CN113644688A - Offshore wind power generation system, synchronous control method and offshore power transmission system - Google Patents

Offshore wind power generation system, synchronous control method and offshore power transmission system Download PDF

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Publication number
CN113644688A
CN113644688A CN202110936040.7A CN202110936040A CN113644688A CN 113644688 A CN113644688 A CN 113644688A CN 202110936040 A CN202110936040 A CN 202110936040A CN 113644688 A CN113644688 A CN 113644688A
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China
Prior art keywords
offshore
phase
offshore wind
synchronization signal
wind
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CN202110936040.7A
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Chinese (zh)
Inventor
彭国平
孙文艺
周治国
史奔
张�浩
王红占
李立冬
宋海军
刘会民
徐元龙
白代兵
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Guangdong Anpu Electric Power Technology Co ltd
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Guangdong Anpu Electric Power Technology Co ltd
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Priority to CN202110936040.7A priority Critical patent/CN113644688A/en
Publication of CN113644688A publication Critical patent/CN113644688A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed 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
    • H02J3/002—Flicker reduction, e.g. compensation of flicker introduced by non-linear load
    • 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
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • 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
    • H02J3/388—Islanding, i.e. disconnection of local power supply from the network
    • 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
    • H02J3/40—Synchronising a generator for connection to a network or to another generator
    • 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
    • H02J3/40—Synchronising a generator for connection to a network or to another generator
    • H02J3/42—Synchronising a generator for connection to a network or to another generator with automatic parallel connection when synchronisation is achieved
    • 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
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/76—Power conversion electric or electronic aspects
    • 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
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

An offshore wind power generation system, a synchronous control method and an offshore power transmission system are provided, wherein the offshore wind power generation system comprises: an offshore wind farm comprising a plurality of wind generators; the synchronous signal receiving modules are connected with the local control units of the wind driven generators in a one-to-one correspondence mode, and are all used for receiving wireless synchronous signals and converting the wireless synchronous signals into phase calibration trigger signals which are used for prompting the wind driven generators to carry out phase adjustment; the wireless synchronization signal is transmitted by at least one of the Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C. According to the invention, the wireless synchronization signal sent by the system is received, and the phase synchronization signal of the power grid side voltage is not required to be acquired by using a phase-locked loop technology, so that the wind driven generator is effectively regulated.

Description

Offshore wind power generation system, synchronous control method and offshore power transmission system
Technical Field
The invention belongs to the field of direct current power transmission, and particularly relates to an offshore wind power generation system, a synchronous control method and an offshore power transmission system.
Background
With the development of the offshore wind power industry, the problem of large-scale and long-distance offshore wind power grid connection stability is more and more concerned. The offshore wind power plant is far away from the shore power grid and the connecting submarine cable is long, so the power grid impedance is high. The mutual coupling of the fan system and the power grid impedance, harmonic waves generated by a fan converter and the coupling effect between fan control systems can cause the stability of the system to be reduced, and further oscillation and even instability are generated.
In order to solve this problem, the conventional method uses a phase-locked loop technique to perform phase locking, so as to achieve the purpose of stable control. However, in actual work, since the system impedance of the power grid is large, the offshore wind farm belongs to a weak power grid, and the phase-locked loop technology cannot ensure that the wind turbine converter can effectively obtain a power grid phase synchronization signal, the problem of system oscillation still exists.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides an offshore wind power generation system, which solves the problem of system oscillation caused by difficulty in obtaining a power grid phase synchronization signal in an offshore wind farm. The invention also provides an offshore wind turbine synchronous control method and an offshore power transmission system.
An offshore wind power generation system according to an embodiment of the first aspect of the invention, comprising the steps of:
the offshore wind power generation field comprises a plurality of wind power generators, and the wind power generators are commonly used for transmitting power to a power transformation system;
the system comprises a plurality of synchronous signal receiving modules, a plurality of wind driven generator local control units and a plurality of synchronous signal receiving modules, wherein the synchronous signal receiving modules are connected with the local control units of the wind driven generators in a one-to-one correspondence manner, and are all used for receiving wireless synchronous signals and converting the wireless synchronous signals into phase calibration trigger signals, and the phase calibration trigger signals are used for prompting the wind driven generators to carry out phase adjustment; the wireless synchronization signal is sent by at least one of Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C.
According to the embodiment of the invention, the offshore wind power generation system has at least the following technical effects: the synchronous signal receiving module can receive the wireless synchronous signal and convert the wireless synchronous signal into the phase calibration trigger signal, so that the phase calibration trigger signal can be used for phase adjustment, a phase-locked loop technology is not needed to obtain the power grid phase synchronous signal of the offshore power grid side voltage, and the problem that the power grid phase synchronous signal cannot be obtained due to the adoption of the phase-locked loop technology is completely avoided. Compared with the traditional phase-locked loop technology, the offshore wind power generation system provided by the embodiment of the invention has the advantages of higher stability and simpler control process, can effectively solve the problem of fan system oscillation, and is suitable for industrial popularization.
According to some embodiments of the present invention, each local control unit of the wind turbine is embedded with an internal time keeping unit, and each internal time keeping unit is configured to provide local time information for the corresponding local control unit.
According to the embodiment of the second aspect of the invention, the offshore wind turbine synchronous control method comprises the following steps:
acquiring a phase calibration trigger signal, wherein the phase calibration trigger signal is obtained by converting a wireless synchronization signal by a synchronization signal receiving module, and the wireless synchronization signal is sent to the synchronization signal receiving module by at least one of Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C;
and adjusting the output phase of the output side of the wind driven generator according to the phase calibration trigger signal.
The offshore wind turbine synchronous control method provided by the embodiment of the invention at least has the following technical effects: the wireless synchronization signal is obtained to generate the phase calibration trigger signal, and the phase-locked loop technology is not needed to obtain the power grid phase synchronization signal of the power grid side voltage, so that the problem that the power grid phase synchronization signal cannot be obtained due to the adoption of the phase-locked loop technology can be completely avoided. Compared with the traditional phase-locked loop technology, the offshore wind turbine synchronous control method provided by the embodiment of the invention has the advantages of higher stability and simpler control process, can effectively solve the problem of wind turbine system oscillation, and is suitable for industrial popularization.
According to some embodiments of the present invention, the above method for synchronously controlling an offshore wind turbine further comprises the following steps:
and if the synchronous signal receiving module fails, determining the phase calibration trigger signal by using local time information, wherein the local time information is generated by the internal time keeping unit, and the internal time keeping unit is internally arranged in a local control unit of the wind driven generator.
An offshore power transmission system according to an embodiment of the third aspect of the invention, comprising:
an offshore wind power generation system as described above;
and the power transformation system is connected with the output end of the offshore wind farm and is used for transforming the voltage output by the offshore wind farm.
According to the embodiment of the invention, the offshore power transmission system has the following technical effects: the offshore wind power generation system can utilize the wireless synchronous signal to synchronously adjust the plurality of wind power generators in the offshore wind power generation field, and the power transformation system can ensure that the electric energy generated by the offshore wind power generation field cannot be directly input into a power grid, so that the voltage regulated and output by utilizing the wireless synchronous signal cannot conflict with the voltage of the power grid, and the normal operation of the offshore wind power generation system is ensured.
According to some embodiments of the invention, the power transformation system comprises:
the input end of the offshore converter station is connected with the output end of the offshore wind farm and is used for converting the alternating current output by the offshore wind farm into direct current;
and the input end of the onshore converter station is connected with the output end of the offshore converter station and is used for converting the direct current output by the offshore converter station into alternating current.
According to some embodiments of the invention, the power transformation system comprises a substation for converting and inputting alternating current output by the offshore wind farm to an isolated grid.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a system block diagram of an offshore wind power generation system of an embodiment of the present invention;
FIG. 2 is a system block diagram of an offshore power transmission system provided by an embodiment of the invention;
FIG. 3 is a system block diagram of an offshore power transmission system provided by another embodiment of the present invention;
FIG. 4 is a schematic diagram of an offshore wind turbine synchronization control method according to an embodiment of the invention.
Reference numerals;
an offshore wind farm 100, a wind turbine 110,
A synchronous signal receiving module 200,
A power transformation system 300, an offshore converter station 310, an onshore converter station 320, a substation 330,
And (4) isolated network 400.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description of the present invention, if there are first, second, third, fourth, etc. described only for the purpose of distinguishing technical features, they are not to be interpreted as indicating or implying relative importance or implying number of indicated technical features or implying precedence of indicated technical features.
In the description of the present invention, unless otherwise explicitly defined, terms such as arrangement, connection and the like should be broadly construed, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the detailed contents of the technical solutions.
An offshore wind power generation system according to an embodiment of the first aspect of the invention is described according to fig. 1 to 4.
According to the embodiment of the invention, the offshore wind power generation system comprises: an offshore wind farm 100, a plurality of synchronization signal receiving modules 200, a plurality of internal time keeping units.
An offshore wind farm 100 comprising a plurality of wind turbines 110, the plurality of wind turbines 110 being commonly used for transmitting power to a power transformation system 300;
the plurality of synchronous signal receiving modules 200 are connected with the local control units of the plurality of wind power generators 110 in a one-to-one correspondence manner, the plurality of synchronous signal receiving modules 200 are all used for wirelessly receiving synchronous signals and converting the wireless synchronous signals into phase calibration trigger signals, and the phase calibration trigger signals are used for prompting the wind power generators to perform phase adjustment; the wireless synchronization signal is transmitted by at least one of the Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C.
Referring to fig. 1 to 4, the systems such as beidou, GPS, galileo, GLONASS, GNSS/Loran-C, and the like may wirelessly transmit the synchronization signal in a broadcast manner, and in an open ocean environment, the distance difference between the wind power generators 110 in the same offshore wind power plant 100 may be negligible compared with the transmission speed of the electromagnetic wave, so that it is sufficient to ensure that each synchronization signal receiving module 200 can synchronously receive the same wireless synchronization signal, and the synchronization signal receiving module 200 can convert the wireless synchronization signal into a phase calibration trigger signal in real time and transmit the phase calibration trigger signal to the local control unit of the wind power generator 110. Once the local control unit receives the phase calibration trigger signal and determines that the phase calibration trigger signal is valid, it may determine the output phase that the wind turbine 110 should correspond to in this state. It should be noted here that after receiving the same wireless synchronization signal, the multiple wind turbines 110 do not adjust the output phases of all the wind turbines 110 to be consistent, but adjust the output phases according to the actual engineering situation, for example, factors such as the transmission distance need to be considered, but these factors are basically fixed, so after determining the wireless synchronization signal, the output phase corresponding to each wind turbine 110 can be determined, and thus, when all the rated wind turbine output voltages are converged, the same frequency and the same phase can be achieved.
The wireless synchronization signal may be understood as a standard clock signal of the system, and the synchronization signal receiving module 200 generates a waveform with a period change, i.e., a phase calibration trigger signal, upon receiving the standard clock signal, and then performs synchronization control through the phase calibration trigger signal. Taking the phase calibration trigger signal as a square wave with a frequency of 1Hz as an example for specific description, here, a falling edge is taken as a trigger condition, when the moment that the square wave signal output by the synchronization signal receiving module 200 jumps from a high level to a low level, i.e. representing that 1 second passes, the wind turbine generator 110 should finish outputting fifty waveforms (the power grid is 50Hz), and should be in a phase 0 or an initial phase at this moment, if the wind turbine generator 110 is not in the phase, adjustment needs to be performed, and then, each time the square wave signal is in the falling edge, an output phase can be determined, so that adjustment of the output phase of the wind turbine generator 110 is achieved, and finally, synchronous control of all wind turbine generators 110 in the whole offshore wind turbine farm 100 is achieved.
According to the offshore wind power generation system provided by the embodiment of the invention, the synchronization signal receiving module 200 can receive the wireless synchronization signal and convert the wireless synchronization signal into the phase calibration trigger signal, so that the phase calibration trigger signal can be used for phase adjustment, a phase-locked loop technology is not required to obtain a power grid phase synchronization signal of the offshore power grid side voltage, and the problem that the power grid phase synchronization signal cannot be obtained due to the adoption of the phase-locked loop technology is completely avoided. Compared with the traditional phase-locked loop technology, the offshore wind power generation system provided by the embodiment of the invention has the advantages of higher stability and simpler control process, can effectively solve the problem of fan system oscillation, and is suitable for industrial popularization.
In some embodiments of the present invention, the synchronization signal receiving module 200 may adopt a k801 type GPS beidou dual-mode clock module of shanghai kui jieli electric limited company to achieve the purpose of outputting an accurate phase calibration trigger signal.
In some embodiments of the present invention, each local control unit of wind turbine 110 has an internal time keeping unit built therein, and each internal time keeping unit is configured to provide local time information for the corresponding local control unit. In actual work, it may be that the synchronization signal receiving module 200 cannot acquire the wireless synchronization signal due to some faults, at this time, the phase calibration trigger signal may be generated by assisting with local time information provided by the connected internal timekeeping unit, and an alarm signal may be sent to the monitoring terminal when the wireless synchronization signal cannot be received for a certain duration, so as to remove the fault in time. In addition, in order to avoid an error between the local time information provided by the internal time keeping unit and the standard clock signal corresponding to the wireless synchronization signal, the local time information provided by the internal time keeping unit is corrected every time the wireless synchronization signal is received, so that an accumulated error caused by too long working time is eliminated. It should be noted that the internal time keeping unit compensates the characteristics of the crystal oscillator or the atomic clock according to the stored parameters, so as to achieve the purpose of continuously providing high-reliability local time information.
According to the embodiment of the second aspect of the invention, the offshore wind turbine synchronous control method comprises the following steps:
acquiring a phase calibration trigger signal, wherein the phase calibration trigger signal is obtained by converting a wireless synchronization signal by a synchronization signal receiving module, and the wireless synchronization signal is sent to the synchronization signal receiving module by at least one of Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C;
and adjusting the output phase of the output side of the wind driven generator 110 according to the phase calibration trigger signal.
Referring to fig. 1 to 4, the systems such as beidou, GPS, galileo, GLONASS, GNSS/Loran-C, and the like may wirelessly transmit the synchronization signal in a broadcast manner, and in an open ocean environment, the distance difference between the wind power generators 110 in the same offshore wind power plant 100 may be negligible compared with the transmission speed of the electromagnetic wave, so that it is sufficient to ensure that each synchronization signal receiving module 200 can synchronously receive the same wireless synchronization signal, and the synchronization signal receiving module 200 can convert the wireless synchronization signal into a phase calibration trigger signal in real time and transmit the phase calibration trigger signal to the local control unit of the wind power generator 110. Once the local control unit receives the phase calibration trigger signal and determines that the phase calibration trigger signal is valid, it may determine the output phase that the wind turbine 110 should correspond to in this state. It should be noted here that after receiving the same wireless synchronization signal, the multiple wind turbines 110 do not adjust the output phases of all the wind turbines 110 to be consistent, but adjust the output phases according to the actual engineering situation, for example, factors such as the transmission distance need to be considered, but these factors are basically fixed, so after determining the wireless synchronization signal, the output phase corresponding to each wind turbine 110 can be determined, and thus, when all the rated wind turbine output voltages are converged, the same frequency and the same phase can be achieved.
The wireless synchronization signal may be understood as a standard clock signal of the system, and the synchronization signal receiving module 200 generates a waveform with a period change, i.e., a phase calibration trigger signal, upon receiving the standard clock signal, and then performs synchronization control through the phase calibration trigger signal. Taking the phase calibration trigger signal as a square wave with a frequency of 1Hz as an example for specific description, here, a falling edge is taken as a trigger condition, when the moment that the square wave signal output by the synchronization signal receiving module 200 jumps from a high level to a low level, i.e. representing that 1 second passes, the wind turbine generator 110 should finish outputting fifty waveforms (the power grid is 50Hz), and should be in a phase 0 or an initial phase at this moment, if the wind turbine generator 110 is not in the phase, adjustment needs to be performed, and then, each time the square wave signal is in the falling edge, an output phase can be determined, so that adjustment of the output phase of the wind turbine generator 110 is achieved, and finally, synchronous control of all wind turbine generators 110 in the whole offshore wind turbine farm 100 is achieved.
Here, when the converter of the wind turbine 110 is controlled, the 0 phase or the initial phase Φ is not directly usedgridControl is carried out, and three-phase current i at the output side of the wind driven generator 110 is obtained at the same timeabcAfter use, use iabcAnd phigridAnd a modulation wave is constructed to realize the regulation of the converter, so that the aim of regulating the output phase, frequency and amplitude of the converter of the wind driven generator 110 is fulfilled.
According to the offshore wind turbine synchronization control method, the wireless synchronization signal is obtained to generate the phase calibration trigger signal, the phase-locked loop technology is not needed to obtain the power grid phase synchronization signal of the power grid side voltage, and the problem that the power grid phase synchronization signal cannot be obtained due to the adoption of the phase-locked loop technology can be completely avoided. Compared with the traditional phase-locked loop technology, the offshore wind turbine synchronous control method provided by the embodiment of the invention has the advantages of higher stability and simpler control process, can effectively solve the problem of wind turbine system oscillation, and is suitable for industrial popularization.
In some embodiments of the present invention, the above method for synchronously controlling an offshore wind turbine further includes the following steps:
if the synchronization signal receiving module fails, the phase calibration trigger signal is determined using local time information, which is generated by an internal time keeping unit built in the local control unit of the wind turbine 110.
In actual work, it may be that the synchronization signal receiving module 200 cannot acquire the wireless synchronization signal due to some faults, at this time, the phase calibration trigger signal may be generated by assisting with local time information provided by the connected internal timekeeping unit, and an alarm signal may be sent to the monitoring terminal when the wireless synchronization signal cannot be received for a certain duration, so as to remove the fault in time. In addition, in order to avoid an error between the local time information provided by the internal time keeping unit and the standard clock signal corresponding to the wireless synchronization signal, the local time information provided by the internal time keeping unit is corrected every time the wireless synchronization signal is received, so that an accumulated error caused by too long working time is eliminated. It should be noted that the internal time keeping unit compensates the characteristics of the crystal oscillator or the atomic clock according to the stored parameters, so as to achieve the purpose of continuously providing high-reliability local time information.
An offshore power transmission system according to an embodiment of the third aspect of the invention, comprising:
an offshore wind power generation system as described above;
and the power transformation system 300 is connected with the output end of the offshore wind farm 100 and is used for transforming the voltage output by the offshore wind farm 100.
Referring to fig. 1 to 4, the offshore wind power generation system outputs the ac power, but because the rated phase used in adjusting the ac power is calculated by using the synchronization signal, rather than directly using the voltage on the grid side through the phase-locked loop technology, the rated phase cannot reflect the frequency and phase on the grid side, and if the offshore wind power generation system is directly put into use on the grid side, once the grid side itself is connected with another power supply system, the grid connection may be problematic due to the inconsistent phases between the offshore wind power generation system and the other power supply system, thereby causing an accident. For this, the power transformation system 300 is connected between the output end of the offshore wind farm 100 and the power grid side, the offshore wind farm 100 can be separated from the power grid side through the power transformation system 300, and if the power grid side does not have other power supply systems for power supply, the offshore wind farm 100 can be directly output after being subjected to voltage transformation conversion through the power transformation system 300; if the power grid side is connected with other power supply systems, the phase, amplitude and frequency can be adjusted through the power transformation system 300, and then grid connection is carried out.
According to the offshore power transmission system provided by the embodiment of the invention, the offshore wind power generation system can utilize the wireless synchronous signal to synchronously adjust the plurality of wind driven generators 110 in the offshore wind power generation field 100, and the power transformation system 300 can ensure that the electric energy generated by the offshore wind power generation field 100 is not directly input into a power grid, so that the voltage regulated and output by the synchronous signal is not in conflict with the voltage of the power grid, and the normal operation of the offshore wind power generation system is ensured.
In some embodiments of the present invention, referring to fig. 2, a power transformation system 300 includes: an offshore converter station 310, an onshore converter station 320. An offshore converter station 310, the input end of which is connected to the output end of the offshore wind farm 100, for converting the ac power output by the offshore wind farm 100 into dc power; an onshore converter station 320 having an input connected to the output of the offshore converter station 310 for converting the dc power output by the offshore converter station 310 to ac power. The electricity generated by the offshore wind farm 100 is connected to the offshore converter station 310 through an offshore alternating current feeder line, is converted into direct current by the offshore converter station 310 and then remotely transmitted to the onshore converter station 320 through an offshore transmission link, is further converted into alternating current by the onshore converter station 320 and then is merged into a power grid for use, and can be inverted by using information such as frequency, phase, amplitude and the like of the power grid side in the process of converting the direct current into the alternating current so as to ensure that the onshore converter station 320 is successfully connected to the grid. In the whole process, the offshore wind farm 100 does not need to be directly connected with the power grid side, so that the normal execution of the offshore wind power generation system of the embodiment of the invention is ensured.
A brief description of the specific construction of the offshore converter station 310 and the onshore converter station 320 is given here.
The offshore converter station 310 is composed of a transformer, a converter valve, a smoothing reactor and a high-voltage switch which are connected in sequence, and the converter valve can realize the conversion from alternating current to direct current. The primary side of the transformer is used for connecting to the offshore wind farm 100, and the secondary side is connected to the input end of the converter valve.
The converter valves may take a variety of forms. In some embodiments of the invention, the converter valve is in an uncontrolled rectifier diode valve configuration, the diode valve is in a three-phase bridge six-pulse rectifier configuration, and each rectifier bridge arm comprises a plurality of diode devices connected in series in sequence. In some embodiments of the present invention, the converter valve adopts an MMC converter valve structure, the MMC converter valve includes 6 bridge arms, each bridge arm is formed by sequentially connecting a plurality of power modules and a bridge arm reactor in series, and the power modules may adopt a half-bridge structure, a full-bridge structure, or a half-bridge and full-bridge mixed connection structure. In some embodiments of the invention, the converter valve is in the form of a thyristor converter valve, the thyristor converter valve is in a three-phase bridge configuration, each bridge arm comprises a plurality of thyristor devices connected in series in sequence, and the thyristor converter valve is connected to the secondary side of the transformer via a connecting reactor.
The shore-based converter station 320 is composed of a converter valve, a transformer and a high-voltage switch which are connected in sequence, and the converter valve can also have various structures including but not limited to an MMC converter valve structure and a thyristor converter valve structure.
The marine transmission link consists of a high-voltage direct-current submarine cable, a signal optical fiber and the like.
In some embodiments of the present invention, the power transformation system 300 comprises a substation 330, and the substation 330 is used for isolating and inputting the alternating current output by the offshore wind farm 100 to the isolated grid 400. The offshore power transmission system comprises an offshore transmission link, a transformer substation 330, an isolated grid 400 and the like. The alternating current output by the offshore wind farm 100 is connected to the substation 330 via an offshore transmission link, and the substation 330 converts the alternating current into a standard voltage and then sends the standard voltage to the isolated grid 400 for power supply. In this scenario, the isolated network 400 is composed of industrial loads, civil loads, power electronic devices, and the like, and therefore, the substation 330 does not need to provide frequency modulation and phase modulation capabilities, and therefore, the substation 330 only includes a transformer, a high-voltage switch, and an auxiliary power distribution device. When the isolated grid 400 needs to be connected to the grid, the isolated grid can also be connected with a large power grid through converter valves at two ends in a back-to-back direct current mode, and asynchronous interconnection with the large power grid is achieved.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean 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 invention. 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.
Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to the embodiments, and those skilled in the art will understand that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (7)

1. An offshore wind power generation system, comprising:
the offshore wind power generation field comprises a plurality of wind power generators, and the wind power generators are commonly used for transmitting power to a power transformation system;
the system comprises a plurality of synchronous signal receiving modules, a plurality of wind driven generator local control units and a plurality of synchronous signal receiving modules, wherein the synchronous signal receiving modules are connected with the local control units of the wind driven generators in a one-to-one correspondence manner, and are all used for receiving wireless synchronous signals and converting the wireless synchronous signals into phase calibration trigger signals, and the phase calibration trigger signals are used for prompting the wind driven generators to carry out phase adjustment; the wireless synchronization signal is sent by at least one of Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C.
2. The offshore wind power generation system of claim 1, wherein each local control unit of the wind turbine has an internal time keeping unit built therein, and each internal time keeping unit is configured to provide local time information to the corresponding local control unit.
3. A synchronous control method for an offshore wind turbine is applied to a wind driven generator and is characterized by comprising the following steps:
acquiring a phase calibration trigger signal, wherein the phase calibration trigger signal is obtained by converting a wireless synchronization signal by a synchronization signal receiving module, and the wireless synchronization signal is sent to the synchronization signal receiving module by at least one of Beidou, GPS, Galileo, GLONASS and GNSS/Loran-C;
and adjusting the output phase of the output side of the wind driven generator according to the phase calibration trigger signal.
4. The offshore wind turbine synchronous control method according to claim 3, further comprising the steps of:
and if the synchronous signal receiving module fails, determining the phase calibration trigger signal by using local time information, wherein the local time information is generated by the internal time keeping unit, and the internal time keeping unit is internally arranged in a local control unit of the wind driven generator.
5. An offshore power transmission system, comprising:
an offshore wind power generation system as claimed in any one of claims 1 to 2;
and the power transformation system is connected with the output end of the offshore wind farm and is used for converting the voltage output by the offshore wind farm.
6. An offshore power transmission system according to claim 5, characterized in that the power transformation system comprises:
the input end of the offshore converter station is connected with the output end of the offshore wind farm and is used for converting the alternating current output by the offshore wind farm into direct current;
and the input end of the onshore converter station is connected with the output end of the offshore converter station and is used for converting the direct current output by the offshore converter station into alternating current.
7. An offshore power transmission system according to claim 5, characterized in that the power transformation system comprises a substation for converting and inputting alternating current output by the offshore wind farm to an isolated grid.
CN202110936040.7A 2021-08-16 2021-08-16 Offshore wind power generation system, synchronous control method and offshore power transmission system Pending CN113644688A (en)

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