Flywheel energy storage motor and use method

Abstract

The invention relates to the technical field of electric energy storage, and provides a flywheel energy storage motor and a use method. The rotor is rotationally connected to the interior of the shell, and magnetic resistance of the rotor is non-uniformly distributed in the circumferential direction of the rotor; the stator is arranged on the outer side of the rotor in a surrounding mode in the circumferential direction of the rotor, and the stator is connected with the shell; a stator coil is connected to one surface, facing the rotor, of the stator and is used for generating a rotating magnetic field capable of rotating around the axis of the rotor; gaps are formed between the stator and the rotor and between the stator coil and the rotor; the two ends, in the axis direction of the rotor, of the rotor are each provided with at least one magnet exciting coil, the magnet exciting coils are connected with the shell, the axes of the magnet exciting coils are parallel to the axis of the rotor, and gaps exist between the magnet exciting coils and the stator. According to the invention, the technical problems of complex structure, high manufacturing cost, poor high-temperature adaptability and great bearing burden caused by mainly adopting a flywheel permanent magnet motor in the existing flywheel energy storage technology can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy storage, and in particular to a flywheel energy storage motor and a use method thereof. Background Art

[0002] Flywheel energy storage motors are widely used in oil drilling, rail transit, power grid frequency modulation, UPS uninterruptible power supply and other scenarios due to their advantages such as high power, fast response, high frequency, high energy density and long life. They play an increasingly important role in power storage and conversion. Among them, permanent magnet motors are widely used in flywheel energy storage due to their high efficiency and no need for excitation. However, permanent magnet motors also have the following disadvantages:

[0003] 1. Since the rotor needs to be embedded with permanent magnets, the motor rotor structure is relatively complex. At high speeds, it is usually necessary to take measures such as external protective covers to protect the permanent magnets to prevent the permanent magnets from disintegrating or being thrown out. In addition, in order to place the permanent magnets, the axial dimension of the permanent magnet motor rotor is usually large, requiring a larger motor space.

[0004] 2. Due to the presence of permanent magnets, the rotor eddy current loss is large, and problems such as rotor heating and high-temperature demagnetization of permanent magnets are particularly prominent.

[0005] 3. In order to store energy, the rotor often has an extremely high speed and mass, which will put a great burden on the bearings at both ends of the rotor; currently, a few flywheel motors use radial magnetic bearings to rotationally position the flywheel rotor to achieve high-speed rotation of the flywheel rotor; however, due to the high cost, large size, and complex control of radial magnetic bearings, they are not widely used.

[0006] In general, the current flywheel permanent magnet motor has a complex structure, high manufacturing cost, poor high temperature adaptability, and a huge burden on the bearings. Therefore, there is an urgent need to develop a flywheel motor with a simpler structure and more reliable operation. Summary of the invention

[0007] The purpose of the present invention is to overcome the technical problems that the existing flywheel energy storage technology mainly adopts a flywheel permanent magnet motor, whose rotor needs to be embedded with permanent magnets, resulting in a complex structure, high manufacturing cost, poor high temperature adaptability, and a great burden on the bearings, and to provide a flywheel energy storage motor and a method of use.

[0008] In a first aspect, the present invention provides a flywheel energy storage motor, comprising:

[0009] case;

[0010] The rotor is rotatably connected to the inside of the housing, and the magnetic resistance of the rotor is unevenly distributed along its circumference;

[0011] The stator is arranged on the outer side of the rotor along the circumferential direction of the rotor, and the stator is connected to the housing; a stator coil is connected to the side of the stator facing the rotor, and the stator coil is used to generate a rotating magnetic field that can rotate around the axis of the rotor; there are gaps between the stator and the rotor, and between the stator coil and the rotor;

[0012] Excitation coil: at least one excitation coil is respectively arranged at both ends of the rotor along the axial direction; the excitation coil is connected to the housing; the axis of the excitation coil is parallel to the axis of the rotor; and there is a gap between the excitation coil and the stator.

[0013] When this scheme is working, current is passed through the stator coil, and a rotating magnetic field rotating around the rotor axis is generated through the stator coil; since the magnetic resistance of the rotor is unevenly distributed along its circumference, the rotor has a minimum magnetic resistance position relative to the rotating magnetic field; based on the minimum magnetic resistance principle, when the rotor is not in the minimum magnetic resistance position, the rotor will be pulled back to the minimum magnetic resistance position by the electromagnetic torque formed by the magnetic pull, so when the magnetic field generated by the stator coil rotates, the rotor can rotate synchronously with the rotating magnetic field to complete the conversion of electrical energy into mechanical energy.

[0014] The excitation coils at both ends of the rotor can generate a magnetic field that passes through the air gap between the rotor and the excitation coils along the axis of the rotor. On the one hand, they can pull the rotor from both ends of the rotor along the axis of the rotor. Therefore, by adjusting the current in the excitation coils at both ends, the resultant force on the rotor along its axis can be changed. By adjusting the resultant force to be opposite to the direction of gravity, part or even all of the rotor's own weight can be offset, thereby greatly reducing the burden on the rotor bearings. On the other hand, the magnetic field generated by the excitation coil can also pass through the stator coil and interact with the magnetic field generated by the stator coil. Therefore, by adjusting the current in the excitation coil, the voltage of the stator coil can be kept stable during charging and discharging.

[0015] At the same time, since the resultant force on the rotor along its axial direction will be affected by many factors such as the air gap size between the rotor and the excitation coil, assembly error, shell residual magnetism, etc., various sizes and directions will occur. Therefore, it is difficult to ensure stable rotor load reduction and it is difficult to take into account both rotor load reduction and stator coil voltage stabilization under various interference factors by setting only one excitation coil. However, this scheme chooses to set at least two excitation coils, so that this scheme has more control dimensions (including the current parameters of the two excitation coils, and the current difference between the two excitation coils), which can take into account both rotor load reduction and stator coil voltage stabilization.

[0016] The magnetic field generated by the excitation coil can also excite the rotor, thereby increasing the torque received by the rotor in the rotating magnetic field, allowing the rotor to be driven to a higher speed, thereby improving the energy storage efficiency and storage capacity of the rotor.

[0017] As can be seen from the above, this solution drives the rotor to rotate through a rotating magnetic field. Therefore, the rotor only needs to be able to conduct magnetism, and there is no need to embed permanent magnets on the rotor like the existing flywheel permanent magnet motor. It has the advantages of simple structure and low manufacturing cost. And because it does not contain permanent magnets, it can also avoid the problems of rotor heating, magnetic field temperature sensitivity, magnetic field attenuation, magnetic field adjustment difficulty, high cost and environmental pollution caused by permanent magnets, and has better temperature resistance and environmental adaptability. At the same time, this solution can also use the differential adjustment of the excitation coils at both ends of the rotor to offset part or even all of the rotor's own weight, thereby greatly reducing the burden on the bearings, making it possible to directly use mechanical bearings to rotate and position the rotor, and is beneficial to increasing the service life of the bearings.

[0018] Preferably, at least one end of the rotor is provided with a sensor assembly, the sensor assembly being a force sensor and / or a displacement sensor.

[0019] This solution enables the staff to accurately judge the load-reducing effect of the excitation coil on the rotor through the readings of the sensor assembly, so as to implement corresponding countermeasures according to the specific situation, such as increasing or decreasing the current in the excitation coil or changing the current direction in the excitation coil.

[0020] Preferably, an excitation current controller is also included. The excitation coil is communicatively connected to the sensor assembly, and the excitation current controller is used to control the current in the excitation coil.

[0021] This solution forms a closed-loop system through an excitation current controller, a sensor assembly and an excitation coil, so that the current in the excitation coil can be adjusted in real time according to the reading of the sensor assembly, so as to help the excitation coil cope with magnetic circuit interference and other external disturbances from the stator coil, thereby providing a stable and reliable load reduction effect for the stator.

[0022] Preferably, a plurality of tooth slots are arranged on a side of the rotor facing the rotor, the length of the tooth slots is arranged along the axial direction of the rotor, and the tooth slots are distributed at intervals along the circumference of the rotor.

[0023] This solution can make the rotor have different magnetic resistances at different positions along its circumference by arranging teeth slots at intervals along the circumference of the rotor; when the rotor is located in the rotating magnetic field formed by the stator, due to the principle of minimum magnetic resistance, the rotor will be pulled to the minimum magnetic resistance position by the electromagnetic torque formed by the magnetic pull, so that it can rotate with the rotating magnetic field; compared with a rotating body rotor without teeth slots and relying only on induced current and electromagnetic force to generate torque, this solution can generate greater torque, thereby driving the rotor to a higher speed, thereby improving the energy storage efficiency and storage capacity of the rotor.

[0024] Preferably, the tooth grooves penetrate the rotor along the axial direction of the rotor.

[0025] This solution can further increase the difference in magnetic resistance between the rotor where the tooth slots are provided and the rotor where the tooth slots are not provided, thereby increasing the electromagnetic torque received by the rotor.

[0026] Preferably, a plurality of limiting grooves are arranged on a side of the stator facing the rotor, the length of the limiting grooves is arranged along the axial direction of the stator, the limiting grooves are spaced apart along the circumferential direction of the stator, and the stator coils are wound around the limiting grooves.

[0027] In this solution, the limiting groove is processed on the stator, which can facilitate the winding of the stator coil on the stator and form a reliable limit for the stator coil; on the other hand, it can also increase the surface area of ​​the stator, which is beneficial to improving the heat dissipation efficiency of the stator.

[0028] Preferably, the width of the limiting groove at one end close to the rotor is smaller than the width of the limiting groove at one end away from the rotor.

[0029] This solution can further reduce the possibility of the stator coil detaching from the stator in the radial direction of the stator through the shape of the limiting groove.

[0030] Preferably, the stator includes at least two laminated sheets stacked along an axial direction thereof.

[0031] The stator of the present solution is made of stacked laminated sheets, which can limit the path of eddy currents in the stator, thereby reducing eddy current losses, hysteresis losses and heat generation of the stator, thereby improving the energy conversion efficiency of the present solution; at the same time, it also enables the stator to dissipate heat through the area between two adjacent laminated sheets, which can improve the heat dissipation efficiency of the stator.

[0032] Preferably, the rotor is a one-piece solid component.

[0033] This solution recommends that the rotor directly adopt an integrated solid structure, which can greatly simplify the structural complexity of the rotor, thereby reducing the manufacturing cost of the rotor, improving the structural strength of the rotor, and making the rotor have a higher energy density.

[0034] In a second aspect, the present invention provides a method for using a flywheel energy storage motor, which is applied to a flywheel energy storage motor of the present invention, comprising the following steps:

[0035] By passing alternating current into the stator coil, a rotating magnetic field is generated around the rotor axis, thereby driving the rotor to rotate around its axis;

[0036] Direct current is passed through the excitation coils at both ends of the rotor, and the current in the excitation coils at both ends is adjusted so that the rotor is subjected to a resultant force in the opposite direction to the gravity.

[0037] This solution generates a rotating magnetic field by passing alternating current into the stator coil, which can drive the rotor that does not contain permanent magnets to rotate, thereby helping to simplify the structure of the rotor and get rid of the problems of rotor heating, magnetic field temperature sensitivity, magnetic field attenuation, difficulty in magnetic field regulation, high cost and environmental pollution caused by permanent magnets; at the same time, by adjusting the current in the excitation coils at both ends, the rotor can be subjected to a combined force opposite to the direction of gravity, which can offset part or even all of the rotor's own weight, thereby greatly reducing the burden on the bearings, making it possible to directly use mechanical bearings to rotate and position the rotor, and helping to increase the service life of the bearings.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The present invention provides a flywheel energy storage motor, which drives the rotor to rotate through the rotating magnetic field generated by the stator coil to complete the conversion of electrical energy and mechanical energy; the magnetic field generated by the excitation coil stabilizes the voltage in the stator coil and excites the rotor; the entire flywheel energy storage motor does not need to use permanent magnets, so it has a simpler rotor structure and magnetic circuit, thereby being able to obtain higher rotor strength, lower manufacturing and operation and maintenance costs, and can avoid the problems of rotor heating, magnetic field temperature sensitivity, magnetic field attenuation, magnetic field adjustment difficulty, high cost and environmental pollution caused by permanent magnets, and has better temperature resistance and environmental adaptability.

[0040] The present invention can also offset part or even all of the rotor's own weight through the magnetic field generated by the excitation coil, thereby greatly reducing the burden on the bearing, making it possible to directly use mechanical bearings to rotationally position the rotor, and facilitating increasing the service life of the bearing.

[0041] 2. The present invention provides a method for using a flywheel energy storage motor, which can generate a rotating magnetic field through a stator coil to drive a rotor that does not contain a permanent magnet to rotate, and offset part or even all of the rotor's own weight through an axial magnetic field generated by two excitation coils, which is beneficial to simplifying the structure of the flywheel energy storage motor and improving the service life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of a 1 / 4 cross-sectional isometric structure of a flywheel energy storage motor of the present invention;

[0043] Figure 2 It is a schematic diagram of a top view and cross-section structure of a flywheel energy storage motor of the present invention;

[0044] Figure 3 It is a three-dimensional structural schematic diagram of a rotor of a flywheel energy storage motor of the present invention;

[0045] Figure 4 It is a schematic diagram of a magnetic flux circuit generated by a stator coil of a flywheel energy storage motor of the present invention;

[0046] Figure 5 yes Figure 4 A schematic diagram of the local enlarged structure at point A in the middle;

[0047] Figure 6 It is a schematic diagram of the magnetic flux circuit generated by the excitation coil of a flywheel energy storage motor of the present invention; Icon:

[0048] 1-housing; 11-cylinder; 12-end cover; 13-bearing seat; 14-rolling bearing;

[0049] 2- rotor; 21- shaft; 22- tooth groove;

[0050] 3-stator; 31-stator coil;

[0051] 4- Excitation coil;

[0052] 5-Sensor assembly. DETAILED DESCRIPTION

[0053] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0054] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, rather than indicating or implying that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0055] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0056] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0057] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0058] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0059] Example 1

[0060] like Figures 1 to 6As shown, a flywheel energy storage motor comprises a housing 1, a rotor 2, a stator 3 and an excitation coil 4; the rotor 2 is rotatably connected to the inside of the housing 1 through a rolling bearing 14, and the magnetic resistance of the rotor 2 is unevenly distributed along its circumferential direction; the stator 3 is arranged around the outer side of the rotor 2 along the circumferential direction of the rotor 2 (that is, the side of the rotor 2 facing the inner side wall of the housing 1 along its radial direction), and the stator 3 is connected to the housing 1, so as to be fixed relative to the housing 1; the stator 3 is connected to a stator coil 31 on the side facing the rotor 2, and the stator coil 31 is used to generate a rotating magnetic field that can rotate around the axis of the rotor 2; there is a radial gap between the stator 3 and the rotor 2, and between the stator coil 31 and the rotor 2; at least one excitation coil 4 is respectively arranged at both ends of the rotor 2 along its axial direction, and the excitation coil 4 is connected to the housing 1, so as to be fixed relative to the housing 1; the axis of the excitation coil 4 is parallel to the axis of the rotor 2, and there is an axial gap between the excitation coil 4 and the stator 3; and the rotor 2, the stator 3 and the excitation coil 4 are all coaxially arranged.

[0061] In an optional embodiment, the shell 1 includes a hollow cylinder 11, and the two ends of the cylinder 11 along the axial direction are respectively connected to end covers 12, the cylinder 11 and the end covers 12 at both ends can jointly enclose a hollow chamber for mounting the stator 3, the rotor 2 and the excitation coil 4, and there is an axial gap between the end cover 12 and the rotor 2; a bearing seat 13 is arranged at the center of the end cover 12, and correspondingly, the rotor 2 is provided with a protruding rotating shaft 21 at both ends along the axial direction, and each rotating shaft 21 is connected to at least one rolling bearing 14; the inner ring of the rolling bearing 14 is connected to the rotating shaft 21, the outer ring of the rolling bearing 14 is connected to the bearing seat 13, and the rotor 2 and its rotating shaft 21, the rolling bearings 14 at both ends of the rotor 2 and the bearing seats 13 at both ends of the rotor 2 are coaxially arranged, so that the rotor 2 can rotate freely relative to the shell 1.

[0062] In an optional embodiment, a sealing structure, such as a sealing ring or a sealant, can be provided between the end cover 12 and the cylinder 11, which is conducive to enclosing the end cover 12 and the cylinder 11 into a vacuum chamber, thereby greatly reducing the wind resistance loss of the rotor 2 during operation and improving the operating efficiency of the flywheel energy storage motor.

[0063] In an optional embodiment, the end covers 12 at both ends of the rotor 2 are respectively equal in size to the axial gap between the rotor 2, thereby facilitating the formation of a symmetrical magnetic field at both ends of the rotor 2 along its axial direction.

[0064] In an optional embodiment, the excitation coils 4 at both ends of the rotor 2 are respectively connected to the corresponding end covers 12 ; and a side of the excitation coil 4 facing the rotor 2 is flush with a side of the corresponding end cover 12 facing the rotor 2 .

[0065] In an optional embodiment, the cylinder 11 and the end cover 12 are both made of ferromagnetic materials, such as iron, nickel or cobalt, to perform magnetic conductivity; and the bearing seat 13 can be made of non-ferromagnetic materials, such as ceramic or austenitic stainless steel, to reduce magnetic leakage at the bearing seat 13.

[0066] In an optional embodiment, the connection method between the stator 3 and the housing 1 includes, but is not limited to: fastening connection through a threaded connector, connection through a key positioning method, and connection through an interference fit method.

[0067] In an optional embodiment, the stator coil 31 can generate a rotating magnetic field in a manner that refers to the existing RMF technology (Rotating Magnetic Field), for example: the stator coil 31 includes n groups of coil units spaced apart along the circumference of the rotor 2, where n matches the number of phases of the power supply; the winding axis of the coil unit is arranged along the radial direction of the stator 3, so that the coil unit can form a magnetic field along the radial direction of the stator 3 after being energized; alternating current with different phases is introduced into each coil unit, and the magnetic fields generated by each coil unit will combine with each other to form a combined magnetic field, and as the alternating current changes with time, the combined magnetic field can rotate around the axis of the rotor 2, thereby driving the rotor 2 to rotate around its axis. The specific connection method between the stator coil 31 and the stator 3 can refer to the existing armature winding, including but not limited to lap winding, wave winding and frog winding.

[0068] In an optional embodiment, a plurality of limit grooves are provided on one side of the stator 3 facing the rotor 2. The length of the limit grooves is arranged along the axial direction of the stator 3 and can directly pass through the stator 3 along the axial direction of the stator 3. The limit grooves are distributed at intervals along the circumference of the stator 3, and the stator coil 31 is wound around the limit grooves.

[0069] In an optional embodiment, the width of the limiting groove at one end close to the rotor 2 is smaller than the width of the limiting groove at one end away from the rotor 2. The width of the limiting groove may be varied in a manner including, but not limited to, gradually decreasing from one end away from the rotor 2 to one end close to the rotor 2, or decreasing in a stepwise manner from one end away from the rotor 2 to one end close to the rotor 2; for example Figure 5 As shown, the width of the limiting groove away from the rotor 2 is W1, and the width of the limiting groove close to the rotor 2 is W2, and W1 is greater than W2, so that the stator coil 31 can be stuck in the limiting groove to prevent the stator coil 31 from escaping.

[0070] In an optional embodiment, the stator 3 includes at least two laminated sheets stacked along its axial direction. The specific lamination process of the laminated sheets can adopt existing technologies, such as bonding two adjacent laminated sheets with an insulating adhesive, or punching out a stacking anchor point with a convex side and a concave side on the laminated sheet through a stamping process, and then connecting the two adjacent laminated sheets to each other through the stacking anchor point.

[0071] In an optional embodiment, the laminated sheets are made of silicon steel, which has high magnetic permeability and low eddy current loss, and can significantly reduce the iron loss of the stator 3 .

[0072] In an optional embodiment, the central plane of the stator 3 along its axis coincides with the central plane of the rotor 2 along its axis, so that the magnetic field formed by the stator coil 31 can be symmetrically distributed on both sides of the central plane of the rotor 2 along its axis, thereby forming a uniform and symmetrical magnetic field. Figure 6 As shown, both end surfaces of the stator 3 along its axial direction are flush with the two end surfaces of the rotor 2 along its axial direction.

[0073] In an optional embodiment, the number of lead wires of the stator coil 31 matches the number of phases of the AC current passed therein; the positions of the lead wires include but are not limited to being led out from the side wall of the cylinder 11 and from the end cover 12 .

[0074] In an optional embodiment, a sensor assembly 5 is provided at at least one end of the rotor 2, and the sensor assembly 5 includes a force sensor and / or a displacement sensor for detecting the load generated by the rotor 2 on the rolling bearing 14; the specific form of the force sensor includes but is not limited to a tension sensor or a pressure sensor; the specific setting position of the force sensor matches its type; for example, if the force sensor is a pressure sensor, the force sensor should be arranged at the lower end of the rotor 2; if the force sensor is a tension sensor, the force sensor should be arranged at the upper end of the rotor 2; if a displacement sensor is used, it can be arranged at the upper end or the lower end of the rotor 2.

[0075] In an optional embodiment, an excitation current controller is further included, and the excitation coil 4 is communicatively connected with the sensor assembly 5. The excitation current controller is used to control the current in the excitation coil 4, such as the magnitude of the current and the direction of the current. The excitation current controller can adopt existing technologies, such as a resistor assembly, a potentiometer assembly, a transformer assembly, and a relay assembly.

[0076] In an optional embodiment, the magnetic resistance of the rotor 2 is unevenly distributed along its circumference, which means that the magnetic resistance of the rotor 2 is not constant along its circumference, so that it has a minimum magnetic resistance position relative to the rotating magnetic field; specific implementation methods include but are not limited to: using materials with different magnetic resistances at different positions along the circumference of the rotor 2, or making different positions along the circumference of the rotor 2 into different shapes.

[0077] In an optional embodiment, a plurality of tooth slots 22 are provided on one side of the rotor 2 facing the rotor 2, the length of the tooth slots 22 is provided along the axial direction of the rotor 2, and the tooth slots 22 are spaced apart along the circumference of the rotor 2; the portion between two adjacent tooth slots 22 is a tooth, which can be attracted by the rotating magnetic field as a salient pole of the rotor and drive the rotor 2 to rotate with the rotating magnetic field. The cross-sectional shape of the tooth slots 22 can be any shape, including but not limited to a trapezoid, a rectangle or an arc.

[0078] In an optional implementation manner, the number of tooth slots 22 on the rotor 2 is m, and the number of limit slots on the stator 3 is 6*m, where m=3, 4, 5, 6, etc. For example Figure 4 As shown, six tooth slots 22 are provided on the rotor 2, and correspondingly, the number of teeth on the rotor 2 is also 6; and the number of limiting slots on the stator 3 is 36, so each tooth slot 22 and tooth of the rotor 2 can correspond to the three limiting slots on the stator 3 respectively; after testing, this configuration is conducive to making the rotor 2 rotate more smoothly and obtaining a larger electromagnetic torque.

[0079] In an optional embodiment, the tooth groove 22 passes through the rotor 2 along the axial direction of the rotor 2 .

[0080] In an optional embodiment, the rotor 2 is an integrated solid component.

[0081] Example 2

[0082] A method for using a flywheel energy storage motor, applied to a flywheel energy storage motor in Example 1, comprises the following steps:

[0083] Place the flywheel energy storage motor vertically on the ground, so that the axis of the rotor 2 is parallel to the direction of gravity; pass alternating current into the stator coil 31 to form a Figure 4 The rotating magnetic field shown in FIG. 1 ; the magnetic flux circuit of the rotating magnetic field is: stator 3 -> radial air gap -> rotor 2 -> radial air gap -> stator 3; from Figure 4 It can be seen that due to the existence of the tooth slots 22 of the rotor 2, the rotor 2 has different magnetic resistances at different positions along its circumference; and since the magnetic flux is always closed along the path with the smallest magnetic resistance, the rotating magnetic field can generate an uninterrupted tangential electromagnetic torque on the rotor 2, thereby driving the rotor 2 to rotate.

[0084] Direct current is supplied to the excitation coils 4 at both ends of the rotor 2, so that the excitation coils 4 at both ends of the rotor 2 can be formed as follows: Figure 6 The magnetic field shown has a magnetic flux circuit as follows: end cover 12->axial air gap->rotor 2->radial air gap->stator 3->cylinder 11->end cover 12; due to the effect of the air gap magnetic field, the end covers 12 at both ends of the rotor 2 can pull the rotor 2 from both ends of the rotor 2 respectively, and by adjusting the current in the excitation coils 4 at both ends, such as the current magnitude and current direction, the direction and magnitude of the resultant force acting on the rotor 2 can be adjusted, thereby causing the rotor 2 to be subjected to a resultant force opposite to the direction of gravity, so as to offset part or even all of the deadweight of the rotor 2.

[0085] In the above embodiment, since the magnitude and direction of the resultant force acting on the rotor 2 along its axial direction will be affected by various factors such as the size of the air gap between the rotor 2 and the excitation coil 4, assembly errors, and the residual magnetism of the housing 1, the current magnitude in the excitation coils 4 at both ends of the rotor 2 is not fixed, but needs to be dynamically adjusted in real time according to the actual force conditions of the rotor 2. It is possible that the current value in the upper excitation coil 4 is greater than the current value in the lower excitation coil 4, or it is possible that the current value in the upper excitation coil 4 is less than the current value in the lower excitation coil 4.

[0086] In an optional implementation, the following step is further included: increasing the difference in current in the excitation coils 4 at both ends of the rotor 2 so as to increase the magnitude of the resultant force acting on the rotor 2 along its axial direction.

[0087] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flywheel energy storage motor, characterized in that: include: Housing (1); A rotor (2), the rotor (2) being rotatably connected to the interior of the housing (1); the magnetic resistance of the rotor (2) being unevenly distributed along its circumference; A stator (3), the stator (3) being arranged around the outer side of the rotor (2) along the circumferential direction of the rotor (2), the stator (3) being connected to the housing (1); a stator coil (31) being connected to a surface of the stator (3) facing the rotor (2), the stator coil (31) being used to generate a rotating magnetic field capable of rotating around an axis of the rotor (2); a gap is provided between the stator (3) and the rotor (2), and between the stator coil (31) and the rotor (2); An excitation coil (4), wherein at least one excitation coil (4) is respectively arranged at both ends of the rotor (2) along the axial direction thereof, the excitation coil (4) is connected to the housing (1), the axis of the excitation coil (4) is parallel to the axis of the rotor (2), and there is a gap between the excitation coil (4) and the stator (3).

2. A flywheel energy storage motor according to claim 1, characterized in that: At least one end of the rotor (2) is provided with a sensor assembly (5), and the sensor assembly (5) comprises a force sensor and / or a displacement sensor.

3. A flywheel energy storage motor according to claim 2, characterized in that: It also includes an excitation current controller, the excitation coil (4) is communicatively connected with the sensor assembly (5), and the excitation current controller is used to control the current in the excitation coil (4).

4. A flywheel energy storage motor according to any one of claims 1 to 3, characterized in that: A plurality of tooth slots (22) are arranged on a side of the rotor (2) facing the rotor (2), the length of the tooth slots (22) is arranged along the axial direction of the rotor (2), and the tooth slots (22) are distributed at intervals along the circumference of the rotor (2).

5. A flywheel energy storage motor according to claim 4, characterized in that: The tooth groove (22) passes through the rotor (2) along the axial direction of the rotor (2).

6. A flywheel energy storage motor according to any one of claims 1 to 3, characterized in that: A plurality of limiting grooves are arranged on a side of the stator (3) facing the rotor (2), the length of the limiting grooves being arranged along the axial direction of the stator (3), the limiting grooves being distributed at intervals along the circumference of the stator (3), and the stator coils (31) being wound around the limiting grooves.

7. A flywheel energy storage motor according to claim 6, characterized in that: The width of the limiting groove at one end close to the rotor (2) is smaller than the width of the limiting groove at one end away from the rotor (2).

8. A flywheel energy storage motor according to any one of claims 1 to 3, characterized in that: The stator (3) comprises at least two laminated sheets which are stacked along the axial direction thereof.

9. A flywheel energy storage motor according to any one of claims 1 to 3, characterized in that: The rotor (2) is an integrated solid component.

10. A method for using a flywheel energy storage motor, characterized in that: A flywheel energy storage motor as claimed in any one of claims 1 to 9, comprising the following steps: An alternating current is passed through the stator coil (31) to generate a rotating magnetic field rotating around the axis of the rotor (2), thereby driving the rotor (2) to rotate around its axis; Direct current is supplied to the excitation coils (4) at both ends of the rotor (2), and the currents in the excitation coils (4) at both ends are adjusted so that the rotor (2) is subjected to a resultant force in the opposite direction to the gravity.

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