CN110445171A - A kind of active power and frequency control method and system based on the soft lineal system of marine wind electric field - Google Patents

Abstract

The invention discloses an active frequency control method and system based on a flexible straight system of an offshore wind farm. The method includes: acquiring a frequency signal of an access point of an onshore AC power grid, and transmitting the frequency signal to a frequency active power modulation module in an onshore converter station ; Utilize the frequency active power modulation module based on the frequency signal to generate the power adjustment amount; detect whether the first inter-station communication system and the second inter-station communication system are normal; when the first inter-station communication system and the second inter-station communication system are normal , send the power adjustment amount to the offshore wind farm control system through the first inter-station communication system and the second inter-station communication system; then modulate the active power output by the offshore wind farm according to the power adjustment amount received by the offshore wind farm control system power. It realizes the modulation of the active power output by the offshore wind farm, thereby supporting the frequency modulation of the onshore AC system; the offshore wind power directly enters the frequency active power adjustment function of the access point of the onshore AC power grid through the flexible system.

Description

An active frequency control method and system based on a flexible straight system of an offshore wind farm

technical field

The invention relates to the technical field of new energy power generation, in particular to an active frequency control method and system based on a flexible straight system of an offshore wind farm.

Background technique

Based on the voltage source converter, the flexible DC transmission system has the advantages of no commutation failure, independent control of active power and reactive power, and the ability to supply power to passive networks. It provides an effective solution for renewable energy grid integration. In recent years, with the rapid development of large-scale and long-distance offshore wind power at home and abroad, a number of offshore flexible DC transmission projects are in the planning stage. In the future, offshore wind power can be directly connected to the onshore AC power grid through the flexibility. The transmission power of the wind farm is relatively large, and the frequency of the system has a certain influence on the normal operation of the power grid and the accident state, so the transmission power needs to be adjusted according to the frequency change of the AC system. In order to improve the overall performance of the power grid, it is necessary to introduce a frequency-based power modulation function in the flexible DC system.

At present, frequency-based DC power modulation has been applied in the conventional DC field. When the AC system on one side fails and the frequency changes abnormally, the DC transmission system can quickly respond to the frequency change on both sides and change the transmission power to support AC on both sides. Perform auxiliary frequency control. The power grid of the offshore wind farm in the prior art adopts a power control mode when outputting power, which cannot adjust the active power value output by the offshore wind farm according to the frequency of the onshore AC system, nor can it support the frequency modulation of the onshore AC system.

Contents of the invention

Therefore, the active frequency control method and system based on the flexible straight system of the offshore wind farm provided by the present invention overcomes that the existing technology does not adjust the active power value output by the offshore wind farm according to the frequency of the onshore AC system, and cannot support the onshore AC. System FM flaws.

In the first aspect, an embodiment of the present invention provides an active frequency control method based on a flexible straight system of an offshore wind farm, including: acquiring a frequency signal of an AC grid access point of the onshore AC system; transmitting the frequency signal to the onshore converter A frequency active power modulation module in the station; based on the frequency signal, using the frequency active power modulation module to generate a power adjustment amount;

Detect whether the first inter-station communication system between the onshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal; when the first inter-station communication system and the second station When the inter-station communication systems are normal, the power adjustment amount is sent to the offshore wind farm control system through the first inter-station communication system and the second inter-station communication system; according to the power received by the offshore wind farm control system The adjustment variable modulates the active power output by the offshore wind farm.

Optionally, the active frequency control method based on the flexible straight system of the offshore wind farm further includes: when the first inter-station communication system and/or the second inter-station communication system are abnormal, the offshore wind farm output.

Optionally, the step of acquiring the frequency signal of the access point of the onshore AC grid includes: using a phase-locked loop to measure the frequency of the access point of the onshore AC grid in real time, and generating the frequency signal after filtering.

Optionally, the modulation mode in the frequency active power modulation module includes: at least one of a frequency sensitive mode, a high frequency limited frequency sensitive mode, and a low frequency limited frequency sensitive mode.

Optionally, the step of using the frequency active power modulation module to generate a power adjustment amount based on the frequency signal includes: selecting a modulation mode in the frequency active power modulation module according to a preset frequency modulation requirement; The preset algorithm generates a power adjustment amount based on the preset rated frequency, the preset contract flexible DC power and the frequency signal.

In the second aspect, the embodiment of the present invention also provides an active frequency control system of an offshore wind farm, including: a frequency signal acquisition module, used to acquire the frequency signal of the access point of the onshore AC power grid; a frequency signal transmission module, used to transfer the The frequency signal is transmitted to the frequency active power modulation module in the onshore converter station; the power adjustment amount generation module is used to generate the power adjustment amount by using the frequency active power modulation module based on the frequency signal; the communication system detection module is used to detect the shore conversion Whether the first inter-station communication system between the offshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal; the power adjustment value sending module, when the first inter-station communication system and the second inter-station communication system When the two inter-station communication systems are normal, the power adjustment amount is sent to the offshore wind farm control system through the first inter-station communication system and the second inter-station communication system; the active power modulation module is used to The power adjustment amount received by the wind farm control system modulates the active power output by the offshore wind farm.

Optionally, the power adjustment quantity generation module includes: a modulation mode selection submodule, configured to select a modulation mode in the frequency active power modulation module according to preset frequency modulation requirements; a power adjustment quantity generation submodule, according to the modulation mode in the modulation mode The preset algorithm generates a power adjustment amount based on the preset rated frequency, the preset contract flexible DC power and the frequency signal.

Optionally, the active frequency control system of the offshore wind farm further includes: a control parameter setting module, configured to set control parameters, including: a frequency threshold, a proportional coefficient, and a maximum value for active power adjustment.

In a third aspect, an embodiment of the present invention provides a computer device, including: at least one processor, and a memory connected in communication with the at least one processor, wherein the memory stores information that can be executed by the at least one processor. instructions, the instructions are executed by the at least one processor, so that the at least one processor executes the active frequency control method based on the flexible straight system of the offshore wind farm according to the first aspect of the embodiments of the present invention.

In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method based on the first aspect of the embodiment of the invention. Active frequency control method for flexible straight systems in offshore wind farms.

The technical solution of the present invention has the following advantages:

The active power frequency control method based on the flexible straight system of the offshore wind farm provided by the embodiment of the present invention obtains the frequency signal of the access point of the onshore AC power grid, and then transmits the frequency signal to the frequency active power modulation module in the onshore converter station; based on the frequency signal Use the frequency active power modulation module to generate power regulation; then check whether the first inter-station communication system between the onshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal ; When both the first inter-station communication system and the second inter-station communication system are normal, the power adjustment amount is sent to the offshore wind farm control system through the first inter-station communication system and the second inter-station communication system;

Then the active power output by the offshore wind farm is modulated according to the power adjustment amount received by the offshore wind farm control system. Through the above method, the frequency signal of the onshore AC grid access point of the AC system is passed through the frequency active power modulation module in the onshore converter station to generate a power adjustment value, thereby modulating the active power output by the offshore wind farm, thereby supporting the onshore AC system for frequency modulation ; Realize the frequency active power adjustment function of the offshore wind power directly entering the access point of the onshore AC power grid through the flexible.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

FIG. 1 is a flow chart of a specific example of an active frequency control method based on an offshore wind farm flexible system provided by an embodiment of the present invention;

FIG. 2 is a composition diagram of a specific example of an offshore wind farm power grid system provided by an embodiment of the present invention. An active frequency control method based on an offshore wind farm flexible straight system;

Fig. 3 is a block diagram of frequency-based frequency active power control transfer function provided by an embodiment of the present invention;

Fig. 4 is a flow chart of another specific example of an active frequency control method based on an offshore wind farm flexible straightening system provided by an embodiment of the present invention;

5 is a flow chart of a specific example of generating a power adjustment amount based on a frequency signal and using a frequency active power modulation module according to an embodiment of the present invention;

FIG. 6 is a modulation curve diagram of a frequency-sensitive mode in the modulation mode provided by an embodiment of the present invention;

FIG. 7 is a modulation curve diagram of a high frequency limited frequency sensitive mode in the modulation mode provided by an embodiment of the present invention;

FIG. 8 is a modulation curve diagram of a low frequency limited frequency sensitive mode in the modulation mode provided by an embodiment of the present invention;

FIG. 9 is a test waveform of the frequency sensitive mode in the modulation mode in the frequency active power modulation module provided by the embodiment of the present invention;

Fig. 10 is a test waveform of a high frequency frequency sensitive mode in the modulation mode in the frequency active power modulation module provided by the embodiment of the present invention;

Fig. 11 is the test waveform of the low frequency frequency sensitive mode in the modulation mode in the frequency active power modulation module provided by the embodiment of the invention;

Fig. 12 is a simulation result diagram of the frequency sensitive mode in the modulation mode in the frequency active power modulation module provided by the embodiment of the present invention;

Fig. 13 is a simulation result diagram of the high frequency frequency sensitive mode in the modulation mode in the frequency active power modulation module provided by the embodiment of the present invention;

Fig. 14 is a simulation result diagram of the low frequency frequency sensitive mode in the modulation mode in the frequency active power modulation module provided by the embodiment of the invention;

Fig. 15 is a schematic composition diagram of the active frequency control system of the offshore wind farm provided by the embodiment of the invention;

Fig. 16 is another schematic composition diagram of the active frequency control system of the offshore wind farm provided by the embodiment of the invention;

FIG. 17 is a composition diagram of a specific example of computer equipment provided by an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

Example 1

As shown in Figure 1, an embodiment of the present invention provides an active frequency control method based on the flexible straight system of an offshore wind farm, the control method includes the following steps:

Step S1: Obtain the frequency signal of the access point of the AC power grid of the shore AC system. In the embodiment of the present invention, as shown in Figure 3 is a frequency-based frequency active power control transfer function block diagram, in which the shore AC system uses a phase-locked loop (PLL) to measure the frequency of the AC grid access point of the shore AC system in real time, after a The first frequency signal is generated after first-order filter processing, which is just an example and not limited thereto.

Step S2: Transmit the frequency signal to the frequency active power modulation module in the onshore converter station.

Step S3: Using the frequency active power modulation module based on the frequency signal to generate a power adjustment amount. The frequency active power modulation module is equipped with multiple modulation modes. After the operator selects the modulation mode through the Human Machine Interface (HMI) according to actual needs, the frequency signal will be calculated according to the preset algorithm in the selected modulation mode. Finally, a power adjustment ΔP is generated.

Step S4: Detect whether the first inter-station communication system between the onshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal. Since the above-mentioned generated power regulation ΔP needs to pass through the offshore converter station before it can be transmitted to the offshore wind farm control system, so before the transmission, Xi needs to check the communication system between the onshore converter station and the first station of the offshore converter station and the offshore converter station. Whether the second inter-station communication system between the flow station and the offshore wind farm is normal.

Step S5: When both the first inter-station communication system and the second inter-station communication system are normal, as shown in Figure 2, the power adjustment amount is sent through the first inter-station communication system and the second inter-station communication system to offshore wind farm control systems. The first inter-station communication system set up between the onshore converter station and the offshore converter station, and the second inter-station communication system between the offshore converter station and the offshore wind farm can transfer the power regulation ΔP from the onshore converter station to transmitted to the offshore wind farm control system; when the power regulation ΔP is sent to the offshore wind farm control system through the first inter-station communication system and the second inter-station communication system, the first inter-station communication system and the second inter-station communication system pass Self-inspection determines whether the current communication is normal; when it is determined that the first inter-station communication system and the second inter-station communication system are normal, the power adjustment value ΔP can be transmitted from the onshore converter station to the offshore wind farm control system.

It should be noted that both the first inter-station communication system and the second inter-station communication system are equipped with redundant communication loops, and the power adjustment value ΔP can be transmitted through multiple communication lines. When one of the communication lines fails, It does not affect the normal signal transmission to ensure the reliability of the signal. In practical applications, there may be a communication delay during signal transmission, and the delay is about 50ms.

Step S6: Modulate the active power output by the offshore wind farm according to the power adjustment amount received by the offshore wind farm control system. In practical applications, the offshore wind farm is equipped with an offshore wind farm control and protection system, an offshore wind farm energy management system, and multiple wind farm units; when the offshore wind farm control system receives the power adjustment value ΔP, the power adjustment value ΔP will be It is transmitted to the offshore wind farm energy management system by the offshore wind farm control system; when the offshore wind farm energy management system receives the active power adjustment amount ΔP, it is distributed to multiple wind farm units in the offshore wind farm to regulate the entire offshore wind farm Output active power.

Through the above steps S1 to S6, the embodiment of the present invention provides an active power frequency control method based on the flexible DC system of the offshore wind farm. The modulation module generates the power adjustment value ΔP, thereby modulating the active power output by the offshore wind farm, thereby supporting the frequency modulation of the onshore AC system; realizing the frequency active power adjustment function of the offshore wind power directly entering the access point of the onshore AC grid through the flexible.

In an embodiment, as shown in FIG. 4 , when the first inter-station communication system between the onshore converter station and the offshore converter station and/or the second inter-station communication system between the offshore converter station and the offshore wind farm is not Normally, the active frequency control method based on the flexible straight system of the offshore wind farm further includes step S7: the offshore wind farm outputs according to a preset active power value. When the first inter-station communication system and/or the second inter-station communication system detects that the inter-station communication system is abnormal through self-inspection, the frequency active power modulation module will be disabled and return to the original control mode, that is, the onshore converter station will generate The active power is transmitted to the offshore converter station.

As shown in FIG. 5, in an embodiment, the above step S3 uses a frequency active power modulation module based on a frequency signal to generate a power adjustment amount, which specifically includes:

Step S31: Select a modulation mode in the frequency active power modulation module according to a preset frequency modulation requirement. Modulation modes include: at least one of Frequency Sensitive Mode (FSM), High Frequency Limited Frequency Sensitive Mode (LFSM-O), and Low Frequency Limited Frequency Sensitive Mode (LFSM-U); A control interface (Human Machine Interface, HMI) selects at least one modulation mode for detailed parameter setting, including parameters such as a frequency threshold, a proportional coefficient, and a maximum value of active power adjustment.

Step S32: According to a preset algorithm in the modulation mode, a power adjustment amount ΔP is generated based on the preset rated frequency, the preset contract flexible DC power and the frequency signal. According to actual needs, after the operator selects the modulation mode through the man-machine control interface, as shown in Figures 6 to 8, the power adjustment amount is finally calculated according to the preset rated frequency f _n , the preset contract flexible DC power p _AV and the frequency signal f ΔP. In frequency sensitive mode (FSM), high frequency limited frequency sensitive mode (LFSM-O) and low frequency limited frequency sensitive mode (LFSM-U), modulation curves as shown in Fig. 6 to Fig. 8 are preset . For example: when the operator chooses to use the frequency sensitive mode (FSM) through the man-machine control interface, first calculate the difference Δf between the frequency signal f and the preset rated frequency f _n , and then calculate the difference between Δf and the preset rated frequency The proportional coefficient of f _n , according to the proportional coefficient and the modulation curve, the proportional coefficient between the power adjustment amount ΔP and the contract DC power p _AV is obtained. Since the contract DC power p _AV is known, the power adjustment amount ΔP is obtained; when If the calculated power adjustment ΔP is equal to zero, it means that the power adjustment ΔP has not changed, that is, the active power generated by the onshore converter station is transmitted to the offshore converter station. Specifically, as shown in FIG. 6, it is a modulation curve diagram of a frequency-sensitive mode in the modulation mode provided by the embodiment of the present invention; wherein, ΔP: modulation amount of DC power; ΔP ₁ : frequency limit f ₁ (50.2 Hz) Corresponding DC power modulation quantity; ΔP ₂ : corresponding DC power modulation quantity when the frequency is limited to f ₂ (49.8Hz); p _AV : contract flexible DC power; Δf _tot : frequency control dead zone; f _n : rated frequency (50Hz) ; Δf: frequency deviation of the AC grid; Δf _tolerance : allowable error; s ₁ : droop at low frequency (6%); s ₂ : droop at high frequency (6%). Fig. 7 is a modulation curve diagram of the high frequency limited frequency sensitive mode in the modulation mode provided by the embodiment of the present invention; wherein, ΔP: modulation amount of DC power; p _AV : contract flexible DC power; f _n : rated frequency (50Hz) ; Δf: deviation of AC grid frequency; f ₁ : frequency threshold: 50.2 Hz; s ₃ : droop coefficient of LFSM-O: 5%. Fig. 8 is a modulation curve diagram of the low frequency limited frequency sensitive mode among the modulation modes provided by the embodiment of the present invention; where, ΔP: modulation amount of DC power; p _AV : contract flexible DC power; f _n : rated frequency; Δf: AC Grid frequency deviation; f ₁ : frequency threshold: 49.8Hz; s ₄ : droop coefficient of LFSM-U: 5%.

The active power frequency control method based on the flexible straight system of the offshore wind farm provided by the embodiment of the present invention generates a power adjustment value ΔP through the frequency signal of the access point of the onshore AC power grid through the frequency active power modulation module in the onshore converter station, thereby modulating the offshore wind power. The active power output by the farm can support the frequency regulation of the onshore AC system; the frequency active power adjustment function of the offshore wind power directly entering the access point of the onshore AC power grid is realized.

The active frequency control method based on the flexible straight system of the offshore wind farm provided by the embodiment of the present invention is analyzed through simulation modeling in PSCAD/EMTDC, wherein the rated power of the flexible straight system is 900MW, and the rated DC voltage is ±320kV; the shore AC system, etc. The efficiency is a 380kV voltage source, and the short-circuit ratio SCR=5; the offshore wind farm model includes double-fed wind turbines and direct-drive wind turbines, each of which accounts for 50% of the total output of the wind farm. Apply the following frequency test waveforms to test the frequency power control function. The frequency test waveforms are shown in Figures 9 to 11, and the simulation results are shown in Figures 12 to 14. Among them, Simulated means the data obtained by simulation, and Required means that the corresponding frequency The theoretical value after setting according to certain parameters in the active power modulation mode, ΔP is the power adjustment amount, p _AV is the contract flexible DC power, Δf is the difference between the frequency signal f and the preset rated frequency f _n , that is, the AC grid frequency The deviation, f _n is the preset rated frequency.

From the above simulation results, it can be shown that the control method provided by the embodiment of the present invention can effectively adjust the active power output by the offshore wind farm according to the frequency signal of the AC grid access point of the onshore AC system, and realize the support for the frequency adjustment of the AC system. It is suitable for projects where offshore wind power directly enters through the soft route.

Example 2

As shown in Figure 15, an embodiment of the present invention also provides an active frequency control system for an offshore wind farm, including:

The frequency signal acquisition module 1 is used to acquire the frequency signal of the access point of the onshore AC power grid. This module executes the method described in step S1 in Embodiment 1, which will not be repeated here.

The frequency signal transmission module 2 is used to transmit the frequency signal to the frequency active power modulation module in the onshore converter station. This module executes the method described in step S2 in Embodiment 1, which will not be repeated here.

The power adjustment amount generating module 3 is configured to use the frequency active power modulation module to generate a power adjustment amount based on the frequency signal. This module executes the method described in step S3 in Embodiment 1, which will not be repeated here.

The communication system detection module 4 is used to detect whether the first inter-station communication system between the onshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal. This module executes the method described in step S4 in Embodiment 1, which will not be repeated here.

The power adjustment amount sending module 5, when the first inter-station communication system and the second inter-station communication system are normal, the power adjustment amount is sent to the sea through the first inter-station communication system and the second inter-station communication system Wind farm control system. This module executes the method described in step S5 in Embodiment 1, which will not be repeated here.

The active power modulation module 6 is configured to modulate the active power output by the offshore wind farm according to the power adjustment amount received by the offshore wind farm control system. This module executes the method described in step S6 in Embodiment 1, which will not be repeated here.

In an embodiment, the power adjustment amount generation module 3 specifically includes: a modulation mode selection sub-module, configured to select a modulation mode in the frequency active power modulation module according to a preset frequency modulation requirement. This module executes the method described in step S31 in Embodiment 1, which will not be repeated here.

The power adjustment amount generation sub-module generates the power adjustment amount based on the preset rated frequency, the preset contract flexible DC power and the frequency signal according to the preset algorithm in the modulation mode. This module executes the method described in step S32 in Embodiment 1, which will not be repeated here.

As shown in Figure 16, the active frequency control system of the offshore wind farm provided by the embodiment of the present invention also includes: a control parameter setting module 7, which is used to set the control parameters, including: frequency threshold, proportional coefficient and maximum value of active power adjustment . In the embodiment of the present invention, the operation and maintenance staff can select and set detailed control parameters through the man-machine control interface, including parameters such as frequency threshold, proportional coefficient, and maximum value of active power adjustment. This is just an example and not limited to this .

The active frequency control system of the offshore wind farm provided by the embodiment of the present invention, through the frequency signal acquisition module 1, the frequency signal transmission module 2, the power adjustment amount generation module 3, the communication system detection module 4, the power adjustment amount transmission module 5 and the active power The modulation module 6 can generate a power adjustment value ΔP by passing the frequency signal of the access point of the onshore AC power grid through the frequency active power modulation module in the onshore converter station, thereby modulating the active power output by the offshore wind farm, thereby supporting the onshore AC system for frequency modulation ; Realize the frequency active power adjustment function of the offshore wind power directly entering the access point of the onshore AC power grid through the flexible.

Example 3

An embodiment of the present invention provides a computer device, as shown in FIG. 17 , including: at least one processor 401, such as a CPU (Central Processing Unit, central processing unit), at least one communication interface 403, memory 404, and at least one communication bus 402 . Wherein, the communication bus 402 is used to realize connection and communication between these components. Wherein, the communication interface 403 may include a display screen (Display) and a keyboard (Keyboard), and the optional communication interface 403 may also include a standard wired interface and a wireless interface. The memory 404 may be a high-speed RAM memory (Ramdom Access Memory, volatile random access memory), or a non-volatile memory (non-volatile memory), such as at least one disk memory. Optionally, the memory 404 may also be at least one storage device located away from the aforementioned processor 401 . Wherein the processor 401 can execute the active frequency control method based on the flexible straight system of the offshore wind farm in Embodiment 1. A set of program codes are stored in the memory 404, and the processor 401 invokes the program codes stored in the memory 404 to implement the active frequency control method based on the flexible straight system of the offshore wind farm in Embodiment 1.

Wherein, the communication bus 402 may be a peripheral component interconnect (PCI for short) bus or an extended industry standard architecture (EISA for short) bus or the like. The communication bus 402 can be divided into address bus, data bus, control bus and so on. For ease of representation, only one line is used in FIG. 17 , but it does not mean that there is only one bus or one type of bus.

Wherein, the memory 404 may include a volatile memory (English: volatile memory), such as a random-access memory (English: random-access memory, abbreviation: RAM); the memory may also include a non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory), hard disk (English: hard diskdrive, abbreviation: HDD) or solid-state hard disk (English: solid-state drive, abbreviation: SSD); memory 404 can also include the above-mentioned types combination of memory.

Wherein, the processor 401 may be a central processing unit (English: central processing unit, abbreviated: CPU), a network processor (English: network processor, abbreviated: NP) or a combination of CPU and NP.

Wherein, the processor 401 may further include a hardware chip. The aforementioned hardware chip may be an application-specific integrated circuit (English: application-specific integrated circuit, abbreviation: ASIC), a programmable logic device (English: programmable logic device, abbreviation: PLD) or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (English: complex programmable logic device, abbreviation: CPLD), field-programmable logic gate array (English: field-programmable gate array, abbreviation: FPGA), general array logic (English: generic array logic , Abbreviation: GAL) or any combination thereof.

Optionally, the memory 404 is also used to store program instructions. The processor 401 may invoke program instructions to implement the active frequency control method based on the flexible straight system of the offshore wind farm as in Embodiment 1 of the present application.

The embodiment of the present invention also provides a computer-readable storage medium, on which computer-executable instructions are stored, and the computer-executable instructions can execute the active frequency control based on the flexible straight system of the offshore wind farm in Embodiment 1 method. Wherein, the storage medium can be a magnetic disk, an optical disk, a read-only memory (Read-OnlyMemory, ROM), a random access memory (Random Access Memory, RAM), a flash memory (FlashMemory), a hard disk (Hard Disk Drive) , abbreviation: HDD) or Solid-State Drive (SSD), etc.; the storage medium may also include a combination of the above-mentioned types of memories.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. However, the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. An active frequency control method based on offshore wind farm soft straight system, characterized in that, comprising: Obtain the frequency signal of the AC grid access point of the shore AC system; Transmitting the frequency signal to the frequency active power modulation module in the onshore converter station; using the frequency active power modulation module to generate a power adjustment amount based on the frequency signal; Detect whether the first inter-station communication system between the onshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal; When both the first inter-station communication system and the second inter-station communication system are normal, the power adjustment amount is sent to the offshore wind farm control system through the first inter-station communication system and the second inter-station communication system; The active power output by the offshore wind farm is modulated according to the power adjustment amount received by the offshore wind farm control system. 2. The active frequency control method based on the flexible straight system of the offshore wind farm according to claim 1, further comprising: When the first inter-station communication system and/or the second inter-station communication system are abnormal, the offshore wind farm outputs according to a preset active power value. 3. The active frequency control method based on the flexible straight system of the offshore wind farm according to claim 1, wherein the step of obtaining the frequency signal of the access point of the onshore AC power grid comprises: The phase-locked loop is used to measure the frequency of the access point of the onshore AC power grid in real time, and the frequency signal is generated after filtering. 4. The active frequency control method based on the flexible straight system of the offshore wind farm according to claim 1, wherein the modulation modes in the frequency active power modulation module include: frequency sensitive mode, high frequency limited frequency sensitive mode, low frequency At least one of the limited frequency sensitive modes. 5. The active frequency control method based on the flexible straight system of the offshore wind farm according to claim 4, wherein the step of generating a power adjustment amount using the frequency active power modulation module based on the frequency signal comprises: selecting a modulation mode in the frequency active power modulation module according to a preset frequency modulation requirement; According to a preset algorithm in the modulation mode, a power adjustment amount is generated based on a preset rated frequency, a preset contract flexible DC power, and the frequency signal. 6. An active frequency control system of an offshore wind farm, characterized in that it comprises: The frequency signal acquisition module is used to acquire the frequency signal of the AC grid access point of the shore AC system; A frequency signal transmission module, configured to transmit the frequency signal to the frequency active power modulation module in the onshore converter station; A power adjustment amount generating module, configured to generate a power adjustment amount by using the frequency active power modulation module based on the frequency signal; The communication system detection module detects whether the first inter-station communication system between the onshore converter station and the offshore converter station and the second inter-station communication system between the offshore converter station and the offshore wind farm are normal; The power adjustment amount sending module, when both the first inter-station communication system and the second inter-station communication system are normal, send the power adjustment amount to the offshore wind power plant through the first inter-station communication system and the second inter-station communication system field control system; An active power modulation module, configured to modulate the active power output by the offshore wind farm according to the power adjustment amount received by the offshore wind farm control system. 7. The active frequency control system of the offshore wind farm according to claim 6, wherein the power regulation generating module comprises: A modulation mode selection submodule, used to select the modulation mode in the frequency active power modulation module according to preset frequency modulation requirements; The power adjustment amount generation sub-module generates the power adjustment amount based on the preset rated frequency, the preset contract flexible DC power and the frequency signal according to the preset algorithm in the modulation mode. 8. The active frequency control system of an offshore wind farm according to claim 6, further comprising: The control parameter setting module is used to set control parameters, including: frequency threshold, proportional coefficient and maximum value of active power adjustment. 9. A computer device, characterized in that it comprises: at least one processor, and a memory connected in communication with the at least one processor, wherein the memory stores instructions executable by the at least one processor, The instructions are executed by the at least one processor according to any one of claims 1-5 based on the active frequency control method of the flexible straight system of the offshore wind farm. 10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, and the computer instructions are used to make the computer execute the offshore wind power-based system according to any one of claims 1-5. Active frequency control method of field flexible straight system.