Variable flux flywheel energy storage device and variable flux flywheel energy storage device control method

Abstract

The invention relates to a variable magnetic flux flywheel energy storage device and a variable magnetic flux flywheel energy storage device control method. The problem that in the prior art, standby loss exists in an inductor motor, and the energy conversion efficiency is remarkably reduced can be solved. The variable magnetic flux flywheel energy storage device comprises a rotor, a stator, a magnetic field adjusting coil and a permanent magnet ring, the stator, the magnetic field adjusting coil and the permanent magnet ring are arranged around a rotating shaft of the rotor in the circumferential direction of the rotor, the permanent magnet ring comprises permanent magnet parts and magnetic leakage parts which are alternately arranged in the circumferential direction, and an air gap is formed between the stator and the rotor. The magnetic field adjusting coil can generate excitation magnetic flux in a power-on state to preempt the space of the magnetic leakage part, the magnetic flux of the permanent magnet ring is completely introduced into the air gap to enhance the magnetic density of the air gap, and the magnetic flux of the permanent magnet part can flow through the magnetic leakage part from one end of the permanent magnet part and then return to the other end of the permanent magnet part in a power-off state of the magnetic field adjusting coil.

Description

Technical Field

[0001] The present application relates to the technical field of motor energy storage, and in particular to a variable magnetic flux flywheel energy storage device and a control method for the variable magnetic flux flywheel energy storage device. Background Art

[0002] As a highly efficient energy storage technology, the flywheel energy storage system has the advantages of high energy density, rapid response and long life. It has received extensive attention and application in the fields of grid frequency regulation, power system energy storage, and renewable energy grid connection, especially in the field of induction motors.

[0003] In the prior art, induction motors mainly rely on high-speed motors to maintain high-speed rotation of the rotor so as to quickly provide energy when needed. However, when the induction motor is in standby mode, that is, when the induction motor is in a non-output state, the stator core of the motor will still be affected by the air gap magnetic field, thereby generating iron loss. This standby loss will significantly reduce the energy conversion efficiency of the induction motor. Summary of the invention

[0004] Based on this, it is necessary to provide a variable magnetic flux flywheel energy storage device and a control method for a variable magnetic flux flywheel energy storage device to address the problem that the standby loss of the induction motor in the prior art significantly reduces the energy conversion efficiency.

[0005] According to one aspect of the present application, the present application provides a variable magnetic flux flywheel energy storage device, which includes a rotor, a stator, a magnetic adjustment coil and a permanent magnetic ring, wherein the stator, the magnetic adjustment coil and the permanent magnetic ring are all arranged around the rotating shaft of the rotor along the circumference of the rotor, the permanent magnetic ring includes a permanent magnetic part and a leakage magnetic part alternately arranged along the circumference, and an air gap is provided between the stator and the rotor. The magnetic adjustment coil can generate an excitation magnetic flux in a power-on state to occupy the space of the leakage magnetic part, and make the magnetic flux of the permanent magnetic ring pass completely into the air gap to enhance the magnetic density of the air gap, and the magnetic flux of the permanent magnetic part can flow from one end of the permanent magnetic part through the leakage magnetic part and return to the other end of the permanent magnetic part when the magnetic adjustment coil is powered off.

[0006] The variable magnetic flux flywheel energy storage device is configured by alternating the permanent magnetic part and the leakage magnetic part along the circumferential direction of the permanent magnetic ring, so that the magnetic flux regulating coil can generate excitation magnetic flux in the power-on state to occupy the space of the leakage magnetic part, and the magnetic flux of the permanent magnetic part is completely passed into the air gap to enhance the magnetic density of the air gap, thereby realizing the excitation effect of the variable magnetic flux flywheel energy storage device during charging and discharging. In addition, when the magnetic flux regulating coil is powered off, the magnetic flux of the permanent magnetic part will flow through the leakage magnetic part and return to the permanent magnetic part, so that in the standby state, the magnetic flux of the air gap can be reduced by powering off the magnetic flux regulating coil, thereby effectively reducing the iron loss in the standby state, and improving the energy conversion rate of the variable magnetic flux flywheel energy storage device.

[0007] In one embodiment, the stator includes a first stator winding and a second stator winding, the first stator winding and the second stator winding are arranged at intervals along the extension direction of the rotating shaft, and the permanent magnet ring and the magnetic tuning coil are clamped between the first stator winding and the second stator winding.

[0008] In one embodiment, the permanent magnet portion and the leakage magnetic portion are integrally formed.

[0009] In one embodiment, the permanent magnet part is made of low coercive force permanent magnet material.

[0010] In one embodiment, the permanent magnet part is made of aluminum nickel cobalt material.

[0011] In one of the embodiments, the magnetic leakage portion is made of low magnetic resistance material.

[0012] In one of the embodiments, the magnetic leakage part is made of structural steel material.

[0013] In one embodiment, the variable magnetic flux flywheel energy storage device includes a casing having a receiving cavity, the stator is arranged in the receiving cavity and is fixed to the casing, at least part of the structure of the rotor is passed through the receiving cavity and is suspended relative to the stator under the action of the permanent magnet ring.

[0014] In one embodiment, the variable magnetic flux flywheel energy storage device includes a flywheel mechanism connected to the rotor.

[0015] According to another aspect of the present application, the present application also provides a variable magnetic flux flywheel energy storage device control method, which is applied to the above-mentioned variable magnetic flux flywheel energy storage device, and the flywheel energy storage device control method includes:

[0016] When the variable magnetic flux flywheel energy storage device is charged / discharged, the magnetic adjustment coil is energized so that the magnetic adjustment coil generates a magnetic adjustment magnetic flux, most of which flows into the magnetic leakage part to occupy the space of the magnetic leakage part, so that the magnetic flux of the permanent magnet part is completely passed into the air gap between the rotor and the stator;

[0017] When the variable magnetic flux flywheel energy storage device is on standby, a demagnetization pulse current is first passed through the magnetic adjustment coil to reduce the residual magnetism of the permanent magnet part, and then the current of the magnetic adjustment coil is reduced to 0, so that the magnetic flux of the permanent magnet part flows from one end through the leakage magnetic part and then returns to the other end of the permanent magnet part.

[0018] The control method of the variable flux flywheel energy storage device is to energize the magnetic adjustment coil when the variable flux flywheel energy storage device is charged / discharged, so that the magnetic adjustment coil generates magnetic adjustment magnetic flux, and most of the magnetic adjustment magnetic flux is passed into the leakage magnetic part to occupy the space of the leakage magnetic part, and then the magnetic flux of the permanent magnetic part is completely passed into the air gap to enhance the magnetic density of the air gap, so as to achieve the excitation effect of the variable flux flywheel energy storage device during charging and discharging. In addition, when the variable flux flywheel energy storage device is on standby, a demagnetization pulse current is first passed into the magnetic adjustment coil, so as to help the magnetic adjustment coil restore the original magnetic flux, and then the current of the magnetic adjustment coil is reduced to 0, so that the magnetic flux of the permanent magnetic part flows from one end through the leakage magnetic part and then returns to the other end of the permanent magnetic part, and then the magnetic density of the air gap is reduced in the standby state, which helps to reduce the iron loss during standby and improve the energy conversion rate of the variable flux flywheel energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of a variable magnetic flux flywheel energy storage device in one embodiment of the present application.

[0020] FIG. 2 is a schematic structural diagram of the permanent magnet ring of the variable magnetic flux flywheel energy storage device shown in FIG. 1 .

[0021] FIG. 3 is a schematic diagram of the magnetic flux path of the variable magnetic flux flywheel energy storage device shown in FIG. 1 during charging / discharging.

[0022] FIG. 4 is a schematic diagram of the magnetic flux path of the variable magnetic flux flywheel energy storage device shown in FIG. 1 when in standby mode.

[0023] FIG5 is a flow chart of a method for controlling a variable magnetic flux flywheel energy storage device in an embodiment of the present application.

[0024] Description of Figure Numbers

[0025] 10. variable magnetic flux flywheel energy storage device; 11. rotor; 12. stator; 121. first stator winding; 122. second stator winding; 13. magnetic adjustment coil; 14. permanent magnetic ring; 141. permanent magnetic part; 142. leakage magnetic part. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0027] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0028] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0030] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0032] Considering that the stator core of the existing induction motor is still affected by the air gap magnetic field in the standby condition, that is, when the induction motor is in a non-output state, the stator core of the motor will still be affected by the air gap magnetic field, thereby generating iron loss. This standby loss will significantly reduce the energy conversion efficiency of the induction motor. The present application provides a variable magnetic flux flywheel energy storage device and a control method for a variable magnetic flux flywheel energy storage device, which can effectively reduce the magnetic flux in the air gap when the variable magnetic flux flywheel energy storage device is in standby mode, thereby helping to reduce the iron loss during standby, improve the energy conversion rate of the variable magnetic flux flywheel energy storage device, and facilitate application and promotion.

[0033] Specifically, please refer to Figures 1 and 2. An embodiment of the present application provides a variable magnetic flux flywheel energy storage device 10, which may include a rotor 11, a stator 12, a magnetic adjustment coil 13 and a permanent magnetic ring 14. The stator 12, the magnetic adjustment coil 13 and the permanent magnetic ring 14 are all arranged around the rotating shaft of the rotor 11 along the circumference of the rotor 11. As shown in Figure 2, the permanent magnetic ring 14 includes a permanent magnetic part 141 and a leakage magnetic part 142 alternately arranged along the circumference, and there is an air gap between the stator 12 and the rotor 11. As shown in Figure 3, the magnetic adjustment coil 13 can generate an excitation magnetic flux in the power-on state to occupy the space of the leakage magnetic part 142, and make the magnetic flux of the permanent magnetic ring 14 pass into the air gap to enhance the magnetic density of the air gap. As shown in Figure 4, the magnetic flux of the permanent magnetic part 141 can flow from one end of the permanent magnetic part 141 through the leakage magnetic part 142 and return to the other end of the permanent magnetic part 141 when the magnetic adjustment coil 13 is powered off.

[0034] The variable magnetic flux flywheel energy storage device 10 is configured by alternating the permanent magnetic part 141 and the leakage magnetic part 142 along the circumferential direction through the permanent magnetic ring 14, so that the magnetic adjustment coil 13 can generate an excitation magnetic flux in the power-on state to occupy the space of the leakage magnetic part 142, and the magnetic flux of the permanent magnetic ring 14 is completely passed into the air gap to enhance the magnetic density of the air gap, thereby realizing the excitation effect of the variable magnetic flux flywheel energy storage device 10 during charging and discharging. In addition, when the magnetic adjustment coil 13 is powered off, the magnetic flux of the permanent magnetic part 141 will flow through the leakage magnetic part 142 and return to the permanent magnetic part 141, so that in the standby state, the magnetic adjustment coil 13 can be powered off to reduce the magnetic density of the air gap, thereby effectively reducing the iron loss during standby, and improving the energy conversion rate of the variable magnetic flux flywheel energy storage device 10.

[0035] It should be noted that the aforementioned air gap in the variable flux flywheel energy storage device 10 of the present application refers to the gap between the stator 12 and the rotor 11. The aforementioned air gap enables the rotor 11 to suspend in the magnetic field generated by the permanent magnet ring 14 without being affected by physical contact, thereby realizing contactless rotation of the rotor 11, which helps to reduce friction and wear and improve energy conversion efficiency. Understandably, in an induction motor, the aforementioned air gap may refer to the gap between the stator and the rotor of the motor, which ensures the normal operation of the motor and prevents mechanical damage and performance degradation due to direct contact between the stator and the rotor.

[0036] It is worth noting that when the variable magnetic flux flywheel energy storage device 10 is charged and discharged, the magnetic flux adjustment coil 13 and the permanent magnetic ring 14 simultaneously provide magnetic flux to the air gap. As shown in FIG4 , when the variable magnetic flux flywheel energy storage device 10 is charged and discharged, the magnetic flux adjustment coil 13 can be energized and generate a magnetic flux in the same direction as the permanent magnetic ring 14, so as to achieve the excitation effect. It can be understood that when the magnetic flux adjustment coil 13 stops being energized, the magnetic flux adjustment drops to 0.

[0037] Optionally, the leakage magnetic part 142 is made of low magnetic resistance material, so that when the magnetic adjustment coil 13 is powered on, the excitation magnetic flux generated by it can preferentially occupy the space of the leakage magnetic part 142, thereby preventing the magnetic flux generated by the permanent magnetic part 141 from flowing through the leakage magnetic part 142, so that the magnetic flux of the permanent magnetic part 141 all flows into the air gap, thereby realizing the excitation effect of the magnetic adjustment coil 13, and allowing the excitation coil 13 and the permanent magnetic ring 14 to simultaneously provide magnetic flux to the air gap to enhance the magnetic density of the air gap, thereby ensuring the working reliability of the variable magnetic flux flywheel energy storage device 10 during charging and discharging.

[0038] Specifically, low magnetic resistance material usually refers to a material with a high magnetic permeability characteristic. High magnetic permeability means small magnetic resistance, which can more effectively conduct the magnetic field, so that the excitation flux of the magnetic tuning coil 13 and the magnetic flux of the permanent magnet part 141 when the magnetic tuning coil 13 is powered off can flow through the leakage magnetic part 142 preferentially.

[0039] In addition, since the leakage magnetic part 142 is made of low magnetic resistance material, when the magnetic adjustment coil 13 is powered off, the magnetic flux of the permanent magnetic part 141 will flow out from one end and preferentially flow into the leakage magnetic part 142, and then flow back to the other end of the permanent magnetic part 141 to form a closed loop, which helps to reduce the magnetic flux of the permanent magnetic part 141 flowing through the air gap, thereby helping to reduce the magnetic density of the air gap of the variable magnetic flux flywheel energy storage device 10 when it is on standby, thereby reducing the iron loss during standby and improving the energy conversion rate of the variable magnetic flux flywheel energy storage device 10.

[0040] Optionally, the permanent magnet portion 141 and the leakage magnetic portion 142 can be implemented with the same length along the circumferential direction but are not limited to being implemented, so that the symmetry of the structure can be improved, and then the uniformity of the permanent magnet portion 141 flowing through the leakage magnetic portion 142 can be improved, which helps to reduce the magnetic flux of the permanent magnet portion 141 flowing through the air gap, thereby helping to reduce the magnetic density of the air gap of the variable magnetic flux flywheel energy storage device 10 when it is on standby, and then reduce the iron loss when on standby, and improve the energy conversion rate of the variable magnetic flux flywheel energy storage device 10.

[0041] Optionally, the permanent magnet portion 141 and the leakage magnetic portion 142 can be integrally formed, which can improve the structural integrity and structural strength, and also help to improve the uniformity and magnetic flux density of the permanent magnet portion 141 flowing through the leakage magnetic portion 142, thereby improving the energy conversion rate of the variable magnetic flux flywheel energy storage device 10.

[0042] Optionally, the magnetic leakage portion 142 may be made of, but not limited to, a soft magnetic alloy material or a Sendust powder core.

[0043] Optionally, the magnetic leakage part 142 is made of structural steel material. It should be noted that structural steel material is a type of steel used to build structures and mechanical parts, which has sufficient strength, toughness and weldability. In this embodiment of the present application, the use of structural steel material can better improve the structural strength while taking into account the qualified low magnetic resistance, thereby increasing the structural stability of the variable magnetic flux flywheel energy storage device 10.

[0044] Optionally, the magnetic leakage portion 142 may be made of, but is not limited to, low magnetic steel or high manganese low magnetic steel.

[0045] Optionally, referring to FIG1 , the stator 12 may include a first stator winding 121 and a second stator winding 122, the first stator winding 121 and the second stator winding 122 are arranged at intervals along the extension direction of the rotating shaft, and the permanent magnet ring 14 and the magnetic adjustment coil 13 are sandwiched between the first stator winding 121 and the second stator winding 122. It can be understood that, in combination with FIG1 , the permanent magnet ring 14 and the magnetic adjustment coil 13 are stacked along the extension direction of the rotating shaft, and the stacking order can be adjusted according to actual design requirements.

[0046] Specifically, this embodiment adopts two stator windings, namely a first stator winding 121 and a second stator winding 122, which are arranged axially at intervals. This helps to improve the power density and torque density of the variable magnetic flux flywheel energy storage device 10. Secondly, it can also optimize the structural layout, so that the permanent magnet ring 14 and the magnetic tuning coil 13 can be clamped between the first stator winding 121 and the second stator winding 122, thereby optimizing the structural layout of the first stator winding 121 and the second stator winding 122 and reducing the axial volume of the variable magnetic flux flywheel energy storage device 10.

[0047] Optionally, the aforementioned first stator winding 121 and the second stator winding 122 may include a stator core and a stator winding. The stator core may be stacked from silicon steel sheets to support the stator winding, provide a magnetic circuit, and reduce the hysteresis loss and eddy current loss of the stator itself when operating at high frequency, thereby improving the overall efficiency of the variable flux flywheel energy storage device 10. The stator winding is a key part of the variable flux flywheel energy storage device 10. The stator winding may be, but is not limited to, a three-phase winding, which is responsible for generating a rotating magnetic field when the variable flux flywheel energy storage device 10 is running.

[0048] Optionally, the variable magnetic flux flywheel energy storage device 10 may include a casing (not shown), the casing having a accommodating cavity, the stator 12 being arranged in the accommodating cavity and fixed to the casing, at least a portion of the structure of the rotor 11 being passed through the accommodating cavity and being suspended relative to the stator 12 under the action of the permanent magnet ring 14, thereby achieving a reasonable arrangement of the stator 12 and the rotor 11 in the accommodating cavity of the casing, and the variable magnetic flux flywheel energy storage device 10 can be carried to various scenarios to connect to external loads, thereby improving the applicability of the variable magnetic flux flywheel energy storage device 10.

[0049] Optionally, the variable flux flywheel energy storage device 10 may include a power converter (not shown) that works with the stator 12 to improve the flexibility and controllability of the variable flux flywheel energy storage device 10 and convert the output electric energy into electric energy that meets the load power supply requirements.

[0050] Optionally, the variable flux flywheel energy storage device 10 may include a heat sink (not shown). The stator 12 is installed in the housing, and a heat sink is provided outside the housing to help the variable flux flywheel energy storage device 10 dissipate heat to keep the variable flux flywheel energy storage device 10 running at a suitable temperature.

[0051] Optionally, the variable flux flywheel energy storage device 10 may include a stator frame (not shown). The stator frame is used to fix the aforementioned stator core and play a supporting and heat dissipation role. The stator frame can be made of a metal material with good heat conduction, or a heat dissipation medium can be flowed in a cooling circulation pipeline in the frame to dissipate heat.

[0052] Optionally, the variable magnetic flux flywheel energy storage device 10 may include a flywheel mechanism (not shown), which is connected to the rotor 11, so that conversion between the electrical energy of the variable magnetic flux flywheel energy storage device 10 and the mechanical energy of the flywheel mechanism can be achieved.

[0053] As shown in FIG. 5 , according to another aspect of the present application, the present application further provides a variable magnetic flux flywheel energy storage device control method, which is applied to the above-mentioned variable magnetic flux flywheel energy storage device 10. The variable magnetic flux flywheel energy storage device control method includes:

[0054] S1. When the variable magnetic flux flywheel energy storage device 10 is charged / discharged, the magnetic adjustment coil 13 is energized so that the magnetic adjustment coil 13 generates a magnetic adjustment flux, most of which passes into the leakage magnetic part 142 to occupy the space of the leakage magnetic part 142, so that the magnetic flux of the permanent magnet part is completely passed into the air gap between the rotor 11 and the stator 12.

[0055] S2. When the variable magnetic flux flywheel energy storage device 10 is on standby, a demagnetization pulse current is first passed through the magnetic adjustment coil 13 to reduce the residual magnetism of the permanent magnet part 141, and then the current of the magnetic adjustment coil 13 is reduced to 0, so that the magnetic flux of the permanent magnet part 141 flows from one end through the leakage magnetic part 142 and then returns to the other end of the permanent magnet part 141.

[0056] It is worth noting that when in standby mode, a demagnetization pulse current needs to be passed through the magnetic adjustment coil 13 first, which helps to reduce or eliminate the magnetic flux of the permanent magnet part 141 under the influence of the magnetic adjustment coil 13, and then restore the original magnetic flux of the permanent magnet part 141, so that the magnetic flux of the permanent magnet part 141 can all pass through the leakage magnetic part 142 and then return to the permanent magnet part 141.

[0057] The above-mentioned variable magnetic flux flywheel energy storage device control method is to energize the magnetic adjustment coil 13 when the variable magnetic flux flywheel energy storage device 10 is charged / discharged, so that the magnetic adjustment coil 13 generates a magnetic adjustment magnetic flux, and most of the magnetic adjustment magnetic flux is passed into the leakage magnetic part 142 to occupy the space of the leakage magnetic part 142, and then the magnetic flux of the permanent magnet part 141 is completely passed into the air gap to enhance the magnetic density of the air gap, thereby realizing the excitation effect of the variable magnetic flux flywheel energy storage device 10 during charging and discharging. In addition, when the variable magnetic flux flywheel energy storage device 10 is on standby, a demagnetization pulse current is first passed through the magnetic adjustment coil 13, which helps the magnetic adjustment coil 13 to restore the original magnetic flux, and then the current of the magnetic adjustment coil 13 is reduced to 0, so that the magnetic flux of the permanent magnet part 141 flows from one end through the leakage magnetic part 142 and then returns to the other end of the permanent magnet part 141, thereby reducing the magnetic density of the air gap in the standby state, which helps to reduce the iron loss in standby and improve the energy conversion rate of the variable magnetic flux flywheel energy storage device 10.

[0058] Optionally, the permanent magnet part 141 adopts a low coercive force permanent magnet material. It should be noted that the low coercive force permanent magnet material mainly refers to those materials that can still maintain strong magnetism after the external magnetic field is removed, but have relatively low coercive force. Coercive force refers to the reverse magnetic field strength required to reduce the magnetization intensity of the magnet to zero. In this way, by using a low coercive force permanent magnet material in the permanent magnet part 141, it helps to reduce the aforementioned reverse magnetic field strength required to reduce the magnetization intensity of the magnet to zero. In other words, the permanent magnet part 141 adopts a low coercive force permanent magnet material, which helps to reduce or eliminate the required reverse magnetic field strength of the magnetic flux applied to the permanent magnet part 141 by the magnetic adjustment coil 13. In this way, the effect of the permanent magnet part 141 restoring its original magnetic flux can be improved, making it easier for the permanent magnet part 141 to restore its original magnetic flux.

[0059] Optionally, the permanent magnet part 141 may be made of, but not limited to, samarium cobalt permanent magnet material or neodymium iron boron permanent magnet material.

[0060] Optionally, the permanent magnet portion 141 may also be made of, but not limited to, AlNiCo material, which helps to improve the low coercive force characteristics of the permanent magnet portion 141 .

[0061] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A variable magnetic flux flywheel energy storage device, characterized in that: The variable magnetic flux flywheel energy storage device includes a rotor, a stator, a magnetic adjustment coil and a permanent magnetic ring. The stator, the magnetic adjustment coil and the permanent magnetic ring are all arranged around the rotating shaft of the rotor along the circumference of the rotor. The permanent magnetic ring includes a permanent magnetic part and a leakage magnetic part alternately arranged along the circumference. There is an air gap between the stator and the rotor. The magnetic adjustment coil can generate an excitation magnetic flux in a power-on state to occupy the space of the leakage magnetic part, and make the magnetic flux of the permanent magnetic ring all pass into the air gap to enhance the magnetic density of the air gap. The magnetic flux of the permanent magnetic part can flow from one end of the permanent magnetic part through the leakage magnetic part and return to the other end of the permanent magnetic part when the magnetic adjustment coil is powered off.

2. The variable flux flywheel energy storage device according to claim 1, characterized in that: The stator includes a first stator winding and a second stator winding, the first stator winding and the second stator winding are arranged at intervals along the extension direction of the rotating shaft, and the permanent magnet ring and the magnetic adjustment coil are sandwiched between the first stator winding and the second stator winding.

3. The variable flux flywheel energy storage device according to claim 1, characterized in that: The permanent magnet part and the leakage magnetic part are integrally formed.

4. The variable flux flywheel energy storage device according to claim 1, characterized in that: The permanent magnet part is made of low coercive force permanent magnet material.

5. The variable magnetic flux flywheel energy storage device according to claim 4, characterized in that: The permanent magnet part is made of AlNiCo material.

6. The variable flux flywheel energy storage device according to claim 1, characterized in that: The magnetic leakage part is made of low magnetic resistance material.

7. The variable flux flywheel energy storage device according to claim 6, characterized in that: The magnetic leakage part is made of structural steel material.

8. The variable magnetic flux flywheel energy storage device according to claim 1, characterized in that: The variable magnetic flux flywheel energy storage device includes a casing having a receiving cavity, the stator is arranged in the receiving cavity and fixed to the casing, at least a part of the structure of the rotor is passed through the receiving cavity and is suspended relative to the stator under the action of the permanent magnet ring.

9. The variable flux flywheel energy storage device according to any one of claims 1 to 8, characterized in that: The variable magnetic flux flywheel energy storage device comprises a flywheel mechanism, and the flywheel mechanism is connected to the rotor.

10. A control method for a variable magnetic flux flywheel energy storage device, applied to the variable magnetic flux flywheel energy storage device according to any one of claims 1 to 9, characterized in that: The wheel energy storage device control method comprises: When the variable magnetic flux flywheel energy storage device is charged / discharged, the magnetic adjustment coil is energized so that the magnetic adjustment coil generates a magnetic adjustment magnetic flux, most of which flows into the magnetic leakage part to occupy the space of the magnetic leakage part, so that the magnetic flux of the permanent magnet part is completely passed into the air gap between the rotor and the stator; When the variable magnetic flux flywheel energy storage device is on standby, a demagnetization pulse current is first passed through the magnetic adjustment coil to reduce the residual magnetism of the permanent magnet part, and then the current of the magnetic adjustment coil is reduced to 0, so that the magnetic flux of the permanent magnet part flows from one end through the leakage magnetic part and then returns to the other end of the permanent magnet part.

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