CN116388234B - Control method, system, controller and storage medium of grid-connected power generation system - Google Patents

Control method, system, controller and storage medium of grid-connected power generation system Download PDF

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Publication number
CN116388234B
CN116388234B CN202310666908.5A CN202310666908A CN116388234B CN 116388234 B CN116388234 B CN 116388234B CN 202310666908 A CN202310666908 A CN 202310666908A CN 116388234 B CN116388234 B CN 116388234B
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grid
synchronous
power
synchronous motor
deviation value
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CN116388234A (en
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关东英
鄢秋亮
刘�东
贺智威
白宁
杨晶
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Candela Shenzhen New Energy Technology Co Ltd
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Candela Shenzhen New Energy Technology Co Ltd
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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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H02J3/241—The oscillation concerning frequency
    • 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
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • 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
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1885—Arrangements for adjusting, eliminating or compensating reactive power in networks using rotating means, e.g. synchronous generators
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/48—Controlling the sharing of the in-phase component
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • 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

Abstract

The application relates to the technical field of grid regulation, and discloses a control method, a system, a controller and a storage medium of a grid-connected power generation system, wherein the method is applied to the grid-connected power generation system and comprises the following steps: acquiring a frequency deviation value between the instantaneous frequency of the power grid and a preset rated frequency of the power grid; when the frequency deviation value is not equal to 0, the two ends of the coupler are in a connection state, and the synchronous motor and the synchronous tuner realize inertia response to an alternating current power grid; when the frequency deviation value is positive and is larger than the preset forward dead zone frequency, controlling the motor controller to control the synchronous motor to reduce power output; and when the frequency deviation value is negative and smaller than the preset negative dead frequency, controlling the motor controller to control the synchronous motor to increase the power output. Therefore, the method and the device provide enough mechanical inertia supporting capacity for the alternating current power grid, avoid impact caused by instantaneous change of load on the power grid side, and participate in primary frequency modulation of the alternating current power grid, so that the frequency stability of the power grid is autonomously supported.

Description

Control method, system, controller and storage medium of grid-connected power generation system
Technical Field
The invention relates to the technical field of power grid regulation, in particular to a control method, a system, a controller and a storage medium of a grid-connected power generation system.
Background
The traditional power generation mode mainly comprises the steps that fossil fuel is combusted in a thermal power plant to drive a gas turbine unit to generate power, and new energy power generation such as photovoltaic power, wind power and tide inevitably enters a rapid development stage and gradually replaces traditional fossil fuel power generation along with the national promulgation of a 'two-carbon' strategic goal.
Along with the continuous increase of the installed quantity of new energy power generation, the installed quantity of traditional fossil fuel power generation is reduced, so that the primary frequency modulation capability of the traditional fossil fuel power generation to the power grid is weakened, and the stability of the power grid is reduced. At present, the new energy grid connection is commonly realized by adopting a power electronic device, and the grid connection mode lacks sufficient mechanical inertia supporting capability, so that the impact of the load transient change on the power grid side is easily caused; the inertia of the new energy grid connection mainly comes from virtual inertia generated by an inversion device and a virtual inertia control algorithm, and as the virtual inertia cannot be naturally coupled with an alternating current power grid to run, the disturbance of the alternating current power grid cannot be responded, primary frequency modulation of the alternating current power grid cannot be participated, and further the frequency stability of the power grid cannot be independently supported.
Disclosure of Invention
Based on the above, it is necessary to provide a control method, a system, a controller and a storage medium for a grid-connected power generation system, aiming at the technical problems that in the prior art, when new energy is grid-connected, the lack of sufficient mechanical inertia supporting capability causes the impact of instantaneous load change on the side of a power grid, the primary frequency modulation of the alternating current power grid cannot be participated, and further the frequency stability of the power grid cannot be independently supported.
In a first aspect, the present application provides a control method of a grid-connected power generation system, where the method is applied to the grid-connected power generation system, and the grid-connected power generation system includes: the synchronous motor comprises a motor controller, a synchronous motor, a coupler, a synchronous camera, a grid-connected switch and a detection device; the motor controller is used for being connected with the power generation unit and taking power from the power generation unit, is connected with the synchronous motor and can drive the synchronous motor to rotate; the synchronous motor is connected with one end of the coupler, the other end of the coupler is connected with the synchronous speed regulator, and when the two ends of the coupler are in a connection state, the synchronous motor can drive the synchronous speed regulator to synchronously rotate for generating electricity; the synchronous phase regulator is connected with the grid-connected switch and can be connected with an alternating current power grid through the grid-connected switch, and the detection device is used for detecting the power grid instantaneous frequency of the alternating current power grid;
The method comprises the following steps:
acquiring a frequency deviation value between the instantaneous frequency of the power grid and a preset rated frequency of the power grid;
when the frequency deviation value is not equal to 0, two ends of the coupler are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the alternating current power grid;
when the frequency deviation value is positive and is larger than a preset forward dead zone frequency, controlling the motor controller to control the synchronous motor to reduce power output;
and when the frequency deviation value is negative and smaller than a preset negative dead frequency, controlling the motor controller to control the synchronous motor to increase power output.
In a second aspect, the present application proposes a grid-connected power generation system, including: the system comprises a system controller, a motor controller, a synchronous motor, a coupler, a synchronous camera, a grid-connected switch and a detection device; the motor controller is used for being connected with the power generation unit and taking power from the power generation unit, is connected with the synchronous motor and can drive the synchronous motor to rotate; the synchronous motor is connected with one end of the coupler, the other end of the coupler is connected with the synchronous speed regulator, and when the two ends of the coupler are in a connection state, the synchronous motor can drive the synchronous speed regulator to synchronously rotate for generating electricity; the synchronous phase regulator is connected with the grid-connected switch and can be connected with an alternating current power grid through the grid-connected switch, and the detection device is used for detecting the power grid instantaneous frequency of the alternating current power grid; the system controller comprises a memory storing a computer program and a processor adapted to implement the steps of the control method of the grid-connected power generation system according to any one of the first aspects when the computer program is executed.
In a third aspect, the present application proposes a computer readable storage medium storing a computer program which, when executed by a processor, implements the steps of the control method of a grid-connected power generation system according to any one of the first aspects.
In a fourth aspect, the present application proposes a system controller of a grid-connected power generation system, comprising a memory, a processor, the memory storing a computer program executable on the processor, the processor implementing the steps of the control method of a grid-connected power generation system according to any one of the first aspects when executing the computer program.
The application has the following technical effects:
(1) In the application, when the frequency deviation value is not equal to 0, the two ends of the coupler are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the AC power grid, so that the combination of the synchronous motor and the synchronous regulator provides enough mechanical inertia supporting capability for the AC power grid to avoid impact of load transient change at the power grid side and improve the stability of the power grid.
(2) In the application, when the frequency deviation value is positive and is larger than the preset positive dead zone frequency, the motor controller is controlled to control the synchronous motor to reduce the power output, and when the frequency deviation value is negative and is smaller than the preset negative dead zone frequency, the motor controller is controlled to control the synchronous motor to increase the power output, so that the frequency of the alternating current power grid is quickly responded and adjusted, the primary frequency modulation of the alternating current power grid is realized, and the frequency stability of the power grid is independently supported.
(3) A large number of power electronic devices are used in the traditional new energy grid connection process, so that harmonic waves which harm a power grid are generated, particularly the harmonic wave content after high-proportion new energy grid connection is larger and larger, and the power grid is crashed when serious; meanwhile, the power electronic device in the grid-connected system can be directly damaged by the power grid fault, and the system can be destroyed and economic loss can be caused. According to the application, the synchronous motor is provided to drive the synchronous phase-adjusting device to synchronously rotate to generate power so as to realize secondary power generation grid connection, so that the influence of harmonic waves of a power electronic device in the new energy station on an alternating current power grid can be isolated, the influence of an alternating current power grid fault on an internal power grid of the new energy station can be isolated, the stability of the power grid is improved, and the safety of the internal power grid of the new energy station is protected.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Wherein:
FIG. 1 is a schematic diagram of an application environment of a control method of a grid-connected power generation system in one embodiment;
FIG. 2 is a flow chart of inertia response and primary frequency modulation of a control method of a grid-connected power generation system according to one embodiment;
FIG. 3 is a flow chart of reactive power regulation of a control method of a grid-tied power generation system in one embodiment;
FIG. 4 is a flow chart of a grid tie of a control method of a grid tie power generation system in one embodiment;
FIG. 5 is a block diagram of a grid-tied power generation system in one embodiment;
fig. 6 is a block diagram of a system controller of the grid-connected power generation system in one embodiment.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In order to better understand the control method, system, controller and storage medium of the grid-connected power generation system disclosed by the application, firstly, an application environment of the control method of the grid-connected power generation system is described, specifically, the control method of the grid-connected power generation system is used for controlling the grid-connected power generation system, and the grid-connected power generation system comprises: the synchronous motor comprises a motor controller 1, a synchronous motor 2, a coupler 4, a synchronous regulator 5, a grid-connected switch S2 and a detection device 8; the motor controller 1 is used for being connected with a power generation unit and taking power from the power generation unit, and the motor controller 1 is connected with the synchronous motor 2 and can drive the synchronous motor 2 to rotate; the synchronous motor 2 is connected with one end of the coupler 4, the other end of the coupler 4 is connected with the synchronous regulator 5, and when the two ends of the coupler 4 are in a connection state, the synchronous motor 2 can drive the synchronous regulator 5 to synchronously rotate for generating electricity; the synchronous regulator 5 is connected with the grid-connected switch S2 and can be connected with an ac power grid through the grid-connected switch S2, and the detecting device 8 is used for detecting the grid instantaneous frequency of the ac power grid. A large number of power electronic devices are used in the traditional new energy grid connection process, so that harmonic waves which harm a power grid are generated, particularly the harmonic wave content after high-proportion new energy grid connection is larger and larger, and the power grid is crashed when serious; meanwhile, the power electronic device in the grid-connected system can be directly damaged by the power grid fault, and the system can be destroyed and economic loss can be caused. According to the application, the synchronous motor is provided to drive the synchronous phase-adjusting device to synchronously rotate to generate power so as to realize secondary power generation grid connection, so that the influence of harmonic waves of a power electronic device in the new energy station on an alternating current power grid can be isolated, the influence of an alternating current power grid fault on an internal power grid of the new energy station can be isolated, the stability of the power grid is improved, and the safety of the internal power grid of the new energy station is protected.
The power generation unit is a power station that generates electricity. Optionally, the power generation unit is a new energy power generation unit. For example, the power generation unit is a new energy station that generates power using new energy such as photovoltaic, wind power, and tide. The power generated by the power generation unit needs to be connected to an alternating current power grid. The grid-connected power generation system is used for connecting the power generated by the power generation unit to an alternating current power grid.
The detection device 8 includes: the first frequency detection sensor is configured to detect, in real time, a grid instantaneous frequency of the ac power grid, for example, one end of the grid-connected switch S2 connected to the ac power grid is detected in real time, so as to detect the grid instantaneous frequency of the ac power grid. The first frequency detection sensor is a sensor for detecting a grid instantaneous frequency of the grid.
Optionally, the grid-connected power generation system further includes: the gear set is connected between the output shaft of the synchronous motor and the flywheel rotor. So that an inertia response to the ac network is achieved by means of the flywheel rotor, the synchronous motor 2 and the synchronous rectifier 5.
The gear set includes: the driving gear is meshed with the driven gear, the driving gear is connected between the synchronous motor and one end of the coupler, and the shaft of the flywheel rotor is connected with the driven gear.
It can be understood that the motor controller 1 takes electricity from a dc bus of the power generation unit, the motor controller 1 inverts the taken electricity from dc to ac, and the ac obtained by the inversion is input to the synchronous motor 2; the rotating speed of the synchronous motor 2 is controlled by the motor controller 1, and the synchronous motor 2 keeps running at 50HZ in order to meet the grid connection requirement; the synchronous motor 2 transmits power to the synchronous speed regulator 5 through the coupler 4, the synchronous motor 2 and the synchronous speed regulator 5 keep synchronous motion, and the synchronous motor 2 can drive the synchronous speed regulator 5 to synchronously rotate for generating power; the power generated by the synchronous regulator 5 is connected through a grid-connected switch S2, wherein grid connection refers to the combination with an alternating current power grid.
Optionally, the grid-connected power generation system further includes a grid-connected transformer, an input end of the grid-connected transformer is connected with the synchronous phase-regulating device, an output end of the grid-connected transformer is connected with the grid-connected switch and can be connected with the ac power grid through the grid-connected switch, and the grid-connected transformer is used for boosting electric energy output by the synchronous phase-regulating device.
It can be understood that a system controller can be arranged in the grid-connected power generation system to load a program file for realizing the control method of the grid-connected power generation system, a switch control circuit can be arranged in the grid-connected power generation system to realize the method steps of the control method of the grid-connected power generation system, and a system can be arranged outside the grid-connected power generation system to load a program file for realizing the control method of the grid-connected power generation system.
Optionally, when the grid-connected power generation system comprises a grid-connected transformer, the synchronous phase-regulating device 5 is connected with the grid through the grid-connected transformer and the grid-connected switch S2.
The grid-connected power generation system is a power generation system and can be arranged in new energy stations such as photovoltaic, wind power and the like. The grid-connected power generation system can be used as a power generation side together with a traditional thermal power station or independently used as the power generation side to imitate the traditional thermal power station so as to supply power for a rear-end load. The grid-connected power generation system is a regulator of an alternating current power grid at the same time, for example, if the power generation power is not matched with the power consumption of the alternating current power grid, the frequency of the alternating current power grid can rise or fall, and the grid-connected power generation system can be controlled to have less output mechanical power and less power generation or more output mechanical power and more power generation at the moment so as to realize the regulation of the frequency of the alternating current power grid; of course, the synchronous regulator of the grid-connected power generation system can also be used as a regulator of reactive power.
The motor controller 1, the synchronous motor 2, the coupling 4, the synchronous motor 5, the grid-connected switch S2, the detecting device 8, etc. are only schematically shown, and specific structures, sizes, shapes, positions/installation modes, etc. can be adaptively adjusted according to actual requirements, and the application is not limited herein.
The application scenario used by the control method of the grid-connected power generation system is described above, and the control method, the system, the controller and the storage medium of the grid-connected power generation system are described in detail below.
As shown in fig. 2, a control method of a grid-connected power generation system is provided, where the method is applied to the grid-connected power generation system, and the grid-connected power generation system includes: the synchronous motor comprises a motor controller, a synchronous motor, a coupler, a synchronous camera, a grid-connected switch and a detection device; the motor controller is used for being connected with the power generation unit and taking power from the power generation unit, is connected with the synchronous motor and can drive the synchronous motor to rotate; the synchronous motor is connected with one end of the coupler, the other end of the coupler is connected with the synchronous speed regulator, and when the two ends of the coupler are in a connection state, the synchronous motor can drive the synchronous speed regulator to synchronously rotate for generating electricity; the synchronous phase regulator is connected with the grid-connected switch and can be connected with an alternating current power grid through the grid-connected switch, and the detection device is used for detecting the power grid instantaneous frequency of the alternating current power grid;
the method comprises the following steps:
S1: acquiring a frequency deviation value between the instantaneous frequency of the power grid and a preset rated frequency of the power grid;
the power grid instantaneous frequency is the alternating current power supply frequency of the alternating current power grid detected in real time.
The preset rated frequency of the power grid is the rated alternating current power supply frequency of the alternating current power grid. Optionally, the preset rated frequency of the power grid is 50HZ.
Specifically, the power grid instantaneous frequency of the alternating current power grid sent by the detection device is obtained, the latest obtained power grid instantaneous frequency is subtracted by the preset power grid rated frequency, and the subtracted data are used as frequency deviation values.
S2: when the frequency deviation value is not equal to 0, two ends of the coupler are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the alternating current power grid;
specifically, when the frequency deviation value is not equal to 0, it means that the instantaneous frequency of the ac power grid at this time does not meet the preset requirement (preset rated frequency of the power grid), the ac power grid needs to be subjected to frequency modulation, firstly, two ends of the coupling are ensured to be in a connection state, and at this time, inertia response to the ac power grid is realized through the synchronous motor and the synchronous tuner, so that the frequency change rate is delayed, the frequency is prevented from falling rapidly, and when primary frequency modulation is required, time is won for primary frequency modulation through inertia response to the ac power grid through the synchronous motor and the synchronous tuner.
The rotor of the synchronous motor and the rotor of the synchronous camera form a rotor system, and inertia support is provided through the rotational inertia of the rotor system so as to realize inertia response to the alternating current power grid. The inertial support is a short-time impact type power support.
The moment of inertia is mechanical inertia, and is constant for a power generation system formed by the synchronous motor and the synchronous regulator.
S3: when the frequency deviation value is positive and is larger than a preset forward dead zone frequency, controlling the motor controller to control the synchronous motor to reduce power output;
frequency modulation is divided into two phases: a phase of inertia response and a phase of primary frequency modulation. The phase of inertia response wins time for the phase of primary frequency modulation. For example, step S2 implements the inertia response phase, step S3 implements the primary frequency modulation phase, and step S4 implements the primary frequency modulation phase. The phase of the inertia response is the frequency modulation of the passive response. The primary frequency modulation stage is actively performed frequency modulation.
When the frequency deviation value is outside the dead zone frequency range, the primary frequency modulation stage is required to be entered, wherein the dead zone frequency range is a range from a preset negative dead zone frequency to a preset positive dead zone frequency. When the frequency deviation value is within the dead band frequency range, no primary frequency modulation stage is required.
Specifically, when the frequency deviation value is positive and is greater than the preset forward dead frequency, it means that primary frequency modulation is needed, and because the frequency deviation value is positive, it indicates that the active power of the ac power grid is excessive, that is, the load of the ac power grid is insufficient, at this time, if the synchronous motor maintains the original mechanical power output, the rotation speed of the rotor system formed by the synchronous motor and the synchronous modulator will continue to rise, so that in order to inhibit the frequency of the ac power grid from continuously increasing, the power output to the ac power grid needs to be reduced, a control signal is sent to the motor controller for controlling the synchronous motor to reduce the power output. And reducing the mechanical power input by the synchronous motor to the synchronous tuning machine by reducing the power output of the synchronous motor, so that the electromagnetic power output by the synchronous tuning machine to the alternating current power grid is reduced, namely the generated power of the synchronous tuning machine is reduced, so that the load of the alternating current power grid and the generated power of the synchronous tuning machine reach new balance until the frequency of the alternating current power grid is recovered to be normal, and then the primary frequency modulation action is ended.
Optionally, the frequency of the ac power grid is restored, i.e. the frequency deviation value is equal to 0.
Optionally, the preset forward dead band frequency is 0.03HZ. It will be appreciated that the predetermined forward dead band frequency may be other values, such as, but not limited to, values between 0.025HZ and 0.035 HZ.
S4: and when the frequency deviation value is negative and smaller than a preset negative dead frequency, controlling the motor controller to control the synchronous motor to increase power output.
Specifically, when the frequency deviation value is negative and smaller than the preset negative dead frequency, it means that primary frequency modulation is needed, and because the frequency deviation value is negative, the active power shortage of the ac power grid is indicated, that is, the load of the ac power grid is excessive, at this time, if the synchronous motor maintains the original mechanical power output, the rotation speed of the rotor system formed by the synchronous motor and the synchronous modulator will further decrease, in order to inhibit the frequency of the ac power grid from further decreasing, the power output to the ac power grid needs to be increased, so a control signal is sent to the motor controller for controlling the synchronous motor to increase the power output. And increasing the mechanical power input by the synchronous motor to the synchronous regulator by increasing the power output of the synchronous motor, so that the electromagnetic power output by the synchronous regulator to the AC power grid is also increased, namely the generated power of the synchronous regulator is increased to supplement the active power shortage of the AC power grid, so that the load of the AC power grid and the generated power of the synchronous regulator reach new balance until the frequency of the AC power grid is recovered to be normal, and then the primary frequency regulation action is ended.
Optionally, the preset negative dead band frequency is-0.03 HZ. It will be appreciated that the predetermined negative dead band frequency may also be other values, such as, but not limited to, values between-0.035 HZ and-0.025 HZ.
In this embodiment, when the frequency deviation value is not equal to 0, two ends of the coupling are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the ac power grid, so that the combination of the synchronous motor and the synchronous regulator provides sufficient mechanical inertia supporting capability for the ac power grid to avoid impact caused by instantaneous load change at the power grid side, and improve stability of the power grid. When the frequency deviation value is positive and is larger than a preset positive dead zone frequency, the motor controller is controlled to control the synchronous motor to reduce power output, and when the frequency deviation value is negative and smaller than a preset negative dead zone frequency, the motor controller is controlled to control the synchronous motor to increase power output, so that the frequency of an alternating current power grid is quickly responded and adjusted, primary frequency modulation participating in the alternating current power grid is realized, and further the frequency stability of the power grid is autonomously supported. The synchronous motor drives the synchronous phase-adjusting device to synchronously rotate to generate power so as to realize secondary power generation grid connection, so that the influence of harmonic waves of power electronic devices in the new energy station on the alternating current power grid can be isolated, the influence of the alternating current power grid fault on the internal power grid of the new energy station can be isolated, the stability of the power grid is improved, and the safety of the internal power grid of the new energy station is protected.
In one embodiment, the grid-connected power generation system further comprises: the gear set is connected between the output shaft of the synchronous motor and the flywheel rotor;
when the frequency deviation value is not equal to 0, two ends of the coupler are in a connection state, and the step of enabling the synchronous motor and the synchronous regulator to realize inertia response to the alternating current power grid comprises the following steps:
s21: generating an inertia response instruction when the frequency deviation value is not equal to 0;
specifically, when the frequency deviation value is not equal to 0, it means that the instantaneous frequency of the ac power grid at this time does not meet the preset requirement (the preset rated frequency of the power grid), the ac power grid needs to be tuned, and first, the inertia response stage needs to be entered, and the time is won for primary tuning in the primary tuning stage, so that an inertia response instruction is generated.
S22: and controlling the frequency of working current of the synchronous motor and the synchronous camera according to the inertia response instruction, and enabling two ends of the coupler to be in a connection state so as to enable the flywheel rotor, the synchronous motor and the synchronous camera to realize inertia response to the alternating current power grid.
Specifically, a control signal is sent according to the inertia response instruction, the synchronous motor and the synchronous tuning machine are controlled through the control signal so as to ensure that the frequencies of working currents of the synchronous motor and the synchronous tuning machine are kept unchanged, and the control signal is sent to the coupler according to the inertia response instruction so as to ensure that two ends of the coupler are in a connection state, and at the moment, the flywheel rotor, the synchronous motor and the synchronous tuning machine jointly respond to inertia of an alternating current power grid so as to realize passive response frequency modulation.
The number of flywheel rotors is at least one. When the number of the flywheel rotors is plural, the respective flywheel rotors are connected in parallel, thereby forming an inertial flywheel having a large mass.
In this embodiment, each of the flywheel rotor, the rotor of the synchronous motor, and the rotor of the synchronous governor collectively provide inertial support.
It can be understood that the flywheel rotor with different mass can be replaced, so that the flywheel rotor is suitable for power generation units with different power generation limits, and has strong applicability.
Because the moment of inertia of the rotor system is mechanical inertia, the moment of inertia of a power generation system (for example, a system formed by the synchronous motor and the synchronous camera) is constant, and the available inertia support is limited, in order to solve the problem, in the embodiment, not only the rotor of the synchronous motor and the rotor of the synchronous camera replace the inertia support provided by a generator rotor and a turbine rotor in the conventional fossil fuel power generation, but also the inertia is increased by the flywheel rotor, the inertia time constant is prolonged by increasing the inertia, and the inertia support power is increased by prolonging the inertia time constant; the flywheel rotor also has the function of storing capacity, and can be used as a short-time emergency power supply for primary frequency modulation when necessary.
In one embodiment, the gear set includes: the driving gear is meshed with the driven gear, the driving gear is connected between the synchronous motor and one end of the coupler, and the shaft of the flywheel rotor is connected with the driven gear.
Specifically, the synchronous motor drives the driving gear to rotate; the driving gear rotates to drive the driven gear to rotate, and when the coupler is closed, the driving gear rotates to drive the synchronous governor connected with the other end of the coupler to rotate, so that the synchronous motor and the synchronous governor coaxially move; and the rotation of the driven gear drives the flywheel rotor to rotate.
The embodiment realizes the coaxial connection of the synchronous motor and the synchronous speed regulator through the gear set and the coupling, and connects the flywheel rotor to a power generation system formed by the synchronous motor and the synchronous speed regulator through the gear set, on the basis that inertia support provided by a generator rotor and a turbine rotor when traditional fossil fuel power generation is replaced by a rotor of the synchronous motor and a rotor of the synchronous speed regulator, inertia is increased through the flywheel rotor, an inertia time constant is prolonged through increasing inertia, and inertia support power is increased through prolonging the inertia time constant; the flywheel rotor also has the function of storing energy, and can be used as a short-time emergency power supply for primary frequency modulation when necessary.
As shown in fig. 3, in one embodiment, the coupling is a separable coupling, and the detecting device is further configured to detect a grid instantaneous voltage of the ac grid;
wherein, the detection device includes: the first voltage detection sensor is used for detecting the voltage of the alternating current power grid in real time, for example, detecting the voltage of one end of the grid-connected switch connected with the alternating current power grid in real time, and taking the detected voltage as the power grid instantaneous voltage of the alternating current power grid. The first voltage detection sensor is a sensor for detecting a voltage of the power grid.
The method further comprises the steps of:
s511: acquiring a first voltage deviation value between the instantaneous voltage of the power grid and the rated voltage of the power grid of the alternating current power grid;
the power grid instantaneous voltage is the voltage of the alternating current power grid detected in real time.
The grid rated voltage of the ac grid is the rated voltage of the ac grid. Optionally, the rated voltage of the alternating current power grid is 220V.
Specifically, the power grid instantaneous voltage of the alternating current power grid sent by the detection device is obtained, the latest obtained power grid instantaneous voltage is subtracted by the power grid rated voltage of the alternating current power grid, and the subtracted data is used as a first voltage deviation value.
S512: judging whether the first voltage deviation value is out of a preset first deviation value range or not;
s513: if the synchronous motor is positioned in the synchronous motor, acquiring the instantaneous reactive power of the power grid of the alternating current power grid, and controlling the disconnection of the two ends of the separable coupler so as to disconnect the synchronous motor from the synchronous regulator;
specifically, if not, i.e. the first voltage deviation value is within a preset first deviation value range, this means that the voltage fluctuation range (i.e. the preset first deviation value range) is met, and reactive power regulation is not required.
Specifically, if the first voltage deviation value is located outside the preset first deviation value range, it means that the voltage fluctuation range (i.e., the preset first deviation value range) is not met, and reactive power adjustment is required, so that the power grid instantaneous reactive power of the ac power grid sent by the third party application can be obtained, and the two ends of the separable coupling are controlled to be disconnected so as to disconnect the synchronous motor from the synchronous motor, thereby realizing the independent operation of the synchronous motor and the synchronous motor.
It can be understood that, if the grid-connected power generation system further includes a gear set and a flywheel rotor, when the first voltage deviation value is outside a preset first deviation value range, the synchronous motor and the flywheel rotor form an energy storage flywheel device, and the motor controller takes electricity from the power generation unit to maintain the rotation speed of the synchronous motor.
If the instantaneous reactive power of the power grid is larger than the rated reactive power of the power grid of the alternating current power grid, reducing the exciting current of the rotor of the synchronous regulator;
if the instantaneous reactive power of the power grid is smaller than the rated reactive power of the power grid of the alternating current power grid, increasing the exciting current of the rotor of the synchronous regulator;
and controlling the two ends of the separable coupler to be closed until the first voltage deviation value is within the first deviation value range, so that the synchronous motor can drive the synchronous regulator to synchronously rotate for generating power.
The grid rated reactive power of the ac grid is the rated reactive power of the ac grid.
Specifically, if the instantaneous reactive power of the power grid is greater than the rated reactive power of the ac power grid, this means that the reactive power of the ac power grid is excessive, the voltage will rise to increase the load loss of the user and overload operation, and even cause an accident of the power grid, at this time, the synchronous phase-change machine enters a phase-change machine mode from a generator mode, the exciting current of the rotor of the synchronous phase-change machine is reduced, so that the rotor of the synchronous phase-change machine is underexcited, and the induced electromotive force of the stator of the synchronous phase-change machine will drop, so as to be lower than the voltage of the ac power grid. Because a voltage difference occurs between the voltage of the synchronous regulator and the voltage of the alternating current power grid, the voltage difference can lead the stator winding of the synchronous regulator to generate an inductive reactive current which leads the induced electromotive force by 90 degrees but lags behind the voltage difference by 90 degrees, so that the current flows from the alternating current power grid to the synchronous regulator, and the synchronous regulator is equivalent to an inductive reactive load, namely, the synchronous regulator absorbs the inductive reactive power from the alternating current power grid to reduce the voltage of the alternating current power grid, and the voltage of the alternating current power grid reenters a voltage fluctuation range, thereby regulating the development of the alternating current power grid to a normal running direction.
Specifically, if the instantaneous reactive power of the power grid is smaller than the rated reactive power of the ac power grid, which means that the reactive power of the ac power grid is insufficient, the voltage will drop to cause excessive load current of the user and unable to work normally, and even large-area off-grid accidents will be caused when serious, at this time, the synchronous phase-modulating machine enters a phase-modulating machine mode from a generator mode, the exciting current of the rotor of the synchronous phase-modulating machine is increased to overexcitation the rotor of the synchronous phase-modulating machine, and the induced electromotive force of the stator of the synchronous phase-modulating machine will rise to be higher than the voltage of the ac power grid. Because a voltage difference occurs between the voltage of the synchronous regulator and the voltage of the alternating current power grid, the voltage difference can enable an inductive reactive current to be generated in a stator winding of the synchronous regulator, the inductive reactive current lags behind an induced electromotive force by 90 degrees and lags behind the voltage difference by 90 degrees, so that current flows from the synchronous regulator to the alternating current power grid, the synchronous regulator is equivalent to an inductive reactive power supply, namely, the synchronous regulator provides the inductive reactive power to the alternating current power grid to improve the voltage of the alternating current power grid, and the voltage of the alternating current power grid reenters a voltage fluctuation conforming range, thereby regulating the development of the alternating current power grid to a normal running direction.
Until the first voltage deviation value is within the first deviation value range, the alternating current power grid is enabled to normally operate, two ends of the separable coupler are controlled to be closed, so that the synchronous motor can drive the synchronous phase-regulating machine to synchronously rotate for generating power, and the synchronous phase-regulating machine enters a phase-regulating machine mode generator mode.
It will be appreciated that an additional set of excitation systems is provided to control the excitation current on the rotor coils of the synchronous machine, rather than the synchronous machine itself being able to reduce the excitation current on its rotor.
Compared with the reactive power compensation device of the power electronic type used by the new energy station, the synchronous phase-change power-regulating device of the application can not continuously regulate reactive power compensation and can not cope with the reactive power compensation problem of large power capacity such as power grid section, and the synchronous phase-change power-regulating device of the application has the characteristics of large single-machine capacity and can continuously regulate reactive power, and meanwhile, the working characteristics of the synchronous phase-change power-regulating device are utilized to control the working mode of the synchronous phase-change power-regulating device by switching the on and off of the separable coupler, thereby completing two requirements of active power compensation and reactive power compensation on one device and reducing the use cost of the grid-connected power-generating system.
In one embodiment, the detecting device is further configured to detect a rotor speed of the synchronous motor and a rotor speed of the synchronous motor, and the step of controlling the two ends of the separable coupling to be closed until the first voltage deviation value is within the first deviation value range includes:
until the first voltage deviation value is within the first deviation value range, controlling the synchronous regulator to take electricity from the alternating current power grid to realize idling, and controlling the motor controller to control the synchronous motor to rise;
acquiring a rotational speed deviation value between the rotational speed of the rotor of the synchronous motor and the rotational speed of the rotor of the synchronous regulator;
and controlling the two ends of the separable coupler to be closed until the rotating speed deviation value is within a preset second deviation value range.
The detection device includes: the synchronous motor comprises a first rotating speed detection sensor and a second rotating speed detection sensor, wherein the first rotating speed detection sensor is used for detecting the rotating speed of a rotor of the synchronous motor, and the second rotating speed detection sensor is used for detecting the rotating speed of the rotor of the synchronous motor.
Specifically, until the first voltage deviation value is within the first deviation value range, this means that reactive power adjustment is completed, the rotor of the synchronous regulator resumes a normal excitation state, the synchronous regulator continues to take power from the ac power grid and idle, at this time, the motor controller controls the synchronous motor to increase speed, so that the rotational speeds of the synchronous motor and the synchronous regulator approach the rated ac power supply frequency of the ac power grid (i.e., a preset grid rated frequency), and further, since it is difficult to ensure complete consistency between the rotational speeds of the synchronous motor and the synchronous regulator, the rotational speeds of the synchronous motor and the synchronous regulator are obtained, the rotational speed deviation value is obtained by subtracting the rotational speeds of the synchronous regulator from the rotational speeds of the synchronous motor, and when the rotational speed deviation value is within a preset second deviation value range, this means that the rotational speed deviation value is within an acceptable range until the rotational speeds of the synchronous motor and the synchronous regulator are within the preset second deviation value range, and the two ends of the separable coupling are controlled.
Optionally, the second preset deviation value range is [ -2rpm,2rpm ].
Because the synchronous motor and the synchronous speed regulator need to coaxially move, the rotor rotating speed of the synchronous motor and the rotor rotating speed of the synchronous speed regulator need to be ensured to be consistent as much as possible during connection, in order to avoid too large deviation of the rotor rotating speed of the synchronous motor and the rotor rotating speed of the synchronous speed regulator when the two ends of the separable coupler are closed, the two ends of the separable coupler are controlled to be closed until the rotating speed deviation value is within a preset second deviation value range, and the synchronous motor and the synchronous speed regulator are prevented from being coaxially connected when the rotating speed deviation value is out of the preset second deviation value range, so that the synchronous motor, the synchronous speed regulator and devices between the synchronous motor and the synchronous speed regulator are protected.
As shown in fig. 4, in one embodiment, the grid-connected power generation system includes: the power taking switch is used for detecting the voltage at two ends of the grid-connected switch;
Wherein, the detection device includes: the second voltage detection sensor is connected with one end of the grid-connected switch, and the third voltage detection sensor is connected with the other end of the grid-connected switch, so that the voltage at two ends of the grid-connected switch is detected through the second voltage detection sensor and the third voltage detection sensor.
The method further comprises the steps of:
s61: acquiring a grid-connected instruction;
the grid-connected instruction is an instruction for integrating the electricity generated by the electricity generating unit into an alternating current power grid.
Specifically, the grid-connected instruction input by the user can be obtained, the grid-connected instruction sent by the third party application can be obtained, and the grid-connected instruction triggered by the program file according to the preset condition can be realized. For example, the preset condition is that 8 points per day trigger a grid-connected instruction.
S62: according to the grid-connected instruction, the power taking switch is controlled to be closed, the motor controller takes power from the power generation unit to drive the synchronous motor to rotate, and the synchronous motor can drive the synchronous camera to synchronously rotate for power generation;
specifically, when the grid-connected instruction is acquired, the power taking switch is controlled to be closed in response to the grid-connected instruction, and the motor controller is controlled to take power from the power generation unit to drive the synchronous motor to rotate, so that the synchronous motor can drive the synchronous camera to synchronously rotate to generate power.
S63: acquiring deviation values of voltages at two ends of the grid-connected switch to serve as second voltage deviation values;
specifically, voltages at two ends of the grid-connected switch are obtained, subtraction operation is carried out on the obtained two voltages, and subtracted data are used as second voltage deviation values.
S64: judging whether a preset grid-connected rule is met or not according to the second voltage deviation value;
the preset grid connection rule is a preset grid connection judgment condition.
Optionally, the preset grid-connected rule is that the second voltage deviation value is 0. At this time, if the second voltage deviation value is equal to 0, determining that the second voltage deviation value meets a preset grid-connected rule; if the second voltage deviation value is not equal to 0, determining that the second voltage deviation value does not meet a preset grid-connected rule.
Optionally, the preset grid-connected rule is a preset third deviation value range. At this time, if the second voltage deviation value is within a preset third deviation value range, determining that the second voltage deviation value meets a preset grid-connected rule; if the second voltage deviation value is out of the preset third deviation value range, determining that the second voltage deviation value does not meet the preset grid-connected rule.
S65: and if so, controlling the grid-connected switch to be closed.
Specifically, if the second voltage deviation value meets the preset grid connection rule, the second voltage deviation value means that the electric energy can be connected to the alternating current power grid, so that the grid connection switch is controlled to be closed, and the synchronous motor drives the synchronous camera to synchronously rotate to generate electricity, and the electricity is connected to the alternating current power grid.
It can be understood that if the second voltage deviation value does not meet the preset grid-connection rule, the second voltage deviation value means that the electric energy cannot be connected to the ac power grid, and no operation is performed at this time, so that the grid-connected power generation system continues to charge energy until the second voltage deviation value meets the preset grid-connection rule.
In the embodiment, when the second voltage deviation value judges that the preset grid-connected rule is met, the grid-connected switch is controlled to be closed, so that fluctuation of the alternating current power grid caused by the fact that a power supply which does not meet the preset grid-connected rule is integrated into the alternating current power grid is avoided.
In one embodiment, the grid-connected power generation system further comprises a grid-connected transformer, an input end of the grid-connected transformer is connected with the synchronous phase-regulating device, an output end of the grid-connected transformer is connected with the grid-connected switch and can be connected with the alternating current power grid through the grid-connected switch, and the grid-connected transformer is used for boosting electric energy output by the synchronous phase-regulating device.
According to the embodiment, the grid-connected transformer is used for adjusting the voltage of the electric energy output by the synchronous phase-adjusting machine, so that the grid-connected stability of the grid-connected power generation system is improved, and the adaptability of the grid-connected power generation system is improved.
As shown in fig. 5, a grid-connected power generation system is proposed, which includes: the system controller 9, the motor controller 1, the synchronous motor 2, the coupler 4, the synchronous camera 5, the grid-connected switch S2 and the detection device 8; the motor controller 1 is used for being connected with a power generation unit and taking power from the power generation unit, and the motor controller 1 is connected with the synchronous motor 2 and can drive the synchronous motor 2 to rotate; the synchronous motor 2 is connected with one end of the coupler 4, the other end of the coupler 4 is connected with the synchronous regulator 5, and when the two ends of the coupler 4 are in a connection state, the synchronous motor 2 can drive the synchronous regulator 5 to synchronously rotate for generating electricity; the synchronous regulator 5 is connected with the grid-connected switch S2 and can be connected with an alternating current power grid through the grid-connected switch S2, and the detection device 8 is used for detecting the power grid instantaneous frequency of the alternating current power grid; the system controller 9 comprises a memory storing a computer program and a processor adapted to perform the steps of the control method of the grid-connected power generation system according to any one of the preceding claims when the computer program is executed.
In this embodiment, when the frequency deviation value is not equal to 0, two ends of the coupling are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the ac power grid, so that the combination of the synchronous motor and the synchronous regulator provides sufficient mechanical inertia supporting capability for the ac power grid to avoid impact caused by instantaneous load change at the power grid side, and improve stability of the power grid. When the frequency deviation value is positive and is larger than a preset positive dead zone frequency, the motor controller is controlled to control the synchronous motor to reduce power output, and when the frequency deviation value is negative and smaller than a preset negative dead zone frequency, the motor controller is controlled to control the synchronous motor to increase power output, so that the frequency of an alternating current power grid is quickly responded and adjusted, primary frequency modulation participating in the alternating current power grid is realized, and further the frequency stability of the power grid is autonomously supported. The synchronous motor drives the synchronous phase-adjusting device to synchronously rotate to generate power so as to realize secondary power generation grid connection, so that the influence of harmonic waves of power electronic devices in the new energy station on the alternating current power grid can be isolated, the influence of the alternating current power grid fault on the internal power grid of the new energy station can be isolated, the stability of the power grid is improved, and the safety of the internal power grid of the new energy station is protected.
In one embodiment, the grid-connected power generation system further comprises: a gear set 3 and a flywheel rotor 7, said gear set 3 being connected between the output shaft of said synchronous motor 2 and said flywheel rotor 7.
In one embodiment, the gear set includes: a driving gear 31 and a driven gear 32, the driving gear 31 is meshed with the driven gear 32, the driving gear 31 is connected between the synchronous motor 2 and one end of the coupling 4, and the shaft of the flywheel rotor 7 is connected with the driven gear 32.
In one embodiment, the coupling 4 is a separable coupling, and the detecting device 8 is further configured to detect a grid instantaneous voltage of the ac grid.
In one embodiment, the detection device 8 is further configured to detect a rotor speed of the synchronous motor 2 and a rotor speed of the synchronous motor 5.
In one embodiment, the grid-connected power generation system includes: the power taking switch S1, the power generating unit is a new energy power generating unit, the power taking switch S1 is connected between the power generating unit and the motor controller 1, and the detecting device 8 is further used for detecting voltages at two ends of the grid-connected switch S1.
In one embodiment, the grid-connected power generation system further includes a grid-connected transformer 6, an input end of the grid-connected transformer 6 is connected with the synchronous rectifier 5, an output end of the grid-connected transformer 6 is connected with the grid-connected switch S2 and can be connected with the ac power grid through the grid-connected switch S2, and the grid-connected transformer 6 is used for boosting the electric energy output by the synchronous rectifier 5.
An embodiment of the present application proposes a computer-readable storage medium storing a computer program which, when executed by a processor, implements the steps of the control method of a grid-connected power generation system as described in any one of the above.
In this embodiment, when the frequency deviation value is not equal to 0, two ends of the coupling are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the ac power grid, so that the combination of the synchronous motor and the synchronous regulator provides sufficient mechanical inertia supporting capability for the ac power grid to avoid impact caused by instantaneous load change at the power grid side, and improve stability of the power grid. When the frequency deviation value is positive and is larger than a preset positive dead zone frequency, the motor controller is controlled to control the synchronous motor to reduce power output, and when the frequency deviation value is negative and smaller than a preset negative dead zone frequency, the motor controller is controlled to control the synchronous motor to increase power output, so that the frequency of an alternating current power grid is quickly responded and adjusted, primary frequency modulation participating in the alternating current power grid is realized, and further the frequency stability of the power grid is autonomously supported. The synchronous motor drives the synchronous phase-adjusting device to synchronously rotate to generate power so as to realize secondary power generation grid connection, so that the influence of harmonic waves of power electronic devices in the new energy station on the alternating current power grid can be isolated, the influence of the alternating current power grid fault on the internal power grid of the new energy station can be isolated, the stability of the power grid is improved, and the safety of the internal power grid of the new energy station is protected.
As shown in fig. 6, an embodiment of the present application proposes a system controller of a grid-connected power generation system, including a memory 92 and a processor 91, where the memory 92 stores a computer program that can be run on the processor 91, and when the processor 91 executes the computer program, the steps of the control method of a grid-connected power generation system described in any one of the foregoing are implemented.
In this embodiment, when the frequency deviation value is not equal to 0, two ends of the coupling are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the ac power grid, so that the combination of the synchronous motor and the synchronous regulator provides sufficient mechanical inertia supporting capability for the ac power grid to avoid impact caused by instantaneous load change at the power grid side, and improve stability of the power grid. When the frequency deviation value is positive and is larger than a preset positive dead zone frequency, the motor controller is controlled to control the synchronous motor to reduce power output, and when the frequency deviation value is negative and smaller than a preset negative dead zone frequency, the motor controller is controlled to control the synchronous motor to increase power output, so that the frequency of an alternating current power grid is quickly responded and adjusted, primary frequency modulation participating in the alternating current power grid is realized, and further the frequency stability of the power grid is autonomously supported. The synchronous motor drives the synchronous phase-adjusting device to synchronously rotate to generate power so as to realize secondary power generation grid connection, so that the influence of harmonic waves of power electronic devices in the new energy station on the alternating current power grid can be isolated, the influence of the alternating current power grid fault on the internal power grid of the new energy station can be isolated, the stability of the power grid is improved, and the safety of the internal power grid of the new energy station is protected.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. A control method of a grid-connected power generation system, the method being applied to a grid-connected power generation system, the grid-connected power generation system comprising: the synchronous motor comprises a motor controller, a synchronous motor, a coupler, a synchronous camera, a grid-connected switch and a detection device; the motor controller is used for being connected with the power generation unit and taking power from the power generation unit, is connected with the synchronous motor and can drive the synchronous motor to rotate; the synchronous motor is connected with one end of the coupler, the other end of the coupler is connected with the synchronous speed regulator, and when the two ends of the coupler are in a connection state, the synchronous motor can drive the synchronous speed regulator to synchronously rotate for generating electricity; the synchronous phase regulator is connected with the grid-connected switch and can be connected with an alternating current power grid through the grid-connected switch, and the detection device is used for detecting the power grid instantaneous frequency of the alternating current power grid;
The method comprises the following steps:
acquiring a frequency deviation value between the instantaneous frequency of the power grid and a preset rated frequency of the power grid;
when the frequency deviation value is not equal to 0, two ends of the coupler are in a connection state, and the synchronous motor and the synchronous regulator realize inertia response to the alternating current power grid;
when the frequency deviation value is positive and is larger than a preset forward dead zone frequency, controlling the motor controller to control the synchronous motor to reduce power output;
and when the frequency deviation value is negative and smaller than a preset negative dead frequency, controlling the motor controller to control the synchronous motor to increase power output.
2. The control method of a grid-connected power generation system according to claim 1, characterized in that the grid-connected power generation system further comprises: the gear set is connected between the output shaft of the synchronous motor and the flywheel rotor;
when the frequency deviation value is not equal to 0, two ends of the coupler are in a connection state, and the step of enabling the synchronous motor and the synchronous regulator to realize inertia response to the alternating current power grid comprises the following steps:
generating an inertia response instruction when the frequency deviation value is not equal to 0;
And controlling the frequency of working current of the synchronous motor and the synchronous camera according to the inertia response instruction, and enabling two ends of the coupler to be in a connection state so as to enable the flywheel rotor, the synchronous motor and the synchronous camera to realize inertia response to the alternating current power grid.
3. The control method of a grid-connected power generation system according to claim 2, wherein the gear set includes: the driving gear is meshed with the driven gear, the driving gear is connected between the synchronous motor and one end of the coupler, and the shaft of the flywheel rotor is connected with the driven gear.
4. The control method of a grid-connected power generation system according to claim 1, wherein the coupling is a separable coupling, and the detecting device is further configured to detect a grid instantaneous voltage of the ac grid;
the method further comprises the steps of:
acquiring a first voltage deviation value between the instantaneous voltage of the power grid and the rated voltage of the power grid of the alternating current power grid;
judging whether the first voltage deviation value is out of a preset first deviation value range or not;
If the synchronous motor is positioned in the synchronous motor, acquiring the instantaneous reactive power of the power grid of the alternating current power grid, and controlling the disconnection of the two ends of the separable coupler so as to disconnect the synchronous motor from the synchronous regulator;
if the instantaneous reactive power of the power grid is larger than the rated reactive power of the power grid of the alternating current power grid, reducing the exciting current of the rotor of the synchronous regulator;
if the instantaneous reactive power of the power grid is smaller than the rated reactive power of the power grid of the alternating current power grid, increasing the exciting current of the rotor of the synchronous regulator;
and controlling the two ends of the separable coupler to be closed until the first voltage deviation value is within the first deviation value range, so that the synchronous motor can drive the synchronous regulator to synchronously rotate for generating power.
5. The method according to claim 4, wherein the detecting means is further configured to detect a rotor speed of the synchronous motor and a rotor speed of the synchronous motor, and the step of controlling the separable coupling to close both ends until the first voltage deviation value is within the first deviation value range includes:
Until the first voltage deviation value is within the first deviation value range, controlling the synchronous regulator to take electricity from the alternating current power grid to realize idling, and controlling the motor controller to control the synchronous motor to rise;
acquiring a rotational speed deviation value between the rotational speed of the rotor of the synchronous motor and the rotational speed of the rotor of the synchronous regulator;
and controlling the two ends of the separable coupler to be closed until the rotating speed deviation value is within a preset second deviation value range.
6. The control method of a grid-connected power generation system according to claim 1, characterized in that the grid-connected power generation system comprises: the power taking switch is used for detecting the voltage at two ends of the grid-connected switch;
the method further comprises the steps of:
acquiring a grid-connected instruction;
according to the grid-connected instruction, the power taking switch is controlled to be closed, the motor controller takes power from the power generation unit to drive the synchronous motor to rotate, and the synchronous motor can drive the synchronous camera to synchronously rotate for power generation;
Acquiring deviation values of voltages at two ends of the grid-connected switch to serve as second voltage deviation values;
judging whether a preset grid-connected rule is met or not according to the second voltage deviation value;
and if so, controlling the grid-connected switch to be closed.
7. The method for controlling a grid-connected power generation system according to claim 1, further comprising a grid-connected transformer, wherein an input end of the grid-connected transformer is connected to the synchronous regulator, an output end of the grid-connected transformer is connected to the grid-connected switch and is connectable to the ac grid via the grid-connected switch, and the grid-connected transformer is configured to boost electric energy output by the synchronous regulator.
8. A grid-tied power generation system, comprising: the system comprises a system controller, a motor controller, a synchronous motor, a coupler, a synchronous camera, a grid-connected switch and a detection device; the motor controller is used for being connected with the power generation unit and taking power from the power generation unit, is connected with the synchronous motor and can drive the synchronous motor to rotate; the synchronous motor is connected with one end of the coupler, the other end of the coupler is connected with the synchronous speed regulator, and when the two ends of the coupler are in a connection state, the synchronous motor can drive the synchronous speed regulator to synchronously rotate for generating electricity; the synchronous phase regulator is connected with the grid-connected switch and can be connected with an alternating current power grid through the grid-connected switch, and the detection device is used for detecting the power grid instantaneous frequency of the alternating current power grid; the system controller comprises a memory storing a computer program and a processor adapted to implement the steps of the control method of the grid-connected power generation system as claimed in any one of claims 1 to 7 when the computer program is executed.
9. A computer-readable storage medium storing a computer program, wherein the computer program when executed by a processor implements the steps of the control method of the grid-connected power generation system according to any one of claims 1 to 7.
10. A system controller of a grid-connected power generation system, comprising a memory, a processor, the memory storing a computer program executable on the processor, characterized in that the processor, when executing the computer program, implements the steps of the control method of a grid-connected power generation system as claimed in any one of claims 1 to 7.
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