A magnetic speed change device and wind power generation system

Abstract

The present invention provides a magnetic speed change device and a wind power generation system, wherein the magnetic speed change device comprises a first magnetic wheel and a second magnetic wheel arranged side by side, the radius of the first magnetic wheel is larger than the radius of the second magnetic wheel, the outer circumferential surface of the first magnetic wheel is covered with a plurality of magnets of the same polarity along the circumferential direction, the outer circumferential surface of the second magnetic wheel is covered with a plurality of magnets of the same polarity as the magnets on the outer circumferential surface of the first magnetic wheel along the circumferential direction, all magnets of the second magnetic wheel have the same size along the outer circumferential direction of the second magnetic wheel, and the size of a single magnet of the first magnetic wheel along the outer circumferential direction of the first magnetic wheel is the same as the size of a single magnet of the second magnetic wheel along the outer circumferential direction of the second magnetic wheel, the number of magnets of the first magnetic wheel is larger than the number of magnets of the second magnetic wheel, and the distance between the two magnets closest to each other on the two magnetic wheels is within the range of the magnetic polarity force of the two magnets. The magnetic speed change device and the wind power generation system provided by the present invention can overcome the shortcomings of the existing speed change gears being easy to wear and having a high failure rate.

Description

Technical Field

[0001] The invention relates to the field of magnetic suspension, and in particular to a magnetic speed change device and a wind power generation system. Background Art

[0002] Wind energy is a clean energy source. It is very environmentally friendly to use wind power to generate electricity. Moreover, the wind energy reserves are huge. With the development of wind power generation technology, wind power generation has also been increasingly valued by countries around the world. At present, there are the following problems in wind power generation: First, conventional variable speed gears are used to increase the speed. The gear failure rate can account for 79% of the failure rate of the entire wind power generation system. Frequent maintenance is required. Moreover, since it is installed at a high place, maintenance is very difficult. In fact, it is difficult to apply it to the wind power generation system. Therefore, the rotation speed of the wind wheel cannot be increased. In order to meet the needs of power generation, the size of the motor needs to be very large, and its own gravity is also very large. The production cost is high and the production difficulty is great. At the same time, the gear meshing will also generate vibration and noise; Second, the start-up of the wind wheel of a high-power wind turbine requires a higher wind speed, and the average wind speed is required to reach 6m / s. However, the average wind speed in more than 85% of my country is 2.5m / s. Therefore, most wind turbines are set up in deserts with strong winds, seas and other areas with abundant wind resources; Third, the bearings of the wind wheel are very easy to be damaged and have a very short service life. Summary of the invention

[0003] The invention provides a magnetic speed change device, which can overcome the shortcomings of the existing speed change gears that are easy to wear and have a high failure rate.

[0004] The magnetic speed change device of the present invention comprises a first magnetic wheel and a second magnetic wheel arranged side by side, the radius of the first magnetic wheel is larger than the radius of the second magnetic wheel, the axis of the first magnetic wheel is parallel to the axis of the second magnetic wheel, the outer circumferential surface of the first magnetic wheel is circumferentially covered with a plurality of magnets of the same polarity, all the magnets of the first magnetic wheel have the same size along the outer circumferential direction of the first magnetic wheel, the outer circumferential surface of the second magnetic wheel is circumferentially covered with a plurality of magnets of the same polarity as the magnets on the outer circumferential surface of the first magnetic wheel, all the magnets of the second magnetic wheel have the same size along the outer circumferential direction of the second magnetic wheel, and the size of a single magnet of the first magnetic wheel along the outer circumferential direction of the first magnetic wheel is the same as the size of a single magnet of the second magnetic wheel along the outer circumferential direction of the second magnetic wheel, the number of magnets of the first magnetic wheel is larger than the number of magnets of the second magnetic wheel, and the distance between the two magnets closest to each other on the two magnetic wheels is within the range of the magnetic polarity force of the two magnets.

[0005] Preferably, the magnet is a permanent magnet.

[0006] Preferably, the axial size of the magnets of the first magnetic wheel is the same as the axial size of the magnets of the second magnetic wheel.

[0007] Preferably, in a direction perpendicular to the axes of the first magnetic wheel and the second magnetic wheel, there is a gap of 1-2 mm between the two magnets closest to each other between the first magnetic wheel and the second magnetic wheel.

[0008] Preferably, the outer circumferential surface of the first magnetic wheel is provided with m magnets, the outer circumferential surface of the second magnetic wheel is provided with n magnets, and 20≥m:n≥2.

[0009] Preferably, m:n=10.

[0010] Preferably, the first magnetic wheel is a driving wheel, and the second magnetic wheel is a driven wheel; or the first magnetic wheel is a driven wheel, and the second magnetic wheel is a driving wheel.

[0011] The present invention also provides a wind power generation system, including a wind wheel and a generator, wherein the wind wheel includes a rotating shaft perpendicular to a horizontal plane and blades fixed on the rotating shaft and capable of rotating synchronously with the rotating shaft, and the wind power generation system also includes a speed change device, wherein the speed change device is a magnetic speed change device as described above, wherein a first magnetic wheel of the magnetic speed change device is fixed on the rotating shaft and capable of rotating synchronously with the rotating shaft, and the second magnetic wheel is fixed on the rotating shaft of the rotor of the generator.

[0012] Preferably, the wind power generation system also includes a permanent magnetic suspension bearing, which includes a stator fixed on a stationary stator bracket and a rotor fixed to the rotating shaft and rotating with the rotating shaft, the rotor includes a hollow disc-shaped first rotor permanent magnet and a hollow disc-shaped second rotor permanent magnet located below the first rotor permanent magnet, the hollowness of the hollow disc is formed by a through hole coaxial with the disc, the stator includes a hollow disc-shaped stator permanent magnet located between the first rotor permanent magnet and the second rotor permanent magnet of the rotor in the up-down direction, and the magnetic pole polarity of the downward end of the first rotor permanent magnet is the same as the magnetic pole polarity of the upward end of the stator permanent magnet, the magnetic pole polarity of the upward end of the second rotor permanent magnet is opposite to the magnetic pole polarity of the downward end of the stator permanent magnet, and the first rotor permanent magnet, the second rotor permanent magnet and the stator permanent magnet are coaxial with the rotating shaft.

[0013] Preferably, the radius of the outer circumference of the first rotor permanent magnet is R1, the radius of the outer circumference of the second rotor permanent magnet is R2, the radius of the outer circumference of the stator permanent magnet is R3, and R2=R3>R1, the radius of the through hole of the first rotor permanent magnet is r1, the radius of the through hole of the second rotor permanent magnet is r2, the outer diameter of the through hole of the stator permanent magnet is r3, and R1>r2=r3>r1.

[0014] Preferably, the rotor further includes a third rotor permanent magnet and a fourth rotor permanent magnet, both of which are annular in shape, the third rotor permanent magnet is fixed above or below the outer circumference of the second rotor permanent magnet, the fourth rotor permanent magnet is fixed above or below the inner circumference of the second rotor permanent magnet, the inner circumference of the second rotor permanent magnet is formed by the inner ring of the through hole of the second rotor permanent magnet, and the polarity of the magnetic poles at the upward ends of the third rotor permanent magnet and the fourth rotor permanent magnet is the same as the polarity of the magnetic poles at the upward end of the second rotor permanent magnet.

[0015] Preferably, a first rotor bracket and a second rotor bracket are fixed to the rotating shaft, the first rotor permanent magnet is fixed to the first rotor bracket, and the third rotor permanent magnet and the fourth rotor permanent magnet are fixed to the second rotor bracket.

[0016] Preferably, the stator bracket, the first rotor bracket and the second rotor bracket are all made of non-magnetic materials.

[0017] Compared with the prior art, the magnetic speed change device and wind power generation system of the present invention have the following beneficial effects:

[0018] 1. The magnetic speed change device of the present invention can replace the gear speed change. When the first magnetic wheel is the driving wheel and the second magnetic wheel is the driven wheel, the magnetic speed change device is a speed increase device. When the first magnetic wheel is the driven wheel and the second magnetic wheel is the driving wheel, the magnetic speed change device is a speed reduction device. The force between the first magnetic wheel and the second magnetic wheel is achieved by the repulsion between the magnetic poles. The two do not need to contact each other, which can avoid the wear and other faults caused by the gear meshing of the ordinary transmission, thereby reducing the failure rate and extending the service life of the speed change device.

[0019] 2. The wind power generation system of the present invention can reduce the starting wind speed of the wind wheel by replacing ordinary bearings with permanent magnetic suspension bearings, so that there are more options for areas where high-power power generation systems can be installed. The present invention improves the structure of the permanent magnetic suspension bearing. The stator permanent magnet applies an upward repulsive force F1 to the first rotor permanent magnet, i.e., the rotor. At the same time, the stator permanent magnet applies an upward attractive force F2 to the second rotor permanent magnet, i.e., the rotor. F1+F2=-G. In this way, the forces of F1 and F2 that need to be provided can be reduced, so a small-volume permanent magnet can do the job.

[0020] 3. The first rotor permanent magnet, the second rotor permanent magnet and the stator permanent magnet of the permanent magnetic suspension bearing are all hollow discs with a through hole in the center. The first rotor permanent magnet, the second rotor permanent magnet and the stator permanent magnet are coaxial with the rotating axis. The radius of the outer circumference of the first rotor permanent magnet 42 is R1, the radius of the outer circumference of the second rotor permanent magnet is, the radius of the outer circumference of the stator permanent magnet is R3, and R2=R3>R1. The radius of the through hole of the first rotor permanent magnet is r1, the radius of the through hole of the second rotor permanent magnet is r2, and the outer diameter of the through hole of the third rotor permanent magnet is r3, and R1>r2=r3>r1. With this arrangement, when the wind wheel is subjected to radial force, the F exerted by the stator permanent magnet on the first rotor permanent magnet 斥 Increase, F 斥 The horizontal force F 斥1 The direction is opposite to the radial external force on the rotating shaft. At the same time, the stator permanent magnet generates a horizontal force F on the second rotor permanent magnet. 吸1 , F 吸1 The direction of the radial force on the rotating shaft is opposite to that of the radial force on the rotating shaft. 斥1 and F 吸1 Together, the two prevent the rotating shaft from moving further, so that the rotating shaft can achieve a more stable state in the radial direction.

[0021] 4. The third rotor permanent magnet of the permanent magnetic suspension bearing is used to strengthen the magnetic field of the second rotor permanent magnet at the outer circumference, and the fourth rotor permanent magnet is used to strengthen the magnetic field of the second rotor permanent magnet at the inner circumference. In this way, when the wind wheel is not subjected to radial force, that is, the stator permanent magnet is aligned with the second rotor permanent magnet, the static magnetic energy at the outer circumference and the inner circumference of the second rotor permanent magnet is lower, so the state of the second rotor permanent magnet is more stable. When the second rotor permanent magnet is staggered with the stator permanent magnet, the static magnetic energy of the second rotor permanent magnet increases, and the stator permanent magnet generates a radial horizontal force F on the second rotor permanent magnet. 吸1 will be larger, so that the rotating shaft can resist greater radial external forces. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a magnetic speed change device according to an embodiment of the present invention.

[0023] Figure 2 It is a schematic structural diagram of a wind power generation system according to an embodiment of the present invention when the rotating shaft is not subjected to radial external force.

[0024] Figure 3 The wind power generation system according to one embodiment of the present invention is a schematic structural diagram of a state in which the rotating shaft is subjected to radial external force.

[0025] Reference numerals

[0026] 11 a first magnetic wheel, 111 a magnet, 12 a second magnetic wheel, 121 a magnet;

[0027] 2 wind wheel, 21 rotating shaft, 22 blades;

[0028] 3 generator, 31 rotor shaft;

[0029] 4 permanent magnetic suspension bearing, 41 stator bracket, 42 first rotor permanent magnet, 43 second rotor permanent magnet, 44 third rotor permanent magnet, 45 fourth rotor permanent magnet, 46 first rotor bracket, 47 second rotor bracket, 48 stator permanent magnet. DETAILED DESCRIPTION

[0030] The present invention provides a magnetic speed change device, the structure of one embodiment of which is as follows Figure 1 As shown, it includes a first magnetic wheel 11 and a second magnetic wheel 12 arranged side by side, the radius of the first magnetic wheel 11 is larger than the radius of the second magnetic wheel 12, the axis of the first magnetic wheel 11 is parallel to the axis of the second magnetic wheel 12, and the outer circumferential surfaces of the first magnetic wheel 11 and the second magnetic wheel 12 are covered with multiple magnets 111 and 121 of the same polarity along their respective circumferential directions, and the magnets 111 on the outer circumferential surface of the first magnetic wheel 11 and the magnets 121 on the outer circumferential surface of the second magnetic wheel 12 are of the same polarity. In this embodiment, the magnets 111, 121 are permanent magnets, all magnets 111 of the first magnetic wheel 11 have the same size along the outer circumferential direction of the first magnetic wheel 11, all magnets 121 of the second magnetic wheel 12 have the same size along the outer circumferential direction of the second magnetic wheel 12, and the size of a single magnet 111 of the first magnetic wheel 11 along the outer circumferential direction of the first magnetic wheel 11 is the same as the size of a single magnet 121 of the second magnetic wheel 12 along the outer circumferential direction of the second magnetic wheel 12, the number of magnets 111 of the first magnetic wheel 11 is greater than the number of magnets 121 of the second magnetic wheel 12, and is within the range of the magnetic polarity force of the two magnets.

[0031] The magnetic speed change device of the present invention can replace the gear speed change. When the first magnetic wheel 11 is the driving wheel and the second magnetic wheel 12 is the driven wheel, the magnetic speed change device is a speed increase device. When the first magnetic wheel 11 is the driven wheel and the second magnetic wheel 12 is the driving wheel, the magnetic speed change device is a speed reduction device. The force between the first magnetic wheel 11 and the second magnetic wheel 12 is achieved by the attraction and repulsion between the magnets 111 and 121. The two do not need to contact each other, which can avoid wear and other faults caused by the gear meshing of the ordinary transmission, thereby reducing the failure rate and extending the service life of the speed change device. At the same time, since the first magnetic wheel 11 and the second magnetic wheel do not need to contact each other, vibration and noise caused by contact can also be avoided.

[0032] In the embodiment, the axial size of a single magnet 111 of the first magnetic wheel 11 is the same as the axial size of a single magnet 121 of the second magnetic wheel 12, and the two ends 111 of the magnet of the first magnetic wheel 11 are respectively aligned with the two ends of the magnet 121 of the second magnetic wheel 12 in the axial direction. In this way, the force between the magnet 111 of the first magnetic wheel 11 and the magnet 121 of the second magnetic wheel 12 can be kept at the maximum. In the direction perpendicular to the axis of the first magnetic wheel 11 and the second magnetic wheel 12, there is a gap of 1-2 mm between the first magnetic wheel 11 and the second magnetic wheel 12, that is, the distance between the two magnets closest to each other on the two magnetic wheels is 1-2 mm.

[0033] Preferably, the outer circumferential wall of the first magnetic wheel 11 is provided with m magnets 111, and the outer circumferential wall of the second magnetic wheel 12 is provided with n magnets 121, where m and n are both positive integers, and 20≥m:n≥2. In this embodiment, m:n=10, such as Figure 1 As shown, m=50, n=5.

[0034] The present invention also provides a wind power generation system, such as Figure 2 As shown, it includes a wind wheel 2 and a generator 3, the wind wheel 2 includes a rotating shaft 21 perpendicular to the horizontal plane, and blades 22 fixed on the rotating shaft 21 and capable of rotating synchronously with the rotating shaft 21. The wind power generation system also includes a speed change device, which is a magnetic speed change device as described above, wherein a first magnetic wheel 11 of the magnetic speed change device is fixed on the rotating shaft 21 and capable of rotating synchronously with the rotating shaft 21, and the second magnetic wheel 12 is fixed on the rotor shaft of the rotor of the generator 3.

[0035] The wind power generation system of the present invention adopts a magnetic speed change device as a speed increaser. When the rotation of the wind wheel 2 is transmitted to the rotor of the motor, the speed is increased several times. The speed of the rotor of the motor is increased several times compared to the case where the speed increaser is not provided. The volume of the generator 3 with the same power can be reduced several times, or the power of the generator 3 with the same volume can be increased several times, thereby improving the power generation capacity of the wind power generation system. At the same time, the force between the first magnetic wheel 11 and the second magnetic wheel 12 of the magnetic speed change device is realized by magnets 111 and 121. The two do not need to contact each other, which can avoid wear and other faults caused by the gear meshing of the ordinary transmission, thereby reducing the failure rate and extending the service life of the speed change device.

[0036] like Figure 2As shown, the wind power generation system further includes a permanent magnetic suspension bearing 4, which includes a stator fixed on a stationary stator bracket 41 and a rotor fixed to the rotating shaft 21 and rotating with the rotating shaft 21, the rotor includes a first rotor permanent magnet 42 and a second rotor permanent magnet 43 located below the first rotor permanent magnet 42, the stator includes a stator permanent magnet 48 located between the first rotor permanent magnet 42 and the second rotor permanent magnet 43 of the rotor in the up-down direction, and the magnetic pole polarity of the downward end of the first rotor permanent magnet 42 is the same as the magnetic pole polarity of the upward end of the stator permanent magnet 48, and in this embodiment, both are N poles. The magnetic pole polarity of the upward end of the second rotor permanent magnet 43 is opposite to the magnetic pole polarity of the downward end of the stator permanent magnet 48. In this embodiment, the magnetic pole polarity of the upward end of the second rotor permanent magnet 43 is N pole, and the magnetic pole polarity of the downward end of the stator permanent magnet 48 is S pole.

[0037] By replacing ordinary bearings with permanent magnetic suspension bearings 4, the starting wind speed of the wind wheel 2 can be reduced, so that the area where a high-power power generation system can be set up has more options. When the rotating shaft is not subjected to axial external force, the force state of the existing wind wheel 2 is, F1 = -|F2+G|, F1 is an upward repulsive force, F2 is a downward repulsive force, and G is the gravity of the wind wheel 2. In this way, the upward repulsive force F1 that needs to be provided will be relatively large. The present invention improves the structure of the permanent magnetic suspension bearing 4, and the stator permanent magnet 48 applies an upward repulsive force F1 to the first rotor permanent magnet 42, that is, the rotor, and at the same time, the stator permanent magnet 48 applies an upward suction force F2 to the second rotor permanent magnet 43, that is, the rotor. When the rotating shaft is not subjected to axial external force, F1+F2=-G, so that the force required to provide smaller F1 and F2 can be reduced, so a small volume of permanent magnets can do the job. If permanent magnets of the same volume are used, the rotating shaft can load a wind wheel of greater weight and withstand a greater axial downward external force.

[0038] like Figure 2 As shown, the first rotor permanent magnet 42, the second rotor permanent magnet 43 and the stator permanent magnet 48 are all hollow discs, and the hollowness is formed by a through hole coaxial with the disc. The first rotor permanent magnet 42, the second rotor permanent magnet 43 and the stator permanent magnet 48 are coaxial with the rotating shaft 21. The radius of the outer circumference of the first rotor permanent magnet 42 is R1, the radius of the outer circumference of the second rotor permanent magnet 43 is R2, the radius of the outer circumference of the stator permanent magnet 44 is R3, and R2=R3>R1. The radius of the through hole of the first rotor permanent magnet 42 is r1, the radius of the through hole of the second rotor permanent magnet 43 is r2, the outer diameter of the through hole of the stator permanent magnet 44 is r3, and R1>r2=r3>r1.

[0039] When the wind wheel 2 is not subjected to radial force, the forces on the first rotor permanent magnet 42 and the second rotor permanent magnet 43 are as follows: Figure 2 As shown, at this time, the repulsive force exerted by the stator permanent magnet 48 on the first rotor permanent magnet 42 makes the first rotor permanent magnet 42 in a balanced state, and the stator permanent magnet 48 is aligned with the second rotor permanent magnet 43. At this time, the static magnetic energy of the second rotor permanent magnet 43 is in the lowest state, that is, the most stable state. When the wind wheel 2 is subjected to radial force, for example, when the rotating shaft 21 is Figure 2 Move left to Figure 3 When the first rotor permanent magnet 42 is in the position shown, the first rotor permanent magnet 42 is close to the stator permanent magnet 48, and the stator permanent magnet 48 exerts a force F on the first rotor permanent magnet 42. 斥 Increase, F 斥 The decomposed rightward horizontal force F 斥1 Also increases, F 斥1 The direction of the radial force is opposite to the direction of the radial external force on the rotating shaft, preventing the rotating shaft 21 from moving further to the left. Figure 3 As shown, the second rotor permanent magnet 43 is staggered with the stator permanent magnet 48, the static magnetic energy of the second rotor permanent magnet 43 increases, and the stator permanent magnet 48 generates a horizontal force F on the right side of the radial diagram on the second rotor permanent magnet 43 吸1 , F 吸1 The direction of the radial force is opposite to the direction of the radial external force on the rotating shaft, and the rotating shaft 21 is prevented from moving further to the left. Therefore, the rotating shaft 21 can obtain a more stable state in the radial direction. When the radial force on the rotating shaft 21 disappears, the rotating shaft 21 returns to the Figure 2 Position shown.

[0040] like Figure 2 and Figure 3As shown, the rotor also includes a third rotor permanent magnet 44 and a fourth rotor permanent magnet 45, both of which are annular. The third rotor permanent magnet 44 is fixed above or below the outer circumference of the second rotor permanent magnet 43, and the fourth rotor permanent magnet 45 is fixed above or below the inner circumference of the second rotor permanent magnet 43. The inner circumference of the third rotor permanent magnet 44 is formed by the inner ring of the through hole of the second rotor permanent magnet 43. The polarity of the magnetic poles of the third rotor permanent magnet 44 and the fourth rotor permanent magnet 45 facing upward is the same as the polarity of the magnetic poles of the second rotor permanent magnet 43 facing upward. The third rotor permanent magnet 44 is used to strengthen the magnetic field of the second rotor permanent magnet 43 at the outer circumference, and the fourth rotor permanent magnet 45 is used to strengthen the magnetic field of the second rotor permanent magnet 43 at the inner circumference. In this way, when the wind wheel 2 is not subjected to radial force, that is, the stator permanent magnet 48 is aligned with the second rotor permanent magnet 43, the static magnetic energy at the outer circumference and the inner circumference of the second rotor permanent magnet 43 is lower, so the state of the second rotor permanent magnet 43 is more stable. When the second rotor permanent magnet 43 is staggered with the stator permanent magnet 48, the static magnetic energy of the second rotor permanent magnet 43 increases, and the stator permanent magnet 48 generates a radial horizontal force F on the second rotor permanent magnet 43. 吸1 will be larger, so that the rotating shaft 21 can resist a larger radial external force.

[0041] In this embodiment, if Figure 2 and Figure 3 As shown, the outer circumferential surface of the third rotor permanent magnet 44 is aligned with the outer circumferential surface of the second rotor permanent magnet, and the inner annular surface of the fourth rotor permanent magnet 45 is aligned with the inner annular surface of the second rotor permanent magnet 43. The magnetic pole polarity of the third rotor permanent magnet 44 and the fourth rotor permanent magnet 45 facing upward is N pole, and the third rotor permanent magnet 44 and the fourth rotor permanent magnet 45 are both fixed below the second rotor permanent magnet 43. The rotating shaft 21 is fixed with a first rotor bracket and a second rotor bracket, the first rotor permanent magnet 42 is fixed to the first rotor bracket, and the third rotor permanent magnet 44 and the fourth rotor permanent magnet 45 are fixed to the second rotor bracket. The stator bracket 41, the first rotor bracket and the second rotor bracket are all made of non-magnetic materials, which have no effect on the magnetic field of the permanent magnet. In this embodiment, the non-magnetic material is stainless steel.

[0042] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Various modifications or equivalent substitutions made by those skilled in the art to the present invention within the essence and protection scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A wind power generation system, characterized in that: The invention comprises a wind wheel and a generator, wherein the wind wheel comprises a rotating shaft perpendicular to a horizontal plane and blades fixed on the rotating shaft and capable of rotating synchronously with the rotating shaft; the wind power generation system further comprises a magnetic speed change device, wherein the magnetic speed change device comprises a first magnetic wheel and a second magnetic wheel arranged side by side, wherein the radius of the first magnetic wheel is greater than the radius of the second magnetic wheel, the axis of the first magnetic wheel is parallel to the axis of the second magnetic wheel, the outer circumferential surface of the first magnetic wheel is covered with a plurality of magnets of the same polarity along the circumferential direction, all magnets of the first magnetic wheel have the same size along the outer circumferential direction of the first magnetic wheel, the outer circumferential surface of the second magnetic wheel is covered with a plurality of magnets of the same polarity as the magnets on the outer circumferential surface of the first magnetic wheel along the circumferential direction, all magnets of the second magnetic wheel have the same size along the outer circumferential direction of the second magnetic wheel, and the size of a single magnet of the first magnetic wheel along the outer circumferential direction of the first magnetic wheel is the same as the size of a single magnet of the second magnetic wheel along the outer circumferential direction of the second magnetic wheel, the number of magnets of the first magnetic wheel is greater than the number of magnets of the second magnetic wheel, and the distance between the two magnets closest to each other on the two magnetic wheels is within the magnetic polarity of the two magnets. Within the force range, the first magnetic wheel of the magnetic speed change device is fixed on the rotating shaft and can rotate synchronously with the rotating shaft, and the second magnetic wheel is fixed on the rotating shaft of the rotor of the generator; the wind power generation system also includes a permanent magnetic suspension bearing, the permanent magnetic suspension bearing includes a stator fixed on a stationary stator bracket and a rotor fixed to the rotating shaft and rotating with the rotating shaft, the rotor includes a hollow disc-shaped first rotor permanent magnet and a hollow disc-shaped second rotor permanent magnet located below the first rotor permanent magnet, the hollow The disc-shaped hollow is formed by a through hole coaxial with the disc, and the stator includes a hollow disc-shaped stator permanent magnet located between the first rotor permanent magnet and the second rotor permanent magnet of the rotor in the up-down direction, and the magnetic pole polarity of the downward end of the first rotor permanent magnet is the same as the magnetic pole polarity of the upward end of the stator permanent magnet, and the magnetic pole polarity of the upward end of the second rotor permanent magnet is opposite to the magnetic pole polarity of the downward end of the stator permanent magnet, and the first rotor permanent magnet, the second rotor permanent magnet and the stator permanent magnet are coaxial with the rotating axis.

2. The wind power generation system according to claim 1, characterized in that: The magnet is a permanent magnet.

3. The wind power generation system according to claim 1, characterized in that: The size of the magnets of the first magnet wheel in the axial direction is the same as the size of the magnets of the second magnet wheel in the axial direction.

4. The wind power generation system according to claim 1, characterized in that: In a direction perpendicular to the axes of the first magnetic wheel and the second magnetic wheel, there is a gap of 1-2 mm between two magnets closest to each other between the first magnetic wheel and the second magnetic wheel.

5. The wind power generation system according to claim 1, characterized in that: The outer circumferential surface of the first magnetic wheel is provided with m magnets, the outer circumferential surface of the second magnetic wheel is provided with n magnets, and 20≥m:n≥2.

6. The wind power generation system according to claim 5, characterized in that: m:n=10.

7. The wind power generation system according to claim 1, characterized in that: The first magnetic wheel is a driving wheel, and the second magnetic wheel is a driven wheel; or the first magnetic wheel is a driven wheel, and the second magnetic wheel is a driving wheel.

8. The wind power generation system according to any one of claims 1 to 7, characterized in that: The radius of the outer circumference of the first rotor permanent magnet is R1, the radius of the outer circumference of the second rotor permanent magnet is R2, the radius of the outer circumference of the stator permanent magnet is R3, and R2=R3>R1, the radius of the through hole of the first rotor permanent magnet is r1, the radius of the through hole of the second rotor permanent magnet is r2, the outer diameter of the through hole of the stator permanent magnet is r3, and R1>r2=r3>r1.

9. The wind power generation system according to claim 8, characterized in that: The rotor also includes a third rotor permanent magnet and a fourth rotor permanent magnet, both of which are annular, the third rotor permanent magnet is fixed above or below the outer circumference of the second rotor permanent magnet, the fourth rotor permanent magnet is fixed above or below the inner circumference of the second rotor permanent magnet, the inner circumference of the second rotor permanent magnet is formed by the inner ring of the through hole of the second rotor permanent magnet, and the polarity of the magnetic poles of the third rotor permanent magnet and the fourth rotor permanent magnet facing upward is the same as the polarity of the magnetic poles of the second rotor permanent magnet facing upward.

10. The wind power generation system according to claim 9, characterized in that: The rotating shaft is fixed with a first rotor bracket and a second rotor bracket, the first rotor permanent magnet is fixed to the first rotor bracket, and the third rotor permanent magnet and the fourth rotor permanent magnet are fixed to the second rotor bracket.

11. The wind power generation system according to claim 10, characterized in that: The stator bracket, the first rotor bracket and the second rotor bracket are all made of non-magnetic materials.

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