Energy storage coupling wind turbine generator frequency modulation method and device

Abstract

The invention discloses an energy storage coupling wind turbine generator frequency modulation method and device, and the method comprises the steps: obtaining a grid-connected point frequency value of a wind turbine generator; determining whether the grid-connected point frequency value satisfies a coordination control strategy condition; if the grid-connected point frequency value meets a coordination control strategy condition, determining target active power based on an optimal frequency modulation model; and based on the target active power, regulating and controlling the frequency of the power grid by coupling the energy storage system with the wind turbine generator. Therefore, on the basis of the optimal frequency modulation model, the target active power is determined through coordination of the energy storage system and the wind turbine generator, and the frequency of the power grid is regulated and controlled on the basis of the target active power, so that active power support is performed on the power grid, and a power system is enabled to operate safely and stably.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine control, and in particular to a frequency modulation method and device for an energy storage coupled wind turbine. Background Art

[0002] At present, the characteristics of the power grid will change after wind power is connected to the grid. Since the wind turbine power electronic equipment is connected to the grid, it is sensitive to the frequency fluctuation of the grid. Based on this, the power system needs to regulate large-scale grid-connected wind power to ensure the safe and stable operation of the power system. However, since wind power output is affected by the current wind speed, the ability of wind turbines to participate in the frequency regulation of the power system is limited and uncertain. Based on this, how the energy storage system coordinates with wind turbines to ensure the support of the frequency of the grid is an urgent problem to be solved. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, the present invention proposes a frequency regulation method for energy storage-coupled wind turbines, which can determine the target active power through the coordination between the energy storage system and the wind turbines based on the optimal frequency regulation model, and regulate the frequency of the power grid based on the target active power, thereby providing active power support for the power grid and ensuring safe and stable operation of the power system.

[0005] Another object of the present invention is to provide an energy storage coupled wind turbine frequency regulation device.

[0006] To achieve the above object, the present invention provides a frequency modulation method for energy storage coupled wind turbine generator set, the method comprising:

[0007] Obtain the grid connection point frequency value of the wind turbine;

[0008] Determining whether the grid connection point frequency value satisfies the coordinated control strategy conditions;

[0009] If the grid connection point frequency value meets the coordinated control strategy conditions, the target active power is determined based on the optimal frequency modulation model;

[0010] Based on the target active power, the frequency of the power grid is regulated by coupling the energy storage system with the wind turbine generator set.

[0011] The energy storage coupled wind turbine frequency modulation method of the embodiment of the present invention may also have the following additional technical features:

[0012] In one embodiment of the present invention, determining whether the grid connection point frequency value satisfies the coordinated control strategy condition includes:

[0013] Determining whether the grid connection point frequency value exceeds a corresponding preset threshold;

[0014] If the grid connection point frequency value exceeds the corresponding preset threshold, it is determined that the grid connection point frequency value meets the coordination control strategy conditions.

[0015] In one embodiment of the present invention, determining the target active power based on the optimal frequency modulation model includes:

[0016] Determining the energy storage coupled wind turbine objective function of the optimal frequency regulation model;

[0017] Determine a plurality of constraint conditions corresponding to the objective function of the energy storage coupled wind turbine generator set;

[0018] The target active power is obtained by performing optimization calculation on the objective function of the energy storage coupled wind turbine set and the multiple constraint conditions through the grey wolf algorithm.

[0019] In one embodiment of the present invention, the multiple constraints include: voltage constraints, active power constraints, frequency deviation constraints, speed constraints, stability constraints, energy storage constraints, energy storage charge state constraints and energy storage active power constraints.

[0020] In one embodiment of the present invention, the determining of the multiple constraints corresponding to the objective function of the energy storage coupled wind turbine generator set includes:

[0021] Determine the stability value of the current power system;

[0022] Based on the stability value, a stability constraint condition corresponding to the objective function of the energy storage coupled wind turbine generator set is determined.

[0023] In one embodiment of the present invention, determining the stability value of the power system includes:

[0024] Establishing a frequency and voltage regulation model for the power system;

[0025] Determining a state matrix based on the power system frequency and voltage regulation model;

[0026] Based on the state matrix, a stability value of the power system is determined.

[0027] To achieve the above object, the present invention provides, on the other hand, a frequency modulation device for energy storage coupled wind turbine generator set, the device comprising:

[0028] An acquisition module is used to obtain the grid connection point frequency value of the wind turbine generator set;

[0029] A first determination module is used to determine whether the frequency value of the grid connection point meets the coordination control strategy conditions;

[0030] A second determination module is used to determine the target active power based on the optimal frequency modulation model if the grid connection point frequency value meets the coordinated control strategy conditions;

[0031] The control module is used to control the frequency of the power grid by coupling the energy storage system with the wind turbine generator set based on the target active power.

[0032] In one embodiment of the present invention, the first determining module is specifically configured to:

[0033] Determining whether the grid connection point frequency value exceeds a corresponding preset threshold;

[0034] If the grid connection point frequency value exceeds the corresponding preset threshold, it is determined that the grid connection point frequency value meets the coordination control strategy conditions.

[0035] Another object of the present invention is to provide an electronic device, comprising:

[0036] at least one processor; and

[0037] a memory communicatively connected to the at least one processor; wherein,

[0038] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform any one of the methods described in the above aspect.

[0039] Another object of the present invention is to provide a computer storage medium, wherein the computer storage medium stores computer executable instructions; after the computer executable instructions are executed by a processor, the computer executes any one of the methods described in the above aspect.

[0040] The energy storage-coupled wind turbine frequency regulation method and device of the embodiment of the present invention can determine the target active power based on the optimal frequency regulation model through the coordination between the energy storage system and the wind turbine, and based on the target active power, regulate the frequency of the power grid, thereby providing active power support for the power grid, so that the power system can operate safely and stably.

[0041] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0043] Figure 1 is a flow chart of a frequency modulation method for an energy storage coupled wind turbine generator set according to an embodiment of the present invention;

[0044] Figure 2 4 is a structural diagram of an energy storage coupled wind turbine frequency modulation device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] The following describes the energy storage coupled wind turbine frequency modulation method and device according to the embodiments of the present invention with reference to the accompanying drawings.

[0048] Figure 1 It is a flow chart of the frequency modulation method of the energy storage coupled wind turbine generator set according to an embodiment of the present invention.

[0049] like Figure 1 As shown, the method includes:

[0050] S1, obtaining the grid connection point frequency value of the wind turbine generator;

[0051] In one embodiment of the present invention, the grid connection point frequency value of the wind turbine generator system may be acquired based on a sensor at the grid connection point.

[0052] S2, determine whether the frequency value of the grid connection point meets the coordinated control strategy conditions;

[0053] In one embodiment of the present invention, after the grid connection point frequency value is obtained through the above steps, it can be determined whether the grid connection point frequency value meets the coordinated control strategy conditions based on the grid connection point frequency value to determine whether to perform coordinated control.

[0054] Specifically, in one embodiment of the present invention, the method for determining whether the grid connection point frequency value satisfies the coordinated control strategy conditions may include: determining whether the grid connection point frequency value exceeds the corresponding preset threshold value; if the grid connection point frequency value exceeds the corresponding preset threshold value, then determining that the grid connection point frequency value satisfies the coordinated control strategy conditions; if the grid connection point frequency value does not exceed the corresponding preset threshold value, then determining that the grid connection point frequency value does not satisfy the coordinated control strategy conditions and no control is required.

[0055] S3, if the frequency value of the grid connection point meets the conditions of the coordinated control strategy, the target active power is determined based on the optimal frequency regulation model;

[0056] In one embodiment of the present invention, if the frequency value of the grid connection point meets the coordinated control strategy conditions, the target active power can be determined based on the optimal frequency regulation model, thereby achieving active support for the frequency of the power grid.

[0057] In one embodiment of the present invention, the method for determining the target active power based on the optimal frequency modulation model may include the following steps:

[0058] S31, determining the objective function of the energy storage coupled wind turbine generator set of the optimal frequency regulation model;

[0059] S32, determining multiple constraint conditions corresponding to the objective function of the energy storage coupled wind turbine generator set;

[0060] S33, the target active power is obtained by optimizing the objective function and multiple constraints of the energy storage coupled wind turbine set through the Grey Wolf Algorithm.

[0061] In one embodiment of the present invention, the energy storage coupled wind turbine target function can be determined by taking the maximum value of the active power of the energy storage system and the active power of the wind turbine as the goal. Specifically, in one embodiment of the present invention, the energy storage coupled wind turbine target function can be:

[0062] fitness=max(P sup_w +P sup_s )

[0063] Among them, P sup_w is the active power of wind turbines participating in grid frequency regulation, P sup_s is the active power of the energy storage system participating in the grid frequency regulation. Among them, H w and H g is the inertia constant of the wind turbine and energy storage system, ω r is the speed of the wind turbine, K d These are the parameters of the fan frequency controller.

[0064] And, in one embodiment of the present invention, the above-mentioned multiple constraints may include: voltage constraints, active power constraints, frequency deviation constraints, speed constraints, stability constraints, energy storage constraints, energy storage charge state constraints and energy storage active power constraints.

[0065] In one embodiment of the present invention, the voltage constraint condition and the active power constraint condition among the multiple constraint conditions may be determined based on the maximum voltage, the maximum active power, and the maximum reactive power in the power system.

[0066] Specifically, in one embodiment of the present invention, the voltage constraint condition is: U sup ≤U max , where U sup is the voltage compensation value required for reactive power compensation, U max is the maximum voltage value.

[0067] In one embodiment of the present invention, the above active power constraint condition is: (P sup +P s )≤P w_max , where P sup is the active power compensation, P s is the active power value, P w_max is the maximum active power.

[0068] In one embodiment of the present invention, the frequency deviation constraint condition is: |Δf|<±0.05, which means that the amplitude of the frequency deviation of the wind turbine grid connection point is less than or equal to 0.05 Hz.

[0069] In one embodiment of the present invention, the above speed constraint condition is: r_min ≤ω r ≤ω r_max ,ω r_min and ω r_max The upper and lower boundary values ​​of the fan speed.

[0070] In one embodiment of the present invention, the energy storage constraint condition is: [SOC(t)-SOC(t-1)]·E s =P(t)·Δt, where E s is the capacity of the energy storage system, which is usually 5% to 10% of the rated power of the wind turbine. Δt is the time for frequency regulation of the system.

[0071] In one embodiment of the present invention, the above energy storage state of charge constraint condition is: SOC min ≤SOC≤SOC max , SOC min and SOC max are the upper and lower boundary values ​​of the energy storage charge state.

[0072] In one embodiment of the present invention, the above energy storage active power constraint condition is:

[0073] In one embodiment of the present invention, the method for determining the multiple constraints corresponding to the objective function of the energy storage coupled wind turbine may include: determining the stability constraints of the objective function of the energy storage coupled wind turbine. In one embodiment of the present invention, the method for determining the stability constraints of the objective function of the energy storage coupled wind turbine may include: determining the stability value of the current power system, and determining the stability constraints corresponding to the objective function of the energy storage coupled wind turbine based on the stability value.

[0074] In one embodiment of the present invention, the method for determining the stability value of the current power system may include the following steps:

[0075] Step a, establishing a frequency and voltage regulation model for the power system;

[0076] Step b: determining a state matrix based on a frequency and voltage regulation model of a power system;

[0077] Step c: Based on the state matrix, determine the stability value of the power system.

[0078] In one embodiment of the present invention, the above-mentioned power system frequency regulation and voltage regulation model may be:

[0079]

[0080] in, represents the differential of the power system state variable x, A represents the state matrix of the power system, B represents the input matrix, C represents the output matrix, D represents the direct transfer matrix, y represents the output, and u represents the system input.

[0081] Furthermore, in one embodiment of the present invention, by calculating the above-mentioned frequency regulation and voltage regulation model of the power system, the state matrix A of the power system can be determined.

[0082] Further, in one embodiment of the present invention, after determining the state matrix A through the above steps, the stability value of the power system can be determined based on the state matrix. In one embodiment of the present invention, the stability value of the power system can be determined by a stability formula, wherein the stability formula is:

[0083] λ=eig(A)

[0084] Among them, λ is the stability value of the power system, and eig represents the characteristic value to be solved.

[0085] Further, in one embodiment of the present invention, after determining the stability value of the current power system through the above steps, the stability constraint condition corresponding to the objective function of the energy storage coupled wind turbine can be determined according to the stability value as follows:

[0086] |ζ(λsys )|≥0.15

[0087] Among them, λ sys =λ=σ±jω is the characteristic root of the system, is the damping ratio.

[0088] Furthermore, in one embodiment of the present invention, after determining the objective function of the energy storage-coupled wind turbine group and the corresponding multiple constraints of the optimal frequency regulation model through the above steps, the objective function of the energy storage-coupled wind turbine group and the multiple constraints can be optimized and calculated using the Grey Wolf Algorithm to obtain the target active power.

[0089] Specifically, in one embodiment of the present invention, the update expression of the individual position of the gray wolf in the optimization solution is set as shown in the following equation:

[0090]

[0091] Where t represents the current iteration number; is the current distance between the gray wolf and its prey; and is the step coefficient vector; is the position vector of the prey, and is the energy storage coupled wind turbine objective function of the optimization problem; is the position vector of the gray wolf itself. And, the coefficient vector and The calculation is done by the following formula:

[0092]

[0093] in, is the convergence factor, which decreases linearly from 2 to 0 during the iteration process; is a random vector in [0, 1]. And the model of gray wolf tracking prey position update is shown in the following formula:

[0094]

[0095] in, and Respectively represent the distances between a, b, c and other gray wolf individuals; Indicates the current position of a, b, and c; is a random vector; is the current position of the gray wolf.

[0096]

[0097] in, Indicates the position of the bottom wolf d approaching a, b, and c. Represents the final position of the individual gray wolf d.

[0098] Furthermore, in one embodiment of the present invention, through the above configuration, the method of obtaining the target active power by optimizing the target function and multiple constraints of the energy storage coupled wind turbine using the Grey Wolf Algorithm may include the following steps:

[0099] Step 1: According to the upper and lower bounds of the optimization variable, the initial variables are randomly generated, and the frequency modulation active output is calculated;

[0100] Step 2: Establish gray wolf individuals and populations;

[0101] Step 3, initialize the gray wolf algorithm parameters and population;

[0102] Step 4: Determine whether the current gray wolf meets the constraints. If yes, continue. If not, update the gray wolf according to the corresponding constraints.

[0103] Step 5: Calculate the fitness value of each individual gray wolf by the objective function of the energy storage coupled wind turbine, and find and save the top three gray wolves in fitness;

[0104] Step 6: Update the convergence factor and coefficient vector according to the current number of iterations;

[0105] Step 7: Update the distance between the gray wolf and the prey and the current position of the gray wolf according to the gray wolf algorithm introduced in the previous section and the updated coefficient vector;

[0106] Step 8: Update the top three best gray wolves;

[0107] Step 9: Determine whether the current iterative optimization has reached the maximum number of iterations. If so, end the loop and obtain the target active power; if not, return to step 5 and repeat the above steps until the loop ends and the target active power is obtained.

[0108] S4, based on the target active power, the frequency of the power grid is regulated by coupling the energy storage system with the wind turbines.

[0109] In one embodiment of the present invention, after the target active power is obtained through the above steps, the active power can be adjusted based on the target active power, thereby controlling the current on the wind turbine rotor side, thereby achieving active frequency support of the wind turbine to the power grid.

[0110] In one embodiment of the present invention, the grid connection point frequency value of the wind turbine generator set is obtained; it is determined whether the grid connection point frequency value meets the coordinated control strategy conditions; if the grid connection point frequency value meets the coordinated control strategy conditions, the target active power is determined based on the optimal frequency regulation model; based on the target active power, the frequency of the power grid is regulated by coupling the wind turbine generator set with the energy storage system. Thus, based on the optimal frequency regulation model, the target active power can be determined by the coordination and cooperation between the energy storage system and the wind turbine generator set, and based on the target active power, the frequency of the power grid is regulated, thereby providing active power support for the power grid, so that the power system can operate safely and stably.

[0111] In order to implement the above embodiment, Figure 2 As shown, this embodiment also provides an energy storage coupled wind turbine frequency regulation device 10, which includes an acquisition module 201, a first determination module 202, a second determination module 203 and a control module 204;

[0112] An acquisition module 201 is used to acquire a grid connection point frequency value of a wind turbine generator system;

[0113] The first determination module 202 is used to determine whether the frequency value of the grid connection point meets the coordination control strategy conditions;

[0114] The second determination module 203 is used to determine the target active power based on the optimal frequency modulation model if the frequency value of the grid connection point meets the coordinated control strategy conditions;

[0115] The control module 204 is used to control the frequency of the power grid by coupling the energy storage system with the wind turbine generator system based on the target active power.

[0116] In the embodiment of the present disclosure, the first determining module 202 is specifically used to:

[0117] Determine whether the frequency value of the grid connection point exceeds the corresponding preset threshold;

[0118] If the frequency value of the grid connection point exceeds the corresponding preset threshold, it is determined that the frequency value of the grid connection point meets the coordination control strategy conditions.

[0119] Furthermore, the second determining module 203 is specifically configured to:

[0120] Determine the objective function of energy storage-coupled wind turbines for the optimal frequency regulation model;

[0121] Determine multiple constraints corresponding to the objective function of the energy storage coupled wind turbine;

[0122] The Grey Wolf Algorithm is used to optimize the objective function and multiple constraints of the energy storage coupled wind turbine to obtain the target active power.

[0123] Furthermore, the above-mentioned multiple constraints include: voltage constraints, active power constraints, frequency deviation constraints, speed constraints, stability constraints, energy storage constraints, energy storage charge state constraints and energy storage active power constraints.

[0124] Furthermore, the second determining module 203 is further configured to:

[0125] Determine the stability value of the current power system;

[0126] Based on the stability value, the stability constraint conditions corresponding to the objective function of the energy storage coupled wind turbine are determined.

[0127] Furthermore, the second determining module 203 is further configured to:

[0128] Establish frequency and voltage regulation models for power systems;

[0129] Determine the state matrix based on the power system frequency and voltage regulation model;

[0130] Based on the state matrix, the stability value of the power system is determined.

[0131] According to the energy storage-coupled wind turbine frequency regulation device of an embodiment of the present invention, the device can determine the target active power based on the optimal frequency regulation model through the coordination between the energy storage system and the wind turbine, and based on the target active power, regulate the frequency of the power grid, thereby providing active power support for the power grid, so that the power system can operate safely and stably.

[0132] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0133] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A frequency modulation method for energy storage coupled wind turbine generator set, characterized in that: The method comprises: Obtain the grid connection point frequency value of the wind turbine; Determining whether the grid connection point frequency value satisfies the coordinated control strategy conditions; If the grid connection point frequency value meets the coordinated control strategy conditions, the target active power is determined based on the optimal frequency modulation model; Based on the target active power, the frequency of the power grid is regulated by coupling the energy storage system with the wind turbine generator set.

2. The method according to claim 1, characterized in that The determining whether the grid connection point frequency value and the grid connection point voltage value meet the coordinated control strategy conditions includes: Determining whether the grid connection point frequency value exceeds a corresponding preset threshold; If the grid connection point frequency value exceeds the corresponding preset threshold, it is determined that the grid connection point frequency value meets the coordination control strategy conditions.

3. The method according to claim 1, characterized in that The step of determining the target active power based on the optimal frequency modulation model includes: Determining the energy storage coupled wind turbine objective function of the optimal frequency regulation model; Determining a plurality of constraint conditions corresponding to the objective function of the energy storage coupled wind turbine generator set; The target active power is obtained by performing optimization calculation on the objective function of the energy storage coupled wind turbine set and the multiple constraint conditions through the grey wolf algorithm.

4. The method according to claim 3, characterized in that The multiple constraints include: voltage constraints, active power constraints, frequency deviation constraints, speed constraints, stability constraints, energy storage constraints, energy storage charge state constraints and energy storage active power constraints.

5. The method according to claim 4, characterized in that The determining of the multiple constraint conditions corresponding to the objective function of the energy storage coupled wind turbine generator set includes: Determine the stability value of the current power system; Based on the stability value, a stability constraint condition corresponding to the objective function of the energy storage coupled wind turbine generator set is determined.

6. The method according to claim 5, characterized in that Determining the stability value of the current power system includes: Establishing a frequency and voltage regulation model for the power system; Determining a state matrix based on the power system frequency and voltage regulation model; Based on the state matrix, a stability value of the power system is determined.

7. An energy storage coupled wind turbine frequency modulation device, characterized in that: The device comprises: An acquisition module is used to obtain the grid connection point frequency value of the wind turbine generator set; A first determination module is used to determine whether the frequency value of the grid connection point meets the coordination control strategy conditions; A second determination module is used to determine the target active power based on the optimal frequency modulation model if the grid connection point frequency value meets the coordinated control strategy conditions; The control module is used to control the frequency of the power grid by coupling the energy storage system with the wind turbine generator set based on the target active power.

8. The device according to claim 7, characterized in that The first determining module is specifically configured to: Determining whether the grid connection point frequency value exceeds a corresponding preset threshold; If the grid connection point frequency value exceeds the corresponding preset threshold, it is determined that the grid connection point frequency value meets the coordination control strategy conditions.

9. An electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

10. A computer storage medium, wherein: The computer storage medium stores computer executable instructions; after the computer executable instructions are executed by the processor, the method according to any one of claims 1 to 6 can be implemented.

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