CN115528703A - Penetration control method, device and system for flexible direct current output voltage of offshore wind power - Google Patents
Penetration control method, device and system for flexible direct current output voltage of offshore wind power Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
- H02J3/241—The oscillation concerning frequency
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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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
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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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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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
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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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
- H02J2003/365—Reducing harmonics or oscillations in HVDC
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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
- 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
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
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Abstract
The invention discloses a penetration control method, a penetration control device and a penetration control system for flexible direct current output voltage of offshore wind power, wherein the penetration control method comprises the following steps: collecting real-time voltage signals of an alternating current side of a land station; the collected voltage signals are processed to generate modulation signals, and the alternating current side of an AC/DC converter of the offshore station is controlled through the modulation signals, so that the voltage of the offshore wind farm participates in power grid frequency modulation. After the control method is adopted, the direct-current power transmission system presents a transparent characteristic in the grid connection from the offshore wind farm to the onshore alternating-current power grid. When the system is in normal operation, the offshore wind farm can normally participate in frequency modulation of the power grid as if the offshore wind farm is directly incorporated into an alternating current power grid. During the fault period of the onshore alternating current power grid, the offshore wind farm can feel voltage drop if directly connected to the power grid, and enters a low voltage ride through function according to the voltage drop range, so that the problem that wind power is accumulated in a direct current transmission system is fundamentally avoided.
Description
Technical Field
The invention belongs to the technical field of new energy and energy conservation, and particularly relates to a penetration control method, device and system for flexible direct current output voltage of offshore wind power.
Background
Compared with onshore wind power, offshore wind power has the unique advantages of stable wind energy resources, no land occupation, good digestion conditions and the like, and meanwhile, offshore wind power is closer to a load center and becomes the key point of wind power development in recent years. At present, the grid connection mode of offshore wind power transmission is mainly divided into two categories of high-voltage alternating current transmission and high-voltage direct current transmission, wherein the high-voltage direct current transmission adopts a flexible direct current transmission technology based on a voltage source converter. Compared with alternating current transmission, flexible direct current transmission has the advantages of large transmission capacity, long transmission distance, no reactive power and power angle stability problems and the like, and is the best choice for intensively transmitting the far-sea wind power in the future.
In the existing document 1 (study on control strategy of offshore wind power through grid connection of flexible direct current transmission system, li yujun, zhejiang university), it is mentioned that in an offshore wind power flexible direct transmission system, a land station generally performs constant direct current voltage control and constant reactive power control to provide stable direct current voltage and reactive power exchange between a control system and a power grid; the offshore station controls the amplitude and the phase of the fixed alternating voltage based on the direct voltage provided by the onshore station to establish alternating current collecting voltage for the offshore wind farm; each fan in the offshore wind farm is connected to the offshore station through alternating current collection, and the power of each fan is sent out. The dc transmission system provides only the collecting and sending channels, the sending power of which is completely determined by the power sent by the wind farm.
In the current technical scheme, the control functions of the offshore station and the onshore station are relatively independent, and the direct current voltage reference value and the reactive power reference value of the onshore station and the alternating current voltage amplitude value and the phase reference value of the offshore station can be given independently. Due to the isolation of the direct current link, asynchronous networking of alternating current systems on two sides is achieved, and the alternating current voltage of the wind power plant controlled by the offshore station is not affected by the operation condition of an alternating current power grid of the onshore station. The stability and the flexible power control capability of the offshore wind power grid connection are improved.
However, the above control scheme completely blocks the connection between the wind farm and the onshore ac grid, and has the following problems:
1. the fan can not participate in the voltage regulation and peak regulation of the power grid by sensing the voltage and the frequency of the alternating current power grid, and the power grid loses the frequency and voltage regulation capacity of the wind power plant.
2. The fan cannot timely know the conditions of limiting power output such as low voltage fault of an alternating current power grid, so that when the onshore alternating current power grid is in fault, the offshore wind power plant still generates power normally, a large amount of wind power accumulates in a direct current power transmission system to cause the rise of a direct current voltage pump, and the operation safety of the system is damaged.
In view of the above problem 2, there is a technical solution to perform fault ride-through of the onshore power grid by configuring a dc energy consumption device (prior document 2, cn111162559a), setting dc voltage sensing (prior document 3, cn113972681a), setting ac fault sensing and offshore side step-up and step-down (prior document 4, cn112421669a), but all of them are to add a fault ride-through processing mechanism (including required strategies, devices, controllers, etc.) on the basis of an original control mode, rather than improve an original framework from a system overall control mode. Meanwhile, these added fault-ride-through handling mechanisms only work during the ac-side fault of the ground station, and cannot provide a solution to the above-mentioned category 1 problem.
Disclosure of Invention
Aiming at the problems, the invention provides a penetration control method, a penetration control device and a penetration control system for flexible direct current output voltage of offshore wind power, and provides a solution to the problems in the category 1.
A penetration control method for flexible direct current output voltage of offshore wind power comprises the following steps: collecting real-time voltage signals of an alternating current side of a land station; the collected voltage signals are processed to generate modulation signals, and the alternating current side of an AC/DC converter of the offshore station is controlled through the modulation signals, so that the voltage of the offshore wind farm participates in frequency modulation of a power grid.
Further, a modulation signal is generated to control the alternating current side of the AC/DC converter, so that the voltage of the offshore wind farm participates in the frequency modulation of the power grid as follows:
and the AC/DC converter generates trigger pulses of all switching devices in the AC/DC converter according to the modulation waveform, and drives all the switching devices to trigger according to the pulse sequence, so that a voltage waveform which is consistent with the waveform of the land station alternating current power grid and the amplitude of which is scaled according to a set proportion is formed on the alternating current side of the offshore station.
Further, the method also comprises the following steps:
when frequency deviation occurs in an alternating current power grid of the onshore station, a corresponding modulation signal is generated to control an AC/DC converter of the offshore station, so that an offshore wind farm automatically participates in power grid frequency modulation.
Furthermore, when the high-voltage fault occurs in the alternating current power grid of the onshore station, a corresponding modulation signal is generated to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing the high-voltage ride-through function.
Furthermore, when the alternating current power grid of the onshore station has a low-voltage fault, a corresponding modulation signal is generated to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a low-voltage ride-through function.
Further, the real-time voltage signal on the AC side of the ground station is a voltage waveform represented in a per unit.
Further, the modulation signal is a modulation waveform expressed per unit.
Further, the collected voltage signal is processed, including shaping, time delay compensation and three-phase balance processing after communication.
The invention also provides a penetration control device for the offshore wind power flexible direct current output voltage, which comprises a voltage acquisition device arranged on a land station, a cross-sea communication device and a voltage modulation control device arranged on the offshore station;
the voltage acquisition device is used for acquiring a real-time voltage signal at the AC side of the onshore station and then sending the real-time voltage signal to the voltage modulation control device through the cross-sea communication device;
the voltage modulation control device is used for processing the acquired voltage signal to generate a modulation signal, and controlling the alternating current side of the AC/DC converter of the offshore station through the modulation signal to enable the voltage of the offshore wind farm to participate in power grid frequency modulation.
Further, the voltage modulation control device is specifically configured to:
and the AC/DC converter generates trigger pulses of all switching devices in the AC/DC converter according to the modulation waveform and drives all the switching devices to trigger according to the pulse sequence, so that a voltage waveform which is consistent with the waveform of the land station alternating current power grid and the amplitude of which is scaled according to a set proportion is formed at the alternating current side of the offshore station.
Further, the voltage modulation control device is specifically configured to:
when frequency deviation occurs in an alternating current power grid of the onshore station, a corresponding modulation signal is generated to control an AC/DC converter of the offshore station, so that an offshore wind farm automatically participates in power grid frequency modulation;
when a high-voltage fault occurs in an alternating current power grid of the onshore station, generating a corresponding modulation signal to control an AC/DC converter of the offshore station, so that an offshore wind farm automatically participates in executing a high-voltage ride-through function;
when the alternating current power grid of the onshore station has a low-voltage fault, a corresponding modulation signal is generated to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a low-voltage ride-through function.
The invention also provides an offshore wind power flexible direct current transmission voltage penetration control system which comprises the offshore wind power flexible direct current transmission voltage penetration control device and an offshore wind power flexible direct current transmission system, wherein the offshore wind power flexible direct current transmission system comprises a land station, an offshore station and an offshore wind farm.
The invention has the beneficial effects that: after the offshore wind power flexible direct current sending voltage penetration control method is adopted, the direct current transmission system has a transparent characteristic in the grid connection of an offshore wind power plant to a land alternating current power grid. When the system is in normal operation, the offshore wind farm can normally participate in the frequency modulation of the power grid according to the sensed grid-connected voltage frequency and phase characteristics as if the offshore wind farm is directly connected to the alternating current power grid. During the fault period of the onshore alternating current power grid, the offshore wind farm can feel voltage drop if directly connected to the power grid, and enters a low voltage ride through function according to the voltage drop range, so that the problem that wind power is accumulated in a direct current transmission system is fundamentally avoided.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 shows a schematic structural diagram of an offshore wind power soft and direct delivery system according to the prior art;
FIG. 2 shows a schematic structural diagram of an offshore wind power flexible DC output voltage penetration control system according to an embodiment of the invention;
fig. 3 shows a flow diagram of a method for controlling penetration of a flexible direct current output voltage of offshore wind power according to an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in this application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances in order to facilitate the description of the embodiments of the application herein. In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings.
The invention provides a penetration control method, a device and a system for flexible Direct Current (DC) output voltage of offshore wind power, which realize penetration of AC voltage information by mapping AC voltage constant transformation ratio of a land station to the offshore station, and a fan of an offshore wind farm is normally configured with functions of frequency modulation, high voltage penetration, low voltage penetration and the like in the same way that a land wind farm is directly merged into an AC power grid.
Referring to fig. 1, fig. 1 shows a schematic structural diagram of an offshore wind power soft and direct delivery system according to the prior art.
In order to facilitate understanding of the embodiment of the application, the offshore wind power flexible direct-output system is briefly introduced as follows:
the offshore wind power flexible direct-transmission system comprises an alternating current power grid, an onshore station, an offshore wind farm and an offshore station, wherein the onshore station comprises a DC/AC converter and a first transformer, and the offshore station comprises an AC/DC converter, a second transformer and an offshore wind farm.
Specifically, an input end of an alternating current power grid is connected with one end of a first transformer, the other end of the first transformer is connected with an alternating current side of a DC/AC converter, a direct current side of the DC/AC converter is connected with a direct current side of the AC/DC converter through a high-voltage direct-current submarine cable, the alternating current side of the AC/DC converter is connected with one end of a second transformer, and the other end of the second transformer is connected with an output end of an offshore wind farm.
The offshore wind farm comprises at least one fan and a fan alternating current collection line, and the fan is connected with an alternating current collection bus of the second transformer through the fan alternating current collection line.
Referring to fig. 2, fig. 2 is a schematic structural diagram illustrating a penetration control system for flexible direct current output voltage of offshore wind power according to an embodiment of the present invention.
The embodiment of the invention provides an offshore wind power flexible direct current output voltage penetration control device which comprises a voltage acquisition device arranged on a land station, a cross-sea communication device and a voltage modulation control device arranged on an offshore station.
The voltage acquisition device of the onshore station is in high-speed communication connection with the voltage modulation control device of the offshore station through the cross-sea communication device. The voltage acquisition device is used for acquiring voltage waveforms of a grid connection point of an alternating current power grid and then sending the voltage waveforms to the voltage modulation control device through the cross-sea communication device. The voltage modulation control means of the marine station processes the voltage waveform into a modulated waveform for controlling the AC/DC converter of the marine station.
Specifically, the voltage modulation control device is used for processing the received alternating current voltage signal, generating a modulation signal and controlling the alternating current side of the AC/DC converter, so that the voltage of the offshore wind farm participates in the frequency modulation of the power grid.
The embodiment of the invention also provides an offshore wind power flexible direct current transmission voltage penetration control system which comprises the alternating current voltage penetration control device and an offshore wind power flexible direct current transmission system, wherein the offshore wind power flexible direct current transmission system comprises a land station, an offshore station and an offshore wind farm.
Referring to fig. 3, fig. 3 is a schematic flow chart illustrating a penetration control method for flexible direct current output voltage of offshore wind power according to an embodiment of the present invention.
Based on the device for controlling the penetration of the flexible direct current output voltage of the offshore wind power, the embodiment of the invention also provides a method for controlling the penetration of the flexible direct current output voltage of the offshore wind power, which comprises the following steps: collecting real-time voltage signals at the alternating current side of a land station; the method comprises the following steps of processing collected voltage signals to generate modulation signals, controlling an alternating current side of an AC/DC converter of an offshore station through the modulation signals, and enabling voltage of an offshore wind farm to participate in power grid frequency modulation, wherein the method specifically comprises the following steps:
s1, connecting a fan of the offshore wind farm with a second transformer through an alternating current collection bus according to an alternating current grid-connected mode of a land station, and configuring functions of frequency modulation, high voltage ride through, low voltage ride through and the like for the fan of the offshore wind farm.
And S2, collecting real-time voltage signals of the alternating current side of the ground station by a voltage collecting device of the ground station.
In this step, the real-time voltage signal on the ac side of the substation can be a voltage waveform represented per unit.
The per-unit expression means a relative unit system of a unit, and represents a relative value of each physical quantity and parameter, and the specific relationship is per-unit value = actual value/reference value.
And S3, the voltage acquisition device of the onshore station transmits the acquired onshore station alternating current voltage signal to the voltage modulation control device of the offshore station in real time.
And S4, the voltage modulation control device of the offshore station processes the received alternating current voltage signal, generates a modulation signal and controls the alternating current side of the AC/DC converter of the offshore station, so that the voltage of the offshore wind farm participates in the frequency modulation of the power grid.
In this step, the modulation signal may be a modulation waveform expressed per unit.
Specifically, the step of generating a modulation signal to control the alternating current side of the AC/DC converter so that the voltage of the offshore wind farm participates in the frequency modulation of the power grid comprises the following steps: the voltage modulation control device sends a modulation signal to the AC/DC converter, the AC/DC converter generates trigger pulses of each switching device in the AC/DC converter according to a modulation waveform expressed by per unit, each switching device is driven to trigger according to a pulse sequence, so that a voltage waveform which is consistent with the waveform of the onshore station alternating current power grid and the amplitude of which is scaled according to a set proportion is formed on the alternating current side of the offshore station, and finally alternating current collection voltage which is constant in transformation ratio with the onshore power grid is established in the offshore wind farm.
Specifically, the processing of the received ac voltage signal includes shaping, delay compensation, and three-phase balance processing after communication.
Shaping the communicated alternating current voltage waveform to obtain an ideal alternating current waveform; the acquired alternating voltage waveform is further subjected to time delay compensation, and the onshore power grid waveform at the moment can be accurately obtained by the offshore wind electric field, so that the delay of long-distance communication is compensated; the generated modulation waveform is three-phase symmetrical (equal amplitude and 120 degrees difference of phase angles) through three-phase balance processing.
And S5, when the frequency deviation occurs in the alternating current power grid, the alternating current voltage modulation control device generates a corresponding modulation signal to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in the power grid frequency modulation.
And S6, when the alternating current power grid has a high-voltage fault, the alternating current voltage modulation control device generates a corresponding modulation signal to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a high-voltage ride through function.
And S7, when the alternating current power grid has a low-voltage fault, the alternating current voltage modulation control device generates a corresponding modulation signal to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a low-voltage ride-through function.
It should be noted that the high voltage ride through function means that when the voltage of the grid-connected point is increased due to a power system fault or disturbance, the wind turbine generator/wind farm can be ensured to continuously operate without being disconnected within a certain voltage increase range and time interval.
The low voltage ride through function means that the terminal voltage of the wind driven generator system is reduced to a certain value, the wind driven generator system does not depart from the power grid and continues to operate, and even certain reactive power can be provided for the system to help the system recover the voltage. The wind driven generator with low voltage ride through capability can avoid the protection action time, and the normal operation is recovered after the fault is removed. The method can greatly reduce the repeated grid connection times of the power generation system during fault and reduce the impact on the power grid.
By the penetration control method for the offshore wind power flexible direct current sending voltage, the direct current transmission system has a transparent characteristic in the grid connection of an offshore wind farm to an onshore alternating current power grid. When the system is in normal operation, the offshore wind farm can normally participate in the frequency modulation of the power grid according to the sensed grid-connected voltage frequency and phase characteristics as if the offshore wind farm is directly connected to the alternating current power grid. During the fault period of the onshore alternating current power grid, the offshore wind farm can feel voltage drop if being directly merged into the power grid, and enters a low-voltage ride through function according to the voltage drop range, so that the problem that wind power is accumulated in a direct current transmission system is fundamentally avoided.
The offshore wind power soft direct-output alternating voltage penetration control system formed based on the embodiment of the invention not only utilizes the advantages of large direct current transmission capacity, long distance, no reactive power and stable power angle, but also retains the function that an alternating current grid-connected wind turbine generator can flexibly participate in system frequency modulation, and can process according to the original low voltage penetration principle of a fan without causing the rise of a direct current voltage pump when the output capacity of a transmission channel is reduced due to faults, thereby avoiding the requirement on a direct current energy consumption device.
Although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (12)
1. A penetration control method for flexible direct current output voltage of offshore wind power is characterized by comprising the following steps:
collecting real-time voltage signals of an alternating current side of a land station;
the collected voltage signals are processed to generate modulation signals, and the alternating current side of an AC/DC converter of the offshore station is controlled through the modulation signals, so that the voltage of the offshore wind farm participates in frequency modulation of a power grid.
2. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 1, wherein the modulation signal is generated to control the alternating current side of the AC/DC converter, so that the offshore wind farm voltage participating in the grid frequency modulation is as follows:
and the AC/DC converter generates trigger pulses of all switching devices in the AC/DC converter according to the modulation waveform, and drives all the switching devices to trigger according to the pulse sequence, so that a voltage waveform which is consistent with the waveform of the land station alternating current power grid and the amplitude of which is scaled according to a set proportion is formed on the alternating current side of the offshore station.
3. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 2, further comprising the steps of:
when frequency deviation occurs in an alternating current power grid of the onshore station, a corresponding modulation signal is generated to control an AC/DC converter of the offshore station, so that an offshore wind farm automatically participates in power grid frequency modulation.
4. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 2 or 3, characterized in that when a high voltage fault occurs in the onshore station alternating current grid, a corresponding modulation signal is generated to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a high voltage ride through function.
5. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 2 or 3, characterized in that when a low voltage fault occurs in an AC power grid of the onshore station, a corresponding modulation signal is generated to control an AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a low voltage ride through function.
6. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 1, wherein the real-time voltage signal on the alternating current side of the onshore station is a voltage waveform expressed per unit.
7. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 1, wherein the modulation signal is a modulation waveform expressed per unit.
8. The offshore wind power flexible direct current transmission voltage penetration control method according to claim 1, characterized in that the processing of the acquired voltage signal comprises shaping, time delay compensation and three-phase balance processing after communication.
9. A flexible direct current sending voltage penetration control device for offshore wind power is characterized by comprising a voltage acquisition device arranged on a land station, a cross-sea communication device and a voltage modulation control device arranged on the offshore station;
the voltage acquisition device is used for acquiring a real-time voltage signal at the AC side of the onshore station and then sending the real-time voltage signal to the voltage modulation control device through the cross-sea communication device;
the voltage modulation control device is used for processing the acquired voltage signal to generate a modulation signal, and controlling the alternating current side of the AC/DC converter of the offshore station through the modulation signal to enable the voltage of the offshore wind farm to participate in power grid frequency modulation.
10. The offshore wind power flexible direct current transmission voltage penetration control device according to claim 9, wherein the voltage modulation control device is specifically configured to:
and the AC/DC converter generates trigger pulses of all switching devices in the AC/DC converter according to the modulation waveform and drives all the switching devices to trigger according to the pulse sequence, so that a voltage waveform which is consistent with the waveform of the land station alternating current power grid and the amplitude of which is scaled according to a set proportion is formed at the alternating current side of the offshore station.
11. The offshore wind power flexible direct current transmission voltage penetration control device according to claim 10, wherein the voltage modulation control device is specifically configured to:
when frequency deviation occurs in an alternating current power grid of the onshore station, generating a corresponding modulation signal to control an AC/DC converter of the offshore station, so that an offshore wind farm automatically participates in power grid frequency modulation;
when a high-voltage fault occurs in an alternating current power grid of the onshore station, generating a corresponding modulation signal to control an AC/DC converter of the offshore station, so that an offshore wind farm automatically participates in executing a high-voltage ride-through function;
when the alternating current power grid of the onshore station has a low-voltage fault, a corresponding modulation signal is generated to control the AC/DC converter of the offshore station, so that the offshore wind farm automatically participates in executing a low-voltage ride-through function.
12. An offshore wind power flexible direct current transmission voltage penetration control system is characterized by comprising the offshore wind power flexible direct current transmission voltage penetration control device as claimed in any one of claims 9 to 11 and further comprising an offshore wind power flexible direct current transmission system, wherein the offshore wind power flexible direct current transmission system comprises a land station, an offshore station and an offshore wind farm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211486668.2A CN115528703A (en) | 2022-11-25 | 2022-11-25 | Penetration control method, device and system for flexible direct current output voltage of offshore wind power |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211486668.2A CN115528703A (en) | 2022-11-25 | 2022-11-25 | Penetration control method, device and system for flexible direct current output voltage of offshore wind power |
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| CN115528703A true CN115528703A (en) | 2022-12-27 |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110429616A (en) * | 2019-07-24 | 2019-11-08 | 全球能源互联网研究院有限公司 | A kind of active-the control method for frequency and system of the soft direct join net of marine wind electric field |
| CN110445170A (en) * | 2019-07-31 | 2019-11-12 | 全球能源互联网研究院有限公司 | A kind of active power and frequency control method and system of the soft direct join net of marine wind electric field |
| CN112421669A (en) * | 2020-12-10 | 2021-02-26 | 南方电网科学研究院有限责任公司 | Alternating current fault ride-through method and system for offshore wind power through flexible direct current transmission |
| US20220252046A1 (en) * | 2019-10-30 | 2022-08-11 | Zhejiang University | High-frequency uncontrolled rectifier-based dc transmission system for offshore wind farm |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110429616A (en) * | 2019-07-24 | 2019-11-08 | 全球能源互联网研究院有限公司 | A kind of active-the control method for frequency and system of the soft direct join net of marine wind electric field |
| CN110445170A (en) * | 2019-07-31 | 2019-11-12 | 全球能源互联网研究院有限公司 | A kind of active power and frequency control method and system of the soft direct join net of marine wind electric field |
| US20220252046A1 (en) * | 2019-10-30 | 2022-08-11 | Zhejiang University | High-frequency uncontrolled rectifier-based dc transmission system for offshore wind farm |
| CN112421669A (en) * | 2020-12-10 | 2021-02-26 | 南方电网科学研究院有限责任公司 | Alternating current fault ride-through method and system for offshore wind power through flexible direct current transmission |
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