Flywheel system

Abstract

The invention discloses a flywheel system. The flywheel system comprises a flywheel rotor, a speed change device, a doubly-fed asynchronous generator, a controller and an energy management device; wherein the doubly-fed asynchronous generator comprises a generator stator, a generator rotor and a frequency converter, the flywheel rotor is in transmission connection with the generator rotor through the speed change device, and the controller is respectively connected with the flywheel rotor, the speed change device, the doubly-fed asynchronous generator and the energy management device; the energy management device is used for generating a configuration instruction of the gear ratio of the speed change device according to the rotating speed of the flywheel rotor; the controller is used for configuring the gear ratio of the speed change device according to the configuration instruction so that the rotating speed of the generator rotor can be kept within a set interval. Therefore, the flywheel system can configure the speed change ratio of the speed change device according to the rotating speed of the flywheel rotor, so that the rotating speed of the generator rotor is kept in the set interval, the rotating speed of the generator rotor can be prevented from being too high or too low, and the running reliability of the flywheel system is high.

Description

Technical Field

[0001] The invention relates to the field of energy technology, and in particular to a flywheel system. Background Art

[0002] At present, flywheel energy storage technology is a kind of energy storage technology that stores energy in the form of kinetic energy. It has the advantages of fast climbing ability, high energy conversion efficiency, long service life, and easy installation, and has been widely used in the energy field. However, the flywheel system in the related technology has problems such as low flexibility and low reliability of flywheel operation. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the above-mentioned technology at least to some extent.

[0004] To this end, an object of the present invention is to propose a flywheel system, which can configure the speed ratio of the speed change device according to the rotational speed of the flywheel rotor so that the rotational speed of the generator rotor is maintained within a set range, thereby avoiding the rotational speed of the generator rotor being too high or too low, and the operating reliability of the flywheel system is relatively high.

[0005] The first aspect of the present invention proposes a flywheel system, which includes a flywheel rotor, a speed change device, a doubly fed asynchronous generator, a controller and an energy management device; wherein the doubly fed asynchronous generator includes a generator stator, a generator rotor and a frequency converter, the flywheel rotor is transmission-connected to the generator rotor through the speed change device, the generator rotor is connected to the power grid through the frequency converter, and the generator stator is connected to the power grid, and the controller is respectively connected to the flywheel rotor, the speed change device, the doubly fed asynchronous generator and the energy management device; the energy management device is used to generate a configuration instruction for the speed ratio of the speed change device according to the speed of the flywheel rotor; the controller is used to configure the speed ratio of the speed change device according to the configuration instruction so that the speed of the generator rotor is kept within a set range.

[0006] According to an embodiment of the present invention, the flywheel system includes a flywheel rotor, a speed change device, a doubly-fed asynchronous generator, a controller, and an energy management device. The energy management device is used to generate a configuration instruction for the speed ratio of the speed change device according to the rotational speed of the flywheel rotor. The controller is used to configure the speed ratio of the speed change device according to the configuration instruction so that the rotational speed of the generator rotor is kept within a set range. Thus, the flywheel system can configure the speed ratio of the speed change device according to the rotational speed of the flywheel rotor so that the rotational speed of the generator rotor is kept within a set range, which can avoid the rotational speed of the generator rotor being too high or too low, and the operation reliability of the flywheel system is high.

[0007] In addition, the flywheel system proposed in the above embodiment of the present invention may also have the following additional technical features:

[0008] In one embodiment of the present invention, the energy management device is also used to generate an adjustment instruction for the operating parameters of the generator rotor according to the rotational speed of the flywheel rotor; the controller is also used to adjust the operating parameters of the generator rotor through the inverter according to the adjustment instruction so that the magnetic field speed of the generator stator is maintained at the set speed.

[0009] In one embodiment of the present invention, the flywheel system also includes a power grid detection device, which is connected to the energy management device; the power grid detection device is used to detect power grid parameters; the energy management device is also used to generate a state switching instruction for the doubly fed asynchronous generator based on the operating parameters of the flywheel system and / or the power grid parameters; the controller is also used to switch the state of the doubly fed asynchronous generator within multiple operating states according to the state switching instruction.

[0010] In one embodiment of the present invention, the flywheel system further comprises a flywheel detection device, which is connected to the energy management device; the flywheel detection device is used to detect operating parameters of the flywheel system.

[0011] In one embodiment of the present invention, the energy management device is further configured to generate a charging instruction for the flywheel rotor in response to a rotation speed of the flywheel rotor being less than a first set threshold.

[0012] In one embodiment of the present invention, the flywheel system also includes an electric motor, which is transmission-connected to the flywheel rotor and connected to the controller; the controller is also used to control the engine to convert the first electrical energy of the power grid into first kinetic energy and control the flywheel rotor to store the first kinetic energy according to the charging instruction.

[0013] In one embodiment of the present invention, the energy management device is also used to generate a discharge instruction for the flywheel rotor in response to the rotation speed of the flywheel rotor being greater than a second set threshold, wherein the first set threshold is less than or equal to the second set threshold.

[0014] In one embodiment of the present invention, the energy management device is also used to generate a state switching instruction for the doubly-fed asynchronous generator based on at least one of the operating parameters of the flywheel system, the grid parameters, the charging instruction, and the discharging instruction.

[0015] In one embodiment of the present invention, the operating parameters of the flywheel system include at least one of the speed of the flywheel rotor and the speed of the doubly-fed asynchronous generator, and the grid parameters include at least one of the grid voltage, the grid power factor, and the grid frequency.

[0016] In one embodiment of the present invention, the flywheel system also includes a reactive compensation device, which is connected to the power grid and connected to the controller; the energy management device is also used to generate reactive compensation instructions for the reactive compensation device or the doubly fed asynchronous generator based on the operating parameters of the flywheel system and / or the power grid parameters; the controller is also used to control the reactive compensation device or the doubly fed asynchronous motor to perform reactive compensation on the power grid according to the reactive compensation instructions.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of the structure of a flywheel system according to an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of a flywheel system according to another embodiment of the present invention. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0022] The flywheel system according to the embodiment of the present invention is described below with reference to the accompanying drawings.

[0023] Figure 1 Schematic diagram of the structure of a flywheel system according to an embodiment of the present invention.

[0024] like Figure 1 As shown, the flywheel system 100 of the embodiment of the present invention includes a flywheel rotor 111, a speed change device 20, a double-fed asynchronous generator 30, a controller 70 and an energy management device 80.

[0025] The doubly-fed asynchronous generator 30 includes a generator stator, a generator rotor and a frequency converter 33. The flywheel rotor 111 is transmission-connected to the generator rotor via the speed converter 20. The generator rotor is connected to the power grid via the frequency converter 33. The generator stator is connected to the power grid. The energy management device 80 is connected to the controller 70. The controller 70 is respectively connected to the flywheel rotor 111, the speed converter 20 and the doubly-fed asynchronous generator 30.

[0026] It should be noted that the energy management device 80 is connected to the controller 70, which means that the energy management device 80 is connected to the controller 70 in communication, that is, data can be transmitted between the energy management device 80 and the controller 70. The controller 70 is connected to the flywheel rotor 111, the speed change device 20, and the doubly fed asynchronous generator 30, respectively, which means that the controller 70 is connected to the flywheel rotor 111, the speed change device 20, and the doubly fed asynchronous generator 30 in communication, that is, data can be transmitted between the controller 70 and the flywheel rotor 111, the speed change device 20, and the doubly fed asynchronous generator 30, respectively. There is no excessive limitation on the communication mode, for example, the communication connection may include wireless communication, wired communication, etc.

[0027] In one embodiment, if Figure 1 As shown, the flywheel rotor 111 is connected to the speed change device 20 via a transmission shaft 41, and the speed change device 20 is connected to the double-fed asynchronous generator 30 via a transmission shaft 42. It can be understood that the transmission shaft 41 is the input shaft of the speed change device 20, and the transmission shaft 42 is the output shaft of the speed change device 20.

[0028] In one embodiment, if Figure 1 As shown, the energy management device 80 is connected to the controller 70 via a communication line 87, the controller 70 is connected to the flywheel rotor 111 via a communication line 71, the controller 70 is connected to the speed change device 20 via a communication line 72, and the controller 70 is connected to the double-fed asynchronous generator 30 via a communication line 73.

[0029] In an embodiment of the present invention, the energy management device 80 is used to generate a configuration instruction for the speed ratio of the speed change device 20 according to the rotational speed of the flywheel rotor 111, and the controller 70 is used to configure the speed ratio of the speed change device 20 according to the configuration instruction so that the rotational speed of the generator rotor is maintained within a set range.

[0030] It should be noted that the speed change device 20 includes an input end and an output end, the flywheel rotor 111 is transmission-connected to the input end, and the output end is transmission-connected to the generator rotor. The input speed of the speed change device 20 is the speed of the flywheel rotor 111, and the output speed of the speed change device 20 is the speed of the generator rotor, that is, the speed ratio of the speed change device 20 is equal to the ratio between the speed of the flywheel rotor 111 and the speed of the generator rotor. "The speed of the generator rotor" refers to the mechanical rotation speed of the generator rotor.

[0031] It should be noted that there are no excessive restrictions on the speed ratio and the setting range. For example, the speed ratio can be any value from 0.03 to 333, and the setting range can be (2000 rpm, 4000 rpm). rpm is revolutions per minute.

[0032] In one embodiment, the energy management device 80 is used to determine the target speed ratio of the speed change device 20 according to the speed of the flywheel rotor and the set interval, and generate a configuration instruction for the speed ratio of the speed change device 20 based on the target speed ratio. It can be understood that when the speed ratio of the speed change device 20 is the target speed ratio, the speed of the generator rotor can be kept within the set interval. For example, when the speed of the flywheel rotor 111 is 1000rpm and the set interval is (2000rpm, 4000rpm), the target speed ratio can be any value between 0.25 and 0.5. For example, the target speed ratio can be 0.3 or 0.4.

[0033] In one embodiment, the energy management device 80 is used to select a target speed ratio from a plurality of candidate speed ratios of the speed change device 20 according to the speed of the flywheel rotor 111, and generate a configuration instruction of the speed ratio of the speed change device 20 based on the target speed ratio. It is understandable that a plurality of candidate speed ratios can be pre-configured for the speed change device 20. For example, when the speed of the flywheel rotor 111 is 1000 rpm and the setting interval is (2000 rpm, 4000 rpm), it can be known that the target speed ratio can be any value between 0.25 and 0.5. If the candidate speed ratios include 0.1, 0.3, 0.8, and 1, the target speed ratio of 0.3 can be selected from the candidate speed ratios.

[0034] In one embodiment, the flywheel system 100 further includes a flywheel detection device, which is connected to the energy management device 80, and is used to detect the operating parameters of the flywheel system. It should be noted that the connection between the flywheel detection device and the energy management device 80 means that the flywheel detection device and the energy management device 80 are in communication connection, that is, data can be transmitted between the flywheel detection device and the energy management device 80. There are no excessive restrictions on the operating parameters of the flywheel system. For example, the operating parameters of the flywheel system include but are not limited to the speed of the flywheel rotor, the speed of the doubly-fed asynchronous generator, etc.

[0035] In one embodiment, the flywheel detection device may include a speed sensor, which may be arranged on the flywheel rotor 111 and the doubly-fed asynchronous generator 30 to detect the speed of the flywheel rotor 111 and the speed of the doubly-fed asynchronous generator 30 respectively.

[0036] It should be noted that no excessive limitations are imposed on the speed change device 20 , the double-fed asynchronous generator 30 , and the frequency converter 33 .

[0037] In one embodiment, the speed transmission device 20 includes but is not limited to a continuously variable speed transmission device, a permanent magnet speed transmission device, a hydraulic speed transmission device, a magnetorheological fluid device, a gear transmission speed transmission device, a magnetic coupling speed transmission device, a speed transmission device with adjustable speed difference, and a doubly fed asynchronous adjustable speed transmission device.

[0038] In one embodiment, the inverter 33 may include a bidirectional back-to-back IGBT (Insulated Gate Bipolar Transistor) voltage source inverter.

[0039] In summary, the flywheel system of the embodiment of the present invention includes a flywheel rotor, a speed change device, a doubly-fed asynchronous generator, a controller and an energy management device. The energy management device is used to generate a configuration instruction of the speed ratio of the speed change device according to the rotational speed of the flywheel rotor. The controller is used to configure the speed ratio of the speed change device according to the configuration instruction so that the rotational speed of the generator rotor is kept within a set range. Therefore, the flywheel system can configure the speed ratio of the speed change device according to the rotational speed of the flywheel rotor so that the rotational speed of the generator rotor is kept within a set range, which can avoid the rotational speed of the generator rotor being too high or too low, and the operation reliability of the flywheel system is high.

[0040] Based on any of the above embodiments, the energy management device 80 is also used to generate adjustment instructions for the operating parameters of the generator rotor according to the rotational speed of the flywheel rotor 111, and the controller 70 is also used to adjust the operating parameters of the generator rotor through the inverter 33 according to the adjustment instructions so that the magnetic field speed of the generator stator is maintained at the set speed.

[0041] It should be noted that the "magnetic field speed of the generator stator" is not the mechanical rotation speed. The magnetic field speed of the generator stator is maintained at the set speed, so that the double-fed asynchronous generator 30 generates electric energy of the set frequency, and then the double-fed asynchronous motor 30 outputs electric energy of the set frequency to the power grid. There are no excessive restrictions on the set speed and set frequency. For example, the set speed is 3000rpm (revolutions per minute) and the set frequency is 50Hz (hertz).

[0042] It should be noted that the magnetic field speed of the generator stator = the speed of the flywheel rotor 111 + the magnetic field speed matched by the operating parameters of the generator rotor. Among them, the speed of the flywheel rotor 111 is equal to the mechanical speed of the generator rotor. There are no excessive restrictions on the operating parameters of the generator rotor. For example, the operating parameters of the generator rotor include but are not limited to the frequency, voltage, amplitude, phase, etc. of the generator rotor. For example, taking the operating parameter of the generator rotor as the current frequency of the generator rotor as an example, the magnetic field speed of the generator stator = the speed of the flywheel rotor 111 + the magnetic field speed matched by the current frequency of the generator rotor.

[0043] In one embodiment, the energy management device 80 is also used to determine the magnetic field speed that matches the operating parameters of the generator rotor based on the magnetic field speed of the generator stator and the speed of the flywheel rotor 111, determine the target value of the operating parameters of the generator rotor based on the magnetic field speed that matches the operating parameters of the generator rotor, and generate adjustment instructions for the operating parameters of the generator rotor based on the target value of the operating parameters of the generator rotor.

[0044] In one embodiment, the energy management device 80 is further used to obtain the difference between the magnetic field speed of the generator stator and the speed of the flywheel rotor 111, and determine the difference as the magnetic field speed that matches the operating parameters of the generator rotor.

[0045] In one embodiment, the magnetic field speed matched by the operating parameters of the generator rotor and the target value of the operating parameters of the generator rotor are in a preset corresponding relationship. For example, the double-fed asynchronous generator 30 may be parameter-calibrated to establish a corresponding relationship between the magnetic field speed matched by the operating parameters of the generator rotor and the target value of the operating parameters of the generator rotor. For example, taking the operating parameter of the generator rotor as the current frequency of the generator rotor as an example, a corresponding relationship between the magnetic field speed matched by the current frequency of the generator rotor and the target value of the current frequency of the generator rotor may be established.

[0046] In one embodiment, the energy management device 80 is also used to use the magnetic field speed matching the operating parameters of the generator rotor as a query key value, query in a preset corresponding relationship, and determine the queried target value as the target value of the operating parameters of the generator rotor.

[0047] Therefore, the flywheel system of the embodiment of the present invention can adjust the operating parameters of the generator rotor according to the rotational speed of the flywheel rotor so that the magnetic field speed of the generator stator is maintained at a set rotational speed, which can ensure that the doubly-fed asynchronous generator generates electrical energy of a set frequency, and then enable the doubly-fed asynchronous motor to output electrical energy of a set frequency to the power grid, which helps to improve the stability of the power grid.

[0048] Based on any of the above embodiments, Figure 1 As shown, the flywheel system 100 of the embodiment of the present invention further includes a power grid detection device 60 , and the power grid detection device 60 is connected to the energy management device 80 .

[0049] It should be noted that the connection between the power grid detection device 60 and the energy management device 80 means that the power grid detection device 60 and the energy management device 80 are in communication connection, that is, data can be transmitted between the power grid detection device 60 and the energy management device 80. For the relevant contents of the communication connection, please refer to the above embodiment and will not be repeated here.

[0050] In one embodiment, if Figure 1As shown, the power grid detection device 60 is connected to the energy management device 80 via a communication line 86 .

[0051] In the embodiment of the present invention, the power grid detection device 60 is used to detect power grid parameters, the energy management device 80 is also used to generate a state switching instruction of the double-fed asynchronous generator 30 according to the operating parameters of the flywheel system and / or the power grid parameters, and the controller 70 is also used to switch the state of the double-fed asynchronous generator 30 within multiple operating states according to the state switching instruction. It should be noted that the relevant content of the operating parameters of the flywheel system can be referred to the above embodiment, and will not be repeated here. There is no excessive limitation on the power grid parameters. For example, the power grid parameters include but are not limited to the power grid voltage, power grid power factor, power grid frequency, etc.

[0052] In one embodiment, the power grid detection device 60 may include a voltage sensor and a power sensor, wherein the voltage sensor is used to detect the power grid voltage and power grid frequency, and the power sensor is used to detect the power grid power factor. For example, the double-fed asynchronous generator 30 is connected to the power grid through an access device, and the power grid detection device 60 may be set on the access device. It should be noted that there is no excessive limitation on the access device, for example, the access device includes but is not limited to a transmission line, a transformer, etc.

[0053] It should be noted that in the embodiment of the present invention, the doubly-fed asynchronous generator 30 may have multiple operating states, and there are no excessive restrictions on the operating states. For example, the operating states include but are not limited to phase adjustment state, motor state, generator state, standby state, etc.

[0054] When the operation state of the double-fed asynchronous generator 30 is the phase adjustment state, the double-fed asynchronous generator 30 outputs reactive power to the power grid or absorbs reactive power from the power grid.

[0055] When the operation state of the double-fed asynchronous generator 30 is the motor state, the double-fed asynchronous generator 30 converts the first electric energy of the grid into the first kinetic energy, that is, at this time, the double-fed asynchronous generator 30 absorbs electric energy from the grid.

[0056] Among them, when the operating state of the doubly-fed asynchronous generator 30 is the generator state, the doubly-fed asynchronous generator 30 converts the second kinetic energy of the flywheel rotor into the second electric energy of the set frequency, and outputs the second electric energy to the power grid, that is, at this time, the doubly-fed asynchronous generator 30 outputs the electric energy of the set frequency to the power grid. It should be noted that there is no excessive limitation on the set frequency, for example, the set frequency is 50 Hz (Hertz). It can be understood that the magnetic field speed of the generator stator is maintained at the set speed, so that the doubly-fed asynchronous generator 30 generates electric energy of the set frequency.

[0057] Among them, when the operating state of the double-fed asynchronous generator 30 is the standby state, the double-fed asynchronous generator 30 remains connected to the power grid, does not output reactive power to the power grid, does not absorb reactive power from the power grid, does not absorb electric energy from the power grid, and does not output electric energy to the power grid, that is, does not perform any action.

[0058] In one embodiment, the energy management device 80 is further used to identify the switching condition that currently satisfies the target operating state according to the operating parameters and / or the grid parameters, and generate a state switching instruction for the double-fed asynchronous generator 30, wherein the state switching instruction is used to instruct the operating state of the double-fed asynchronous generator 30 to switch to the target operating state. It should be noted that there are no excessive restrictions on the switching conditions. It is understandable that different operating states may correspond to different switching conditions.

[0059] In one embodiment, a mapping relationship or a mapping table between the operating state and the switching condition may be pre-established. For example, the mapping relationship or the mapping table may be pre-set in the storage space of the flywheel system 100, for example, the storage space of the flywheel system 100 may include the storage space of the energy management device 80.

[0060] Therefore, the flywheel system of the embodiment of the present invention can comprehensively consider the operating parameters and / or grid parameters of the flywheel system, and switch the state of the double-fed asynchronous generator within multiple operating states, which helps to improve the switching accuracy and flexibility of the operating state of the double-fed asynchronous generator, and the operating reliability of the flywheel system is relatively high.

[0061] Based on any of the above embodiments, the energy management device 80 is also used to generate a charging instruction for the flywheel rotor 111 in response to the rotation speed of the flywheel rotor 111 being less than a first set threshold, indicating that the rotation speed of the flywheel rotor 111 is low.

[0062] In one embodiment, the energy management device 80 is also used to generate a discharge instruction for the flywheel rotor 111 in response to the rotation speed of the flywheel rotor 111 being greater than a second set threshold, indicating that the rotation speed of the flywheel rotor 111 is relatively high, wherein the first set threshold is less than or equal to the second set threshold.

[0063] It should be noted that there are no excessive restrictions on the first set threshold and the second set threshold. For example, the first set threshold is the minimum speed allowed by the flywheel rotor 111, and the first set threshold is 100 rpm (revolutions per minute). The second set threshold is the maximum speed allowed by the flywheel rotor 111, and the second set threshold is 1000000 rpm.

[0064] Therefore, the flywheel system of the embodiment of the present invention can automatically generate a charging instruction or a discharging instruction for the flywheel rotor according to the rotational speed of the flywheel rotor, which can effectively prevent the rotational speed of the flywheel rotor from being too low or too high, so that the rotational speed of the flywheel rotor is maintained within a reasonable range, and the operating reliability of the flywheel system is relatively high.

[0065] Based on any of the above embodiments, Figure 2 As shown, the flywheel system 100 of the embodiment of the present invention further includes an electric motor 112 , which is transmission-connected to the flywheel rotor 111 , and the electric motor 112 is connected to the controller 70 .

[0066] In one embodiment, if Figure 2 As shown, the electric motor 112 is connected to the flywheel rotor 111 via a transmission shaft 41 .

[0067] It should be noted that the connection between the motor 112 and the controller 70 means that the motor 112 and the controller 70 are in communication connection, that is, data can be transmitted between the motor 112 and the controller 70. For the relevant contents of the communication connection, please refer to the above embodiment, which will not be repeated here.

[0068] In one embodiment, if Figure 2 As shown, the motor 112 is connected to the controller 70 via a communication link 74 .

[0069] In the embodiment of the present invention, the controller 70 is also used to control the engine 112 to convert the first electrical energy of the power grid into the first kinetic energy according to the charging instruction, and control the flywheel rotor 111 to store the first kinetic energy. It can be understood that at this time, the motor 112 can drive the speed of the flywheel rotor 111 to increase, that is, controlling the flywheel rotor 111 to store the first kinetic energy can be achieved by increasing the speed of the flywheel rotor 111. It should be noted that the relevant content of the charging instruction can be referred to the above embodiment, and will not be repeated here.

[0070] Therefore, the flywheel system of the embodiment of the present invention also includes an electric motor, which is transmission-connected to the flywheel rotor, and the electric motor is connected to the controller. According to the charging instruction of the flywheel rotor, the electric motor can be controlled to convert the first electrical energy of the power grid into the first kinetic energy, and the flywheel rotor can be controlled to store the first kinetic energy to adjust the rotation speed of the flywheel rotor. This can effectively prevent the rotation speed of the flywheel rotor from being too low, so that the rotation speed of the flywheel rotor is maintained within a reasonable range, and the operation reliability of the flywheel system is relatively high.

[0071] Based on any of the above embodiments, the energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 according to at least one of the operating parameters of the flywheel system, grid parameters, charging instructions, and discharging instructions.

[0072] In one embodiment, the energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 in response to the rotational speed of the flywheel rotor 111 being less than a first set threshold value, and / or a charging instruction of the flywheel rotor 111, wherein the state switching instruction is used to instruct the operating state of the doubly-fed asynchronous generator 30 to switch to an electric motor state.

[0073] In one embodiment, the energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 in response to the rotational speed of the flywheel rotor 111 being greater than a second set threshold value, and / or a discharge instruction of the flywheel rotor 111, wherein the state switching instruction is used to instruct the operating state of the doubly-fed asynchronous generator 30 to switch to a generator state.

[0074] In one embodiment, the energy management device 80 is further used to generate a state switching instruction of the double-fed asynchronous generator 30 in response to the grid voltage being less than the third set threshold value and / or the grid power factor being greater than the fourth set threshold value, wherein the state switching instruction is used to instruct the operation state of the double-fed asynchronous generator 30 to switch to the first phase adjustment state. When the operation state of the double-fed asynchronous generator 30 is the first phase adjustment state, the double-fed asynchronous generator 30 outputs reactive power to the grid.

[0075] In one embodiment, the energy management device 80 is further used to generate a state switching instruction of the double-fed asynchronous generator 30 in response to the grid voltage being greater than the fifth set threshold value and / or the grid power factor being less than the sixth set threshold value, wherein the state switching instruction is used to instruct the operation state of the double-fed asynchronous generator 30 to switch to the second phase adjustment state. When the operation state of the double-fed asynchronous generator 30 is the second phase adjustment state, the double-fed asynchronous generator 30 absorbs reactive power from the grid.

[0076] It should be noted that the third set threshold is less than or equal to the fifth set threshold, and the sixth set threshold is less than or equal to the fourth set threshold. There are no excessive restrictions on the third to sixth set thresholds. For example, the third set threshold is the lowest voltage allowed by the power grid, the fourth set threshold is the highest power factor allowed by the power grid, the fifth set threshold is the highest voltage allowed by the power grid, and the sixth set threshold is the lowest power factor allowed by the power grid.

[0077] In one embodiment, the energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 in response to the grid frequency being less than a seventh set threshold, wherein the state switching instruction is used to instruct the operating state of the doubly-fed asynchronous generator 30 to switch to a generator state.

[0078] In one embodiment, the energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 in response to the grid frequency being greater than an eighth set threshold, wherein the state switching instruction is used to instruct the operating state of the doubly-fed asynchronous generator 30 to switch to a motor state.

[0079] It should be noted that the seventh setting threshold is less than or equal to the eighth setting threshold. There are no excessive restrictions on the seventh setting threshold and the eighth setting threshold. For example, the seventh setting threshold and the eighth setting threshold are both 50 Hz.

[0080] It should be noted that the rotational speed of the doubly-fed asynchronous generator 30 is positively correlated with the grid frequency. The energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 in response to the rotational speed of the doubly-fed asynchronous generator 30 being less than a set threshold value 143, indicating that the grid frequency is low, wherein the state switching instruction is used to instruct the operating state of the doubly-fed asynchronous generator 30 to switch to a generator state.

[0081] In one embodiment, the energy management device 80 is also used to generate a state switching instruction for the doubly-fed asynchronous generator 30 in response to the rotation speed of the doubly-fed asynchronous generator 30 being greater than a fourteenth set threshold, indicating that the grid frequency is high, wherein the state switching instruction is used to instruct the operating state of the doubly-fed asynchronous generator 30 to switch to a motor state.

[0082] It should be noted that the 143rd setting threshold is less than or equal to the 14th setting threshold. There are no excessive restrictions on the 143rd setting threshold and the 14th setting threshold. For example, the 143rd setting threshold and the 14th setting threshold are 3000 rpm.

[0083] Therefore, the flywheel system of the embodiment of the present invention can comprehensively consider at least one of the operating parameters, grid parameters, charging instructions, and discharging instructions of the flywheel system, and switch the state of the double-fed asynchronous generator within multiple operating states, which helps to improve the switching accuracy and flexibility of the operating state of the double-fed asynchronous generator, and the operating reliability of the flywheel system is relatively high.

[0084] Based on any of the above embodiments, Figure 2 As shown, the flywheel system 100 of the embodiment of the present invention further includes a reactive power compensation device 110 . The reactive power compensation device 110 is connected to the power grid, and the reactive power compensation device 110 is connected to the controller 70 .

[0085] It should be noted that the connection between the reactive power compensation device 110 and the controller 70 means that the reactive power compensation device 110 and the controller 70 are in communication connection, that is, data can be transmitted between the reactive power compensation device 110 and the controller 70. For the relevant contents of the communication connection, please refer to the above embodiment, which will not be repeated here.

[0086] In one embodiment, if Figure 2 As shown, the reactive power compensation device 110 is connected to the controller 70 via a communication line 711 .

[0087] In an embodiment of the present invention, the energy management device 80 is further used to generate reactive compensation instructions for the reactive compensation device 110 or the doubly-fed asynchronous generator 30 according to the operating parameters of the flywheel system and / or the grid parameters.

[0088] The controller 70 is also used to control the reactive power compensation device 110 or the double-fed asynchronous motor 30 to perform reactive power compensation on the power grid according to the reactive power compensation instruction.

[0089] In one embodiment, the energy management device 80 is also used to generate a reactive compensation instruction for the reactive compensation device in response to the grid voltage being less than a third set threshold and / or the grid power factor being greater than a fourth set threshold, wherein the reactive compensation instruction for the reactive compensation device is used to instruct the reactive compensation device to output reactive power to the grid.

[0090] In one embodiment, the energy management device 80 is also used to generate a reactive compensation instruction for the reactive compensation device in response to the grid voltage being greater than a fifth set threshold and / or the grid power factor being less than a sixth set threshold, wherein the reactive compensation instruction for the reactive compensation device is used to instruct the reactive compensation device to absorb reactive power from the grid.

[0091] In one embodiment, the energy management device 80 is also used to generate a reactive power compensation instruction for the doubly-fed asynchronous generator in response to the grid voltage being greater than or equal to a third set threshold and less than a ninth set threshold, and / or the grid power factor being less than or equal to a fourth set threshold and greater than a tenth set threshold, wherein the reactive power compensation instruction for the doubly-fed asynchronous generator is used to instruct the doubly-fed asynchronous generator to output reactive power to the grid.

[0092] In one embodiment, the energy management device 80 is also used to generate a reactive power compensation instruction for the doubly-fed asynchronous generator in response to the grid voltage being less than or equal to a fifth set threshold and greater than an eleventh set threshold, and / or the grid power factor being greater than or equal to a sixth set threshold and less than a twelfth set threshold, wherein the reactive power compensation instruction for the doubly-fed asynchronous generator is used to instruct the doubly-fed asynchronous generator to absorb reactive power from the grid.

[0093] It should be noted that the ninth setting threshold is less than or equal to the eleventh setting threshold, and the twelfth setting threshold is less than or equal to the tenth setting threshold. There are no excessive restrictions on the ninth to twelfth setting thresholds. For example, the ninth setting threshold is the minimum voltage allowed for the doubly-fed asynchronous generator to perform reactive power compensation, the tenth setting threshold is the maximum power factor allowed for the doubly-fed asynchronous generator to perform reactive power compensation, the eleventh setting threshold is the maximum voltage allowed for the doubly-fed asynchronous generator to perform reactive power compensation, and the twelfth setting threshold is the minimum power factor allowed for the doubly-fed asynchronous generator to perform reactive power compensation.

[0094] Therefore, the flywheel system of the embodiment of the present invention also includes a reactive compensation device, which is connected to the power grid. The reactive compensation device is connected to a controller. The operating parameters of the flywheel system and / or the power grid parameters can be comprehensively considered to control the reactive compensation device or the doubly-fed asynchronous generator to perform reactive compensation on the power grid, which helps to improve the stability of the power grid and ensure the normal operation of the flywheel system.

[0095] It should be noted that Figure 1 , 2 The flywheel system shown is only an example of the flywheel system in the embodiment of the present invention, and is not a limitation of the flywheel system in the embodiment of the present invention.

[0096] In the description of the present invention, it should be understood that 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0097] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0098] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0099] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a 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. A first feature being "below", "below" or "below" a 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.

[0100] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0101] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A flywheel system, characterized in that: The flywheel system includes a flywheel rotor, a speed change device, a double-fed asynchronous generator, a controller and an energy management device; wherein, The doubly-fed asynchronous generator comprises a generator stator, a generator rotor and a frequency converter, the flywheel rotor is drivingly connected to the generator rotor through the speed converter, the generator rotor is connected to the power grid through the frequency converter, the generator stator is connected to the power grid, and the controller is respectively connected to the flywheel rotor, the speed converter, the doubly-fed asynchronous generator and the energy management device; The energy management device is used to generate a configuration instruction for the speed ratio of the speed change device according to the rotation speed of the flywheel rotor; The controller is used to configure the speed ratio of the speed change device according to the configuration instruction so that the rotation speed of the generator rotor is maintained within a set range.

2. The flywheel system according to claim 1, characterized in that: The energy management device is also used to generate an adjustment instruction for the operating parameters of the generator rotor according to the rotation speed of the flywheel rotor; The controller is also used to adjust the operating parameters of the generator rotor through the frequency converter according to the adjustment instruction, so that the magnetic field speed of the generator stator is maintained at a set speed.

3. The flywheel system according to claim 1, characterized in that: The flywheel system further comprises a power grid detection device, wherein the power grid detection device is connected to the energy management device; The power grid detection device is used to detect power grid parameters; The energy management device is also used to generate a state switching instruction for the double-fed asynchronous generator according to the operating parameters of the flywheel system and / or the grid parameters; The controller is also used to switch the state of the double-fed asynchronous generator within multiple operating states according to the state switching instruction.

4. The flywheel system according to claim 3, characterized in that: The flywheel system further comprises a flywheel detection device, wherein the flywheel detection device is connected to the energy management device; The flywheel detection device is used to detect the operating parameters of the flywheel system.

5. The flywheel system according to claim 1, characterized in that: The energy management device is also used to generate a charging instruction for the flywheel rotor in response to the rotation speed of the flywheel rotor being less than a first set threshold.

6. The flywheel system according to claim 5, characterized in that The flywheel system further comprises an electric motor, which is drivingly connected to the flywheel rotor and connected to the controller; The controller is also used to control the engine to convert the first electrical energy of the power grid into first kinetic energy according to the charging instruction, and control the flywheel rotor to store the first kinetic energy.

7. The flywheel system according to claim 5, characterized in that The energy management device is also used to generate a discharge instruction for the flywheel rotor in response to the rotation speed of the flywheel rotor being greater than a second set threshold, wherein the first set threshold is less than or equal to the second set threshold.

8. The flywheel system according to claim 7, characterized in that The energy management device is also used to generate a state switching instruction for the double-fed asynchronous generator based on at least one of the operating parameters of the flywheel system, the grid parameters, the charging instruction, and the discharging instruction.

9. The flywheel system according to any one of claims 3 to 8, characterized in that: The operating parameters of the flywheel system include at least one of the rotational speed of the flywheel rotor and the rotational speed of the doubly-fed asynchronous generator, and the grid parameters include at least one of the grid voltage, the grid power factor, and the grid frequency.

10. The flywheel system according to any one of claims 3 to 8, characterized in that: The flywheel system further comprises a reactive power compensation device, the reactive power compensation device is connected to the power grid, and the reactive power compensation device is connected to the controller; The energy management device is also used to generate a reactive compensation instruction for the reactive compensation device or the double-fed asynchronous generator according to the operating parameters of the flywheel system and / or the grid parameters; The controller is also used to control the reactive compensation device or the double-fed asynchronous motor to perform reactive compensation on the power grid according to the reactive compensation instruction.

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