WO2023088321A1 - 具有电磁耦合器的飞轮储能*** - Google Patents
具有电磁耦合器的飞轮储能*** Download PDFInfo
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- WO2023088321A1 WO2023088321A1 PCT/CN2022/132334 CN2022132334W WO2023088321A1 WO 2023088321 A1 WO2023088321 A1 WO 2023088321A1 CN 2022132334 W CN2022132334 W CN 2022132334W WO 2023088321 A1 WO2023088321 A1 WO 2023088321A1
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- rotor
- flywheel
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- energy storage
- outer rotor
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J15/00—Systems for storing electric energy
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/30—Arrangements for balancing of the load in a network by storage of energy using dynamo-electric machines coupled to flywheels
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
- H02K49/10—Dynamo-electric clutches; Dynamo-electric brakes of the permanent-magnet type
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/02—Additional mass for increasing inertia, e.g. flywheels
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids
Definitions
- the present disclosure relates to the technical field of energy storage, in particular to a flywheel energy storage system with an electromagnetic coupler.
- connection of a high proportion of power electronic devices will cause the power grid to remain at a low inertia level for a long time, increasing the unbalanced power impact of the system, which brings more and more pressure to the safe and stable operation of the power system.
- an energy storage system with a certain ability to support the dynamic adjustment of the power grid is urgently needed to improve the ability of the power grid to efficiently accept new energy.
- Flywheel energy storage technology is an energy storage technology that stores energy in the form of kinetic energy.
- the energy storage/release is realized by the motor/generator driving the rotor to accelerate/decelerate.
- the main advantages of flywheel energy storage are fast climbing ability, high energy conversion efficiency and long service life, etc. It has unique advantages in providing auxiliary services, such as inertia and frequency regulation.
- the flywheel does not have any geographical restrictions, can be easily installed, and has the advantages of being scalable and replicable on a large scale.
- flywheel energy storage technologies all use power electronic devices to assist the motor/generator in the process of mutual conversion between kinetic energy and electric energy.
- the system When the system needs to store electric energy, it will supply the external AC power to the motor through AC/DC, and then drive the flywheel rotor to rotate and store energy; when it needs to discharge, the power electronic device decouples the rotor inertia of the flywheel rotor , Play the role of rectification, frequency modulation and voltage stabilization to meet the power demand of the load.
- power electronic devices do not have moment of inertia, so it is difficult to participate in grid inertia response. Therefore, flywheel energy storage technology cannot solve the problem that the proportion of total moment of inertia in the current grid is constantly decreasing due to the large-scale use of power electronic devices.
- the present disclosure aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present disclosure proposes a flywheel energy storage system with an electromagnetic coupler.
- a flywheel energy storage system with an electromagnetic coupler includes a motor, a flywheel rotor, an electromagnetic coupler, a frequency converter, and a generator, the motor is connected to the flywheel rotor to drive the flywheel rotor to rotate, and the electromagnetic
- the coupler includes an outer rotor and an inner rotor, the outer rotor sleeves the inner rotor and is spaced from the inner rotor; the flywheel rotor is in drive connection with the outer rotor, and the outer rotor generates a rotating magnetic field to drive the The inner rotor rotates, the frequency converter is connected with the outer rotor to keep the rotational speed of the rotating magnetic field constant, so that the inner rotor speed remains constant, and the inner rotor is connected to the input end of the generator connected, the generator generates electricity and connects to the power grid and inputs electric energy with a stable frequency into the power grid; or, the flywheel rotor is connected to the inner rotor through transmission, and the inner rotor generates
- the flywheel rotor of the flywheel energy storage system is connected to the electromagnetic coupler with variable speed function, and the output speed of the electromagnetic coupler can remain unchanged, so it can drive the generator to generate constant frequency current to meet the requirements of power transmission to the grid Require. Since the electromagnetic coupler has a variable speed function, the change in the rotational speed of the flywheel rotor will not affect the input of constant frequency current from the generator to the grid.
- the flywheel energy storage system provided by the embodiment of the present disclosure is connected to the grid without using power electronic devices for decoupling, Rectification, frequency modulation, and voltage stabilization solve the problem that the total moment of inertia caused by the use of power electronic devices in the current power grid is continuously reduced, and can increase the moment of inertia in the power grid, provide the necessary voltage and frequency support for the power grid, and reduce the The risk of large frequency deviations in the power grid enables the power system to operate safely and stably, and improves the ability of the grid to efficiently accept new energy.
- the inner rotor includes an inner rotor core and an inner rotor winding
- the outer rotor includes an outer rotor iron core and an outer rotor winding
- the frequency converter is connected to the outer rotor winding.
- the generator is a synchronous generator.
- the electric motor is connected to the grid and used to take power from the grid
- the flywheel energy storage system has an energy release state and an energy storage state
- the motor In the state of energy release, the motor is on standby, the flywheel rotor releases kinetic energy to drive the generator to generate electricity, and the generator inputs electric energy with a stable frequency to the grid,
- the electric motor takes power from the grid to drive the flywheel rotor to rotate, and the generator runs idly.
- the flywheel energy storage system has a standby state, and in the standby state, the electric motor is on standby and the generator is idling.
- the flywheel energy storage system further includes a transmission device, the flywheel rotor is in transmission connection with the input end of the transmission device, and the output end of the transmission device is in transmission connection with the outer rotor or the inner rotor,
- the speed change device is used to transfer the moment of inertia of the flywheel rotor.
- the transmission device is a transmission device with a fixed transmission ratio, or the transmission device is a transmission device with an adjustable transmission ratio.
- the transmission device is a gear transmission, a torque converter, a magnetic transformer or a permanent magnet transmission.
- the rotation speed of the flywheel rotor is 100rpm-1000000rpm, and the transmission ratio of the transmission device is 0.03-333.
- Fig. 1 is a schematic diagram of a flywheel energy storage system according to Embodiment 1 of the present disclosure.
- FIG. 2 is a partial schematic diagram of FIG. 1 .
- Fig. 3 is a schematic diagram of a flywheel energy storage system according to Embodiment 2 of the present disclosure.
- Fig. 4 is a schematic diagram of a flywheel energy storage system according to Embodiment 3 of the present disclosure.
- Fig. 5 is a schematic diagram of a flywheel energy storage system according to Embodiment 4 of the present disclosure.
- FIG. 6 is a partial schematic diagram of FIG. 5 .
- Fig. 7 is a schematic diagram of a flywheel energy storage system according to Embodiment 5 of the present disclosure.
- Fig. 8 is a schematic diagram of a flywheel energy storage system according to Embodiment 6 of the present disclosure.
- FIG. 9 is a schematic diagram of a flywheel energy storage controller according to an embodiment of the disclosure.
- Flywheel energy storage system 1 motor 10, flywheel rotor 20, electromagnetic coupler 30, outer rotor 31, inner rotor 32, frequency converter 40, generator 50, constant speed ratio transmission device 61, speed ratio adjustable device 62, first A transmission shaft 71 , a second transmission shaft 72 , and a third transmission shaft 73 .
- a flywheel energy storage system 1 includes a motor 10 , a flywheel rotor 20 , an electromagnetic coupler 30 , a frequency converter 40 and a generator 50 .
- the flywheel rotor 20 can realize energy storage, and deceleration of the flywheel rotor 20 can realize energy release.
- the flywheel rotor 20 is connected with the motor 10, and the motor 10 is used to drive the flywheel rotor 20 to rotate.
- the electric motor 10 accelerates the rotation by driving the flywheel rotor 20 , and finally the electric energy is stored in the flywheel energy storage unit 10 in the form of kinetic energy.
- the motor 10 is connected to the grid for taking power from the grid, and the motor 10 takes power from the grid to drive the flywheel rotor 20 to rotate, and the speed of the flywheel rotor 20 increases to store kinetic energy.
- the electromagnetic coupler 30 includes an outer rotor 31 and an inner rotor 32 , the outer rotor 31 sleeves the inner rotor 32 , and the outer rotor 31 and the inner rotor 32 are spaced apart.
- the flywheel rotor 20 is in drive connection with the outer rotor 31, and the outer rotor 31 generates a rotating magnetic field to drive the inner rotor 32 to rotate.
- the rotational speed of the rotor 32 can be kept constant.
- the inner rotor 32 is connected to the input end of the generator 50. Since the rotational speed of the inner rotor 32 can be kept constant, the generator 50 generates electricity and connects it to the grid and inputs electric energy with a stable frequency into the grid.
- the ratio of the mechanical speed of the outer rotor 31 to the mechanical speed of the inner rotor 32 can be regarded as the transmission ratio of the electromagnetic coupler 30, so the electromagnetic coupler 30 can be regarded as a transmission device with variable transmission ratio.
- the outer rotor 31 When the frequency converter 40 inputs alternating current to the outer rotor 31, the outer rotor 31 can generate a rotating magnetic field. In addition, because the outer rotor 31 rotates, the rotational speed of the rotating magnetic field actually generated by the outer rotor 31 is the rotational speed of the rotating magnetic field matched by the current supplied by the frequency converter 40. Superimposed with the mechanical rotational speed of the outer rotor 31, the inner rotor 32 rotates under the action of the rotating magnetic field, and the rotational speed of the inner rotor 32 is equal to the magnetic field rotational speed of the outer rotor 31, thereby realizing the transmission of the moment of inertia.
- the magnetic field speed matching the current can be changed, so that the outer rotor 31
- the rotation speed of the magnetic field is constant, so that the rotation speed of the inner rotor 32 remains constant, and the inner rotor 32 drives the generator 50 to input current with a stable frequency to the grid.
- the electromagnetic coupler 30 has the function of variable speed, and through the function of the electromagnetic coupler 30 , the generator 50 can input constant frequency current to the power grid.
- the stable input of electric energy by the generator 50 to the grid is not affected by changes in the rotational speed of the flywheel rotor 20 , even if the rotational speed of the flywheel rotor 20 changes, the generator 50 can stably input electric energy to the grid.
- the rotational speed of the inner rotor 32 is 3000 rpm, and the generator 50 can stably input current with a frequency of 50 Hz to the grid.
- the flywheel energy storage system 1 can be connected to the grid to participate in the grid inertia response, store the overflow energy in the flywheel rotor 20 according to the overflow ratio, or draw energy from the flywheel rotor 20 according to the missing ratio to supplement the grid, reducing grid frequency fluctuations.
- the flywheel rotor 20 is connected with the inner rotor 32 in transmission, the flywheel rotor 20 is driven to drive the inner rotor 32 to rotate, and the rotation of the inner rotor 32 generates a rotating magnetic field to drive the outer rotor 32 to rotate.
- the frequency converter 40 is connected with the outer rotor 31, and the frequency converter 40 is used to change the frequency of the current passing into the outer rotor 31, thereby changing the magnetic field speed matched by the current passing into the outer rotor 31, so that the mechanical speed of the outer rotor 31 can be kept constant.
- the outer rotor 31 is connected to the input end of the generator 50.
- the generator 50 Since the mechanical speed of the outer rotor 31 can be kept constant, the generator 50 generates electricity and connects to the power grid and inputs electric energy with a stable frequency into the power grid.
- the ratio of the mechanical speed of the inner rotor 32 to the mechanical speed of the outer rotor 31 can be regarded as the transmission ratio of the electromagnetic coupler 30, so the electromagnetic coupler 30 can be regarded as a transmission device with variable transmission ratio.
- the rotation of the flywheel rotor 20 can drive the inner rotor 32 to rotate.
- the rotation of the inner rotor 32 generates a rotating magnetic field, and the rotation speed of the rotation field of the inner rotor 32 is equal to the mechanical rotation speed of the inner rotor 32 .
- the outer rotor 31 rotates under the action of the rotating magnetic field, thereby realizing the transmission of the moment of inertia.
- the frequency converter 40 supplies alternating current to the outer rotor 31, so that the outer rotor 31 generates a rotating magnetic field.
- the actual rotational speed of the rotating magnetic field generated by the outer rotor 31 is the ratio of the rotating magnetic field speed matched by the current supplied by the frequency converter 40 and the mechanical speed of the outer rotor 32. overlay. Because the rotating field speed of the outer rotor 31 is equal to the rotating field speed of the inner rotor 32 .
- the mechanical rotational speed of the outer rotor 31 drives the generator 50 to input current with a stable frequency to the grid.
- the electromagnetic coupler 30 has the function of variable speed, and through the function of the electromagnetic coupler 30 , the generator 50 can input constant frequency current to the power grid.
- the stable input of electric energy by the generator 50 to the grid is not affected by changes in the rotational speed of the flywheel rotor 20 , even if the rotational speed of the flywheel rotor 20 changes, the generator 50 can stably input electric energy to the grid.
- the rotational speed of the outer rotor 31 is 3000 rpm, and the generator 50 can stably input current with a frequency of 50 Hz to the grid.
- the flywheel energy storage system 1 can be connected to the grid to participate in the grid inertia response, store the overflow energy in the flywheel rotor 20 according to the overflow ratio, or draw energy from the flywheel rotor 20 according to the missing ratio to supplement the grid, reducing grid frequency fluctuations.
- the flywheel rotor of the flywheel energy storage system is connected to the electromagnetic coupler with variable speed function, and the output speed of the electromagnetic coupler can remain unchanged, so it can drive the generator to generate constant frequency current to meet the requirements of power transmission to the grid Require. Since the electromagnetic coupler has a variable speed function, the change in the rotational speed of the flywheel rotor will not affect the input of constant frequency current from the generator to the grid.
- the flywheel energy storage system provided by the embodiment of the present disclosure is connected to the grid without using power electronic devices for decoupling, Rectification, frequency modulation, and voltage stabilization solve the problem that the total moment of inertia caused by the use of power electronic devices in the current power grid is continuously reduced, and can increase the moment of inertia in the power grid, provide the necessary voltage and frequency support for the power grid, and reduce the The risk of large frequency deviations in the power grid enables the power system to operate safely and stably, and improves the ability of the grid to efficiently accept new energy.
- a flywheel energy storage system 1 includes a motor 10 , a flywheel rotor 20 , an electromagnetic coupler 30 , a frequency converter 40 , a generator 50 and a transmission shaft.
- the electric motor 10 is connected with the flywheel rotor 20, and the electric motor 10 can drive the speed of the flywheel rotor 20 to increase through the transmission shaft to store kinetic energy.
- the flywheel rotor 20 can drive the outer rotor 31 of the electromagnetic coupler 30 to rotate through the transmission shaft.
- the outer rotor 31 generates a rotating magnetic field to drive the inner rotor 32 to rotate at a constant speed.
- the inner rotor 32 rotates to drive the generator 50 to generate electricity.
- the generator 50 is connected to the grid through a transformer (not shown in the figure) to supply power to the grid. In this embodiment, the generator 50 is a synchronous generator.
- the mechanical speed of the outer rotor 31 is equal to the output speed of the flywheel rotor 20
- the mechanical speed of the inner rotor 32 is equal to the input speed of the generator 50 .
- the mechanical rotational speed of the inner rotor 32 was constant at 3000 rpm.
- the output frequency of the generator 50 is stabilized at 50 Hz.
- the domestic power grid frequency reference line is 50 Hz
- the rotational speed of the inner rotor 32 can be kept constant at 3000 rpm.
- the grid frequency reference line abroad is 60 Hz, and the speed of the inner rotor 32 can be kept constant at 3600 rpm, that is, the rated speed of the inner rotor 32 can be adjusted according to the grid frequency reference.
- the rotational speed of the flywheel rotor 20 is constantly changing, resulting in constant changes in the mechanical rotational speed of the outer rotor 31 . Therefore, if the rotational speed of the inner rotor 32 is to be kept constant, it can be achieved by changing the current passed into the outer rotor 31 .
- the frequency of the current transmitted from the frequency converter 40 to the outer rotor 31 is changed to match the magnetic field of the outer rotor 31 current
- the rotational speed r2 is adjusted to finally make the rotational magnetic field rotational speed r0 of the outer rotor 31 equal to the ideal mechanical rotational speed of the inner rotor 32 .
- the magnetic field speed r2 for current matching of the outer rotor 31 is not a mechanical speed.
- a positive value of r2 means that the rotation direction of the rotating magnetic field matched by the current of the outer rotor 31 is the same as the mechanical rotation direction of the outer rotor 31 .
- a negative value of r2 means that the rotation direction of the rotating magnetic field matched by the current of the outer rotor 31 is opposite to the mechanical rotation direction of the outer rotor 31 .
- the mechanical speed generated by the rotation of the outer rotor 31 and the magnetic field speed generated by the current of the outer rotor 31 are superimposed to reach the ideal speed value of the inner rotor 32, so that the mechanical speed of the inner rotor 32 is not affected by the change of the speed of the flywheel rotor 20 and always maintained constant, so that the generator 50 can transmit power to the grid at a constant frequency to realize synchronous power generation.
- a preset value is set for it, and according to the current speed of the flywheel rotor 20, the frequency of the current input from the frequency converter 40 to the outer rotor 31 is adjusted, so that the outer rotor 31 The rotating speed of the magnetic field remains constant, and the generator 50 can generate electricity stably.
- the outer rotor 31 includes an outer rotor iron core and an outer rotor winding, and the frequency converter 40 is connected to the outer rotor winding.
- the inner rotor 32 includes an inner rotor core and an inner rotor winding.
- the flywheel energy storage system 1 has an energy storage state and an energy release state, and can switch between the energy storage state and the energy release state. It can also be said that the flywheel energy storage system 1 includes an energy storage stage and an energy release stage during operation, the energy storage stage corresponds to the above energy storage state, and the energy release stage corresponds to the above energy release state.
- the flywheel energy storage system 1 converts electrical energy into kinetic energy for storage; when the flywheel energy storage system 1 is in the energy release state, it releases its stored kinetic energy and converts the kinetic energy into electrical energy for output.
- the electric motor 10 operates to obtain electricity from the grid and drives the flywheel rotor 20 to rotate through the transmission shaft. That is to say, in the energy storage stage, no power transmission is performed between the generator 50 and the grid, and the generator 50 does not generate electricity.
- the flywheel rotor 20 is driven by the motor 10 to increase its speed to a rated maximum speed.
- the flywheel rotor 20 completes energy storage, and then the motor 10 stops driving the flywheel rotor 20 .
- the rated maximum rotational speed is 100rpm-1000000rpm.
- the flywheel rotor 20 drives the outer rotor 31 to rotate through the transmission shaft, the outer rotor 31 rotates to drive the inner rotor 32 to rotate, the inner rotor 32 drives the generator 50 to generate electricity, and the generator 50 is connected to the grid through a transformer.
- the flywheel rotor 20 releases kinetic energy and the rotational speed drops.
- the standby state of the motor 10 in the energy-discharging state means that the motor 10 is not operating, and it does not drive the flywheel rotor 20 to accelerate. That is to say, when the flywheel energy storage system 1 is in the energy release state, there is only energy output in the flywheel energy storage system 1 , but no energy input. When the flywheel energy storage system 1 is in the above energy storage state, there is only energy input in the flywheel energy storage system 1 and no energy output.
- the current frequency of the outer rotor 31 is changed according to the difference between the rotational speed of the flywheel rotor 20 (the mechanical rotational speed of the outer rotor 31) and the predetermined mechanical rotational speed of the inner rotor 32, so that the inner rotor 32 maintains a preset magnetic field Rotating at a high speed, the generator 50 produces a steady current.
- the electromagnetic moments of the outer rotor 31 and the inner rotor 32 can be adjusted to balance the electromagnetic moments of the outer rotor 31 and the inner rotor 32.
- the flywheel energy storage system 1 also has a standby state. It can also be said that the flywheel energy storage system 1 also includes a standby stage during operation. When the flywheel energy storage system 1 is in the standby state, the flywheel energy storage system 1 is in the energy maintenance stage, that is, there is no energy input or energy output, and the flywheel energy storage system 1 operates with minimum loss. In the standby state, the motor 10 is on standby, the generator 50 is idling, and the flywheel rotor 20 releases a small amount of kinetic energy to keep the outer rotor 31 rotating.
- the flywheel energy storage system 1 enters a standby state, and the flywheel rotor 20 loses a small amount of kinetic energy to maintain the rotation of the outer rotor 31, ensuring that the flywheel energy storage system 1 Optimum for the next grid frequency fluctuation.
- a preset value for example, the grid frequency is equal to 50Hz
- the flywheel energy storage system 1 when the flywheel energy storage system 1 is connected to the grid, it can perform inertia response or frequency regulation on the grid.
- the motor 10 absorbs the excess electric energy from the power grid to drive the flywheel rotor 20 to rotate at a higher speed, so that the electric energy is converted into kinetic energy and stored in the flywheel rotor 20, thereby reducing the frequency of the power grid.
- the flywheel rotor 20 drives the generator 50 to generate electricity, and the flywheel rotor 20 rotates at a lower speed, so that kinetic energy is converted into electrical energy and input to the grid, thereby increasing the frequency of the grid.
- the flywheel energy storage system 1 further includes a flywheel energy storage controller.
- the flywheel energy storage controller is used to control the energy input and input power of the flywheel energy storage unit 10, that is, the flywheel energy storage controller is used to control whether to input electric energy to the flywheel energy storage unit 10, and is also used to control the input power to the flywheel energy storage unit 10. power of electrical energy.
- the flywheel energy storage controller is powered by an independent power source to ensure that it will not be affected by fluctuations in the external power grid.
- the flywheel energy storage controller includes a grid detection module and a motor control module.
- the power grid detection module is used to detect the current frequency of the power grid.
- the power grid detection module can monitor the frequency of the power grid in real time, so as to better respond to and regulate the frequency of the power grid.
- the motor control module when the motor control module receives the current frequency signal of the power grid and judges that it is necessary to start the motor 10 to store energy in the flywheel energy storage unit 10, the motor control module sends a start signal to the motor 10 to start the motor 10, and from absorb electricity from the grid.
- the motor control module judges according to the current frequency of the power grid that there is no need to store energy in the flywheel energy storage unit 10 , it sends a shutdown signal to the motor 10 to shut down the motor 10 .
- the motor control module can also determine the magnitude of the input power of the motor 10 according to the current frequency of the grid, and control the power input to the motor 10 .
- the motor control module determines to change the input power of the motor 10 to adjust the frequency of the grid to suppress further increase of the grid frequency.
- the flywheel energy storage unit 10 can absorb more electric energy, and the rotation speed of the flywheel rotor 20 increases.
- the greater the frequency deviation of the grid the greater the moment of the flywheel rotor 20 , that is, the greater the input power of the motor 10 . It can be understood that the input power of the motor 10 will not exceed the maximum power it can withstand.
- the flywheel energy storage system 1 provided in the embodiment of the present application can realize auxiliary services such as power grid disturbance power distribution, inertia response, and primary frequency regulation, and improve the primary frequency regulation and inertia support capabilities of the power system. Compared with traditional mechanical inertia, the flywheel energy storage system 1 provided by the embodiment of the present application can provide faster and more stable frequency control.
- the flywheel energy storage system 1 further includes a speed change device, which is connected between the flywheel rotor 20 and the electromagnetic coupler 30, and the speed change device has The input end and the output end, the flywheel rotor 20 is drivingly connected with the input end of the transmission, the output end of the transmission is connected with the outer rotor 31 of the electromagnetic coupler 30, and the transmission is used for speed change.
- the variator also serves to transmit the moment of inertia of the flywheel rotor.
- the speed change device is used to adjust the speed of the flywheel rotor 20 input to the electromagnetic coupler 30, and the speed change ratio of the speed change device is the ratio of the input end (the speed of the flywheel rotor 20) to the output end (the speed of the outer rotor 31). .
- the output speed of the flywheel rotor 20 can be better adapted to the application range of the speed of the electromagnetic coupler 30, and the burden on the electromagnetic coupler 30 can be alleviated.
- the input rotational speed of the coupler 30 (the mechanical rotational speed of the outer rotor 31 ) is within an ideal range.
- the ideal range of the input speed of the electromagnetic coupler 30 is (3000 ⁇ 1000) rpm, when the input speed of the electromagnetic coupler 30 (the speed of the outer rotor 31) is within the range of (3000 ⁇ 1000) rpm, the electromagnetic coupler 30 It is possible to respond more quickly to changes in the rotation speed of the outer rotor 31 to keep the rotation speed of the magnetic field of the outer rotor 31 constant.
- the output rotational speed of the flywheel rotor 20 can be varied within the ideal range of the input rotational speed of the electromagnetic coupler 30 by providing a transmission device with an appropriate transmission ratio.
- the transmission device is a transmission device with a fixed transmission ratio (constant transmission ratio transmission device 61 ), or the transmission device is a transmission device with an adjustable transmission ratio (speed ratio adjustable device 62 ).
- the transmission device being a transmission device with an adjustable transmission ratio means that the transmission device may be a multi-stage transmission device or a continuously variable transmission device.
- the speed change device is a multi-stage speed change device, which has multiple speed change ratios, and its speed change ratio can be adjusted according to the rotating speed of the flywheel rotor 20.
- the speed change device is a step speed change device, and it can continuously adjust its speed change ratio within a certain range.
- the transmission ratio of the transmission device is 0.03-333.
- the transmission device is a gear transmission with a one-stage or multi-stage transmission function, a hydraulic torque converter, a magnetic transformer, a permanent magnet transmission or a magnetic coupling transmission device.
- FIGS. 1-4 Several specific embodiments of the present disclosure are described below according to FIGS. 1-4 .
- the flywheel energy storage system 1 of this embodiment includes a motor 10, a flywheel rotor 20, an electromagnetic coupler 30, a frequency converter 40, a generator 50, a first transmission shaft 71, and a second transmission shaft 72 .
- the electromagnetic coupler 30 includes an outer rotor 31 and an inner rotor 32 , the outer rotor 31 is the input end of the electromagnetic coupler 30 , and the inner rotor 32 is drivingly connected to the input end of the generator 50 .
- the motor 10 is located on the side of the flywheel rotor 20 away from the electromagnetic coupler 30, the first transmission shaft 71 passes through the flywheel rotor 20 and is connected with the flywheel rotor 20, and one end of the first transmission shaft 71 of the transmission shaft 30 is connected to the output end of the motor 10. The other end of the first transmission shaft 71 is connected with the outer rotor 31 .
- One end of the second transmission shaft 72 is in transmission connection with the inner rotor 32 , and the other end of the second transmission shaft 72 is in transmission connection with the input end of the generator 50 .
- the flywheel energy storage system 1 of this embodiment has an energy storage state, an energy release state and a standby state, that is, the working process of the flywheel energy storage system 1 has an energy storage stage, an energy release stage and a standby stage.
- the generator 50 is idling, and the electric motor 10 absorbs electric energy from the grid.
- the output end of the electric motor 10 drives the speed of the flywheel rotor 20 to rise through the first drive shaft 71, and the speed of the flywheel rotor 20 rises to store kinetic energy, that is, the electric energy is converted into Kinetic energy is stored in the flywheel rotor 20 .
- the rotational speed of the flywheel rotor 20 increases until it reaches the set rotational speed. It can be understood that in the energy storage stage, the flywheel energy storage system 1 only has energy input but no energy output.
- the motor 10 In the energy release stage, the motor 10 is on standby, that is, the motor 10 does not input energy to the flywheel rotor 20, and the flywheel rotor 20 releases kinetic energy.
- the flywheel rotor 20 drives the outer rotor 31 to rotate through the first transmission shaft 71, and the inner rotor 32 rotates and passes through the second drive shaft 71 to rotate.
- the shaft 72 drives the generator 50 to generate electricity, and the generator 50 inputs electric energy with a stable frequency to the power grid through the transformer, without using power electronic devices for decoupling, rectification, frequency modulation, and voltage stabilization, which improves the moment of inertia in the power grid and provides the necessary power for the power grid.
- the voltage and frequency support reduces the risk of large frequency deviations in the power grid, enables the power system to operate safely and stably, and improves the ability of the grid to efficiently accept new energy.
- the generator 50 is connected to the grid, and the frequency of its output current is 50 Hz.
- the rotational speed of the flywheel rotor 20 the mechanical rotational speed r1 of the outer rotor 31
- the ideal mechanical rotational speed of the inner rotor 32 the frequency of the current transmitted from the frequency converter 40 to the outer rotor 31 is changed, and the magnetic field for matching the current of the outer rotor 31 is adjusted.
- the rotation speed is to finally make the rotating field rotation speed r0 of the outer rotor 31 equal to the ideal mechanical rotation speed of the inner rotor 32 .
- the mechanical speed of the inner rotor 32 is always constant without being affected by the change of the speed of the flywheel rotor 20, so that the generator 50 can transmit power to the grid at a constant frequency to realize synchronous power generation.
- the motor 10 In the standby phase, the motor 10 is on standby and the generator 50 is idling.
- the flywheel rotor 20 loses a small amount of mechanical energy to maintain the system no-load consumption.
- the flywheel energy storage system 1 of this embodiment is described below by taking FIG.
- the transmission device 61 the first transmission shaft 71 , the second transmission shaft 72 and the third transmission shaft 73 .
- the flywheel rotor 20, the motor 10, and the electromagnetic coupler 30 are similar to those in the first embodiment, and will not be repeated here, only the differences will be described.
- the first transmission shaft 31 passes through the flywheel rotor 20 and is connected in transmission with the flywheel rotor 20 , one end of the first transmission shaft 31 is in transmission connection with the output end of the motor 10 , and the other end of the first transmission shaft 31 is connected to the fixed
- the input end of the variable speed ratio transmission device 61 is connected in transmission.
- One end of the second transmission shaft 32 is in transmission connection with the output end of the constant speed ratio transmission device 61 , and the other end is connected with the outer rotor 31 .
- One end of the third transmission shaft 73 is connected with the inner rotor 32 , and the other end is connected with the input section of the generator 50 .
- the gear ratio of the constant gear ratio transmission device 61 is fixed, which is the ratio of the rotational speed of the input end to the rotational speed of the output end.
- the rotational speed of the flywheel rotor 20 is equal to the rotational speed of the input end of the constant speed ratio transmission device 61
- the rotational speed of the output end of the constant speed ratio transmission device 61 is equal to the rotational speed of the outer rotor 31 .
- the stator of the generator is disconnected from the grid, the electromagnetic coupler 30 idles, the electric motor 10 absorbs electric energy from the grid, and the output end of the motor 10 drives the speed of the flywheel rotor 20 to rise through the first drive shaft 31, and the flywheel rotor 20
- the rising speed stores kinetic energy, that is, electric energy is converted into kinetic energy and stored in the flywheel rotor 20 .
- the rotational speed of the flywheel rotor 20 increases until it reaches the set rotational speed. It can be understood that in the energy storage stage, the flywheel energy storage system 1 only has energy input but no energy output.
- the motor 10 In the energy release stage, the motor 10 is on standby, that is, the motor 10 does not input energy to the flywheel rotor 20, and the flywheel rotor 20 releases kinetic energy, and the flywheel rotor 20 drives the input end of the constant speed ratio transmission device 61 to rotate through the first transmission shaft 31, and the moment of inertia changes from
- the output end of the constant speed ratio speed changer 61 is output, and the rotating speed of the output end of the constant speed change ratio speed changer 61 is related to the input end speed of the constant speed change ratio speed changer 61 and the speed ratio of the constant speed change ratio speed changer 61, the constant speed ratio speed changer
- the output end of 61 drives the outer rotor 31 to rotate through the second transmission shaft 32 , the rotation of the outer rotor 31 drives the rotation of the inner rotor 32 , and the inner rotor 32 drives the generator 50 to generate electricity through the third transmission shaft 72 .
- a fixed speed ratio transmission device 61 is set between the flywheel rotor 20 and the electromagnetic coupler 30, so that the rotating speed of the generator rotor can better adapt to the application range of the electromagnetic coupler 30, and reduce the burden on the electromagnetic coupler 30, that is, the speed change device can make the output speed of the flywheel rotor 20 change to the ideal range of the input speed of the electromagnetic coupler 30 (the mechanical speed of the outer rotor 31), so that the electromagnetic coupler 30 can better output stable current through rotor compensation.
- the ideal range of the input rotational speed of the electromagnetic coupler 30 is (3000 ⁇ 1000) rpm, and by setting a speed change device with a suitable gear ratio, the output rotational speed of the flywheel rotor 20 can be changed to 100% of the input rotational speed of the electromagnetic coupler 30. within this ideal range.
- the input rotational speed of the electromagnetic coupler 30 (the rotational speed of the generator rotor) is within the range of (3000 ⁇ 1000) rpm
- the electromagnetic coupler 30 can respond more quickly to the change of the mechanical rotational speed of the outer rotor 31 to maintain the rotational speed of the outer rotor 31
- the rotational speed of the magnetic field is constant.
- the transmission ratio of the constant transmission ratio transmission device 61 is 0.03-333.
- the constant speed ratio transmission device 61 is a gear transmission with a transmission function, a hydraulic torque converter, a magnetic transformer, a permanent magnet transmission or a magnetic coupling transmission device.
- the flywheel energy storage system 1 of this embodiment is described below by taking FIG. Adjusting device 62, first transmission shaft 71, second transmission shaft 72 and third transmission shaft 73.
- the flywheel rotor 20, the motor 10, and the electromagnetic coupler 30 are similar to those in the first embodiment, and will not be repeated here, only the differences will be described.
- the first transmission shaft 31 passes through the flywheel rotor 20 and is connected with the flywheel rotor 20.
- One end of the first transmission shaft 31 is connected to the output end of the motor 10, and the other end of the first transmission shaft 31 is connected to the transmission.
- the input end of the ratio adjustable device 62 is connected by transmission.
- One end of the second transmission shaft 32 is in transmission connection with the output end of the gear ratio adjustable device 62 , and the other end is connected with the outer rotor 31 .
- One end of the third transmission shaft 73 is connected with the inner rotor 32 , and the other end is connected with the input section of the generator 50 .
- the variable speed ratio of the variable speed ratio adjustable device 62 is adjustable, and the variable speed ratio of the variable speed ratio adjustable device 62 is the ratio of the rotational speed of the input end to the rotational speed of the output end.
- variable speed ratio device 62 can be a multi-stage speed change device, that is, the variable speed ratio device 62 has multiple speed ratios, and can be switched according to the speed of the flywheel rotor 20 .
- the variable speed ratio device 62 can be a continuously variable speed device, that is, the variable speed ratio device 62 can continuously adjust its speed ratio within a certain range.
- the gear ratio adjustable device 62 is a gear transmission with a multi-stage or continuously variable transmission function, a hydraulic torque converter, a magnetic transformer, a permanent magnet transmission or a magnetic coupling transmission device.
- the output speed of the flywheel rotor 20 can be Better transition to the ideal range of the input speed of the electromagnetic coupler 30 , further reduce the current regulation burden of the electromagnetic coupler 30 , improve the applicability of the electromagnetic coupler 30 , and expand the speed range of the flywheel rotor 20 .
- variable speed ratio adjustable device 62 When the speed of the flywheel rotor 20 rises, the speed ratio of the variable speed ratio adjustable device 62 can be increased; The output end of the adjustable device 62 is kept within the ideal range of the input rotational speed of the electromagnetic coupler 30, so that the electromagnetic coupler 30 responds quickly to adjust and output a constant frequency current to the grid.
- the flywheel energy storage system 1 includes a motor 10 , a flywheel rotor 20 , an electromagnetic coupler 30 , a frequency converter 40 , a generator 50 and a transmission shaft.
- the electric motor 10 is connected with the flywheel rotor 20, and the electric motor 10 can drive the speed of the flywheel rotor 20 to increase through the transmission shaft to store kinetic energy.
- the flywheel rotor 20 can drive the inner rotor 32 of the electromagnetic coupler 30 to rotate through the transmission shaft.
- the inner rotor 32 generates a rotating magnetic field to drive the outer rotor 31 to rotate at a constant speed.
- the outer rotor 31 rotates to drive the generator 50 to generate electricity.
- the generator 50 is connected to the grid through a transformer (not shown in the figure) to supply power to the grid. In this embodiment, the generator 50 is a synchronous generator.
- the mechanical speed of the inner rotor 32 is equal to the output speed of the flywheel rotor 20
- the mechanical speed of the outer rotor 31 is equal to the input speed of the generator 50 .
- the mechanical rotational speed of the outer rotor 31 is constant at 3000 rpm.
- the output frequency of the generator 50 is stabilized at 50 Hz.
- the domestic power grid frequency reference line is 50 Hz
- the rotational speed of the outer rotor 31 can be kept constant at 3000 rpm.
- the grid frequency reference line in foreign countries is 60Hz
- the rotation speed of the outer rotor 31 can be kept constant at 3600rpm, that is, the rated rotation speed of the outer rotor 31 can be adjusted according to the grid frequency reference.
- the rotational speed of the flywheel rotor 20 is constantly changing, resulting in a constant change in the mechanical rotational speed of the inner rotor 32 . Therefore, if the mechanical speed of the outer rotor 31 is to be kept constant, it can be achieved by changing the current passing through the outer rotor 31 .
- the frequency of the current transmitted from the frequency converter 40 to the outer rotor 31 is changed to match the magnetic field of the outer rotor 31 current
- the rotational speed r2 is adjusted to finally make the mechanical rotational speed r1 of the outer rotor 31 equal to the ideal mechanical rotational speed of the outer rotor 31 , ie keep constant.
- the magnetic field speed r2 for current matching of the outer rotor 31 is not a mechanical speed.
- a positive value of r2 means that the rotation direction of the rotating magnetic field matched by the current of the outer rotor 31 is the same as the mechanical rotation direction of the outer rotor 31 .
- a negative value of r2 means that the rotation direction of the rotating magnetic field matched by the current of the outer rotor 31 is opposite to the mechanical rotation direction of the outer rotor 31 .
- the mechanical speed of the outer rotor 31 is always kept constant without being affected by the change of the speed of the flywheel rotor 20, so that the generator 50 can transmit power to the grid at a constant frequency to realize synchronous power generation.
- a preset value is set for it, and according to the current speed of the flywheel rotor 20, the frequency of the current input from the frequency converter 40 to the outer rotor 31 is adjusted, so that the outer rotor 31
- the mechanical rotational speed of the motor is kept constant, and the generator 50 can generate electricity stably.
- the outer rotor 31 includes an outer rotor iron core and an outer rotor winding
- the frequency converter 40 is connected to the outer rotor winding
- the inner rotor 32 includes an inner rotor core and an inner rotor winding.
- the flywheel energy storage system 1 has an energy storage state and an energy release state, and can switch between the energy storage state and the energy release state. It can also be said that the flywheel energy storage system 1 includes an energy storage stage and an energy release stage during operation, the energy storage stage corresponds to the above energy storage state, and the energy release stage corresponds to the above energy release state.
- the flywheel energy storage system 1 converts electrical energy into kinetic energy for storage; when the flywheel energy storage system 1 is in the energy release state, it releases its stored kinetic energy and converts the kinetic energy into electrical energy for output.
- the electric motor 10 operates to obtain electricity from the grid and drives the flywheel rotor 20 to rotate through the transmission shaft. That is to say, in the energy storage stage, no power transmission is performed between the generator 50 and the grid, and the generator 50 does not generate electricity.
- the flywheel rotor 20 is driven by the motor 10 to increase its speed to a rated maximum speed.
- the flywheel rotor 20 completes energy storage, and then the motor 10 stops driving the flywheel rotor 20 .
- the rated maximum rotational speed is 100rpm-1000000rpm.
- the motor 10 In the released state, the motor 10 is on standby, the flywheel rotor 20 drives the inner rotor 32 to rotate through the transmission shaft, the inner rotor 32 rotates to drive the outer rotor 31 to rotate, the outer rotor 31 drives the generator 50 to generate electricity, and the generator 50 is connected to the power grid through a transformer.
- the flywheel rotor 20 releases kinetic energy and the rotational speed drops.
- the standby state of the motor 10 in the energy-discharging state means that the motor 10 is not operating, and it does not drive the flywheel rotor 20 to accelerate. That is to say, when the flywheel energy storage system 1 is in the energy release state, there is only energy output in the flywheel energy storage system 1 , but no energy input. When the flywheel energy storage system 1 is in the above energy storage state, there is only energy input in the flywheel energy storage system 1 and no energy output.
- the current frequency of the outer rotor 31 is changed according to the difference between the rotational speed of the flywheel rotor 20 (the mechanical rotational speed of the inner rotor 32) and the predetermined mechanical rotational speed of the outer rotor 31, so that the outer rotor 31 maintains the preset mechanical speed.
- the generator 50 produces a steady current.
- the electromagnetic moments of the inner rotor 32 and the outer rotor 31 can be adjusted to balance the electromagnetic moments of the inner rotor 32 and the outer rotor 31.
- the flywheel energy storage system 1 also has a standby state. It can also be said that the flywheel energy storage system 1 also includes a standby stage during operation. When the flywheel energy storage system 1 is in the standby state, the flywheel energy storage system 1 is in the energy maintenance stage, that is, there is no energy input or energy output, and the flywheel energy storage system 1 operates with minimum loss. In the standby state, the motor 10 is on standby, the generator 50 is idling, and the flywheel rotor 20 releases a small amount of kinetic energy to keep the inner rotor 32 rotating.
- the flywheel energy storage system 1 enters a standby state, and the flywheel rotor 20 loses a small amount of kinetic energy to maintain the rotation of the inner rotor 32, ensuring that the flywheel energy storage system 1 is Optimum for the next grid frequency fluctuation.
- a preset value for example, the grid frequency is equal to 50 Hz
- the flywheel energy storage system 1 when the flywheel energy storage system 1 is connected to the grid, it can perform inertia response or frequency regulation on the grid.
- the motor 10 absorbs the excess electric energy from the power grid to drive the flywheel rotor 20 to rotate at a higher speed, so that the electric energy is converted into kinetic energy and stored in the flywheel rotor 20, thereby reducing the frequency of the power grid.
- the flywheel rotor 20 drives the generator 50 to generate electricity, and the flywheel rotor 20 rotates at a lower speed, so that kinetic energy is converted into electrical energy and input to the grid, thereby increasing the frequency of the grid.
- the flywheel energy storage system 1 further includes a flywheel energy storage controller.
- the flywheel energy storage controller is used to control the energy input and input power of the flywheel energy storage unit 10, that is, the flywheel energy storage controller is used to control whether to input electric energy to the flywheel energy storage unit 10, and is also used to control the input power to the flywheel energy storage unit 10. power of electrical energy.
- the flywheel energy storage controller is powered by an independent power source to ensure that it will not be affected by fluctuations in the external power grid.
- the flywheel energy storage controller includes a grid detection module and a motor control module.
- the power grid detection module is used to detect the current frequency of the power grid.
- the power grid detection module can monitor the frequency of the power grid in real time, so as to better respond to and regulate the frequency of the power grid.
- the motor control module when the motor control module receives the current frequency signal of the power grid and judges that it is necessary to start the motor 10 to store energy in the flywheel energy storage unit 10, the motor control module sends a start signal to the motor 10 to start the motor 10, and from absorb electricity from the grid.
- the motor control module judges according to the current frequency of the power grid that there is no need to store energy in the flywheel energy storage unit 10 , it sends a shutdown signal to the motor 10 to shut down the motor 10 .
- the motor control module can also determine the magnitude of the input power of the motor 10 according to the current frequency of the grid, and control the power input to the motor 10 .
- the motor control module determines to change the input power of the motor 10 to adjust the frequency of the grid to suppress further increase of the grid frequency.
- the flywheel energy storage unit 10 can absorb more electric energy, and the rotation speed of the flywheel rotor 20 increases.
- the greater the frequency deviation of the grid the greater the moment of the flywheel rotor 20 , that is, the greater the input power of the motor 10 . It can be understood that the input power of the motor 10 will not exceed the maximum power it can withstand.
- the flywheel energy storage system 1 provided in the embodiment of the present application can realize auxiliary services such as power grid disturbance power distribution, inertia response, and primary frequency regulation, and improve the primary frequency regulation and inertia support capabilities of the power system. Compared with traditional mechanical inertia, the flywheel energy storage system 1 provided by the embodiment of the present application can provide faster and more stable frequency control.
- the flywheel energy storage system 1 further includes a speed change device, which is connected between the flywheel rotor 20 and the electromagnetic coupler 30, and the speed change device has The input end and the output end, the flywheel rotor 20 is drivingly connected with the input end of the transmission device, the output end of the transmission device is drivingly connected with the inner rotor 32 of the electromagnetic coupler 30, and the transmission device is used for speed change.
- the variator also serves to transmit the moment of inertia of the flywheel rotor.
- the speed change device is used to adjust the speed of the flywheel rotor 20 input to the electromagnetic coupler 30, and the speed change ratio of the speed change device is the ratio of the input end (the speed of the flywheel rotor 20) to the output end (the speed of the inner rotor 32). .
- the output speed of the flywheel rotor 20 can be better adapted to the application range of the speed of the electromagnetic coupler 30, and the burden on the electromagnetic coupler 30 can be alleviated.
- the input rotation speed of the coupler 30 (the mechanical rotation speed of the inner rotor 32) is within an ideal range.
- the ideal range of the input speed of the electromagnetic coupler 30 is (3000 ⁇ 1000) rpm, when the input speed of the electromagnetic coupler 30 (the speed of the inner rotor 32) is within the range of (3000 ⁇ 1000) rpm, the electromagnetic coupler 30 It is possible to respond more quickly to changes in the rotational speed of the inner rotor 32 to keep the magnetic field rotational speed of the inner rotor 32 constant.
- the output rotational speed of the flywheel rotor 20 can be varied within the ideal range of the input rotational speed of the electromagnetic coupler 30 by providing a transmission device with an appropriate transmission ratio.
- the transmission device is a transmission device with a fixed transmission ratio (constant transmission ratio transmission device 61 ), or the transmission device is a transmission device with an adjustable transmission ratio (speed ratio adjustable device 62 ).
- the transmission device being a transmission device with an adjustable transmission ratio means that the transmission device may be a multi-stage transmission device or a continuously variable transmission device.
- the speed change device is a multi-stage speed change device, which has multiple speed change ratios, and its speed change ratio can be adjusted according to the rotating speed of the flywheel rotor 20.
- the speed change device is a step speed change device, and it can continuously adjust its speed change ratio within a certain range.
- the transmission ratio of the transmission device is 0.03-333.
- the transmission device is a gear transmission with a one-stage or multi-stage transmission function, a hydraulic torque converter, a magnetic transformer, a permanent magnet transmission or a magnetic coupling transmission device.
- FIGS. 5-8 Several specific embodiments of the present disclosure are described below according to FIGS. 5-8 .
- the flywheel energy storage system 1 of this embodiment includes a motor 10, a flywheel rotor 20, an electromagnetic coupler 30, a frequency converter 40, a generator 50, a first transmission shaft 71, and a second transmission shaft 72 .
- the electromagnetic coupler 30 includes an inner rotor 32 and an outer rotor 31 , the inner rotor 32 is the input end of the electromagnetic coupler 30 , and the outer rotor 31 is in driving connection with the input end of the generator 50 .
- the motor 10 is located on the side of the flywheel rotor 20 away from the electromagnetic coupler 30, the first transmission shaft 71 passes through the flywheel rotor 20 and is connected with the flywheel rotor 20, and one end of the first transmission shaft 71 of the transmission shaft 30 is connected to the output end of the motor 10. The other end of the first transmission shaft 71 is connected with the inner rotor 32 .
- One end of the second transmission shaft 72 is in transmission connection with the outer rotor 31 , and the other end of the second transmission shaft 72 is in transmission connection with the input end of the generator 50 .
- the flywheel energy storage system 1 of this embodiment has an energy storage state, an energy release state and a standby state, that is, the working process of the flywheel energy storage system 1 has an energy storage stage, an energy release stage and a standby stage.
- the generator 50 is idling, and the electric motor 10 absorbs electric energy from the grid.
- the output end of the electric motor 10 drives the speed of the flywheel rotor 20 to rise through the first drive shaft 71, and the speed of the flywheel rotor 20 rises to store kinetic energy, that is, the electric energy is converted into Kinetic energy is stored in the flywheel rotor 20 .
- the rotational speed of the flywheel rotor 20 increases until it reaches the set rotational speed. It can be understood that in the energy storage stage, the flywheel energy storage system 1 only has energy input but no energy output.
- the motor 10 In the energy release stage, the motor 10 is on standby, that is, the motor 10 does not input energy to the flywheel rotor 20, and the flywheel rotor 20 releases kinetic energy.
- the flywheel rotor 20 drives the inner rotor 32 to rotate through the first transmission shaft 71, and the outer rotor 31 rotates and passes through the second transmission shaft.
- the shaft 72 drives the generator 50 to generate electricity, and the generator 50 inputs electric energy with a stable frequency to the power grid through the transformer, without using power electronic devices for decoupling, rectification, frequency modulation, and voltage stabilization, which improves the moment of inertia in the power grid and provides the necessary power for the power grid.
- the voltage and frequency support reduces the risk of large frequency deviations in the power grid, enables the power system to operate safely and stably, and improves the ability of the grid to efficiently accept new energy.
- the generator 50 is connected to the grid, and the frequency of its output current is 50 Hz.
- the frequency of the current transmitted from the frequency converter 40 to the outer rotor 31 is changed, and the magnetic field speed of the outer rotor 31 current matching is adjusted.
- the mechanical speed r1 of the outer rotor 31 equal to the ideal mechanical speed of the outer rotor 31 .
- the motor 10 In the standby phase, the motor 10 is on standby and the generator 50 is idling.
- the flywheel rotor 20 loses a small amount of mechanical energy to maintain the system no-load consumption.
- the flywheel energy storage system 1 of this embodiment is described below by taking FIG.
- the transmission device 61 the first transmission shaft 71 , the second transmission shaft 72 and the third transmission shaft 73 .
- the flywheel rotor 20, the motor 10, and the electromagnetic coupler 30 are similar to those in the first embodiment, and will not be repeated here, only the differences will be described.
- the first transmission shaft 31 passes through the flywheel rotor 20 and is connected in transmission with the flywheel rotor 20, one end of the first transmission shaft 31 is in transmission connection with the output end of the motor 10, and the other end of the first transmission shaft 31 is connected
- the input end of the variable speed ratio transmission device 61 is connected in transmission.
- One end of the second transmission shaft 32 is in drive connection with the output end of the constant speed ratio transmission device 61 , and the other end is connected with the inner rotor 32 .
- One end of the third transmission shaft 73 is connected with the outer rotor 31 , and the other end is connected with the input section of the generator 50 .
- the gear ratio of the constant gear ratio transmission device 61 is fixed, which is the ratio of the rotational speed of the input end to the rotational speed of the output end.
- the rotational speed of the flywheel rotor 20 is equal to the rotational speed of the input end of the constant speed ratio transmission device 61
- the rotational speed of the output end of the constant speed ratio transmission device 61 is equal to the rotational speed of the inner rotor 32 .
- the stator of the generator is disconnected from the grid, the electromagnetic coupler 30 idles, the electric motor 10 absorbs electric energy from the grid, and the output end of the motor 10 drives the speed of the flywheel rotor 20 to rise through the first drive shaft 31, and the flywheel rotor 20
- the rising speed stores kinetic energy, that is, electric energy is converted into kinetic energy and stored in the flywheel rotor 20 .
- the rotational speed of the flywheel rotor 20 increases until it reaches the set rotational speed. It can be understood that in the energy storage stage, the flywheel energy storage system 1 only has energy input but no energy output.
- the motor 10 In the energy release stage, the motor 10 is on standby, that is, the motor 10 does not input energy to the flywheel rotor 20, and the flywheel rotor 20 releases kinetic energy, and the flywheel rotor 20 drives the input end of the constant speed ratio transmission device 61 to rotate through the first transmission shaft 31, and the moment of inertia changes from
- the output end of the constant speed ratio speed changer 61 is output, and the rotating speed of the output end of the constant speed change ratio speed changer 61 is related to the input end speed of the constant speed change ratio speed changer 61 and the speed ratio of the constant speed change ratio speed changer 61, the constant speed ratio speed changer
- the output end of 61 drives the inner rotor 32 to rotate through the second transmission shaft 32 , the rotation of the inner rotor 32 drives the rotation of the outer rotor 31 , and the outer rotor 31 drives the generator 50 to generate electricity through the third transmission shaft 72 .
- a fixed speed ratio transmission device 61 is set between the flywheel rotor 20 and the electromagnetic coupler 30, so that the rotating speed of the generator rotor can better adapt to the application range of the electromagnetic coupler 30, and reduce the burden on the electromagnetic coupler 30, that is, the speed change device can make the output speed of the flywheel rotor 20 change to the ideal range of the input speed of the electromagnetic coupler 30 (the mechanical speed of the inner rotor 32), so that the electromagnetic coupler 30 can better output stable current through rotor compensation.
- the ideal range of the input rotational speed of the electromagnetic coupler 30 is (3000 ⁇ 1000) rpm, and by setting a speed change device with a suitable gear ratio, the output rotational speed of the flywheel rotor 20 can be changed to 100% of the input rotational speed of the electromagnetic coupler 30. within this ideal range.
- the input rotational speed of the electromagnetic coupler 30 (the rotational speed of the generator rotor) is in the range of (3000 ⁇ 1000) rpm
- the electromagnetic coupler 30 can respond more quickly to the change of the mechanical rotational speed of the inner rotor 32 to keep the outer rotor 31
- the mechanical speed is constant.
- the transmission ratio of the constant transmission ratio transmission device 61 is 0.03-333.
- the constant speed ratio transmission device 61 is a gear transmission with a transmission function, a hydraulic torque converter, a magnetic transformer, a permanent magnet transmission or a magnetic coupling transmission device.
- the flywheel energy storage system 1 of this embodiment is described below by taking FIG. Adjusting device 62, first transmission shaft 71, second transmission shaft 72 and third transmission shaft 73.
- the flywheel rotor 20, the motor 10, and the electromagnetic coupler 30 are similar to those in the first embodiment, and will not be repeated here, only the differences will be described.
- the first transmission shaft 31 passes through the flywheel rotor 20 and is connected in transmission with the flywheel rotor 20.
- One end of the first transmission shaft 31 is in transmission connection with the output end of the motor 10, and the other end of the first transmission shaft 31 is connected to the transmission.
- the input end of the ratio adjustable device 62 is connected by transmission.
- One end of the second transmission shaft 32 is in driving connection with the output end of the gear ratio adjustable device 62 , and the other end is connected with the inner rotor 32 .
- One end of the third transmission shaft 73 is connected with the outer rotor 31 , and the other end is connected with the input section of the generator 50 .
- the variable speed ratio of the variable speed ratio adjustable device 62 is adjustable, and the variable speed ratio of the variable speed ratio adjustable device 62 is the ratio of the rotational speed of the input end to the rotational speed of the output end.
- variable speed ratio device 62 can be a multi-stage speed change device, that is, the variable speed ratio device 62 has multiple speed ratios, and can be switched according to the speed of the flywheel rotor 20 .
- the variable speed ratio device 62 can be a continuously variable speed device, that is, the variable speed ratio device 62 can continuously adjust its speed ratio within a certain range.
- the gear ratio adjustable device 62 is a gear transmission with a multi-stage or continuously variable transmission function, a hydraulic torque converter, a magnetic transformer, a permanent magnet transmission or a magnetic coupling transmission device.
- the output speed of the flywheel rotor 20 can be Better transition to the ideal range of the input speed of the electromagnetic coupler 30 , further reduce the current regulation burden of the electromagnetic coupler 30 , improve the applicability of the electromagnetic coupler 30 , and expand the speed range of the flywheel rotor 20 .
- variable speed ratio adjustable device 62 When the speed of the flywheel rotor 20 rises, the speed ratio of the variable speed ratio adjustable device 62 can be increased; The output end of the adjustable device 62 is kept within the ideal range of the input rotational speed of the electromagnetic coupler 30, so that the electromagnetic coupler 30 responds quickly to adjust and output a constant frequency current to the grid.
- first and second are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features.
- the features defined as “first” and “second” may explicitly or implicitly include at least one of these features.
- “plurality” means at least two, such as two, three, etc., unless otherwise specifically defined.
- a first feature being “on” or “under” a second feature may mean that the first and second features are in direct contact, or that the first and second features are indirect through an intermediary. touch.
- “above”, “above” and “above” the first feature on 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.
- “Below”, “beneath” and “beneath” the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.
- the terms “one embodiment,” “some embodiments,” “example,” “specific examples,” or “some examples” mean a specific feature, structure, material, or feature described in connection with the embodiment or example. Features are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.
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Abstract
本公开提供了一种具有电磁耦合器的飞轮储能***,包括电动机、飞轮转子、电磁耦合器、变频器和发电机,电动机与飞轮转子相连以驱动飞轮转子旋转,电磁耦合器包括外转子和内转子,外转子套设内转子并与内转子之间间隔,飞轮转子与外转子或内转子传动连接,外转子产生旋转磁场带动内转子转动,或者,内转子产生旋转磁场带动外转子转动,电磁耦合器的输出转速能够保持不变,因此能够驱动发电机产生恒频电流,满足向电网输电的要求,无需采用电力电子装置,能够提高电网中的转动惯量,为电网提供必要的电压和频率支撑,提高了电网高效接纳新能源的能力。
Description
相关申请的交叉引用
本申请基于申请号为202111356233.1、申请日为2021年11月16日的中国专利申请,以及申请号为202111357475.2、申请日为2021年11月16日的中国专利申请提出,并要求该中国专利申请的优先权,该中国专利申请的全部内容在此引入本文作为参考。
本公开涉及储能技术领域,尤其是涉及一种具有电磁耦合器的飞轮储能***。
随着以清洁能源为主的新一轮能源变革的发展,新能源在我国电网中的占比将越来越高。但是,新能源技术中多采用电力电子装置接入电网,而电力电子装置没有转动惯量,无法主动为电网提供必要的电压和频率支撑,也无法提供必要的阻尼作用。尤其是随着通过电力电子装置连接到电网的分布式能源的渗透率越来越高,电网总的转动惯量不断减小,因此当发生重大的负荷或电源突变时电网出现大的频率偏差的风险也不断提高。高比例电力电子装置的接入会导致电网长期处于低惯量水平中,增加***不平衡功率冲击,这给电力***安全稳定的运行带来了越来越大的压力。为改善缓解电网运行压力及新能源消纳压力,亟需具备一定的支撑电网动态调整能力的储能***来提高电网高效接纳新能源的能力。
发明内容
本公开是基于发明人对以下事实和问题的发现和认识做出的:
飞轮储能技术是一种以动能形式存储能量的储能技术,通过电动机/发电机带动转子加速/减速的方式来实现能量的存储/释放。飞轮储能的主要优点是具有快速的爬坡能力、能量转换效率高和使用寿命长等,在提供辅助服务,例如惯量和频率调节等方面具有得天独厚的优势。且飞轮没有任何地理限制,可以轻松安装,具有可推广及可大规模复制的优点。
目前已有的飞轮储能技术均通过电力电子装置辅助电动/发电机进行动能和电能之间的相互转换过程。当***需要储存电能时,其会将外部输送来的交流电通过AC/DC的方式供给电动机,进而驱动飞轮转子旋转储能;当需要放电时,电力电子装置对飞轮转子的转子转动惯量进行解耦,起到整流、调频、稳压的作用,以满足负载用电需求。但是电力电子装置没有转动惯量,难以参与电网惯量响应,因此,飞轮储能技术无法解决当前电网中由电力电子装置的大规模使用导致的总的转动惯量比例不断减小的问题。
本公开旨在至少在一定程度上解决相关技术中的技术问题之一。为此,本公开提出一种具有电磁耦合器的飞轮储能***。
根据本公开的具有电磁耦合器的飞轮储能***,包括电动机、飞轮转子、电磁耦合器、变频器和发电机,所述电动机与所述飞轮转子相连以驱动所述飞轮转子旋转,所述电磁耦合器包括外转子和内转子,所述外转子套设所述内转子并与所述内转子之间间隔;所述飞轮转子与所述外转子传动连接,所述外转子产生旋转磁场带动所述内转子转动,所述变频器与所述外转子相连用于使所述旋转磁场的转速保持恒定,从而使所述内转子的转速保持恒定,所述内转子与所述发电机的输入端相连,所述发电机发电接入电网并向电网中输入具有稳定频率的电能;或者,所述飞轮转子与所述内转子传动连接,所述内转子产生旋转磁场带动所述外转子转动,所述变频器与所述外转子相连用于改变所述外转子的电流频率从而改变电流匹配的磁场转速,以便所述外转子的机械转速保持恒定,所述外转子与所述发电机的输入端相连,所述发电机发电接入电网并向电网中输入具有稳定频率的电能。
根据本公开实施例提供的飞轮储能***的飞轮转子与具有变速功能的电磁耦合器相连,电磁耦合器的输出转速能够保持不变,因此能够驱动发电机产生恒频电流,满足向电网输电的要求。由于电磁耦合器具有变速功能,飞轮转子的转速变化不会影响发电机向电网中输入恒频电流,因此将本公开实施例提 供的飞轮储能***与电网连接,无需采用电力电子装置解耦、整流、调频、稳压,解决了目前电网中由电力电子装置的使用导致的总的转动惯量不断减小的问题,能够提高电网中的转动惯量,为电网提供必要的电压和频率支撑,降低了电网出现大的频率偏差的风险,使电力***能够安全稳定的运行,并提高了电网高效接纳新能源的能力。
在一些实施例中,所述内转子包括内转子铁芯和内转子绕组,所述外转子包括外转子铁芯和外转子绕组,所述变频器与所述外转子绕组相连。
在一些实施例中,所述发电机为同步发电机。
在一些实施例中,所述电动机与电网相连并用于从电网取电,所述飞轮储能***具备释能状态和储能状态,
在所述释能状态下,所述电动机待机,所述飞轮转子释放动能驱动所述发电机发电,所述发电机向电网中输入具有稳定频率的电能,
在所述储能状态下,所述电动机从电网取电以驱动所述飞轮转子旋转,所述发电机空转。
在一些实施例中,所述飞轮储能***具备待机状态,在所述待机状态下,所述电动机待机,所述发电机空转。
在一些实施例中,飞轮储能***还包括变速装置,所述飞轮转子与所述变速装置的输入端传动连接,所述变速装置的输出端与所述外转子或所述内转子传动连接,所述变速装置用于传导所述飞轮转子的转动惯量。
在一些实施例中,所述变速装置为具有固定变速比的变速装置,或者,所述变速装置为变速比可调的变速装置。
在一些实施例中,所述变速装置为齿轮变速器、液力变矩器、磁力变液器或永磁变速器。
在一些实施例中,所述飞轮转子的转速为100rpm-1000000rpm,所述变速装置的变速比为0.03-333。
本公开的附加方面和优点将在下面的描述中部分给出,部分将从下面的描述中变得明显,或通过本公开的实践了解到。
图1是根据本公开实施例一的飞轮储能***的示意图。
图2是图1的局部示意图。
图3是根据本公开实施例二的飞轮储能***的示意图。
图4是根据本公开实施例三的飞轮储能***的示意图。
图5是根据本公开实施例四的飞轮储能***的示意图。
图6是图5的局部示意图。
图7是根据本公开实施例五的飞轮储能***的示意图。
图8是根据本公开实施例六的飞轮储能***的示意图。
图9是根据本公开实施例的飞轮储能控制器的示意图。
附图标记:
飞轮储能***1、电动机10、飞轮转子20、电磁耦合器30、外转子31、内转子32、变频器40、发电机50、定变速比变速装置61、变速比可调装置62、第一传动轴71、第二传动轴72、第三传动轴73。
下面详细描述本公开的实施例,所述实施例的示例在附图中示出。下面通过参考附图描述的实施例是示例性的,旨在用于解释本公开,而不能理解为对本公开的限制。
下面根据图1-图8描述本公开的实施例的飞轮储能***1的基本结构。如图1所示,飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40和发电机50。
飞轮转子20的加速能够实现能量的储存,飞轮转子20的减速能够实现能量的释放。其中飞轮转子20与电动机10相连,电动机10用于驱动飞轮转子20旋转。电动机10通过驱动飞轮转子20加速旋转, 最终实现电能以动能的形式储存在飞轮储能单元10中。可选地,电动机10与电网相连用于从电网中取电,电动机10从电网中取电驱动飞轮转子20旋转,飞轮转子20的转速上升以储存动能。
电磁耦合器30包括外转子31和内转子32,外转子31套设内转子32,外转子31与内转子32之间间隔。
在一些实施例中,飞轮转子20与外转子31传动连接,外转子31产生旋转磁场带动内转子32转动,变频器40与外转子31相连以便使所述旋转磁场的转速保持恒定,从而使内转子32的转速能够保持恒定。内转子32与发电机50的输入端相连,由于内转子32的转速能够保持恒定,发电机50发电接入电网并向电网中输入具有稳定频率的电能。外转子31的机械转速与内转子32的机械转速之比可以看做电磁耦合器30的传动比,因此电磁耦合器30可以看做是一种变传动比的变速装置。当本公开实施例提供的飞轮储能***1发电时,飞轮转子20的转动能够带动外转子31旋转,并且变频器40能够向外转子31通入交流电。
当变频器40向外转子31输入交流电,能够使外转子31产生旋转磁场,此外由于外转子31旋转,外转子31实际产生的旋转磁场的转速为变频器40通入的电流匹配的旋转磁场转速与外转子31的机械转速的叠加,内转子32在旋转磁场的作用下转动,内转子32的转速等于外转子31的磁场转速,从而实现转动惯量的传递。
需要说明的是,根据外转子31的机械转速和内转子32的预设转速的差值,通过变频器40改变通向外转子31的电流,可以改变电流匹配的磁场转速,使外转子31的磁场转速恒定,从而使内转子32的转速保持恒定,内转子32驱动发电机50向电网输入具有稳定频率的电流。
也就是说,电磁耦合器30具有变速的作用,通过电磁耦合器30的作用,发电机50能够向电网输入恒频电流。发电机50向电网稳定输入电能不受飞轮转子20的转速的变化的影响,即使飞轮转子20转速发生改变,发电机50也能够向电网稳定输入电能。
可选地,内转子32的转速为3000rpm,发电机50能够稳定向电网中输入频率为50Hz的电流。
可选地,飞轮储能***1可以与电网相连以便参与电网惯量响应,将溢出的能量按溢出比例存于飞轮转子20或者从飞轮转子20按缺失比例汲取能量补充电网,降低电网频率波动。
在另一些实施例中,飞轮转子20与内转子32传动连接,飞轮转子20传动以驱动内转子32旋转,内转子32旋转产生旋转磁场带动外转子32转动。变频器40与外转子31相连,变频器40用于改变通入外转子31的电流频率,从而改变通入外转子31的电流匹配的磁场转速,以便外转子31的机械转速能够保持恒定。外转子31与发电机50的输入端相连,由于外转子31的机械转速能够保持恒定,发电机50发电接入电网并向电网中输入具有稳定频率的电能。内转子32的机械转速与外转子31的机械转速之比可以看做电磁耦合器30的传动比,因此电磁耦合器30可以看做是一种变传动比的变速装置。
当本公开实施例提供的飞轮储能***1发电时,飞轮转子20的转动能够带动内转子32旋转。内转子32旋转产生旋转磁场,内转子32旋转磁场的转速等于内转子32的机械转速。外转子31在旋转磁场的作用下转动,从而实现了转动惯量的传递。
变频器40向外转子31通入交流电,使外转子31产生旋转磁场,外转子31实际产生的旋转磁场的转速为变频器40通入的电流匹配的旋转磁场转速与外转子32的机械转速的叠加。由于外转子31的旋转磁场转速等于内转子32的旋转磁场转速。根据内转子32的转速和外转子31的预设机械转速的差值,通过改变变频器40通入外转子31的电流频率,从而改变电流匹配的旋转磁场转速,能够实现外转子31的机械转速保持恒定,外转子31驱动发电机50向电网输入具有稳定频率的电流。
也就是说,电磁耦合器30具有变速的作用,通过电磁耦合器30的作用,发电机50能够向电网输入恒频电流。发电机50向电网稳定输入电能不受飞轮转子20的转速的变化的影响,即使飞轮转子20转速发生改变,发电机50也能够向电网稳定输入电能。
可选地,外转子31的转速为3000rpm,发电机50能够稳定向电网中输入频率为50Hz的电流。
可选地,飞轮储能***1可以与电网相连以便参与电网惯量响应,将溢出的能量按溢出比例存于飞轮转子20或者从飞轮转子20按缺失比例汲取能量补充电网,降低电网频率波动。
根据本公开实施例提供的飞轮储能***的飞轮转子与具有变速功能的电磁耦合器相连,电磁耦合器 的输出转速能够保持不变,因此能够驱动发电机产生恒频电流,满足向电网输电的要求。由于电磁耦合器具有变速功能,飞轮转子的转速变化不会影响发电机向电网中输入恒频电流,因此将本公开实施例提供的飞轮储能***与电网连接,无需采用电力电子装置解耦、整流、调频、稳压,解决了目前电网中由电力电子装置的使用导致的总的转动惯量不断减小的问题,能够提高电网中的转动惯量,为电网提供必要的电压和频率支撑,降低了电网出现大的频率偏差的风险,使电力***能够安全稳定的运行,并提高了电网高效接纳新能源的能力。
下面以图1所示的飞轮储能***1的示意图为例描述本公开实施例提供的一种飞轮储能***1的组成、连接关系及运作流程。
在图1所示的实施例中,飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50和传动轴。电动机10与飞轮转子20相连,电动机10能够通过传动轴驱动飞轮转子20的转速上升以储存动能。飞轮转子20能够通过传动轴驱动电磁耦合器30的外转子31转动。外转子31产生旋转磁场驱动内转子32恒速转速,内转子32转动驱动发电机50发电,发电机50通过变压器(图中未示出)与电网相连,向电网供电。在本实施例中,发电机50为同步发电机。
在本实施例中,外转子31的机械转速与飞轮转子20的输出转速相等,内转子32的机械转速与发电机50的输入转速相等。内转子32的机械转速恒定在3000rpm。发电机50的输出频率稳定在50Hz。
需要说明的是,国内的电网频率基准线为50Hz,内转子32的转速可以恒定在3000rpm。国外的电网频率基准线为60Hz,内转子32的转速可以恒定在3600rpm,即可以根据电网的频率基准,调整内转子32的额定转速。
本领域的技术人员可以理解的是,飞轮转子20的转速是在不断变化中的,导致外转子31的机械转速会断变化。因此,若要使内转子32的转速保持不变,可以通过改变通入外转子31的电流实现。
具体地,根据公式:外转子31的旋转磁场转速r0=外转子31的机械转速r1+外转子31电流匹配的磁场转速r2;外转子31的旋转磁场转速r0=内转子32的机械转速r3。根据飞轮转子20的转速(外转子31的机械转速r1)与内转子32的理想机械转速之间的差值,改变变频器40向外转子31传输的电流频率,使外转子31电流匹配的磁场转速r2调整,最终使外转子31的旋转磁场转速r0等于内转子32的理想机械转速。
若保持外转子31的磁场转速r0(电网转速)为3000rpm,则:
1)当飞轮转子20的转速小于3000rpm,外转子31电流匹配正的磁场转速,即r2为正值;
2)当飞轮转子20的转速等于3000rpm,外转子31电流匹配的磁场转速为零,即r2为0;
3)当飞轮转子20的转速大于3000rpm,外转子31电流匹配负的磁场转速,即r2为负值。
需要说明的是,外转子31电流匹配的磁场转速r2不是机械转速。r2为正值是指,外转子31电流匹配的旋转磁场的转动方向与外转子31的机械转动方向相同。r2为负值是指,外转子31电流匹配的旋转磁场的转动方向与外转子31的机械转动方向相反。通过外转子31旋转产生的机械转速与外转子31电流产生的磁场转速相叠加达到内转子32的理想转速值,实现内转子32的机械转速不受飞轮转子20的转速的变化的影响而始终保持恒定,使发电机50能够向电网恒频输电,实现同步发电。
也就是说,为了使内转子32的机械转速保持恒定,对其设定预设值,根据飞轮转子20当前的转速,调节变频器40向外转子31输入的电流频率,从而实现使外转子31的磁场转速保持恒定,发电机50能够稳定发电。
在本实施例中,外转子31包括外转子铁芯和外转子绕组,变频器40与外转子绕组相连。
可选地,内转子32包括内转子铁芯和内转子绕组。
进一步地,本申请实施例提供的飞轮储能***1具备储能状态和释能状态,且能够在储能状态和释能状态之间切换。也可以说,飞轮储能***1在运行过程包括储能阶段和释能阶段,储能阶段对应上述储能状态,释能阶段对应上述释能状态。当飞轮储能***1在储能状态下时,将电能转化为动能储存;当飞轮储能***1在释能状态下时,释放其储存的动能,并将动能转化为电能输出。
下面以电动机10与电网相连且可从电网中取电,发电机50能够向电网中输能为例描述本申请的技术方案,具体如下:
在储能状态下,电动机10运作从电网取电并通过传动轴驱动飞轮转子20转动,飞轮转子20的转速上升实现储能,且在该状态下发电机50空转以停止向电网中输入电能。也就是说,在储能阶段,发电机50与电网之间的不进行功率传递,发电机50不发电。
可选地,飞轮转子20在电动机10的驱动下转速上升到额定最高转速,当到达额定最高转速后,飞轮转子20完成储能,而后电动机10停止驱动飞轮转子20。可选地,额定最高转速为100rpm-1000000rpm。
在释能状态下,电动机10待机,飞轮转子20通过传动轴驱动外转子31转动,外转子31转动带动内转子32旋转,内转子32驱动发电机50发电,发电机50通过变压器连接电网。飞轮转子20释放动能转速下降。
其中在释能状态下电动机10待机是指,电动机10没有运作,其没有驱动飞轮转子20加速。也就是说,当飞轮储能***1处于释能状态下时,飞轮储能***1中只有能量输出,没有能量输入。当飞轮储能***1处于上述储能状态下时,飞轮储能***1中只有能量输入,没有能量输出。
需要说明的是,在释能状态下,根据飞轮转子20的转速(外转子31的机械转速)与内转子32的预定机械转速之差改变外转子31电流频率,使内转子32保持预设磁场转速转动,发电机50产生稳定电流。并且,还可以通过改变外转子31的电流频率、幅值,调节外转子31和内转子32的电磁力矩,使外转子31侧和内转子32侧的电磁力矩平衡。
在一些实施例中,飞轮储能***1还具备待机状态。也可以说,飞轮储能***1在运行过程还包括待机阶段。当飞轮储能***1在待机状态下时,飞轮储能***1处于能量保持阶段,即没有能量的输入也没有能量的输出,飞轮储能***1以最小的损耗运行。在待机状态下,电动机10待机,发电机50空转,飞轮转子20释放少量的动能以保持外转子31转动。
例如,当电网中的频率等于预设值时(例如电网频率等于50Hz),使飞轮储能***1进入待机状态,飞轮转子20损耗少量动能以维持外转子31转动,保证飞轮储能***1以最佳状态应对下一次电网频率波动。
在一些实施例中,飞轮储能***1接入电网能够对电网进行惯量响应或调频。当电网的频率上升时,电动机10从电网中吸取溢出的电能,驱动飞轮转子20转速上升,使电能转化为动能储存在飞轮转子20中,从而使得电网的频率降低。当电网的频率下降时,飞轮转子20驱动发电机50发电,飞轮转子20转速下降,使动能转化为电能输入电网,从而使得电网的频率提升。
在一些实施例中,如图9所示,飞轮储能***1还包括飞轮储能控制器。飞轮储能控制器用于控制飞轮储能单元10的能量输入及输入功率,即飞轮储能控制器用于控制是否向飞轮储能单元10中输入电能,还用于控制向飞轮储能单元10中输入的电能的功率。可选地,飞轮储能控制器由独立电源供电,以保证其不会受外界电网的波动影响。
飞轮储能控制器包括电网检测模块和电动机控制模块。电网检测模块用于检测电网的当前频率。可选地,电网检测模块能够对电网的频率进行实时监控,以便更好地对电网的频率进行响应、调控。
电动机控制模块与电网检测模块之间通讯连接,电网检测模块将检测到的电网的频率传递给电动机控制模块,电动机控制模块接收到频率信号,并根据频率信号控制电动机10的启闭,以及电动机10的输入功率。
也就是说,当电动机控制模块接收到电网的当前频率信号,并判断需要启动电动机10对飞轮储能单元10进行储能时,电动机控制模块向电动机10发送启动信号,使电动机10开启,并从电网中吸收电能。
当电动机控制模块根据电网的当前频率判断出,不需要向飞轮储能单元10储能时,向电动机10发动关闭信号,关闭电动机10。
并且,电动机控制模块还可以根据电网的当前频率判断出电动机10的输入功率的大小,并控制向电动机10输入的功率。
例如,当电网的当前频率上升至大于预设值时,电动机控制模块判断改变电动机10的输入功率以对电网进行调频,抑制电网频率的进一步抬升。通过改变电动机10的输入功率,能够使飞轮储能单元10吸收更多的电能,飞轮转子20的转速增加。并且电网的频率偏差越大,飞轮转子20的力矩越大, 即电动机10的输入功率越大。可以理解的是,电动机10的输入功率不会超过其能承受的最大功率。
因此,本申请实施例提供的飞轮储能***1能够实现对电网的扰动功率分配、惯量响应、一次调频等辅助服务,提高电力***一次调频及惯量支撑能力。相比于传统机械惯量,本申请实施例提供的飞轮储能***1能够提供更快速且更稳定的频率控制。
为了使发电机50更好地通过转子补偿输出稳定的电流,在一些实施例中,飞轮储能***1还包括变速装置,变速装置连接在飞轮转子20与电磁耦合器30之间,变速装置具有输入端和输出端,飞轮转子20与变速装置的输入端传动连接,变速装置的输出端与电磁耦合器30的外转子31传动连接,变速装置用于变速。变速装置还用于传导所述飞轮转子的转动惯量。
也就是说,变速装置用于对飞轮转子20输入电磁耦合器30的转速进行调速,变速装置的变速比为输入端(飞轮转子20的转速)与输出端(外转子31的转速)之比。通过变速装置变速,能够使飞轮转子20的输出转速更好地适应电磁耦合器30的转速适用范围,减轻电磁耦合器30的负担,即变速装置的设置可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速(外转子31的机械转速)的理想区间内。
例如,电磁耦合器30的输入转速的理想区间为(3000±1000)rpm,当电磁耦合器30的输入转速(外转子31的转速)在(3000±1000)rpm范围内时,电磁耦合器30能够对外转子31的转速变化进行更快速地响应,以保持外转子31的磁场转速恒定。通过设置具有合适变速比的变速装置,可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速的该理想区间内。
可选地,变速装置为具有固定变速比的变速装置(定变速比变速装置61),或者,变速装置为变速比可调的变速装置(变速比可调装置62)。变速装置为变速比可调的变速装置是指,变速装置可以为多级变速装置或无级变速装置。变速装置为多级变速装置,其具有多个变速比,且可根据飞轮转子20的转速情况调节其变速比,变速装置为级变速装置,其可在一定范围内连续调节其变速比。
可选地,变速装置的变速比为0.03-333。
可选地,变速装置为具有一级或多级变速功能的齿轮变速器、液力变矩器、磁力变液器、永磁变速器或磁耦合器变速装置。
下面根据图1-图4描述本公开的若干具体实施例。
实施例一:
如图1和图2所示,本实施例的飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50、第一传动轴71、第二传动轴72。电磁耦合器30包括外转子31和内转子32,外转子31为电磁耦合器30的输入端,内转子32与发电机50的输入端传动连接。
电动机10位于飞轮转子20的远离电磁耦合器30的一侧,第一传动轴71穿过飞轮转子20并与飞轮转子20传动连接,传动轴30第一传动轴71一端与电动机10的输出端传动连接,第一传动轴71的另一端与外转子31相连。第二传动轴72的一端与内转子32传动连接,第二传动轴72的另一端与发电机50的输入端传动连接。
本实施例的飞轮储能***1具有储能状态、释能状态和待机状态,即飞轮储能***1的工作过程具有储能阶段、释能阶段和待机阶段。
在储能阶段,发电机50空转,电动机10从电网中吸取电能,电动机10的输出端通过第一传动轴71驱动飞轮转子20的转速上升,飞轮转子20的转速上升储存动能,即电能转化为动能储存在飞轮转子20中。飞轮转子20的转速上升直至达到设定转速。可以理解的是,在储能阶段飞轮储能***1只有能量输入没有能量输出。
在释能阶段,电动机10待机,即电动机10不向飞轮转子20输入能量,飞轮转子20释放动能,飞轮转子20通过第一传动轴71驱动外转子31转动,内转子32转动并通过第二传动轴72驱动发电机50发电,发电机50通过变压器向电网中输入具有稳定频率的电能,无需采用电力电子装置解耦、整流、调频、稳压,提高了电网中的转动惯量,为电网提供必要的电压和频率支撑,降低了电网出现大的频率偏差的风险,使电力***能够安全稳定的运行,并提高了电网高效接纳新能源的能力。
作为示例,在释能阶段,发电机50并网,其输出电流的频率为50Hz。根据飞轮转子20的转速(外 转子31的机械转速r1)与内转子32的理想机械转速之间的差值,改变变频器40向外转子31传输的电流频率,调整外转子31电流匹配的磁场转速,最终使外转子31的旋转磁场转速r0等于内转子32的理想机械转速。实现内转子32的机械转速不受飞轮转子20的转速的变化的影响而始终保持恒定,使发电机50能够向电网恒频输电,实现同步发电。
在待机阶段,电动机10待机,发电机50空转。飞轮转子20损耗少量机械能维持***空载消耗。
实施例二:
下面以图3为例描述本实施例的飞轮储能***1,本实施例的飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50、定变速比变速装置61、第一传动轴71、第二传动轴72和第三传动轴73。飞轮转子20、电动机10、电磁耦合器30同实施例一类似,这里不作赘述,只描述区别部分。
如图3所示,第一传动轴31穿过飞轮转子20并与飞轮转子20传动连接,第一传动轴31的一端与电动机10的输出端传动连接,第一传动轴31的另一端与定变速比变速装置61的输入端传动连接。第二传动轴32的一端与定变速比变速装置61的输出端传动连接,另一端与外转子31相连。第三传动轴73一端与内转子32相连,另一端与发电机50的输入段相连。定变速比变速装置61的变速比固定,为输入端转速与输出端转速之比。
在本实施例中,飞轮转子20的转速等于定变速比变速装置61的输入端的转速,定变速比变速装置61的输出端的转速等于外转子31的转速。
在储能阶段,发电机定子与电网断开,电磁耦合器30空转,电动机10从电网中吸取电能,电动机10的输出端通过第一传动轴31驱动飞轮转子20的转速上升,飞轮转子20的转速上升储存动能,即电能转化为动能储存在飞轮转子20中。飞轮转子20的转速上升直至达到设定转速。可以理解的是,在储能阶段飞轮储能***1只有能量输入没有能量输出。
在释能阶段,电动机10待机,即电动机10不向飞轮转子20输入能量,飞轮转子20释放动能,飞轮转子20通过第一传动轴31驱动定变速比变速装置61的输入端旋转,转动惯量从定变速比变速装置61的输出端输出,且定变速比变速装置61的输出端的转速与定变速比变速装置61的输入端转速和定变速比变速装置61的变速比有关,定变速比变速装置61的输出端通过第二传动轴32带动外转子31转动,外转子31转动带动内转子32转动,内转子32通过第三传动轴72驱动发电机50发电。
在飞轮转子20与电磁耦合器30之间设置定变速比变速装置61,可以使发电机转子的转速更好地适应电磁耦合器30的转速适用范围,减轻电磁耦合器30的负担,即变速装置的设置可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速(外转子31的机械转速)的理想区间内,从而使电磁耦合器30更好地通过转子补偿输出稳定的电流。
可选地,电磁耦合器30的输入转速的理想区间为(3000±1000)rpm,通过设置具有合适变速比的变速装置,可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速的该理想区间内。当电磁耦合器30的输入转速(发电机转子的转速)在(3000±1000)rpm范围内时,电磁耦合器30能够对外转子31的机械转速变化进行更快速地响应,以保持外转子31的磁场转速恒定。
可选地,定变速比变速装置61的变速比为0.03-333。
可选地,定变速比变速装置61为具有变速功能的齿轮变速器、液力变矩器、磁力变液器、永磁变速器或磁耦合器变速装置。
实施例三:
下面以图4为例描述本实施例的飞轮储能***1,本实施例的飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50、变速比可调装置62、第一传动轴71、第二传动轴72和第三传动轴73。飞轮转子20、电动机10、电磁耦合器30同实施例一类似,这里不作赘述,只描述区别部分。
如图4所示,第一传动轴31穿过飞轮转子20并与飞轮转子20传动连接,第一传动轴31的一端与电动机10的输出端传动连接,第一传动轴31的另一端与变速比可调装置62的输入端传动连接。第二传动轴32的一端与变速比可调装置62的输出端传动连接,另一端与外转子31相连。第三传动轴73 一端与内转子32相连,另一端与发电机50的输入段相连。变速比可调装置62的变速比可调,变速比可调装置62的变速比为输入端转速与输出端转速之比。
可选地,变速比可调装置62可以为多级变速装置,即变速比可调装置62具有多个变速比,且可根据飞轮转子20的转速情况进行切换。或者,变速比可调装置62可以为无级变速装置,即变速比可调装置62可在一定范围内连续调节其变速比。
可选地,变速比可调装置62为具有多级或无级变速功能的齿轮变速器、液力变矩器、磁力变液器、永磁变速器或磁耦合器变速装置。
通过在飞轮转子20与电磁耦合器30之间设置变速比可调装置62,并根据飞轮转子20的当前转速适应性地调整变速比可调装置62的变速比,可以使飞轮转子20的输出转速更好地转变到电磁耦合器30的输入转速的理想区间内,进一步减轻电磁耦合器30的电流调节负担,提高电磁耦合器30的适用性,还可以扩大飞轮转子20的转速区间。
当飞轮转子20的转速上升时,可以使变速比可调装置62的变速比增大,当飞轮转子20的转速下降时,可以使变速比可调装置62的变速比减小,以使变速比可调装置62的输出端保持在电磁耦合器30的输入转速的理想区间内,使电磁耦合器30快速响应进行调节,向电网输出恒频电流。
下面以图5所示的飞轮储能***1的示意图为例描述本公开提供的另一种飞轮储能***1的组成、连接关系及运作流程。
在图5所示的实施例中,飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50和传动轴。电动机10与飞轮转子20相连,电动机10能够通过传动轴驱动飞轮转子20的转速上升以储存动能。飞轮转子20能够通过传动轴驱动电磁耦合器30的内转子32转动。内转子32产生旋转磁场驱动外转子31恒速转速,外转子31转动驱动发电机50发电,发电机50通过变压器(图中未示出)与电网相连,向电网供电。在本实施例中,发电机50为同步发电机。
在本实施例中,内转子32的机械转速与飞轮转子20的输出转速相等,外转子31的机械转速与发电机50的输入转速相等。外转子31的机械转速恒定在3000rpm。发电机50的输出频率稳定在50Hz。
需要说明的是,国内的电网频率基准线为50Hz,外转子31的转速可以恒定在3000rpm。国外的电网频率基准线为60Hz,外转子31的转速可以恒定在3600rpm,即可以根据电网的频率基准,调整外转子31的额定转速。
本领域的技术人员可以理解的是,飞轮转子20的转速是在不断变化中的,导致内转子32的机械转速会断变化。因此,若要使外转子31的机械转速保持不变,可以通过改变通入外转子31的电流实现。
具体地,根据公式:外转子31的旋转磁场转速r0=外转子31的机械转速r1+外转子31电流匹配的磁场转速r2;外转子31的旋转磁场转速r0=内转子32的机械/旋转磁场转速r3。根据飞轮转子20的转速(内转子32的机械转速r1)与外转子31的理想机械转速之间的差值,改变变频器40向外转子31传输的电流频率,使外转子31电流匹配的磁场转速r2调整,最终使外转子31的机械转速r1等于外转子31的理想机械转速,即保持恒定。
若保持外转子31的机械转速r1为3000rpm,则:
1)当飞轮转子20的转速小于3000rpm,外转子31电流匹配负的磁场转速,即r2为正值;
2)当飞轮转子20的转速等于3000rpm,外转子31电流匹配的磁场转速为零,即r2为0;
3)当飞轮转子20的转速大于3000rpm,外转子31电流匹配正的磁场转速,即r2为负值。
需要说明的是,外转子31电流匹配的磁场转速r2不是机械转速。r2为正值是指,外转子31电流匹配的旋转磁场的转动方向与外转子31的机械转动方向相同。r2为负值是指,外转子31电流匹配的旋转磁场的转动方向与外转子31的机械转动方向相反。外转子31的机械转速不受飞轮转子20的转速的变化的影响而始终保持恒定,使发电机50能够向电网恒频输电,实现同步发电。
也就是说,为了使外转子31的机械转速保持恒定,对其设定预设值,根据飞轮转子20当前的转速,调节变频器40向外转子31输入的电流频率,从而实现使外转子31的机械转速保持恒定,发电机50能够稳定发电。
在本实施例中,外转子31包括外转子铁芯和外转子绕组,变频器40与外转子绕组相连。内转子 32包括内转子铁芯和内转子绕组。
进一步地,本申请实施例提供的飞轮储能***1具备储能状态和释能状态,且能够在储能状态和释能状态之间切换。也可以说,飞轮储能***1在运行过程包括储能阶段和释能阶段,储能阶段对应上述储能状态,释能阶段对应上述释能状态。当飞轮储能***1在储能状态下时,将电能转化为动能储存;当飞轮储能***1在释能状态下时,释放其储存的动能,并将动能转化为电能输出。
下面以电动机10与电网相连且可从电网中取电,发电机50能够向电网中输能为例描述本申请的技术方案,具体如下:
在储能状态下,电动机10运作从电网取电并通过传动轴驱动飞轮转子20转动,飞轮转子20的转速上升实现储能,且在该状态下发电机50空转以停止向电网中输入电能。也就是说,在储能阶段,发电机50与电网之间的不进行功率传递,发电机50不发电。
可选地,飞轮转子20在电动机10的驱动下转速上升到额定最高转速,当到达额定最高转速后,飞轮转子20完成储能,而后电动机10停止驱动飞轮转子20。可选地,额定最高转速为100rpm-1000000rpm。
在释能状态下,电动机10待机,飞轮转子20通过传动轴驱动内转子32转动,内转子32转动带动外转子31旋转,外转子31驱动发电机50发电,发电机50通过变压器连接电网。飞轮转子20释放动能转速下降。
其中在释能状态下电动机10待机是指,电动机10没有运作,其没有驱动飞轮转子20加速。也就是说,当飞轮储能***1处于释能状态下时,飞轮储能***1中只有能量输出,没有能量输入。当飞轮储能***1处于上述储能状态下时,飞轮储能***1中只有能量输入,没有能量输出。
需要说明的是,在释能状态下,根据飞轮转子20的转速(内转子32的机械转速)与外转子31的预定机械转速之差改变外转子31电流频率,使外转子31保持预设机械转速转动,发电机50产生稳定电流。并且,还可以通过改变外转子31的电流频率、幅值,调节内转子32和外转子31的电磁力矩,使内转子32侧和外转子31侧的电磁力矩平衡。
在一些实施例中,飞轮储能***1还具备待机状态。也可以说,飞轮储能***1在运行过程还包括待机阶段。当飞轮储能***1在待机状态下时,飞轮储能***1处于能量保持阶段,即没有能量的输入也没有能量的输出,飞轮储能***1以最小的损耗运行。在待机状态下,电动机10待机,发电机50空转,飞轮转子20释放少量的动能以保持内转子32转动。
例如,当电网中的频率等于预设值时(例如电网频率等于50Hz),使飞轮储能***1进入待机状态,飞轮转子20损耗少量动能以维持内转子32转动,保证飞轮储能***1以最佳状态应对下一次电网频率波动。
在一些实施例中,飞轮储能***1接入电网能够对电网进行惯量响应或调频。当电网的频率上升时,电动机10从电网中吸取溢出的电能,驱动飞轮转子20转速上升,使电能转化为动能储存在飞轮转子20中,从而使得电网的频率降低。当电网的频率下降时,飞轮转子20驱动发电机50发电,飞轮转子20转速下降,使动能转化为电能输入电网,从而使得电网的频率提升。
在一些实施例中,如图9所示,飞轮储能***1还包括飞轮储能控制器。飞轮储能控制器用于控制飞轮储能单元10的能量输入及输入功率,即飞轮储能控制器用于控制是否向飞轮储能单元10中输入电能,还用于控制向飞轮储能单元10中输入的电能的功率。可选地,飞轮储能控制器由独立电源供电,以保证其不会受外界电网的波动影响。
飞轮储能控制器包括电网检测模块和电动机控制模块。电网检测模块用于检测电网的当前频率。可选地,电网检测模块能够对电网的频率进行实时监控,以便更好地对电网的频率进行响应、调控。
电动机控制模块与电网检测模块之间通讯连接,电网检测模块将检测到的电网的频率传递给电动机控制模块,电动机控制模块接收到频率信号,并根据频率信号控制电动机10的启闭,以及电动机10的输入功率。
也就是说,当电动机控制模块接收到电网的当前频率信号,并判断需要启动电动机10对飞轮储能单元10进行储能时,电动机控制模块向电动机10发送启动信号,使电动机10开启,并从电网中吸收电能。
当电动机控制模块根据电网的当前频率判断出,不需要向飞轮储能单元10储能时,向电动机10发动关闭信号,关闭电动机10。
并且,电动机控制模块还可以根据电网的当前频率判断出电动机10的输入功率的大小,并控制向电动机10输入的功率。
例如,当电网的当前频率上升至大于预设值时,电动机控制模块判断改变电动机10的输入功率以对电网进行调频,抑制电网频率的进一步抬升。通过改变电动机10的输入功率,能够使飞轮储能单元10吸收更多的电能,飞轮转子20的转速增加。并且电网的频率偏差越大,飞轮转子20的力矩越大,即电动机10的输入功率越大。可以理解的是,电动机10的输入功率不会超过其能承受的最大功率。
因此,本申请实施例提供的飞轮储能***1能够实现对电网的扰动功率分配、惯量响应、一次调频等辅助服务,提高电力***一次调频及惯量支撑能力。相比于传统机械惯量,本申请实施例提供的飞轮储能***1能够提供更快速且更稳定的频率控制。
为了使发电机50更好地通过转子补偿输出稳定的电流,在一些实施例中,飞轮储能***1还包括变速装置,变速装置连接在飞轮转子20与电磁耦合器30之间,变速装置具有输入端和输出端,飞轮转子20与变速装置的输入端传动连接,变速装置的输出端与电磁耦合器30的内转子32传动连接,变速装置用于变速。变速装置还用于传导所述飞轮转子的转动惯量。
也就是说,变速装置用于对飞轮转子20输入电磁耦合器30的转速进行调速,变速装置的变速比为输入端(飞轮转子20的转速)与输出端(内转子32的转速)之比。通过变速装置变速,能够使飞轮转子20的输出转速更好地适应电磁耦合器30的转速适用范围,减轻电磁耦合器30的负担,即变速装置的设置可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速(内转子32的机械转速)的理想区间内。
例如,电磁耦合器30的输入转速的理想区间为(3000±1000)rpm,当电磁耦合器30的输入转速(内转子32的转速)在(3000±1000)rpm范围内时,电磁耦合器30能够对内转子32的转速变化进行更快速地响应,以保持内转子32的磁场转速恒定。通过设置具有合适变速比的变速装置,可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速的该理想区间内。
可选地,变速装置为具有固定变速比的变速装置(定变速比变速装置61),或者,变速装置为变速比可调的变速装置(变速比可调装置62)。变速装置为变速比可调的变速装置是指,变速装置可以为多级变速装置或无级变速装置。变速装置为多级变速装置,其具有多个变速比,且可根据飞轮转子20的转速情况调节其变速比,变速装置为级变速装置,其可在一定范围内连续调节其变速比。
可选地,变速装置的变速比为0.03-333。
可选地,变速装置为具有一级或多级变速功能的齿轮变速器、液力变矩器、磁力变液器、永磁变速器或磁耦合器变速装置。
下面根据图5-图8描述本公开的若干具体实施例。
实施例四:
如图5和图6所示,本实施例的飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50、第一传动轴71、第二传动轴72。电磁耦合器30包括内转子32和外转子31,内转子32为电磁耦合器30的输入端,外转子31与发电机50的输入端传动连接。
电动机10位于飞轮转子20的远离电磁耦合器30的一侧,第一传动轴71穿过飞轮转子20并与飞轮转子20传动连接,传动轴30第一传动轴71一端与电动机10的输出端传动连接,第一传动轴71的另一端与内转子32相连。第二传动轴72的一端与外转子31传动连接,第二传动轴72的另一端与发电机50的输入端传动连接。
本实施例的飞轮储能***1具有储能状态、释能状态和待机状态,即飞轮储能***1的工作过程具有储能阶段、释能阶段和待机阶段。
在储能阶段,发电机50空转,电动机10从电网中吸取电能,电动机10的输出端通过第一传动轴71驱动飞轮转子20的转速上升,飞轮转子20的转速上升储存动能,即电能转化为动能储存在飞轮转子20中。飞轮转子20的转速上升直至达到设定转速。可以理解的是,在储能阶段飞轮储能***1只有 能量输入没有能量输出。
在释能阶段,电动机10待机,即电动机10不向飞轮转子20输入能量,飞轮转子20释放动能,飞轮转子20通过第一传动轴71驱动内转子32转动,外转子31转动并通过第二传动轴72驱动发电机50发电,发电机50通过变压器向电网中输入具有稳定频率的电能,无需采用电力电子装置解耦、整流、调频、稳压,提高了电网中的转动惯量,为电网提供必要的电压和频率支撑,降低了电网出现大的频率偏差的风险,使电力***能够安全稳定的运行,并提高了电网高效接纳新能源的能力。
作为示例,在释能阶段,发电机50并网,其输出电流的频率为50Hz。根据飞轮转子20的转速(内转子32的机械转速)与外转子31的理想机械转速之间的差值,改变变频器40向外转子31传输的电流频率,调整外转子31电流匹配的磁场转速,最终使外转子31的机械转速r1等于外转子31的理想机械转速。实现外转子31的机械转速不受飞轮转子20的转速的变化的影响而始终保持恒定,使发电机50能够向电网恒频输电,实现同步发电。
在待机阶段,电动机10待机,发电机50空转。飞轮转子20损耗少量机械能维持***空载消耗。
实施例五:
下面以图7为例描述本实施例的飞轮储能***1,本实施例的飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50、定变速比变速装置61、第一传动轴71、第二传动轴72和第三传动轴73。飞轮转子20、电动机10、电磁耦合器30同实施例一类似,这里不作赘述,只描述区别部分。
如图7所示,第一传动轴31穿过飞轮转子20并与飞轮转子20传动连接,第一传动轴31的一端与电动机10的输出端传动连接,第一传动轴31的另一端与定变速比变速装置61的输入端传动连接。第二传动轴32的一端与定变速比变速装置61的输出端传动连接,另一端与内转子32相连。第三传动轴73一端与外转子31相连,另一端与发电机50的输入段相连。定变速比变速装置61的变速比固定,为输入端转速与输出端转速之比。
在本实施例中,飞轮转子20的转速等于定变速比变速装置61的输入端的转速,定变速比变速装置61的输出端的转速等于内转子32的转速。
在储能阶段,发电机定子与电网断开,电磁耦合器30空转,电动机10从电网中吸取电能,电动机10的输出端通过第一传动轴31驱动飞轮转子20的转速上升,飞轮转子20的转速上升储存动能,即电能转化为动能储存在飞轮转子20中。飞轮转子20的转速上升直至达到设定转速。可以理解的是,在储能阶段飞轮储能***1只有能量输入没有能量输出。
在释能阶段,电动机10待机,即电动机10不向飞轮转子20输入能量,飞轮转子20释放动能,飞轮转子20通过第一传动轴31驱动定变速比变速装置61的输入端旋转,转动惯量从定变速比变速装置61的输出端输出,且定变速比变速装置61的输出端的转速与定变速比变速装置61的输入端转速和定变速比变速装置61的变速比有关,定变速比变速装置61的输出端通过第二传动轴32带动内转子32转动,内转子32转动带动外转子31转动,外转子31通过第三传动轴72驱动发电机50发电。
在飞轮转子20与电磁耦合器30之间设置定变速比变速装置61,可以使发电机转子的转速更好地适应电磁耦合器30的转速适用范围,减轻电磁耦合器30的负担,即变速装置的设置可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速(内转子32的机械转速)的理想区间内,从而使电磁耦合器30更好地通过转子补偿输出稳定的电流。
可选地,电磁耦合器30的输入转速的理想区间为(3000±1000)rpm,通过设置具有合适变速比的变速装置,可以使飞轮转子20的输出转速变化到电磁耦合器30的输入转速的该理想区间内。当电磁耦合器30的输入转速(发电机转子的转速)在(3000±1000)rpm范围内时,电磁耦合器30能够对内转子32的机械转速变化进行更快速地响应,以保持外转子31的机械转速恒定。
可选地,定变速比变速装置61的变速比为0.03-333。
可选地,定变速比变速装置61为具有变速功能的齿轮变速器、液力变矩器、磁力变液器、永磁变速器或磁耦合器变速装置。
实施例六:
下面以图8为例描述本实施例的飞轮储能***1,本实施例的飞轮储能***1包括电动机10、飞轮转子20、电磁耦合器30、变频器40、发电机50、变速比可调装置62、第一传动轴71、第二传动轴72和第三传动轴73。飞轮转子20、电动机10、电磁耦合器30同实施例一类似,这里不作赘述,只描述区别部分。
如图8所示,第一传动轴31穿过飞轮转子20并与飞轮转子20传动连接,第一传动轴31的一端与电动机10的输出端传动连接,第一传动轴31的另一端与变速比可调装置62的输入端传动连接。第二传动轴32的一端与变速比可调装置62的输出端传动连接,另一端与内转子32相连。第三传动轴73一端与外转子31相连,另一端与发电机50的输入段相连。变速比可调装置62的变速比可调,变速比可调装置62的变速比为输入端转速与输出端转速之比。
可选地,变速比可调装置62可以为多级变速装置,即变速比可调装置62具有多个变速比,且可根据飞轮转子20的转速情况进行切换。或者,变速比可调装置62可以为无级变速装置,即变速比可调装置62可在一定范围内连续调节其变速比。
可选地,变速比可调装置62为具有多级或无级变速功能的齿轮变速器、液力变矩器、磁力变液器、永磁变速器或磁耦合器变速装置。
通过在飞轮转子20与电磁耦合器30之间设置变速比可调装置62,并根据飞轮转子20的当前转速适应性地调整变速比可调装置62的变速比,可以使飞轮转子20的输出转速更好地转变到电磁耦合器30的输入转速的理想区间内,进一步减轻电磁耦合器30的电流调节负担,提高电磁耦合器30的适用性,还可以扩大飞轮转子20的转速区间。
当飞轮转子20的转速上升时,可以使变速比可调装置62的变速比增大,当飞轮转子20的转速下降时,可以使变速比可调装置62的变速比减小,以使变速比可调装置62的输出端保持在电磁耦合器30的输入转速的理想区间内,使电磁耦合器30快速响应进行调节,向电网输出恒频电流。
在本公开的描述中,需要理解的是,术语“中心”、“纵向”、“横向”、“长度”、“宽度”、“厚度”、“上”、“下”、“前”、“后”、“左”、“右”、“竖直”、“水平”、“顶”、“底”“内”、“外”、“顺时针”、“逆时针”、“轴向”、“径向”、“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系,仅是为了便于描述本公开和简化描述,而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作,因此不能理解为对本公开的限制。
此外,术语“第一”、“第二”仅用于描述目的,而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此,限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。在本公开的描述中,“多个”的含义是至少两个,例如两个,三个等,除非另有明确具体的限定。
在本公开中,除非另有明确的规定和限定,术语“安装”、“相连”、“连接”、“固定”等术语应做广义理解,例如,可以是固定连接,也可以是可拆卸连接,或成一体;可以是机械连接,也可以是电连接或彼此可通讯;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通或两个元件的相互作用关系,除非另有明确的限定。对于本领域的普通技术人员而言,可以根据具体情况理解上述术语在本公开中的具体含义。
在本公开中,除非另有明确的规定和限定,第一特征在第二特征“上”或“下”可以是第一和第二特征直接接触,或第一和第二特征通过中间媒介间接接触。而且,第一特征在第二特征“之上”、“上方”和“上面”可是第一特征在第二特征正上方或斜上方,或仅仅表示第一特征水平高度高于第二特征。第一特征在第二特征“之下”、“下方”和“下面”可以是第一特征在第二特征正下方或斜下方,或仅仅表示第一特征水平高度小于第二特征。
在本公开中,术语“一个实施例”、“一些实施例”、“示例”、“具体示例”、或“一些示例”等意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本公开的至少一个实施例或示例中。在本说明书中,对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且,描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外,在不相互矛盾的情况下,本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。
尽管上面已经示出和描述了本公开的实施例,可以理解的是,上述实施例是示例性的,不能理解为对本公开的限制,本领域的普通技术人员在本公开的范围内可以对上述实施例进行变化、修改、替换和变型。
Claims (10)
- 一种具有电磁耦合器的飞轮储能***,其特征在于,包括电动机、飞轮转子、电磁耦合器、变频器和发电机,所述电动机与所述飞轮转子相连以驱动所述飞轮转子旋转,所述电磁耦合器包括外转子和内转子,所述外转子套设所述内转子并与所述内转子之间间隔;所述飞轮转子与所述外转子传动连接,所述外转子产生旋转磁场带动所述内转子转动,所述变频器与所述外转子相连用于使所述旋转磁场的转速保持恒定,从而使所述内转子的转速保持恒定,所述内转子与所述发电机的输入端相连,所述发电机发电接入电网并向电网中输入具有稳定频率的电能;或者,所述飞轮转子与所述内转子传动连接,所述内转子产生旋转磁场带动所述外转子转动,所述变频器与所述外转子相连用于改变所述外转子的电流频率从而改变电流匹配的磁场转速,以便所述外转子的机械转速保持恒定,所述外转子与所述发电机的输入端相连,所述发电机发电接入电网并向电网中输入具有稳定频率的电能。
- 根据权利要求1所述的具有电磁耦合器的飞轮储能***,其特征在于,所述内转子包括内转子铁芯和内转子绕组,所述外转子包括外转子铁芯和外转子绕组,所述变频器与所述外转子绕组相连。
- 根据权利要求1所述的具有电磁耦合器的飞轮储能***,其特征在于,所述发电机为同步发电机。
- 根据权利要求1所述的具有电磁耦合器的飞轮储能***,其特征在于,所述电动机与电网相连并用于从电网取电,所述飞轮储能***具备释能状态和储能状态,在所述释能状态下,所述电动机待机,所述飞轮转子释放动能驱动所述发电机发电,所述发电机向电网中输入具有稳定频率的电能,在所述储能状态下,所述电动机从电网取电以驱动所述飞轮转子旋转,所述发电机空转。
- 根据权利要求4所述的具有电磁耦合器的飞轮储能***,其特征在于,所述飞轮储能***具备待机状态,在所述待机状态下,所述电动机待机,所述发电机空转。
- 根据权利要求1所述的具有电磁耦合器的飞轮储能***,其特征在于,还包括变速装置,所述飞轮转子与所述变速装置的输入端传动连接,所述变速装置的输出端与所述外转子或所述内转子传动连接,所述变速装置用于传导所述飞轮转子的转动惯量。
- 根据权利要求6所述的具有电磁耦合器的飞轮储能***,其特征在于,所述变速装置为具有固定变速比的变速装置。
- 根据权利要求6所述的具有电磁耦合器的飞轮储能***,其特征在于,所述变速装置为变速比可调的变速装置。
- 根据权利要求7或8所述的具有电磁耦合器的飞轮储能***,其特征在于,所述变速装置为齿轮变速器、液力变矩器、磁力变液器或永磁变速器。
- 根据权利要求6所述的具有电磁耦合器的飞轮储能***,其特征在于,所述飞轮转子的转速为100rpm-1000000rpm,所述变速装置的变速比为0.03-333。
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