Wind power plant binary admittance aggregation modeling method, system, equipment and medium

Abstract

The invention relates to the technical field of new energy power generation, in particular to a binary admittance aggregation modeling method, system and device for a wind power plant and a medium, and the method comprises the steps: determining an arrangement topological structure between units in a current collection circuit in the wind power plant; selecting a corresponding wake flow model according to the topological structure, and deducing the operation wind speed of each wind turbine generator at any natural wind speed; obtaining the relation between the operation wind speed and the grid-connected power according to the maximum power tracking control; drawing a power flow diagram of the wind power plant according to the relationship, and obtaining a grid-connected point operation working point of each unit through load flow calculation; listing and writing a small signal voltage admittance matrix of a current collection line node containing unit working point information; and solving the voltage admittance matrix to obtain a port admittance aggregation model. According to the method, the relation between the wind speed and the unit working point is determined through the wake flow model and load flow calculation, and aggregation of the binary admittance model of the wind power plant is achieved. And the port frequency domain characteristics of the wind power plant in the whole wind speed interval under the wake effect can be accurately represented.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation technology, and in particular to a method, system, equipment and medium for binary admittance aggregation modeling of wind farms. Background Technology

[0002] With the expansion of wind power installed capacity, oscillation events in wind farm grid-connected systems occur frequently. Among the methods for analyzing the small-signal stability of wind farm grid-connected systems, the impedance method has a clear physical meaning and strong scalability. With its modular architecture and black box modeling characteristics, it has shown significant advantages in the study of wind power system oscillation problems.

[0003] Because wind speed in the environment is constantly changing, and oscillation characteristics are closely related to wind speed, existing research has conducted related analyses. For example, wind farms are treated as equivalent to single wind turbine units, and different grid-connected capacities (wind speeds) are selected to simulate changes in the operating point to study system stability. However, this method can only provide quantitative analysis and cannot reflect the changing patterns of grid-connected stability across the entire wind speed range. When analyzing the impact of wind speed on wind farms, the wake effect and the structure of the collector lines cannot be ignored. While the single-unit equivalent method has low computational complexity, the wind speed differences between units under the wake effect are neglected, making it difficult to accurately describe the impedance characteristics of the wind farm. Therefore, this method still has certain limitations.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a method, system, equipment, and medium for binary admittance aggregation modeling of wind farms, thereby effectively solving the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a method for binary admittance aggregation modeling of wind farms, comprising the following steps:

[0007] Determine the topology of the turbine layout within the collector lines of the wind farm;

[0008] Based on the topology, a corresponding wake model is constructed, and the operating wind speed of each wind turbine under arbitrary natural wind speed is derived.

[0009] The relationship between the operating wind speed and the grid-connected power is obtained based on the Maximum Power Point Tracking (MPPT) control.

[0010] Based on the aforementioned relationship, a power flow diagram of the wind farm is generated, and the operating point of each unit's grid connection is obtained through power flow calculation.

[0011] List the small-signal voltage admittance matrix of the collector line node containing the operating point information of the unit;

[0012] Solving the voltage admittance matrix yields the port admittance aggregation model.

[0013] Furthermore, obtaining the relationship between the operating wind speed and the grid-connected power based on Maximum Power Point Tracking (MPPT) includes:

[0014] P m (v r )=0.5ρπr 2 C p v r 3 ;

[0015] In the formula, P m The wind turbine capture power under MPPT control, ρ is the air density; r is the rotor radius; C p v is the wind energy capture factor. r This refers to wind speed.

[0016] Furthermore, the step of listing the small-signal voltage admittance matrix of the collector node containing the operating point information of the unit includes:

[0017] Based on the grid connection point and operating point of each unit, construct the small-signal equivalent circuit diagram;

[0018] Write the node voltage matrix based on the small-signal equivalent circuit diagram;

[0019] Calculate the voltage admittance matrix based on the node voltage matrix.

[0020] Furthermore, the node voltage matrix is ​​as follows:

[0021]

[0022] In the formula, U n (f p ) and I n (f p ) are respectively f p Voltage and current source vectors at the node at the specified frequency; I cn (f c ) is f c Current source vector flowing into the node at a given frequency; Y n (f p Y is the voltage admittance matrix. n (f c ) is f c Voltage node admittance matrix at frequency, U n (f c ) is f cNode voltage vector at a given frequency.

[0023] Furthermore, the layout topology includes several wind turbines, which are connected to the 35kV bus in a trunk line configuration.

[0024] The present invention also includes a wind farm binary admittance aggregation modeling system, using the method described above, the system comprising:

[0025] The acquisition unit is used to determine the topology of the arrangement of turbines in the collector lines within a wind farm.

[0026] The derivation unit is used to construct the corresponding wake model based on the topology and derive the operating wind speed of each wind turbine under any natural wind speed.

[0027] The MPPT control unit is used to obtain the relationship between the operating wind speed and the grid-connected power based on the maximum power point tracking control of the MPPT.

[0028] The power flow calculation unit is used to generate a power flow diagram of the wind farm based on the aforementioned relationship, and to obtain the operating point of each unit's grid connection point through power flow calculation;

[0029] Admittance matrix unit, used to list the small-signal voltage admittance matrix of the collector line node containing the operating point information of the unit;

[0030] The solver unit is used to solve the voltage admittance matrix to obtain the port admittance aggregation model.

[0031] The present invention also includes a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as described above.

[0032] The present invention also includes a storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described above.

[0033] The beneficial effects of this invention are as follows: Based on the binary admittance model of wind turbine generators, the grid-connected port admittance model of the wind farm is derived according to the topology of the collector lines. The relationship between wind speed and turbine operating point is determined through wake modeling and power flow calculations, thus realizing the aggregation of the binary admittance model of the wind farm. Compared with the single-unit equivalent aggregation method, this method can accurately characterize the port frequency domain characteristics of the wind farm under the wake effect throughout the entire wind speed range. When it is necessary to evaluate the small-signal stability of the wind farm grid-connected system within the entire wind speed range, this method can quantitatively determine the relationship between the stable operating wind speed range of the wind farm and the stability of wind speed and grid connection under the corresponding stability analysis method, providing guidance for the safe operation planning and design of actual wind farms. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a flowchart of the method in Example 1;

[0036] Figure 2 This is a schematic diagram of the system structure in Example 1;

[0037] Figure 3 This is a flowchart of the method in Example 2;

[0038] Figure 4 This is a diagram of the wind farm network topology in Example 2;

[0039] Figure 5 This is the power flow diagram of the wind farm in Example 2;

[0040] Figure 6 This is the small-signal equivalent circuit diagram of the collector line in Example 2;

[0041] Figure 7a The amplitude three-dimensional Bode plot in Example 2;

[0042] Figure 7b The three-dimensional Bode plot of the phase in Example 2;

[0043] Figure 8 This is a schematic diagram of the structure of the computer device of the present invention. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0045] Example 1:

[0046] like Figure 1 As shown: A method for binary admittance aggregation modeling of wind farms, comprising the following steps:

[0047] Determine the topology of the turbine layout within the collector lines of the wind farm;

[0048] Based on the topology, construct the corresponding wake model and derive the operating wind speed of each wind turbine under arbitrary natural wind speed.

[0049] The relationship between operating wind speed and grid-connected power is obtained based on Maximum Power Point Tracking (MPPT) control.

[0050] Based on the relationships, a power flow diagram of the wind farm is generated, and the operating points of each unit's grid connection are obtained through power flow calculations.

[0051] List the small-signal voltage admittance matrix of the collector line nodes containing unit operating point information;

[0052] Solve for the voltage admittance matrix to obtain the port admittance aggregation model.

[0053] Based on the binary admittance model of wind turbine generators, this paper derives the grid-connected port admittance model of wind farms according to the topology of the collector lines. The relationship between wind speed and turbine operating point is determined through wake modeling and power flow calculations, achieving the aggregation of the binary admittance model of the wind farm. Compared with the single-unit equivalent aggregation method, this method can accurately characterize the port frequency domain characteristics of the wind farm under the wake effect across the entire wind speed range. When it is necessary to evaluate the small-signal stability of the wind farm grid-connected system across the entire wind speed range, this method can quantitatively determine the relationship between the stable operating wind speed range and wind speed and grid-connected stability under the corresponding stability analysis method, providing guidance for the safe operation planning and design of actual wind farms.

[0054] The relationship between operating wind speed and grid-connected power is obtained based on Maximum Power Point Tracking (MPPT) control. A power flow diagram of the wind farm is constructed based on this relationship, and the operating points of each turbine are obtained through power flow calculations. The small-signal voltage admittance matrix of the collector line nodes, containing turbine operating point information, is constructed. The voltage admittance matrix is ​​solved to obtain the port admittance aggregation model. This method overcomes the drawback of large errors in characterizing the frequency domain impedance characteristics of a single turbine under wake effects. Compared with the traditional one-element impedance model used for qualitative analysis of small-signal stability at discrete wind speed points, the aggregated impedance model can characterize the frequency domain characteristics of the wind farm throughout the entire wind speed operating range and determine the relationship between wind speed and grid-connected stability.

[0055] In this embodiment, the relationship between operating wind speed and grid-connected power is obtained based on Maximum Power Point Tracking (MPPT) control, including:

[0056] P m (v r )=0.5ρπr 2 C p v r 3 ;

[0057] In the formula, P m The wind turbine capture power under MPPT control, ρ is the air density; r is the rotor radius; C p v is the wind energy capture factor. r This refers to wind speed.

[0058] List the small-signal voltage admittance matrix of the collector line nodes containing unit operating point information, including:

[0059] Based on the grid connection point and operating point of each unit, construct the small-signal equivalent circuit diagram;

[0060] Write the node voltage matrix based on the small-signal equivalent circuit diagram;

[0061] Calculate the voltage admittance matrix based on the node voltage matrix.

[0062] The node voltage matrix is ​​as follows:

[0063]

[0064] In the formula, U n (f p ) and I n (f p ) are respectively f p Voltage and current source vectors at the node at the specified frequency; I cn (f c ) is f c Current source vector flowing into the node at a given frequency; Y n (f p Y is the voltage admittance matrix. n (f c ) is f c Voltage node admittance matrix at frequency, U n (f c ) is f c Node voltage vector at a given frequency.

[0065] As a preferred embodiment of the above, the layout topology includes several wind turbines, which are connected to the 35kV bus in a trunk line manner.

[0066] like Figure 2 As shown, this embodiment also includes a wind farm binary admittance aggregation modeling system, using the method described above. The system includes:

[0067] The acquisition unit is used to determine the topology of the arrangement of turbines in the collector lines within a wind farm.

[0068] The derivation unit is used to construct the corresponding wake model based on the topology and derive the operating wind speed of each wind turbine under any natural wind speed.

[0069] The MPPT control unit is used to obtain the relationship between operating wind speed and grid-connected power based on the maximum power point tracking control of the MPPT.

[0070] The power flow calculation unit is used to generate a power flow diagram of the wind farm based on the relationship, and to obtain the operating point of each unit's grid connection point through power flow calculation;

[0071] Admittance matrix unit, used to list the small-signal voltage admittance matrix of the collector line node containing unit operating point information;

[0072] The solver is used to solve the voltage admittance matrix to obtain the port admittance aggregation model.

[0073] Example 2:

[0074] like Figure 3 As shown, this embodiment includes a method for binary admittance aggregation modeling of wind farms, the specific steps of which include:

[0075] S1. Determine the topology of the arrangement of turbine units in the collector lines within the wind farm.

[0076] For example Figure 4 The power collection line structure shown in the figure includes several wind turbines connected to the 35kV bus in a trunk line configuration.

[0077] S2. Construct a suitable wake model based on the arrangement, and derive the operating wind speed of each wind turbine under any natural wind speed.

[0078] S3. The relationship between operating wind speed and grid-connected power is obtained based on the maximum power tracking control of the wind turbine.

[0079] Under certain conditions, the wind turbine capture power P under MPPT control m It can be determined by wind speed v r Represented as:

[0080] P m (v r )=0.5ρπr 2 C p v r 3 ;

[0081] In the above formula, ρ is the air density; r is the wind turbine radius; C p This represents the wind energy capture factor.

[0082] S4. Draw the power flow diagram of the wind farm and obtain the operating points (grid voltage and current) of each unit at the grid connection point through power flow calculation.

[0083] like Figure 5 As shown, where Y l and Y c These are the line admittance and the ground admittance, U g P is the bus voltage. n (v r () represents the grid-connected power of each unit.

[0084] S5. List the small-signal voltage admittance matrix of the collector line nodes containing the unit's operating point information.

[0085] According to Figure 6 The small-signal equivalent circuit diagram is used to illustrate this, where I pi (f p ) represents frequency f p The coupled current source of the wind turbine generator, V pi (f p ) / k represents f p Unit port voltage at frequency k 2 Y sai (f p V represents the converted self-admittance of the wind turbine at the i-th node. pt (f p ), I pt (f p ) are the collector system ports f p Disturbance voltage and current at a given frequency.

[0086] Based on this, the node voltage matrix can be written as follows:

[0087]

[0088] Among them U n (f p ) and I n (f p ) are respectively f p Voltage and current source vectors at the node at the specified frequency; I cn (f c ) is f c Vector of current source flowing into the node at a given frequency. n (f p Y is the nodal admittance matrix. n (f c ) is f c Voltage node admittance matrix at frequency, U n (f c ) is f c Node voltage vector at a given frequency.

[0089] S6. Solve for the nodal admittance matrix to obtain the port admittance aggregation model.

[0090] To verify the accuracy of this aggregation method, such as Figure 7a and Figure 7b As shown, a three-dimensional Bode plot of wind speed-amplitude (phase)-frequency for the admittance model is plotted, and frequency scanning is performed by building a corresponding simulation model for verification. Figure 7a and Figure 7bThe three-dimensional surface is the mathematical analytical model of admittance, and the points on the plane are the frequency sweep verification points. It can be seen that the established model is consistent with the simulation frequency sweep results, which proves the accuracy and correctness of the aggregation method.

[0091] To address the aforementioned issues, this embodiment derives a grid-connected port admittance model for wind farms based on a binary admittance model of wind turbines and the topology of the collector lines. By using a wake model and power flow calculations, the relationship between wind speed and turbine operating point is determined, thus achieving the aggregation of the binary admittance models for wind farms. This aggregation method is applicable to different collector line structures and wake effects, enabling accurate characterization of the frequency domain characteristics of the wind farm across the entire wind speed operating range under wake effects.

[0092] Compared to single-unit equivalent aggregation methods, this method can accurately characterize the port frequency domain characteristics of a wind farm under wake effects across the entire wind speed range. When it is necessary to evaluate the small-signal stability of a wind farm's grid-connected system across the entire wind speed range, this method can quantitatively determine the relationship between the stable operating wind speed range of the wind farm and wind speed and grid connection stability under the corresponding stability analysis method, providing guidance for the safe operation planning and design of actual wind farms.

[0093] Please see Figure 8 The diagram shows a structural schematic of a computer device provided in an embodiment of this application. An embodiment of this application provides a computer device 400, including a processor 410 and a memory 420. The memory 420 stores a computer program executable by the processor 410. When the computer program is executed by the processor 410, it performs the method described above.

[0094] This application embodiment also provides a storage medium 430, on which a computer program is stored, and the computer program is executed by a processor 410 to perform the above method.

[0095] The storage medium 430 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0096] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0097] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0098] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions 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 suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0099] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0100] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0101] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0102] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0103] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for binary admittance aggregation modeling of wind farms, characterized in that, Includes the following steps: Determine the topology of the turbine layout within the collector lines of the wind farm; Based on the topology, a corresponding wake model is constructed, and the operating wind speed of each wind turbine under any natural wind speed is derived based on the wake model. The relationship between the operating wind speed and the grid-connected power is obtained based on maximum power point tracking control; Based on the aforementioned relationships, a power flow diagram of the wind farm is generated, and the operating points of each unit's grid connection are obtained through power flow calculations. List the small-signal voltage admittance matrix of the collector line node containing the operating point information of the unit; Solve for the voltage admittance matrix, and obtain the port admittance aggregation model based on the voltage admittance matrix.

2. The wind farm binary admittance aggregation modeling method according to claim 1, characterized in that, The process of obtaining the relationship between the operating wind speed and the grid-connected power based on maximum power point tracking control includes: P m (v r )=0.5ρπr 2 C p v r 3 ; In the formula, P m The wind turbine capture power under MPPT control, ρ is the air density; r is the rotor radius; C p v is the wind energy capture factor. r This refers to wind speed.

3. The wind farm binary admittance aggregation modeling method according to claim 1, characterized in that, The column listing of the small-signal voltage admittance matrix of the collector line nodes containing the operating point information of the unit includes: Based on the grid connection point and operating point of each unit, construct the small-signal equivalent circuit diagram; Write the node voltage matrix based on the small-signal equivalent circuit diagram; Calculate the voltage admittance matrix based on the node voltage matrix.

4. The wind farm binary admittance aggregation modeling method according to claim 3, characterized in that, The node voltage matrix is ​​as follows: In the formula, U n (f p ) and I n (f p ) are respectively f p Voltage and current source vectors at the node at the specified frequency; I cn (f c ) is f c The vector of current source flowing into the node at a given frequency; Y n (f p Y is the voltage admittance matrix. n (f c ) is f c Voltage node admittance matrix at frequency, U n (f c ) is f c Node voltage vector at a given frequency.

5. The wind farm binary admittance aggregation modeling method according to claim 1, characterized in that, The layout topology includes several wind turbines, which are connected to the 35kV bus in a trunk line manner.

6. A binary admittance aggregation modeling system for wind farms, characterized in that, Using the method as described in any one of claims 1 to 5, the system comprises: The acquisition unit is used to determine the topology of the arrangement of turbines in the collector lines within a wind farm. The derivation unit is used to construct the corresponding wake model based on the topology and derive the operating wind speed of each wind turbine under any natural wind speed. The MPPT control unit is used to obtain the relationship between the operating wind speed and the grid-connected power based on the maximum power point tracking control of the MPPT. The power flow calculation unit is used to generate a power flow diagram of the wind farm based on the aforementioned relationship, and to obtain the operating point of each unit's grid connection point through power flow calculation; Admittance matrix unit, used to list the small-signal voltage admittance matrix of the collector line node containing the operating point information of the unit; The solver unit is used to solve the voltage admittance matrix to obtain the port admittance aggregation model.

7. A computer 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 method as described in any one of claims 1-5.

8. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method as described in any one of claims 1-5.

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