Semi-direct drive wind farm equivalent impedance modeling method and device

Abstract

The present application proposes a method for modeling the equivalent impedance of a semi-direct drive wind farm, which relates to the technical field of wind farm modeling in power systems. Among them, the method includes: solving the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance; calculating an optimization coefficient based on the equivalent impedance, where the optimization coefficient includes a real part optimization coefficient and an imaginary part optimization coefficient; and optimizing the equivalent impedance using the optimization coefficient. The present application adopting the above solution can efficiently and quickly obtain the equivalent model of the semi-direct drive wind farm, and the obtained results provide an important basis for the impact analysis of the wind farm connected to the power grid.

Description

Technical Field

[0001] This application relates to the technical field of wind farm modeling in power systems, and particularly to a method and device for modeling the equivalent impedance of a semi-direct drive wind farm. Background Art

[0002] With the successive completion of ten-million-kilowatt-level wind power bases, the large-scale centralized grid connection of wind turbines poses a huge challenge to the safe and stable operation of the power system. Constructing an equivalent model that can accurately describe the overall characteristics of a large-scale wind farm is the basis for studying the operation and control of a high-proportion wind power system. The equivalent of a detailed wind farm model is an important part of wind farm dynamic equivalence. The dynamic equivalent modeling of wind farms has become an important research method for analyzing the grid connection characteristics of large-scale wind farms. At present, the research on the characteristics of a single semi-direct drive wind turbine is very extensive, but there is little introduction to the overall characteristics of the wind farm. Due to the huge differences in the operation of wind turbines, a multi-machine equivalent model can better reflect the dynamic characteristics of the wind farm. Summary of the Invention

[0003] This application aims to at least solve one of the technical problems in the related art to some extent.

[0004] To this end, the first object of this application is to propose a method for modeling the equivalent impedance of a semi-direct drive wind farm, which solves the problem that the existing methods have very extensive research on the characteristics of a single semi-direct drive wind turbine, but little research on the overall characteristics of the wind farm. The wind farm is equivalent to a form of a series connection of an ideal voltage source and an equivalent impedance, and at the same time, a calculation method for the equivalent impedance is proposed, providing an important basis for analyzing the impact of large-scale wind turbines connected to the grid.

[0005] The second object of this application is to propose a device for modeling the equivalent impedance of a semi-direct drive wind farm.

[0006] The third object of this application is to propose a non-transitory computer-readable storage medium.

[0007] To achieve the above object, an embodiment of the first aspect of this application proposes a method for modeling the equivalent impedance of a semi-direct drive wind farm, including: solving the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance; calculating an optimization coefficient according to the equivalent impedance, where the optimization coefficient includes a real part optimization coefficient and an imaginary part optimization coefficient; and optimizing the equivalent impedance using the optimization coefficient.

[0008] Optionally, in an embodiment of this application, the equivalent resistance is expressed as:

[0009]

[0010] where real() represents obtaining the real part, H represents the number of wind farm units, Denote the power factor of the Kth wind turbine, S denote the apparent power output by the wind turbine, V k Denote the extreme voltage amplitude of the Kth unit, θ k Denote the extreme voltage phase of the Kth unit, V pp Denote the bus voltage amplitude, θ pp Denote the bus voltage phase.

[0011] Optionally, in an embodiment of the present application, the equivalent reactance is expressed as:

[0012]

[0013] Wherein, imag() denotes obtaining the imaginary part, H denotes the number of wind turbines in the wind farm, Denote the power factor of the Kth wind turbine, S denote the apparent power output by the wind turbine, V k Denote the extreme voltage amplitude of the Kth unit, θ k Denote the extreme voltage phase of the Kth unit, V pp Denote the bus voltage amplitude, θ pp Denote the bus voltage phase.

[0014] Optionally, in an embodiment of the present application, the real part optimization coefficient is expressed as:

[0015]

[0016] Wherein, real() denotes obtaining the real part, H denotes the number of wind turbines in the wind farm, Denote the power factor of the Kth wind turbine, S denote the apparent power output by the wind turbine, V k Denote the extreme voltage amplitude of the Kth unit, θ k Denote the extreme voltage phase of the Kth unit, V pp Denote the bus voltage amplitude, θ pp Denote the bus voltage phase.

[0017] Optionally, in an embodiment of the present application, the imaginary part optimization coefficient is expressed as:

[0018]

[0019] Wherein, imag() denotes obtaining the imaginary part, H denotes the number of wind turbines in the wind farm, Denote the power factor of the Kth wind turbine, S denote the apparent power output by the wind turbine, V k Denote the extreme voltage amplitude of the Kth unit, θ k Denote the extreme voltage phase of the Kth unit, V pp Denote the bus voltage amplitude, θ pp Denote the bus voltage phase.

[0020] Optionally, in an embodiment of the present application, an optimization coefficient is used to optimize the equivalent impedance, expressed as:

[0021]

[0022] where R eq_OPT represents the optimized resistance, X eq_OPT represents the optimized reactance, R eq represents the equivalent resistance, X eq represents the equivalent reactance, and η R represents the real - part optimization coefficient.

[0023] To achieve the above object, an embodiment of the second aspect of the present application proposes a semi - direct - drive wind farm equivalent impedance modeling device, including: a solving module, a calculating module, and an optimizing module, where

[0024] The solving module is used to solve the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance;

[0025] The calculating module is used to calculate the optimization coefficient, where the optimization coefficient includes a real - part optimization coefficient and an imaginary - part optimization coefficient;

[0026] The optimizing module is used to optimize the equivalent impedance using the optimization coefficient.

[0027] To achieve the above object, an embodiment of the third aspect of the present application proposes a non - transitory computer - readable storage medium, which, when the instructions in the storage medium are executed by a processor, can execute a semi - direct - drive wind farm equivalent impedance modeling method.

[0028] The semi - direct - drive wind farm equivalent impedance modeling method, the semi - direct - drive wind farm equivalent impedance modeling device, and the non - transitory computer - readable storage medium of the embodiments of the present application solve the problem that existing methods have studied the characteristics of a single semi - direct - drive wind turbine very extensively, but have studied the overall characteristics of the wind farm less. By proposing a wind farm dynamic equivalent modeling method based on real - time data, the wind farm is equivalent to a form of a series connection of an ideal voltage source and an equivalent impedance, and at the same time, a calculation method of the equivalent impedance is proposed, providing an important basis for the impact analysis of large - scale wind turbines connected to the power grid.

[0029] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above - mentioned and / or additional aspects and advantages of the present application will become obvious and easy to understand from the following description of the embodiments in conjunction with the drawings, where:

[0031] Figure 1 Flow chart of a semi - direct - drive wind farm equivalent impedance modeling method provided by Embodiment 1 of this application;

[0032] Figure 2 Structural schematic diagram of a semi - direct - drive wind farm equivalent impedance modeling device provided by Embodiment 2 of this application. Detailed implementation manners

[0033] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, but should not be construed as limiting the present application.

[0034] The semi - direct - drive wind farm equivalent impedance modeling method and device of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0035] Figure 1 Flow chart of a semi - direct - drive wind farm equivalent impedance modeling method provided by Embodiment 1 of this application.

[0036] As Figure 1 shown, the semi - direct - drive wind farm equivalent impedance modeling method includes the following steps:

[0037] Step 101: Solve the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance;

[0038] Step 102: Calculate an optimization coefficient according to the equivalent impedance, where the optimization coefficient includes a real - part optimization coefficient and an imaginary - part optimization coefficient;

[0039] Step 103: Optimize the equivalent impedance using the optimization coefficient.

[0040] The semi - direct - drive wind farm equivalent impedance modeling method of the embodiments of the present application solves the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance; calculates an optimization coefficient according to the equivalent impedance, where the optimization coefficient includes a real - part optimization coefficient and an imaginary - part optimization coefficient; and optimizes the equivalent impedance using the optimization coefficient. Thus, it can solve the problem that the existing methods have studied the characteristics of a single semi - direct - drive wind turbine very extensively, but have studied the overall characteristics of the wind farm less. By proposing a wind farm dynamic equivalent modeling method based on real - time data, the wind farm is equivalent to a form of a series connection of an ideal voltage source and an equivalent impedance, and at the same time, a calculation method of the equivalent impedance is proposed, providing an important basis for the impact analysis of large - scale wind turbines connected to the power grid.

[0041] Further, in the embodiments of the present application, the equivalent resistance is expressed as:

[0042]

[0043] Among them, real() represents obtaining the real part, H represents the number of wind farm turbines, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the bus voltage amplitude, θ pp represents the bus voltage phase.

[0044] Furthermore, in the embodiment of the present application, the equivalent reactance is expressed as:

[0045]

[0046] Among them, imag() represents obtaining the imaginary part, H represents the number of wind farm turbines, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the bus voltage amplitude, θ pp represents the bus voltage phase.

[0047] Furthermore, in the embodiment of the present application, the real part optimization coefficient is expressed as:

[0048]

[0049] Among them, real() represents obtaining the real part, H represents the number of wind farm turbines, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the bus voltage amplitude, θ pp represents the bus voltage phase.

[0050] Furthermore, in the embodiment of the present application, the imaginary part optimization coefficient is expressed as:

[0051]

[0052] Among them, imag() represents obtaining the imaginary part, H represents the number of wind farm turbines, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ kDenote the extreme voltage phase of the Kth unit as V pp Denote the amplitude of the collector line voltage as θ pp Denote the phase of the collector line voltage.

[0053] Furthermore, in the embodiment of the present application, an optimization coefficient is used to optimize the equivalent impedance, which is expressed as:

[0054]

[0055] where, R eq_OPT Denote the optimized resistance as X eq_OPT Denote the optimized reactance as R eq Denote the equivalent resistance as X eq Denote the equivalent reactance as η R Denote the real part optimization coefficient.

[0056] Figure 2 It is a schematic structural diagram of a semi-direct drive wind farm equivalent impedance modeling device provided in the second embodiment of the present application.

[0057] As Figure 2 shown, the semi-direct drive wind farm equivalent impedance modeling device includes: a solution module, a calculation module, and an optimization module, where

[0058] The solution module 10 is used to solve the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance;

[0059] The calculation module 20 is used to calculate the optimization coefficient, where the optimization coefficient includes a real part optimization coefficient and an imaginary part optimization coefficient;

[0060] The optimization module 30 is used to optimize the equivalent impedance using the optimization coefficient.

[0061] The semi-direct drive wind farm equivalent impedance modeling device of the embodiment of the present application includes: a solution module, a calculation module, and an optimization module, where the solution module is used to solve the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance; the calculation module is used to calculate the optimization coefficient, where the optimization coefficient includes a real part optimization coefficient and an imaginary part optimization coefficient; the optimization module is used to optimize the equivalent impedance using the optimization coefficient. Thus, it can solve the problem that the existing methods have studied the characteristics of single semi-direct drive wind turbines very extensively, but have studied the overall characteristics of the wind farm less. By proposing a wind farm dynamic equivalent modeling method based on real-time data, the wind farm is equivalent to a form of a series connection of an ideal voltage source and an equivalent impedance, and at the same time, a calculation method for the equivalent impedance is proposed, providing an important basis for the impact analysis of large-scale wind turbines connected to the power grid.

[0062] To implement the above embodiments, the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the equivalent impedance modeling method for a semi-direct drive wind farm in the above embodiments is implemented.

[0063] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. 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, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0064] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0065] Any process or method description in a flowchart or described in other ways herein can be understood as representing a module, segment, or portion of code including one or more executable instructions for implementing a customized logical function or process. The scope of the preferred embodiments of the present application includes additional implementations, where the functions may be executed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0066] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definable sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then stored in a computer memory.

[0067] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having suitable combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), and the like.

[0068] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the method of the above-described embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0069] In addition, each functional unit in various embodiments of the present application may be integrated into one processing module, may exist separately physically for each unit, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0070] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for modeling the equivalent impedance of a semi-direct drive wind farm, characterized in that, it includes the following steps: Solve the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance; Calculate the optimization coefficients according to the equivalent impedance, where the optimization coefficients include a real part optimization coefficient and an imaginary part optimization coefficient; Optimize the equivalent impedance using the optimization coefficients; where the equivalent resistance is expressed as: Among them, real() represents obtaining the real part, H represents the number of wind farm turbines, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the collector line voltage amplitude, θ pp represents the collector line voltage phase; the equivalent reactance is expressed as: Among them, imag() represents obtaining the imaginary part, H represents the number of wind turbines in the wind farm, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the collector line voltage amplitude, θ pp represents the collector line voltage phase; the real part optimization coefficient is expressed as: Among them, real() represents obtaining the real part, H represents the number of wind farm turbines, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the collector line voltage amplitude, θ pp represents the collector line voltage phase; the imaginary part optimization coefficient is expressed as: Among them, imag() represents obtaining the imaginary part, H represents the number of wind turbines in the wind farm, represents the power factor of the Kth wind turbine, S represents the apparent power output by the wind turbine, V k represents the extreme voltage amplitude of the Kth unit, θ k represents the extreme voltage phase of the Kth unit, V pp represents the bus voltage amplitude, θ pp represents the bus voltage phase; the optimizing the equivalent impedance using the optimization coefficients is expressed as: Among them, R eq_OPT represents the optimized resistance, X eq_OPT represents the optimized reactance, R eq represents the equivalent resistance, X eq represents the equivalent reactance, η R represents the real part optimization coefficient.

2. A device for modeling the equivalent impedance of a semi-direct drive wind farm, characterized in that, the device implements the method described in claim 1, and the device includes a solving module, a calculating module, and an optimizing module, where, the solving module is used to solve the equivalent impedance of the wind farm, where the equivalent impedance includes an equivalent resistance and an equivalent reactance; the calculating module is used to calculate the optimization coefficients, where the optimization coefficients include a real part optimization coefficient and an imaginary part optimization coefficient; the optimizing module is used to optimize the equivalent impedance using the optimization coefficients.

3. A non-transitory computer-readable storage medium, on which a computer program is stored, characterized in that, when the computer program is executed by a processor, it implements the method described in claim 1.

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