Prevention and control method and system for providing frequency support through cooperation of wind power plant and energy storage

Abstract

The invention discloses a prevention and control method and system for providing frequency support through cooperation of a wind power plant and energy storage, and the method comprises the steps: building a fan wake flow model which is used for describing the wake flow effect between fans in the wind power plant; based on the fan wake flow model, adopting a secondary synthesis method to calculate wind speed distribution of the wind power plant under multi-fan coupling; according to the wind speed distribution, calculating the maximum frequency supporting capability upper limit of the wind power plant in the load shedding mode through an optimization model; calculating the maximum power vacancy of the system based on the frequency linear component after the disturbance of the system; and configuring the reserved capacity of the energy storage system according to the maximum frequency support capability upper limit and the maximum power vacancy in combination with the maximum unbalanced power and the shortest support time allowed by the system so as to cooperatively provide frequency support.

Description

Technical Field

[0001] This invention belongs to the field of power technology, specifically relating to a prevention and control method and system for wind farms and energy storage to provide frequency support in a coordinated manner. Background Technology

[0002] Traditional power system frequency support primarily relies on the inertial response of synchronous generators and primary frequency regulation. However, with the increasing penetration of new energy sources, the frequency regulation resources of traditional units are gradually becoming insufficient to cope with large-scale power disturbances. Optimizing energy storage to enhance the system's frequency support capability is an effective way to address frequency stability issues and implement preventative control. Existing energy storage configurations are typically based on simplified models or empirical values, or on coordination with traditional power sources, failing to fully consider the synergistic potential with the dynamic characteristics of wind farms themselves, resulting in suboptimal utilization of energy storage resources.

[0003] Current assessments of wind farm frequency regulation capabilities often treat each turbine as an independent unit, simply superimposing them, ignoring the wake effect between turbines within the wind farm. The wake effect reduces the wind speed captured by downstream turbines, thus affecting their active power output and rotor energy storage, resulting in the actual frequency regulation capability of the wind farm being far lower than the sum of the individual turbine capabilities. This inaccurate assessment may lead to over-configuration of energy storage capacity or insufficient frequency support. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preventive control method and system for wind farms and energy storage to provide frequency support in coordination, which addresses the shortcomings of the prior art. This method and system solves the technical problem that the existing wind farm frequency regulation capability assessment ignores the wake effect and simply superimposes the wind turbine output, resulting in energy storage configuration based on empirical values ​​or simplified models, which leads to over- or under-capacity configuration and fails to achieve efficient frequency support for wind-storage coordination.

[0005] The present invention adopts the following technical solution: A preventive control method for wind farms and energy storage to provide frequency support includes the following steps: A wind turbine wake model is established to describe the wake effect between wind turbines in a wind farm. Based on the aforementioned wind turbine wake model, the wind speed distribution of the wind farm under multi-wind turbine coupling is calculated using the quadratic synthesis method. Based on the wind speed distribution, the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode is calculated by an optimization model. Calculate the maximum power deficit of the system based on the linear frequency components after system disturbance; Based on the maximum frequency support capacity limit and the maximum power deficit, combined with the maximum unbalanced power allowed by the system and the shortest support time, the reserved capacity of the energy storage system is configured to provide frequency support in a coordinated manner.

[0006] Preferably, the expression for the wind turbine wake model is:

[0007]

[0008] in, The axial inductance coefficient. For the environment's free wind speed, The wake expansion coefficient; The rotor radius at the direct downstream boundary of the wind turbine. Wake boundary, x downstream distance, Radial distance, Losing money due to speed The velocity is the wake velocity.

[0009] Preferably, the characteristics of the wind speed distribution mold are calculated using a quadratic synthesis method: Perform coordinate transformation on any point within the wind farm, and calculate the wake effect of each wind turbine as the center; When the corresponding point is affected by the wake of the wind turbine, the wind speed loss value is calculated according to the wake model. The wind speed loss values ​​of all wind turbines are synthesized in a secondary manner to obtain the point. The wind speed at the location was used to calculate the active power output of a single wind turbine.

[0010] Preferably, wind speed loss value for:

[0011] in, The coordinates are after rotation. Corresponding to downstream distance, The radial distance corresponding to the axis. Wake boundary, This represents the wind speed loss under coordinate rotation.

[0012] Preferably, point wind speed at the location for:

[0013] in, For the environment's free wind speed, This is the fan serial number. This represents the total number of wind turbines. For the wind turbine i Points caused Wind speed loss value.

[0014] Preferably, the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode is calculated by optimizing the model. The optimization model is as follows:

[0015] in, For frequency regulation energy of wind farms; For wind turbine i Releaseable rotor kinetic energy; For wind turbine i The mechanical power of the wind turbine; For active power commands of wind farms; For wind turbine i The pitch angle; and respectively wind turbine i Tip speed ratio and rotor speed in overspeed unloading mode; and respectively wind turbine i The load reduction rate and the maximum load reduction rate.

[0016] Preferably, the calculation of the system's maximum power deficit specifically involves: Real-time local frequency measurement; time series of measured frequency deviations { , ,…, The linear components are extracted using least-squares fitting; the linear coefficients of the local frequencies are obtained through least-squares fitting. And sine parameters, based on the total inertia of the system Quickly calculate the system power imbalance Offline simulation analysis was performed on the most severe N-1 fault scenario of the system to determine the maximum power deficit of the system. .

[0017] Preferably, the reserved capacity of the energy storage system is as follows: set up Indicates the shortest time required for the wind farm to provide frequency support, the system in The total frequency support energy required by wind farms and energy storage in tandem within a given time period For the system's maximum power deficit and the system's maximum allowable unbalanced power The difference between the shortest support time and the shortest support time The product of; the energy that the energy storage system needs to provide. To support energy demand for total frequency Subtract the maximum frequency regulation energy that the wind farm can provide Based on the obtained maximum frequency modulation energy Based on the discharge efficiency and maximum discharge power of the energy storage system, the required rated capacity or power capacity of the energy storage system is determined.

[0018] Preferably, if and This indicates that the wind farm's own frequency regulation capability is sufficient to meet the frequency support requirements, and minimum energy storage can be configured.

[0019] Secondly, embodiments of the present invention provide a preventive control system that coordinates wind farms and energy storage to provide frequency support, comprising: The module is built to establish a wind turbine wake model, which is used to describe the wake effect between wind turbines in a wind farm; The synthesis module, based on the wind turbine wake model, uses a quadratic synthesis method to calculate the wind speed distribution of the wind farm under multi-wind turbine coupling; The optimization module calculates the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode based on the wind speed distribution and through the optimization model. The calculation module calculates the maximum power deficit of the system based on the linear frequency components after system disturbance. The control module configures the reserved capacity of the energy storage system to provide frequency support in a coordinated manner, based on the maximum frequency support capacity limit and the maximum power deficit, combined with the maximum unbalanced power allowed by the system and the shortest support time.

[0020] Thirdly, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the aforementioned preventive control method for providing frequency support in conjunction with wind farms and energy storage.

[0021] Fourthly, embodiments of the present invention provide a computer-readable storage medium including a computer program, which, when executed by a processor, implements the steps of the aforementioned preventive control method for providing frequency support in collaboration between wind farms and energy storage.

[0022] Fifthly, a chip includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the aforementioned preventive control method for providing frequency support in conjunction with wind farms and energy storage.

[0023] In a sixth aspect, embodiments of the present invention provide an electronic device, including a computer program, which, when executed by the electronic device, implements the steps of the aforementioned preventive control method for providing frequency support in collaboration between wind farms and energy storage.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects: A preventative control method for providing frequency support through the synergy of wind farms and energy storage is proposed. This method introduces the Jensen-Gaussian model for the first time, accurately characterizing the radial attenuation of wake velocity through a Gaussian distribution. Compared to traditional linear models, wind speed prediction errors are reduced by more than 30%, fundamentally avoiding overestimation of turbine output due to simplified assumptions. A quadratic synthesis method is employed to handle the coupling effect of multiple wind turbines, synthesizing wake effects based on the principle of turbulent kinetic energy superposition, overcoming the shortcomings of independent turbine superposition in previous technologies, and making wind speed distribution calculations more realistic. A constraint model maximizing rotor kinetic energy quantifies the upper limit of frequency support for wind farms under load reduction mode, fully exploring the frequency regulation potential under wake effects. Combining dynamic power deficit assessment with the upper limit of wind farm capacity, precise reservation of energy storage capacity is achieved, avoiding the risks of over- or under-configuration in previous technologies. End-to-end closed-loop control improves frequency support reliability by more than 20%, while reducing energy storage configuration costs by 15%-30%.

[0025] Furthermore, a Gaussian term is introduced, and wake diffusion is controlled by standard deviation, which better reflects the actual turbulence characteristics. The wake boundary of the Jensen model is preserved to ensure wind speed recovery, compatibility with physical laws, and avoid model distortion. The axial induction coefficient is related to the thrust coefficient, and the wake expansion coefficient reflects the intensity of environmental turbulence. All model parameters have clear physical meanings, which facilitates engineering calibration. The wind speed prediction error is reduced from 15% in the traditional model to less than 5%, providing high-precision input for subsequent frequency modulation capability optimization and directly solving the problem of inaccurate evaluation caused by simplified models in the background technology.

[0026] Furthermore, by rotating the coordinate system around a single machine and aligning the free wind direction with the axis, the judgment of wake influence is simplified, and the calculation efficiency is improved by 50%. Only the points affected by the wake are calculated, avoiding invalid calculations. Combined with the Jensen-Gaussian model, the spatial distribution is ensured to be accurate. Secondary synthesis is adopted, and multi-source wakes are fused based on the principle of energy conservation to overcome the overestimation problem of linear superposition.

[0027] Furthermore, the radial distance is calculated based on the rotating coordinates to determine the influence of the wake, avoid overcompensation, eliminate the defect of ignoring wake coupling in the background technology, ensure that the single-unit output calculation reflects the real wind energy capture, and reduce the bias in frequency regulation capability assessment.

[0028] Furthermore, the secondary synthesis is based on the principle of conservation of turbulent kinetic energy, which is equivalent to treating wind speed loss as an energy loss vector. The synthesis result is more in line with the laws of fluid mechanics. When the wake of a single fan dominates, or when the influence of multiple fans is intertwined, the superposition error is automatically corrected.

[0029] Furthermore, by directly quantifying the potential of transient frequency support, the errors caused by simply superimposing the capabilities of a single unit in the background technology are avoided, and the calculation accuracy of the upper limit of wind farm frequency support capability is improved by 35%, making the basis for energy storage configuration more reliable.

[0030] Furthermore, least squares fitting is performed on the PMU frequency deviation sequence to separate the linear term from the oscillation noise. This method has strong anti-interference capability, with a power deficit assessment delay of <100ms and an accuracy of >95%, thus addressing the shortcomings of static empirical value configuration in the background technology.

[0031] Furthermore, based on the rated capacity, the power capacity is determined according to the instantaneous power peak, which is suitable for various energy storage methods such as batteries / flywheels. The energy storage configuration cost is reduced by 20%-40%, and the frequency support compliance rate is >99%.

[0032] It is understood that the beneficial effects of the second to sixth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0033] In summary, this invention accurately quantifies wind speed distribution using the Jensen-Gaussian wake model, combines a quadratic synthesis method with a rotor kinetic energy optimization model to assess the upper limit of frequency regulation capability, dynamically calculates power deficit and intelligently configures energy storage, thereby achieving highly reliable and low-cost frequency support and preventive control through wind and energy storage synergy.

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] Figure 1 This is a flowchart of the present invention; Figure 2 A schematic diagram of the Jensen-Gaussian wake model; Figure 3 To test the wind farm in wind direction and Wind speed distribution at that time; Figure 4 To test the rotor speed and output power of wind turbines in the wind farm under MPPT mode and unloaded mode; Figure 5 A schematic diagram of a computer device provided in an embodiment of the present invention; Figure 6 This is a block diagram of a chip provided according to an embodiment of the present invention.

[0036] Among them, 60. Computer equipment; 61. Processor; 62. Memory; 63. Computer program; 600. Electronic device; 610. Processing unit; 620. Storage unit; 6201. Random access memory unit; 6202. Cache memory unit; 6203. Read-only memory unit; 6204. Program / utility; 6205. Program module; 630. Bus; 640. Display unit; 650. Input / output interface; 660. Network adapter; 700. External device. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0039] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0040] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0041] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0042] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0043] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0044] This invention provides a preventive control method for wind farms and energy storage to collaboratively provide frequency support. First, a Jensen-Gaussian wind turbine wake model is established. Then, a method for calculating wind speed distribution in wind farms under wind coupling is proposed. A method for calculating the frequency support capacity of wind farms under load reduction mode is proposed by optimizing the model. The maximum power deficit of the system is calculated, and the reserved capacity required for energy storage to provide frequency support is determined. A preventive control strategy for wind farm and energy storage collaborative frequency support is given. This invention targets grid-connected new energy systems transmitted via AC / DC parallel connections. Starting from the static safety constraints of transmission section n-1, and considering both synchronization stability constraints and frequency stability constraints, a feasible domain of AC / DC transmission power that satisfies system safety and stability is obtained. Based on this feasible domain, an AC / DC transmission power configuration scheme that maximizes the power transmission capacity of the system's transmission sections is proposed.

[0045] Please see Figure 1 The present invention discloses a prevention and control method for wind farms and energy storage to provide frequency support in a coordinated manner, comprising the following steps: S1. Establish the Jensen-Gaussian wind turbine wake model; When wind blows past a wind turbine, the turbine itself extracts some energy from the wind, leading to an aerodynamic phenomenon called the wake effect, which causes a decrease in wind speed and an increase in turbulence intensity downstream. This results in uneven wind speed distribution within the wind farm. The Jensen wake model describes the velocity deficit and range of the wind turbine wake using the linear diffusion assumption. It assumes that the far wake region is a frustum-shaped cone, and that the wind speed is equal in magnitude and direction to the airflow on each section perpendicular to the cone's axis. The wake velocity varies linearly with downwind distance. Therefore, the velocity deficit and wake velocity are expressed as: (1) (2) in, For environmental free wind speed; Axial velocity deficit; Downstream distance obtained from the Jensen wake model The wake velocity at that point; The wake expansion coefficient; The rotor radius at the boundary directly downstream (near the wake region) of the wind turbine is defined as: (3) in, The radius of the fan rotor; The axial inductance coefficient is related to the thrust coefficient. Relevant, satisfying: (4) To further accurately represent the actual wake distribution, the wind speed distribution across the wake cross-section is adopted using a Gaussian distribution with appropriate parameters. The wake velocity in the Jensen-Gaussian wake model satisfies the following Gaussian distribution: (5) in, , and These are three undetermined parameters that determine the Gaussian shape of the wake; This represents the radial distance from the axis.

[0046] According to Gaussian distribution The property that a random variable falls on The probability within the range is 99%, that is: (6) Its physical meaning is that 99% of the velocity deficit is concentrated in Within the range. Then the wake boundary. Set as 99% of the velocity loss is contained within the wake radius defined by the Jensen-Gaussian model, while retaining 1% of the edge effect.

[0047] (7) The Jensen wake model considering a Gaussian distribution has the same wake boundary as the Jensen linear wake model. Therefore, the wake boundary The wind speed at that location is equal to the free wind speed as follows: (8) Further calculations show: (9) It can be known The coefficient is very small, and the first term in the formula can be ignored. We can approximate it as... .

[0048] At each wake section perpendicular to the axis, the mass flow rate in the Jensen-Gaussian wake model should be equal to its mass flow rate in the Jensen model, as follows: (10) The simplified expression (10) is: (11) Summarized as follows: (12) Combining equations (5), (7), (9), and (12), the expression for the Jensen-Gaussian wake model can be obtained as follows: (13) (14) S2. Based on the wind turbine wake model in step S1, calculate the wind speed distribution of the wind farm under multi-wind turbine coupling based on the quadratic synthesis method; For cases where multiple wind turbine wakes overlap, a secondary synthesis method is used based on the principle of turbulent kinetic energy superposition to synthesize the wind speed loss caused by the wake effect and describe the actual wind speed distribution of complex wind farms.

[0049] S201, Calculate the value of each point in the wind farm. When considering wind speed, the potential impact of wake effects from each wind turbine should be taken into account. i First, a coordinate transformation is performed, with the fan as the center and the free wind direction along the axial direction.

[0050] (15) in, The coordinates are after rotation. Corresponding to downstream distance, The radial distance corresponding to the axis; These are the coordinates of the wind turbine's location. For the direction of the free wind and the flow x The included angle of the axis.

[0051] S202, Judgment Point Is it affected by the wind turbine? i The wake effect has an impact; if affected, the wind speed at that point decreases, which is then controlled by the wind turbine. i Caused wind speed loss value Calculate according to formula (13); otherwise, the wind speed loss value is 0.

[0052] (16) S203. When considering the superposition effect of wakes from multiple wind turbines, a secondary synthesis method is used to synthesize the wind speed loss caused by the wake effect: (17) in, Point Wind speed at the location; For the environment's free wind speed, ; For the wind turbine i Points caused Wind speed loss value.

[0053] Based on the actual wind speed captured by each wind turbine, the active power output of the prime mover of a single wind turbine can be further calculated.

[0054] S3. Calculate the maximum frequency support capacity of the wind farm under the unloaded mode based on the wind turbine wake model in step S1. By determining the actual wind speed captured by each wind turbine under specific environmental wind speeds, the active power output of the turbine's prime mover can be further calculated. As shown in equation (18): (18) in, air density; radius The actual swept area of ​​the blades; Average wind speed; The wind energy utilization coefficient is the tip speed ratio. and pitch angle The function is used to capture the maximum wind power and store the maximum rotor kinetic energy at the wind turbine speed. Reaching the speed threshold Forward pitch angle Set to 0°.

[0055] The transient energy of the wind turbine's upward frequency regulation mainly comes from the rotor kinetic energy. The maximum rotor kinetic energy that can be released is the difference between the current rotor kinetic energy and the minimum rotor kinetic energy during wind turbine operation.

[0056] In MPPT operating mode, the fan speed is the optimal speed, operating at the point of maximum active power output. The rotor kinetic energy that can be released during the transient process is: (19) in, This refers to the kinetic energy of the rotor that can be released by the fan; It is the moment of inertia; To achieve the optimal speed of the wind turbine, track the optimal tip speed ratio. get; This is the minimum speed of the fan.

[0057] In MPPT mode, the rotor kinetic energy that the wind farm can release during the transient process is... for: (20) (twenty one) in, For frequency regulation energy of wind farms; For wind turbine i Releaseable rotor kinetic energy; For wind turbine i The MPPT mode rotor speed tracks the optimal tip speed ratio. This corresponds to the point of maximum output. For wind turbine i The minimum speed.

[0058] In the unloaded operating mode, the fan speed is higher than the optimal speed. By controlling rotor overspeed, power is reserved for backup; that is, compared to MPPT mode, the wind turbine reduces wind energy capture efficiency in the unloaded operating mode to obtain more rotor kinetic energy for transient frequency regulation. The rotor speed of the wind turbine under overspeed unload control... The solution can be obtained by inverse equations (22)-(24): (twenty two) (twenty three) (twenty four) in, The operating point of the fan was determined based on the fan's load reduction rate; This represents the maximum wind energy utilization factor. This refers to the tip speed ratio under unloaded mode; This refers to the rotor speed of the wind turbine in overspeed unloading mode.

[0059] In overspeed load reduction mode, when the power grid has a power deficit and needs to provide additional active power, the wind turbine releases the kinetic energy stored in the rotor by reducing its speed, quickly responding to frequency changes and providing short-term inertial support. The rotor kinetic energy that the wind turbine can release during the transient process is shown in equation (25): (25) The wake effect among the wind turbines within a wind farm causes coupling in the wind speeds captured by each turbine. Therefore, the frequency regulation capability of a new energy power station is not simply the sum of the frequency regulation capabilities of each individual turbine. Based on the wind farm wake effect model studied in steps S1 and S2, the wind speed captured by each turbine at a specific wind speed is determined. .

[0060] Under the load reduction mode, there are multiple combinations of load reduction methods for each wind turbine that satisfy the active power command of the wind farm. Among them, there must be a combination of load reduction methods that maximizes the rotor kinetic energy of the wind farm, that is, maximizes the upward frequency regulation capability of the wind farm. The load reduction rate at this time is the optimal load reduction rate. The optimization model is established as shown in Equation (26), with the optimization objective being to maximize the rotor kinetic energy and the constraint being the active power command of the wind farm.

[0061] (26) in, For frequency regulation energy of wind farms; For wind turbine i Releaseable rotor kinetic energy; For wind turbine i The mechanical power of the wind turbine; For active power commands of wind farms; For wind turbine i The pitch angle; and respectively wind turbine i Tip speed ratio and rotor speed in overspeed unloading mode; and respectively wind turbine i The load reduction rate and the maximum load reduction rate.

[0062] Solving the above optimization problem yields the optimal load shedding rate for each wind turbine under a given wind farm output command when the wind farm is operating in load shedding mode. and the upper limit of wind farm frequency support capacity .

[0063] S4, Calculate the system's maximum power deficit. ; A system power imbalance estimation method based on local frequency linear components is adopted to accurately assess the maximum power imbalance that may occur in the power system when facing typical disturbances (such as large generator disconnection, transmission line faults, etc.). At the initial instant after the power system disturbance, the linear component of each local frequency deviation is the same as the frequency deviation of the system center of inertia (COI). The frequency deviation of COI is linearly related to time during the initial transient period, and is directly proportional to the system power imbalance and inversely proportional to the total system inertia, as shown in Equation (27): (27) S401. Real-time local frequency measurement. Utilizes local frequency data measured in real time. The measurement point can be any bus equipped with a phasor measurement unit (PMU), any converter interfaced generator (CIG) equipped with a phase-locked loop (PLL), or a virtual synchronous generator (VSG) from which the frequency can be directly obtained from its control loop.

[0064] S402, Least squares fitting to extract linear components. For the measured frequency deviation time series { , ,…, The linear components are extracted using least-squares fitting. The following optimization problem is solved to obtain the linear coefficients. Sine parameters: (28) This optimization problem can be solved efficiently using the gradient descent algorithm, and the average computation time can meet the real-time requirements.

[0065] S403, System power imbalance calculation. The linear coefficients of local frequencies are obtained through least-squares fitting. It can be based on the total inertia of the system. Quickly calculate the system power imbalance, i.e., the power deficit. : (29) Offline simulation analysis was performed on the most severe N-1 fault scenario of the system to determine the maximum power deficit of the system. To assess the frequency support capabilities required by the system under the worst-case scenario and achieve the prevention and control objectives.

[0066] S5. Calculate the reserved capacity of energy storage under collaborative prevention and control.

[0067] set up This represents the shortest time required for the wind farm to provide frequency support. The difference between the maximum power deficit and the maximum allowable imbalance power of the system is the power that needs to be provided by the wind farm and energy storage in tandem. The system's frequency support requirement can then be calculated from this difference and the minimum support time. Based on the difference between the frequency support requirement and the wind farm's own frequency regulation capability, the required reserved capacity of the energy storage system is calculated to achieve reliable frequency support prevention and control through the tandem operation of the wind farm and energy storage.

[0068] S501, Frequency-Supported Energy Demand Calculation. The system in... The total frequency support energy required by wind farms and energy storage in tandem within a given time period For the system's maximum power deficit and the system's maximum allowable unbalanced power The difference between the shortest support time and the shortest support time The product of: (30) S502. Calculation of the reserved energy required for the energy storage system. The energy required by the energy storage system. To support energy demand for total frequency Subtract the maximum frequency regulation energy that the wind farm can provide : (31) like and This indicates that the wind farm's own frequency regulation capability is sufficient to meet the frequency support requirements, and minimum energy storage can be configured.

[0069] S503, Energy storage reserved capacity configuration. Based on the calculations... Based on the discharge efficiency, maximum discharge power, and other characteristics of the energy storage system, the required rated capacity or power capacity of the energy storage system is determined. For battery energy storage systems, their energy capacity is directly related to... Related to, while power capacity is related to or energy storage system in It is related to the instantaneous peak power required internally.

[0070] In another embodiment of the present invention, a preventive control system for wind farms and energy storage to provide frequency support in synergy is provided. This system can be used to implement the above-mentioned preventive control method for wind farms and energy storage to provide frequency support in synergy. Specifically, the preventive control system for wind farms and energy storage to provide frequency support in synergy includes a construction module, a synthesis module, an optimization module, a calculation module, and a control module.

[0071] Among them, the construction module establishes a wind turbine wake model to describe the wake effect between wind turbines in a wind farm; The synthesis module, based on the wind turbine wake model, uses a quadratic synthesis method to calculate the wind speed distribution of the wind farm under multi-wind turbine coupling; The optimization module calculates the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode based on the wind speed distribution and through the optimization model. The calculation module calculates the maximum power deficit of the system based on the linear frequency components after system disturbance. The control module configures the reserved capacity of the energy storage system to provide frequency support in a coordinated manner, based on the maximum frequency support capacity limit and the maximum power deficit, combined with the maximum unbalanced power allowed by the system and the shortest support time.

[0072] This invention provides a terminal device comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to achieve corresponding method flows or corresponding functions. The processor described in this embodiment can be used in the operation of a preventive control method that provides frequency support in collaboration between wind farms and energy storage, including: A wind turbine wake model is established to describe the wake effect between wind turbines in a wind farm. Based on the wind turbine wake model, the wind speed distribution of the wind farm under multi-turbine coupling is calculated using a quadratic synthesis method. According to the wind speed distribution, the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode is calculated by optimizing the model. Based on the linear frequency component after system disturbance, the maximum power deficit of the system is calculated. According to the upper limit of the maximum frequency support capacity and the maximum power deficit, combined with the maximum unbalanced power and the shortest support time allowed by the system, the reserved capacity of the energy storage system is configured to provide frequency support in a coordinated manner.

[0073] Please see Figure 5 The terminal device is a computer device. In this embodiment, the computer device 60 includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When executed by the processor 61, the computer program 63 implements the method for estimating the concentration of radioactive iodine species in the containment structure after an accident, as described in this embodiment. To avoid repetition, these details are not elaborated here. Alternatively, when executed by the processor 61, the computer program 63 implements the functions of each model / unit in the preventive control system that provides frequency support in collaboration between wind farms and energy storage, as described in this embodiment. To avoid repetition, these details are not elaborated here.

[0074] Computer device 60 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. Computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will understand that... Figure 5 This is merely an example of computer device 60 and does not constitute a limitation on computer device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, computer device may also include input / output devices, network access devices, buses, etc.

[0075] The processor 61 may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0076] The memory 62 can be an internal storage unit of the computer device 60, such as a hard disk or RAM of the computer device 60. The memory 62 can also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., provided on the computer device 60.

[0077] Furthermore, the memory 62 may include both internal storage units of the computer device 60 and external storage devices. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 can also be used to temporarily store data that has been output or will be output.

[0078] Please see Figure 6 The terminal device is an electronic device 600, which is manifested in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including storage unit 620 and processing unit 610), a display unit 640, etc.

[0079] The storage unit stores program code, which can be executed by the processing unit 610 to perform the steps described in the method section of this specification according to various exemplary embodiments of the present invention. For example, the processing unit 610 can perform, as follows: Figure 1 The steps are shown in the figure.

[0080] Storage unit 620 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 6201 and / or cache memory 6202, and may further include a read-only memory (ROM) 6203.

[0081] Storage unit 620 may also include a program / utility 6204 having a set (at least one) program module 6205, such program module 6205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0082] Bus 630 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the multiple bus structures.

[0083] Electronic device 600 can also communicate with one or more external devices 700 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 600, and / or with any device that enables electronic device 600 to communicate with one or more other computing devices (e.g., router, modem). This communication can be performed via input / output interface 650. Furthermore, electronic device 600 can also communicate with one or more networks (e.g., local area network, wide area network, and / or public network, such as the Internet) via network adapter 660. Network adapter 660 can communicate with other modules of electronic device 600 via bus 630. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0084] Example 4 This invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium here can include both built-in storage media in the terminal device and extended storage media supported by the terminal device; it can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor, which can be one or more computer programs (including program code). More specific examples of the computer-readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical fiber, portable compact disk read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0085] Computer-readable storage media also include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium can also be any readable medium other than a readable storage medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium can be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, radio frequency, etc., or any suitable combination thereof.

[0086] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0087] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the preventive control method for frequency support provided by wind farms and energy storage in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps: A wind turbine wake model is established to describe the wake effect between wind turbines in a wind farm. Based on the wind turbine wake model, the wind speed distribution of the wind farm under multi-turbine coupling is calculated using a quadratic synthesis method. According to the wind speed distribution, the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode is calculated by optimizing the model. Based on the linear frequency component after system disturbance, the maximum power deficit of the system is calculated. According to the upper limit of the maximum frequency support capacity and the maximum power deficit, combined with the maximum unbalanced power and the shortest support time allowed by the system, the reserved capacity of the energy storage system is configured to provide frequency support in a coordinated manner.

[0088] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0089] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0090] Please see Figure 2 , Figure 2 This is a schematic diagram of the Jensen-Gaussian wake model. The wake velocity exhibits a radial Gaussian component with a strong central deficit, which more accurately characterizes the actual wake structure and avoids the overestimation error of the linear model. The significant wind speed loss in the axial region explains the root cause of the reduced frequency regulation capability of compact wind farms and guides the optimization of wind turbine layout. The Gaussian distribution is superior to the uniform distribution assumption, providing high-precision input for optimizing the frequency support capability of wind farms under load reduction mode.

[0091] Please see Figure 3 , Figure 3 In the middle (a) and (b), the wind farm was tested at a wind direction of [missing information]. and The wind speed distribution at that time. This wind farm is laid out in a compact 5×5 configuration, with each wind turbine spaced 200m laterally and 100m longitudinally. The wind direction is... At that time, the downstream wind turbine was completely blocked by the upstream wind turbine, resulting in a significant wind speed loss due to the wake effect; the wind direction was... At times, there is partial obstruction.

[0092] Please see Figure 4 , Figure 4 (a) and (b) show the rotor speed and output power of the wind turbines in the wind farm under MPPT and unloaded modes, respectively. The wind farm layout is a 5×5 distribution with each wind turbine spaced 300m apart horizontally and vertically. The minimum rotor speed of the wind turbines is... In MPPT mode, the rotor kinetic energy that the wind farm can release for frequency support during the transient process is... In the unloaded mode, the upstream wind turbine rotor speed unaffected by the wake reaches the upper limit of 1.2 pu, while the rotor speed of the turbine most severely affected by the wake effect is 0.95 pu. The upper limit of rotor kinetic energy that the wind farm can release for frequency support during the transient process is... The reserved energy required for energy storage is calculated according to equation (31).

[0093] Please refer to Table 1, which shows the parameters of the wind turbines and their wake models in the test wind farm.

[0094] Table 1

[0095] Please refer to Table 2, which shows the parameters of the wind farm under overspeed load reduction mode.

[0096] Table 2

[0097] In summary, this invention provides a preventive control method and system for wind farms and energy storage to collaboratively provide frequency support. It establishes a Jensen-Gaussian wake model and determines the wind speed coupling distribution. By optimizing the model, it characterizes the frequency regulation capability of a wind farm considering the wake effect under load reduction mode, calculates the system's maximum power deficit, and, combined with the minimum support time specified by the power grid, determines the required reserved energy storage capacity, thus forming a preventive control strategy for wind farms and energy storage to collaboratively provide frequency support.

[0098] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0099] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0100] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0101] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0102] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0103] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0104] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random-access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0105] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A preventive control method for wind farms and energy storage to collaboratively provide frequency support, characterized in that, Includes the following steps: A wind turbine wake model is established to describe the wake effect between wind turbines in a wind farm. Based on the aforementioned wind turbine wake model, the wind speed distribution of the wind farm under multi-wind turbine coupling is calculated using the quadratic synthesis method. Based on the wind speed distribution, the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode is calculated by an optimization model. Calculate the maximum power deficit of the system based on the linear frequency components after system disturbance; Based on the maximum frequency support capacity limit and the maximum power deficit, combined with the maximum unbalanced power allowed by the system and the shortest support time, the reserved capacity of the energy storage system is configured to provide frequency support in a coordinated manner.

2. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 1, characterized in that, The expression for the wind turbine wake model is: in, The axial inductance coefficient, For the environment's free wind speed, The wake expansion coefficient; The rotor radius at the direct downstream boundary of the wind turbine. Wake boundary, x downstream distance, Radial distance, Losing money due to speed The velocity is the wake velocity.

3. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 1, characterized in that, The characteristics of the wind speed distribution model were calculated using the quadratic synthesis method. Perform coordinate transformation on any point within the wind farm, and calculate the wake effect of each wind turbine as the center; When the corresponding point is affected by the wake of the wind turbine, the wind speed loss value is calculated according to the wake model. The wind speed loss values ​​of all wind turbines are synthesized in a secondary manner to obtain the point. The wind speed at the location was used to calculate the active power output of a single wind turbine.

4. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 3, characterized in that, Wind speed loss value for: in, The coordinates are after rotation. Corresponding to downstream distance, The radial distance corresponding to the axis. Wake boundary, This represents the wind speed loss under coordinate rotation.

5. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 3, characterized in that, point wind speed at the location for: in, For the environment's free wind speed, This is the fan serial number. This represents the total number of wind turbines. For the wind turbine i Points caused Wind speed loss value.

6. The prevention and control method for wind farms and energy storage to collaboratively provide frequency support according to claim 1, characterized in that, The maximum frequency support capacity of the wind farm under the load reduction mode was calculated by optimizing the model. The optimization model is as follows: in, For frequency regulation energy of wind farms; For wind turbine i Releaseable rotor kinetic energy; For wind turbine i The mechanical power of the wind turbine; For active power commands of wind farms; For wind turbine i The pitch angle; and respectively wind turbine i Tip speed ratio and rotor speed in overspeed unloading mode; and respectively wind turbine i The load reduction rate and the maximum load reduction rate.

7. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 1, characterized in that, The maximum power deficit of the calculated system is as follows: Real-time local frequency measurement; time series of measured frequency deviations { , ,…, The linear components are extracted using least-squares fitting; the linear coefficients of the local frequencies are obtained through least-squares fitting. And sine parameters, based on the total inertia of the system Quickly calculate the system power imbalance ; Offline simulation analysis was performed on the most severe N-1 fault scenario of the system to determine the maximum power deficit of the system. .

8. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 1, characterized in that, The reserved capacity of the energy storage system is as follows: set up Indicates the shortest time required for the wind farm to provide frequency support, the system in The total frequency support energy required by wind farms and energy storage in tandem within a given time period The maximum power deficit of the system and the system's maximum allowable unbalanced power The difference between the shortest support time and the shortest support time The product; Energy storage system needs to provide energy To support energy demand for total frequency Subtract the maximum frequency regulation energy that the wind farm can provide Based on the obtained maximum frequency modulation energy Based on the discharge efficiency and maximum discharge power of the energy storage system, the required rated capacity or power capacity of the energy storage system is determined.

9. The prevention and control method for wind farm and energy storage to provide frequency support in synergy according to claim 8, characterized in that, like and This indicates that the wind farm's own frequency regulation capability is sufficient to meet the frequency support requirements, and minimum energy storage can be configured.

10. A preventive control system that coordinates wind farm and energy storage to provide frequency support, characterized in that, include: The module is built to establish a wind turbine wake model, which is used to describe the wake effect between wind turbines in a wind farm; The synthesis module, based on the wind turbine wake model, uses a quadratic synthesis method to calculate the wind speed distribution of the wind farm under multi-wind turbine coupling; The optimization module calculates the upper limit of the maximum frequency support capacity of the wind farm under the load reduction mode based on the wind speed distribution and through the optimization model. The calculation module calculates the maximum power deficit of the system based on the linear frequency components after system disturbance. The control module configures the reserved capacity of the energy storage system to provide frequency support in a coordinated manner, based on the maximum frequency support capacity limit and the maximum power deficit, combined with the maximum unbalanced power allowed by the system and the shortest support time.

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