[0028] The specific embodiments of the present invention will be further described below in conjunction with the drawings.
[0029] Such as figure 1 As shown, the present invention includes a vacuum container 1, a rotating shaft 2, a permanent magnet radial bearing 3, a flywheel 4, a single-winding outer rotor magnetic levitation switched reluctance motor 5, a permanent magnet unloading bearing 6, and a permanent magnet bias radial-axial magnetic Bearing 7. The permanent magnetic radial bearing 3 is nested on the upper end of the rotating shaft 2 and functions as a spare bearing. A flywheel 4, a single-winding outer rotor magnetic levitation switched reluctance motor 5, and a permanent magnet bias radial-axial magnetic bearing 7 are sequentially fitted on the lower end of the rotating shaft. The flywheel 4 is fixedly connected to the outer rotor of the single-winding outer rotor magnetic levitation switched reluctance motor. The permanent magnet unloading shaft 6 is installed between the lower end of the flywheel 4 and the vacuum container 1, and is used to unload most of the axial weight of the flywheel shaft. The permanent magnet bias radial-axial magnetic bearing 7 at the lower end of the rotating shaft 2 cooperates with the permanent magnet unloading bearing to overcome the residual weight and dynamic load of the flywheel rotating shaft, ensuring stable axial suspension, and providing radial two-degree-of-freedom suspension support of the rotating shaft. The single-winding outer rotor magnetic levitation switched reluctance motor 5 completes the levitation and motor/generator functions of the other two degrees of freedom in the radial direction, and realizes a five-degree-of-freedom fully levitation flywheel energy storage device.
[0030] Such as figure 2 As shown, the single-winding outer rotor magnetic levitation switched reluctance motor 5 used in the present invention is a three-phase 12/8-pole outer rotor, inner stator double convex structure, located in the permanent magnet bias radial-axial magnetic bearing 7 and permanent magnet The radial bearings 3 include a rotor 501, a stator 502, and a winding 503. The stator 502 is inside the rotor 501, and the two are concentric and coaxial. The rotor 501 is fixedly connected to the flywheel 4, and the flywheel 4 is fixedly connected to the rotating shaft 2. The shaft 2 passes through the center of the flywheel. A radial air gap is left between the motor rotor 501 and the stator 502. The winding 503 is superimposed on the motor stator 502, taking phase A as an example, where winding A 1 , A 2 , A 3 , A 4 Form A phase torque/suspension winding, apply current i respectively a1 , I a2 , I a3 , I a4 , Where i a1 = I ma1 +i sa1 , I a2 = I ma2 +i sa2 , I a3 = I ma3 +i sa3 , I a4 = I ma4 +i sa4. i a1 Component i ma1 For the torque current, according to the principle of minimum reluctance, that is, the magnetic flux always closes along the path with the least reluctance, pulling the rotor 501 to rotate. i a1 Component i sa1 Is the floating current, by adjusting i sa1 , I sa2 , I sa3 , I sa4 The size of the single-winding outer rotor magnetic levitation switched reluctance motor 5 achieves two degrees of freedom levitation in the radial direction. Winding B 1 , B 2 , B 3 , B 4 Form B-phase torque/suspension winding. Winding C 1 , C 2 , C 3 , C 4 It constitutes the C-phase torque/suspension winding, with a total of 3 phases. Each set of windings can provide both electric torque and rotor suspension. B 1 , C 1 Located in A 1 30° and 60° clockwise, B 2 , C 2 Located in A 2 30° and 60° clockwise, B 3 , C 3 Located in A 3 30° and 60° clockwise. B 4 , C 4 Located in A 4 30° and 60° clockwise. Each set of windings is independently controlled and can provide torque and suspension force at the same time. When the rotor 501 rotates, it directly drives the fixed flywheel 4 to realize energy storage.
[0031] Such as image 3 As shown, the permanent magnetic unloading bearing 6 used in the present invention includes: an upper magnetic ring 601, a lower magnetic ring 602, and a silicon steel sheet 603. The magnetic ring material generally adopts but is not limited to rare earth material neodymium iron boron material. Silicon steel sheets 603 are attached to both sides of the upper magnetic ring 601 to fix the flywheel 4, which can rotate together with the flywheel 4. Silicon steel sheets 603 are attached to both sides of the lower magnetic ring 602 to fix the vacuum container 1. The upper magnetic ring 601 and the lower magnetic ring 602 adopt but are not limited to axial magnetization, and the magnetization directions are opposite. The repulsive force between the two magnetic rings is used to achieve axial weight unloading. It should be noted that in order to obtain greater rigidity and bearing capacity, the present invention adopts multiple pairs of magnetic rings for axial superposition. Silicon steel sheets are pasted on both sides of the magnetic rings, and the magnetic flux is concentrated in the radial flow in the silicon steel sheets to increase the radial magnetic field. Flux density reduces magnetic flux leakage.
[0032] Such as Figure 4 As shown, the permanent magnetic radial bearing 3 used in the present invention is located at the upper end of the rotating shaft 2 and includes an inner magnetic ring 301, a silicon steel sheet 302, an inner ring pressing plate 303, an outer ring pressing plate 304, and an outer magnetic ring 305. The inner magnetic ring 301 is fixedly connected to the inner ring pressing plate 303, the inner ring pressing plate 303 is fixedly connected to the rotating shaft 2, and the inner magnetic ring 301 can rotate together with the rotating shaft 2. The outer magnetic ring 301 is fixedly connected to the outer ring pressing plate 304, and the outer ring pressing plate 304 is fixedly connected to the vacuum container 1. The magnetic ring material generally adopts but is not limited to rare earth material neodymium iron boron. The outer magnetic ring 305 and the inner magnetic ring 301 are generally but not limited to axial magnetization. The magnetization directions are opposite, and the repulsive force between the two magnetic rings is used to fix the rotating shaft 2 in a balanced position. Both concentric coaxial length. It should be noted that silicon steel sheets and silicon steel sheets 302 are attached to both sides of the magnetic ring, and the magnetic flux concentrates radially in the silicon steel sheets to increase the radial magnetic flux density and reduce the magnetic leakage.
[0033] Such as Figure 5 As shown, the permanent magnet radial bearing used in the present invention has a permanent magnet bias radial-axial 7 located at the lower end of the shaft 2, and includes an axial stator 701, an axial control coil 702, a bearing rotor 705, and a radial control coil 706. Axial control coil 702, radial stator 707, permanent magnet ring 708. The axial stator 701 is fixedly connected to the vacuum container 1, and the two axial control coils 702 are fixedly connected to the axial stator 701. The radial stators 707 are evenly distributed along the circumference at 90 degrees, and each radial stator 707 is overlapped with the radial control coil 706. The permanent magnet ring 708 is radially magnetized and embedded at the junction of the axial stator 701 and the radial stator 707. A radial air gap 704 is left between the bearing rotor 705 and the radial stator 707. The bearing rotor 705 and the axial stator 701 are separated An axial air gap 703 is left between. In the axial control coil 702, two coils that are respectively opposed to each other in the radial direction are connected in series as control coils with related degrees of freedom. The windings of the two axial control coils 702 and the four radial control coils 706 are all energized with direct current. The axial stator 701 and the radial stator 707 are made of laminated silicon steel sheets, and the permanent magnet ring 708 is generally made of but not limited to rare earth material neodymium iron boron, and is magnetized radially. When both the radial direction and the axial direction are stably suspended, the rotating shaft 2 is in the middle position of the suspension under the suction force of the static magnetic field generated by the permanent magnet ring 708.
[0034] Image 6 Is the magnetic circuit diagram of the axial magnetic bearing, in the figure Φ PM Is the static bias flux generated by the permanent magnet ring 708, Φ ZEm It is the control magnetic flux generated by the current in the axial control coil 702, and the air gap magnetic flux is composed of these two parts of magnetic flux. When the axial suspension is stable, the magnetic bearing rotor is in the middle position of the suspension under the static magnetic field attraction generated by the permanent magnet, which is also called the reference position. Due to the symmetry of the structure, the magnetic flux generated by the permanent magnet is in the air gap Z on the right side of the rotor 1 And the air gap Z on the left side of the rotor 2 The positions are equal, and the left and right suctions are equal at this time. If the rotor is subjected to a rightward disturbance force at this equilibrium position, the rotor will deviate from the reference position and move to the right, resulting in the change of the magnetic flux between the left and right air gaps generated by the permanent magnet (assuming the radial direction is at the equilibrium position), that is, the left The air gap increases, so that the magnetic flux generated by the permanent magnet Φ PMz2 Reduce, the air gap on the right side is reduced, so that the magnetic flux produced by the permanent magnet Φ PMz1 increase. Due to the external disturbance force, the rotor moves to the right. At this time, the sensor detects the displacement of the rotor from its reference position. The controller converts this displacement signal into a control signal, and the power amplifier converts this control signal into a control current. The electromagnetic flux Φ is generated in the iron core through the electromagnet coil winding ZEM , Z on the left side of the rotor 2 The flow direction of the excitation magnetic flux and the permanent magnetic flux is the same, which is the same as the permanent magnetic flux Φ PMz2 Superimposed so that the air gap Z 2 The total magnetic flux increases at Φ z2 =Φ PMz2 +Φ ZEM; Excitation flux Φ ZEM On the right air gap Z 2 , Due to the permanent magnetic flux Φ PMz1 Flow in the opposite direction, so in the air gap Z 1 The total magnetic flux reduction at Φz1=Φ PMz1 -Φ ZEM. Therefore, regardless of whether the rotor is disturbed in the positive or negative Z direction, the permanent magnet bias axial magnetic bearing system with negative position feedback, the rotor controls the current in the field winding through the controller to adjust the left and right air gap magnetic flux The size can always keep the rotor in a balanced position.
[0035] Figure 7 It is the magnetic circuit diagram of the radial magnetic bearing, the figure shows the path of the magnetic flux in the X direction, Φ PM Is the static bias flux generated by the permanent magnet ring (708), Φ XEM It is the control magnetic flux in the X direction. The same method can be used to mark the path of the magnetic flux in the Y direction. The principle of radial suspension is the same as that of axial suspension.
[0036] The invention relates to a new type of flywheel energy storage. A permanent magnetic radial bearing is installed on the upper end of the rotating shaft 2 of the flywheel energy storage device, which replaces the mechanical backup bearing in the traditional flywheel device, and can solve the problem of energy loss caused by bearing friction. When the magnetic suspension motor is normal When working, the permanent magnet bearing can be used as a spare bearing to share the radial load of the motor; when the motor is not working, it can be used as a two-degree-of-freedom radial bearing to achieve two-degree-of-freedom suspension of the rotating shaft. The permanent magnetic unloading bearing 6 is fixedly connected to the flywheel 4 and the vacuum container 1 to realize the axial weight unloading of the flywheel energy storage system. The lower end of the shaft adopts a permanent magnet biased radial-axial magnetic bearing to overcome the residual weight and dynamic load of the flywheel shaft to ensure the stable axial suspension of the flywheel shaft. At the same time, it provides the flywheel shaft radial two-degree-of-freedom suspension support, single-winding outer rotor magnetic levitation switch magnet The outer rotor of the resistance motor 5 can directly drive the flywheel, eliminating the need for mechanical transmission, and realizes high-speed rotation and energy storage with compact structure; each set of windings is independently controlled, in addition to electric/generator functions, and can provide radial two-degree-of-freedom suspension force. The invention utilizes the single-winding outer rotor magnetic levitation switched reluctance motor to directly drive the flywheel characteristics and high-speed self-suspension function, organically combines the permanent magnetic axial bearing, permanent magnetic radial bearing and hybrid magnetic bearing strong unloading controllable levitation characteristics to realize the flywheel Five degrees of freedom, low loss, highly reliable suspension, and increase the running speed of the flywheel, reduce system power consumption and volume.
[0037] The present invention has been described above in conjunction with specific implementation steps. However, for those skilled in the art, various improvements and modifications can be made to the present invention without departing from the spirit and scope of the present invention. Therefore, various improvements and modifications that fall within the scope of the claims of the present invention should all fall within the protection scope of the present invention.
