A new energy station unit selection and parameter optimization method, system, device and medium considering small signal stability

Abstract

The present application relates to the technical field of new energy grid-connected system stability analysis, and particularly relates to a new energy station unit selection and parameter optimization method, system, equipment and medium considering small signal stability, comprising obtaining new energy station power grid boundary basic parameters, generating multiple groups of new energy unit alternative schemes according to a preset investment cost constraint; constructing a station binary admittance model for each group of unit alternative schemes, constructing an equivalent double variable open loop transfer function according to the binary admittance model, and quantitatively obtaining a system stability evaluation index; screening low grid-connected oscillation risk unit alternative schemes according to the stability evaluation index, and carrying out full operating interval stability margin checking on the supporting adjustable power grid parameters of the screened unit alternative schemes; in response to the checking result not satisfying the preset stability threshold, iteratively adjusting the adjustable power grid parameters according to the margin distribution law and repeating the checking until the full operating interval stability margin meets the standard; in response to the checking result satisfying the preset stability threshold, then entering the next step.

Description

Technical Field

[0001] This invention relates to the technical field of stability analysis of new energy grid-connected systems, and in particular to a method, system, equipment and medium for selecting and optimizing parameters of new energy power station units that takes into account small signal stability. Background Technology

[0002] With the large-scale grid connection of new energy sources such as wind power and photovoltaics, oscillation problems in the grid-connected systems of new energy power plants are occurring frequently, and small-signal stability has become a key factor restricting the safe operation of new energy power. At present, the industry mainly uses two methods to improve the stability of new energy systems: one is at the system operation level, which involves adding additional damping controllers and other devices to suppress oscillations, but this method has high investment costs and poor overall economic efficiency; the other is at the equipment design level, which involves optimizing the unit control parameters to achieve oscillation suppression, but existing strategies are mostly designed for single or specific operating conditions. The actual operating conditions of new energy power plants change in real time with wind speed and power output, and this type of method is prone to control failure problems.

[0003] Meanwhile, existing research rarely considers the small-signal stability under all operating conditions when selecting generator units and designing system parameters from the early planning and design stage of new energy power plants. Conventional generator selection only considers indicators such as installed capacity, cost, and power generation efficiency, without evaluating grid-connected stability characteristics. This easily leads to problems such as insufficient stability margin and frequent oscillations under all operating conditions after the station is built, resulting in high difficulty and cost for later modifications. Therefore, there is an urgent need to propose a generator unit selection and parameter optimization method that is oriented towards the station design stage and can take into account the small-signal stability under all operating conditions. Summary of the Invention

[0004] This invention provides a method, system, equipment, and medium for selecting and optimizing parameters of new energy power station units that takes into account small signal stability, thereby reducing retrofit costs and operational risks and improving the operational reliability of new energy grid-connected systems. It can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a method for selecting and optimizing parameters of new energy power station units considering small-signal stability, comprising the following steps: Obtain basic parameters of the power grid boundary of new energy power plants, and generate multiple sets of alternative schemes for new energy units based on preset investment cost constraints; For each group of unit alternative schemes, a two-dimensional admittance model of the station is constructed. Based on the two-dimensional admittance model, an equivalent bivariate open-loop transfer function is constructed to quantitatively obtain the system stability evaluation index. Based on the stability evaluation indicators, candidate units with low grid connection oscillation risk are selected, and the stability margin of the adjustable grid parameters of the selected candidate units is checked across the entire operating range. If the verification result does not meet the preset stability threshold, the adjustable power grid parameters are iteratively adjusted according to the margin distribution law and the verification is repeated until the stability margin of the entire operating range meets the standard; if the verification result meets the preset stability threshold, proceed to the next step. The optimal integrated design scheme for the site is output by combining multi-dimensional engineering indicators.

[0006] Furthermore, the steps for generating alternative new energy generating units include: Obtain the basic parameters of the power grid boundary of the new energy power station, and use the basic parameters of the power grid boundary of the new energy power station as fixed boundary conditions; Based on the preset investment cost constraints and combined with the economic indicators of the equipment, the configuration schemes of new energy units are initially screened, and schemes with total investment exceeding the preset investment cost constraints are eliminated, while multiple alternative schemes of new energy units that meet the investment requirements are retained.

[0007] Furthermore, the basic parameters of the power grid boundary include the scale of the power station, the overall layout, the line parameters, and the basic parameters of the transmission channel.

[0008] Furthermore, the method for obtaining the system stability evaluation index specifically includes: For each group of candidate unit schemes, a two-dimensional admittance model for the grid connection side of the power station is constructed; By combining the aforementioned binary admittance model with the grid impedance model containing adjustable parameters, an equivalent bivariate open-loop transfer function is constructed; the two independent variables of the transfer function are the station operating conditions and the adjustable grid parameters, respectively. The system stability evaluation index is calculated based on the bivariate open-loop transfer function. The system stability evaluation index includes the system small-signal stability interval and phase margin. Based on the phase margin calculation results, a set of contour curves corresponding to different phase margins are plotted.

[0009] Furthermore, the expression for the equivalent bivariate open-loop transfer function is: ; In the formula, This represents the open-loop frequency response characteristics of a new energy power station using the i-th type of generator unit under specific operating conditions and specific grid parameters, which is used to determine the small-signal stability of the system. To select the first Equivalent admittance model on the grid-connected side of a wind farm consisting of several wind turbine models; subscript Representation type The wind farm formed by the turbine units; Represents the complex frequency variable of the Laplace transform. , The perturbation frequency; Indicates operating conditions. This represents the grid impedance related to the system's parameters to be determined; This indicates the degree of series compensation or the length of the transmission line.

[0010] Furthermore, the formula for determining the small-signal stable interval of the system is as follows: ; In the formula, This represents the small-signal stable region of the system. Phase margin under different operating conditions and different system parameters; , These represent the lower and upper limits of the system's parameters to be optimized, respectively.

[0011] Furthermore, the expression for calculating the phase margin is as follows: ; In the formula, For amplitude calculation, This is for phase operations.

[0012] Furthermore, the expression for the curve group is: ; In the formula, , , These are the contour curves for phase margins of 0°, 10°, and γ, respectively. The system parameters are corrected based on these contour curves.

[0013] Furthermore, the steps for verifying the stability margin of the adjustable grid parameters for the selected unit alternatives across the entire operating range include: Based on system stability evaluation indicators, set unit selection criteria; The small signal stability interval and phase margin values ​​corresponding to each group of unit candidate schemes are compared with the unit screening criteria one by one. High oscillation risk unit candidate schemes that do not meet the unit screening criteria are eliminated, and low grid connection oscillation risk unit candidate schemes that meet the unit screening criteria are retained. For the selected unit alternatives, the system phase margin under the corresponding operating conditions and parameter combinations is calculated group by group, and the stability margin verification is completed for the entire operating range, in combination with the corresponding adjustable grid parameters.

[0014] This invention also provides a system for selecting and optimizing parameters of new energy power plant units that takes into account small signal stability, including: The alternative scheme generation module obtains the basic parameters of the power grid boundary of the new energy power station and generates multiple sets of alternative schemes for new energy units based on preset investment cost constraints. The stability assessment module constructs a two-dimensional admittance model for each group of unit alternative schemes, and constructs an equivalent bivariate open-loop transfer function based on the two-dimensional admittance model to quantitatively obtain system stability evaluation indicators. The scheme screening and verification module screens candidate schemes for generating units with low grid connection oscillation risk based on the stability evaluation indicators, and performs stability margin verification of the adjustable grid parameters of the selected candidate generating units across the entire operating range. The parameter iteration optimization module, in response to the verification result not meeting the preset stability threshold, iteratively adjusts the adjustable power grid parameters according to the margin distribution law and repeats the verification until the stability margin of the entire operating range meets the standard; in response to the verification result meeting the preset stability threshold, it proceeds to the next step; The solution output module combines multi-dimensional engineering indicators to output the optimal integrated design solution for the site.

[0015] The present invention also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the method for selecting and optimizing parameters of new energy power station units that takes into account small signal stability as described in any of the preceding claims.

[0016] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the method for selecting and optimizing parameters of new energy power station units considering small signal stability as described in any of the preceding claims.

[0017] The technical solution of this invention can achieve the following technical effects: By incorporating small-signal stability analysis into the planning and design phase of renewable energy power plants, grid-connected oscillations are avoided at the source. This approach differs from the traditional post-construction rectification method of adding stabilization devices and optimizing control parameters, thus reducing retrofit costs and operational risks. Based on a binary admittance model and an equivalent bivariate open-loop transfer function, the system's stability range and phase margin under all operating conditions can be accurately quantified. It fully considers the time-varying characteristics of operating conditions such as wind speed and power output, solving the problem of poor applicability of traditional single-condition analysis. The system parameter optimization is guided by phase margin contour curves, with clear parameter adjustment targets and high optimization efficiency. This ensures that renewable energy power plants have sufficient stability margins throughout the entire operating range, improving the operational reliability of renewable energy grid-connected systems. The method is highly versatile and can be applied not only to wind farms but also to the selection and parameter optimization of various renewable energy power plants such as photovoltaic power plants and wind-solar hybrid power plants. Attached Figure Description

[0018] 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.

[0019] Figure 1 This is a schematic diagram of the overall method flow of the present invention; Figure 2 This is a schematic diagram of the topology of a 50MW wind farm; Figure 3 This is a schematic diagram showing the distribution of phase margin with wind speed and series compensation degree; Figure 4 A schematic diagram showing the relationship between the stable wind speed range and the series compensation degree; Figure 5 A comparison of the system oscillation waveforms before and after parameter optimization; Figure 6 The structural diagram of the new energy power station unit selection and parameter optimization system, taking into account small signal stability; Figure 7 This is a schematic diagram of the structure of the computer electronic device in this invention. Detailed Implementation

[0020] 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.

[0021] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] like Figures 1 to 5 The method for selecting and optimizing parameters of new energy power plant units that takes into account small signal stability includes the following steps: S1. Obtain the basic parameters of the power grid boundary of the new energy power plant, and generate multiple sets of alternative schemes for new energy units based on investment cost constraints; the basic parameters of the power grid boundary include the scale of the power plant, the overall layout, the line parameters, and the basic parameters of the transmission channel; S2. Construct a station binary admittance model for each group of unit alternative schemes, construct an equivalent bivariate open-loop transfer function based on the binary admittance model, and quantitatively obtain system stability evaluation indicators. S3. Based on the stability evaluation indicators, select alternative units with low grid connection oscillation risk, and conduct full-operation range stability margin verification on the adjustable grid parameters of the selected alternative units. S4. If the verification result does not meet the preset stability threshold, adjust the adjustable power grid parameters iteratively according to the margin distribution law and repeat the verification until the stability margin of the entire operating range meets the standard; if the verification result meets the preset stability threshold, proceed to the next step. S5. Combine multi-dimensional engineering indicators to output the optimal integrated design scheme for the site.

[0024] In this embodiment, small-signal stability analysis is performed at the planning and design stage of new energy power plants, avoiding grid-connected oscillation problems from the source. This differs from the traditional post-construction rectification method of adding stabilization devices and optimizing control parameters after construction, reducing modification costs and operational risks. Based on the binary admittance model and the equivalent bivariate open-loop transfer function, the system stability range and phase margin under all operating conditions can be accurately quantified, fully considering the time-varying characteristics of operating conditions such as wind speed and power output, solving the problem of poor applicability of traditional single-condition analysis. The system parameter optimization is guided by the phase margin contour curve, with clear parameter adjustment targets and high optimization efficiency, ensuring that new energy power plants have sufficient stability margins throughout the entire operating range, improving the operational reliability of the new energy grid-connected system. The method is highly versatile and can be applied not only to wind farms but also to the unit selection and parameter optimization of various new energy power plants such as photovoltaic power plants and wind-solar hybrid power plants.

[0025] Based on the above embodiments, the basic parameters of the power grid boundary of the new energy power station are obtained. The parameters include the total scale of the power station, the overall layout of the units in the power station, the electrical parameters of the collection lines and the basic parameters of the grid-connected transmission channels. The basic parameters of the power grid boundary of the new energy power station are used as fixed boundary conditions and are applicable to the stability modeling and evaluation process of all subsequent unit schemes. Based on preset investment cost constraints, and combined with economic indicators such as rated capacity of a single unit, cost per unit capacity, and total equipment procurement cost, the configuration schemes of new energy units are initially screened, eliminating schemes whose total investment exceeds the constraints, and retaining multiple alternative schemes of new energy units that meet the investment requirements; each alternative scheme corresponds to a clearly defined unit model, single unit capacity, number of units, and total installed capacity. In this embodiment, the basic parameters of the power grid boundary of the new energy power station are obtained as fixed boundary conditions. The setting of these fixed boundary conditions provides a unified comparison benchmark for the stability quantification results of different alternative schemes in subsequent steps, reducing evaluation deviations caused by inconsistent boundary conditions. Based on the preset investment cost constraints, combined with economic indicators such as the rated capacity of a single unit, the cost per unit capacity, and the total cost of equipment procurement, the new energy unit configuration schemes are initially screened, eliminating schemes whose total investment exceeds the constraint range, and retaining multiple sets of alternative schemes that meet the investment requirements. Each set of alternative schemes corresponds to a specific unit model, single unit capacity, number of units, and total installed capacity. Before entering the stability assessment, this initial screening step reduces the number of candidate schemes by using investment cost constraints as boundary conditions, thereby reducing the number of schemes that need to construct a binary admittance model and open-loop transfer function.

[0026] Based on the above embodiments, a two-dimensional admittance model for the grid-connected side of the wind farm is constructed for each group of candidate wind farm schemes. The two-dimensional admittance model of the wind farm has two independent variables: disturbance frequency and operating condition, corresponding to the equivalent grid-connected admittance characteristics of the wind farm under different wind speeds or output power. The model parameters correspond one-to-one with the model, number of units and layout topology of the selected wind farm. The admittance characteristics under the same candidate scheme change dynamically with the wind farm operating conditions. Then, by combining the aforementioned binary admittance model with the grid impedance model containing adjustable parameters, an equivalent bivariate open-loop transfer function is constructed. The two independent variables of the transfer function are the station operating conditions and the adjustable grid parameters, which can simultaneously characterize the combined impact of unit-side operating condition fluctuations and grid-side parameter adjustments on the open-loop characteristics. The expression of the equivalent bivariate open-loop transfer function is as follows: ; In the formula, This represents the open-loop frequency response characteristics of a new energy power station using the i-th type of generator unit under specific operating conditions and specific grid parameters, which is used to determine the small-signal stability of the system. To select the first The grid-connected equivalent admittance model of a wind farm composed of various wind turbine models is closely related to frequency and operating conditions. (Subscript) Representation type The wind farm formed by the units, Represents the complex frequency variable of the Laplace transform. , For the perturbation frequency, Indicates operating conditions. This represents the grid impedance related to the system's parameters to be determined. Indicates the degree of series compensation or the length of the transmission line; The system stability evaluation index is calculated based on the bivariate open-loop transfer function. The system stability evaluation index includes the system small-signal stability interval and phase margin. The stability interval corresponds to the operating conditions and parameter value ranges that satisfy the stability criterion, and the phase margin corresponds to the system stability margin value under different operating conditions and parameter combinations. The formula for determining the system small-signal stability interval is: ; In the formula, This represents the small-signal stable region of the system. Phase margin under different operating conditions and different system parameters; , These are the lower and upper limits of the values ​​for the system's parameters to be optimized, respectively. The expression for calculating phase margin is: ; In the formula, in the formula, For amplitude calculation, For phase operation; Based on the phase margin calculation results within the adjustable parameters of the power grid, a set of contour curves corresponding to different phase margins is plotted. The expression for the set of curves is as follows: ; In the formula, , , These are the contour curves for phase margins of 0°, 10°, and γ, respectively. The system parameters are corrected based on these contour curves.

[0027] In this embodiment, when constructing the equivalent bivariate open-loop transfer function, the operating conditions and adjustable grid parameters are used as the two independent variables of the transfer function. This allows the transfer function to simultaneously characterize the combined impact of unit-side operating condition fluctuations and grid-side parameter adjustments on the open-loop characteristics. The calculation results of the system stability evaluation index are then linked to factors from both the unit selection and grid parameter dimensions. Based on the bivariate open-loop transfer function, the system's small-signal stability interval and phase margin are calculated. The stability interval corresponds to the operating conditions and parameter value ranges that satisfy the stability criterion, while the phase margin corresponds to the stability margin value under different combinations of operating conditions and parameters. An isoplethora of curves is plotted based on the phase margin calculation results, providing a quantitative basis for system parameter correction in subsequent steps.

[0028] Based on the above embodiments, according to the system stability evaluation index, the unit screening criteria are set, and the screening criteria include two quantitative conditions: the stable interval coverage range and the minimum phase margin. The small signal stability interval and phase margin values ​​corresponding to the candidate schemes of each group of units are compared with the unit screening criteria one by one. High oscillation risk schemes with insufficient stability interval coverage and minimum phase margin below the criterion threshold are eliminated, and low grid connection oscillation risk candidate schemes that meet the criteria are retained. For the selected unit alternatives, and in conjunction with their corresponding adjustable grid parameters, the system phase margin is calculated group by group under the corresponding operating conditions and parameter combinations within the full range of operating conditions and the full range of adjustable grid parameters, thus completing the stability margin verification for the entire operating range. The verification process covers all preset operating condition points and adjustable parameter value points, and verifies whether the phase margin under each combination meets the preset stability threshold.

[0029] In this embodiment, the comparison and screening step uses stability evaluation indicators as the data basis. Before entering the full operating range verification, schemes that do not meet the stability criteria are eliminated, thereby reducing the number of candidate schemes for subsequent full operating range stability margin verification. For the screened candidate schemes, the phase margin under each operating condition and parameter combination is calculated group by group within the full range of operating conditions and the full range of adjustable parameters of the power grid, thus completing the full operating range stability margin verification. The verification process covers all preset operating condition points and adjustable parameter value points, and verifies whether the phase margin under each combination meets the preset stability threshold. The completeness of the verification coverage and the completeness of the adjustable parameter value range ensure that the schemes that finally meet the compliance conditions have verifiable stability margins within the full operating range.

[0030] Based on the above embodiments, the verification result of the stability margin of the entire operating range is obtained. If the phase margin under all operating conditions and adjustable grid parameter combinations is not lower than the preset stability threshold, the verification is deemed to be passed and the subsequent output stage is entered. If the phase margin of any operating condition and adjustable grid parameter combination is lower than the preset stability threshold, the verification is deemed to fail. The margin distribution pattern represented by the phase margin contour curve set is retrieved to locate the operating condition range and corresponding parameter range where the margin is lower than the preset threshold. With the goal of increasing the minimum phase margin across the entire range to above a preset stable threshold, the values ​​of the adjustable power grid parameters are adjusted along the margin increasing direction presented by the contour curve. The adjustable power grid parameters include the line series compensation degree and the transmission line length. After the parameters are adjusted, the equivalent bivariate open-loop transfer function is reconstructed based on the updated adjustable power grid parameters, and the stability margin is checked again for the entire operating range. The process of adjusting parameters and verifying stability margin is repeated until the phase margin for all operating conditions in the entire operating range meets the preset stability threshold, at which point the iteration terminates.

[0031] In this embodiment, by identifying the operating condition range with insufficient margin and the corresponding parameter range, the direction of parameter adjustment is based on a basis, avoiding undirected parameter traversal; the cyclic execution mechanism ensures that the adjustment and verification are repeated in the case of failure to meet the standard, so that the system is re-verified after parameter adjustment to confirm whether the margin meets the standard, until the preset stable threshold is met throughout the entire operating range.

[0032] Based on the above embodiments, a multi-dimensional set of engineering indicators is defined, which includes station cost indicators, operational performance indicators, and operation and maintenance cost indicators. Among them, the cost indicators correspond to the total amount of equipment procurement and the total investment in engineering construction, the operational performance indicators correspond to the unit power generation efficiency and the expected annual power generation, and the operation and maintenance cost indicators correspond to the average annual maintenance cost and maintenance cycle of the equipment. With the stability margin meeting the standard across the entire operating range as a prerequisite constraint, the values ​​of each engineering indicator are calculated one by one for all unit schemes that meet the stability requirements and the corresponding optimized grid parameter combinations. Based on the preset index weighting rules, multiple engineering indicators of each scheme are weighted and calculated to obtain the comprehensive evaluation score of each scheme. Based on the comprehensive evaluation scores, the scheme with the highest score is selected as the optimal integrated design scheme for the station.

[0033] In this embodiment, achieving the stability margin target across the entire operating range is used as a prerequisite constraint. Meeting this target is then used as the entry boundary for weighted ranking of engineering indicators. This ensures that the final output scheme meets the stability margin target across the entire operating range, and then a comprehensive evaluation and ranking of multi-dimensional engineering indicators are performed based on the station cost, operational performance, and maintenance cost indicators. This combination of the prerequisite constraint and the subsequent weighted ranking ensures that the optimal design scheme is generated within the constraint boundary of achieving the stability margin target across the entire operating range. This avoids grid-connected oscillations caused by insufficient stability margin across the entire operating range, and improves the small-signal stability guarantee level of the final output scheme during the grid-connected operation phase.

[0034] like Figure 6 As shown, the present invention also provides a new energy power station unit selection and parameter optimization system that takes into account small signal stability, specifically including the following modules; The alternative scheme generation module obtains the basic parameters of the power grid boundary of the new energy power station and generates multiple sets of alternative schemes for new energy units based on preset investment cost constraints. The stability assessment module constructs a two-dimensional admittance model for each group of unit alternative schemes, and constructs an equivalent bivariate open-loop transfer function based on the two-dimensional admittance model to quantitatively obtain system stability evaluation indicators. The scheme screening and verification module screens candidate schemes for generating units with low grid connection oscillation risk based on the stability evaluation indicators, and performs stability margin verification of the adjustable grid parameters of the selected candidate generating units across the entire operating range. The parameter iteration optimization module, in response to the verification result not meeting the preset stability threshold, iteratively adjusts the adjustable power grid parameters according to the margin distribution law and repeats the verification until the stability margin of the entire operating range meets the standard; in response to the verification result meeting the preset stability threshold, it proceeds to the next step; The solution output module combines multi-dimensional engineering indicators to output the optimal integrated design solution for the site.

[0035] like Figure 7 As shown, the present invention also provides an electronic device, characterized in that it includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the method for selecting and optimizing parameters of new energy power plant units considering small-signal stability as described above, including the following steps: obtaining basic parameters of the power grid boundary of the new energy power plant; generating multiple sets of new energy unit candidate schemes according to preset investment cost constraints; constructing a two-dimensional admittance model for each set of unit candidate schemes; constructing an equivalent bivariate open-loop transfer function according to the two-dimensional admittance model; quantitatively obtaining system stability evaluation indicators; screening low grid-connected oscillation risk unit candidate schemes according to the stability evaluation indicators; performing full-operation range stability margin verification on the matching adjustable power grid parameters of the screened unit candidate schemes; responding to the verification result not meeting the preset stability threshold, iteratively adjusting the adjustable power grid parameters according to the margin distribution law and repeating the verification until the full-operation range stability margin meets the standard; responding to the verification result meeting the preset stability threshold, proceeding to the next step; and outputting the optimal integrated design scheme of the power plant by combining multi-dimensional engineering indicators.

[0036] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the steps of the method for selecting and optimizing parameters of new energy power plant units considering small-signal stability as described above, including the following steps: obtaining basic parameters of the power grid boundary of the new energy power plant; generating multiple sets of new energy unit candidate schemes based on preset investment cost constraints; constructing a two-dimensional admittance model for each set of unit candidate schemes; constructing an equivalent bivariate open-loop transfer function based on the two-dimensional admittance model; quantitatively obtaining system stability evaluation indicators; screening low-grid-connected oscillation risk unit candidate schemes based on the stability evaluation indicators; performing a full-operation-range stability margin check on the adjustable power grid parameters of the screened unit candidate schemes; responding to the check result not meeting the preset stability threshold, iteratively adjusting the adjustable power grid parameters according to the margin distribution law and repeating the check until the full-operation-range stability margin meets the standard; responding to the check result meeting the preset stability threshold, proceeding to the next step; and outputting the optimal integrated design scheme for the power plant by combining multi-dimensional engineering indicators.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 selecting and optimizing parameters of new energy power plant units considering small-signal stability, characterized in that, Includes the following steps: Obtain basic parameters of the power grid boundary of new energy power plants, and generate multiple sets of alternative schemes for new energy units based on preset investment cost constraints; For each group of unit alternative schemes, a two-dimensional admittance model of the station is constructed. Based on the two-dimensional admittance model, an equivalent bivariate open-loop transfer function is constructed to quantitatively obtain the system stability evaluation index. Based on the stability evaluation indicators, candidate units with low grid connection oscillation risk are selected, and the stability margin of the adjustable grid parameters of the selected candidate units is checked across the entire operating range. If the verification result does not meet the preset stability threshold, the adjustable power grid parameters are iteratively adjusted according to the margin distribution law and the verification is repeated until the stability margin of the entire operating range meets the standard; if the verification result meets the preset stability threshold, proceed to the next step. The optimal integrated design scheme for the site is output by combining multi-dimensional engineering indicators.

2. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 1, characterized in that, The steps for generating the alternative new energy generating unit scheme include: Obtain the basic parameters of the power grid boundary of the new energy power station, and use the basic parameters of the power grid boundary of the new energy power station as fixed boundary conditions; Based on the preset investment cost constraints and combined with the economic indicators of the equipment, the configuration schemes of new energy units are initially screened, and schemes with total investment exceeding the preset investment cost constraints are eliminated, while multiple alternative schemes of new energy units that meet the investment requirements are retained.

3. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 2, characterized in that, The basic parameters of the power grid boundary include the scale of the power station, the overall layout, the line parameters, and the basic parameters of the transmission channel.

4. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 2, characterized in that, The method for obtaining the system stability evaluation index specifically includes: For each group of candidate unit schemes, a two-dimensional admittance model for the grid connection side of the power station is constructed; By combining the aforementioned binary admittance model with the grid impedance model containing adjustable parameters, an equivalent bivariate open-loop transfer function is constructed; the two independent variables of the transfer function are the station operating conditions and the adjustable grid parameters, respectively. The system stability evaluation index is calculated based on the bivariate open-loop transfer function. The system stability evaluation index includes the system small-signal stability interval and phase margin. Based on the phase margin calculation results, a set of contour curves corresponding to different phase margins are plotted.

5. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 4, characterized in that, The expression for the equivalent bivariate open-loop transfer function is: ； In the formula, This represents the open-loop frequency response characteristics of a new energy power station using the i-th type of generator unit under specific operating conditions and specific grid parameters, which is used to determine the small-signal stability of the system. To select the first Equivalent admittance model on the grid-connected side of a wind farm consisting of several wind turbine models; subscript Representation type The wind farm formed by the turbine units; Represents the complex frequency variable of the Laplace transform. , The perturbation frequency; Indicates operating conditions. This represents the grid impedance related to the system's parameters to be determined. This indicates the series compensation degree or the length of the transmission line.

6. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 4, characterized in that, The formula for determining the small-signal stable interval of the system is as follows: ； In the formula, This represents the small-signal stable region of the system. Phase margin under different operating conditions and different system parameters; , These represent the lower and upper limits of the system's parameters to be optimized, respectively.

7. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 4, characterized in that, The expression for calculating the phase margin is as follows: ； In the formula, For amplitude calculation, This is for phase operations.

8. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 4, characterized in that, The expression for the curve group is: ； In the formula, , , These are the contour curves for phase margins of 0°, 10°, and γ, respectively. The system parameters are corrected based on these contour curves.

9. The method for selecting and optimizing parameters of new energy power station units considering small-signal stability according to claim 4, characterized in that, The steps for verifying the stability margin of the adjustable grid parameters for the selected unit alternatives across the entire operating range include: Based on system stability evaluation indicators, set unit selection criteria; The small signal stability interval and phase margin values ​​corresponding to each group of unit candidate schemes are compared with the unit screening criteria one by one. High oscillation risk unit candidate schemes that do not meet the unit screening criteria are eliminated, and low grid connection oscillation risk unit candidate schemes that meet the unit screening criteria are retained. For the selected unit alternatives, the system phase margin under the corresponding operating conditions and parameter combinations is calculated group by group, and the stability margin verification is completed for the entire operating range, in combination with the corresponding adjustable grid parameters.

10. A system for selecting and optimizing parameters of new energy power plant units considering small-signal stability, characterized in that, include: The alternative scheme generation module obtains the basic parameters of the power grid boundary of the new energy power station and generates multiple sets of alternative schemes for new energy units based on preset investment cost constraints. The stability assessment module constructs a two-dimensional admittance model for each group of unit alternative schemes, and constructs an equivalent bivariate open-loop transfer function based on the two-dimensional admittance model to quantitatively obtain system stability evaluation indicators. The scheme screening and verification module screens candidate schemes for generating units with low grid connection oscillation risk based on the stability evaluation indicators, and performs stability margin verification of the adjustable grid parameters of the selected candidate generating units across the entire operating range. The parameter iteration optimization module, in response to the verification result not meeting the preset stability threshold, iteratively adjusts the adjustable power grid parameters according to the margin distribution law and repeats the verification until the stability margin of the entire operating range meets the standard; in response to the verification result meeting the preset stability threshold, it proceeds to the next step; The solution output module combines multi-dimensional engineering indicators to output the optimal integrated design solution for the site.

11. An electronic device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the method for selecting and optimizing parameters of new energy power station units that takes into account small signal stability as described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for selecting and optimizing parameters of new energy power station units that takes into account small signal stability as described in any one of claims 1 to 9.

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