CN110165821B

CN110165821B - Horizontal self-vacuumizing chamber high-integration flywheel energy storage device

Info

Publication number: CN110165821B
Application number: CN201910384604.3A
Authority: CN
Inventors: 张维煜; 杨启富; 程烨东; 朱熀秋
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2019-05-09
Filing date: 2019-05-09
Publication date: 2021-04-20
Anticipated expiration: 2039-05-09
Also published as: CN110165821A

Abstract

The invention discloses a high-integration flywheel energy storage device of a horizontal self-vacuumizing chamber, wherein a vacuum cavity is formed by a shell, and the upper end in the vacuum cavity is a three-degree-of-freedom magnetic bearing fixedly connected with the shell through a bracket, and the three-degree-of-freedom magnetic bearing comprises a radial magnetic bearing, an axial magnetic bearing and a permanent magnet; the lower end of the three-degree-of-freedom magnetic bearing is a flywheel rotor, the single-winding outer rotor bearingless motor is positioned at the lower end of the flywheel rotor, the rotor of the single-winding outer rotor bearingless motor is embedded in an annular groove on the lower surface of the flywheel rotor, and the stator of the single-winding outer rotor bearingless motor is fixed at the lower end of the shell through the bracket, so that five-degree-of-freedom balance of the flywheel rotor is realized by matching the three-degree-of-freedom magnetic; the upper end of the shell is provided with a horizontal compound vacuum pump which is of a double-rotor structure with mirror symmetry left and right, so that the vacuum degree and the pumping speed are improved.

Description

Horizontal self-vacuumizing chamber high-integration flywheel energy storage device

Technical Field

The invention relates to the technical field of flywheel energy storage, in particular to a flywheel energy storage device which realizes five-degree-of-freedom balance by matching a three-degree-of-freedom magnetic bearing with a single-winding outer rotor bearingless motor and adopts a horizontal vacuum pump to perform self-vacuumizing.

Background

With the rapid development of global economy, the consumption of natural resources is increasingly intensified, and people face the major problems of the exhaustion of natural resources and environmental pollution, so that people seek new environmental-friendly and clean energy and pay more attention to how to more effectively utilize the existing energy and actively develop an advanced energy storage technology. The traditional chemical storage battery has high energy storage density and low price, is widely adopted, but has the advantages of regular maintenance, short service life, large energy loss, long charging time and environmental pollution. Because the flywheel energy storage system has the advantages of high specific energy, long service life, high efficiency, no pollution and the like, the adoption of the flywheel energy storage system for energy storage becomes an important means for green sustainable development.

The traditional flywheel energy storage system adopts a five-degree-of-freedom magnetic bearing to support a flywheel rotor, one axial magnetic bearing unit controls axial single degree of freedom, and two radial magnetic bearing units respectively control two degrees of freedom at the upper end and the lower end of the rotor. The flywheel energy storage system supported by the five-degree-of-freedom magnetic bearing effectively solves the problem of friction between a rotor and a bearing, but due to the complexity of the system structure, a plurality of inherent problems still exist, for example, due to the fact that a plurality of magnetic bearing units are needed to support the rotor, the flywheel energy storage system is large in size, long in axial direction and low in system critical rotating speed, and further improvement of the flywheel rotating speed and power is limited.

In addition, at present, an external vertical vacuum system is generally adopted for vacuumizing the flywheel energy storage system at home and abroad, so that the air pumping speed is low and the difficulty is relatively high. The prior art relates to a composite molecular pump combining a first-stage turbo molecular pump and a traction molecular pump, wherein a clearance blade of the turbo molecular pump is cancelled to be made into a continuous blade of a pump rotor, so that the fault caused by the falling of the blade due to large centrifugal force is reduced, however, the vacuum pump with the structure has fewer turbine stages, the requirement of the device on the pumping speed at an ideal vacuum side cannot be met, the transition process from the turbine stage to the traction stage is shorter, the improvement of the pumping speed and the compression ratio is influenced, and the requirement of a high-vacuum high-performance flywheel energy storage system cannot be met; the vertical structure also increases the gravity center of the flywheel energy storage system, which is not beneficial to the reliable operation of the system; in addition, the single pump rotor is adopted for vacuumizing, so that the vacuumizing speed is not optimistic, and energy is not saved.

Therefore, a flywheel energy storage system with high integration level, which has a simple structure, is convenient to control, is low in price, has high energy storage density, and is pumped by a vacuum pump with stable and reliable operation and high pumping speed, is urgently needed.

Disclosure of Invention

The invention aims to overcome the defects of low integration level, complex control and low energy storage density of the traditional flywheel energy storage device, provides the flywheel energy storage device of the motor without the bearing by matching the three-degree-of-freedom magnetic bearing with the single-winding outer rotor, simplifies the structure and the control mode of the flywheel energy storage device, improves the integration level and the energy storage density of a flywheel energy storage system, and reduces the cost and the loss. In addition, the invention provides a horizontal double-rotor composite vacuum pump for overcoming the defect of slow pumping speed of the conventional external vacuum system, and the vacuum pumping speed of the vacuum chamber is improved.

The purpose of the invention is realized by adopting the following technical scheme:

a high-integration flywheel energy storage device of a horizontal self-vacuumizing chamber comprises a double-rotor compound vacuum pump, wherein the double-rotor compound vacuum pump is horizontally arranged at the upper end of a shell, a three-degree-of-freedom magnetic bearing, a flywheel rotor and a single-winding outer rotor bearingless motor are sequentially arranged in the shell from top to bottom, the three-degree-of-freedom magnetic bearing and the single-winding outer rotor bearingless motor are respectively fixed with the upper end and the lower end of the inner surface of the shell, a gap is formed between the three-degree-of-freedom magnetic bearing and the flywheel rotor, and the.

In the above scheme, the dual-rotor compound vacuum pump is a dual-rotor structure with two mirror images, and the front stage is a turbine type compound vacuum pump and the rear stage is a traction type compound vacuum pump.

In the above scheme, the dual-rotor compound vacuum pump includes a pump stator and a pump rotor, the pump rotor includes a pump rotor shaft of a symmetrical structure, one end of the pump rotor shaft is in a circular truncated cone shape, preceding turbine moving blades are symmetrically arranged near the middle part of the pump rotor shaft, rear traction spiral blades are symmetrically arranged at two end parts of the pump rotor shaft, the pump stator includes preceding turbine fixed blades, the preceding turbine fixed blades and the preceding turbine moving blades are arranged at intervals, and the preceding turbine fixed blades are fixed on the inner surface of a pump stator housing.

In the scheme, the three-degree-of-freedom magnetic bearing sequentially comprises a radial magnetic bearing, an inner side bias permanent magnet, an inner side axial magnetic bearing, an outer side bias permanent magnet and an outer side axial magnetic bearing from the circle center to the outside along the radial direction.

In the scheme, the radial magnetic bearing comprises a radial magnetic bearing iron core, a round table-shaped boss is arranged in the middle of the radial magnetic bearing iron core, a boss with an L-shaped section is arranged outside the radial magnetic bearing iron core, a gap is arranged between the L-shaped boss and the round table-shaped boss, n openings are uniformly formed in the L-shaped boss, and n is larger than or equal to 3.

In the scheme, n openings are uniformly arranged on the bosses of the iron cores of the inner and outer axial magnetic bearings, the openings of the bosses of the iron cores of the inner and outer axial magnetic bearings are radially positioned on the same straight line, and n is more than or equal to 3.

In the scheme, the upper surface of the flywheel disc of the flywheel rotor is provided with the annular boss, the annular boss is in clearance fit with the L-shaped boss and the round table-shaped boss, and the lower surface of the flywheel disc is provided with the annular groove.

In the scheme, the rotor of the single-winding outer rotor bearingless motor is embedded in the annular groove.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention breaks through the limitation of the traditional flywheel energy storage device adopting a shaft design, adopts a shaftless design, realizes the integration of the motor and the flywheel, reduces the axial length of a flywheel energy storage system, and improves the integration level, the space utilization rate and the energy storage density of the system.

2. The invention breaks through the control mode of the traditional flywheel battery by adopting a five-degree-of-freedom magnetic bearing, realizes five-degree-of-freedom balance by adopting a mode of matching one three-degree-of-freedom magnetic bearing with a single-winding outer rotor bearingless motor, realizes radial two-degree-of-freedom control by utilizing the bearingless motor, reduces the axial size of the flywheel battery, breaks through the limitation of higher rotating speed and high power while maintaining the advantages of the five-degree-of-freedom magnetic bearing support, fundamentally changes the structure and control of the traditional flywheel energy storage system, and widens the application range of the flywheel energy storage.

3. The vacuum environment of the invention is realized by a horizontal double-rotor compound vacuum pump, the horizontal pump blade is arranged on a horizontal shaft, the stage number of a turbine is fully increased, the transition process from the turbine stage to the traction stage is improved, the air suction speed and the compression ratio are improved, an air inlet is positioned in the middle of the pump, air is sucked by two sides of the double rotors, the compound pump rotors on the two sides are coaxially connected, the air can be dragged by a motor, the energy is saved, and the air suction speed can reach 2 times of that of a vertical pump at the highest under the condition that the geometric dimension and the rotating speed of the rotor blade are the same.

Drawings

FIG. 1 is a perspective sectional view of the present invention;

FIG. 2 is a three-dimensional block diagram of the base of the housing;

FIG. 3 is a front view of the internal structure of a horizontal type double-rotor compound vacuum pump;

FIG. 4 is a three-dimensional structural view of a rotor of the horizontal type double-rotor compound vacuum pump;

FIG. 5 is a bottom view of a three-degree-of-freedom magnetic bearing;

FIG. 6 is a cross-sectional view of a three-dimensional structure of a three-degree-of-freedom magnetic bearing;

FIG. 7 is a three-dimensional block diagram of a three-degree-of-freedom magnetic bearing carrier;

FIG. 8 is a cross-sectional view of a three-dimensional structure of a flywheel rotor;

FIG. 9 is a three-dimensional structural sectional view of a stator bracket of a single-winding outer rotor bearingless motor;

FIG. 10 is a top view of a single winding outer rotor bearingless motor;

FIG. 11 is a schematic diagram of the bias flux generated by permanent magnets in a three degree of freedom magnetic bearing of the present invention;

FIG. 12 is a schematic diagram of an axial magnetic bearing implementing axial single degree of freedom balance control in operation of the present invention;

FIG. 13 is a schematic diagram of a radial magnetic bearing implementing radial two-degree-of-freedom balance control during operation of the present invention;

FIG. 14 is a schematic diagram of a radial two-degree-of-freedom balance control of a single-winding outer rotor bearingless motor during operation of the present invention.

In the figure: 1. a housing; 11. an upper end cover; 111. a central hole of the upper end cover; 12. a housing body; 13. a lower end cover; 2. a support base; 21. a base support; 22. a limiting hole; 3. a horizontal double-rotor compound vacuum pump; 31. a vacuum pump stator; 311. a vacuum pump stator housing; 312. an air outlet of the vacuum pump; 313. a vacuum pump inlet; 314. a preceding stage turbine fixed blade; 32. a vacuum pump rotor; 321. a vacuum pump rotating shaft; 322. a preceding stage turbine moving blade; 323. a rear stage traction helical blade; 33. a vacuum pump bracket; 4. a bracket; 41-43 spokes; 44. a central disc; 5. a three-degree-of-freedom magnetic bearing; 51. a radial magnetic bearing; 511. a radial magnetic bearing core; 512. a radial magnetic bearing control coil; 52. an axial magnetic bearing; 521. an axial magnetic bearing core; 522. an axial magnetic bearing control coil; 53. biasing the permanent magnet; 531. an inboard biased permanent magnet; 532. an outer bias permanent magnet; 6. a flywheel rotor; 61. a flywheel disc; 62. an annular boss is arranged at the upper end of the flywheel disc; 63. the lower end of the flywheel disc is provided with an annular groove; 7. a single-winding outer rotor bearingless motor; 71. a single-winding outer rotor bearingless motor stator; 72. a single-winding outer rotor bearingless motor rotor; 73. a single-winding outer rotor bearingless motor stator winding; 8. and (4) a bracket.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1, the energy storage device of the present invention has a cavity formed by a housing 1, the housing is composed of an upper end cap 11, a housing body 12 and a lower end cap 13, the upper end of the housing body 12 is tightly and fixedly connected with the upper end cap 11, and the lower end of the housing body 12 is tightly and fixedly connected with the lower end cap 13. The center of the upper end cover 11 is provided with a central hole 111, and the molecular pump pumps air in the cavity through the small hole, so that a vacuum environment is formed in the cavity. The shell 1 is supported by a shell supporting base 2 at the lower end of the shell, the shell supporting base 2 is composed of a base support 21 and six limiting holes 22, and the upper end face of the base support 21 is tightly and fixedly connected with the lower surface of the shell lower end cover 13. The structure of the housing support base 2 is shown in fig. 2, and the limiting hole 22 is used for fixedly connecting the energy storage device with other components.

The vacuum chamber of the invention is realized by a horizontal type double-rotor compound vacuum pump 3, the horizontal type double-rotor compound vacuum pump 3 is a double-rotor structure with mirror symmetry at the left side and the right side, the left side and the right side are both compound vacuum pumps with turbine type front stages and traction type rear stages, and the vacuum chamber is composed of a pump stator 31, a pump rotor 32 and a pump supporting frame 33, the pump supporting frame 33 is positioned at the lower end of the pump stator 31 and is connected with the pump stator 31 into a whole, the lower surface of the pump supporting frame 33 is tightly connected with an upper end cover 11 of a shell, and the pump rotor 32 is positioned inside the pump stator 31. Referring to fig. 3, the pump stator 31 is composed of a cylindrical pump stator housing 311, left and right air outlets 312, air inlets 313, left and right front stage turbine stator blades 314, the air outlets 312 are arranged at the lower ends of the two sides of the cylindrical pump stator housing 311, the air inlets 313 are arranged at the bottom end of the pump stator housing 311, and the air inlets 313 are coaxially and tightly connected with the central hole 111 of the upper end cover; the pump rotor 32 is composed of a pump rotor shaft 321, left and right front stage turbine moving blades 322 and left and right rear stage traction spiral blades 323, the three-dimensional structure diagram of the pump rotor 32 is shown in fig. 4, the pump rotor shaft 321 is fixedly connected with the left and right sides of the pump stator housing 311 through bearings, the pump rotor shaft 321 is of a symmetrical structure, one end of the pump rotor shaft is in a circular truncated cone shape, the front stage turbine moving blades 322 are symmetrically arranged at the middle part close to the pump rotor shaft 321, and the rear stage traction spiral blades 323 are symmetrically arranged at the two end parts of the pump rotor shaft 321; the front turbine stator blade 314 and the front turbine rotor blade 322 are arranged at an interval, and the front turbine stator blade 314 is fixed to the inner surface of the pump stator casing 311.

The inner surface of the upper end cover 11 is fixed with a bracket 4 (figure 7), the center of the bracket 4 is a central disk 44, three

spokes

41, 42 and 43 with 120 degrees intervals radially extend outwards by taking the axis of the central disk 44 as the center, the tail ends of the spokes are annular bosses which are coaxial with the central disk 44, the side surfaces of the bosses are tightly connected with the shell body 12, and the upper surface of the bosses is tightly connected with the upper end cover 11. The lower surface of the bracket 4 is tightly connected with the upper surface of the three-degree-of-freedom magnetic bearing 5, and the

spokes

41, 42, 43 are respectively staggered 60 degrees with the opening of the L-shaped boss of the iron core of the three-degree-of-freedom magnetic bearing, and the radius of the spokes is larger than that of the control coil 522 of the outer axial magnetic bearing, as shown in fig. 5 and 6.

As shown in fig. 5, the three-degree-of-freedom magnetic bearing 5 is composed of a radial magnetic bearing 51, an axial magnetic bearing 52 and a bias permanent magnet 53, which are coaxially arranged, and the upper surfaces of the three are the same plane, and the whole is a disk structure. Fig. 5 and 6 are bottom and cross-sectional views of the three-degree-of-freedom magnetic bearing 5, in which a radial magnetic bearing 51, an inner bias permanent magnet 531, an inner axial magnetic bearing, an outer bias permanent magnet 532, and an outer axial magnetic bearing are sequentially arranged from the center of a circle radially outward. Referring to fig. 5 and 6, the radial magnetic bearing 51 is composed of a radial magnetic bearing core 511 and radial magnetic bearing control coils 512, a table-shaped boss is arranged in the middle of the radial magnetic bearing core 511, a boss with an L-shaped cross section is arranged outwards, a gap is arranged between the L-shaped boss and the table-shaped boss, an opening with an angle of 10 degrees is formed at intervals of 120 degrees on the L-shaped boss, and three groups of radial magnetic bearing control coils 512 are respectively wound on the three L-shaped bosses. The axial magnetic bearing 52 is composed of an inner axial magnetic bearing iron core 521, an outer axial magnetic bearing iron core 521 and inner and outer axial magnetic bearing control coils 522, wherein the bosses of the inner and outer axial magnetic bearing iron cores 521 are opened with an opening of 10 degrees at intervals of 120 degrees, and the inner and outer sets of axial magnetic bearing control coils 522 are respectively wound on the three bosses of the inner and outer axial magnetic bearing iron cores. Preferably, the openings between the L-shaped bosses, the openings between the inner axial magnetic bearing core bosses, and the openings between the outer axial magnetic bearing core bosses are radially positioned on the same straight line. The inner side bias permanent magnet 531 and the outer side bias permanent magnet 532 are both in circular ring structures and are both radially magnetized; the inner biased permanent magnet 531 is located between the inner axial magnetic bearing core and the radial magnetic bearing core 511, and the outer biased permanent magnet 532 is located between the inner axial magnetic bearing core and the inner axial magnetic bearing core.

The flywheel rotor 6 is positioned at the lower end of the three-degree-of-freedom magnetic bearing 5, a gap is arranged between the flywheel rotor 6 and the three-degree-of-freedom magnetic bearing 5, and a gap is also arranged between the flywheel rotor 6 and the shell body 12.

Fig. 8 is a cross-sectional view of the flywheel rotor 6, a coaxial annular boss 62 is provided on the upper surface of the flywheel disc 61, and the boss 62 and the radial magnetic bearing 51 are in clearance fit with each other between the L-shaped boss and the circular table-shaped boss to realize radial control of the flywheel. The lower surface of the flywheel disc 61 is provided with a coaxial annular groove 63 for embedding a rotor 71 of the single-winding outer rotor bearingless motor, the radius of the inner surface of the annular groove 63 is smaller than that of the inner surface of the bracket 8, and an air gap between the rotor 71 of the single-winding outer rotor bearingless motor, a stator 72 of the single-winding outer rotor bearingless motor and the bracket 8 is provided, as shown in fig. 1.

The structure of the bracket 8 is shown in fig. 9, the bracket 8 is annular, the cross section is L-shaped, and the single-winding outer rotor bearingless motor stator 72 is fixed on the bracket 8. Fig. 10 is a cross-sectional top view of the single-winding outer rotor bearingless motor 7, an outer side surface of the motor rotor 71 is tightly connected with an outer side surface of the annular groove 63, the motor stator 72 is located inside the motor rotor 71, the motor stator 72 is wound with a stator winding 73, when three-phase alternating current is introduced into the motor stator winding 73, a magnetic field generated in an air gap between the motor stator 72 and the motor rotor 71 interacts with the motor rotor 71 to generate radial suspension force and circumferential rotation torque, so that the motor rotor 71 drives the flywheel rotor 6 to rotate, and energy storage is realized.

When the invention works, the unilateral static suspension and five-freedom-degree balance of the flywheel rotor 6 can be realized. In the aspect of axial control, direct current is supplied to the inner and outer axial magnetic bearing control coils 522 of the three-degree-of-freedom magnetic bearing 5, the inner and outer axial magnetic bearing control coils and the inner and outer axial magnetic bearing iron cores 521 form an electromagnet, and the size and direction of axial stress of the flywheel rotor 6 are changed by changing the size and direction of the control direct current, so that control over one degree of freedom of the flywheel rotor in the axial direction is realized. In the aspect of radial control, direct current is supplied to a radial magnetic bearing control coil 512 of the three-degree-of-freedom magnetic bearing 5, and the direct current and a radial magnetic bearing iron core 511 form an electromagnet, so that the magnitude and the direction of resultant force borne by the annular boss 62 at the upper end of the flywheel disc are changed by changing the magnitude and the direction of the control direct current, and the control of two radial translational degrees of freedom at the upper end of the flywheel rotor is realized; the lower end of the flywheel disc is provided with a single-winding outer rotor bearingless motor 7, and the axial rotation of the flywheel rotor and the control of two radial translation degrees of freedom at the lower end of the flywheel rotor can be realized by controlling three-phase alternating current introduced into a stator winding coil 73. Finally, five-degree-of-freedom balance of the flywheel rotor 6 is achieved through the cooperation of the three-degree-of-freedom magnetic bearing 5 and the single-winding outer rotor bearingless motor. When the flywheel rotor 6 is normally operated, the pump rotor 32 of the vacuum pump 3 rotates at a high speed, and gas molecules collide with the surface of the preceding stage turbine moving blades 322 rotating at a high speed to obtain momentum, and generate a directional flow under the interaction between the preceding stage turbine moving blades 322 and the preceding stage turbine fixed blades 314, and are discharged to both sides toward the rear stage trailing spiral blades 323 of the vacuum pump. The turbine blade in the vacuum pump 3 near the middle is longer, the pumping area is larger, and the pumping speed is high, so that clean ultrahigh vacuum can be obtained. The lengths of the turbine moving blades 322 and the turbine fixed blades 314 are gradually reduced from the middle to the two sides, and meanwhile, the gas molecules are discharged to a traction stage through natural transition by utilizing the characteristic that the radius of the rotor shaft 321 of the circular truncated cone-shaped pump is gradually increased. Gas molecules are compressed to two ends of the pump rotor along a spiral groove channel between the vacuum pump stator shell 311 and the pump rotor shaft 321 under the action of the pump rotor shaft 321 and the rear-stage traction spiral blade 323, and are exhausted to the atmosphere from the left and right gas outlets 312. Because the depth of the spiral groove is relatively shallow, the air extraction area is small, the compression ratio is large, and the pumping speed can be doubled by adopting the double rotors for pumping vacuum. The method comprises the following specific steps:

realizing single-side static suspension balance: referring to fig. 11, the bias magnetic fluxes generated by the inner bias permanent magnet 531 and the outer bias permanent magnet 532 are as shown by dotted lines and arrows in the figure, the magnetic flux generated by the inner bias permanent magnet 531 starts from an inner surface N pole of the inner bias permanent magnet 531, a part of the magnetic flux passes through an outer L-shaped boss of the radial magnetic bearing iron core 511, passes through an outer radial air gap of the annular boss 62 at the upper end of the flywheel disc, then passes through the boss 62, the flywheel disc 61, the axial air gap, the inner axial magnetic bearing iron core, and finally returns to an outer surface S pole of the inner bias permanent magnet 531; the other part passes through the middle boss of the radial magnetic bearing iron core 511, passes through the inner radial air gap of the annular boss 62 at the upper end of the flywheel disc, then passes through the boss 62, the flywheel disc 61, the axial air gap, the inner axial magnetic bearing iron core and finally returns to the S pole of the inner bias permanent magnet 531. The bias flux generated by the outer bias permanent magnet 532 passes through the outer axial magnetic bearing core, the axial air gap, the flywheel disc 61, the axial air gap, the inner axial magnetic bearing core in sequence from the N pole of the outer bias permanent magnet 532 and finally returns to the S pole of the outer bias permanent magnet 532. When the flywheel rotor 6 is not disturbed, the axial air gap magnetic flux between the inner and outer axial magnetic bearing iron cores 521 and the flywheel disc 61 generates upward attraction force to the flywheel rotor 6 to balance the gravity borne by the flywheel rotor 6, the forces generated by the radial air gap magnetic flux inside and outside the annular boss 62 at the upper end of the flywheel disc are also balanced, and the central axes of the flywheel rotor 6 and the three-degree-of-freedom magnetic bearing 5 are superposed, so that the single-side static suspension balance of the flywheel rotor is realized.

The balance of one degree of freedom in the axial direction is realized: referring to fig. 12, when the flywheel rotor is shifted downward by the axial disturbance, the control coil 522 of the axial magnetic bearing is energized, and the generated magnetic flux is shown by the solid line and the arrow in fig. 12, and the magnetic flux is superimposed with the axial air gap magnetic flux between the inner and outer axial magnetic bearing cores and the flywheel disk 61, so that the upward attractive force of the axial magnetic bearing 52 on the flywheel rotor 6 is increased, and the flywheel rotor 6 is moved upward and returns to the equilibrium position. Conversely, when the flywheel rotor 6 is disturbed upwardly, the axial air gap flux is cancelled, the upward attraction of the flywheel rotor 6 by the axial magnetic bearing 52 is reduced, and the flywheel rotor 6 moves downwardly and returns to its equilibrium position.

Magnetic bearing radial two-degree-of-freedom: referring to fig. 13, a A, B, C coordinate system is established in the radial plane, when the flywheel rotor 6 is disturbed in the radial direction and shifted to the B direction, the radial magnetic bearing control coil 512 is energized, and the generated magnetic flux is shown by the solid line and the arrow in fig. 13, and the magnetic flux is superimposed with the radial air gap magnetic flux outside the boss 62 at the upper end of the flywheel disc and cancelled with the radial air gap magnetic flux inside the boss 62, so that the resultant force exerted on the boss 62 points to the radial inward direction, i.e. the reverse direction of B, and the flywheel rotor 6 moves in the reverse direction of B and returns to the equilibrium position. Similarly, the radial magnetic bearing 51 can also return the flywheel rotor 6 to the equilibrium position when disturbed in the directions a and C.

The radial two-degree-of-freedom balance of the single-winding outer rotor bearingless motor is realized: referring to fig. 14, a set of windings 73 is added to the stator teeth of the single-winding outer rotor bearingless motor 7, and the current of each tooth winding is controlled independently. Coordinate systems in two directions of alpha and beta are established in a radial plane, taking the phase A as an example, A1, A2, A3 and A4 in FIG. 14 respectively represent windings on four teeth of the phase A. When the flywheel rotor 6 is subjected to radial disturbance and deviates to the alpha direction, the currents in the windings A1 and A3 are controlled, namely the current in the winding A1 is increased, and the current in the winding A3 is reduced, so that the resultant force applied to the single-winding outer rotor bearingless motor rotor 71 points to the opposite direction of the alpha, the motor rotor 71 drives the flywheel to move to the opposite direction of the alpha and return to the balance position, and the disturbance in the beta direction is similar. The other B-phase and C-phase principles are similar to the control mode of the A-phase, a three-phase alternate conduction mode is adopted, the current in each phase winding is tracked in real time by establishing a mathematical model, the amplitude and the direction of the synthetic magnetic pull force acting on the rotor can be changed by adjusting the relative magnitude of the current, and the radial two-degree-of-freedom balance of the motor is realized.

The present invention can be realized in light of the above. Other variations and modifications which may occur to those skilled in the art without departing from the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

1. A horizontal self-vacuumizing chamber high-integration flywheel energy storage device is characterized by comprising a double-rotor compound vacuum pump (3), wherein the double-rotor compound vacuum pump (3) is horizontally arranged at the upper end of a shell (1), a three-degree-of-freedom magnetic bearing (5), a flywheel rotor (6) and a single-winding outer rotor bearingless motor (7) are sequentially arranged in the shell (1) from top to bottom, the three-degree-of-freedom magnetic bearing (5) and the single-winding outer rotor bearingless motor (7) are respectively fixed with the upper end and the lower end of the inner surface of the shell (1), a gap is arranged between the three-degree-of-freedom magnetic bearing (5) and the flywheel rotor (6), and the single-winding outer rotor bearingless motor;

the three-degree-of-freedom magnetic bearing (5) is sequentially provided with a radial magnetic bearing (51), an inner side bias permanent magnet (531), an inner side axial magnetic bearing, an outer side bias permanent magnet (532) and an outer side axial magnetic bearing from the circle center to the outside along the radial direction;

the radial magnetic bearing (51) comprises a radial magnetic bearing iron core (511), a round table-shaped boss is arranged in the middle of the radial magnetic bearing iron core (511), a boss with an L-shaped section is arranged outside the radial magnetic bearing iron core (511), a gap is formed between the L-shaped boss and the round table-shaped boss, n openings are uniformly formed in the L-shaped boss, and n is more than or equal to 3;

the bosses of the iron cores of the inner and outer axial magnetic bearings are uniformly provided with n openings, and the openings of the bosses of the iron cores of the inner and outer axial magnetic bearings are radially positioned on the same straight line;

the upper surface of flywheel rotor (6) flywheel dish (61) is equipped with annular boss (62), clearance fit between annular boss (62) and L shape boss and the round table form boss.

2. The horizontal self-vacuumizing chamber high-integration flywheel energy storage device according to claim 1, wherein the double-rotor compound vacuum pump (3) is a compound vacuum pump having a double-rotor structure with mirror symmetry at two ends, and the front stage is a turbine type and the rear stage is a traction type.

3. The horizontal self-vacuum-pumping chamber high-integration flywheel energy storage device as claimed in claim 2, wherein the dual-rotor compound vacuum pump (3) comprises a pump stator (31) and a pump rotor (32), the pump rotor (32) comprises a pump rotor shaft (321) with a symmetrical structure, one end of the pump rotor shaft (321) is in a circular truncated cone shape, a front turbine moving blade (322) is symmetrically arranged near the middle part of the pump rotor shaft (321), rear traction spiral blades (323) are symmetrically arranged at two end parts of the pump rotor shaft (321), the pump stator (31) comprises a front turbine fixed blade (314), the front turbine fixed blade (314) and the front turbine moving blade (322) are arranged at intervals, and the front turbine fixed blade (314) is fixed on the inner surface of a pump stator housing (311).

4. The horizontal self-vacuumizing chamber high-integration flywheel energy storage device according to claim 1, wherein an annular groove (63) is formed in the lower surface of the flywheel disc (61).

5. The horizontal self-vacuumizing chamber high-integration flywheel energy storage device according to claim 4, wherein the rotor of the single-winding outer rotor bearingless motor (7) is embedded inside the annular groove (63).