A control method of a hybrid wind farm and related devices

Abstract

The application relates to the technical field of power control, and provides a control method for a hybrid wind farm and related equipment, the method comprising the following steps: obtaining operation parameters of a target hybrid wind farm; calculating a plurality of frequency parameters of the target hybrid wind farm based on the operation parameters, and calculating an out-of-limit margin of each frequency parameter; determining a final frequency limited type of the target hybrid wind farm from a plurality of frequency limited types according to all the out-of-limit margins; setting control parameters of the target hybrid wind farm based on the operation parameters according to the target frequency limited type, so as to obtain final control parameters; and controlling the target hybrid wind farm by using the final control parameters. The method can improve the control precision of the hybrid wind farm.

Description

Technical Field

[0001] This application relates to the field of power technology, and in particular to a control method and related equipment for a hybrid wind farm. Background Technology

[0002] As the proportion of new energy sources such as wind power continues to increase, the capacity ratio of traditional synchronous generator units in the power system is decreasing, and the system's equivalent inertia and primary frequency regulation capability are weakened accordingly. When the system experiences a sudden increase in load, power deficit, or fluctuations in wind power, the system frequency may experience problems such as an increased rate of frequency change, a lower minimum frequency point, and an increased steady-state frequency deviation.

[0003] Grid-connected doubly-fed induction generators (DFIGs) typically use grid voltage and frequency as a reference, injecting controlled current into the grid through a converter. Their frequency support capability mainly relies on frequency measurement and additional power control. Grid-independent DFIGs, on the other hand, exhibit voltage source characteristics, actively participating in frequency support through virtual inertia, virtual damping, and primary frequency regulation control. Hybrid DFIG wind farms, incorporating both grid-connected and grid-independent DFIGs, can balance the utilization of existing grid-connected units with the support capability of grid-independent units, thus gradually becoming an important form of high-proportion renewable energy systems.

[0004] Existing technologies have enabled the establishment of frequency response models for hybrid wind farms and the determination of frequency regulation parameters for grid-connected and grid-joined wind turbines through optimization algorithms, thereby improving the system's frequency response. However, relying solely on optimization algorithms typically yields only one set of optimized parameters, making it difficult to determine the dominant cause of frequency performance degradation, or to differentiate whether the current system is limited by the maximum rate of frequency change, the steady-state deviation of the frequency response, the maximum frequency deviation, or multiple performance indicators simultaneously.

[0005] Furthermore, increasing the proportion of grid-connected doubly-fed induction generators (DFIGs) does not necessarily lead to a simultaneous improvement in all frequency indicators. The maximum rate of frequency change is mainly related to the total wind power capacity ratio and the equivalent inertia of synchronous turbines; the steady-state deviation of the frequency response is affected by the coupling influence of the grid-connected DFIG capacity ratio, the grid-connected DFIG capacity ratio, the grid-connected droop coefficient, and the grid-connected primary frequency regulation coefficient; the maximum frequency deviation is also affected by the grid-connected DFIG capacity ratio, the virtual inertia time constant, and the virtual damping coefficient. Therefore, if different frequency-limited types are not differentiated based on mechanistic relationships, and instead the proportion of grid-connected DFIGs is blindly increased or global optimization parameters are uniformly adopted, one frequency indicator may improve while another deteriorates, resulting in low control accuracy in hybrid wind farms. Summary of the Invention

[0006] This application provides a control method and related equipment for hybrid wind farms, which can solve the problem of low control accuracy in hybrid wind farms.

[0007] In a first aspect, embodiments of this application provide a control method for a hybrid wind farm, including: Obtain the operating parameters of the target hybrid wind farm; the operating parameters include the total wind power capacity ratio, the primary frequency regulation coefficient of the grid-connected doubly-fed induction generator (DFIG) and the droop coefficient of the grid-connected DFIG. Calculate multiple frequency parameters of the target hybrid wind farm based on operating parameters, and calculate the over-limit margin for each frequency parameter; the over-limit margin is used to describe the degree to which the frequency parameter deviates from the preset limit; Based on all over-limit margins, determine the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types; Based on the target frequency-limited type, the control parameters of the target hybrid wind farm are tuned according to the operating parameters to obtain the final control parameters; The target hybrid wind farm is controlled using the final control parameters.

[0008] Optional, multiple frequency parameters include maximum frequency change rate, steady-state frequency response deviation, and maximum frequency deviation; Multiple frequency parameters of the target hybrid wind farm are calculated based on operating parameters, including: Construct the system frequency response transfer function of the target hybrid wind farm based on operating parameters; Calculate the maximum rate of change of frequency, steady-state deviation of frequency response, and maximum frequency deviation based on the system frequency response transfer function.

[0009] Optionally, calculate the over-limit margin for each frequency parameter, including: Through the formula:

[0010] Calculate the over-limit margin of the maximum rate of change of frequency. ; in, This indicates the maximum rate of change limit of frequency. Indicates the maximum rate of change of frequency; Through the formula:

[0011] Calculate the over-limit margin of steady-state deviation of frequency response ; in, This indicates the steady-state deviation limit of the frequency response. Indicates the steady-state deviation of the frequency response; Through the formula:

[0012] Calculate the over-limit margin for the maximum frequency deviation ; in, This indicates the maximum frequency deviation limit. This indicates the maximum frequency deviation.

[0013] Optionally, multiple frequency limiting types include maximum frequency change rate limiting type, frequency response steady-state deviation limiting type, maximum frequency deviation limiting type, and composite limiting type; Based on all over-limit margins, the final frequency-limited type of the target hybrid wind farm is determined from multiple frequency-limited types, including: when , and At that time, the final frequency-limited type of the target hybrid wind farm is the maximum frequency change rate-limited type; when , and At that time, the final frequency-constrained type of the target hybrid wind farm is the frequency response steady-state deviation-constrained type; when , and At that time, the final frequency-limited type of the target hybrid wind farm is the maximum frequency deviation-limited type; when , , When at least two values ​​are less than 0, the final frequency-confined type of the target hybrid wind farm is a composite-confined type.

[0014] Optionally, based on the target frequency-constrained type, the control parameters of the target hybrid wind farm are tuned according to the operating parameters to obtain the final control parameters, including: Based on the target frequency-limited type, a corresponding parameter tuning strategy is defined. The control parameters of the target hybrid wind farm are tuned based on the parameter tuning strategy and the operating parameters to obtain the final control parameters.

[0015] Optionally, when the target frequency limitation type is the maximum frequency change rate limitation type, the control parameters include wind power output ratio, wind power reserve capacity, and synchronous turbine operating capacity, and the parameter tuning strategy is as follows: The upper limit of the total wind power capacity ratio is calculated based on operating parameters; Determine whether the total wind power capacity ratio of the target hybrid wind farm is greater than or equal to the upper limit of the total wind power capacity ratio. If so, the parameters for wind power output ratio and wind power reserve capacity are adjusted according to the preset ascending gradient, and the parameters for synchronous unit operating capacity are adjusted according to the preset descending gradient.

[0016] Optionally, when the target frequency limitation type is frequency response steady-state deviation limitation type, the control parameters include at least one of the following: grid-connected doubly-fed induction generator (DFIG) capacity ratio, grid-connected DFIG capacity ratio, grid-connected DFIG primary frequency regulation coefficient, and grid-connected DFIG droop coefficient. The parameter tuning strategy is as follows: If the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine is greater than the droop coefficient of the grid-type doubly-fed wind turbine, then the capacity ratio of the grid-type doubly-fed wind turbine is adjusted according to the preset ascending gradient. If the primary frequency regulation coefficient of the grid-type doubly fed fan is less than the droop coefficient of the grid-type doubly fed fan, then the capacity ratio of the grid-type doubly fed fan is adjusted according to the preset rise gradient. If the primary frequency regulation coefficient of the grid-type doubly-fed induction generator is equal to the droop coefficient of the grid-type doubly-fed induction generator, then the primary frequency regulation coefficient of the grid-type doubly-fed induction generator and the droop coefficient of the grid-type doubly-fed induction generator are jointly tuned.

[0017] Optionally, when the target frequency limitation type is the maximum frequency deviation limitation type, the control parameter is one of the following: the capacity ratio of the grid-type doubly-fed induction generator (TFIG), the virtual inertia time constant of the grid-type TFIG, the virtual damping coefficient of the grid-type TFIG, the sag coefficient of the grid-fed TFIG, the inertia coefficient of the grid-fed TFIG, and the primary frequency regulation coefficient of the grid-type TFIG. The parameter tuning strategy is as follows: Calculate the capacity ratio of the grid-type doubly-fed induction generator (DFIG), the virtual inertia time constant of the grid-type DFIG, the virtual damping coefficient of the grid-type DFIG, the sag coefficient of the grid-fed DFIG, the inertia coefficient of the grid-fed DFIG, and the sensitivity of the primary frequency regulation coefficient of the grid-type DFIG. The parameter with the highest sensitivity is used as the control parameter, and the control parameter is tuned.

[0018] Secondly, embodiments of this application provide a control device for a hybrid wind farm, comprising: The acquisition module is used to acquire the operating parameters of the target hybrid wind farm; the operating parameters include the total wind power capacity ratio, the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine, and the droop coefficient of the grid-connected doubly-fed wind turbine. The calculation module is used to calculate multiple frequency parameters of the target hybrid wind farm based on the operating parameters, and to calculate the over-limit margin of each frequency parameter; the over-limit margin is used to describe the degree to which the frequency parameter deviates from the preset limit; The determination module is used to determine the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types based on all over-limit margins; The tuning module is used to tune the control parameters of the target hybrid wind farm based on the operating parameters according to the target frequency-limited type, so as to obtain the final control parameters; The control module is used to control the target hybrid wind farm using the final control parameters.

[0019] Thirdly, embodiments of this application provide a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned control method for a hybrid wind farm.

[0020] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned control method for a hybrid wind farm.

[0021] The above-mentioned solution in this application has the following beneficial effects: In the embodiments of this application, the operating parameters of the target hybrid wind farm are obtained, and then multiple frequency parameters of the target hybrid wind farm are calculated based on the operating parameters. The over-limit margin for each frequency parameter is calculated, and then, based on all over-limit margins, the final frequency-limited type of the target hybrid wind farm is determined from multiple frequency-limited types. Then, based on the target frequency-limited type, the control parameters of the target hybrid wind farm are tuned according to the operating parameters to obtain the final control parameters. Finally, the target hybrid wind farm is controlled using the final control parameters. Specifically, calculating the over-limit margin reflects the frequency deviation of the target hybrid wind farm. Tuning the control parameters based on the final frequency-limited type determined by the over-limit margin identifies the deviation of the frequency response index and enables corresponding parameter tuning for different frequency-limited scenarios, improving the accuracy and rationality of the control parameters, thereby improving the control precision of the hybrid wind farm.

[0022] Other beneficial effects of this application will be described in detail in the following detailed description section. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A flowchart illustrating a control method for a hybrid wind farm provided in an embodiment of this application; Figure 2 This is a schematic diagram of the restricted type identification process provided in an embodiment of this application; Figure 3 A schematic diagram illustrating the degree of influence of various factors on frequency indicators provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the parameter tuning process provided in an embodiment of this application; Figure 5This is a schematic diagram of a closed-loop verification process provided in an embodiment of this application; Figure 6 This is a schematic diagram of the frequency response curve provided in an embodiment of this application; Figure 7 A schematic diagram of the structure of a control device for a hybrid wind farm provided in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0025] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0026] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0027] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0029] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0031] To address the issue of low control accuracy in existing hybrid wind farms, this application provides a control method for hybrid wind farms. This method acquires the operating parameters of the target hybrid wind farm, calculates multiple frequency parameters based on these parameters, and calculates the over-limit margin for each frequency parameter. Then, based on all over-limit margins, it determines the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types. Next, based on the target frequency-limited type, it tunes the control parameters of the target hybrid wind farm according to the operating parameters to obtain the final control parameters. Finally, it uses these final control parameters to control the target hybrid wind farm. The calculated over-limit margin reflects the frequency deviation of the target hybrid wind farm. Tuning the control parameters based on the final frequency-limited type determined by the over-limit margin identifies the deviation of the frequency response index and enables corresponding parameter tuning for different frequency-limited scenarios, improving the accuracy and rationality of the control parameters, thereby enhancing the control accuracy of the hybrid wind farm.

[0032] The control method for hybrid wind farms provided in this application will be described by way of example below.

[0033] like Figure 1 As shown, the control method for a hybrid wind farm provided in this application includes the following steps: Step 11: Obtain the operating parameters of the target hybrid wind farm.

[0034] The aforementioned target hybrid wind farm refers to a hybrid wind farm that requires control. A hybrid wind farm includes both grid-connected and grid-fed wind turbines. The aforementioned operating parameters include the proportion of total wind power capacity at the current moment. L total Primary frequency regulation coefficient of grid-type doubly fed wind turbine k w sag coefficient of grid-type doubly fed wind turbine k p This also includes the ratio of grid-type doubly fed wind turbine capacity. L 1. Capacity ratio of grid-type doubly-fed wind turbines L2. Equivalent inertial time constant of synchronous generator units H SG Damping coefficient of synchronous generator unit D SG , Load mutation amount Δ P L Inertia coefficient of grid-type doubly fed wind turbine k d Power response delay of grid-type doubly-fed wind turbines T d Virtual inertia time constant of grid-type doubly fed wind turbine H GFM Virtual damping coefficient of grid-type doubly fed wind turbine D GFM Power angle to output electromagnetic power gain K G Mechanical power gain coefficient K m The proportion of power generation by the high-pressure cylinder of the steam turbine F HP Reheating time constant T R and the reciprocal of the speed controller gain coefficient R eq wait.

[0035] The total wind power capacity ratio refers to the proportion of the rated capacity of each type of wind turbine in a hybrid wind farm to the total wind power capacity of the entire farm. The primary frequency regulation coefficient of a grid-connected doubly-fed induction generator (DFIG) refers to the ratio of the active power regulation to the grid frequency deviation when the DFIG participates in the primary frequency regulation of the grid. The droop coefficient of a grid-connected DFIG refers to the ratio of the change in active power of the turbine to the change in system frequency in the droop control of the grid-connected DFIG.

[0036] **Grid-connected Doubly Fed Induction Generator (DFIG) Capacity Ratio:** The ratio of the total rated capacity of grid-connected DFIGs in a hybrid wind farm to the total rated capacity of the entire farm's wind power. **Grid-connected DFIG Capacity Ratio:** The ratio of the total rated capacity of grid-connected DFIGs in a hybrid wind farm to the total rated capacity of the entire farm's wind power. **Synchronous Generator Equivalent Inertia Time Constant:** An equivalent time parameter characterizing the ability of a synchronous generator rotor to store rotational kinetic energy and resist sudden changes in system frequency. **Synchronous Generator Damping Coefficient:** The power-speed ratio coefficient by which a synchronous generator suppresses oscillations between generator speed and grid frequency using damping windings. **Load Fluctuation:** The instantaneous increase or decrease in active power load in the grid, representing the amplitude of system power disturbance. **Grid-connected DFIG Inertia Coefficient:** The ratio of active power regulation to the rate of frequency change when a grid-connected DFIG simulates the inertial response of a synchronous generator. **Grid-connected DFIG Power Response Delay:** The time lag between the detection of a frequency disturbance and the output of frequency-modulated active power by a grid-connected DFIG. Virtual inertia time constant of a grid-type doubly-fed induction generator (DFIG): The equivalent time constant used in the virtual synchronous control of a grid-type DFIG to simulate the inertial energy storage characteristics of the rotor. Virtual damping coefficient of a grid-type DFIG: The active power-frequency difference proportionality coefficient used in the virtual synchronous control of a grid-type DFIG to suppress frequency oscillations.

[0037] In some embodiments of this application, the operating parameters may come from the wind farm energy management system, wind turbine main control system, grid controller, grid-connecting controller, synchronous unit speed governor parameter library, power grid dispatching system, wide area measurement system, or offline planning simulation model of the target hybrid wind farm.

[0038] Step 12: Calculate multiple frequency parameters of the target hybrid wind farm based on the operating parameters, and calculate the over-limit margin for each frequency parameter.

[0039] The aforementioned frequency parameters include the maximum rate of frequency change, steady-state deviation of frequency response, and maximum frequency deviation. The aforementioned over-limit margin is used to describe the degree to which the frequency parameters deviate from the preset limit.

[0040] In some embodiments of this application, the steps of calculating multiple frequency parameters of the target hybrid wind farm based on operating parameters and calculating the over-limit margin of each frequency parameter include: The first step is to construct the system frequency response transfer function of the target hybrid wind farm based on the operating parameters.

[0041] The system frequency response transfer function is used to describe the relationship between the frequency change of a hybrid wind farm and the power change corresponding to grid-connected wind turbines, grid-connected wind turbines, and synchronous turbines.

[0042] Specifically, the system frequency response transfer function is:

[0043] in, Indicates the amount of sudden change in load. This represents the change in system frequency. All are intermediate parameters:

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] The second step is to calculate the maximum rate of change of frequency, steady-state deviation of frequency response, and maximum frequency deviation based on the system frequency response transfer function.

[0053] For example, based on the system frequency response transfer function, the maximum rate of change of frequency, the steady-state deviation of frequency response, and the maximum frequency deviation are calculated using the following expressions:

[0054]

[0055] in, Indicates the maximum rate of change of frequency. This indicates the steady-state deviation of the frequency response.

[0056] Maximum frequency deviation It can be obtained by performing an inverse Laplace transform on the system's frequency response transfer function and finding the frequency extrema.

[0057] The third step is to calculate the over-limit margin for each frequency parameter.

[0058] Specifically, through the formula:

[0059] Calculate the over-limit margin of the maximum rate of change of frequency. .

[0060] in, This indicates the maximum rate of change limit of frequency. This represents the maximum rate of change of frequency.

[0061] Through the formula:

[0062] Calculate the over-limit margin of steady-state deviation of frequency response .

[0063] in, This indicates the steady-state deviation limit of the frequency response. This indicates the steady-state deviation of the frequency response.

[0064] Through the formula:

[0065] Calculate the over-limit margin for the maximum frequency deviation .

[0066] in, This indicates the maximum frequency deviation limit. This indicates the maximum frequency deviation.

[0067] It should be noted that when a certain margin is less than 0, it indicates that the corresponding frequency safety index has exceeded the limit. 、 、 The value is not fixed and is generally determined by the power grid company, dispatching procedures, or grid connection technical requirements.

[0068] Step 13: Based on all over-limit margins, determine the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types.

[0069] The aforementioned frequency-limited types include maximum frequency change rate-limited, frequency response steady-state deviation-limited, maximum frequency deviation-limited, and combined-limited types.

[0070] The maximum frequency change rate-limited type refers to the maximum frequency change rate exceeding the system limit; the frequency steady-state deviation-limited type refers to the frequency steady-state deviation exceeding the system limit; the maximum frequency deviation-limited type refers to the maximum frequency deviation exceeding the system limit; and the combined-limited type refers to more than two of the following indicators exceeding the system limit: maximum frequency change rate, frequency steady-state deviation, and maximum frequency deviation.

[0071] Specifically, when , and At that time, the final frequency-limited type of the target hybrid wind farm is the maximum frequency change rate-limited type.

[0072] when , and At that time, the final frequency-constrained type of the target hybrid wind farm is the frequency response steady-state deviation constrained type.

[0073] when , and At that time, the final frequency-limited type of the target hybrid wind farm is the maximum frequency deviation-limited type.

[0074] when , , When at least two of the values ​​are less than 0, the final frequency-confined type of the target hybrid wind farm is a composite-confined type.

[0075] For example, if none of the above conditions are met, the current target hybrid wind farm can be considered to require no parameter tuning and can be continuously controlled according to the current control parameters. The frequency-limited type determination is shown in Table 1.

[0076] Table 1

[0077] when M R , M S and M T When all values ​​are greater than or equal to 0, the current operating scheme or planning scheme is determined to meet the preset frequency safety limit, and the current network capacity configuration and frequency regulation parameters are maintained.

[0078] In some embodiments of this application, the process for identifying restricted types is as follows: Figure 2 As shown, after starting, the three frequency indicators ROCOFmax, SSDOF, and TMDOF are calculated first, and then the formula is used. , , Solve for the corresponding safety margins separately; then judge them sequentially. <0、 <0、 If the condition is true, the corresponding ROCOF restricted flag, SSDOF restricted flag, and TMDOF restricted flag are assigned a value of 1; otherwise, they are assigned a value of 0. After assigning the flags, the total number of restricted flags N is counted, and the types are divided according to N: N=0 is unrestricted, N=1 is single restricted, and N≥2 is composite restricted. Finally, the frequency restricted type is output, and the process ends.

[0079] The influence of various factors on frequency indicators, such as Figure 3 As shown in the figure, the rows are different frequency indicators, and the columns are different factors. Black dots indicate that the factors have a major impact on the frequency indicators, round dots indicate that the factors have a minor impact on the frequency indicators, and horizontal bars indicate that the factors have little impact on the frequency indicators.

[0080] Step 14: Based on the target frequency-limited type, the control parameters of the target hybrid wind farm are tuned according to the operating parameters to obtain the final control parameters.

[0081] The aforementioned final control parameters are parameters in the target hybrid wind farm at the next time step from the current time step, such as the wind power output ratio, wind power reserve capacity, synchronous turbine operating capacity, grid-connected doubly-fed induction generator (DFIG) capacity ratio, grid-connected DFIG capacity ratio, grid-connected DFIG primary frequency regulation coefficient, and grid-connected DFIG droop coefficient, etc.

[0082] Specifically, a corresponding parameter tuning strategy is defined based on the target frequency-constrained type. The control parameters of the target hybrid wind farm are tuned based on the parameter tuning strategy and the operating parameters to obtain the final control parameters. That is, based on the operating parameters at the current moment, the control parameters at the current moment are tuned using the parameter tuning strategy, and the tuned control parameters are the final control parameters.

[0083] When the target frequency limitation type is the maximum frequency change rate limitation type, the control parameters include the wind power output ratio, wind power reserve capacity, and synchronous turbine operating capacity. The parameter tuning strategy is as follows: The first step is to calculate the upper limit of the total wind power capacity ratio based on the operating parameters.

[0084] Specifically, through the formula:

[0085] Calculate the upper limit of the total wind power capacity ratio .

[0086] in, Indicates the amount of sudden change in load. This indicates the maximum rate of change limit of frequency. This represents the equivalent inertial time constant of a synchronous generator unit.

[0087] The second step is to determine whether the proportion of total wind power capacity in the target hybrid wind farm is greater than or equal to the upper limit of the proportion of total wind power capacity.

[0088] If so, the parameters for wind power output ratio and wind power reserve capacity are adjusted according to the preset ascending gradient, and the parameters for synchronous unit operating capacity are adjusted according to the preset descending gradient.

[0089] For example, the sum of the wind power output ratio and the preset upward gradient is calculated to obtain the adjusted wind power output ratio; the sum of the wind power reserve capacity and the preset upward gradient is calculated to obtain the adjusted wind power reserve capacity; and the difference between the synchronous turbine operating capacity and the preset downward gradient is calculated to obtain the adjusted synchronous turbine operating capacity.

[0090] For example, as can be seen from the formula for calculating the maximum rate of change of frequency, in H SG and Δ P L At a given time, the maximum rate of change of frequency is mainly determined by the proportion of total wind power capacity. L total Decision. When L total When the wind power capacity increases, the proportion of synchronous turbines decreases, the system's equivalent inertia support becomes insufficient, and the absolute value of the maximum frequency change rate increases. If the above conditions are met, the primary cause is determined to be insufficient total wind power capacity proportion or insufficient equivalent inertia support. Strategies prioritizing the output of total wind power capacity proportion constraints, increasing equivalent inertia support, increasing the participation rate of synchronous turbines, or increasing wind power reserve capacity are then implemented. If the above conditions are not met, parameter tuning is unnecessary, and the target hybrid wind farm can be continuously controlled according to the current control parameters.

[0091] When the target frequency limitation type is frequency response steady-state deviation limitation type, the control parameters include at least one of the following: grid-connected doubly-fed induction generator (DFIG) capacity ratio, grid-connected DFIG capacity ratio, grid-connected DFIG primary frequency regulation coefficient, and grid-connected DFIG droop coefficient. The parameter tuning strategy is as follows: If the primary frequency regulation coefficient of the grid-type doubly-fed induction generator is greater than the droop coefficient of the grid-type doubly-fed induction generator, then the capacity ratio of the grid-type doubly-fed induction generator is adjusted according to the preset ascending gradient.

[0092] If the primary frequency regulation coefficient of the grid-type doubly-fed induction generator is less than the droop coefficient of the grid-type doubly-fed induction generator, then the capacity ratio of the grid-type doubly-fed induction generator is adjusted according to the preset ascending gradient.

[0093] If the primary frequency regulation coefficient of the grid-type doubly-fed induction generator is equal to the droop coefficient of the grid-type doubly-fed induction generator, then the primary frequency regulation coefficient of the grid-type doubly-fed induction generator and the droop coefficient of the grid-type doubly-fed induction generator are jointly tuned.

[0094] For example, the sum of the capacity ratio of the grid-type doubly-fed induction generator (TFIG) and the preset rise gradient can be calculated to obtain the adjusted capacity ratio of the grid-type TFIG. Similarly, the sum of the capacity ratio of the follow-grid type TFIG and the preset rise gradient can be calculated to obtain the adjusted capacity ratio of the follow-grid type TFIG.

[0095] During joint tuning, if the steady-state frequency deviation margin MS is less than 0, the required supplementary equivalent frequency regulation support is calculated based on the difference between the current steady-state frequency response deviation and the preset limit. Since the steady-state frequency deviation is mainly caused by the following factors when the total wind power capacity ratio remains constant... k w L 2 R eq and k pL 1 R eq It was jointly decided that the required additional frequency regulation support would be allocated to the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine. k w and the sag coefficient of the grid-type doubly fed wind turbine k p.

[0096] Let the required supplemental equivalent frequency modulation support be Δ. D , k p The adjustment amount is Δ k p , k w The adjustment amount is Δ k w Then the parameter adjustment result should satisfy: Δ k p L 1 R eq+Δ k w L 2 R eq ≥Δ D .

[0097] In one implementation, the allocation coefficient α is determined based on the available reserve capacity of the grid-connected and grid-connected doubly-fed wind turbines, where 0 ≤ α ≤ 1. The frequency regulation support allocated to the grid-connected doubly-fed wind turbine is α × Δ. D The frequency regulation support allocated to the grid-type doubly fed wind turbine is (1-α)Δ D And based on this, determine Δ respectively k p and Δ k w .

[0098] After completing the parameter adjustment, determine the adjusted result. k p and k w Does it meet the upper limit of controller parameters, the standby power constraint of the wind turbine, and the system stability constraint? If it does, then adjust the... k p and k w The recommended value is sent to the corresponding wind turbine controller; if it is not met, then... k p and k w Limit the amplitude and further increase the standby capacity or adjust the capacity ratio of grid-connected doubly-fed wind turbines to grid-connected doubly-fed wind turbines until MS is greater than or equal to 0, or the preset maximum number of settings is reached.

[0099] From the formula for calculating the steady-state deviation of the frequency response, it can be seen that when L total When kept constant, the key term affecting the steady-state deviation of the frequency response is k w L 2 R eq + k p L 1 R eq This item reflects the coupling relationship between the primary frequency regulation coefficient of the grid-type doubly-fed induction generator (DFIG), the droop coefficient of the grid-type DFIG, and the capacity ratio of the two types of fans. The variation law of SSDOF is shown in Table 2.

[0100] Table 2

[0101] Let n = L 1 / L 2. When k w = k p hour, k w L 2 R eq + k p L 1 R eq Can be transformed into k p ( L 1+ L 2) R eq Therefore, the steady-state deviation of the frequency response does not change with... L 1 and L The ratio changes with 2. At this point, if... M S <0, should be prioritized for joint improvement k p and k w Or increase standby capacity, rather than simply adjusting... L 1 / L 2.

[0102] when k w > k p When, as n= L 1 / L As 2 increases, the proportion of grid-type doubly-fed wind turbines decreases, and the steady-state deviation of the frequency response deteriorates; therefore, ifM S <0, should be prioritized for reduction L 1 / L 2, or improve L 2. Improve k w .

[0103] when k w < k p When, as n= L 1 / L 2. As the proportion of grid-type doubly-fed wind turbines increases, the steady-state deviation of the frequency response improves; therefore, if M S If <0, it should be increased first. L 1 / L 2, or improve L 1. Improve k p .

[0104] The above criteria can prevent blindly increasing the proportion of grid-type doubly-fed wind turbines in scenarios where steady-state frequency deviation is limited.

[0105] When the target frequency limitation type is the maximum frequency deviation limitation type, the control parameter is one of the following: the capacity ratio of the grid-type doubly-fed induction generator (DFIG), the virtual inertia time constant of the grid-type DFIG, the virtual damping coefficient of the grid-type DFIG, the sag coefficient of the grid-fed DFIG, the inertia coefficient of the grid-fed DFIG, and the primary frequency regulation coefficient of the grid-type DFIG. The parameter tuning strategy is as follows: The first step is to calculate the sensitivity of the capacity ratio of the grid-type doubly-fed induction generator (DFIG), the virtual inertia time constant of the grid-type DFIG, the virtual damping coefficient of the grid-type DFIG, the sag coefficient of the grid-fed DFIG, the inertia coefficient of the grid-fed DFIG, and the primary frequency regulation coefficient of the grid-type DFIG.

[0106] For example, through the formula:

[0107]

[0108] Calculation parameters Sensitivity .

[0109] Among them, parameters The value is one of the following: capacity ratio of grid-type doubly-fed induction generator (DFIG), virtual inertia time constant of grid-type DFIG, virtual damping coefficient of grid-type DFIG, sag coefficient of grid-fed DFIG, inertia coefficient of grid-fed DFIG, and primary frequency regulation coefficient of grid-type DFIG. Indicates the maximum frequency deviation. Indicates parameters The change in S. Tj If the value is greater than 0, then increase by x. j This will increase the maximum frequency deviation; if S T,j If the value is less than 0, then increase by x. j This will reduce the maximum frequency deviation.

[0110] To uniformly identify the dominant influencing factors of the three frequency indicators, a frequency support mechanism sensitivity matrix S is constructed:

[0111] Where, x j include L total , L 1. L 2. k p , k d , k w , H GFM and D GFM At least one of them. To eliminate dimensional differences, for S ij Normalization is performed to obtain the normalized sensitivity S. ij *:

[0112] When a certain frequency indicator exceeds the limit, select S in the corresponding row of that indicator. ij One or more parameters with the largest influence are selected as dominant influencing factors, and adjustment strategies are generated preferentially for these parameters. The impact of influencing factors on frequency indicators is shown in Table 3.

[0113] Table 3

[0114] The second step is to select the parameter with the highest sensitivity as the control parameter and then tune the control parameter.

[0115] For example, if the sensitivity corresponding to the control parameter is positive, the parameter is reduced or its upper limit is limited according to a preset descending gradient to obtain the tuned control parameter; if the sensitivity corresponding to the control parameter is negative, the parameter is increased or its lower limit is expanded according to a preset ascending gradient to obtain the tuned control parameter.

[0116] In one implementation, for H GFM and D GFMSet stability constraints and controller output constraints to prevent excessive virtual inertia or virtual damping adjustments from causing controller oscillation, power over-limit, or secondary frequency drops.

[0117] It should be noted that, for the case of a combined restricted frequency response, the corrections should be made in the following order of priority: maximum frequency change rate, maximum frequency deviation, and steady-state frequency response deviation. First, the maximum frequency change rate limit should be met to prevent a rapid frequency drop in the initial stage of the disturbance. Second, the maximum frequency deviation limit should be met to prevent the frequency from exceeding the limit at its lowest point. Finally, the steady-state frequency deviation limit should be met to improve the frequency recovery quality.

[0118] After each priority parameter adjustment is completed, recalculate. M R , M S and M T If the correction causes other frequency indicators to exceed the limit, the frequency-limited type identification process will be restarted until all three margins meet the requirements or the preset maximum number of iterations is reached.

[0119] For example, the parameter tuning process in this step is as follows: Figure 4 As shown, taking the frequency-limited type as input, it is divided into four branches: ROCOFmax-limited, SSDOF-limited, TMDOF-limited, and combined-limited, each implementing a corresponding adjustment strategy: If it is the ROCOFmax-limited type, the total load is limited. Optimization methods include reducing the proportion of wind power output, increasing system inertia support, and configuring reserve capacity; if it is an SSDOF-constrained type, first determine... k w and k p Numerical relationships, k w ≠ k p Time priority adjustment k w or L 2, k w < k p Time priority adjustment k p or L 1, k w = k p Simultaneous improvement k w and k p Alternatively, increase reserve capacity; if it is a TMDOF-restricted type, reduce it first. L2. Reduce D GFM Reselect under stability constraints H GFM The optimization sequence is as follows: for composite constrained types, the priority is followed by sequential correction, first satisfying the ROCOFmax constraint, then the TMDOF constraint, and finally the SSDOF constraint; after all four types of branches have completed parameter adjustments, a unified network / network structure capacity configuration strategy and frequency modulation parameter tuning strategy are generated, and the final output is... L 1. L 2. k p , k d , k w , H GFM , D GFM Recommended value.

[0120] Step 15: Control the target hybrid wind farm using the final control parameters.

[0121] Specifically, at the next moment after the current moment, the parameters of the target hybrid wind farm are adjusted to the final control parameters using the control system of the target hybrid wind farm, thereby achieving control of the target hybrid wind farm.

[0122] For example, the recommended values ​​for the capacity ratio of grid-type doubly-fed wind turbines and the recommended values ​​for the capacity ratio of grid-type doubly-fed wind turbines... k p , k d , k w , H GFM and D GFM At least one of the parameters is sent to the wind farm controller. The wind farm controller sends the corresponding parameters to the grid-following wind turbine (GFL-WT) controller and the grid-forming wind turbine (GFM-WT) controller, respectively, according to the turbine type.

[0123] For online control scenarios, after the data is sent out, the frequency response data after the disturbance is collected, and ROCOFmax, SSDOF, and TMDOF are recalculated. If all three over-limit margins are greater than or equal to 0, the current parameters are maintained; if any over-limit margin is less than 0, the mechanism criterion is reconstructed and a new parameter adjustment strategy is generated.

[0124] For planning and design scenarios, output a grid-based retrofit plan. This retrofit plan includes the proportion of capacity to be converted to grid-based doubly-fed wind turbines, the proportion of capacity to be retained as grid-fed doubly-fed wind turbines, the recommended range of control parameters for grid-based and grid-fed wind turbines, and the recommended value of reserve capacity.

[0125] For example, the closed-loop verification process is as follows: Figure 5 As shown, with the upper-level strategy decision module as the core, after the module completes the identification of frequency-limited types, generation of capacity configuration strategies, and generation of frequency modulation parameter tuning strategies, it synchronously outputs three types of instructions: issuing commands to the GFL-WT controller. k p , k d Parameters are sent to the grid-connected doubly-fed wind turbine group and distributed to the GFM-WT controller. k w , H GFM , D GFM Parameters are sent to the grid-type doubly-fed wind turbine group, and output to the operation adjustment / modification execution unit containing... L 1. L The 2-level grid / network capacity configuration scheme supports on-site operation adjustments or grid-based transformation; after the wind turbine group and execution unit are deployed and controlled, the data is sent to the frequency response feedback acquisition module to collect various operating data such as system frequency, ROCOFmax, SSDOF, TMDOF, and wind turbine output; the collected data is then transmitted to the over-limit margin recalculation and strategy update module, which calculates... M R , M S , M T It then determines whether it is necessary to re-identify the restricted type and update the control strategy. The updated strategy is then sent back to the upper-level strategy decision module, forming a complete closed-loop control process.

[0126] It is worth mentioning that the calculated over-limit margin reflects the frequency deviation of the target hybrid wind farm. Based on the final frequency-limited type determined by the over-limit margin, the control parameters are tuned to identify the deviation of the frequency response index and to perform corresponding parameter tuning for different frequency-limited scenarios, thereby improving the accuracy and rationality of the control parameters and thus improving the control precision of the hybrid wind farm.

[0127] The method of this application will be illustrated below with a specific example.

[0128] To verify the effectiveness of the proposed method, a frequency response model of a hybrid doubly-fed wind farm, including grid-connected doubly-fed wind turbines, grid-connected doubly-fed wind turbines, and synchronous turbines, was established in a simulation platform. The same load surge disturbance was set in the simulation, and comparisons were made using the original parameter scheme, a scheme that simply increases the capacity ratio of the grid-connected doubly-fed wind turbines, and the tuning scheme of the proposed method. The system frequency response curves were recorded under the same simulation conditions for all three schemes, and the maximum rate of change of frequency (ROCOFmax), steady-state frequency response deviation (SSDOF), and maximum frequency deviation (TMDOF) were calculated.

[0129] In this embodiment, a maximum frequency change rate limit R is set. lim =0.5Hz / s, steady-state deviation of frequency response S lim =0.2Hz, maximum frequency deviation limit T lim =0.5Hz. According to M R =R lim -|ROCOFmax|、 M S =S lim -|SSDOF| and M T = T lim -|TMDOF| calculates the maximum frequency change margin, the steady-state frequency response deviation margin, and the maximum frequency deviation margin, respectively. When M R , M S and M T If all values ​​are greater than or equal to 0, the corresponding scheme is determined to meet the preset frequency safety limit.

[0130] Frequency response curve as shown Figure 6 As shown, Figure 6 The horizontal axis represents time, and the vertical axis represents the system frequency in Hertz. The load disturbance is performed at 30 seconds. The curves are the frequency response curves of the tuning scheme of this application, the frequency response curve of the scheme of simply increasing the purchase ratio of the grid, and the frequency response curve of the original parameter scheme.

[0131] Table 4 shows a comparison of the frequency response indicators of hybrid doubly fed wind farms under different schemes.

[0132] Table 4

[0133] Under the original parameter scheme, ROCOFmax is 0.453Hz / s, SSDOF is 0.236Hz, and TMDOF is 0.462Hz, corresponding to... M R =0.047、 MS =-0.036、 M T =0.038. Because M S A value less than 0 indicates that the original parameter scheme belongs to the type with limited steady-state deviation in frequency response. Under the scheme of simply increasing the proportion of grid-type doubly-fed induction generator (DFIG) capacity, ROCOFmax is 0.457Hz / s, SSDOF is 0.236Hz, and TMDOF is 0.466Hz, corresponding to... M R =0.043、 M S =-0.036、 M T =0.034. Although this scheme changes the capacity ratio of the grid-type doubly fed wind turbines, it still does not eliminate the problem of frequency response steady-state deviation exceeding the limit, and the maximum frequency change rate and maximum frequency deviation index are slightly worse than the original parameter scheme.

[0134] After adopting the method of this application, the current frequency limitation type is first identified as frequency response steady-state deviation limitation type based on the over-limit margin; then, based on the frequency response steady-state deviation criterion, combined with the capacity ratio of grid-connected doubly-fed induction generators, the capacity ratio of grid-connected doubly-fed induction generators, and the droop coefficient of grid-connected doubly-fed induction generators, the method is applied. k p The primary frequency regulation coefficient of the grid-type doubly fed wind turbine k w The coupling relationship between them is used to generate corresponding network capacity configuration strategies and frequency modulation parameter tuning strategies. After tuning, ROCOFmax decreases to 0.394Hz / s, SSDOF decreases to 0.196Hz, and TMDOF decreases to 0.399Hz, corresponding to... M R =0.106、 M S =0.004、 M T =0.101, all three margins are greater than or equal to 0, which meets the preset frequency safety limit.

[0135] The simulation results show that simply increasing the proportion of grid-connected doubly-fed induction generator (DFIG) wind turbines does not guarantee an improvement in all frequency response indicators, and may even slightly worsen the maximum frequency change rate and maximum frequency deviation. However, the method proposed in this application can identify the frequency-limited type based on the over-limit margin and adjust the grid capacity configuration and frequency regulation parameters accordingly, ensuring that ROCOFmax, SSDOF, and TMDOF all meet the preset frequency safety limits. Therefore, the method proposed in this application can transform the frequency support mechanism analysis results into executable capacity configuration and parameter tuning steps, improving the targeting and effectiveness of frequency response control in hybrid DFIG wind farms.

[0136] The control device for the hybrid wind farm provided in this application will be described below as an example.

[0137] like Figure 7 As shown in the figure, this application embodiment provides a control device for a hybrid wind farm. The control device 700 includes: The acquisition module 701 is used to acquire the operating parameters of the target hybrid wind farm; the operating parameters include the total wind power capacity ratio, the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine, and the droop coefficient of the grid-connected doubly-fed wind turbine. The calculation module 702 is used to calculate multiple frequency parameters of the target hybrid wind farm based on the operating parameters, and to calculate the over-limit margin of each frequency parameter; the over-limit margin is used to describe the degree to which the frequency parameter deviates from the preset limit value; The determination module 703 is used to determine the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types based on all over-limit margins; The tuning module 704 is used to tune the control parameters of the target hybrid wind farm based on the operating parameters according to the target frequency-limited type, so as to obtain the final control parameters; Control module 705 is used to control the target hybrid wind farm using the final control parameters.

[0138] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0139] 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.

[0140] like Figure 8 As shown, an embodiment of this application provides a terminal device, wherein the terminal device D10 of this embodiment includes: at least one processor D100 ( Figure 8The diagram shows only one processor, a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100, wherein the processor D100 executes the computer program D102 to implement the steps in any of the above method embodiments.

[0141] Specifically, when the processor D100 executes the computer program D102, it acquires the operating parameters of the target hybrid wind farm, then calculates multiple frequency parameters of the target hybrid wind farm based on the operating parameters, calculates the over-limit margin for each frequency parameter, and then determines the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types based on all over-limit margins. Then, based on the target frequency-limited type, it tunes the control parameters of the target hybrid wind farm based on the operating parameters to obtain the final control parameters. Finally, it uses the final control parameters to control the target hybrid wind farm. The calculation of the over-limit margin reflects the frequency deviation of the target hybrid wind farm. The control parameter tuning based on the final frequency-limited type determined by the over-limit margin identifies the deviation of the frequency response index and enables corresponding parameter tuning for different frequency-limited scenarios, improving the accuracy and rationality of the control parameters, thereby improving the control precision of the hybrid wind farm.

[0142] The processor D100 can be a central processing unit (CPU), or it can be other general-purpose processors, 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 can be a microprocessor or any conventional processor.

[0143] In some embodiments, the memory D101 may be an internal storage unit of the terminal device D10, such as a hard disk or memory of the terminal device D10. In other embodiments, the memory D101 may be an external storage device of the terminal device D10, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the terminal device D10. Furthermore, the memory D101 may include both internal and external storage units of the terminal device D10. The memory D101 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory D101 can also be used to temporarily store data that has been output or will be output.

[0144] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0145] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the steps described in the various method embodiments above.

[0146] If the integrated 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 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 at least: any entity or device capable of carrying computer program code to the control method apparatus / terminal equipment of a hybrid wind farm, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0147] 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.

[0148] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein 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 implementation should not be considered beyond the scope of this application.

[0149] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles described in this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A control method for a hybrid wind farm, characterized in that, include: Obtain the operating parameters of the target hybrid wind farm; the operating parameters include the total wind power capacity ratio, the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine, and the droop coefficient of the grid-connected doubly-fed wind turbine; Based on the operating parameters, multiple frequency parameters of the target hybrid wind farm are calculated, and the over-limit margin of each frequency parameter is calculated; the over-limit margin is used to describe the degree to which the frequency parameter deviates from the preset limit. Based on all over-limit margins, determine the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types; Based on the target frequency-limited type, the control parameters of the target hybrid wind farm are tuned according to the operating parameters to obtain the final control parameters; The target hybrid wind farm is controlled using the final control parameters.

2. The control method according to claim 1, characterized in that, The multiple frequency parameters include the maximum rate of frequency change, the steady-state deviation of the frequency response, and the maximum frequency deviation; The calculation of multiple frequency parameters of the target hybrid wind farm based on the operating parameters includes: Construct the system frequency response transfer function of the target hybrid wind farm based on the operating parameters; Calculate the maximum rate of change of frequency, steady-state deviation of frequency response, and maximum frequency deviation based on the system frequency response transfer function.

3. The control method according to claim 2, characterized in that, The calculation of the over-limit margin for each frequency parameter includes: Through the formula: Calculate the over-limit margin of the maximum rate of change of frequency. ; in, This indicates the maximum rate of change limit of frequency. Indicates the maximum rate of change of frequency; Through the formula: Calculate the over-limit margin of steady-state deviation of frequency response ; in, This indicates the steady-state deviation limit of the frequency response. Indicates the steady-state deviation of the frequency response; Through the formula: Calculate the over-limit margin for the maximum frequency deviation ; in, This indicates the maximum frequency deviation limit. This indicates the maximum frequency deviation.

4. The control method according to claim 3, characterized in that, The multiple frequency limiting types include maximum frequency change rate limiting type, frequency response steady-state deviation limiting type, maximum frequency deviation limiting type, and composite limiting type; The determination of the final frequency-limited type of the target hybrid wind farm from multiple frequency-limited types based on all over-limit margins includes: when , and At that time, the final frequency-limited type of the target hybrid wind farm is the maximum frequency change rate-limited type; when , and At that time, the final frequency-limited type of the target hybrid wind farm is the frequency response steady-state deviation-limited type; when , and At that time, the final frequency-limited type of the target hybrid wind farm is the maximum frequency deviation-limited type; when , , When at least two of the values ​​are less than 0, the final frequency-confined type of the target hybrid wind farm is a composite-confined type.

5. The control method according to claim 4, characterized in that, The step of tuning the control parameters of the target hybrid wind farm based on the target frequency-limited type and the operating parameters to obtain the final control parameters includes: Based on the target frequency-limited type, a corresponding parameter tuning strategy is defined. The control parameters of the target hybrid wind farm are tuned based on the parameter tuning strategy and the operating parameters to obtain the final control parameters.

6. The control method according to claim 5, characterized in that, When the target frequency limitation type is the maximum frequency change rate limitation type, the control parameters include wind power output ratio, wind power reserve capacity, and synchronous turbine operating capacity, and the parameter tuning strategy is as follows: The upper limit of the total wind power capacity ratio is calculated based on operating parameters; Determine whether the total wind power capacity ratio of the target hybrid wind farm is greater than or equal to the upper limit of the total wind power capacity ratio; If so, the parameters for wind power output ratio and wind power reserve capacity are adjusted according to the preset ascending gradient, and the parameters for synchronous unit operating capacity are adjusted according to the preset descending gradient.

7. The control method according to claim 5, characterized in that, When the target frequency limitation type is frequency response steady-state deviation limitation type, the control parameters include at least one of the following: grid-connected doubly-fed induction generator (DFIG) capacity ratio, grid-connected DFIG capacity ratio, grid-connected DFIG primary frequency regulation coefficient, and grid-connected DFIG droop coefficient. The parameter tuning strategy is as follows: If the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine is greater than the droop coefficient of the grid-type doubly-fed wind turbine, then the capacity ratio of the grid-type doubly-fed wind turbine is adjusted according to the preset ascending gradient. If the primary frequency regulation coefficient of the grid-type doubly-fed wind turbine is less than the droop coefficient of the grid-type doubly-fed wind turbine, then the capacity ratio of the grid-type doubly-fed wind turbine is adjusted according to the preset ascending gradient. If the primary frequency regulation coefficient of the grid-type doubly-fed induction generator is equal to the droop coefficient of the grid-type doubly-fed induction generator, then the primary frequency regulation coefficient of the grid-type doubly-fed induction generator and the droop coefficient of the grid-type doubly-fed induction generator are jointly tuned.

8. The control method according to claim 5, characterized in that, When the target frequency limitation type is the maximum frequency deviation limitation type, the control parameter is one of the following: the capacity ratio of the grid-type doubly-fed induction generator (TFIG), the virtual inertia time constant of the TFIG, the virtual damping coefficient of the TFIG, the sag coefficient of the grid-fed TFIG, the inertia coefficient of the grid-fed TFIG, and the primary frequency regulation coefficient of the TFIG. The parameter tuning strategy is as follows: Calculate the capacity ratio of the grid-type doubly-fed induction generator (DFIG), the virtual inertia time constant of the grid-type DFIG, the virtual damping coefficient of the grid-type DFIG, the sag coefficient of the grid-fed DFIG, the inertia coefficient of the grid-fed DFIG, and the sensitivity of the primary frequency regulation coefficient of the grid-type DFIG. The parameter with the highest sensitivity is used as the control parameter, and the control parameter is tuned.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the control method for a hybrid wind farm as described in any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the control method for a hybrid wind farm as described in any one of claims 1 to 8.

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