Frequency fluctuation suppression method and device for alternating current system of offshore wind plant

Abstract

The invention provides a frequency fluctuation suppression method and device for an offshore wind plant alternating current system, and the method comprises the steps: determining a real-time frequency value of the offshore wind plant alternating current system, determining a frequency fluctuation value between the real-time frequency value and a preset frequency value, processing the frequency fluctuation value based on a frequency loop, and obtaining a target integral value, according to the frequency fluctuation value and the target integral value, a voltage controller is controlled to generate a voltage control instruction, the voltage controller is used for controlling the part, in the same phase as the power grid voltage, of the alternating voltage of the offshore wind plant alternating-current system after Park conversion, and the voltage control instruction is used for reducing the difference value between the real-time frequency value and the preset frequency value. By implementing the method disclosed by the invention, the frequency loop can be introduced to correct the instruction value of the voltage controller, so that the suppression effect on the frequency fluctuation of the system is effectively improved, and the safety and stability of the system are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power control, and in particular to a method and device for suppressing frequency fluctuations of an AC system of an offshore wind farm. Background Art

[0002] Based on the MMC-HVDC direct current transmission system, the main grid AC system and the offshore wind farm AC system can be isolated, so that the short-circuit fault of the main grid AC system cannot be transmitted to the wind farm side, thus not affecting the normal operation of the wind turbine. When the offshore wind farm is subjected to a relatively large disturbance, such as a short-circuit fault, the AC voltage amplitude and frequency will be impacted, resulting in large fluctuations, which may affect the safety of the system.

[0003] In the related art, the suppression effect of the frequency fluctuation of AC voltage at sea is not good. Summary of the invention

[0004] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the purpose of the present invention is to propose a method, device, computer equipment and storage medium for suppressing frequency fluctuations in an offshore wind farm AC system, which can introduce a frequency loop to correct the command value of a voltage controller, thereby effectively improving the suppression effect of system frequency fluctuations and improving the safety and stability of the system.

[0006] To achieve the above-mentioned purpose, a method for suppressing frequency fluctuations of an offshore wind farm AC system proposed in a first aspect of the present disclosure includes:

[0007] Determine the real-time frequency value of the AC system of the offshore wind farm;

[0008] Determining a frequency fluctuation value between the real-time frequency value and a preset frequency value;

[0009] Processing the frequency fluctuation value based on the frequency loop to obtain a target integral value;

[0010] According to the frequency fluctuation value and the target integral value, a voltage controller is controlled to generate a voltage control instruction, wherein the voltage controller is used to control the part of the AC voltage of the offshore wind farm AC system that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value.

[0011] To achieve the above-mentioned purpose, a frequency fluctuation suppression device for an offshore wind farm AC system according to a second aspect of the present disclosure includes:

[0012] A first determination module is used to determine a real-time frequency value of an AC system of an offshore wind farm;

[0013] A second determination module, used to determine a frequency fluctuation value between the real-time frequency value and a preset frequency value;

[0014] A processing module, used for processing the frequency fluctuation value based on the frequency loop to obtain a target integral value;

[0015] A control module is used to control a voltage controller to generate a voltage control instruction according to the frequency fluctuation value and the target integral value, wherein the voltage controller is used to control the part of the AC voltage of the offshore wind farm AC system that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value.

[0016] The computer device proposed in the third aspect embodiment of the present disclosure includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the frequency fluctuation suppression method of the offshore wind farm AC system proposed in the first aspect embodiment of the present disclosure is implemented.

[0017] The fourth aspect embodiment of the present disclosure proposes a non-temporary computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the frequency fluctuation suppression method of the offshore wind farm AC system proposed in the first aspect embodiment of the present disclosure.

[0018] The fifth aspect of the present disclosure provides a computer program product. When the instructions in the computer program product are executed by a processor, the method for suppressing frequency fluctuations of an offshore wind farm AC system provided in the first aspect of the present disclosure is performed.

[0019] The present disclosure provides a method, device, computer equipment and storage medium for suppressing frequency fluctuations of an offshore wind farm AC system. The method determines the real-time frequency value of the offshore wind farm AC system, determines the frequency fluctuation value between the real-time frequency value and the preset frequency value, processes the frequency fluctuation value based on a frequency loop, and obtains a target integral value, wherein the frequency loop belongs to the offshore wind farm AC system, and controls a voltage controller to generate a voltage control instruction based on the frequency fluctuation value and the target integral value, wherein the voltage controller is used to control the part of the AC voltage of the offshore wind farm AC system that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value, thereby introducing a frequency loop to correct the instruction value of the voltage controller, thereby effectively improving the suppression effect on the system frequency fluctuation and improving the safety and stability of the system.

[0020] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0022] Figure 1 It is a flow chart of a method for suppressing frequency fluctuations of an AC system of an offshore wind farm proposed in one embodiment of the present disclosure;

[0023] Figure 2 is a flow chart of a method for suppressing frequency fluctuations of an AC system of an offshore wind farm proposed in another embodiment of the present disclosure;

[0024] Figure 3 is a schematic diagram of the structure of the frequency control system of the offshore converter station proposed in the present disclosure;

[0025] Figure 4 It is a structural schematic diagram of a frequency fluctuation suppression device for an offshore wind farm AC system proposed in one embodiment of the present disclosure;

[0026] Figure 5 A block diagram of an exemplary computer device suitable for implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0027] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and are not to be construed as limitations of the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications, and equivalents that fall within the spirit and connotation of the appended claims.

[0028] Figure 1 It is a flow chart of a method for suppressing frequency fluctuations of an AC system of an offshore wind farm proposed in an embodiment of the present disclosure.

[0029] Among them, it should be noted that the executor of the frequency fluctuation suppression method of the offshore wind farm AC system of this embodiment is the frequency fluctuation suppression device of the offshore wind farm AC system, which can be implemented by software and / or hardware. The device can be configured in a computer device, and the computer device can include but is not limited to a terminal, a server, etc. For example, the terminal can be a mobile phone, a handheld computer, etc.

[0030] like Figure 1 As shown, the frequency fluctuation suppression method of the offshore wind farm AC system includes:

[0031] S101: Determine a real-time frequency value of an AC system of an offshore wind farm.

[0032] The real-time frequency value refers to the frequency value of the AC system of the offshore wind farm obtained in real time.

[0033] In the disclosed embodiment, when determining the real-time frequency value of the AC system of the offshore wind farm, it may be based on a third-party frequency determination device, or it may be based on an engineering method, and there is no limitation on this.

[0034] It can be understood that the AC system of an offshore wind farm may cause fluctuations in its system frequency due to the influence of abnormal factors. In the embodiment of the present disclosure, when determining the real-time frequency value of the AC system of an offshore wind farm, real-time supervision of the corresponding system frequency of the AC system of the offshore wind farm can be achieved, thereby providing reliable data support for the subsequent determination of the frequency fluctuation value of the AC system of the offshore wind farm.

[0035] S102: Determine a frequency fluctuation value between a real-time frequency value and a preset frequency value.

[0036] The preset frequency value may refer to, for example, a system frequency value pre-configured for an AC system of an offshore wind farm.

[0037] The frequency fluctuation value may refer to the difference between the real-time frequency value and the preset frequency value. When the frequency fluctuation value is less than zero, the real-time frequency value of the AC system of the offshore wind farm is lower than the preset frequency value; when the frequency fluctuation value is greater than zero, the real-time frequency value of the AC system of the offshore wind farm is higher than the preset frequency value.

[0038] In the embodiment of the present disclosure, when the frequency fluctuation value between the real-time frequency value and the preset frequency value is determined, reliable reference information can be provided for the subsequent control of the voltage controller to generate a voltage control instruction.

[0039] S103: Process the frequency fluctuation value based on the frequency loop to obtain a target integral value.

[0040] The frequency loop refers to a closed-loop feedback system used to measure and control the frequency of a signal. It generates an error signal by comparing the frequency of the input signal with the reference frequency (or target frequency), and performs feedback adjustment through the control loop so that the frequency of the output signal gradually approaches the target frequency.

[0041] The target integral value is based on the integral value output by the frequency loop processing the frequency fluctuation value.

[0042] It is understandable that the output result of the frequency loop is the integral value of the frequency fluctuation, which is usually called frequency deviation or cumulative phase error. The physical meaning of frequency deviation is that it reflects the cumulative difference between the actual signal frequency and the target frequency. If the frequency deviation is zero, it means that the frequency of the input signal is exactly the same as the target frequency. A non-zero frequency deviation means that there is a difference between the actual frequency and the target frequency.

[0043] The positive and negative value and absolute value of the frequency deviation can provide some important information:

[0044] Sign: The sign of the frequency deviation indicates whether the actual frequency is higher or lower than the target frequency. A positive value indicates that the actual frequency is higher than the target frequency, and a negative value indicates that the actual frequency is lower than the target frequency.

[0045] Absolute value size: The absolute value size of the frequency deviation indicates the difference between the actual frequency and the target frequency. A small frequency deviation means that the actual frequency is very close to the target frequency, while a large frequency deviation means that there is a large frequency difference.

[0046] By controlling the feedback adjustment mechanism in the frequency loop, the goal is to reduce the frequency deviation as much as possible so that the frequency of the input signal gradually approaches the target frequency. In this way, the integral value of the frequency deviation becomes an indicator that reflects the frequency stability and tracking ability. According to the change of the integral value, the performance and stability of the frequency loop can be judged, and corresponding adjustments and optimizations can be made.

[0047] In the disclosed embodiment, when the frequency fluctuation value is processed based on the frequency loop to obtain the target integral value, the frequency loop can be introduced in the frequency fluctuation suppression process of the offshore wind farm AC system, thereby providing reliable reference information for controlling the voltage controller to generate voltage control instructions.

[0048] S104: According to the frequency fluctuation value and the target integral value, control the voltage controller to generate a voltage control instruction, wherein the voltage controller is used to control the part of the AC voltage of the AC system of the offshore wind farm that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value.

[0049] The voltage controller, for example, may refer to a controller for controlling the q-axis voltage after the AC voltage undergoes Park transformation.

[0050] The voltage control instruction refers to a control instruction for indicating the q-axis voltage value determined based on the frequency fluctuation value and the target integral value in the embodiment of the present disclosure.

[0051] It can be understood that when the system is in steady state, the bus voltage is stable and can be considered as an ideal sine wave, which can be described as

[0052] u(t)=U0cos(2πf0t+θ1)

[0053] Where θ1 is the initial phase of the AC voltage, and U0, f0, and θ1 are all constants.

[0054] When an offshore wind farm is subjected to a relatively large disturbance, such as a short circuit fault, the AC voltage amplitude and frequency will be impacted and produce large fluctuations. At this time, the actual voltage is no longer in a strict sinusoidal form and can be described in the form of the following formula.

[0055] u(t)=U(t)cos(θ s (t)+θ1)

[0056] U(t) and θ s (t) is the actual amplitude and phase, and the frequency of the system is

[0057]

[0058] In the outer loop control of the offshore MMC converter station, the controller controls the voltage at the PCC point and the AC voltage U after park transformation. sd , U sq To control, U sd , U sq The relationship with AC voltage is

[0059]

[0060] After the park inverse transformation, the AC voltage can be expressed as

[0061] u(t)=U sd (t)cos(θ)-U sq (t)sin(θ)

[0062] =U1(t)cos(θ+θ1(t))

[0063]

[0064] From the above formula, we can see that the amplitude and phase of the AC voltage can be expressed by the dq axis components of the AC voltage in the synchronous coordinate system. The frequency of the system can be expressed as

[0065]

[0066] With voltage U sd , U sq According to the dynamic characteristics of the marine communication system,

[0067]

[0068] In the formula, It is the output instruction of the d-axis of the MMC controller. is the q-axis output command of the MMC controller, and UC is the equivalent voltage of the capacitor. sd , U sq It is a division relationship, so the capacitor voltage has a relatively small impact on the frequency. When a wind farm fails, the bus voltage is impacted and deviates from the command value. At this time, the MMC controller will react quickly to maintain the d-axis and q-axis voltages. The transient response of the controller will have a dominant influence on the frequency dynamics of the output voltage. Therefore, the system frequency can be controlled from the perspective of MMC controller optimization.

[0069] That is, in the embodiment of the present disclosure, the voltage controller can be controlled to generate corresponding voltage control instructions according to the frequency fluctuation value and the target integral value, thereby achieving frequency fluctuation suppression of the AC system of the offshore wind farm.

[0070] In this embodiment, by determining the real-time frequency value of the AC system of the offshore wind farm, determining the frequency fluctuation value between the real-time frequency value and the preset frequency value, processing the frequency fluctuation value based on the frequency loop, and obtaining a target integral value, wherein the frequency loop belongs to the AC system of the offshore wind farm, and according to the frequency fluctuation value and the target integral value, controlling the voltage controller to generate a voltage control instruction, wherein the voltage controller is used to control the part of the AC voltage of the AC system of the offshore wind farm that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value, thereby, the frequency loop can be introduced to correct the instruction value of the voltage controller, thereby effectively improving the suppression effect of the system frequency fluctuation, and improving the safety and stability of the system.

[0071] Figure 2 It is a flow chart of a method for suppressing frequency fluctuations of an offshore wind farm AC system proposed in another embodiment of the present disclosure.

[0072] like Figure 2 As shown, the frequency fluctuation suppression method of the offshore wind farm AC system includes:

[0073] S201: Determine a real-time frequency value of an AC system of an offshore wind farm.

[0074] S202: Determine a frequency fluctuation value between a real-time frequency value and a preset frequency value.

[0075] S203: Process the frequency fluctuation value based on the frequency loop to obtain a target integral value.

[0076] The description of S201 - S203 can be specifically referred to the above embodiment, which will not be repeated here.

[0077] S204: Determine a first comparison result between the frequency fluctuation value and a preset threshold, wherein the preset threshold is zero.

[0078] The first comparison result may refer to a difference between the frequency fluctuation value and a preset threshold.

[0079] In the disclosed embodiment, when the first comparison result is greater than zero, it indicates that the system frequency at this time is higher than the rated frequency of the system. When the first comparison result is less than zero, it indicates that the system frequency at this time is lower than the rated frequency of the system.

[0080] Therefore, in the embodiment of the present disclosure, when determining the first comparison result between the frequency fluctuation value and the preset threshold, the obtained first comparison result can accurately indicate the abnormal situation of the current system frequency.

[0081] S205: Determine a second comparison result between the target integral value and the preset threshold.

[0082] The second comparison result may be used to indicate whether the target integral value is positive or negative.

[0083] In the embodiment of the present disclosure, when the second comparison result between the target integral value and the preset threshold is determined, an accurate execution basis can be provided for the subsequent control of the voltage controller to generate a voltage control instruction.

[0084] S206: Controlling a voltage controller to generate a voltage control instruction according to the first comparison result and the second comparison result.

[0085] In the embodiment of the present disclosure, when controlling the voltage controller to generate a voltage control instruction based on the first comparison result and the second comparison result, it can be based on a pre-trained machine learning model, or it can be based on a method combining numbers and shapes, and there is no limitation on this.

[0086] That is to say, in the embodiment of the present disclosure, after obtaining the frequency fluctuation value and the target integral value, a first comparison result between the frequency fluctuation value and a preset threshold value can be determined, wherein the preset threshold value is zero, and a second comparison result between the target integral value and the preset threshold value can be determined. According to the first comparison result and the second comparison result, the voltage controller is controlled to generate a voltage control instruction. Thus, the corresponding voltage control instruction can be flexibly generated based on the first comparison result and the second comparison result to ensure the adaptability between the obtained voltage control instruction and the personalized application scenario.

[0087] In this embodiment, by determining a first comparison result between the frequency fluctuation value and a preset threshold, wherein the preset threshold is zero, a second comparison result between the target integral value and the preset threshold is determined, and according to the first comparison result and the second comparison result, the voltage controller is controlled to generate a voltage control instruction. Thus, corresponding voltage control instructions can be flexibly generated based on the first comparison result and the second comparison result to ensure the adaptability between the obtained voltage control instructions and personalized application scenarios.

[0088] A method for suppressing frequency fluctuations in an offshore wind farm AC system is also proposed in an embodiment of the present disclosure. When a voltage controller is controlled to generate a voltage control instruction based on a first comparison result and a second comparison result, if the first comparison result indicates that the frequency fluctuation value is greater than zero, and the second comparison result indicates that the target integral value is greater than zero, then the voltage controller is controlled to generate a first voltage instruction value, wherein the first voltage instruction value is less than zero.

[0089] A method for suppressing frequency fluctuations in an offshore wind farm AC system is also proposed in an embodiment of the present disclosure. When a voltage controller is controlled to generate a voltage control instruction based on a first comparison result and a second comparison result, if the first comparison result indicates that the frequency fluctuation value is less than zero, and the second comparison result indicates that the target integral value is less than zero, then the voltage controller is controlled to generate a second voltage instruction value, wherein the second voltage instruction value is greater than zero, and the differential value of the second voltage instruction value is greater than zero.

[0090] A method for suppressing frequency fluctuations in an offshore wind farm AC system is also proposed in an embodiment of the present disclosure. When a voltage controller is controlled to generate a voltage control instruction based on a first comparison result and a second comparison result, if the first comparison result indicates that the frequency fluctuation value is greater than zero, and the second comparison result indicates that the target integral value is less than zero, the voltage controller is controlled to generate a third voltage instruction value, wherein the third voltage instruction value is greater than zero, and the differential value of the third voltage instruction value is less than zero.

[0091] A method for suppressing frequency fluctuations in an offshore wind farm AC system is also proposed in an embodiment of the present disclosure. When a voltage controller is controlled to generate a voltage control instruction based on a first comparison result and a second comparison result, if the first comparison result indicates that the frequency fluctuation value is less than zero, and the second comparison result indicates that the target integral value is greater than zero, the voltage controller is controlled to generate a fourth voltage instruction value, wherein the fourth voltage instruction value is less than zero, and the differential value of the fourth voltage instruction value is greater than zero.

[0092] For example, Figure 3 As shown, Figure 3 : is a schematic diagram of the structure of the offshore converter station frequency control system proposed in the present disclosure. In steady state and transient state, since the q-axis voltage control command is always 0, U sq The size is always around 0, U sdMuch larger than U sq , the frequency fluctuation value can satisfy:

[0093]

[0094] Further

[0095] ∫Δf(t)dt∝U sq (t)

[0096] From the above formula, we can see that the integral of the frequency fluctuation is related to U sq The output of the frequency loop is the integral value of the frequency fluctuation, which will be fed back as the command value of the q-axis of the voltage loop controller, as shown in the following formula.

[0097] U f-control =0-(kpf+kif / s)∫(f(t)-f0)dt

[0098] =0-(kpf+kif / s)[∫f(t)dt-θ]

[0099] Among them, the control logic of the frequency controller is as follows:

[0100] When the frequency increases Δf>0 and the integral result is greater than 0, U q_fref <0, which reduces Δf;

[0101] When the frequency decreases Δf<0 and the integral result is less than 0, U q_fref >0 and U′ q f fief >0, which increases Δf;

[0102] When the frequency increases Δf>0 and the integral result is less than 0, U q-fref >0 and U′ q-fief <0, which reduces Δf;

[0103] When the frequency decreases Δf<0 and the integral result is greater than 0, U q_fref <0 and make U' q_fref >0, making Δf increase.

[0104] Figure 4 It is a structural schematic diagram of a frequency fluctuation suppression device for an offshore wind farm AC system proposed in one embodiment of the present disclosure.

[0105] like Figure 4 As shown, the frequency fluctuation suppression device 40 of the offshore wind farm AC system includes:

[0106] The first determination module 401 is used to determine the real-time frequency value of the AC system of the offshore wind farm;

[0107] The second determination module 402 is used to determine the frequency fluctuation value between the real-time frequency value and the preset frequency value;

[0108] A processing module 403 is used to process the frequency fluctuation value based on the frequency loop to obtain a target integral value, wherein the frequency loop belongs to an AC system of an offshore wind farm;

[0109] The control module 404 is used to control the voltage controller to generate a voltage control instruction according to the frequency fluctuation value and the target integral value, wherein the voltage controller is used to control the part of the AC voltage of the AC system of the offshore wind farm that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value.

[0110] It should be noted that the aforementioned explanation of the frequency fluctuation suppression method of the offshore wind farm AC system is also applicable to the frequency fluctuation suppression device of the offshore wind farm AC system of this embodiment, and will not be repeated here.

[0111] In this embodiment, by determining the real-time frequency value of the AC system of the offshore wind farm, determining the frequency fluctuation value between the real-time frequency value and the preset frequency value, processing the frequency fluctuation value based on the frequency loop, and obtaining a target integral value, wherein the frequency loop belongs to the AC system of the offshore wind farm, and according to the frequency fluctuation value and the target integral value, controlling the voltage controller to generate a voltage control instruction, wherein the voltage controller is used to control the part of the AC voltage of the AC system of the offshore wind farm that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value, thereby, the frequency loop can be introduced to correct the instruction value of the voltage controller, thereby effectively improving the suppression effect of the system frequency fluctuation, and improving the safety and stability of the system.

[0112] Figure 5 A block diagram of an exemplary computer device suitable for implementing embodiments of the present disclosure is shown. Figure 5 The computer device 12 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0113] like Figure 5 As shown, the computer device 12 is in the form of a general-purpose computing device. The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0114] The bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus and Peripheral Component Interconnection (PCI) bus.

[0115] The computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0116] The memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 5 Not shown, often called a "hard drive").

[0117] although Figure 5 Not shown in the figure, a disk drive for reading and writing a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing a removable non-volatile optical disk (e.g., a compact disc read only memory (hereinafter referred to as: CD-ROM), a digital versatile disc read only memory (hereinafter referred to as: DVD-ROM) or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present disclosure.

[0118] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described in the present disclosure.

[0119] The computer device 12 may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), one or more devices that enable a human body to interact with the computer device 12, and / or any device that enables the computer device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed via an input / output (I / O) interface 22. In addition, the computer device 12 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 20. As shown, the network adapter 20 communicates with other modules of the computer device 12 via a bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0120] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28 , for example, implementing the frequency fluctuation suppression method of the offshore wind farm AC system mentioned in the above-mentioned embodiment.

[0121] In order to implement the above embodiments, the present disclosure also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the frequency fluctuation suppression method of the offshore wind farm AC system proposed in the above embodiments of the present disclosure is implemented.

[0122] In order to implement the above embodiments, the present disclosure further proposes a computer program product. When the instruction processor in the computer program product is executed, the frequency fluctuation suppression method of the offshore wind farm AC system proposed in the above embodiments of the present disclosure is executed.

[0123] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0124] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0125] It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" is two or more.

[0126] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0127] It should be understood that the various parts of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0128] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0129] In addition, each functional unit in each embodiment of the present disclosure may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0130] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0131] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0132] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A method for suppressing frequency fluctuations of an AC system of an offshore wind farm, characterized in that: include: Determine the real-time frequency value of the AC system of the offshore wind farm; Determining a frequency fluctuation value between the real-time frequency value and a preset frequency value; Processing the frequency fluctuation value based on the frequency loop to obtain a target integral value; According to the frequency fluctuation value and the target integral value, a voltage controller is controlled to generate a voltage control instruction, wherein the voltage controller is used to control the part of the AC voltage of the offshore wind farm AC system that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value.

2. The method according to claim 1, characterized in that The step of controlling a voltage controller to generate a voltage control instruction according to the frequency fluctuation value and the target integral value comprises: Determine a first comparison result between the frequency fluctuation value and a preset threshold, wherein the preset threshold is zero; Determine a second comparison result between the target integral value and the preset threshold value; According to the first comparison result and the second comparison result, the voltage controller is controlled to generate the voltage control instruction.

3. The method according to claim 2, characterized in that The step of controlling the voltage controller to generate the voltage control instruction according to the first comparison result and the second comparison result includes: If the first comparison result indicates that the frequency fluctuation value is greater than zero, and the second comparison result indicates that the target integral value is greater than zero, the voltage controller is controlled to generate a first voltage command value, wherein the first voltage command value is less than zero.

4. The method according to claim 2, characterized in that The step of controlling the voltage controller to generate the voltage control instruction according to the first comparison result and the second comparison result includes: If the first comparison result indicates that the frequency fluctuation value is less than zero, and the second comparison result indicates that the target integral value is less than zero, the voltage controller is controlled to generate a second voltage command value, wherein the second voltage command value is greater than zero, and the differential value of the second voltage command value is greater than zero.

5. The method according to claim 2, characterized in that The step of controlling the voltage controller to generate the voltage control instruction according to the first comparison result and the second comparison result includes: If the first comparison result indicates that the frequency fluctuation value is greater than zero, and the second comparison result indicates that the target integral value is less than zero, the voltage controller is controlled to generate a third voltage command value, wherein the third voltage command value is greater than zero, and the differential value of the third voltage command value is less than zero.

6. The method according to claim 2, characterized in that The step of controlling the voltage controller to generate the voltage control instruction according to the first comparison result and the second comparison result includes: If the first comparison result indicates that the frequency fluctuation value is less than zero, and the second comparison result indicates that the target integral value is greater than zero, the voltage controller is controlled to generate a fourth voltage command value, wherein the fourth voltage command value is less than zero, and the differential value of the fourth voltage command value is greater than zero.

7. A frequency fluctuation suppression device for an AC system of an offshore wind farm, characterized in that: include: A first determination module is used to determine a real-time frequency value of an AC system of an offshore wind farm; A second determination module, used to determine a frequency fluctuation value between the real-time frequency value and a preset frequency value; A processing module, used for processing the frequency fluctuation value based on the frequency loop to obtain a target integral value; A control module is used to control a voltage controller to generate a voltage control instruction according to the frequency fluctuation value and the target integral value, wherein the voltage controller is used to control the part of the AC voltage of the offshore wind farm AC system that is in phase with the grid voltage after Park transformation, and the voltage control instruction is used to reduce the difference between the real-time frequency value and the preset frequency value.

8. A computer device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: in, The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The invention comprises a computer program which, when executed by a processor, implements the steps of the method according to any one of claims 1 to 6.

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