Flywheel energy storage system and braking method and starting method thereof

Abstract

The invention belongs to the technical field of flywheel energy storage, and discloses a flywheel energy storage system and a braking method and starting method thereof.The motor of the flywheel energy storage system is connected with a rotating shaft, a plurality of rotor permanent magnets are evenly arranged on the side wall of a rotor in the circumferential direction of the rotor, one end of each rotor permanent magnet is connected with the rotor, and the other end of each rotor permanent magnet extends towards the inner wall of a shell; a plurality of first electromagnets are arranged at the positions, opposite to the side wall of the rotor, of the shell and are uniformly distributed in the circumferential direction of the rotor; all the first electromagnets are connected to a first electromagnet controller, and the first electromagnet controller is used for controlling the first electromagnets to generate magnetism or lose magnetism; the net distance between the projections of every two adjacent first electromagnets on the side wall of the rotor is larger than the length of the projection of a single rotor permanent magnet on the side wall of the rotor. The flywheel energy storage system is braked in a non-contact mode through magnetic force, the failure situation is not prone to occurring, and reliability is high.

Description

Technical Field

[0001] The invention belongs to the technical field of flywheel energy storage, and in particular relates to a flywheel energy storage system and a braking method and a starting method thereof. Background Art

[0002] As a new type of energy storage technology, flywheel energy storage technology has the advantages of no pollution, fast charge and discharge response speed, and long life. It is widely used in the fields of power grid peak and frequency regulation, uninterruptible power supply, subway braking energy recovery, etc. The braking system is the guarantee of the safe operation of the flywheel energy storage system. As the flywheel moves towards a higher speed range, the braking system design of the high-speed flywheel rotor is particularly important. At present, flywheel braking relies on friction braking, which is a contact braking method. When braking under high-speed operating conditions of the flywheel, this contact braking method will cause the braking system to wear quickly, the surface of the contact part of the braking system will heat up quickly, and the braking failure is prone to occur. The reliability is not very high. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a flywheel energy storage system and a braking method and a starting method thereof. The present invention uses magnetic force to perform non-contact braking on the flywheel energy storage system, which is not prone to failure and has high reliability.

[0004] To achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a flywheel energy storage system, comprising a shell and a motor, wherein a rotor assembly is arranged in the shell, wherein the rotor assembly comprises a rotating shaft and a rotor arranged on the rotating shaft, wherein the motor is connected to the rotating shaft, and the rotating shaft is rotatably connected to the shell, and a plurality of rotor permanent magnets are evenly arranged on the side wall of the rotor along the circumference of the rotor, wherein one end of the rotor permanent magnet is connected to the rotor and the other end extends toward the inner wall of the shell; a plurality of first electromagnets are arranged on the shell at a position opposite to the rotor side wall, and the plurality of first electromagnets are evenly distributed along the circumference of the rotor; all the first electromagnets are connected to a first electromagnet controller, and the first electromagnet controller is used to control the first electromagnets to generate magnetism or lose magnetism; and a net distance between the projections of two adjacent first electromagnets on the rotor side wall is greater than the length of the projection of a single rotor permanent magnet on the rotor side wall.

[0005] Preferably, the side wall of the rotating shaft is evenly provided with a plurality of rotating shaft permanent magnets in the circumferential direction of the rotating shaft, the N poles or S poles of all the rotating shaft permanent magnets point to the inside of the rotating shaft, and a plurality of second electromagnets are provided at positions opposite to the side wall of the rotating shaft on the shell, and all the second electromagnets are connected to a second electromagnet controller, and the second electromagnet controller is used to control the second electromagnet to generate magnetism or lose magnetism; when the second electromagnet controller controls the second electromagnet to generate magnetism, the N poles or S poles of all the second electromagnets point to the inside of the rotating shaft.

[0006] Preferably, the N poles or S poles of all the permanent magnets of the rotating shaft point to the central axis of the rotating shaft and are perpendicular to the central axis of the rotating shaft; When the second electromagnet controller controls the second electromagnet to generate magnetism, the N poles or S poles of all the second electromagnets point to the central axis of the rotating shaft and are perpendicular to the central axis of the rotating shaft.

[0007] Preferably, along the circumferential direction of the rotor, two adjacent rotor permanent magnets have the same poles adjacent to each other or the different poles adjacent to each other.

[0008] Preferably, the rotor permanent magnet is a bar permanent magnet or an arc permanent magnet, the first electromagnet is a bar electromagnet or an arc electromagnet, and the magnetic axis of the rotor permanent magnet is non-perpendicular to the magnetic axis of the first electromagnet.

[0009] Preferably, the number of the rotor permanent magnets is the same as the number of the first electromagnets.

[0010] Preferably, the lower end of the rotating shaft is rotatably connected to the bottom of the shell, the upper end of the rotating shaft passes through the upper end of the shell and is rotatably and sealingly connected to the upper end of the shell, and the upper end of the rotating shaft located outside the shell is connected to the motor.

[0011] Preferably, all the rotor permanent magnets are distributed in a rotationally symmetrical manner in the circumferential direction of the rotor; and all the first electromagnets are distributed in a rotationally symmetrical manner in the circumferential direction of the rotor.

[0012] In a second aspect, the present invention provides a braking method for the above-mentioned flywheel energy storage system, comprising the following process: For any first electromagnet, when the first electromagnet loses contact with the projection of the rotor permanent magnet moving away from the first electromagnet on the rotor side wall, the first electromagnet controller is used to control the first electromagnet to generate magnetism, and under the action of the magnetic field generated by the first electromagnet, the first electromagnet and the rotor permanent magnet moving toward the first electromagnet repel each other to decelerate the rotor; when the first electromagnet and the projection of the rotor permanent magnet moving toward the first electromagnet on the rotor side wall begin to overlap, the first electromagnet controller is used to control the first electromagnet to lose magnetism; Repeat the above process until the shaft stops rotating.

[0013] In a third aspect, the present invention provides a method for starting the flywheel energy storage system, comprising the following steps: The motor drives the rotating shaft to rotate, and when the rotating shaft rotates, the first electromagnet controller controls the first electromagnet to generate magnetism to assist in accelerating the rotor; The process of controlling the first electromagnet to generate magnetism through the first electromagnet controller to assist in accelerating the rotor includes: for any first electromagnet, when the first electromagnet loses contact with the projection of the rotor permanent magnet moving away from the first electromagnet on the rotor side wall, controlling the first electromagnet to generate magnetism through the first electromagnet controller, and under the action of the magnetic field generated by the first electromagnet, the first electromagnet and the rotor permanent magnet moving toward the first electromagnet attract each other to accelerate the rotor; when the first electromagnet and the projection of the rotor permanent magnet moving toward the first electromagnet on the rotor side wall begin to overlap, controlling the first electromagnet to lose magnetism through the first electromagnet controller; repeating the above process until the rotor reaches a preset speed, and then controlling the first electromagnet to lose magnetism through the first electromagnet controller.

[0014] The present invention has the following beneficial effects: The flywheel energy storage system of the present invention has a plurality of rotor permanent magnets evenly arranged on the side wall of the rotor along the circumference of the rotor, and a plurality of first electromagnets are evenly arranged on the housing at positions opposite to the side wall of the rotor, and the plurality of first electromagnets are evenly distributed along the circumference of the rotor. A first electromagnet controller for controlling the first electromagnet to generate magnetism or lose magnetism is also provided. When the flywheel energy storage system needs to brake, due to the large moment of inertia of the rotor, the rotor generally rotates for a period of time before stopping. In this process, the rotor can be braked in the following manner: the first electromagnet controller controls the first electromagnet to generate magnetism to decelerate the rotor; In the process of decelerating the rotor: for any first electromagnet, when the first electromagnet is out of contact with the projection of the rotor permanent magnet moving away from the first electromagnet on the rotor side wall, the first electromagnet controller controls the first electromagnet to generate magnetism, and under the action of the magnetic field generated by the first electromagnet, the first electromagnet and the rotor permanent magnet moving toward the first electromagnet repel each other to decelerate the rotor; when the first electromagnet and the projection of the rotor permanent magnet moving toward the first electromagnet on the rotor side wall begin to overlap, the first electromagnet controller controls the first electromagnet to lose magnetism; repeat the above process until the shaft stops rotating. In the above process, the magnetic field can generate a torque opposite to the direction of rotation of the rotor, so that the speed of the rotor is reduced until it stops. It can be seen that the present invention can brake the flywheel energy storage system in a non-contact manner. At the same time, the present invention installs the rotor permanent magnet for braking on the rotor side wall and the first electromagnet on the housing at a position opposite to the rotor side wall. Since the diameter of the rotor is larger relative to the shaft, compared with the traditional braking force applied to the shaft, the present invention has a larger force arm during braking, and the required braking force is relatively small, and the braking effect is better. At the same time, it can be seen from the above content that the present invention uses the magnetic force between the first electromagnet and the rotor permanent magnet to brake the rotor. This braking method is a non-contact braking method, thereby avoiding the situation where the braking temperature is high and the braking failure occurs during transmission friction braking. Therefore, the reliability of the flywheel energy storage system of the present invention during braking is high. In addition, during the startup phase, the flywheel energy storage system of the present invention needs to use a motor to directly drive the shaft to rotate, and then drive the rotor to rotate for energy storage. However, during the initial startup phase, due to the large inertia of the rotor, the torque requirement for the motor is high during startup, and the rotor speed rises slowly, so the required startup time is relatively long.The flywheel energy storage system of the present invention can also assist the motor in starting during the startup phase. Specifically, when the motor drives the shaft to rotate, the first electromagnet controller controls the first electromagnet to generate magnetism to accelerate the rotor. In the process of accelerating the rotor: for any first electromagnet, when the first electromagnet is out of contact with the projection of the rotor permanent magnet moving away from the first electromagnet on the rotor side wall, the first electromagnet controller controls the first electromagnet to generate magnetism. Under the action of the magnetic field generated by the first electromagnet, the first electromagnet and the rotor permanent magnet moving toward the first electromagnet attract each other to accelerate the rotor; when the first electromagnet and the projection of the rotor permanent magnet moving toward the first electromagnet on the rotor side wall begin to overlap, the first electromagnet controller controls the first electromagnet to lose magnetism; repeat the above process until the rotor reaches a preset speed, and the first electromagnet controller controls the first electromagnet to lose magnetism. It can be seen that the flywheel energy storage system of the present invention can use the first electromagnet and the rotor permanent magnet to achieve braking, and can also assist in starting and speed up the acceleration process of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A longitudinal section view of a flywheel energy storage system in an embodiment of the present invention; Figure 2 Schematic diagram of the rotor assembly structure of the flywheel energy storage system in an embodiment of the present invention; Figure 3 It is a top view of the flywheel energy storage system (housing not shown) in the embodiment of the present invention during the normal charging and discharging process, wherein the same poles of two adjacent rotor permanent magnets are adjacent; Figure 4 It is a top view of the flywheel energy storage system (housing not shown) in the embodiment of the present invention during the normal charging and discharging process, wherein the opposite poles of two adjacent rotor permanent magnets are adjacent; Figure 5 It is a top view of the flywheel energy storage system (housing not shown) in an embodiment of the present invention during an emergency braking process, wherein the same poles of two adjacent rotor permanent magnets are adjacent; Figure 6 It is a top view of the flywheel energy storage system (housing not shown) in an embodiment of the present invention during an emergency braking process, wherein the opposite poles of two adjacent rotor permanent magnets are adjacent; Figure 7It is a top view of the flywheel energy storage system (housing not shown) in the embodiment of the present invention when it is started, wherein the same poles of two adjacent rotor permanent magnets are adjacent; Figure 8 It is a top view of the flywheel energy storage system (housing not shown) in the embodiment of the present invention when it is started, wherein the opposite poles of two adjacent rotor permanent magnets are adjacent.

[0017] Among them: 1. Shell; 2. Rotor; 3. Rotating shaft; 4. Rotating shaft permanent magnet; 5. Second electromagnet; 6. Rotor permanent magnet; 601. No. 1 rotor permanent magnet; 602. No. 2 rotor permanent magnet; 7. First electromagnet. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] See also Figure 1-Figure 6 The flywheel energy storage system of this embodiment includes a housing 1 and a motor. A rotor assembly is provided in the housing 1. The rotor assembly includes a rotating shaft 3 and a rotor 2 arranged on the rotating shaft 3. The motor (not shown in the figure) is connected to the rotating shaft 3. The rotating shaft 3 is rotatably connected to the housing 1. A plurality of rotor permanent magnets 6 are evenly provided on the side wall of the rotor 2 along the circumference of the rotor 2. One end of the rotor permanent magnet 6 is connected to the rotor 2 and the other end extends toward the inner wall of the housing 1. That is, one end of the rotor permanent magnet 6 is installed on the rotor 2 and the other end extends into the space between the rotor 2 and the housing 1 so as to generate magnetic force between the rotor permanent magnet 6 and the first electromagnet 7. A plurality of first electromagnets 7 are provided on the housing 1 at a position opposite to the side wall of the rotor 2. The plurality of first electromagnets 7 are evenly distributed along the circumference of the rotor 2. All the first electromagnets 7 are connected to a first electromagnet controller, and the first electromagnet controller is used to control the first electromagnet 7 to generate magnetism or lose magnetism.

[0020] In the above-mentioned embodiment of the present invention, along the circumferential direction of the rotor 2, two adjacent rotor permanent magnets 6 can be arranged to be adjacent to each other with the same poles (see Figure 3 , Figure 5 and Figure 7 ) or opposite poles adjacent (see Figure 4 , Figure 6 and Figure 8 Both of the above forms are acceptable. When the flywheel energy storage system needs to be braked or started, the magnetic poles of the first electromagnet 7 located between two adjacent rotor permanent magnets 6 only need to be adaptively changed. This function can be controlled by the first electromagnet controller, which belongs to conventional technology and is not specifically limited by the present invention.

[0021] See also Figure 3-Figure 6 , the rotation direction of the rotor 2 is counterclockwise. In the following description, the rotor permanent magnet 6 moving away from the first electromagnet 7 is recorded as the first rotor permanent magnet 601, and the rotor permanent magnet 6 moving toward the first electromagnet 7 is recorded as the second rotor permanent magnet 602. The first rotor permanent magnet 601 is adjacent to the second rotor permanent magnet 602. The working principle of the flywheel energy storage system of the above embodiment of the present invention is as follows: When the flywheel energy storage system works normally, the first electromagnet controller controls all first electromagnets 7 to lose magnetism, so that the rotor 2 can rotate normally. Figure 3 and Figure 4 .

[0022] When the flywheel energy storage system needs to brake, the first electromagnet controller controls the first electromagnet 7 to generate magnetism to decelerate the rotor 2. The case where two adjacent rotor permanent magnets have the same poles adjacent to each other is used as an example for explanation. For details, see Figure 5 : For any first electromagnet 7, when the first electromagnet 7 loses contact with the projection of the No. 1 rotor permanent magnet 601 on the side wall of the rotor 2, the first electromagnet 7 is controlled by the first electromagnet controller to generate magnetism. Under the action of the magnetic field generated by the first electromagnet 7, the first electromagnet 7 and the No. 2 rotor permanent magnet 602 repel each other, and the first electromagnet 7 and the No. 1 rotor permanent magnet 601 attract each other, so that a clockwise torque can be applied to the rotor 2, thereby slowing down the rotor 2; when the first electromagnet 7 and the projection of the No. 2 rotor permanent magnet 602 on the side wall of the rotor 2 begin to overlap, the first electromagnet 7 is controlled by the first electromagnet controller to lose its magnetism; the above braking process is repeated until the shaft 3 stops rotating.

[0023] When the flywheel energy storage system needs to brake, the first electromagnet controller controls the first electromagnet 7 to generate magnetism to decelerate the rotor 2. The case where two adjacent rotor permanent magnets have opposite poles and are adjacent to each other is described as an example. For details, see Figure 6: For any first electromagnet 7, when the first electromagnet 7 loses contact with the projection of the first rotor permanent magnet 601 on the side wall of the rotor 2, the first electromagnet controller controls the first electromagnet 7 to generate magnetism. Under the action of the magnetic field generated by the first electromagnet 7, the first electromagnet 7 and the second rotor permanent magnet 602 repel each other, and the first electromagnet 7 and the first rotor permanent magnet 601 attract each other. At this time, although the first electromagnet 7 and the first rotor permanent magnet 601 attract each other, one end of the rotor permanent magnet 6 is connected to the rotor 2 and the other end extends toward the inner wall of the housing 1. Therefore, the force of mutual attraction between the first electromagnet 7 and the No. 1 rotor permanent magnet 601 is much smaller than the force of mutual repulsion between the first electromagnet 7 and the No. 2 rotor permanent magnet 602. Therefore, for the entire rotor 2, the clockwise torque applied by the first electromagnet 7 to the rotor 2 is greater than the counterclockwise torque applied by the first electromagnet 7 to the rotor 2, so the rotor 2 can be decelerated; when the projections of the first electromagnet 7 and the No. 2 rotor permanent magnet 602 on the side wall of the rotor 2 begin to overlap, the first electromagnet 7 is controlled by the first electromagnet controller to lose its magnetism; the above braking process is repeated until the shaft 3 stops rotating.

[0024] When the flywheel energy storage system needs to be started, the motor drives the shaft 3 to rotate. When the shaft 3 rotates, the first electromagnet controller controls the first electromagnet 7 to generate magnetism to assist in accelerating the rotor 2. See also Figure 7 , taking the case where two adjacent rotor permanent magnets have the same poles adjacent to each other as an example for explanation, specifically, the first electromagnet controller controls the first electromagnet 7 to generate magnetism to assist in accelerating the rotor 2: for any first electromagnet 7, when the first electromagnet 7 loses contact with the projection of the No. 1 rotor permanent magnet 601 on the side wall of the rotor 2, the first electromagnet controller controls the first electromagnet 7 to generate magnetism, and under the action of the magnetic field generated by the first electromagnet 7, the first electromagnet 7 and the No. 2 rotor permanent magnet 602 attract each other, and the first electromagnet 7 and the No. 1 rotor permanent magnet 601 repel each other, so that a counterclockwise torque can be applied to the rotor 2, thereby accelerating the rotor 2; when the projections of the first electromagnet 7 and the No. 2 rotor permanent magnet 602 on the side wall of the rotor 2 begin to overlap, the first electromagnet controller controls the first electromagnet 7 to lose magnetism; repeat the above process until the rotor 2 reaches a preset speed, and the first electromagnet controller controls the first electromagnet 7 to lose magnetism.

[0025] See also Figure 8, take the case where two adjacent rotor permanent magnets with opposite poles are adjacent as an example to illustrate, specifically, the first electromagnet controller controls the first electromagnet 7 to generate magnetism to assist in accelerating the rotor 2: for any first electromagnet 7, when the first electromagnet 7 is out of contact with the projection of the first rotor permanent magnet 601 on the side wall of the rotor 2, the first electromagnet controller controls the first electromagnet 7 to generate magnetism, and under the action of the magnetic field generated by the first electromagnet 7, the first electromagnet 7 and the second rotor permanent magnet 602 attract each other, and the first electromagnet 7 and the first rotor permanent magnet 601 attract each other. At this time, although the first electromagnet 7 and the first rotor permanent magnet 601 attract each other, one end of the rotor permanent magnet 6 is attracted to the rotor 2 is connected, and the other end extends toward the inner wall direction of the shell 1. Therefore, the mutual attraction force between the first electromagnet 7 and the first rotor permanent magnet 601 is much smaller than the mutual attraction force between the first electromagnet 7 and the second rotor permanent magnet 602. Therefore, for the entire rotor 2, the clockwise torque applied by the first electromagnet 7 to the rotor 2 is greater than the counterclockwise torque applied by the first electromagnet 7 to the rotor 2, so the rotor 2 can be accelerated; when the projections of the first electromagnet 7 and the second rotor permanent magnet 602 on the side wall of the rotor 2 begin to overlap, the first electromagnet 7 is controlled to lose its magnetism by the first electromagnet controller; the above process is repeated until the rotor 2 reaches a preset speed, and the first electromagnet 7 is controlled to lose its magnetism by the first electromagnet controller.

[0026] In the process of assisting the acceleration of the rotor 2, the preset rotation speed may be set according to actual conditions, and the present invention does not make any specific requirements.

[0027] As a preferred embodiment of the present invention, in this embodiment, the side wall of the rotating shaft 3 is evenly provided with a plurality of rotating shaft permanent magnets 4 in the circumferential direction of the rotating shaft 3, and the N poles or S poles of all rotating shaft permanent magnets 4 point to the inside of the rotating shaft 3. A plurality of second electromagnets 5 are provided at positions on the housing 1 opposite to the side wall of the rotating shaft 3, and all the second electromagnets 5 are connected to a second electromagnet controller, and the second electromagnet controller is used to control the second electromagnet 5 to generate magnetism or lose magnetism; when the second electromagnet controller controls the second electromagnet 5 to generate magnetism, the N poles or S poles of all the second electromagnets 5 point to the inside of the rotating shaft 3. See Figure 3 and Figure 4 When the flywheel energy storage system works normally, the second electromagnet controller controls the second electromagnet 5 to generate magnetism, so that the shaft permanent magnet 4 and the second electromagnet 5 form a mutual repulsion effect, thereby ensuring the stability of the shaft 3. Figure 5 and Figure 6When the flywheel energy storage system needs to brake, the second electromagnet controller controls the second electromagnet 5 to generate magnetism, so that the shaft permanent magnet 4 and the second electromagnet 5 form a mutual attraction. The mutual attraction between the shaft permanent magnet 4 and the second electromagnet 5 can generate a clockwise torque, which can further provide braking force and accelerate the flywheel braking.

[0028] As an optional implementation scheme of the present invention, in this embodiment, the N poles or S poles of all the rotating shaft permanent magnets 4 point to the central axis of the rotating shaft 3 and are perpendicular to the central axis of the rotating shaft 3; when the second electromagnet controller controls the second electromagnet 5 to generate magnetism, the N poles or S poles of all the second electromagnets 5 point to the central axis of the rotating shaft 3 and are perpendicular to the central axis of the rotating shaft 3. Under the above structure, the repulsive force and the attractive force between the rotating shaft permanent magnets 4 can achieve a better matching effect.

[0029] As an optional implementation scheme of the present invention, in this embodiment, the rotor permanent magnet 6 is a bar permanent magnet or an arc permanent magnet, the first electromagnet 7 is a bar electromagnet or an arc electromagnet, and the magnetic axis of the rotor permanent magnet 6 is non-vertical to the magnetic axis of the first electromagnet 7. Those skilled in the art can select according to actual conditions, and the present invention does not make specific limitations. Figure 3-Figure 6 In the illustrated embodiment, the rotor permanent magnet 6 is a bar-shaped permanent magnet, and the first electromagnet 7 is an arc-shaped electromagnet. The magnetic axis of the rotor permanent magnet 6 and the magnetic axis of the first electromagnet 7 are in a non-perpendicular state.

[0030] As an optional implementation scheme of the present invention, in this embodiment, the number of the rotor permanent magnets 6 and the first electromagnets 7 is the same. Figure 6 As shown, in this embodiment, all rotor permanent magnets 6 are distributed in a rotationally symmetrical manner in the circumferential direction of the rotor 2 ; and all first electromagnets 7 are distributed in a rotationally symmetrical manner in the circumferential direction of the rotor 2 .

[0031] In the flywheel energy storage system of the present invention, the lower end of the rotating shaft 3 is rotatably connected to the bottom of the housing 1, the upper end of the rotating shaft 3 passes through the upper end of the housing 1, and is rotatably and sealably connected to the upper end of the housing 1, and the upper end of the rotating shaft 3 located outside the housing 1 is connected to the motor; Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be included in the scope of the present invention.

Claims

1. A flywheel energy storage system, characterized in that: The invention comprises a housing (1) and a motor, wherein a rotor assembly is arranged in the housing (1), wherein the rotor assembly comprises a rotating shaft (3) and a rotor (2) arranged on the rotating shaft (3), wherein the motor is connected to the rotating shaft (3), and the rotating shaft (3) is rotatably connected to the housing (1), wherein a plurality of rotor permanent magnets (6) are evenly arranged on the side wall of the rotor (2) along the circumference of the rotor (2), wherein one end of the rotor permanent magnet (6) is connected to the rotor (2) and the other end extends toward the inner wall of the housing (1); wherein a plurality of first electromagnets (7) are evenly arranged on the housing (1) at a position opposite to the side wall of the rotor (2), and wherein the plurality of first electromagnets (7) are evenly distributed along the circumference of the rotor (2); wherein all the first electromagnets (7) are connected to a first electromagnet controller, and wherein the first electromagnet controller is used to control the first electromagnets (7) to generate magnetism or lose magnetism; and wherein the net distance between the projections of two adjacent first electromagnets (7) on the side wall of the rotor (2) is greater than the length of the projection of a single rotor permanent magnet (6) on the side wall of the rotor (2).

2. A flywheel energy storage system according to claim 1, characterized in that: A plurality of rotating shaft permanent magnets (4) are evenly arranged on the side wall of the rotating shaft (3) in the circumferential direction of the rotating shaft (3); the N poles or S poles of all the rotating shaft permanent magnets (4) point to the interior of the rotating shaft (3); a plurality of second electromagnets (5) are arranged on the housing (1) at positions opposite to the side wall of the rotating shaft (3); all the second electromagnets (5) are connected to a second electromagnet controller; the second electromagnet controller is used to control the second electromagnets (5) to generate magnetism or lose magnetism; when the second electromagnet controller controls the second electromagnets (5) to generate magnetism, the N poles or S poles of all the second electromagnets (5) point to the interior of the rotating shaft (3).

3. A flywheel energy storage system according to claim 2, characterized in that: The N poles or S poles of all the rotating shaft permanent magnets (4) point to the central axis of the rotating shaft (3) and are perpendicular to the central axis of the rotating shaft (3); When the second electromagnet controller controls the second electromagnets (5) to generate magnetism, the N poles or S poles of all the second electromagnets (5) point to the central axis of the rotating shaft (3) and are perpendicular to the central axis of the rotating shaft (3).

4. A flywheel energy storage system according to any one of claims 1 to 3, characterized in that: Along the circumferential direction of the rotor (2), the same poles of two adjacent rotor permanent magnets (6) are adjacent or the different poles are adjacent.

5. A flywheel energy storage system according to any one of claims 1 to 3, characterized in that: The rotor permanent magnet (6) is a bar permanent magnet or an arc permanent magnet, the first electromagnet (7) is a bar electromagnet or an arc electromagnet, and the magnetic axis of the rotor permanent magnet (6) and the magnetic axis of the first electromagnet (7) are in a non-perpendicular state.

6. A flywheel energy storage system according to any one of claims 1 to 3, characterized in that: The number of the rotor permanent magnets (6) and the number of the first electromagnets (7) are the same.

7. A flywheel energy storage system according to any one of claims 1 to 3, characterized in that: The lower end of the rotating shaft (3) is rotatably connected to the bottom of the shell (1), the upper end of the rotating shaft (3) passes through the upper end of the shell (1) and is rotatably and sealingly connected to the upper end of the shell (1), and the portion of the upper end of the rotating shaft (3) located outside the shell (1) is connected to the motor.

8. A flywheel energy storage system according to any one of claims 1 to 3, characterized in that: All rotor permanent magnets (6) are distributed in a rotationally symmetrical manner in the circumferential direction of the rotor (2); All the first electromagnets (7) are distributed in a rotationally symmetrical manner in the circumferential direction of the rotor (2).

9. A braking method for a flywheel energy storage system according to any one of claims 1 to 8, characterized in that: The process includes the following: For any first electromagnet (7), when the first electromagnet (7) loses contact with the projection of the rotor permanent magnet (6) moving away from the first electromagnet (7) on the side wall of the rotor (2), the first electromagnet controller controls the first electromagnet (7) to generate magnetism. Under the action of the magnetic field generated by the first electromagnet (7), the first electromagnet (7) and the rotor permanent magnet (6) moving toward the first electromagnet (7) repel each other, thereby decelerating the rotor (2); when the first electromagnet (7) and the projection of the rotor permanent magnet (6) moving toward the first electromagnet (7) on the side wall of the rotor (2) begin to overlap, the first electromagnet controller controls the first electromagnet (7) to lose magnetism; The above process is repeated until the shaft (3) stops rotating.

10. A method for starting a flywheel energy storage system according to any one of claims 1 to 8, characterized in that: The process includes the following: The rotating shaft (3) is driven to rotate by a motor, and when the rotating shaft (3) rotates, the first electromagnet (7) is controlled by a first electromagnet controller to generate magnetism, so as to assist in accelerating the rotor (2); The process of controlling the first electromagnet (7) to generate magnetism by a first electromagnet controller to assist in accelerating the rotor (2) comprises: for any first electromagnet (7), when the first electromagnet (7) loses contact with the projection of the rotor permanent magnet (6) moving away from the first electromagnet (7) on the side wall of the rotor (2), controlling the first electromagnet (7) to generate magnetism by the first electromagnet controller, and under the action of the magnetic field generated by the first electromagnet (7), the first electromagnet (7) and the rotor permanent magnet (6) moving toward the first electromagnet (7) attract each other to accelerate the rotor (2); when the first electromagnet (7) and the projection of the rotor permanent magnet (6) moving toward the first electromagnet (7) on the side wall of the rotor (2) begin to overlap, controlling the first electromagnet (7) to lose magnetism by the first electromagnet controller; repeating the above process until the rotor (2) reaches a preset speed, controlling the first electromagnet (7) to lose magnetism by the first electromagnet controller.

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