. The storage capacity of a flywheel energy storage device mainly depends on the size and speed of the flywheel rotor, and its charging and discharging power depends on the power of the motor. If the motor power cannot be increased due to factors such as size and cost, the charging and discharging power of the flywheel energy storage device, an important indicator, will be directly limited. In some application scenarios that require instantaneous high-power discharge, its important advantages cannot be fully utilized.
[0038] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.
[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A flywheel energy storage device with electric power generation separation, comprising a lower housing (1), the top of the lower housing (1) being fixedly connected to an upper housing (2), the top of the lower housing (1) and the bottom of the upper housing (2) both being provided with through holes, characterized in that: A first stator core (301) is provided inside the lower housing (1). The first stator core (301) is divided into two sections, the upper and lower sections of the first stator core (301) are both annular structures. An annular excitation winding (302) and a first armature winding (303) are sequentially embedded between the upper and lower sections of the first stator core (301) along the center direction from the outside to the inside. The upper and lower sections of the first stator core (301) are both fixedly connected to the inner wall of the lower housing (1). A flywheel rotor (304) placed inside the annular structure of the first stator core (301) is rotatably connected inside the lower housing (1). The flywheel rotor is an iron A magnetic rotor is provided, wherein the upper housing (2) is internally rotatably connected to a rotor core (43), the rotor core (43) is fixedly connected to a flywheel rotor (304) via a rotating shaft (5), the inner bottom wall of the lower housing (1) is fixedly connected to a first radial mechanical bearing (6), the inner top wall of the lower housing (1) is fixedly connected to a magnetic bearing (7), the lower housing (1) is rotatably connected to the flywheel rotor (304) via the first radial mechanical bearing (6), the top of the upper housing (2) is fixedly connected to a second radial mechanical bearing (8), and the upper housing (2) is rotatably connected to the rotating shaft (5) via the second radial mechanical bearing (8).
2. A flywheel energy storage device with electric motor and power generation separation according to claim 1, characterized in that: A second stator core (41) and a second armature winding (42) are fixedly connected inside the upper housing (2); the second stator core (41) is fixedly connected to the upper housing (2); the second armature winding (42) is wound around the outside of the second stator core (41); the rotor core (43) is placed inside the second stator core (41), and the rotor core (43) is fixedly connected to the rotating shaft (5).
3. A flywheel energy storage device with electric motor and power generation separation according to claim 2, characterized in that: The magnetic bearing (7) comprises a ferromagnetic ring (71) and a bearing excitation winding (72); the top of the ferromagnetic ring (71) is fixedly connected to the lower housing (1); a magnetic isolation material is provided between the ferromagnetic ring (71) and the inner top wall of the lower housing (1); the ferromagnetic ring (71) is a groove structure with an opening facing downward; the bearing excitation winding (72) is embedded in the ferromagnetic ring (71); the flywheel rotor (304) is a ferromagnetic rotor, and the flywheel rotor (304) and the magnetic bearing (7) are critically attracted to each other. The ratio of the outer diameter D1 of the ferromagnetic ring (71) to the outer diameter D2 of the flywheel rotor (304) is D1=(0.8-0.9)D2, the ratio of the inner diameter D3 of the ferromagnetic ring (71) to the outer diameter D2 of the flywheel rotor (304) is D3=(0.5-0.6)D2, the ratio of the outer diameter D1 of the ferromagnetic ring (71) to the outer diameter D4 of the second stator core (41) is D1=(10MM-20MM)+D4, and the area of the ferromagnetic ring (71) is less than or equal to the area of the magnetic isolation material.
4. The flywheel energy storage device with electric motor and power generation separation according to claim 1, characterized in that: The lower housing (1) and the upper housing (2) are connected at the stopper, and a vacuum cavity is formed inside the lower housing (1) and the upper housing (2).
5. The flywheel energy storage device with separated electric power generation according to claim 2, characterized in that: The bottom of the rotating shaft (5) is fixedly connected with a boss, the top of the flywheel rotor (304) is provided with a notch adapted to the boss, and the rotating shaft (5) and the flywheel rotor (304) are threadedly connected via the boss and the notch.
6. The flywheel energy storage device with separated electric power generation according to claim 3, characterized in that: The first armature winding (303) and the second armature winding (42) are both provided with a wiring device and are electrically connected to an external power supply. The first armature winding (303) is a three-phase AC winding.
7. The flywheel energy storage device with separated electric power generation according to claim 2, characterized in that: The annular surface of the flywheel rotor (304) is provided with a plurality of regular circular arc grooves, and the number of the circular arc grooves is a multiple of the number of rotor pole pairs.
8. A flywheel energy storage system for separation of electric motor and electric generator according to any one of claims 1 to 7, comprising a DC bus, characterized in that: The output end of the DC bus is electrically connected to a low-power inverter and a high-power rectifier DCDC device, the low-power inverter and the high-power rectifier DCDC device are connected in parallel, the output end of the low-power inverter is electrically connected to a charging circuit switch, the other end of the charging circuit switch is electrically connected to the second armature winding (42), the output end of the high-power rectifier DCDC device is electrically connected to a discharge circuit switch, the other end of the discharge circuit switch is electrically connected to the first armature winding (303).
9. A flywheel energy storage system for separation of electric motor and electric generator according to any one of claims 1 to 7, comprising a DC bus, characterized in that: The output end of the DC bus is electrically connected to a high-power inverter and a low-power rectifier DCDC device, the high-power inverter and the low-power rectifier DCDC device are connected in parallel, the output end of the high-power inverter is electrically connected to a charging circuit switch, the other end of the charging circuit switch is connected to the first armature winding (303), the output end of the low-power rectifier DCDC device is electrically connected to a discharge circuit switch, the other end of the discharge circuit switch is electrically connected to the second armature winding (42).
10. A flywheel energy storage system for separation of electric motor and electric generator according to any one of claims 1 to 7, comprising a DC bus, characterized in that: The output end of the DC bus is electrically connected to a low-power inverter and a high-power inverter, the low-power inverter and the high-power inverter are connected in parallel, the output ends of the low-power inverter and the high-power inverter are electrically connected to a first charge-discharge circuit switch and a second charge-discharge circuit switch, respectively, and the other ends of the first charge-discharge circuit switch and the second charge-discharge circuit switch are electrically connected to the second armature winding (42) and the first armature winding (303), respectively.