CN114825394A - Flywheel energy storage system participating in power grid frequency modulation and control method thereof - Google Patents
Flywheel energy storage system participating in power grid frequency modulation and control method thereof Download PDFInfo
- Publication number
- CN114825394A CN114825394A CN202210374425.3A CN202210374425A CN114825394A CN 114825394 A CN114825394 A CN 114825394A CN 202210374425 A CN202210374425 A CN 202210374425A CN 114825394 A CN114825394 A CN 114825394A
- Authority
- CN
- China
- Prior art keywords
- switch
- energy storage
- storage system
- flywheel
- motor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- 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
-
- 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
- H02J3/241—The oscillation concerning frequency
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The flywheel energy storage system participating in power grid frequency modulation and the control method thereof are provided by the disclosure; the system comprises: a flywheel unit including a motor and a flywheel; the first switch is connected between the motor winding and the power grid; the auxiliary branch circuits are connected in parallel with two sides of the first switch and comprise a second switch and an auxiliary converter which are connected, and the auxiliary converter is used for driving the flywheel rotor to increase the speed to a rated speed in a starting stage; and a control unit. The method comprises the following steps: the method comprises the steps that in the starting stage, a first switch is controlled to be switched off, a second switch is controlled to be switched on, the rotating speed of a motor and a flywheel rotor is controlled to be increased from 0 by using an auxiliary converter, the auxiliary converter is enabled to quit operation when the rotating speed reaches a rated rotating speed, the second switch is switched off, and the first switch is controlled to be switched on when the grid voltage and the back electromotive force of the motor meet grid-connected conditions; in the frequency modulation stage, the flywheel energy storage system automatically participates in the frequency modulation of the power grid; and if the machine needs to be stopped for maintenance, the first switch is controlled to be disconnected. The system has the advantages of high response speed, high energy efficiency, low cost and high operation reliability.
Description
Technical Field
The disclosure belongs to the technical field of flywheel energy storage, and particularly relates to a flywheel energy storage system participating in power grid frequency modulation and a control method thereof.
Background
Energy storage is an important means for realizing the aim of 'double carbon', and the technologies of chemical battery energy storage, pumped storage, flywheel energy storage and the like in the current energy storage field play an important role in power grid frequency regulation. The flywheel energy storage is used as physical energy storage equipment and has the advantages of long service life, safe operation, high response speed and the like. At present, flywheel energy storage systems for power grid frequency modulation are all in a framework of combining a flywheel energy storage unit with a high-capacity and high-fundamental-frequency converter, the rated working rotating speed of a flywheel is an interval, and the power capacity of the converter is equivalent to that of a flywheel motor. In the working rotating speed interval, the flywheel motor and the converter both have full power output capacity. The flywheel energy storage system with the structure has the advantages of flexible control and large output energy, but also has the defects of high manufacturing cost, complex technical route and low energy efficiency.
Disclosure of Invention
The present disclosure is directed to solving, at least in part, one of the technical problems in the related art.
Therefore, the flywheel energy storage system participating in power grid frequency modulation, provided by the embodiment of the first aspect of the disclosure, has the advantages of fast response speed, high energy efficiency, low cost and high operational reliability, and includes:
the flywheel unit comprises a motor and a flywheel, and the motor is coaxially connected with a flywheel rotor;
a first switch connected between a winding of the motor and a power grid;
the auxiliary branch circuit is connected to two sides of the first switch in parallel and comprises a second switch and an auxiliary converter which are connected, and the auxiliary converter is used for driving the flywheel rotor to increase the speed to a rated speed in the starting stage of the flywheel energy storage system; and
and the control unit is used for controlling the first switch, the second switch and the auxiliary converter to be switched on and off according to the voltage of the power grid and the voltage of the motor.
The flywheel energy storage system participating in power grid frequency modulation provided by the embodiment of the first aspect of the disclosure has the following characteristics and beneficial effects:
compared with the flywheel energy storage system currently applied to power grid frequency modulation, the flywheel energy storage system participating in power grid frequency modulation provided by the embodiment of the first aspect of the disclosure has the advantages that the flywheel unit is directly and electrically connected with a power grid, so that the control response time is saved, and the frequency modulation response speed is increased; and a power electronic device is omitted, so that the system cost is reduced, and the overall energy efficiency and the operation reliability of the system are improved.
In some embodiments, the frequency of the no-load back emf of the motor is 50Hz when the flywheel rotor reaches an operating point at the rated speed, the magnitude of the no-load back emf of the motor being equal to the rated magnitude of the grid voltage.
In some embodiments, the electric machine is a permanent magnet synchronous machine.
In some embodiments, each of the first switch and the second switch is a three-phase switch, one end of each phase of the first switch and the second switch is respectively connected to a corresponding winding of the electric motor, and the other end of each phase of the first switch and the second switch is respectively connected to a corresponding phase of the power grid.
In some embodiments, when the first switch is open and the second switch is closed, the flywheel energy storage system is in a startup phase, and when the first switch is closed and the second switch is open, the flywheel energy storage system is in a frequency modulation phase.
In some embodiments, the auxiliary converter operates only during a startup phase of the flywheel energy storage system.
In some embodiments, the control unit is configured with the following control instructions:
when the flywheel energy storage system is in a starting stage, the first switch is controlled to be switched off, the second switch is controlled to be switched on, the motor is controlled by the auxiliary converter to drive the flywheel rotor to increase the speed from 0, when the rotating speed of the flywheel rotor reaches a rated rotating speed, the second switch is controlled to be switched off, the auxiliary converter is enabled to quit operation, the grid voltage and the back electromotive force of the motor are obtained in real time, when the phases and the amplitudes of the grid voltage and the back electromotive force of the motor meet the synchronous grid-connection condition, the first switch is controlled to be switched on, the second switch is controlled to be switched off, and the flywheel energy storage system finishes the starting stage and enters a frequency modulation stage; in the frequency modulation stage, the voltage of the motor is synchronous with the voltage of the power grid; and if the machine needs to be stopped for maintenance, the first switch is controlled to be switched off, and the rotating speeds of the motor and the flywheel rotor are gradually reduced to 0.
The control method for the flywheel energy storage system participating in power grid frequency modulation provided in the embodiment of the second aspect of the present disclosure is a flywheel energy storage system provided in the embodiment of the first aspect of the present disclosure, and the control method includes:
in the starting stage, the control unit controls the first switch to be switched off and the second switch to be switched on, so that the auxiliary converter is put into operation, the auxiliary converter controls the rotating speed of the motor and the flywheel rotor to start increasing from 0, and when the rotating speed reaches a rated rotating speed, the auxiliary converter is stopped from operating and the second switch is switched off; the control unit acquires the grid voltage and the counter electromotive force of the motor in real time, and controls the first switch to be closed when the phases and amplitudes of the grid voltage and the counter electromotive force of the motor are consistent, so that synchronous grid connection is realized;
in the frequency modulation stage, the flywheel energy storage system automatically participates in the frequency modulation of the power grid;
and if the machine needs to be stopped for maintenance, the control unit controls the first switch to be disconnected.
Drawings
Fig. 1 is a schematic structural diagram of a flywheel energy storage system participating in grid frequency modulation according to an embodiment of the first aspect of the present disclosure.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
On the contrary, this application is intended to cover any alternatives, modifications, equivalents, and alternatives that may be included within the spirit and scope of the application as defined by the appended claims. Furthermore, in the following detailed description of the present application, certain specific details are set forth in order to provide a better understanding of the present application. It will be apparent to one skilled in the art that the present application may be practiced without these specific details.
Referring to fig. 1, a flywheel energy storage system participating in grid frequency modulation provided in an embodiment of the first aspect of the present disclosure includes:
the flywheel unit 1 comprises a motor 102 and a flywheel, wherein the motor 102 is coaxially connected with a flywheel rotor 101;
a first switch S1, the first switch S1 being connected between the winding of the motor 102 and the grid;
the auxiliary branch circuits are connected to two sides of the first switch S1 in parallel, each auxiliary branch circuit comprises a second switch S2 and an auxiliary converter 2 which are connected, and the auxiliary converters 2 are used for driving the flywheel rotor 102 to increase the speed to the rated speed in the starting stage of the flywheel energy storage system; and
and a control unit 3, wherein the control unit 3 is used for controlling the opening and closing of the first switch S1, the second switch S2 and the auxiliary converter 2 according to the power grid voltage and the voltage of the motor 102.
In some embodiments, the flywheel rotor 101 has a large rotational inertia and is mechanically supported by magnetic bearings with very low friction losses. The motor 102 is a permanent magnet synchronous motor, when the flywheel rotor 101 reaches a working point of a rated rotating speed, the frequency of the no-load back electromotive force of the motor 102 is 50Hz, and the amplitude of the no-load back electromotive force is equal to the rated amplitude of the voltage of a power grid where the no-load back electromotive force is located, so that the normal work of the flywheel energy storage system is guaranteed. In fact, the frequency of the flywheel energy storage system is synchronous with the frequency of the power grid, when the frequency of the power grid fluctuates, the frequency of the flywheel energy storage system also fluctuates, the original rotational inertia is broken, the frequency of the power grid is forced to fluctuate in a smaller amplitude, and therefore the purpose of frequency modulation of the flywheel energy storage system on the power grid is achieved.
In some embodiments, the first switch S1 and the second switch S2 are three-phase switches, one end of each phase of the first switch S1 and the second switch S2 is connected to a corresponding winding of the motor 102, and the other end of each phase of the first switch S1 and the second switch S2 is connected to a corresponding phase of the grid. The flywheel energy storage system is in different working states by switching the opening and closing states of the first switch S1 and the second switch S2, specifically, when the first switch S1 is opened and the second switch S2 is closed, the flywheel energy storage system is in a starting stage, and when the first switch S1 is closed and the second switch S2 is opened, the flywheel energy storage system is in a frequency modulation stage.
In some embodiments, the auxiliary converter 2 is only put into operation during the start-up phase of the present flywheel energy storage system, and is configured to control the motor 102 to drive the flywheel rotor 101 to increase the speed from 0, and when the rotational speed of the flywheel rotor 101 reaches the rated rotational speed, the first switch S1 is closed, the second switch S2 is opened, and the auxiliary converter 2 is taken out of operation. The auxiliary converter 2 adopts a general permanent magnet synchronous motor controller, has low requirements on power and rotating speed control, and can drive the motor 102 of the flywheel energy storage system from 0 speed to rated rotating speed.
In some embodiments, the control unit 3 is used to control the operation of the remaining electrical components in the flywheel energy storage system. Specifically, when the flywheel energy storage system is in a starting stage, the control unit 3 controls the first switch S1 to be opened, the second switch S2 to be closed, the auxiliary converter 2 starts to operate, the auxiliary converter 2 controls the motor 102 to drive the flywheel rotor 101 to increase the speed from 0, when the rotating speed of the flywheel rotor 101 reaches a rated rotating speed, the control unit 3 controls the second switch S2 to be opened, the first switch S1 is kept to be opened, the auxiliary converter 2 stops operating, the control unit 3 obtains the grid voltage and the back electromotive force of the motor 102 in real time, when the phases and amplitudes of the grid voltage and the back electromotive force of the motor 102 both accord with the synchronization condition (namely the phases and amplitudes of the back electromotive force of the motor 102 are respectively equal to those of the grid), the control unit 3 controls the first switch S1 to be closed, the second switch S2 to be kept to be opened, the flywheel energy storage system finishes the starting stage and enters a frequency modulation stage, in the frequency modulation stage, the three-phase voltage of the motor 102 is synchronous with the three-phase voltage of the power grid, and the flywheel energy storage system can automatically and quickly adjust the frequency of the power grid without any control algorithm and power electronic equipment, so that the flywheel energy storage system is extremely low in loss and extremely high in reliability; if the flywheel energy storage system needs to be stopped for maintenance, the control unit 3 controls the first switch S1 to be switched off, the rotating speeds of the motor 102 and the flywheel rotor 101 gradually decrease to 0, and the flywheel energy storage system stops working.
The control method for the flywheel energy storage system participating in power grid frequency modulation provided by the embodiment of the second aspect of the disclosure includes:
firstly, the flywheel energy storage system is started, the control unit 3 controls the first switch S1 to be switched off and the second switch S2 to be switched on, the auxiliary converter is put into operation, the auxiliary converter 2 controls the rotating speed of the motor 102 and the flywheel rotor 101 to start to increase from 0, when the rotating speed reaches the rated rotating speed, the auxiliary converter 2 quits operation, the second switch S2 is switched off, and the first switch S1 is switched off continuously. The control unit 3 acquires the grid voltage and the counter electromotive force of the motor 102 in real time, and controls the first switch S1 to be closed when the grid voltage and the counter electromotive force of the motor 102 both conform in phase and amplitude, so that synchronous grid connection is realized. And then the flywheel energy storage system enters a frequency modulation stage.
And secondly, the flywheel energy storage system automatically participates in power grid frequency modulation in a frequency modulation stage, no power electronic device or algorithm is involved, and the self rotary inertia is completely injected into the power grid system.
And thirdly, if the machine needs to be stopped for maintenance, the first switch S1 is turned off.
In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the present disclosure have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined by the claims and their equivalents.
Claims (8)
1. A flywheel energy storage system participating in power grid frequency modulation is characterized by comprising:
the flywheel unit comprises a motor and a flywheel, and the motor is coaxially connected with a flywheel rotor;
a first switch connected between a winding of the motor and a power grid;
the auxiliary branch circuit is connected to two sides of the first switch in parallel and comprises a second switch and an auxiliary converter which are connected, and the auxiliary converter is used for driving the flywheel rotor to increase the speed to a rated speed in the starting stage of the flywheel energy storage system; and
and the control unit is used for controlling the first switch, the second switch and the auxiliary converter to be switched on and off according to the voltage of the power grid and the voltage of the motor.
2. The flywheel energy storage system of claim 1, wherein the frequency of the no-load back emf of the motor is 50Hz at the point where the flywheel rotor reaches the rated speed, and the magnitude of the no-load back emf of the motor is equal to the rated magnitude of the grid voltage.
3. The flywheel energy storage system of claim 1, wherein the electric machine is a permanent magnet synchronous machine.
4. The flywheel energy storage system of claim 1, wherein the first switch and the second switch are three-phase switches, one end of each phase of the first switch and the second switch is connected to a corresponding winding of the electric machine, and the other end of each phase of the first switch and the second switch is connected to a corresponding phase of the power grid.
5. The flywheel energy storage system of claim 1, wherein the flywheel energy storage system is in a startup phase when the first switch is open and the second switch is closed, and wherein the flywheel energy storage system is in a frequency modulation phase when the first switch is closed and the second switch is open.
6. The flywheel energy storage system of claim 1, wherein the auxiliary converter operates only during a startup phase of the flywheel energy storage system.
7. The flywheel energy storage system according to claim 1, wherein the control unit is configured with the following control commands:
when the flywheel energy storage system is in a starting stage, the first switch is controlled to be switched off, the second switch is controlled to be switched on, the motor is controlled by the auxiliary converter to drive the flywheel rotor to start accelerating from 0, when the rotating speed of the flywheel rotor reaches a rated rotating speed, the second switch is controlled to be switched off, the auxiliary converter is enabled to quit operation, the grid voltage and the counter electromotive force of the motor are obtained in real time, when the phases and the amplitudes of the grid voltage and the counter electromotive force of the motor meet the synchronous grid-connection condition, the first switch is controlled to be switched on, and the flywheel energy storage system finishes the starting stage and enters a frequency modulation stage; in the frequency modulation stage, the voltage of the motor is synchronous with the voltage of the power grid; and if the machine needs to be stopped for maintenance, the first switch is controlled to be switched off, and the rotating speeds of the motor and the flywheel rotor are gradually reduced to 0.
8. A control method of a flywheel energy storage system participating in grid frequency modulation, wherein the flywheel energy storage system is the flywheel energy storage system according to any one of claims 1-7, the control method comprising:
in the starting stage, the control unit controls the first switch to be switched off and the second switch to be switched on, so that the auxiliary converter is put into operation, the auxiliary converter controls the rotating speed of the motor and the flywheel rotor to start increasing from 0, and when the rotating speed reaches a rated rotating speed, the auxiliary converter is stopped from operating and the second switch is switched off; the control unit acquires the grid voltage and the counter electromotive force of the motor in real time, and controls the first switch to be closed when the phases and amplitudes of the grid voltage and the counter electromotive force of the motor are consistent, so that synchronous grid connection is realized;
in the frequency modulation stage, the flywheel energy storage system automatically participates in the frequency modulation of the power grid;
and if the machine needs to be stopped for maintenance, the control unit controls the first switch to be disconnected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210374425.3A CN114825394A (en) | 2022-04-11 | 2022-04-11 | Flywheel energy storage system participating in power grid frequency modulation and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210374425.3A CN114825394A (en) | 2022-04-11 | 2022-04-11 | Flywheel energy storage system participating in power grid frequency modulation and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114825394A true CN114825394A (en) | 2022-07-29 |
Family
ID=82534856
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210374425.3A Pending CN114825394A (en) | 2022-04-11 | 2022-04-11 | Flywheel energy storage system participating in power grid frequency modulation and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114825394A (en) |
-
2022
- 2022-04-11 CN CN202210374425.3A patent/CN114825394A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10784808B2 (en) | Variable speed generator-motor apparatus and variable speed generator-motor system | |
| JP4112930B2 (en) | Inverter device | |
| JP2009185816A (en) | High frequency electrically driven device with multipolar motor for gas pipeline and storage compression use | |
| CN102055207B (en) | Intelligent power control unit for low voltage ride through and application thereof | |
| CN108336941B (en) | Control circuit, control method, permanent magnet synchronous motor, compressor and storage medium | |
| JP2012050181A (en) | Wind power generator | |
| JP2015511108A (en) | Operation method of electric unit for pumped storage power plant | |
| CN110797891A (en) | Flywheel energy storage system of double three-phase brushless direct current motor and control method thereof | |
| CN105071726A (en) | Switched reluctance wind power generation grid-connected system control method | |
| EP3443276B1 (en) | Compressor unit, refrigeration circuit comprising the same and method of operating a compressor unit | |
| CN108847796B (en) | Reluctance type starting control method and system for three-stage brushless synchronous motor | |
| US20090021020A1 (en) | Variable speed drive system | |
| CN217563338U (en) | Flywheel energy storage system participating in power grid frequency modulation | |
| CN114825394A (en) | Flywheel energy storage system participating in power grid frequency modulation and control method thereof | |
| CN113659629B (en) | Synchronous computerized power electronic grid-connected device and control method thereof | |
| CN109274300B (en) | Starting and excitation system and method for gas turbine generator set | |
| CN201966629U (en) | Low voltage ride through intelligent power control unit | |
| JPH0564554B2 (en) | ||
| CN111245310A (en) | Asynchronous starting permanent magnet synchronous motor quick starting method based on torque characteristics | |
| CN213717874U (en) | Two-in-one high-voltage frequency conversion control system | |
| RU2701151C1 (en) | Electromechanical insert between two power systems | |
| CN116094056B (en) | Electrical main wiring structure and method of full-power variable-frequency pumped storage unit | |
| CN114629390B (en) | Multiplexing structure and method for starting controller of aviation three-stage starting/generating system | |
| RU2496209C1 (en) | Standby method of frequency converters in system of electric actuators of circulating pumps of power facility | |
| CN219349019U (en) | Simple and easy positive and negative rotation test system of converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |