Far sea wind field fan control and protection cooperation method and related equipment

Abstract

The invention discloses a remote sea wind field fan control and protection cooperation method and related equipment, and is applied to a sea wind sending-out grid-connected system. The action information of a protection device is collected in real time, a fault feature set is constructed to judge the fault severity, a high-low penetration control strategy is adopted for a slight fault, and if a serious fault occurs, a switch is triggered to trip, and fan output is reasonably distributed. Wherein the final output upper limit of the fan is comprehensively determined by combining the power transmission channel capacity, the theoretical output limit, the safety margin coefficient and the reactive power regulation capability of the land station. The method effectively solves the problems of slow power regulation response, protection and regulation time sequence mismatch, long steady state recovery time after a fault and the like. By means of rapid and accurate fault judgment, the power regulation response speed is increased; the differential control strategy guarantees stable operation of the fan, and system abnormity is avoided; the output upper limit is determined by integrating multiple factors, the cooperation of protection and power regulation is realized, the steady-state recovery time of the system is remarkably shortened, and safe and stable operation of the far-sea wind field is guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of fan control, and more specifically, to a collaborative method for fan control and protection in a far - sea wind farm and related equipment. Background Art

[0002] In recent years, with the continuous increase in the global demand for clean energy, as an important form of renewable energy, the development process of offshore wind power has been accelerating continuously. When a fault occurs in the transmission line of offshore wind power (including collector lines, busbars, submarine cables, etc.), quickly and accurately identifying the fault, promptly removing the fault, and reasonably adjusting the output of the wind farm according to the change of transmission capacity become the key links to ensure the stable operation of the power system. Otherwise, it is extremely easy to cause a series of serious problems such as system over - voltage, over - current, and equipment overload.

[0003] However, in the existing technology, due to the large single - field installed capacity of offshore wind farms, the long land - sea transmission distance, the complex and variable wind farm topological structure, and the fact that offshore stations mainly rely on automated equipment for unattended operation, there are many defects in the control and protection of the offshore wind power transmission system that need to be solved urgently. First, the power regulation response is slow. When a fault occurs, it is unable to quickly adjust the fan output according to the fault situation, resulting in the system being in an unstable state for a long time. Second, there is a problem of mismatch in the timing sequence between protection action and power regulation. After the protection device acts, the fan power regulation fails to follow up in time, which not only makes it difficult to effectively suppress the impact of the fault but may also cause new safety risks. Third, the time required for the system to reach a steady state after a fault is too long, affecting the stable supply of electricity.

[0004] Therefore, there is an urgent need for a new collaborative method for fan control and protection in a far - sea wind farm, which can effectively solve the above problems and achieve rapid response, precise control, and efficient collaboration for faults in a far - sea wind farm. Summary of the Invention

[0005] This application provides a collaborative method for fan control and protection in a far - sea wind farm and related equipment. By collecting the action information of protection devices in real - time to construct a fault feature set to judge the fault degree and implement a differential control strategy, and at the same time determining the final output upper limit of the fan by comprehensively considering multiple factors, it solves the problems of slow power regulation response, timing mismatch, and long steady - state recovery time after a fault in the existing technology, and ensures the safe and stable operation of the far - sea wind farm.

[0006] A collaborative method for fan control and protection in a far - sea wind farm, which is applied to the offshore wind power transmission and grid - connection system. The method includes:

[0007] Determine the wind farm state and fault information according to the action information of the protection device in the far - sea wind farm transmission line collected in real - time, and establish a fault feature set including the real - time change characteristics of voltage and current;

[0008] If it is determined to be a minor fault based on the fault feature set, a high-low ride-through control strategy is adopted to control the wind turbine to ride through the fault;

[0009] If it is determined to be a severe fault based on the fault feature set, the switch is tripped, and the output of each wind turbine is allocated according to the upper limit of the final output of the wind turbine to achieve the coordination of protection action and power regulation;

[0010] The determination process of the upper limit of the final output of the wind turbine includes:

[0011] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch is tripped, and determine the safe operation limit in combination with the safety margin coefficient;

[0012] According to the reactive power regulation ability of the onshore substation, determine the output limit under reactive power constraints, and comprehensively obtain the upper limit of the final output of the wind turbine based on the safe operation limit.

[0013] Optionally, calculating the transmission channel capacity and the theoretical output limit of the wind farm after the switch is tripped, and determining the safe operation limit in combination with the safety margin coefficient includes:

[0014] Calculate the transmission channel capacity according to the power limit of each transmission section after the switch is tripped;

[0015] Based on the current meteorological conditions and wind turbine parameters, calculate the theoretical output limit of the wind farm;

[0016] Determine the safe operation limit according to the transmission channel capacity, the theoretical output limit of the wind farm and the safety margin coefficient.

[0017] Optionally, the calculation formula for the transmission channel capacity is:

[0018]

[0019] The calculation formula for the safe operation limit is:

[0020]

[0021] Among them, is the transmission channel capacity, is the power limit of the i-th transmission section, n is the number of transmission sections, is the theoretical output limit of the wind farm, K is the safety margin coefficient, is the safe operation limit.

[0022] Optionally, the allocation of the output of each wind turbine according to the upper limit of the final output of the wind turbine includes:

[0023] If the actual output of the current wind turbine does not exceed the upper limit of the final output of the wind turbine, the output of each wind turbine is allocated according to the principle of maximizing economic benefits;

[0024] If the actual output of the current wind turbine exceeds the upper limit of the final output of the wind turbine, the reduction amount of the output is allocated according to the ratio of the rated power of each wind turbine, and the reduction amount of the output of a single wind turbine does not exceed a preset ratio of its rated power.

[0025] Optionally, the principle of maximizing economic benefits is:

[0026]

[0027]

[0028] The calculation formula for the reduction amount of the output is:

[0029]

[0030]

[0031] Wherein, is the revenue coefficient related to the output of the j-th wind turbine, is the cost coefficient related to the output of the j-th wind turbine, is the cost coefficient related to the actual total output of the wind farm, is the cost independent of the output of the wind farm, is the output of the j-th wind turbine, is the reduction amount of the output allocated to the j-th wind turbine, is the actual output of the current wind turbine, m is the number of wind turbines, is the upper limit of the final output of the wind turbine, is the rated power of the j-th wind turbine.

[0032] Optionally, the calculation formula for the output limit under reactive power constraint is:

[0033]

[0034] The determination formula for the upper limit of the final output of the wind turbine is:

[0035]

[0036] Wherein, is the output limit under reactive power constraint, is the safe operation limit, is the grid connection point voltage, X is the equivalent reactance of the system, is the upper limit of reactive power of the onshore substation.

[0037] A coordinated device for wind turbine control and protection in a far-sea wind farm, comprising:

[0038] A fault feature unit, configured to determine the wind farm status and fault information according to the action information of the protection device in the transmission line of the far - sea wind farm collected in real time, and establish a fault feature set including the real - time change characteristics of voltage and current;

[0039] A first control unit, configured to, if it is determined that the current is a minor fault based on the fault feature set, control the fan to cross the fault by using a high - low ride - through control strategy;

[0040] A second control unit, configured to, if it is determined that the current is a severe fault based on the fault feature set, trigger the switch to trip, and allocate the output of each fan according to the upper limit of the final output of the fan, so as to realize the coordination of protection action and power regulation;

[0041] The determination process of the upper limit of the final output of the fan includes:

[0042] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operation limit in combination with the safety margin coefficient;

[0043] Determine the output limit under reactive power constraints according to the reactive power regulation ability of the on - shore station, and comprehensively obtain the upper limit of the final output of the fan based on the safe operation limit.

[0044] A far - sea wind farm fan control and protection coordination device, including a memory and a processor;

[0045] The memory is used to store programs;

[0046] The processor is configured to execute the program to implement each step of the far - sea wind farm fan control and protection coordination method as described in any one of the above.

[0047] A readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, each step of the far - sea wind farm fan control and protection coordination method as described in any one of the above is implemented.

[0048] A computer program product, including a computer program, and when the computer program is run by a processor, each step of the far - sea wind farm fan control and protection coordination method as described in any one of the above is executed.

[0049] As can be seen from the above technical solutions, a method and related equipment for coordinating the control and protection of far - sea wind farm fans provided by the embodiments of the present application are applied to the sea - wind transmission and grid - connection system. The core lies in collecting the action information of the protection device in the far - sea wind farm transmission line in real time, accurately determining the wind farm fault information, and constructing a fault feature set including the real - time change characteristics of voltage and current; judging the severity of the fault based on this set, adopting a high - low ride - through control strategy to control the fan to ride through the fault for minor faults, and triggering the switch to trip and reasonably distributing the output of each fan in combination with the final output limit of the fan for severe faults; where the final output limit of the fan is determined by calculating the transmission channel capacity after the switch trips, the theoretical output limit of the wind farm, combining the safety margin coefficient to determine the safe operation limit, and then comprehensively obtaining the output limit under reactive power constraints based on the reactive power regulation ability of the on - shore station.

[0050] This solution can effectively overcome the defects of the prior art. On the one hand, by collecting the action information of the protection device in real time to construct a fault feature set, it realizes the fast and accurate judgment of faults, greatly shortens the fault recognition time, thus significantly improving the power regulation response speed and solving the problem of slow power regulation in the prior art. On the other hand, adopting a differentiated control strategy for different fault severities, the high - low ride - through control strategy during minor faults ensures that the fan can operate stably during the fault. The tripping and reasonable output distribution method during severe faults not only avoids system over - voltage, over - current and equipment overload, but also determines the final output limit of the fan through accurate calculation and comprehensive consideration of various factors, realizing the good coordination between protection actions and power regulation, and greatly shortening the time for the system to reach a steady state after the fault, providing a reliable and efficient means of energy control and protection coordination for the safe and stable operation of the far - sea wind farm. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0052] Figure 1 It is a flowchart of a method for coordinating the control and protection of far - sea wind farm fans disclosed in the embodiments of the present application;

[0053] Figure 2 It is a schematic structural diagram of a sea - wind transmission and grid - connection system disclosed in the embodiments of the present application;

[0054] Figure 3 It is a schematic diagram of a device for coordinating the control and protection of far - sea wind farm fans disclosed in the embodiments of the present application;

[0055] Figure 4 This is a hardware structure block diagram of a collaborative device for wind turbine control and protection in a far - sea wind farm disclosed in an embodiment of the present application. Detailed implementation manners

[0056] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0057] The present application can be used in many general - purpose or special - purpose computing device environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet - type devices, multi - processor devices, distributed computing environments including any of the above devices or equipment, and so on.

[0058] Next, the solution of the present application will be introduced. The present application proposes the following technical solutions. For details, please refer to the following text.

[0059] Figure 1 This is a flowchart of a collaborative method for wind turbine control and protection in a far - sea wind farm disclosed in an embodiment of the present application.

[0060] This method is applied to a sea - wind transmission and grid - connection system. As Figure 1 shown, the method may include:

[0061] Step S1: Determine the wind farm state and fault information according to the action information of the protection devices in the far - sea wind farm transmission line collected in real time, and establish a fault feature set including the real - time change characteristics of voltage and current.

[0062] Specifically, in a sea - wind transmission and grid - connection system, its typical structure is as Figure 2 shown, mainly composed of a sea - wind farm, an offshore station, an outgoing submarine cable, an onshore station, and a grid - connection point. The sea - wind farm is where wind turbines gather to generate electricity. The generated electricity is preliminarily processed by the offshore station. The offshore station is equipped with devices such as transformers to perform operations such as power conversion on the electric energy. Subsequently, the electricity is transmitted across the ocean to the onshore station through the outgoing submarine cable, which is a key transmission medium. The onshore station further adjusts the electric energy and other processes, and finally accesses the grid - connection point to achieve grid - connection with the large - scale power grid.

[0063] It is crucial to obtain the state and fault information of the far - sea wind farm in real time and accurately. The present application determines the wind farm state and fault information by collecting the action information of various protection devices configured in the far - sea wind farm transmission line in real time. These protection devices cover related equipment such as collector lines, transformers, and lines. The wind farm state and fault information are the basic data sources for constructing the fault feature set.

[0064] By collecting the action signals of protection devices in each link in real time, the current operating state of the wind farm is obtained. For example, the tripping signal of the protection device indicates that the system is in a fault state, and the alarm signal prompts the existence of potential abnormal operating conditions. The fault feature set is the result of in-depth data processing of the above-mentioned states and information. When the action of the protection device triggers the fault monitoring process, the system constructs a complete fault feature set based on the electrical quantity data such as voltage and current collected at the fault moment, by quantitatively calculating parameters such as voltage change, current change, voltage change rate, and current change rate. These parameters can accurately reflect the dynamic characteristics of electrical quantities at the moment of fault occurrence.

[0065] The fault feature set includes key parameters such as voltage change, current change, voltage change rate, and current change, which can reflect the real-time change characteristics of voltage and current, providing a comprehensive and accurate data basis for accurately evaluating the fault situation later.

[0066] The fault feature set can be:

[0067] Step S2: If it is determined that the current is a minor fault based on the fault feature set, a high-low ride-through control strategy is adopted to control the fan to ride through the fault.

[0068] Specifically, in the sea breeze transmission and grid connection system, when it is determined that the current fault is a minor fault based on the fault feature set established in step S1, for example, when the voltage change ΔU ≤ 0.2 p.u. and the duration is less than 100 ms, a high-low ride-through control strategy is adopted to control the fan to ride through the fault. The high-low ride-through control strategy aims to ensure that the fan can maintain stable operation during the fault. In the case of a minor fault, although the system voltage and current fluctuate, they are still within a relatively controllable range. Through this strategy, the fan can dynamically adjust its own operating parameters according to the real-time change information of voltage and current in the fault feature set, such as adjusting the fan pitch angle to change the wind energy capture amount, or adjusting the converter control strategy to maintain a stable power output, so as to achieve continuous operation of the fan during the fault, ensure the continuous supply of electricity, reduce the power generation loss caused by the fault, and improve the reliability and stability of the overall operation of the sea wind farm.

[0069] The low-voltage and high-voltage ride-through control strategy is a key means to ensure the stable operation of the wind turbine under abnormal grid voltage conditions, covering both low-voltage ride-through and high-voltage ride-through. During low-voltage ride-through, when the grid voltage drops, the wind turbine needs to maintain operation and inject a certain amount of reactive current into the grid to support the recovery of the grid voltage. For example, the direct-drive wind turbine adjusts the grid-side control to keep the machine-side power unchanged and reduce the grid-side absorbed power. At the same time, an energy-consuming device is added on the DC side to prevent overvoltage, and the active and reactive currents are calculated according to specific formulas based on national standards and other requirements. During high-voltage ride-through, in the face of the grid voltage rise, the wind turbine needs to limit the current to prevent equipment damage and also maintain a certain power output. For example, some wind turbines calculate the relevant current according to the rated power output. In the wind turbine output control method for this far-sea wind farm, when it is judged as a minor fault, the low-voltage and high-voltage ride-through control strategy is adopted. The wind turbine dynamically adjusts its own operating parameters, such as adjusting the pitch angle and the converter control strategy, according to the real-time change information of voltage and current in the fault feature set, to achieve uninterrupted operation and ensure power supply.

[0070] Step S3: If it is determined based on the fault feature set that the current is a serious fault, trigger the switch to trip, and allocate the output of each wind turbine according to the upper limit of the final output of the wind turbine to achieve the coordination of protection action and power regulation.

[0071] Among them, the determination process of the upper limit of the final output of the wind turbine includes:

[0072] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operation limit in combination with the safety margin coefficient;

[0073] Determine the output limit under reactive power constraints according to the reactive power regulation ability of the onshore substation, and comprehensively obtain the upper limit of the final output of the wind turbine based on the safe operation limit.

[0074] Specifically, in the sea wind transmission and grid-connection system, when it is determined based on the fault feature set that the current is a serious fault, for example, when the voltage change amount ΔU≥0.2 p.u. or the current change rate is greater than 0.3 p.u. or the duration is greater than 100 ms, step S3 needs to be executed. At this time, first trigger the switch to trip, which is to quickly isolate the fault, prevent the expansion of the fault range, and protect the system equipment from further damage.

[0075] After tripping, the output of each wind turbine needs to be allocated according to the upper limit of the final output of the wind turbine to achieve the coordination of protection action and power regulation. The determination process of the upper limit of the final output of the wind turbine is as follows:

[0076] Determine the safe operating limit: Calculate the transmission channel capacity after the switch trips and the theoretical output limit of the wind farm. The transmission channel capacity determines the maximum power that the system can safely transmit, and the theoretical output limit of the wind farm is the maximum output that the wind farm can reach under ideal conditions. Combine the safety margin coefficient, which is used to reserve a certain safety space to avoid risks caused by the system operating at the limit state, and comprehensively determine the safe operating limit to ensure the safe operation of the system after a fault.

[0077] Determine the output limit under reactive power constraints: Determine it according to the reactive power regulation ability of the onshore station. The reactive power regulation ability of the onshore station affects system performance such as voltage stability. The calculation formula for the output limit under reactive power constraints is:

[0078]

[0079] The calculation formula for the output limit under reactive power constraints comprehensively considers the limitations of active power output caused by factors such as grid voltage, system reactance, and the reactive power capacity of the onshore station.

[0080] Determine the upper limit of the final output of the fan: Take the smaller value between the safe operating limit and the output limit under reactive power constraints as the upper limit of the final output of the fan. This is because the system operation needs to meet both safety requirements and reactive power constraint conditions, and taking the smaller value can ensure the stable operation of the system under various limitations. After determining the upper limit of the final output of the fan, reasonably distribute the output of each fan accordingly, so that the entire wind farm can operate stably and safely after a fault, achieving the coordinated goal of protection action and power regulation.

[0081] The formula for determining the upper limit of the final output of the fan is:

[0082]

[0083] Among them, is the output limit under reactive power constraints, is the safe operating limit, is the grid connection point voltage, X is the system equivalent reactance, is the upper limit of the reactive power of the onshore station.

[0084] As can be seen from the above technical solution, a method and related equipment for coordinating the control and protection of far - sea wind farm fans provided by the embodiments of the present application are applied to the sea - wind transmission and grid - connection system. The core lies in collecting the action information of the protection device in the far - sea wind farm transmission line in real time, accurately determining the wind farm fault information, and constructing a fault feature set including the real - time change characteristics of voltage and current; judging the severity of the fault based on this set, adopting a high - low ride - through control strategy to control the fan to ride through the fault for minor faults, and triggering the switch to trip and reasonably distributing the output of each fan in combination with the ultimate output limit of the fan for severe faults; where the ultimate output limit of the fan is determined by calculating the transmission channel capacity after the switch trips, the theoretical output limit of the wind farm, combining with the safety margin coefficient to determine the safe operation limit, and then comprehensively obtaining the output limit under reactive power constraints based on the reactive power regulation ability of the on - shore station.

[0085] This solution can effectively overcome the defects of the existing technology. On the one hand, by collecting the action information of the protection device in real time to construct a fault feature set, it realizes the fast and accurate judgment of faults, greatly shortens the fault identification time, thus significantly improving the power regulation response speed and solving the problem of slow power regulation in the existing technology; on the other hand, adopting a differential control strategy for different fault severities, the high - low ride - through control strategy during minor faults ensures that the fan can operate stably during the fault, and the tripping and reasonable output distribution method during severe faults not only avoids system over - voltage, over - current and equipment overload, but also determines the ultimate output limit of the fan through precise calculation and comprehensive consideration of various factors, realizing good coordination between protection actions and power regulation, and greatly shortening the time for the system to reach a steady state after the fault, providing a reliable and efficient means of energy control and protection coordination for the safe and stable operation of the far - sea wind farm.

[0086] In some embodiments of the present application, the process of calculating the transmission channel capacity after the switch trips, the theoretical output limit of the wind farm, and combining with the safety margin coefficient to determine the safe operation limit is introduced, which can specifically include:

[0087] The first step: Calculate the transmission channel capacity according to the power limit of each transmission section after the switch trips;

[0088] The second step: Calculate the theoretical output limit of the wind farm based on the current meteorological conditions and fan parameters;

[0089] The third step: Determine the safe operation limit according to the transmission channel capacity, the theoretical output limit of the wind farm, and the safety margin coefficient.

[0090] Specifically, after the switch trips, the power transmission channel consists of multiple power transmission sections. Each power transmission section has its own power upper limit that it can withstand, which is the power limit. The capacity of the power transmission channel depends on the one with the smallest power limit among these power transmission sections. It's like a transportation channel composed of multiple sections of roads, and the transportation capacity is determined by the narrowest and worst-passing section of the road. We need to find the smallest value of the power limits among all the power transmission sections, and this minimum value is the capacity of the power transmission channel, which represents the maximum power that the current power transmission channel can safely transmit after the trip.

[0091] The theoretical output limit of the wind farm is related to the meteorological conditions and the parameters of the wind turbines. Meteorological factors such as wind speed and wind direction changes will affect the situation of the wind turbine blades capturing wind energy. And the specifications of the wind turbines themselves, such as the length of the blades and the rated power of the design and other parameters, determine the ability of the wind turbines to convert wind energy into electrical energy. Considering the current actual meteorological conditions and these parameters of the wind turbines themselves, the maximum amount of electricity that the wind farm can theoretically generate can be calculated, and this is the theoretical output limit of the wind farm.

[0092] After obtaining the capacity of the power transmission channel and the theoretical output limit of the wind farm, the safe operating limit should be the smaller of these two values, because the power during system operation cannot exceed the maximum power that the power transmission channel can transmit, nor can it exceed the maximum power that the wind farm can theoretically generate. After taking the smaller value, the safety margin coefficient also needs to be considered. The safety margin coefficient is to leave some margin for system operation to prevent problems from occurring when the system operates to the limit state due to possible aging of equipment, sudden weather changes and other unexpected situations. Subtract a part of the power calculated based on the safety margin coefficient and the capacity of the power transmission channel from the previously obtained smaller value, and the remaining is the safe operating limit, which can ensure the safe and stable operation of the system after a fault trip.

[0093] The calculation formula for the capacity of the power transmission channel is:

[0094]

[0095] The calculation formula for the safe operating limit is:

[0096]

[0097] Where, is the capacity of the power transmission channel, is the power limit of the i-th power transmission section, n is the number of power transmission sections, is the theoretical output limit of the wind farm, K is the safety margin coefficient, is the safe operating limit.

[0098] In some embodiments of the present application, the process of allocating the output of each wind turbine according to the final output upper limit of the wind turbine is introduced, which may specifically include:

[0099] Step 1: If the actual output of the current wind turbine does not exceed the upper limit of the final output of the wind turbine, the output of each wind turbine is allocated according to the principle of maximizing economic benefits;

[0100] Step 2: If the actual output of the current wind turbine exceeds the upper limit of the final output of the wind turbine, the reduction amount of the output is allocated according to the ratio of the rated power of each wind turbine, and the reduction amount of the output of a single wind turbine does not exceed a preset ratio of its rated power.

[0101] Specifically, when the actual output of the current wind turbine does not exceed the upper limit of the final output of the wind turbine, the output of each wind turbine is allocated according to the principle of maximizing economic benefits. The principle of maximizing economic benefits here comprehensively considers factors such as the revenue coefficient, cost coefficient related to the output of each wind turbine, and the cost coefficient related to the actual total output of the wind farm. The purpose is to adjust the output of each wind turbine to make the difference between the total revenue and the total cost reach the maximum under the conditions that the actual total output of the wind farm does not exceed the upper limit of the final output of the wind turbine, and the revenue and cost corresponding to the output of each wind turbine are reasonable (the calculation results of the relevant coefficients are non - negative).

[0102] The principle of maximizing economic benefits is as follows:

[0103]

[0104]

[0105] If the actual output of the current wind turbine exceeds the upper limit of the final output of the wind turbine, the reduction amount of the output needs to be allocated according to the ratio of the rated power of each wind turbine. When calculating specifically, first, based on the difference between the upper limit of the final output of the wind turbine and the actual output of the current wind turbine, combined with the ratio of the rated power of each wind turbine to the total rated power of all wind turbines, calculate the reduction amount of the output that should be allocated to each wind turbine. At the same time, to prevent the adjustment range of a single wind turbine from being too large, it is stipulated that the reduction amount of the output of a single wind turbine cannot exceed a preset ratio of its rated power. In this way, it can not only ensure that the total output of the wind farm meets the requirements of the upper limit of the final output, but also relatively fairly and reasonably let each wind turbine share the task of output adjustment and maintain the stable operation of the wind farm.

[0106] The calculation formula for the reduction amount of the output is:

[0107]

[0108]

[0109] Among them, is the revenue coefficient related to the output of the j - th wind turbine, is the cost coefficient related to the output of the j - th wind turbine, is the cost coefficient related to the actual total output of the wind farm, is the cost unrelated to the output of the wind farm, is the output of the j-th wind turbine, is the reduced output limit allocated to the j-th wind turbine, is the actual output of the current wind turbine, and m is the number of wind turbines, is the upper limit of the final output of the wind turbine, is the rated power of the j-th wind turbine.

[0110] Next, a wind turbine control and protection coordination device provided in an embodiment of the present application will be described. The wind turbine control and protection coordination device described below can be correspondingly referred to the wind turbine control and protection coordination method described above.

[0111] See Figure 3 , Figure 3 is a schematic diagram of a wind turbine control and protection coordination device disclosed in an embodiment of the present application.

[0112] As Figure 3 shown, the wind turbine control and protection coordination device may include:

[0113] A fault feature unit 110, configured to determine the wind farm state and fault information according to the action information of the protection device in the outgoing line of the far-sea wind farm collected in real time, and establish a fault feature set including the real-time change characteristics of voltage and current;

[0114] A first control unit 120, configured to control the wind turbine to cross the fault by using a high and low ride-through control strategy if it is determined that the current is a minor fault based on the fault feature set;

[0115] A second control unit 130, configured to trigger a switch trip if it is determined that the current is a severe fault based on the fault feature set, and allocate the output of each wind turbine according to the upper limit of the final output of the wind turbine, so as to achieve the coordination of protection action and power regulation;

[0116] The determination process of the upper limit of the final output of the wind turbine includes:

[0117] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trip, and determine the safe operation limit value in combination with the safety margin coefficient;

[0118] Determine the output limit under reactive power constraints according to the reactive power regulation ability of the onshore substation, and comprehensively obtain the upper limit of the final output of the wind turbine based on the safe operation limit value.

[0119] As can be seen from the above technical solutions, a coordinated method for wind turbine control and protection and related equipment provided by the embodiments of the present application are applied to the sea wind transmission and grid connection system. The core lies in accurately determining the wind farm fault information by collecting the action information of the protection device in the transmission line of the far sea wind farm in real time, and constructing a fault feature set including the real-time change characteristics of voltage and current; judging the severity of the fault based on this set, adopting a high and low ride-through control strategy to control the wind turbine to ride through the fault for minor faults, and triggering switch tripping and reasonably distributing the output of each wind turbine in combination with the final output limit of the wind turbine for severe faults; among which the final output limit of the wind turbine is determined by calculating the transmission channel capacity after switch tripping, the theoretical output limit of the wind farm, combining with the safety margin coefficient to determine the safe operation limit, and then comprehensively obtaining the output limit under reactive power constraints based on the reactive power regulation ability of the onshore substation.

[0120] This solution can effectively overcome the defects of the prior art. On the one hand, by collecting the action information of the protection device in real time to construct a fault feature set, it realizes the rapid and accurate judgment of faults, greatly shortens the fault identification time, thus significantly improving the power regulation response speed and solving the problem of slow power regulation in the prior art; on the other hand, adopting a differential control strategy for different fault severities, the high and low ride-through control strategy during minor faults ensures that the wind turbine can continue to operate stably during the fault, and the tripping and reasonable output distribution method during severe faults not only avoids system overvoltage, overcurrent and equipment overload, but also determines the final output limit of the wind turbine by accurately calculating and comprehensively considering various factors, realizing the good coordination between protection actions and power regulation, greatly shortening the time for the system to reach a steady state after the fault, and providing a reliable and efficient energy control and protection coordination means for the safe and stable operation of the far sea wind farm.

[0121] Optionally, calculating the transmission channel capacity after switch tripping and the theoretical output limit of the wind farm, and determining the safe operation limit in combination with the safety margin coefficient includes:

[0122] Calculating the transmission channel capacity according to the power limit of each transmission section after switch tripping;

[0123] Calculating the theoretical output limit of the wind farm based on the current meteorological conditions and wind turbine parameters;

[0124] Determining the safe operation limit according to the transmission channel capacity, the theoretical output limit of the wind farm and the safety margin coefficient.

[0125] Optionally, the calculation formula for the transmission channel capacity is:

[0126]

[0127] The calculation formula for the safe operation limit is:

[0128]

[0129] Among them, is the transmission channel capacity, is the power limit of the i-th transmission section, and n is the number of transmission sections. is the theoretical output limit of the wind farm, and K is the safety margin coefficient. is the safe operation limit value.

[0130] Optionally, the output allocation of each wind turbine according to the upper limit of the final output of the wind turbine includes:

[0131] If the actual output of the current wind turbine does not exceed the upper limit of the final output of the wind turbine, the output of each wind turbine is allocated according to the principle of maximizing economic benefits;

[0132] If the actual output of the current wind turbine exceeds the upper limit of the final output of the wind turbine, the reduction amount of the output is allocated according to the ratio of the rated power of each wind turbine, and the reduction amount of the output of a single wind turbine does not exceed a preset ratio of its rated power.

[0133] Optionally, the principle of maximizing economic benefits is:

[0134]

[0135]

[0136] The calculation formula for the reduction amount of the output is:

[0137]

[0138]

[0139] Among them, is the revenue coefficient related to the output of the j-th wind turbine, is the cost coefficient related to the output of the j-th wind turbine, is the cost coefficient related to the actual total output of the wind farm, is the cost unrelated to the output of the wind farm, is the output of the j-th wind turbine, is the reduction amount of the output allocated to the j-th wind turbine, is the actual output of the current wind turbine, m is the number of wind turbines, is the upper limit of the final output of the wind turbine, is the rated power of the j-th wind turbine.

[0140] Optionally, the calculation formula for the output limit value under reactive power constraint is:

[0141]

[0142] The formula for determining the upper limit of the final output of the fan is as follows:

[0143]

[0144] Wherein, is the output limit under reactive power constraint, is the safe operation limit, is the grid connection point voltage, X is the equivalent reactance of the system, is the upper limit of reactive power of the onshore substation.

[0145] The far-sea wind farm fan control and protection coordination device provided by the embodiments of the present application can be applied to far-sea wind farm fan control and protection coordination equipment. Figure 4 shows the hardware structure block diagram of the far-sea wind farm fan control and protection coordination equipment. Referring to Figure 4 , the hardware structure of the far-sea wind farm fan control and protection coordination equipment may include: at least one processor 1, at least one communication interface 2, at least one memory 3, and at least one communication bus 4;

[0146] 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;

[0147] 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.;

[0148] 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;

[0149] Wherein, the memory stores a program, and the processor can call the program stored in the memory. The program is used for:

[0150] Determine the wind farm state and fault information according to the action information of the protection device in the far-sea wind farm transmission line collected in real time, and establish a fault feature set including the real-time change characteristics of voltage and current;

[0151] If it is determined that the current is a minor fault based on the fault feature set, a high-low ride-through control strategy is adopted to control the fan to ride through the fault;

[0152] If it is determined that the current is a serious fault based on the fault feature set, the switch is tripped, and the output of each fan is allocated according to the upper limit of the final output of the fan to achieve the coordination of protection action and power regulation;

[0153] The process of determining the upper limit of the final output of the fan includes:

[0154] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operating limit in combination with the safety margin coefficient;

[0155] Determine the output limit under reactive power constraints according to the reactive power regulation ability of the onshore substation, and obtain the upper limit of the final output of the fan by synthesizing the safe operating limit.

[0156] Optionally, the refinement function and expansion function of the program can be referred to the above description.

[0157] The embodiment of the present application also provides a readable storage medium, which can store a program suitable for execution by a processor, and the program is used for:

[0158] Determine the wind farm state and fault information according to the action information of the protection device in the transmission line of the far-sea wind farm collected in real time, and establish a fault feature set including the real-time change characteristics of voltage and current;

[0159] If it is determined that the current is a minor fault based on the fault feature set, the high-low ride-through control strategy is used to control the fan to ride through the fault;

[0160] If it is determined that the current is a serious fault based on the fault feature set, trigger the switch to trip, and allocate the output of each fan according to the upper limit of the final output of the fan to achieve the coordination of protection action and power regulation;

[0161] The process of determining the upper limit of the final output of the fan includes:

[0162] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operating limit in combination with the safety margin coefficient;

[0163] Determine the output limit under reactive power constraints according to the reactive power regulation ability of the onshore substation, and obtain the upper limit of the final output of the fan by synthesizing the safe operating limit.

[0164] Optionally, the refinement function and expansion function of the program can be referred to the above description.

[0165] The embodiment of the present application also provides a computer program product, including a computer program, and the method executed when the computer program is run by a processor is:

[0166] Determine the wind farm state and fault information according to the action information of the protection device in the transmission line of the far-sea wind farm collected in real time, and establish a fault feature set including the real-time change characteristics of voltage and current;

[0167] If it is determined that the current is a minor fault based on the set of fault characteristics, a high-low ride-through control strategy is adopted to control the wind turbine to ride through the fault;

[0168] If it is determined that the current is a severe fault based on the set of fault characteristics, the switch is tripped, and the output of each wind turbine is allocated according to the upper limit of the final output of the wind turbine to achieve the coordination of protection actions and power regulation;

[0169] The determination process of the upper limit of the final output of the wind turbine includes:

[0170] Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operation limit in combination with the safety margin coefficient;

[0171] According to the reactive power regulation ability of the onshore substation, determine the output limit under reactive power constraints, and comprehensively obtain the upper limit of the final output of the wind turbine based on the safe operation limit.

[0172] Optionally, the refinement function and expansion function of the program can be referred to the above description.

[0173] Finally, it should also be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent in such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0174] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0175] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coordinated method for wind turbine control and protection in far - sea wind farms, characterized in that, Applied to the sea breeze sending and grid-connected system, the method includes: Determine the wind farm status and fault information based on the action information of the protection device in the far sea wind farm sending line collected in real time, and establish a fault feature set including the real-time change characteristics of voltage and current; If it is determined that the current is a minor fault based on the fault feature set, adopt the high and low ride-through control strategy to control the fan to ride through the fault; If it is determined that the current is a serious fault based on the fault feature set, trigger the switch to trip, and allocate the output of each fan according to the ultimate output limit of the fan to achieve the coordination of protection action and power regulation; The determination process of the ultimate output limit of the fan includes: Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operation limit in combination with the safety margin coefficient; Determine the output limit under reactive power constraints according to the reactive power regulation ability of the onshore station, and comprehensively obtain the ultimate output limit of the fan based on the safe operation limit.

2. The method according to claim 1, wherein Calculating the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determining the safe operation limit in combination with the safety margin coefficient includes: Calculate the transmission channel capacity according to the power limit of each transmission section after the switch trips; Based on the current meteorological conditions and fan parameters, calculate the theoretical output limit of the wind farm; Determine the safe operation limit according to the transmission channel capacity, the theoretical output limit of the wind farm, and the safety margin coefficient.

3. The method according to claim 2, wherein The calculation formula of the transmission channel capacity is: The calculation formula of the safe operation limit is: Among them, is the transmission channel capacity, is the power limit of the i-th transmission section, n is the number of transmission sections, is the theoretical output limit of the wind farm, K is the safety margin coefficient, is the safe operation limit value.

4. The method according to claim 1, wherein The allocation of the output of each fan according to the ultimate output limit of the fan includes: If the actual output of the current fan does not exceed the ultimate output limit of the fan, allocate the output of each fan according to the principle of maximizing economic benefits; If the actual output of the current fan exceeds the ultimate output limit of the fan, allocate the reduction amount of the output according to the ratio of the rated power of each fan, and the reduction amount of the output of a single fan does not exceed a preset ratio of its rated power.

5. The method according to claim 4, characterized in that The principle of maximizing economic benefits is: The calculation formula of the reduction amount of the output is: Among them, is the revenue coefficient related to the output of the j-th wind turbine, is the cost coefficient related to the output of the j-th wind turbine, is the cost coefficient related to the actual total output of the wind farm, is the cost independent of the output of the wind farm, is the output of the j-th wind turbine, is the reduced output amount allocated to the j-th wind turbine, is the actual output of the current wind turbine, m is the number of wind turbines, is the upper limit of the final output of the wind turbine, is the rated power of the j-th wind turbine.

6. The method according to claim 1, wherein The calculation formula of the output limit under reactive power constraints is: The determination formula of the ultimate output limit of the fan is: Among them, is the output limit under reactive power constraints, is the safe operation limit, is the grid connection point voltage, X is the equivalent reactance of the system, is the upper limit of reactive power of the onshore substation.

7. A coordinated device for wind turbine control and protection in a far - sea wind farm, characterized in that, Including: A fault feature unit for determining the wind farm status and fault information based on the action information of the protection device in the far sea wind farm sending line collected in real time, and establishing a fault feature set including the real-time change characteristics of voltage and current; A first control unit for, if it is determined that the current is a minor fault based on the fault feature set, adopting the high and low ride-through control strategy to control the fan to ride through the fault; A second control unit for, if it is determined that the current is a serious fault based on the fault feature set, triggering the switch to trip, and allocating the output of each fan according to the ultimate output limit of the fan to achieve the coordination of protection action and power regulation; The determination process of the ultimate output limit of the fan includes: Calculate the transmission channel capacity and the theoretical output limit of the wind farm after the switch trips, and determine the safe operation limit in combination with the safety margin coefficient; Determine the output limit under reactive power constraints according to the reactive power regulation ability of the onshore station, and comprehensively obtain the ultimate output limit of the fan based on the safe operation limit.

8. A collaborative device for wind turbine control and protection in a far - sea wind farm, characterized in that, Including a memory and a processor; The memory is used to store programs; The processor is used to execute the program to implement each step of the method for coordinating the control and protection of the far - sea wind farm turbines as described in any one of claims 1 - 6.

9. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements each step of the method for coordinating the control and protection of the far - sea wind farm turbines as described in any one of claims 1 - 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program runs on the processor, it executes each step of the method for coordinating the control and protection of the far - sea wind farm turbines as described in any one of claims 1 - 6.

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