Method and system for analyzing and calculating internal short-circuit current of wind power plant

Abstract

The embodiment of the invention provides a wind power plant internal short-circuit current analytical calculation method and system, and belongs to the technical field of power system analysis. The method comprises the following steps: acquiring electrical topological data and operation state data of a wind power plant, and constructing a wind power plant equivalent network model based on the electrical topological data; constructing a wind turbine generator short-circuit injection model, and generating a short-circuit analysis model; preset short-circuit working condition parameters are obtained, a short-circuit working condition is applied to the short-circuit analytical model, short-circuit current is solved in an analytical calculation mode, and an initial short-circuit current analytical result is output; and correcting the wind turbine generator short-circuit injection model, performing analytical calculation on the short-circuit analytical model again under the constraint of the corrected wind turbine generator short-circuit injection model, and outputting a target short-circuit current analytical result. According to the method, an injection model correction mechanism based on an initial short-circuit current result is introduced into an analytic calculation framework, so that consistency analytic calculation of short-circuit current distribution and network equivalence relation of different electrical positions in the wind power plant is realized.

Description

Technical Field

[0001] This invention relates to the field of power system analysis technology, specifically to an analytical calculation method and system for short-circuit current inside a wind farm. Background Technology

[0002] With the continuous growth of wind power installed capacity, the proportion of wind farms in the power system is constantly increasing. The short-circuit current characteristics of wind farms under fault conditions have become a key technical issue that needs to be considered in power system planning, relay protection configuration, and equipment selection. Unlike traditional synchronous generators, wind farms typically consist of multiple wind turbines connected to the grid through collector lines. Their internal electrical structure exhibits complex topological characteristics with multiple nodes and branches. Furthermore, wind turbines often use power electronic converters for grid connection, resulting in significant nonlinearity and condition-dependent current response behavior under short-circuit conditions.

[0003] Existing short-circuit current calculation methods are mostly based on traditional power system assumptions, typically using equivalent power source models or unified equivalent impedance models to simplify the power source side. When applied to wind farm scenarios, these methods often neglect the influence of differences in wind turbine operating states, the internal topology of the collector lines, and the distribution of turbine grid connection nodes on the short-circuit current distribution, leading to discrepancies between the calculated results and the actual short-circuit response. Furthermore, some methods rely on electromagnetic transient simulations to analyze the short-circuit process in wind farms. While these methods can reflect certain dynamic characteristics, the calculation process is complex and computationally intensive, making it difficult to meet the requirements of computational efficiency and repeatability in engineering design phases or multi-condition analysis scenarios.

[0004] On the other hand, in the analytical calculation research on short-circuit current of wind farms, existing technologies usually adopt a one-time equivalent processing method in the model construction or calculation process. They lack a closed-loop calculation mechanism that corrects and re-analyzes the equivalent injection model of the unit based on the initial calculation results, making it difficult to ensure the efficiency of analytical calculation while taking into account the consistency of the model and the reliability of the results.

[0005] Therefore, there is an urgent need for an analytical calculation method for short-circuit current in wind farm scenarios. This method should consider the internal electrical topology and unit operating status of the wind farm to achieve analytical solution and self-consistent model correction of the short-circuit current, thereby improving the engineering applicability of the short-circuit current calculation results. Summary of the Invention

[0006] The purpose of this invention is to provide an analytical calculation method and system for short-circuit current inside a wind farm, so as to at least solve the problems of insufficient characterization of internal topology and difficulty in self-correction of equivalent models of units in wind farm applications of existing short-circuit current calculation methods.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for analytical calculation of short-circuit current within a wind farm. The method includes: acquiring electrical topology data and operating status data of the wind farm, and constructing an equivalent network model of the wind farm based on the electrical topology data; constructing a wind turbine short-circuit injection model based on the operating status data, and mapping the wind turbine short-circuit injection model to the equivalent network model to generate a short-circuit analytical model; acquiring preset short-circuit operating condition parameters, and applying short-circuit conditions to the short-circuit analytical model based on the preset short-circuit operating condition parameters, solving for the short-circuit current using analytical calculation, and outputting an initial short-circuit current analytical result; correcting the wind turbine short-circuit injection model based on the initial short-circuit current analytical result, and performing analytical calculation again on the short-circuit analytical model under the constraints of the corrected wind turbine short-circuit injection model, and outputting a target short-circuit current analytical result.

[0008] Optionally, constructing an equivalent network model of the wind farm based on the electrical topology data includes: identifying each electrical node in the wind farm and the connection relationships between nodes based on the electrical topology data, generating a node set consisting of wind turbine grid-connected nodes, collection line nodes, and collection nodes; assigning corresponding node numbers to each node based on the node set and the connection relationships, and establishing a node admittance relationship description based on the node numbers; and constructing a node admittance matrix to characterize the electrical connection characteristics of the wind farm, based on the node admittance relationship description and the corresponding line parameter data and transformer parameter data in the electrical topology data, as the equivalent network model of the wind farm.

[0009] Optionally, based on the node admittance relationship description and the corresponding line parameter data and transformer parameter data in the electrical topology data, a node admittance matrix for characterizing the electrical connection characteristics of the wind farm is constructed, including: based on the node admittance relationship description, determining the node pairs corresponding to each off-diagonal element in the node admittance matrix, and calculating the branch admittance values ​​between each determined node pair according to the line parameter data; based on the transformer parameter data, calculating the equivalent admittance parameters corresponding to each transformer, and mapping the equivalent admittance parameters to the corresponding node positions in the node admittance matrix; based on the branch admittance values ​​and equivalent admittance parameters corresponding to each node, performing a summary calculation on the diagonal elements of the node admittance matrix to form node self-admittance values ​​that satisfy the node current balance relationship; and determining the admittance relationship containing the off-diagonal elements and the diagonal elements as a node admittance matrix for short-circuit analytical calculation.

[0010] Optionally, constructing a wind turbine short-circuit injection model based on the operating status data includes: extracting the voltage state variables and power injection state variables corresponding to each wind turbine grid-connected node based on the operating status data, as the initial state input of the wind turbine short-circuit injection model; determining the equivalent injection form of each wind turbine under short-circuit conditions based on the initial state input, and constructing the corresponding wind turbine short-circuit injection model parameter set; and associating and mapping the wind turbine short-circuit injection model parameter set with each wind turbine grid-connected node to obtain the wind turbine short-circuit injection model.

[0011] Optionally, the wind turbine short-circuit injection model is mapped to the equivalent network model to generate a short-circuit analytical model, including: determining the injection node position of the wind turbine short-circuit injection model in the equivalent network model based on the wind turbine grid-connected node identifier corresponding to the wind turbine short-circuit injection model; introducing each wind turbine short-circuit injection model as a node injection item to the corresponding node position in the equivalent network model to form a unified network representation including node admittance relationship and node injection relationship; and determining the network representation including the node admittance relationship and the node injection relationship as a short-circuit analytical model for short-circuit current analytical calculation.

[0012] Optionally, a preset short-circuit condition parameter is obtained, and a short-circuit condition is applied to the short-circuit analytical model based on the preset short-circuit condition parameter. The short-circuit current is solved using an analytical calculation method, and an initial short-circuit current analytical result is output. This includes: determining the corresponding short-circuit node positions and short-circuit connection relationships in the short-circuit analytical model based on the preset short-circuit condition parameter; introducing short-circuit constraint relationships corresponding to the preset short-circuit condition parameter at the short-circuit node positions to form a short-circuit analytical model after applying the short-circuit condition; under the constraints of the short-circuit analytical model after applying the short-circuit condition, solving the node current relationships in the short-circuit analytical model using an analytical calculation method to obtain the short-circuit current analytical quantity corresponding to each node; and summing the short-circuit current analytical quantities corresponding to each node to determine the initial short-circuit current analytical result.

[0013] Optionally, the wind turbine short-circuit injection model is corrected based on the initial short-circuit current analysis results, including: extracting the short-circuit injection deviation for each wind turbine based on the initial short-circuit current analysis results, wherein the short-circuit injection deviation is used to characterize the degree of deviation between the wind turbine short-circuit injection model and the initial short-circuit current analysis results; correcting the injection parameters in the wind turbine short-circuit injection model based on the short-circuit injection deviation to generate a corrected wind turbine short-circuit injection model; and remapping the corrected wind turbine short-circuit injection model into the iso-network model to update the short-circuit analysis model.

[0014] Optionally, under the constraints of the modified wind turbine short-circuit injection model, the short-circuit analytical model is recalculated to output the target short-circuit current analytical result. This includes: under the constraints of the modified wind turbine short-circuit injection model, based on the preset short-circuit operating parameters, reconstructing the consistency of the node injection relationship and the node admittance relationship in the short-circuit analytical model; after completing the consistency reconstruction of the node injection relationship and the node admittance relationship, performing analytical calculations on the short-circuit analytical model to obtain the short-circuit current analytical quantity reflecting the modified wind turbine short-circuit injection characteristics, which is used as the target short-circuit current analytical result.

[0015] A second aspect of the present invention provides a short-circuit current analysis and calculation system for a wind farm. The system includes: a data acquisition unit for acquiring electrical topology data and operating status data of the wind farm, and constructing an equivalent network model of the wind farm based on the electrical topology data; a model generation unit for constructing a wind turbine short-circuit injection model based on the operating status data, and mapping the wind turbine short-circuit injection model to the equivalent network model to generate a short-circuit analysis model; an analysis unit for acquiring preset short-circuit operating condition parameters, applying short-circuit conditions to the short-circuit analysis model based on the preset short-circuit operating condition parameters, solving for the short-circuit current using analytical calculation, and outputting an initial short-circuit current analysis result; and an output unit for correcting the wind turbine short-circuit injection model based on the initial short-circuit current analysis result, and performing analytical calculation again on the short-circuit analysis model under the constraints of the corrected wind turbine short-circuit injection model, and outputting a target short-circuit current analysis result.

[0016] On the other hand, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described method for analyzing and calculating short-circuit current inside a wind farm.

[0017] Through the above technical solution, this invention unifies the modeling of the internal electrical topology of the wind farm and the operating state of the wind turbine generators during the analytical calculation of short-circuit current in wind farms. It constructs a short-circuit analytical model by mapping the short-circuit injection model to the equivalent network model, enabling the short-circuit current calculation to reflect the electrical characteristics of multiple nodes and branches within the wind farm. After applying preset short-circuit operating parameters, an analytical calculation method is used to initially solve for the short-circuit current, obtaining initial analytical results that match the operating conditions while ensuring computational efficiency. Furthermore, based on the initial short-circuit current analytical results, the wind turbine generator short-circuit injection model is corrected, and the analytical calculation is re-executed under the constraints of the corrected model, achieving a consistent reconstruction between the short-circuit injection characteristics and the network model, thereby obtaining the target short-circuit current analytical result. This technical solution avoids the one-time equivalent approximation of the wind farm's short-circuit behavior, enabling self-consistent model correction within the analytical calculation framework, and improving the stability and engineering applicability of the short-circuit current calculation results under complex wind farm operating conditions.

[0018] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of the steps of an analytical calculation method for short-circuit current inside a wind farm provided by one embodiment of the present invention; Figure 2 This is a detailed flowchart of step S10 of the analytical calculation method for short-circuit current inside a wind farm provided in one embodiment of the present invention. Figure 3 This is a detailed flowchart of step S30 of the analytical calculation method for short-circuit current inside a wind farm provided in one embodiment of the present invention. Figure 4 This is a comparison chart of the short-circuit current analysis results before and after correction as a function of electrical distance, provided by one embodiment of the present invention; Figure 5 This is a system structure diagram of a wind farm internal short-circuit current analytical calculation system provided by one embodiment of the present invention; Figure 6 This is an internal structural diagram of a computer device provided in one embodiment of the present invention. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] like Figure 1 As shown, embodiments of the present invention provide an analytical calculation method for short-circuit current within a wind farm, the method comprising: Step S10: Obtain the electrical topology data and operating status data of the wind farm, and construct an equivalent network model of the wind farm based on the electrical topology data.

[0022] Specifically, by acquiring electrical topology data and operational status data of wind farms, and constructing an equivalent network model of the wind farm based on the electrical topology data, this invention can uniformly represent the internal electrical structure of wind farms at the analytical calculation level. This allows the electrical connections between multiple wind turbines, multiple collector lines, and collection nodes within the wind farm to be accurately depicted in a network form. The constructed equivalent network model of the wind farm is based on the actual topology, avoiding over-simplification of the wind farm as a whole, and is beneficial for reflecting the impact of different grid connection node locations and branch structures on short-circuit current distribution.

[0023] Simultaneously, by using operational status data as the basic input for subsequent model construction and analytical calculations, the equivalent network model possesses electrical background conditions that match actual operating conditions, providing consistent network constraints for subsequent short-circuit injection model mapping and short-circuit condition analysis. Specifically, such as... Figure 2 Step S10 includes the following steps: Step S101: Based on the electrical topology data, identify each electrical node in the wind farm and the connection relationship between the nodes, and generate a node set consisting of wind turbine grid-connected nodes, collection line nodes and collection nodes.

[0024] Specifically, the electrical structure inside the wind farm is analyzed and identified based on the acquired electrical topology data to determine the electrical nodes within the wind farm and the connection relationships between them. The electrical topology data may include information such as the grid connection location of the wind turbines, the routing of the power collection lines, the connection status of switches and circuit breakers, and the connection relationships of the step-up transformers.

[0025] In the specific implementation process, the electrical topology data is analyzed to distinguish different types of electrical equipment and connection points. The grid connection point directly connected to the wind turbine is identified as the wind turbine grid connection node, the intermediate connection point in the collector line used to connect adjacent branches or equipment is identified as the collector line node, and the location connected to the step-up transformer or external power grid is identified as the collection node.

[0026] Furthermore, based on the line connection relationships and switch status information described in the topology data, the electrical connection relationships between each node are determined, forming a set of node association relationships that reflect the actual electrical structure inside the wind farm. After completing the node type identification and connection relationship determination, the wind turbine grid-connected nodes, collector line nodes, and collection nodes are uniformly summarized to generate a node set for subsequent modeling, thereby providing a clear and complete node foundation for the construction of the wind farm equivalent network model.

[0027] Step S102: Based on the node set and the connection relationship, assign a corresponding node number to each node, and establish a node admittance relationship description based on the node number.

[0028] Specifically, each node is assigned a unique node number based on its type and topological location within the node set. This number is used to distinguish and index nodes during subsequent analytical calculations. Node numbers can be assigned sequentially according to the topological hierarchy or connection order of wind turbine grid-connected nodes, collector line nodes, and aggregation nodes, or they can be uniformly assigned according to a preset numbering rule.

[0029] After node numbering is completed, a node admittance relationship description is established based on the connection relationships between nodes and the electrical topology data. The node admittance relationship description characterizes the electrical coupling relationships between nodes, including whether there are direct electrical connections between nodes and the corresponding admittance correlation form. Through the combined description of node numbering and connection relationships, the complex electrical connection structure within the wind farm can be uniformly expressed in the form of node admittance relationships, thus providing a clear data foundation for the subsequent construction of the node admittance matrix. This step transforms the actual electrical topology within the wind farm into a node relationship representation suitable for analytical calculation, ensuring structural consistency and traceability in the subsequent short-circuit current analytical calculation process.

[0030] In one specific implementation, the wind farm includes three wind turbine grid-connected nodes, two collector line nodes, and one collection node. Let the set of nodes be denoted as . in, For wind turbine grid connection nodes, For collector line nodes, For aggregation nodes. The connection relationships between nodes are determined based on electrical topology data, such as nodes... With nodes Directly connected, nodes With nodes Connected, nodes With nodes Connected.

[0031] Based on the above connection relationships, a description of node admittance relationships can be established, where the nodes With nodes The admittance relationship between them can be expressed as in, is the non-diagonal element in the i-th row and j-th column of the node admittance matrix; The equivalent admittance value is given for the branch directly connected to node i and node j; and the corresponding node admittance relationship is determined based on the admittance value of the branch connected to each node, providing a basis for the construction of the subsequent node admittance matrix.

[0032] Step S103: Based on the node admittance relationship description and the corresponding line parameter data and transformer parameter data in the electrical topology data, construct a node admittance matrix to characterize the electrical connection characteristics of the wind farm, as an equivalent network model of the wind farm.

[0033] Specifically, based on the node admittance relationship description, the node pairs corresponding to each off-diagonal element in the node admittance matrix are determined, and the branch admittance values ​​between each node pair are calculated based on the line parameter data; based on the transformer parameter data, the equivalent admittance parameters corresponding to each transformer are calculated, and the equivalent admittance parameters are mapped to the corresponding node positions in the node admittance matrix; based on the branch admittance values ​​and equivalent admittance parameters corresponding to each node, a summary calculation is performed on the diagonal elements of the node admittance matrix to form node self-admittance values ​​that satisfy the node current balance relationship; the admittance relationship containing the off-diagonal elements and the diagonal elements is determined as the node admittance matrix for short-circuit analytical calculation.

[0034] In this embodiment of the invention, the node pair relationship corresponding to each off-diagonal element in the node admittance matrix is ​​determined based on the node admittance relationship description. For node pairs with direct electrical connections in the topology, the equivalent admittance value of the corresponding branch is calculated based on the line parameter data, and the branch admittance value is filled into the off-diagonal position in the node admittance matrix corresponding to the node pair; for node pairs without direct connections, their corresponding off-diagonal elements remain at zero.

[0035] Furthermore, for the transformer equipment involved in the electrical topology data, the corresponding equivalent admittance parameters are calculated based on the transformer parameter data. The transformer parameter data may include information such as the transformer's rated capacity, short-circuit impedance, and wiring configuration. Through equivalent processing, the electrical characteristics of the transformer are converted into an admittance form compatible with the node admittance matrix. The calculated equivalent admittance parameters are mapped to the corresponding node positions in the node admittance matrix according to the transformer's connection location in the topology, reflecting the transformer's impact on the electrical connection characteristics between nodes.

[0036] After determining the off-diagonal elements and the equivalent admittance parameters of the transformer, a summary calculation is performed on the diagonal elements of the node admittance matrix. Specifically, for any node, its corresponding diagonal element is formed by summing the admittance values ​​of all branches connected to that node and the equivalent admittance parameters mapped to that node, to satisfy the node current balance relationship. Through the above processing, each row and each column in the node admittance matrix can fully reflect the electrical coupling relationship between nodes. Finally, the matrix containing the off-diagonal elements and the admittance relationship of the diagonal elements is determined as the node admittance matrix for short-circuit analytical calculation, and participates in the subsequent short-circuit current analytical calculation process as the equivalent network model of the wind farm.

[0037] In one specific implementation, let the set of wind farm nodes be... in, For wind turbine grid connection nodes, For collector line nodes, For aggregation nodes. Based on electrical topology data, nodes With nodes They are connected by a collector line, and its branch admittance is denoted as ,node With nodes They are connected by a collector line, and its branch admittance is denoted as .node With nodes They are connected by a step-up transformer, and their equivalent admittance is denoted as... .

[0038] The nodal admittance matrix can then be expressed as The diagonal elements are calculated by summing the admittances of each branch connected to the corresponding node and the equivalent admittance of the transformer, thus forming a node admittance matrix that satisfies the node current balance relationship, which is used for subsequent analytical calculation of short-circuit current.

[0039] In this embodiment of the invention, the connection between the wind farm and the external power grid is achieved through a step-up transformer at the collection node. To ensure the solvability of the node admittance matrix in the analytical solution process, the upper-level power grid is equivalent to either the Thevenin power model or the Norton power model in the equivalent network model.

[0040] Specifically, in one embodiment, the external power grid is equivalent to a source with an equivalent voltage. With equivalent impedance The Thevenin model is used, and the data is mapped to the wind farm collection node via a step-up transformer; in another implementation, the external power grid is equivalent to an equivalent current source. With equivalent admittance The Norton model is used, and the equivalent injection term at the collection node is introduced into the node admittance relation. Through the above equivalent processing, the constructed node admittance matrix has a unique solution in the analytical solution process, thereby ensuring the mathematical feasibility of analytical calculation of node voltage and short-circuit current.

[0041] Step S20: Construct a wind turbine short-circuit injection model based on the operating status data, and map the wind turbine short-circuit injection model to the equivalent network model to generate a short-circuit analytical model.

[0042] Specifically, based on the operating status data, the voltage state variables and power injection state variables corresponding to each wind turbine grid-connected node are extracted as the initial state inputs for the wind turbine short-circuit injection model; based on the initial state inputs, the equivalent injection form of each wind turbine under short-circuit conditions is determined, and the corresponding wind turbine short-circuit injection model parameter set is constructed; the wind turbine short-circuit injection model parameter set is associated and mapped with each wind turbine grid-connected node to obtain the wind turbine short-circuit injection model.

[0043] Furthermore, the wind turbine short-circuit injection model is mapped to the equivalent network model to generate a short-circuit analytical model, including: determining the injection node position of the wind turbine short-circuit injection model in the equivalent network model based on the wind turbine grid-connected node identifier corresponding to the wind turbine short-circuit injection model; introducing each wind turbine short-circuit injection model as a node injection term into the corresponding node position in the equivalent network model to form a unified network representation including node admittance relationship and node injection relationship; and determining the network representation including the node admittance relationship and the node injection relationship as the short-circuit analytical model for short-circuit current analytical calculation.

[0044] In this embodiment of the invention, a short-circuit injection model for wind turbines is constructed based on operational status data, and this model is mapped onto an equivalent network model to generate a short-circuit analytical model for subsequent analytical calculations. The operational status data reflects the steady-state operating characteristics of the wind turbine before a short circuit occurs, and may include voltage amplitude, voltage phase angle, and active and reactive power injection information at the wind turbine's grid connection node. By introducing operational status data, the construction of the short-circuit injection model is not dependent on fixed assumptions, but rather remains consistent with the actual operating conditions of the wind turbine.

[0045] In the specific implementation process, firstly, based on the operating status data, the voltage state variables and power injection state variables corresponding to each wind turbine grid-connected node are extracted as the initial state inputs for the wind turbine short-circuit injection model. For any wind turbine grid-connected node... Its steady-state operation can be expressed as: in, This indicates the voltage amplitude at the grid connection node. This indicates the voltage phase angle at the grid connection node. This represents the active power injected into the power grid by the wind turbine. This represents the reactive power injected into the grid by the wind turbine. These state variables collectively characterize the steady-state operating conditions of the wind turbine before a short circuit occurs.

[0046] After obtaining the initial state input, the equivalent injection form of the wind turbine under short-circuit conditions is determined based on the initial state input, and the corresponding wind turbine short-circuit injection model parameter set is constructed. In this embodiment, the wind turbine under short-circuit conditions can be equivalently represented by an injection model jointly described by current injection terms and equivalent impedance terms, and its equivalent injection relationship can be expressed as: in, This represents the equivalent injected current of the wind turbine under short-circuit conditions. This represents the initial injection current determined by the steady-state operating condition. This represents the equivalent admittance parameter corresponding to the wind turbine. This indicates the grid-connected node voltage under short-circuit conditions. This represents the grid-connected node voltage under steady-state operation. Through the above relationship, the current response of the wind turbine during a short circuit can be linked to its steady-state operation, thus forming a set of short-circuit injection model parameters related to the operating conditions.

[0047] Furthermore, the parameter set of the wind turbine short-circuit injection model is associated and mapped with each wind turbine grid-connected node to obtain a complete wind turbine short-circuit injection model. This mapping process is used to clarify the role of each set of injection model parameters in the equivalent network model, enabling the wind turbine short-circuit injection characteristics to participate in network analytical calculations in the form of node injection.

[0048] In a further step, the wind turbine short-circuit injection model is mapped to an equivalent network model to generate a short-circuit analytical model. Specifically, based on the grid-connected node identifiers corresponding to the wind turbine short-circuit injection models, the injection node positions of each wind turbine short-circuit injection model in the equivalent network model are determined, and each injection model is introduced as a node injection term into the network structure described by the node admittance matrix. At this point, the short-circuit analytical model of the wind farm can be uniformly represented as: in, This represents an equivalent network model composed of node admittance matrices. This represents the voltage vector at each node. This represents the nodal injection current vector formed by the short-circuit injection model of each wind turbine. This represents the short-circuit equivalent injection term introduced by the short-circuit condition. This unified expression achieves the coupling of nodal admittance relations and nodal injection relations within the same analytical framework.

[0049] In the short-circuit analytical model, the node injected current vector can be further expressed as a superposition of the injection contributions from each wind turbine, i.e.: in, This represents a collection of wind turbine units. Indicates the first A mapping matrix that maps the injected current of each wind turbine to the entire network node space is used to describe the positional relationship of the grid-connected nodes of the wind turbines in the overall network. This represents the injected current vector generated by the k-th wind turbine under short-circuit conditions. This mapping method enables the superposition and coupling of short-circuit injection models from multiple wind turbines within a unified network model.

[0050] Through the above processing, the resulting short-circuit analytical model structurally incorporates both nodal admittance and nodal injection relationships, and can solve for the short-circuit current response analytically after applying short-circuit operating parameters. This model not only reflects the internal electrical topology of the wind farm but also preserves the influence of the wind turbine operating state on short-circuit injection behavior, providing a unified computational basis for subsequent initial analytical calculations of the short-circuit current and model corrections based on the analytical results.

[0051] In another possible implementation, the wind turbine short-circuit injection model is not determined all at once at the moment of the short circuit, but rather an adaptive injection modeling method based on the sensitivity of the operating state disturbance is introduced.

[0052] Specifically, when constructing the short-circuit injection model for wind turbines, in addition to using steady-state operating data as the initial state input, the model also extracts minute fluctuation characteristics of voltage and power injection at the grid-connected nodes of the wind turbines based on historical operating data or operating data from adjacent time slices. Based on this, sensitivity parameters reflecting the impact of operating state disturbances on injection characteristics are constructed. During the short-circuit analytical calculation, these sensitivity parameters, along with short-circuit condition parameters, participate in the construction of the equivalent injection relationship in the short-circuit injection model, enabling the equivalent injection characteristics of the wind turbines under short-circuit conditions to be dynamically adjusted according to changes in operating state. In this way, the dependence of the wind turbine's short-circuit response on operating state disturbances can be characterized without introducing a transient simulation model, thereby improving the applicability and consistency of the analytical calculation model under complex operating conditions.

[0053] Step S30: Obtain preset short-circuit operating condition parameters, apply short-circuit operating conditions to the short-circuit analytical model based on the preset short-circuit operating condition parameters, solve the short-circuit current using analytical calculation method, and output the initial short-circuit current analytical result.

[0054] Specifically, by acquiring preset short-circuit condition parameters and applying them to the short-circuit analytical model, this invention can model and calculate wind farm short-circuit conditions within a unified analytical framework. The short-circuit condition parameters are used to clarify the short-circuit location, short-circuit type, and corresponding electrical constraints, ensuring clear boundary conditions for the short-circuit analytical model during calculation. After applying the short-circuit condition, the analytical model is solved using analytical methods, obtaining initial analytical results of the short-circuit current without relying on electromagnetic transient simulation. These analytical results, while maintaining computational efficiency, reflect the short-circuit current distribution characteristics under the combined influence of the wind farm's internal electrical topology and the wind turbine's operating state, providing a reliable initial reference for subsequent model correction and consistency reconstruction based on the analytical results. Specifically, such as... Figure 3 Step S30 specifically includes: Step S301: Based on the preset short-circuit operating condition parameters, determine the corresponding short-circuit node positions and short-circuit connection relationships in the short-circuit analytical model.

[0055] Specifically, based on preset short-circuit condition parameters, the locations of short-circuit nodes and short-circuit connections in the short-circuit analytical model are determined. These preset short-circuit condition parameters describe the short-circuit scenario to be analyzed and may include information such as the location of the short circuit, the type of short circuit, and the identifiers of the involved nodes or branches.

[0056] In the specific implementation process, according to the location description in the preset short-circuit condition parameters, the target node that matches the short-circuit condition is located in the node set corresponding to the short-circuit analysis model and determined as the short-circuit node location.

[0057] Furthermore, by combining the short-circuit type parameters, the short-circuit connection relationship that should be established between the short-circuit node and its adjacent nodes is clarified. For example, it is determined whether the short circuit occurs at the node, in the branch, or on the transformer side, and the node pairs or sets of nodes that need to be subject to short-circuit constraints are determined accordingly.

[0058] This step clarifies the role and connection relationships of short-circuit conditions in the short-circuit analytical model without altering the original network structure, providing a clear basis for the subsequent introduction and analytical calculation of short-circuit constraints.

[0059] Step S302: Introduce short-circuit constraint relationships corresponding to the preset short-circuit operating condition parameters at the short-circuit node location to form a short-circuit analytical model after applying the short-circuit operating condition.

[0060] Specifically, based on the determined short-circuit node locations and short-circuit connection relationships, short-circuit constraint relationships corresponding to the preset short-circuit operating condition parameters are introduced at the short-circuit node locations, thereby forming a short-circuit analytical model after applying the short-circuit operating condition. These short-circuit constraint relationships are used to constrain the electrical state at the short-circuit occurrence location without changing the original equivalent network structure, enabling the short-circuit operating condition to be analytically integrated into the short-circuit analytical model.

[0061] In the specific implementation process, based on the short-circuit type and short-circuit impedance characteristics described in the preset short-circuit condition parameters, a short-circuit constraint relationship matching the short-circuit condition is introduced at the short-circuit node location so as to apply the short-circuit condition to the short-circuit analytical model in analytical form.

[0062] When the short-circuit condition is a node-to-ground short circuit, the electrical state of the node is constrained by introducing an equivalent short-circuit admittance between the corresponding short-circuit node and the reference ground. The node-to-ground short-circuit constraint is achieved by equivalent parallel correction of the diagonal elements of the corresponding node in the node admittance matrix to reflect the electrical characteristics of the node-to-ground short-circuit path.

[0063] When the short-circuit condition is a branch short circuit or a short circuit between two nodes, the node connection constraint is established by introducing an equivalent short-circuit branch admittance between the nodes at both ends of the short-circuit branch. Let the two nodes where the short circuit occurs be numbered node a and node b, respectively. The equivalent short-circuit branch admittance is determined by preset short-circuit impedance parameters. During the node admittance matrix mapping process, the diagonal elements corresponding to nodes a and b are updated simultaneously, and an off-diagonal coupling term corresponding to the equivalent short-circuit branch admittance is introduced to equivalently characterize the short-circuit path between nodes a and b without changing the connection relationships of the remaining nodes.

[0064] In another equivalent implementation, the short-circuit constraint relationship can also be achieved by introducing a Norton injection term equivalent to the short-circuit admittance, and the analytical result is equivalent to the above method.

[0065] Step S303: Under the constraints of the short-circuit analytical model after applying the short-circuit condition, the node current relationship in the short-circuit analytical model is solved by analytical calculation to obtain the analytical value of the short-circuit current corresponding to each node.

[0066] Specifically, under the constraints of the short-circuit analytical model after applying the short-circuit condition, the node current relationships in the short-circuit analytical model are solved analytically to obtain the analytical short-circuit current for each node. In the specific implementation, firstly, under the condition of applied short-circuit constraints, an analytical relationship between node voltage and node current is established based on the node admittance matrix and node injection relationship. At this point, the short-circuit analytical model simultaneously includes the node admittance relationship, the wind turbine short-circuit injection relationship, and the constraint terms introduced by the short-circuit condition, which can fully characterize the network electrical characteristics under short-circuit conditions.

[0067] In the analytical calculation process, the short-circuit analytical model is uniformly represented as a linear relationship between the node voltage vector and the node current vector. The node current is obtained by analytically solving for the node voltage. In one specific implementation, the analytical expression for the node voltage can be constructed first based on the model form after applying the short-circuit condition. in, This represents the nodal admittance matrix after applying a short-circuit condition. This represents the nodal injection current vector formed by the wind turbine short-circuit injection model. This represents the equivalent short-circuit injection term introduced by the short-circuit constraint relation. Let represent the node voltage vector to be solved. Using the above analytical relationship, the node voltage distribution under short-circuit conditions can be directly solved without introducing a time step and an iterative convergence criterion.

[0068] After obtaining the analytical results of the node voltages, the analytical values ​​of the node currents corresponding to each node are further calculated based on the node admittance relationship. For any node... Its short-circuit current analysis can be determined by the relationship between the node admittance matrix and the node voltage. in, Represents a node The corresponding short-circuit current analysis value. Represents the nodes in the nodal admittance matrix With nodes Admittance elements between and These represent the analytical voltage values ​​for the corresponding nodes. This indicates that the short-circuit injection model of the wind turbine is at the node. The injected current component introduced at the point. Through this analytical relationship, the analytical results of node voltage can be converted into the analytical quantities of short-circuit current at each node.

[0069] After calculating the analytical values ​​of the short-circuit current at each node, these values ​​are summarized and output in order of node number to form analytical results of the short-circuit current, which characterize the response to short-circuit conditions within the wind farm. Through the above analytical calculation process, this invention achieves direct analytical solution of the short-circuit current while maintaining a clear model structure and traceability of the calculation process.

[0070] Step S304: Summarize the short-circuit current analysis values ​​corresponding to each node to determine the initial short-circuit current analysis result.

[0071] Specifically, after obtaining the short-circuit current analysis values ​​for each node, these values ​​are aggregated according to node numbering order, and the current analysis results of each node under short-circuit conditions are uniformly compiled into initial short-circuit current analysis results. This aggregation process is used to form a result set reflecting the overall short-circuit current distribution characteristics of the wind farm, enabling the short-circuit current responses of different grid-connected nodes, collector line nodes, and collection nodes to be compared and analyzed within the same result framework.

[0072] Step S40: Based on the initial short-circuit current analysis results, correct the wind turbine short-circuit injection model, and under the constraints of the corrected wind turbine short-circuit injection model, perform analytical calculations on the short-circuit analysis model again, and output the target short-circuit current analysis results.

[0073] Specifically, correcting the wind turbine short-circuit injection model based on the initial short-circuit current analysis results includes: extracting the short-circuit injection deviation for each wind turbine based on the initial short-circuit current analysis results, wherein the short-circuit injection deviation is used to characterize the degree of deviation between the wind turbine short-circuit injection model and the initial short-circuit current analysis results; correcting the injection parameters in the wind turbine short-circuit injection model based on the short-circuit injection deviation to generate a corrected wind turbine short-circuit injection model; and remapping the corrected wind turbine short-circuit injection model into the iso-network model to update the short-circuit analysis model.

[0074] Furthermore, under the constraints of the modified wind turbine short-circuit injection model, the short-circuit analytical model is recalculated to output the target short-circuit current analytical result. This includes: under the constraints of the modified wind turbine short-circuit injection model, based on the preset short-circuit operating parameters, reconstructing the consistency of the node injection relationship and node admittance relationship in the short-circuit analytical model; after completing the consistency reconstruction of the node injection relationship and node admittance relationship, performing analytical calculations on the short-circuit analytical model to obtain the short-circuit current analytical quantity reflecting the modified wind turbine short-circuit injection characteristics, which is used as the target short-circuit current analytical result.

[0075] In this embodiment of the invention, after obtaining the initial short-circuit current analysis result, the result is not directly used as the final output. Instead, a model correction process based on the analysis result is further introduced to self-consistently adjust the wind turbine short-circuit injection model, thereby improving the matching degree between the short-circuit analysis model and the actual short-circuit response characteristics. This process analyzes the initial short-circuit current analysis result, identifies the deviation relationship between the wind turbine short-circuit injection model and the analysis result, and corrects the injection model parameters accordingly to form a corrected wind turbine short-circuit injection model.

[0076] In the specific implementation process, based on the initial short-circuit current analysis results, the corresponding short-circuit injection deviation is extracted for each wind turbine. The short-circuit injection deviation is used to characterize the degree of difference between the injection behavior described by the wind turbine short-circuit injection model and the short-circuit analysis results under the current short-circuit condition. For any wind turbine... Its short-circuit injection deviation can be constructed as follows: in, This indicates that in the initial short-circuit current analytical results, compared with the first... The analytical injection current vector corresponding to each grid-connected node of a wind turbine. This represents the model injection current vector given by the wind turbine short-circuit injection model under the same operating conditions. This represents the corresponding short-circuit injection deviation. This deviation can be used to quantitatively characterize the direction and degree of deviation between the model description and the analytical results.

[0077] After obtaining the short-circuit injection deviation, the injection parameters in the wind turbine short-circuit injection model are corrected based on the deviation. In one specific embodiment, the correction of the injection parameters can be achieved by introducing a parameter correction matrix, the correction relationship of which can be expressed as: in, Indicates the first The original parameter vector of a short-circuit injection model for a wind turbine unit. This represents the corrected injection model parameter vector. This represents a parameter correction coefficient matrix related to wind turbine characteristics, used to describe the weight of the impact of short-circuit injection deviation on model parameter correction. This method enables analytical correction of wind turbine short-circuit injection model parameters without introducing an additional control model.

[0078] The correction process for the wind turbine short-circuit injection model is subject to preset physical constraints, including but not limited to: 1) Injection current amplitude constraint, used to limit the short-circuit injection current of wind turbine to not exceed the preset maximum value.

[0079] 2) Injection current component constraint, used to limit the correspondence between reactive current and voltage deviation.

[0080] 3) Parameter correction step size constraint, used to avoid over-adjustment of injected parameters during a single correction process.

[0081] Furthermore, the modified wind turbine short-circuit injection model is remapped into the equivalent network model to update the short-circuit analytical model. This mapping process replaces the node injection relationships in the original short-circuit analytical model with the modified injection parameters, thus keeping the short-circuit analytical model structurally unchanged while maintaining consistency with the initial analytical results in injection characteristics.

[0082] After the short-circuit injection model is corrected, the short-circuit analytical model is recalculated under the constraints of the corrected wind turbine short-circuit injection model to output the analytical result of the target short-circuit current. In this process, the initial analytical steps are not simply repeated; instead, based on the corrected injection relationship, the node injection relationship and node admittance relationship in the short-circuit analytical model are reconstructed for consistency. This consistency reconstruction is achieved by introducing a consistency reconstruction term ΔY. ΔY has a preset structure and only acts on the node admittance elements corresponding to specific nodes or branches, used to characterize the analytical correction of equivalent impedance or equivalent parameters of the external power grid. Specifically, ΔY is limited to not changing the original node connection relationship, but only compensating for the preset diagonal elements in the node admittance matrix or the equivalent admittance terms corresponding to the pooling nodes, thereby achieving analytical consistency between the corrected node injection relationship and node admittance relationship while maintaining the network topology unchanged.

[0083] The consistency reconstruction is used to coordinate the analytical matching between the network coupling characteristics described by the node admittance relationship and the modified node injection relationship, thereby avoiding new analytical inconsistencies introduced by model modification.

[0084] Specifically, the equivalent current constraints at the collection node are constructed based on the equivalent model of the external power grid. When the Norton equivalent model is used for the external power grid, the equivalent injected current at the collection node satisfies the following relationship: in, The voltage resolution value for the collection node. and These are the equivalent admittance parameters and equivalent current source parameters of the external power grid at the collection node, respectively. When the external power grid adopts the Thevenin equivalent model, it is first equivalently transformed into the Norton model before the corresponding parameters are determined.

[0085] After completing the short-circuit injection model correction for the wind turbine and performing a short-circuit analytical calculation, the actual network injection current at the collection node can be obtained from the network side. Based on this, the boundary current inconsistency at the collection node is constructed: The boundary current inconsistency is used to characterize the deviation between the short-circuit analytical results and the equivalent boundary conditions of the external power grid. To eliminate this deviation, without introducing new node or branch connection relationships, the consistency reconstruction term ΔY is limited to the admittance compensation term acting only on the equivalent branch to ground of the collecting node. Make it satisfy the following relationship: This leads to the calculation expression for the consistency refactoring term: in, This is a preset minimum voltage threshold used to avoid numerical instability caused by excessively low node voltage under severe short-circuit conditions.

[0086] During the node admittance matrix mapping process, the consistency reconstruction term ΔY is only used to correct the diagonal elements corresponding to the pooling nodes, and its update rule is as follows: The remaining off-diagonal elements remain unchanged, thus ensuring that the consistency reconstruction process does not alter the original network's node connections and topology, only compensating for the equivalent boundary conditions at the pooling nodes. This method achieves boundary consistency constraints for the short-circuit analytical model under equivalent external power grid conditions.

[0087] In one specific implementation, the short-circuit analytical model after consistency reconstruction can be expressed as: in, Represents the original nodal admittance matrix. This represents the equivalent adjustment term introduced by the consistency reconstruction process, used to characterize the compensatory impact on the network parsing structure after the node injection relationship correction. This represents the node voltage vector obtained under the condition of consistent reconstruction. This represents the nodal injection current vector formed by the modified wind turbine short-circuit injection model. This represents the equivalent short-circuit injection term corresponding to the short-circuit condition.

[0088] After completing the consistency reconstruction, analytical calculations are performed on the short-circuit analytical model to obtain the short-circuit current analytical quantity reflecting the short-circuit injection characteristics of the corrected wind turbine, and this analytical quantity is determined as the target short-circuit current analytical result. Through the above process, this invention realizes model correction and re-analysis based on the initial analytical results within the analytical calculation framework, enabling the short-circuit current calculation results to maintain analytical calculation efficiency while possessing higher model consistency and engineering applicability.

[0089] In another possible implementation, the correction process of the wind turbine short-circuit injection model is not based solely on the initial short-circuit current analysis results under a single short-circuit condition, but rather introduces a joint correction mechanism based on consistency constraints across multiple short-circuit conditions. Specifically, during model correction, multiple preset short-circuit condition parameter sets are constructed for the same wind farm, and corresponding initial short-circuit current analysis results are obtained for each. Subsequently, the short-circuit current analysis results obtained under different short-circuit conditions are used as joint constraints to comprehensively correct the injection parameters of the wind turbine short-circuit injection model, ensuring that the corrected injection model maintains analytical consistency across multiple short-circuit conditions.

[0090] In this implementation, the short-circuit injection deviation no longer reflects only the deviation between the model and the analytical results under a single operating condition. Instead, it forms a comprehensive deviation description by weighted fusion of deviations from multiple operating conditions, thereby avoiding over-correction of model parameters under specific short-circuit conditions. Through this joint correction method, the wind turbine short-circuit injection model can maintain a relatively stable injection characteristic expression when facing different short-circuit locations or different short-circuit types.

[0091] After completing the joint correction, the corrected wind turbine short-circuit injection model is remapped into the equivalent network model, and analytical calculations are performed on the short-circuit analytical model under unified correction model constraints to obtain the target short-circuit current analytical result. This implementation method does not require the introduction of time-domain simulation or control models; it achieves model correction only through consistency constraints between analytical results. This can improve the reliability and generalization ability of the short-circuit current analytical results in multi-condition analysis scenarios while maintaining analytical calculation efficiency.

[0092] In one specific implementation, the method of the present invention is applied to a short-circuit current analysis scenario of a centralized onshore wind farm. This wind farm employs a 35kV collection system, with multiple collection lines converging at the 35kV busbar of the substation and then connected to the upper-level power grid after being stepped up by the main transformer. Each collection line has multiple wind turbine grid-connected nodes, and the electrical distances from different grid-connected nodes to the substation busbar vary.

[0093] In this embodiment, a grid-connected node located in the middle of one of the collector lines is selected as the short-circuit analysis node, and the condition is set as a three-phase short circuit. Before the short circuit occurs, the operating status data of the wind farm is acquired through the monitoring system, including the voltage level at each grid-connected node and the active and reactive power output of the wind turbine generators. Based on the operating status data and the wind farm electrical topology data, an equivalent network model of the wind farm is constructed, and a short-circuit injection model of the wind turbine generators is further established. Initial short-circuit current analytical calculation is performed to obtain the initial analytical results before correction.

[0094] Taking the locations at different electrical distances from the 35kV busbar as the analysis object, the initial analysis results before correction showed that the short-circuit current was at a relatively high level near the busbar, for example, at a distance of about 0.5km from the busbar, the short-circuit current was about 11.5kA; as the electrical distance increased, the short-circuit current decreased significantly, dropping to about 9.0kA near a distance of about 2.5km from the busbar; further extending along the collector line to the far end, near some collection areas, due to the contribution of parallel branches, the short-circuit current rebounded to a certain extent, reaching about 10.8kA at a distance of about 5.5km from the busbar.

[0095] After obtaining the initial short-circuit current analysis results, the short-circuit injection model of the wind turbines was modified based on the short-circuit injection deviation at each wind turbine grid connection node. During the modification process, the relationship between the injection current amplitude of the wind turbine under short-circuit conditions and its operating state and voltage level was constrained to ensure that the injection model remained consistent with the network equivalence. Under the constraints of the modified injection model, analytical calculations were performed again on the short-circuit analytical model to obtain the modified final analytical results.

[0096] The corrected short-circuit current distribution is as follows Figure 4As shown, the short-circuit current variation trend is more consistent at different electrical distances. At approximately 0.5 km from the busbar, the short-circuit current adjusts to approximately 9.8 kA; within the range of 2.5 km to 4.5 km from the busbar, the short-circuit current remains between approximately 9.5 kA and 9.9 kA; near the far-end convergence point, the short-circuit current gradually increases, reaching approximately 10.6 kA at approximately 5.5 km from the busbar. In this embodiment, the short-circuit current analysis result is the initial symmetrical effective value under three-phase symmetrical short-circuit conditions, calculated analytically based on a positive-sequence equivalence network. The short-circuit current is expressed as an effective value in kA. It can be seen that the corrected analysis result, while retaining the influence of the collector network's convergence characteristics, makes the short-circuit current distribution more consistent with the overall electrical distance and network equivalence relationship.

[0097] The above embodiments demonstrate that the method of the present invention, without introducing electromagnetic transient simulation, achieves coordinated calculation of short-circuit current distribution by analytically correcting the short-circuit injection model of the wind turbine, and is applicable to short-circuit current analysis scenarios at different grid connection locations within a wind farm.

[0098] like Figure 5 As shown, this invention provides a short-circuit current analysis and calculation system for a wind farm. The system includes: a data acquisition unit for acquiring electrical topology data and operating status data of the wind farm, and constructing an equivalent network model of the wind farm based on the electrical topology data; a model generation unit for constructing a wind turbine short-circuit injection model based on the operating status data, and mapping the wind turbine short-circuit injection model to the equivalent network model to generate a short-circuit analysis model; an analysis unit for acquiring preset short-circuit operating condition parameters, applying short-circuit conditions to the short-circuit analysis model based on the preset short-circuit operating condition parameters, solving for the short-circuit current using analytical calculation, and outputting an initial short-circuit current analysis result; and an output unit for correcting the wind turbine short-circuit injection model based on the initial short-circuit current analysis result, and performing analytical calculation again on the short-circuit analysis model under the constraints of the corrected wind turbine short-circuit injection model to output a target short-circuit current analysis result.

[0099] The present invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described method for analyzing and calculating short-circuit currents inside a wind farm.

[0100] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 6As shown, the computer device includes a processor A01, a network interface A02, memory (not shown), and a database (not shown) connected via a system bus. The processor A01 provides computing and control capabilities. The memory includes internal memory A03 and a non-volatile storage medium A04. The non-volatile storage medium A04 stores an operating system B01, a computer program B02, and a database (not shown). The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 stored in the non-volatile storage medium A04. The network interface A02 is used for communication with external terminals via a network connection. When the processor A01 executes the computer program B02, it implements a method for analytical calculation of short-circuit current within a wind farm.

[0101] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0102] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0103] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. An analytical calculation method for short-circuit current inside a wind farm, characterized in that, The method includes: Acquire electrical topology data and operational status data of the wind farm, and construct an equivalent network model of the wind farm based on the electrical topology data; Based on the operating status data, a short-circuit injection model for the wind turbine is constructed, and the short-circuit injection model for the wind turbine is mapped to the equivalent network model to generate a short-circuit analytical model. Obtain preset short-circuit condition parameters, apply short-circuit conditions to the short-circuit analytical model based on the preset short-circuit condition parameters, solve the short-circuit current using analytical calculation, and output the initial short-circuit current analytical result; Based on the initial short-circuit current analysis results, the wind turbine short-circuit injection model is corrected, and under the constraints of the corrected wind turbine short-circuit injection model, the short-circuit analysis model is analyzed again to output the target short-circuit current analysis results.

2. The analytical calculation method for short-circuit current inside a wind farm according to claim 1, characterized in that, Based on the electrical topology data, an equivalent network model of the wind farm is constructed, including: Based on the electrical topology data, identify each electrical node in the wind farm and the connection relationship between the nodes, and generate a node set consisting of wind turbine grid-connected nodes, collection line nodes and collection nodes; Based on the node set and the connection relationship, a corresponding node number is assigned to each node, and a node admittance relationship description is established based on the node number; Based on the node admittance relationship description and the corresponding line parameter data and transformer parameter data in the electrical topology data, a node admittance matrix is ​​constructed to characterize the electrical connection characteristics of the wind farm, serving as an equivalent network model of the wind farm.

3. The analytical calculation method for short-circuit current inside a wind farm according to claim 2, characterized in that, Based on the nodal admittance relationship description and the corresponding line parameter data and transformer parameter data in the electrical topology data, a nodal admittance matrix is ​​constructed to characterize the electrical connection characteristics of the wind farm, including: Based on the node admittance relationship description, the node pairs corresponding to each off-diagonal element in the node admittance matrix are determined, and the branch admittance values ​​between each determined node pair are calculated according to the line parameter data. Based on the transformer parameter data, the equivalent admittance parameter corresponding to each transformer is calculated, and the equivalent admittance parameter is mapped to the corresponding node position in the node admittance matrix; Based on the branch admittance value and equivalent admittance parameter corresponding to each node, the diagonal elements of the node admittance matrix are summed and calculated to form the node self-admittance value that satisfies the node current balance relationship. The admittance relationship containing the off-diagonal elements and the diagonal elements is determined as the node admittance matrix for short-circuit analytical calculation.

4. The analytical calculation method for short-circuit current inside a wind farm according to claim 1, characterized in that, Based on the aforementioned operating status data, a short-circuit injection model for wind turbines is constructed, including: Based on the aforementioned operating status data, the voltage state variables and power injection state variables corresponding to each wind turbine grid connection node are extracted and used as the initial state input for the wind turbine short-circuit injection model. Based on the initial state input, the equivalent injection form of each wind turbine under short-circuit conditions is determined, and the corresponding wind turbine short-circuit injection model parameter set is constructed. The short-circuit injection model parameter set of the wind turbine is associated and mapped with each wind turbine grid connection node to obtain the short-circuit injection model of the wind turbine.

5. The analytical calculation method for short-circuit current inside a wind farm according to claim 4, characterized in that, The wind turbine short-circuit injection model is mapped onto the equivalent network model to generate a short-circuit analytical model, including: Based on the grid connection node identifier of the wind turbine corresponding to the wind turbine short-circuit injection model, the injection node position of the wind turbine short-circuit injection model in the equivalent network model is determined. The short-circuit injection model of each wind turbine is introduced as a node injection term into the corresponding node position in the equivalent network model to form a unified network representation that includes node admittance relationship and node injection relationship; The network representation containing the node admittance relationship and the node injection relationship is determined as the short-circuit analytical model for short-circuit current analytical calculation.

6. The analytical calculation method for short-circuit current inside a wind farm according to claim 1, characterized in that, Obtain preset short-circuit condition parameters, apply the short-circuit condition to the short-circuit analytical model based on the preset short-circuit condition parameters, solve for the short-circuit current using analytical calculation, and output the initial short-circuit current analytical result, including: Based on preset short-circuit operating parameters, the corresponding short-circuit node positions and short-circuit connection relationships in the short-circuit analytical model are determined; At the location of the short-circuit node, a short-circuit constraint relationship corresponding to the preset short-circuit condition parameters is introduced to form a short-circuit analytical model after applying the short-circuit condition. Under the constraints of the short-circuit analytical model after applying the short-circuit condition, the node current relationship in the short-circuit analytical model is solved by analytical calculation to obtain the short-circuit current analytical value corresponding to each node. The summation of the short-circuit current analysis values ​​corresponding to each node is determined as the initial short-circuit current analysis result.

7. The analytical calculation method for short-circuit current inside a wind farm according to claim 6, characterized in that, The wind turbine short-circuit injection model is corrected based on the initial short-circuit current analysis results, including: Based on the initial short-circuit current analysis results, the short-circuit injection deviation of each wind turbine is extracted. The short-circuit injection deviation is used to characterize the degree of deviation between the wind turbine short-circuit injection model and the initial short-circuit current analysis results. Based on the short-circuit injection deviation, the injection parameters in the wind turbine short-circuit injection model are corrected to generate a corrected wind turbine short-circuit injection model. The modified wind turbine short-circuit injection model is remapped into the equivalent network model to update the short-circuit analytical model.

8. The analytical calculation method for short-circuit current inside a wind farm according to claim 7, characterized in that, Under the constraints of the modified wind turbine short-circuit injection model, the short-circuit analytical model is recalculated analytically, and the analytical results of the target short-circuit current are output, including: Under the constraints of the modified wind turbine short-circuit injection model, the node injection relationship and node admittance relationship in the short-circuit analytical model are reconstructed in a consistent manner based on the preset short-circuit operating parameters. After completing the consistency reconstruction of the node injection relationship and the node admittance relationship, analytical calculations are performed on the short-circuit analytical model to obtain the short-circuit current analytical quantity that reflects the corrected short-circuit injection characteristics of the wind turbine, which is used as the target short-circuit current analytical result.

9. A system for analyzing and calculating short-circuit current inside a wind farm, characterized in that, The system includes: The data acquisition unit is used to acquire electrical topology data and operating status data of the wind farm, and to construct an equivalent network model of the wind farm based on the electrical topology data. The model generation unit is used to construct a wind turbine short-circuit injection model based on the operating status data, and map the wind turbine short-circuit injection model to the equivalent network model to generate a short-circuit analytical model. The analysis unit is used to obtain preset short-circuit condition parameters, apply short-circuit conditions to the short-circuit analytical model based on the preset short-circuit condition parameters, solve the short-circuit current using analytical calculation, and output the initial short-circuit current analysis result. The output unit is used to correct the wind turbine short-circuit injection model based on the initial short-circuit current analysis result, and to perform analytical calculation on the short-circuit analysis model again under the constraints of the corrected wind turbine short-circuit injection model, and output the target short-circuit current analysis result.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the analytical calculation method for short-circuit current inside a wind farm as described in any one of claims 1-8.

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