Method and device for controlling surplus power absorbed by offshore wind power

Abstract

The invention discloses a control method for offshore wind power absorption surplus power, and the method comprises the steps: determining a power collection submarine cable with energy consumption input according to the calculated surplus power and the output power of the power collection submarine cable when a receiving end AC side fault occurs in an offshore wind power flexible DC system, namely, a land AC power grid has a fault; therefore, the energy consumption device in the wind turbine generator connected to the current collection submarine cable is controlled to be directly called to absorb surplus power generated by continuous power generation of the wind turbine generator after a fault, and the energy consumption device in the wind turbine generator can quickly adjust active power output of a fan, so that the active power output of the wind turbine generator invested in energy consumption is quickly reduced; therefore, the surplus power incorporated into the flexible direct current is quickly eliminated, a centralized direct current energy consumption device does not need to be independently installed, and the investment cost is reduced while the fault regulation efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coordinated control of flexible DC systems for offshore wind power, and particularly relates to a control method and device for absorbing surplus power in offshore wind power. Background Art

[0002] With the continuous increase in power consumption and the development of wind power technology, the development of offshore wind power has received attention in the power technology industry. In an offshore wind power system, when a fault occurs in the receiving-end AC system, the output power of the receiving-end converter station decreases, and the wind farm will partially or completely lose its connection with the receiving-end AC system. At this time, the output power of the wind turbines is difficult to respond quickly and continues to generate electricity, resulting in surplus power. If the surplus power is maintained all the time, the DC voltage will continue to rise until the system trips, threatening the safe operation of equipment and the system.

[0003] To avoid causing system tripping, the current solution is to configure a centralized DC energy-consuming device on the DC side of the onshore converter station. However, when a DC fault occurs in the system, the centralized DC energy consumption will be short-circuited, and the surplus power will cause the power to be unable to be balanced through the configured centralized DC energy-consuming device, resulting in system tripping. Summary of the Invention

[0004] Based on this, the present invention aims to propose a control method and device for absorbing surplus power in offshore wind power, which calls the energy-consuming devices inside the wind turbines to absorb surplus power when a fault occurs, so as to overcome the problems in the above-mentioned prior art.

[0005] In a first aspect, the present invention provides a control method for absorbing surplus power in offshore wind power, including:

[0006] Calculating the surplus power after a fault occurs in the onshore AC grid;

[0007] Determining the collector submarine cables for energy consumption input according to the surplus power and the output power of each collector submarine cable;

[0008] Controlling the wind turbines connected to the collector submarine cables for energy consumption input to turn on the energy-consuming devices inside the wind turbines until the onshore AC grid fault is restored. When the onshore AC grid fault is restored, controlling the wind turbines that have turned on the energy-consuming devices to exit the energy consumption input according to the set exit rules.

[0009] Further, calculating the surplus power after a fault occurs in the onshore AC grid includes:

[0010] Collecting the AC voltage of the onshore converter station after a fault occurs in the onshore AC grid;

[0011] Calculating the available transmitted active power according to the AC voltage of the onshore converter station, and calculating the surplus power as follows according to the available transmitted active power and the current transmitted power:

[0012] ,

[0013] Among them, represents the surplus power, represents the current transmission power, represents the active power that can be transmitted, represents the positive-sequence voltage amplitude of the AC voltage of the onshore converter station, represents the d-axis current limit amplitude of the onshore converter station.

[0014] Furthermore, the collector submarine cables for energy consumption input are determined according to the surplus power and the output power of each collector submarine cable, including:

[0015] Calculate the output power of each collector submarine cable before the onshore AC power grid fails according to the output power of the wind turbines connected to the collector submarine cable;

[0016] Based on the surplus power and the output power of each collector submarine cable, determine the candidate collector submarine cables that meet the preset input conditions among the collector submarine cables;

[0017] Determine the collector submarine cables for energy consumption input from the candidate collector submarine cables according to the set input rules.

[0018] Furthermore, the preset input conditions include:

[0019] The output power of the collector submarine cable satisfies the following relationship:

[0020] ,

[0021] Among them, represents the output power of the l-th collector submarine cable before the onshore AC power grid fails, represents the surplus power, represents the floor operation.

[0022] Furthermore, determining the collector submarine cables for energy consumption input from the candidate collector submarine cables according to the set input rules includes:

[0023] Sort the candidate collector submarine cables in descending order according to their output power, and select at least one candidate collector submarine cable for energy consumption input in sequence according to the surplus power, so that the collector submarine cables for energy consumption input can completely absorb the surplus power.

[0024] Furthermore, calculating the output power of each collector submarine cable before the onshore AC power grid fails according to the output power of the wind turbines connected to the collector submarine cable includes:

[0025] Determine the wind turbines that meet the energy consumption input conditions of the wind turbines connected to each collector submarine cable, and record them as available wind turbines;

[0026] Calculate the output power of the collector submarine cable according to the output powers of all available wind turbines connected to each collector submarine cable.

[0027] Further, the energy-consuming devices included in the wind turbines connected to the collector submarine cable with energy-consuming input control include:

[0028] Transmit an energy-consuming input control instruction to the wind turbine, so that the wind turbine starts to lock the converter and inputs the energy-consuming device inside the wind turbine to absorb power.

[0029] Further, transmitting an energy-consuming input control instruction to the wind turbine, so that the wind turbine starts to lock the converter and inputs the energy-consuming device inside the wind turbine to absorb power includes:

[0030] Transmit a converter locking control instruction and an energy-consuming device input control instruction to the wind turbine, so that the wind turbine starts to lock the converter according to the converter locking control instruction and inputs the energy-consuming device inside the wind turbine to absorb power according to the energy-consuming device input control instruction.

[0031] Further, setting the exit rule includes the exit sequence of the collector submarine cable input and exit.

[0032] In a second aspect, the present invention provides a control device for absorbing surplus power of offshore wind power, including:

[0033] A surplus power calculation module, configured to calculate the surplus power after a failure occurs in the onshore AC grid;

[0034] A collector submarine cable determination module, configured to determine the collector submarine cable with energy-consuming input according to the surplus power and the output powers of each collector submarine cable;

[0035] An energy-consuming input control module, configured to control the wind turbines connected to the collector submarine cable with energy-consuming input to input the energy-consuming devices inside the wind turbines until the onshore AC grid fault is restored, and when the onshore AC grid fault is restored, control the wind turbines with the energy-consuming devices already input to exit the energy-consuming input according to the set exit rule.

[0036] In a third aspect, the present invention provides an electronic device, including a memory storing computer-executable instructions and a processor, and when the computer-executable instructions are executed by the processor, the device executes each step of the control method for absorbing surplus power of offshore wind power provided in the first aspect.

[0037] In a fourth aspect, the present invention provides a readable storage medium, storing a computer-executable program, and when the program is executed, each step of the control method for absorbing surplus power of offshore wind power provided in the first aspect can be implemented.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention provides a control method for absorbing surplus power in offshore wind power. When a fault occurs on the receiving-end AC side of the offshore wind power flexible DC system, that is, when a fault occurs in the onshore AC power grid, the collector submarine cable for energy consumption is determined according to the calculated surplus power and the output power of the collector submarine cable, so as to control the direct call of the energy-consuming device inside the wind turbine connected to the collector submarine cable, so as to absorb the surplus power generated by the wind turbine continuously generating electricity after the fault. The energy-consuming device inside the wind turbine can quickly adjust the active power output of the fan, so that the active power output of the wind turbine with energy consumption input is quickly reduced, so as to quickly eliminate the surplus power attributed to the flexible DC, without the need to install a centralized DC energy-consuming device separately, improving the fault regulation efficiency while reducing the investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0041] Figure 1 is the architecture diagram of the offshore wind power flexible DC transmission system provided by the embodiment of the present invention;

[0042] Figure 2 is the implementation flowchart of the control method for absorbing surplus power in offshore wind power provided by the embodiment of the present invention;

[0043] Figure 3 is the structure diagram of the control device for absorbing surplus power in offshore wind power provided by the embodiment of the present invention;

[0044] Figure 4 is the architecture diagram of the electronic device provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] As Figure 1 shown, it schematically shows a typical offshore wind power flexible DC transmission system. Each offshore wind turbine is connected to an offshore converter station via an AC submarine cable. The offshore converter station lands via a DC submarine cable and is connected to an onshore converter station, and the onshore converter station is connected to the onshore industrial frequency power grid.

[0047] Specifically, a back-to-back AC-DC-AC converter is configured inside each wind turbine generator, that is, the wind turbine generator is connected to an AC-DC converter and a DC-AC converter in sequence, such as Figure 1 the illustrated AC-to-DC module and DC-to-AC module. A fan DC energy consumption device is provided inside each converter, which is generally used to absorb the active power generated by the fan after a grounding fault occurs on the offshore AC side, and assist the fan to achieve AC fault ride-through.

[0048] During the power transmission and distribution process, each wind turbine generator communicates quickly with the offshore converter station through a dedicated optical fiber channel in the AC submarine cable. The control device issues a control command to call the energy consumption device to each wind turbine generator through this optical fiber channel. At the same time, all fans collect their own operating status parameters and send them to the offshore converter station in real time through the optical fiber channel.

[0049] The following embodiments of the present invention will provide a control method for absorbing surplus power in offshore wind power. When an AC fault occurs in the large power unit with industrial frequency at the onshore receiving end, the energy consumption device inside the wind turbine generator is directly called to absorb the surplus power, and the distributed energy consumption method is adopted to avoid system instability caused by centralized energy consumption.

[0050] Refer to Figure 2 , an embodiment of the present invention provides a control method for absorbing surplus power in offshore wind power, including the following steps:

[0051] Step S210. Calculate the surplus power after a fault occurs in the onshore AC power grid.

[0052] The surplus power calculated in this step mainly refers to the electric energy that, due to a fault in the onshore AC power grid, causes the wind turbine generator to be disconnected from the grid or the power transmission to be blocked, the wind turbine continues to generate power due to the input of wind energy but cannot be sent out of the grid, and exceeds the system's temporary storage capacity. This part of the power that cannot be sent out accumulates on the DC side inside the wind turbine generator and needs to be disposed of in time to avoid safety problems such as rapid increase in DC voltage and triggering of protection tripping.

[0053] Specifically, when a fault occurs in the onshore AC power grid, the monitoring system will detect typical fault characteristics such as voltage dip, current anomaly, and frequency deviation on the AC side of the converter station or the onshore bus. Such signals are quickly collected and transmitted from the onshore converter station or the main control system to the offshore control center.

[0054] The active power that can be continuously transmitted by the flexible DC is related to the positive-sequence voltage amplitude of the onshore power frequency large grid. After an AC fault occurs in the onshore receiving-end power frequency large grid, the positive-sequence voltage amplitude of the AC voltage of the onshore converter station can be detected through the configured voltage measuring device, the active power that can be transmitted can be calculated, and the current transmission power of the entire flexible DC transmission system can be determined. If the active power that can be transmitted is less than the current transmission power, there is surplus power that needs to be absorbed. Otherwise, it is considered that the system can continue to transmit all the current active power without calling the energy-consuming device.

[0055] In some embodiments, the total power generation of the current offshore wind farm can be used as the calculated value of the current transmission power.

[0056] In a further embodiment, the calculation process of the surplus power is as follows:

[0057]

[0058] Among them, represents the surplus power, represents the current transmission power, represents the active power that can be transmitted, represents the positive-sequence voltage amplitude of the AC voltage of the onshore converter station, represents the d-axis current limit amplitude of the onshore converter station.

[0059] Step S220. Determine the collector submarine cables for which energy consumption is to be input according to the surplus power and the output power of each collector submarine cable.

[0060] Specifically, the collector submarine cable refers to the AC cable connecting the offshore wind turbines and the offshore converter station. In an offshore wind farm, multiple wind turbines are usually connected to the same collector submarine cable, which is the standard design mode of the current offshore wind power collection system, aiming to improve the collection efficiency, reduce the laying cost, reduce the cable length and the number of onshore equipment.

[0061] In this step, the energy consumption control system can obtain the output power of all collector submarine cables in real time, and use the power distribution algorithm to allocate the required energy consumption to some or all of the submarine cables. The goal is to evenly distribute the total required energy consumption within the energy range allowed by each submarine cable.

[0062] Furthermore, the determination strategy for the collector submarine cables for which energy consumption is to be input can be based on the load sharing priority, that is, preferentially select the collector submarine cables with a low load rate and a high power redundancy; or, select according to the balance of the wind turbine distribution to avoid the concentration of surplus power on a single submarine cable resulting in local overheating or dynamic instability; or, preferentially select the proximal cables with good stability according to the health status of the submarine cables to ensure the transmission efficiency of the energy consumption instruction.

[0063] Furthermore, step S220 includes:

[0064] Step S221. Calculate the output power of each collector submarine cable before a fault occurs in the onshore AC power grid according to the output power of the wind turbines connected to the collector submarine cable.

[0065] This step monitors the transmission power of the AC collector submarine cables at sea in real time. The output power of a collector submarine cable refers to the total active power transmitted through it to the offshore converter station or grid connection interface at the moment before the fault, usually in kW or MW. The output power of a wind turbine is the instantaneous active power output from the wind turbine to the collector network after being controlled by the converter.

[0066] Under normal operating conditions, the operating data of the offshore wind turbines can be uploaded to the main control system of the offshore converter station in real time through the data monitoring and control system and the synchronous measurement unit. In some embodiments, the main control system can obtain the stable output power value of each wind turbine under normal conditions within a sliding time window before the fault occurs, and sum up the powers of the wind turbines connected to the same collector submarine cable to obtain the output power of each collector submarine cable.

[0067] Step S222. Based on the surplus power and the output power of each collector submarine cable, determine the candidate collector submarine cables that meet the preset input conditions among the collector submarine cables.

[0068] The preset input conditions in this step mainly refer to criteria such as power, current, voltage, and safety margin set to ensure the thermal stability, dynamic response ability, and control safety of the submarine cable and the wind turbine. The collector submarine cables that can be used for energy consumption input need to be safely connected to the energy-consuming device and be able to withstand the control response.

[0069] Specifically, this step calculates the output power of the collector submarine cable before the onshore AC fault occurs, and selects the qualified collector submarine cables as candidate collector submarine cables according to the following criteria:

[0070] The output power of the collector submarine cable needs to satisfy the following relationship:

[0071]

[0072] where represents the output power of the l-th collector submarine cable before the onshore AC power grid fault occurs, represents the surplus power, represents the floor operation. The wind turbines connected to other unqualified collector submarine cables remain in normal operation.

[0073] Step S223. Determine the collector submarine cables for energy consumption input among the candidate collector submarine cables according to the set input rules.

[0074] The setting input rules for this step refer to the power distribution algorithm, priority rules or sorting mechanism formulated according to the overall control strategy and operation safety objectives of the wind farm, which are used to guide the selection and sorting execution of specific switching objects in the candidate collector submarine cables.

[0075] Furthermore, equal - proportion power distribution can be selected to distribute the surplus power proportionally according to the output power of the collector submarine cables, so as to ensure fair power sharing and avoid excessive local pressure. This input method will require more collector submarine cables.

[0076] Furthermore, the collector submarine cables can be sorted according to their input priorities based on the output power. The collector submarine cables with larger power are preferentially selected for input to reduce the energy - consumption input cost. Specifically, it includes sorting the candidate collector submarine cables in descending order of output power, and sequentially selecting at least one collector submarine cable for energy - consumption input according to the surplus power, so that the cumulative energy - consumption power of the collector submarine cables for energy - consumption input is ≥ the surplus power.

[0077] Furthermore, before determining the candidate collector submarine cables, the availability of the energy - consumption devices inside the wind turbines needs to be considered. Specifically, when calculating the output power of the collector submarine cables, only the output power of the wind turbines that meet the energy - consumption input conditions of the wind turbine units can be considered. In some embodiments, the availability of the energy - consumption devices can also not be considered first. When screening the candidate collector submarine cables, the unavailable wind turbines are excluded first, and then the actual output power of the collector submarine cables is determined.

[0078] Step S230. Control the wind turbine units connected to the collector submarine cables for energy - consumption input to turn on the energy - consumption devices inside the wind turbine units until the onshore AC grid fault is restored. When the onshore AC grid fault is restored, control the wind turbine units that have turned on the energy - consumption devices to withdraw from the energy - consumption input according to the set withdrawal rules.

[0079] Specifically, the energy - consumption devices inside the wind turbine units are energy dissipation devices installed on the DC bus or AC side of the converter inside the wind turbine. Usually, they are high - speed thyristor - controlled resistor groups or controllable resistor load units, which are used to temporarily absorb the excess electric energy. The control system of the offshore converter station sends an energy - consumption input control instruction to the wind turbine units under the selected collector submarine cables. After the controller of the wind turbine body receives the control instruction, it switches the converter control state to "power - limit + energy - consumption mode". The excess power is no longer sent out, but is introduced into the energy - consumption branch and converted into heat. At the same time, the control system maintains the stability of the DC bus voltage to prevent the wind turbine from overspeeding. The restoration signal of the onshore AC system is sent from the onshore converter station to the control system of the offshore converter station. When the control system of the offshore converter station determines that the system can be grid - connected, it controls the start of the energy - consumption withdrawal process, so that the wind turbine units that have turned on the energy - consumption devices withdraw from the energy - consumption input, and the output power of the wind turbines returns to the normal state.

[0080] When the power collection cable is determined to need energy input, the control system of the offshore converter station will simultaneously issue energy input control instructions to all wind turbines on the same power collection cable. When the power collection cable needs to be exited, energy exit control instructions will be simultaneously issued to all wind turbines on the same power collection cable.

[0081] Furthermore, the energy consumption input control instruction includes a converter locking control instruction and an energy consumption device input control instruction, so that the wind turbine starts to lock the DC-AC converter according to the converter locking control instruction, and inputs the energy consumption device inside the wind turbine for power absorption according to the energy consumption device input control instruction.

[0082] Specifically, converter blocking refers to the termination of the converter control link inside the wind turbine, so that it stops the normal grid-connected power output and closes the electrical linkage with the grid. After the wind turbine controller receives the converter blocking control command, it first executes the grid-side converter (i.e. Figure 1 The DC to AC module (shown in the figure) is disconnected from the grid and the grid-connected interface is disconnected; then, the voltage and current modulation control inside the converter is stopped, and the converter enters the bypass state or high-resistance state, and at the same time, the normal load regulation loop with the bus capacitor is cut off to ensure that all subsequent energy is transferred to the energy-consuming device, so that the output power of the wind turbine drops to 0 in a short time. Furthermore, the converter is short-term locked, for example, the lockout time is 10ms.

[0083] After the wind turbine controller activates the energy consumption device inside the wind turbine according to the energy consumption device activation control instruction, the wind turbine transmission power will always remain at 0, realizing the on-site dissipation of surplus power after an onshore AC failure occurs.

[0084] Furthermore, after the fault of the onshore AC system is eliminated, in order to make the wind turbines exit the energy consumption state safely, stably and in stages and gradually release the converter lock, it is necessary to design an exit control strategy with delay, judgment and graded action capabilities to avoid all wind turbines being connected to the grid at the same time, resulting in current shocks, and local voltage surges causing secondary fluctuations. Furthermore, the exit rules are set to be the exit order of the collection submarine cable. It can be a step-by-step exit according to the transmission power of the collection submarine cable, or it can be exited in sequence according to the order of entry, or it can be determined according to the temperature change of the energy consumption device inside the wind turbine. For example, the wind turbine with a higher temperature of the energy consumption device is released first, and when exiting, the collection submarine cable that has been put into energy consumption can be exited in sequence according to the set time interval.

[0085] Furthermore, in order to avoid erroneous control instructions and improve the reliability of instructions issued to the wind turbine to call the energy-consuming device, when calculating the surplus power, in addition to detecting the positive-sequence voltage amplitude that drops after the AC side fault, it is also necessary to detect whether the DC voltage amplitude on the DC side exceeds a certain threshold. That is, after confirming the presence of surplus power, the transmission energy consumption input control instruction can be issued to the wind turbine.

[0086] The present invention will be further described below through a specific implementation scenario.

[0087] After a fault occurs on the onshore receiving AC side, the measuring device detects a voltage dip and sends a voltage command to the receiving-end DC control and protection device. The receiving-end DC control and protection device generates an AC fault signal and calculates the surplus power to be absorbed based on the positive-sequence voltage amplitude and the transmitted power before the fault.

[0088] The control and protection device of the onshore converter station sends the above information to the control and protection device of the offshore converter station via the inter-station optical fiber communication device of the converter station. At the same time, the control and protection device of the offshore converter station receives the power information uploaded by all offshore wind turbines and the status of the energy-consuming devices via the dedicated optical fiber communication device inside the submarine cable. The offshore station control and protection device ranks the wind turbines in real time based on the status of the energy-consuming devices and the power information. It notifies the offshore station to monitor the magnitude of the DC voltage. When it receives the surplus power information and the AC fault signal sent by the onshore station and detects that the DC voltage is greater than the action threshold, it determines the collector submarine cable that needs to input energy consumption according to the surplus power, and transmits the converter locking control command and the energy-consuming device input control command to the control and protection devices inside all the wind turbines that need to input energy consumption via the optical fiber channel inside the submarine cable. After receiving the command, the control and protection device inside the wind turbine locks the grid-side converter and inputs the energy-consuming device inside it to absorb the surplus power.

[0089] After the control and protection device of the onshore converter station detects that the onshore receiving AC fault has disappeared, it can resume normal power transmission and send an energy-consuming device withdrawal control command to the control and protection device of the offshore converter station through the same communication channel. After receiving the command, the control and protection device of the offshore converter station sends a converter unlocking control command and an energy-consuming device withdrawal command to the wind turbines that have input the energy-consuming devices.

[0090] The above embodiments provide a control method for absorbing surplus power in offshore wind power. When a fault occurs on the receiving AC side of the offshore wind power flexible DC system, that is, when a fault occurs in the onshore AC power grid, the collector submarine cable for energy consumption input is determined according to the calculated surplus power and the output power of the collector submarine cable, so as to control the energy-consuming devices inside the wind turbines directly connected to the collector submarine cable to absorb the surplus power generated by the wind turbines continuously generating electricity after the fault. The energy-consuming devices inside the wind turbines can quickly adjust the active power output of the wind turbines, so that the active power output of the wind turbines with energy consumption input decreases rapidly, thereby quickly eliminating the surplus power incorporated into the flexible DC. There is no need to install a centralized DC energy-consuming device separately, which improves the fault regulation efficiency and reduces the investment cost at the same time.

[0091] The above-disclosed method can be implemented by devices in various forms. Therefore, the present invention also discloses a control device corresponding to the above method, and specific embodiments are given below for detailed description.

[0092] As shown Figure 3 in the figure, an embodiment of the present invention provides a control device for absorbing surplus power in offshore wind power, including:

[0093] A surplus power calculation module 302, configured to calculate the surplus power after a failure occurs in the onshore AC grid;

[0094] A collector submarine cable determination module 303, configured to determine the collector submarine cables for energy consumption input according to the surplus power and the output power of each collector submarine cable;

[0095] An energy consumption input control module 306, configured to control the wind turbines connected to the collector submarine cables for energy consumption input to turn on the energy consumption devices inside the wind turbines until the onshore AC grid fault is restored, and control the wind turbines with the energy consumption devices turned on to exit the energy consumption input according to the set exit rules when the onshore AC grid fault is restored.

[0096] For the device provided by the embodiments of the present application, the implementation principle and the technical effects generated are the same as those of the foregoing method embodiments. For the sake of brief description, for the parts not mentioned in the device embodiments, reference may be made to the corresponding content in the foregoing method embodiments.

[0097] The methods and related devices mentioned in the above embodiments are described with reference to the method flowcharts and / or structural schematic diagrams provided by the embodiments of the present application. Specifically, they can be implemented by computer program instructions for each process and / or block in the method flowchart and / or structural schematic diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in one process Figure 1 one process or multiple processes and / or structural schematic Figure 1 one block or multiple blocks. These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in one process Figure 1 one process or multiple processes and / or structural schematic Figure 1 one block or multiple blocks. These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 one process or multiple processes and / or structural schematic one block or multiple blocks.

[0098] The following embodiments will be described by taking the application of this method to a computer device as an example. It can be understood that the computer device can be any device with computing and processing capabilities, and can be, but is not limited to, a server or a personal laptop computer, etc. In one embodiment, the computer device can be an application server, and the application server can be a server for running an application under test.

[0099] Refer to Figure 4 , which shows a hardware structure block diagram of an electronic device. The electronic device is intended to represent various forms of digital computers, such as, a laptop computer, a desktop computer, a workbench, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, a personal digital processor, a cellular phone, a smart phone, a wearable device, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples and are not intended to limit the implementation of the present application described herein and / or claimed.

[0100] As Figure 4 shown, the electronic device includes: at least one processor 1, at least one communication interface 2, at least one memory 3, and at least one communication bus 4;

[0101] In the embodiments of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 complete mutual communication through the communication bus 4;

[0102] The processor 1 may be a central processing unit CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention, etc.;

[0103] The memory 3 may include a high-speed RAM memory, and may also include a non-volatile memory, etc., such as at least one disk memory;

[0104] Among them, the memory stores a program, and the processor can call the program stored in the memory. The program is used to: implement each processing flow of the aforementioned control method for absorbing surplus power by offshore wind power.

[0105] The embodiments of the present invention also provide a readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements each processing flow of the control solution method for absorbing surplus power by offshore wind power provided by any possible implementation manner of the above embodiments and / or combined embodiments.

[0106] The above embodiments have described the present invention in particular detail with respect to possible scenarios, and those skilled in the art will recognize that the present invention can be practiced through other embodiments. The specific naming of components, the case of terms, attributes, data structures, or any other programming or structural aspects are not mandatory or significant, and the mechanisms or features for implementing the present invention can have different names, forms, or procedures. The system can be implemented through a combination of hardware and software (as described), entirely through hardware elements, or entirely through software elements. The specific division of functions among the various system components described herein is merely exemplary and not mandatory; on the contrary, the functions performed by a single system component can be performed by multiple components, or the functions performed by multiple components can be performed by a single component.

[0107] Those skilled in the art should understand that each step of the above-disclosed method can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Optionally, they can be implemented with program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. Thus, the disclosure of the embodiments of the present invention is not limited to any specific combination of hardware and software.

[0108] These programs executable by the computing device (also referred to as programs, software, software applications, or code) include machine instructions for a programmable processor and can implement these computing programs using high-level procedures and / or object-oriented programming languages and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, device, and / or apparatus (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0109] Certain aspects of the present invention include the process steps and instructions described herein in the form of algorithms. It should be noted that the process steps and instructions of the present invention can be implemented in software, firmware, and / or hardware. When implemented by software, it can be downloaded and thus saved on different platforms used by various operating systems and operated from those platforms.

[0110] Those skilled in the art can understand that the structures shown in the drawings are merely block diagrams of some structures related to the solution of the present application, and do not constitute a limitation on the terminal devices to which the solution of the present application is applied. The specific terminal devices may include more or fewer components than those shown in the figures, or combine some components, or have different component arrangements.

[0111] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "possible design", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for absorbing surplus power of offshore wind power, characterized in that, Including: Calculating the surplus power after a failure occurs in the onshore AC power grid; Determining the collector submarine cables with energy consumption input according to the surplus power and the output power of each collector submarine cable; Controlling the wind turbines connected to the collector submarine cables with energy consumption input to turn on the energy consumption devices inside the wind turbines until the onshore AC power grid fault is restored. When the onshore AC power grid fault is restored, controlling the wind turbines with the energy consumption devices turned on to exit the energy consumption input according to the set exit rules.

2. The method according to claim 1, wherein The calculating the surplus power after the onshore AC power grid fails includes: After the onshore AC power grid fails, collecting the AC voltage of the onshore converter station and the current transmission power of the system; Calculating the active power that can be transmitted according to the AC voltage of the onshore converter station, and calculating the surplus power according to the active power that can be transmitted and the current transmission power of the system as follows: ， Among them, represents the surplus power, represents the current transmission power of the system, represents the active power that can be transmitted, represents the positive sequence voltage amplitude of the AC voltage of the onshore converter station, represents the d-axis current limit amplitude of the onshore converter station.

3. The method according to claim 2, wherein The determining the collector submarine cables with energy consumption input according to the surplus power and the output power of each collector submarine cable includes: Calculating the output power of each collector submarine cable before the onshore AC power grid fails according to the output power of the wind turbines connected to the collector submarine cables; Based on the surplus power and the output power of each collector submarine cable, determining candidate collector submarine cables that meet the preset input conditions among the collector submarine cables; Determining the collector submarine cables with energy consumption input from the candidate collector submarine cables according to the set input rules.

4. The method according to claim 3, characterized in that The preset input conditions include: The output power of the collector submarine cable satisfies the following relationship: ， Among them, represents the output power of the l-th collector submarine cable before a fault occurs in the onshore AC power grid, represents the surplus power, represents the floor operation.

5. The method according to claim 3, wherein The determining the collector submarine cables with energy consumption input from the candidate collector submarine cables according to the set input rules includes: Sorting the candidate collector submarine cables in descending order of their output power, and sequentially selecting at least one candidate collector submarine cable for energy consumption input according to the surplus power, so that the collector submarine cables with energy consumption input can completely absorb the surplus power.

6. The method according to claim 1, characterized in that, The controlling the wind turbines connected to the collector submarine cables with energy consumption input to turn on the energy consumption devices inside the wind turbines includes: Transmitting an energy consumption input control command to the wind turbine, so that the wind turbine starts to lock the converter and turns on the energy consumption devices inside the wind turbine to absorb power.

7. The method according to claim 6, wherein The transmitting an energy consumption input control command to the wind turbine, so that the wind turbine starts to lock the converter and turns on the energy consumption devices inside the wind turbine to absorb power includes: Transmitting a converter locking control command and an energy consumption device input control command to the wind turbine, so that the wind turbine starts to lock the converter according to the converter locking control command and turns on the energy consumption devices inside the wind turbine to absorb power according to the energy consumption device input control command.

8. A control device for absorbing surplus power of an offshore wind farm, characterized in that, Including: A surplus power calculation module, which is used to calculate the surplus power after the onshore AC power grid fails; A collector submarine cable determination module, which is used to determine the collector submarine cables with energy consumption input according to the surplus power and the output power of each collector submarine cable; An energy consumption input control module, which is used to control the wind turbines connected to the collector submarine cables with energy consumption input to turn on the energy consumption devices inside the wind turbines until the onshore AC power grid fault is restored. When the onshore AC power grid fault is restored, controlling the wind turbines with the energy consumption devices turned on to exit the energy consumption input according to the set exit rules.

9. An electronic device, characterized in that, It includes a memory storing computer-executable instructions and a processor, and when the computer-executable instructions are executed by the processor, the device is caused to execute the control method for absorbing surplus power of offshore wind power according to any one of claims 1 to 7.

10. A readable storage medium, characterized in that, It stores a computer-executable program, and when the program is executed, the control method for absorbing surplus power of offshore wind power according to any one of claims 1 to 7 can be implemented.

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