Method and device for identifying risk area of power grid from perspective of generalized short-circuit ratio sensitivity

Abstract

This invention discloses a method and apparatus for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity, relating to the field of AC / DC power system safety and stability analysis. The method includes: determining the generalized short-circuit ratio of the target power grid's DC connection point, and determining the partial derivative relationship of the generalized short-circuit ratio with respect to the elements of the original node impedance matrix of the target power grid; determining the influence path of internal component parameters on the stability of the target power grid through the impedance matrix based on the partial derivative relationship; constructing a local-global information transmission chain for the target power grid based on the influence path; performing local perturbations on each transmission line in the target power grid based on the local-global information transmission chain, and determining the sensitivity of each transmission line's line impedance to the generalized short-circuit ratio based on the local perturbation results; constructing a power grid topology model of the target power grid, and determining the electrical distance between the power grid nodes and the DC connection point based on the power grid topology model; and identifying risk areas of the target power grid based on the sensitivity and electrical distance.

Description

Technical Field

[0001] This invention relates to the field of AC / DC power system safety and stability analysis, and in particular to a method and apparatus for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity. Background Technology

[0002] my country's energy resources and load centers exhibit an inverse distribution pattern, with new energy power generation bases often located far from densely populated electricity-consuming areas. Their transmission distances have exceeded the economically viable range of traditional ultra-high-voltage AC transmission. Grid-commutated converter-type high-voltage direct current (LCC-HVDC) transmission technology, with its advantages of large transmission capacity and low transmission loss, has been widely applied in cross-regional high-power transmission, forming a complex grid structure with multiple DC feeders. However, the stable operation of LCC-HVDC systems highly depends on the receiving-end AC grid providing sufficient voltage support, i.e., "system strength." Insufficient system strength can easily lead to commutation failure, voltage collapse, or even cascading grid disconnection accidents. Therefore, quickly and accurately identifying risk areas in the power grid—that is, locating the weak links that have the greatest impact on system stability and whose failure would lead to serious consequences—is an urgent requirement for ensuring the safe operation of modern large power grids.

[0003] Currently, the entire power grid is typically compressed into a single equivalent impedance value, and risk areas are identified based on this equivalent impedance value. However, this method of risk area identification masks the influence of the internal structure of the power grid, thus failing to accurately identify risk areas. Summary of the Invention

[0004] This invention provides a method and apparatus for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity, which mainly improves the accuracy of power grid risk area identification.

[0005] According to a first aspect of the present invention, a method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity is provided, comprising: Determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid. Based on the partial derivative relationship, determine the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix. Based on the influence path, a local-global information transmission chain is constructed for the target power grid, wherein the line impedance of each transmission line in the target power grid is used as a local disturbance source in the local-global information transmission chain, and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target in the local-global information transmission chain. Based on the local-global information transmission chain, local disturbances are performed on each transmission line in the target power grid, and the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio is determined based on the results of the local disturbances. A power grid topology model of the target power grid is constructed, and the electrical distance between the power grid nodes and the DC grid connection point is determined based on the power grid topology model. In this model, the substations in the target power grid are used as nodes in the power grid topology model, the transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model. The risk areas of the target power grid are identified based on the sensitivity and the electrical distance.

[0006] Optionally, the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio is determined based on the local disturbance results, including: Take any transmission line in the target power grid as a target transmission line, determine the reference operating mode of the target power grid, take the target transmission line as the disturbance object, and obtain the original line impedance of the disturbance object under the reference operating mode and the reference generalized short-circuit ratio of the DC grid connection point at this time. The original line impedance of the disturbance object is perturbed according to a preset ratio to obtain the new line impedance after perturbation, and the generalized short-circuit ratio of the DC grid connection point after perturbation is recalculated based on the new line impedance. Based on the disturbance amount of the original line impedance, the reference generalized short-circuit ratio, and the generalized short-circuit ratio after the disturbance, the sensitivity of the line impedance of the target transmission line to the generalized short-circuit ratio is determined.

[0007] Optionally, identifying the risk area of ​​the target power grid based on the sensitivity and the electrical distance includes: The sensitivity and electrical distance of each transmission line are normalized to obtain the normalized sensitivity and the normalized electrical distance. The weighting coefficients corresponding to the normalized sensitivity and the normalized electrical distance are determined respectively. Based on the weighting coefficients, the normalized sensitivity and the normalized electrical distance of the same transmission line are weighted and multiplied to obtain the risk assessment value of each transmission line. The average risk assessment value of transmission lines in each region of the target power grid is determined, and risk areas are divided into each region based on the average risk assessment value.

[0008] Optionally, determining the electrical distance between a grid node and a DC grid connection point based on the grid topology model includes: Each grid node in the power grid topology model is taken as a target grid node, and the DC grid connection point is taken as a source node. The minimum impedance path from the source node to the target grid node is determined, and the total impedance accumulation value of the minimum impedance path is determined. The total impedance accumulation value is taken as the electrical distance between the target grid node and the DC grid connection point.

[0009] Optionally, before determining the partial derivative relationships of the matrix elements in the original nodal impedance matrix of the target power grid relative to the generalized short-circuit ratio, the method further includes: Determine the line structure and internal component parameters of the target power grid; The node admittance matrix of the target power grid is determined based on the line structure and the internal component parameters, and the original node impedance matrix characterizing the electrical connection relationship of the target power grid is determined based on the node admittance matrix.

[0010] Optionally, determining the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original nodal impedance matrix of the target power grid includes: Determine the perturbation inverse matrix of the node admittance matrix caused by the change in line impedance of any transmission line in the target power grid. Based on the inverse disturbance matrix and the original node impedance matrix, determine the analytical partial derivative matrix of the original node impedance matrix with respect to the line impedance of the arbitrary transmission line. The equivalent short-circuit impedance of the DC grid connection point is determined. The rate of change of impedance elements related to the DC grid connection point is extracted from the analytical partial derivative matrix. Based on the rate of change of impedance elements, the partial derivative of the equivalent short-circuit impedance with respect to the line impedance of the arbitrary transmission line is determined. Based on the partial derivative, the relationship between the partial derivatives of the generalized short-circuit ratio and the matrix elements in the original node impedance matrix of the target power grid is determined.

[0011] Optionally, after identifying the risk area of ​​the target power grid based on the sensitivity and the electrical distance, the method further includes: Establish a mapping relationship library between risk level and visual attributes, determine the risk level of each risk area of ​​the target power grid, and assign exclusive visual attributes to each risk level area based on the mapping relationship library, wherein the exclusive visual attributes include at least one of color identification and line style; The target risk level region to which each transmission line belongs in the power grid topology model is determined. The target risk level region is rendered based on the exclusive visual attributes assigned to each risk level region. A risk heat map of the target power grid is generated based on the rendering results.

[0012] According to a second aspect of the present invention, a power grid risk area identification device from the perspective of generalized short-circuit ratio sensitivity is provided, comprising: The determining unit is used to determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and to determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid, and to determine the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix based on the partial derivative relationship. The first construction unit is used to construct a local-global information transmission chain of the target power grid based on the influence path, wherein the line impedance of each transmission line in the target power grid is used as a local disturbance source in the local-global information transmission chain, and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target of the local-global information transmission chain. The disturbance unit is used to perform local disturbances on each transmission line in the target power grid based on the local-global information transmission chain, and to determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio based on the local disturbance results. The second construction unit is used to construct a power grid topology model of the target power grid and determine the electrical distance between power grid nodes and DC grid connection points based on the power grid topology model. In this model, substations in the target power grid are used as nodes in the power grid topology model, transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model. An identification unit is used to identify the risk area of ​​the target power grid based on the sensitivity and the electrical distance.

[0013] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity.

[0014] According to a fourth aspect of the present invention, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-mentioned method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity.

[0015] The present invention provides a method and apparatus for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity. Compared with the current method of compressing the entire power grid into a single equivalent impedance value and identifying power grid risk areas based on the equivalent impedance value, the present invention, by determining the partial derivative relationship of the generalized short-circuit ratio with respect to the elements of the original node impedance matrix, can directly analyze the contribution of internal component parameters to power grid stability, avoiding information loss and thus enabling more accurate assessment of power grid stability. By constructing a local-global information transmission chain, the present invention links local transmission line impedance changes with global DC grid connection point stability indicators, abstracting the complex power grid into a clear causal chain, reducing cognitive complexity, and thus improving the efficiency and accuracy of subsequent power grid risk area identification. By comprehensively analyzing sensitivity and electrical distance, and combining these two key indicators, the present invention can more accurately identify risk areas in the target power grid. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This invention provides a flowchart of a power grid risk area identification method from the perspective of generalized short-circuit ratio sensitivity. Figure 2 This diagram illustrates a multi-port Thevenin equivalent provided by an embodiment of the present invention. Figure 3 This invention provides a flowchart of another method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity. Figure 4 This diagram illustrates the structure of a power grid risk area identification device from the perspective of generalized short-circuit ratio sensitivity, as provided in an embodiment of the present invention. Figure 5 This invention provides a schematic diagram of the structure of another power grid risk area identification device from the perspective of generalized short-circuit ratio sensitivity. Figure 6 A schematic diagram of the physical structure of a computer device provided in an embodiment of the present invention is shown. Detailed Implementation

[0017] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0018] Currently, the common practice of compressing the entire power grid into a single equivalent impedance value and identifying risk areas based on this equivalent impedance value masks the influence of the internal structure of the power grid, thus failing to accurately identify risk areas.

[0019] To address the aforementioned problems, embodiments of the present invention provide a method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity, such as... Figure 1 As shown, the method includes: 101. Determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid. Based on the partial derivative relationship, determine the influence path of internal component parameters on the stability of the target power grid through the impedance matrix.

[0020] The target power grid refers to a power system that includes at least one DC converter station (i.e., DC grid connection point) and its connected AC network; the current operating mode refers to the set of all generator output, load size, line switching status and transformer tap positions in the power grid at a specific time (such as peak load, maintenance mode, etc.); internal components refer to the physical equipment that constitutes the power grid, and the parameters of internal components include the impedance of transmission lines, the leakage reactance of transformers, the admittance of shunt reactors / capacitors, etc.

[0021] In this embodiment of the invention, the topology and component parameters of the target power grid under the current operating mode are obtained. Based on the above data, a node admittance matrix of the target power grid is established. The original node impedance matrix is ​​obtained by performing an inverse operation on the node admittance matrix. The matrix elements in the original node impedance matrix... Let be the Thevenin equivalent impedance as seen from node i, and let be the voltage rise at node j when a unit current is injected into node i. Determine the DC grid connection point where the DC converter station is located in the target power grid, using the diagonal elements of the original node impedance matrix. Calculate the equivalent short-circuit capacity of node k The formula is shown below:

[0022] in, Given the current per-unit operating voltage of node k, the generalized short-circuit ratio is then calculated using the following formula. :

[0023] in, This represents the sum of the rated power of the converter station and other DC systems with similar electrical distances. Furthermore, a generalized short-circuit ratio is first established. For the diagonal elements of the original nodal impedance matrix The partial derivatives of are given by the following relationship:

[0024] For high-voltage power grids, reactance plays a dominant role, and the simplified partial derivative relationship is approximated as follows:

[0025] in, This represents the sum of the rated power of all DC systems at the DC grid connection point and in its electrical vicinity. This partial derivative relationship quantifies the rate at which the generalized short-circuit ratio changes when a specific element in the impedance matrix undergoes a small change.

[0026] Furthermore, using the generalized short-circuit ratio of the DC grid connection point as the dependent variable and the key elements in the original node impedance matrix (the self-impedance of the DC grid connection point and related mutual impedances) as the independent variables, the first partial derivative is directly calculated. This first partial derivative quantifies the immediate impact rate of small fluctuations in the impedance matrix elements on the overall system stability index, establishing the dependence of stability on the equivalent impedance of the power grid. Using the matrix perturbation theory or the correction formula in the impedance matrix forming algorithm, the analytical expression for the change in impedance matrix elements caused by changes in any internal component parameter (such as the impedance of a transmission line) is derived as the second partial derivative. Using the chain rule in multivariable calculus, the above two layers of partial derivatives are multiplied to form the influence path. The "influence path" is a mathematical logic chain that quantifies causal transmission. It is a sensitivity transmission channel describing how local disturbances (such as changes in the impedance of a line) are amplified or attenuated through the coupling of the power grid topology and ultimately transformed into a global response (such as changes in the generalized short-circuit ratio of the system). By determining the partial derivative relationship between the generalized short-circuit ratio and the elements of the original node impedance matrix, this invention can directly analyze the contribution of internal component parameters to grid stability, avoiding information loss and thus enabling a more accurate assessment of grid stability.

[0027] 102. Construct a local-global information transmission chain for the target power grid based on the influence path. In this chain, the line impedance of each transmission line in the target power grid is used as a local disturbance source and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target.

[0028] In this embodiment of the invention, the line impedance of each transmission line in the target power grid is taken as the local disturbance source in the local-global information transmission chain, and the influencing path is taken as the transmission medium in the local-global information transmission chain, which is the transmission mechanism of the change in the node impedance matrix elements. The generalized short-circuit ratio of the DC grid connection point is taken as the global observation target of the local-global information transmission chain. Based on the above information, the functional relationship of the local-global information transmission chain is constructed as follows:

[0029] in, For the complete transmission process, This represents the change in line impedance of the transmission line. This refers to the change in the generalized short-circuit ratio. This invention, through the construction of a local-global information transmission chain, links local transmission line impedance changes with global DC grid connection point stability indicators. This abstracts the complex power grid into a clear causal chain, reducing cognitive complexity and thus improving the efficiency and accuracy of subsequent power grid risk area identification.

[0030] 103. Based on the local-global information transmission chain, perform local perturbation on each transmission line in the target power grid, and determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio based on the results of the local perturbation.

[0031] In this embodiment of the invention, each independent transmission circuit is considered an independent local disturbance source. Taking any transmission line as the target transmission line as an example, the disturbance step size is preset. Based on the perturbation step size The impedance of the target transmission line is perturbed, and the sensitivity of the line impedance to the generalized short-circuit ratio is determined based on the generalized short-circuit ratio before and after the perturbation. Thus, the sensitivity of the line impedance to the generalized short-circuit ratio of each transmission line can be determined in the above manner.

[0032] Specifically, if the target power grid has N nodes, n DC grid connection points need to be extracted from them as multi-port Thevenin equivalent ports, such as... Figure 2 The diagram shows a multi-port Thevenin equivalent network, where 'a' represents the network before equivalence and 'b' represents the network after equivalence. The ports are denoted by subscripts "α, β, ..., n", and the corresponding node pairs on each port are denoted by "(1, -1'), (2, -2'), ..., (p, -p'), ..., (n, -n')".

[0033] Let the original nodal impedance matrix be:

[0034] The equivalent impedance matrix is:

[0035] The first terminal is positive in the direction of the current flowing out of the network, and the second terminal is positive in the direction of the current flowing into the network. A node-port column vector is introduced. By forming a matrix from the column vectors, we obtain .

[0036] Let Z eq,ij The isovalue matrix Z eqThe elements of the matrix, when i ≠ j, represent the mutual impedance between the two DC lines; when i = j, they represent the self-impedance at the grid connection point of the DC line. This is to study the equivalent impedance matrix Z. eq The analytical relationship between the elements and the elements of the original nodal impedance matrix Z is as follows: Let equivalent node i correspond to the (m, -m') node pair of the target power grid, and equivalent node j correspond to the (x, -x') node pair. Then the elements after equivalence are:

[0037] From the above formula, the equivalent impedance matrix Z can be obtained. eq The elements in the matrix are linearly related to the elements in the original nodal impedance matrix Z. Let... The equivalent impedance matrix Z is respectively eq The left and right feature vectors, The equivalent impedance matrix Z eq If a certain eigenvalue is given, then we have

[0038] Transposing both sides of the equation yields...

[0039] Among them, P N As the projection matrix, taking the partial derivative with respect to the DC grid connection impedance yields:

[0040] Expanding the above formula yields its sensitivity matrix;

[0041] Z eq,ij The node impedance variable with respect to Z mm’ The function can be obtained by the chain rule:

[0042] The sensitivity of the generalized short-circuit ratio before equivalence can be calculated using this formula.

[0043] 104. Construct a power grid topology model of the target power grid, and determine the electrical distance between power grid nodes and DC grid connection points based on the power grid topology model. In this model, substations in the target power grid are used as nodes in the power grid topology model, transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model.

[0044] In this embodiment of the invention, a power grid topology model is constructed using substations as nodes, transmission lines between substations as edges between nodes, and the line impedance of the transmission lines as the weights of the edges between nodes. Based on the power grid topology model, the minimum impedance from each node to the DC grid connection point and the electrical distance from the corresponding node to the DC grid connection point are calculated.

[0045] 105. Identify risk areas of target power grids based on sensitivity and electrical distance.

[0046] In this embodiment of the invention, risk areas in the target power grid are identified through a comprehensive analysis of sensitivity and electrical distance. Specifically, high-risk, medium-risk, low-to-medium-risk, and low-risk areas are identified within each region of the target power grid. By combining these two key indicators through comprehensive analysis, this embodiment of the invention can more accurately identify risk areas in the target power grid.

[0047] The present invention provides a method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity. Compared with the current method that typically compresses the entire power grid into a single equivalent impedance value and identifies power grid risk areas based on the equivalent impedance value, this invention determines the partial derivative relationship of the generalized short-circuit ratio with respect to the elements of the original node impedance matrix. This allows for direct analysis of the contribution of internal component parameters to power grid stability, avoiding information loss and thus enabling more accurate assessment of power grid stability. By constructing a local-global information transmission chain, the method links local transmission line impedance changes with global DC grid connection point stability indicators, abstracting the complex power grid into a clear causal chain, reducing cognitive complexity, and thus improving the efficiency and accuracy of subsequent power grid risk area identification. By comprehensively analyzing sensitivity and electrical distance, and combining these two key indicators, the method can more accurately identify risk areas in the target power grid.

[0048] Furthermore, to better illustrate the process of identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity, as a refinement and extension of the above embodiments, this invention provides another method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity, such as... Figure 3 As shown, the method includes: 201. Determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid. Based on the partial derivative relationship, determine the influence path of internal component parameters on the stability of the target power grid through the impedance matrix.

[0049] In this embodiment of the invention, in order to determine the partial derivative relationship, it is first necessary to determine the original node impedance matrix. Based on this, the method includes: determining the line structure and internal component parameters of the target power grid; determining the node admittance matrix of the target power grid based on the line structure and the internal component parameters; and determining the original node impedance matrix characterizing the electrical connection relationship of the target power grid based on the node admittance matrix.

[0050] Specifically, static topology data of the target power grid is read from the power grid energy management system (EMS), geographic information system (GIS), or offline planning database. This data includes line structure and internal component parameters. The line structure includes all nodes in the power grid, the branches connecting these nodes, and the starting and ending nodes of each branch. Internal component parameters include the resistance, reactance, capacitance, susceptance, and transformer turns ratio of each branch. To ensure consistency in the calculations, all collected data is converted to per-unit values. Based on the processed line structure and component parameters, Kirchhoff's current law is used to calculate self-admittance and mutual admittance. A node admittance matrix is ​​formed based on the self-admittance and mutual admittance, which describes the node current-voltage relationship of the target power grid in the frequency domain. Then, the inverse operation of the node admittance matrix is ​​performed, i.e., the inverse matrix of the node admittance matrix is ​​obtained as the original node impedance matrix.

[0051] Furthermore, after determining the original node impedance matrix, it is also necessary to determine the partial derivative relationship of the matrix elements in the original node impedance matrix of the target power grid with respect to the generalized short-circuit ratio. Based on this, step 201 specifically includes: determining the perturbation reciprocal matrix of the line impedance change of any transmission line in the target power grid with respect to the node admittance matrix; determining the analytical partial derivative matrix of the original node impedance matrix with respect to the line impedance of the arbitrary transmission line based on the perturbation reciprocal matrix and the original node impedance matrix; determining the equivalent short-circuit impedance of the DC grid connection point; extracting the rate of change of impedance elements related to the DC grid connection point from the analytical partial derivative matrix; determining the partial derivative of the equivalent short-circuit impedance with respect to the line impedance of the arbitrary transmission line based on the rate of change of impedance elements; and determining the partial derivative relationship of the matrix elements in the original node impedance matrix of the target power grid with respect to the generalized short-circuit ratio based on the partial derivative.

[0052] Specifically, for any transmission line to be analyzed in the target power grid, the incremental matrix of the node admittance matrix caused by a small change in its impedance is calculated. Based on the structural characteristics of this incremental matrix, a disturbance reciprocal matrix characterizing the local disturbance is constructed. The core elements of the disturbance reciprocal matrix are uniquely determined by the change in line impedance and its topological position in the admittance matrix. Using the matrix inversion lemma, combined with the original node impedance matrix and the aforementioned disturbance reciprocal matrix, the analytical partial derivative matrix of the original node impedance matrix with respect to the line impedance is directly derived. Further, the DC grid connection point is locked, and the rate of change of row and column elements related to that node is extracted from the analytical partial derivative matrix. These rates of change are substituted into the definition of equivalent short-circuit impedance, and the equivalent short-circuit impedance is calculated using the chain rule. For line impedance partial derivatives Then based on the generalized short-circuit ratio With equivalent short-circuit impedance The functional relationship of the equivalent short-circuit impedance Differentiation yields Then the partial derivatives and partial derivatives By multiplying these components, the partial derivative relationships of the generalized short-circuit ratio with respect to the matrix elements of the original node impedance matrix are established. Finally, based on these partial derivative relationships, the influence path of internal component parameters on the target power grid stability through the impedance matrix is ​​determined.

[0053] 202. Construct a local-global information transmission chain for the target power grid based on the influence path. In this chain, the line impedance of each transmission line in the target power grid is used as a local disturbance source and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target.

[0054] Specifically, the target power grid is abstracted as a multi-input, single-output sensitivity transfer network. This network uses the line impedance of each transmission line as a parallel local disturbance source (input), and the generalized short-circuit ratio of the DC grid connection point as the unique global observation target (output). The previously calculated "influence path" is instantiated as a weighted transmission coefficient in the transfer chain. For any k-th line, its corresponding total sensitivity is used as the transfer gain of that branch, establishing a linear mapping relationship from the local disturbance source to the global observation target. The sensitivity coefficients of all transmission lines are summarized to construct a global sensitivity vector. This vector, together with the local disturbance vector, constitutes a complete local-global information transfer chain. In this chain, any small change in the impedance of any line (local information) can be transmitted in real time and quantitatively and transformed into an impact on the system's generalized short-circuit ratio (global information), thereby achieving transparent analysis and rapid deduction of the power grid stability state.

[0055] 203. Based on the local-global information transmission chain, perform local perturbation on each transmission line in the target power grid, and determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio based on the results of the local perturbation.

[0056] In this embodiment of the invention, after determining the local-global information transmission chain, it is necessary to determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio based on the local-global information transmission chain. Based on this, step 203 specifically includes: taking any transmission line in the target power grid as a target transmission line, determining the reference operating mode of the target power grid, taking the target transmission line as a disturbance object, obtaining the original line impedance of the disturbance object under the reference operating mode and the reference generalized short-circuit ratio of the DC grid connection point at this time; applying a disturbance to the original line impedance of the disturbance object based on a preset ratio to obtain the new line impedance after disturbance, and recalculating the post-disturbance generalized short-circuit ratio of the DC grid connection point based on the new line impedance; and determining the sensitivity of the line impedance of the target transmission line to the generalized short-circuit ratio based on the disturbance amount of the original line impedance, the reference generalized short-circuit ratio, and the post-disturbance generalized short-circuit ratio.

[0057] Specifically, any transmission line to be analyzed within the target power grid is selected as the "target transmission line," while keeping the topology and parameters of the rest of the power grid unchanged. The current system operating mode is defined as the baseline operating mode. In this state, the original line impedance of the target transmission line is recorded. The reference generalized short-circuit ratio corresponding to the DC grid connection point was calculated. Based on the preset perturbation ratio The original impedance of the target transmission line is corrected to generate a new line impedance after disturbance. Based on the updated grid parameters (i.e., only the target line impedance was replaced, while the rest remained unchanged), the process of constructing the nodal admittance matrix, inverting the impedance matrix, and calculating the equivalent short-circuit impedance was re-executed to calculate the generalized short-circuit ratio of the DC grid connection point under disturbance conditions. Using the finite difference formula, combined with impedance perturbation... The change in the generalized short-circuit ratio The sensitivity S of the target transmission line is calculated as follows:

[0058] 204. Construct a power grid topology model of the target power grid, and determine the electrical distance between power grid nodes and DC grid connection points based on the power grid topology model. In this model, substations in the target power grid are used as nodes in the power grid topology model, transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model.

[0059] In this embodiment of the invention, in order to increase the accuracy of identifying power grid risk areas, it is also necessary to determine the electrical distance between the power grid node and the DC grid connection point. Based on this, step 204 specifically includes: taking any power grid node in the power grid topology model as a target power grid node, taking the DC grid connection point as a source node, determining the minimum impedance path from the source node to the target power grid node, determining the total impedance accumulation value of the minimum impedance path, and taking the total impedance accumulation value as the electrical distance between the target power grid node and the DC grid connection point.

[0060] Specifically, the DC grid connection point is designated as the unique source node in the topology network. Then, each AC node in the power grid topology model is traversed and sequentially designated as the current target grid node. For each "source node - target node" combination, the impedance value (resistance, reactance, or its magnitude) of the transmission line is used as the edge weight. A shortest path search algorithm (such as Dijkstra's algorithm or Floyd-Warshall's algorithm) is used to search for the minimum impedance path from the source node to the target node in the topology network. This path represents the physical channel with the minimum equivalent impedance encountered when current flows between two points. The impedances of all branches included in the minimum impedance path are extracted and algebraically summed to obtain the total impedance sum of the path. This value eliminates the complexity interference of parallel branches or multi-ring network structures and directly reflects the impedance characteristics of a single dominant path. The calculated total impedance sum is directly defined as the electrical distance between the target grid node and the DC grid connection point. The smaller this distance, the closer the electrical connection between the node and the DC grid connection point, and the more significant their mutual influence; conversely, a larger distance indicates a weaker electrical connection. By traversing the entire network, a network node electrical distance distribution map centered on the DC grid connection point is finally generated.

[0061] 205. Normalize the sensitivity and electrical distance for each transmission line to obtain the normalized sensitivity and normalized electrical distance.

[0062] Specifically, the sensitivity and electrical distance corresponding to each transmission line are compressed into the (0,1) interval to achieve normalization of the above data.

[0063] 206. Determine the weighting coefficients corresponding to the normalized sensitivity and normalized electrical distance respectively. Based on the weighting coefficients, perform a weighted multiplication of the normalized sensitivity and normalized electrical distance of the same transmission line to obtain the risk assessment value of each transmission line.

[0064] 207. Determine the average risk assessment value of transmission lines in each region of the target power grid, and divide each region into risk areas based on the average risk assessment value.

[0065] Specifically, based on the operating characteristics of the target power grid or expert experience, the weighting coefficients for normalized sensitivity and normalized electrical distance are set respectively, as follows: , ,in, For each transmission line i in the target power grid, normalize its sensitivity. With normalized electrical distance The risk assessment value of the route is obtained by performing a weighted multiplication operation. :

[0066] Furthermore, the target power grid is pre-divided into several physical areas or electrical zones. For each area, the risk assessment values ​​of all transmission lines contained within the area are statistically analyzed, and their arithmetic mean is calculated to obtain the regional risk assessment mean of the area. The target risk threshold interval to which the regional risk assessment mean belongs is determined. Each risk threshold interval corresponds to a risk level. Finally, the risk level corresponding to the target risk threshold interval is taken as the risk level of the area. In this way, risk areas with different risk levels of the target power grid can be identified.

[0067] Furthermore, to clearly understand the risk areas of the power grid, it is also necessary to draw a risk heat map. Based on this, the method includes: establishing a mapping relationship library between risk levels and visual attributes; determining the risk level of each risk area of ​​the target power grid; assigning a unique visual attribute to each risk level area based on the mapping relationship library, wherein the unique visual attribute includes at least one of color identification and line style; determining the target risk level area to which each transmission line in the power grid topology model belongs; rendering the target risk level area based on the unique visual attribute assigned to each risk level area; and generating a risk heat map of the target power grid based on the rendering result.

[0068] Specifically, a standardized mapping database is pre-established, defining a one-to-one correspondence between different risk levels (such as "high risk," "medium risk," and "low risk") and exclusive visual attributes. Color coding employs a color gradient strategy, mapping high-risk areas to red, medium-risk areas to yellow, and low-risk areas to green, leveraging the human eye's sensitivity to color to quickly distinguish risk levels. Line styles are enhanced with variations in line type to improve recognizability; for example, high-risk areas use thick solid lines or flashing dashed lines, medium-risk areas use standard solid lines, and low-risk areas use thin dashed lines or dotted lines. This database supports dynamic configuration, allowing users to adjust color thresholds or line type combinations according to actual display needs. Each transmission line in the power grid topology model is traversed, and its physical or electrical partition is analyzed to determine the target risk level area to which the line belongs. Then, the mapping database is queried to extract the exclusive visual attributes corresponding to the target risk level. Based on the geometric coordinate data of the power grid topology model, a graphics rendering engine is invoked to apply the extracted exclusive visual attributes to the corresponding transmission line elements in real time. For example, lines belonging to high-risk areas are rendered as thick red solid lines; lines belonging to medium / low-risk areas are rendered with the corresponding colors and line types. Finally, all rendered elements are overlaid and synthesized to generate a risk heat map covering the entire network. This heat map not only preserves the topological structure information of the power grid, but also intuitively shows the areas where risks accumulate and the transmission paths in the power grid through the spatial distribution of colors and line types, helping dispatchers quickly locate key potential hazards.

[0069] The present invention provides another method for identifying power grid risk areas from the perspective of generalized short-circuit ratio sensitivity. Compared with the current method that typically compresses the entire power grid into a single equivalent impedance value and identifies power grid risk areas based on the equivalent impedance value, this invention determines the partial derivative relationship of the generalized short-circuit ratio with respect to the elements of the original node impedance matrix. This allows for direct analysis of the contribution of internal component parameters to power grid stability, avoiding information loss and thus enabling more accurate assessment of power grid stability. By constructing a local-global information transmission chain, the invention links local transmission line impedance changes with global DC grid connection point stability indicators, abstracting the complex power grid into a clear causal chain, reducing cognitive complexity, and thus improving the efficiency and accuracy of subsequent power grid risk area identification. By comprehensively analyzing sensitivity and electrical distance, and combining these two key indicators, the invention can more accurately identify risk areas in the target power grid.

[0070] Furthermore, as Figure 1 In specific implementation, embodiments of the present invention provide a power grid risk area identification device from the perspective of generalized short-circuit ratio sensitivity, such as... Figure 4As shown, the device includes: a determining unit 31, a first constructing unit 32, a disturbance unit 33, a second constructing unit 34, and an identification unit 35.

[0071] The determining unit 31 can be used to determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and to determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid, and to determine the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix based on the partial derivative relationship.

[0072] The first construction unit 32 can be used to construct a local-global information transmission chain of the target power grid based on the influence path, wherein the line impedance of each transmission line in the target power grid is used as a local disturbance source in the local-global information transmission chain, and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target of the local-global information transmission chain.

[0073] The disturbance unit 33 can be used to locally disturb each transmission line in the target power grid based on the local-global information transmission chain, and determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio based on the local disturbance results.

[0074] The second construction unit 34 can be used to construct a power grid topology model of the target power grid, and determine the electrical distance between power grid nodes and DC grid connection points based on the power grid topology model. In this model, substations in the target power grid are used as nodes in the power grid topology model, transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model.

[0075] The identification unit 35 can be used to identify the risk area of ​​the target power grid based on the sensitivity and the electrical distance.

[0076] In specific application scenarios, in order to determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio, such as... Figure 5 As shown, the disturbance unit 33 includes an acquisition module 331, a disturbance module 332, and a determination module 333.

[0077] The acquisition module 331 can be used to take any transmission line in the target power grid as a target transmission line, determine the reference operating mode of the target power grid, take the target transmission line as a disturbance object, and acquire the original line impedance of the disturbance object under the reference operating mode and the reference generalized short-circuit ratio of the DC grid connection point at this time.

[0078] The disturbance module 332 can be used to apply a disturbance to the original line impedance of the disturbance object based on a preset ratio, obtain a new line impedance after disturbance, and recalculate the generalized short-circuit ratio of the DC grid connection point after disturbance based on the new line impedance.

[0079] The determining module 333 can be used to determine the sensitivity of the target transmission line's line impedance to the generalized short-circuit ratio based on the disturbance amount of the original line impedance, the reference generalized short-circuit ratio, and the generalized short-circuit ratio after the disturbance.

[0080] In specific application scenarios, in order to identify risk areas of the target power grid, the identification unit 35 includes a normalization module 351, a weighting module 352, and a risk classification module 353.

[0081] The normalization module 351 can be used to normalize the sensitivity and electrical distance corresponding to each transmission line, so as to obtain the normalized sensitivity and the normalized electrical distance.

[0082] The weighting module 352 can be used to determine the weighting coefficients corresponding to the normalized sensitivity and the normalized electrical distance, respectively, and to perform a weighted multiplication of the normalized sensitivity and the normalized electrical distance of the same transmission line based on the weighting coefficients to obtain the risk assessment value of each transmission line.

[0083] The risk classification module 353 can be used to determine the average risk assessment value of transmission lines in each region of the target power grid, and classify each region into risk areas based on the average risk assessment value.

[0084] In specific application scenarios, in order to determine the electrical distance between a power grid node and a DC grid connection point, the second construction unit 34 can be used to take any power grid node in the power grid topology model as a target power grid node, take the DC grid connection point as a source node, determine the minimum impedance path from the source node to the target power grid node, determine the total impedance accumulation value of the minimum impedance path, and take the total impedance accumulation value as the electrical distance between the target power grid node and the DC grid connection point.

[0085] In specific application scenarios, in order to determine the original node impedance matrix, the determining unit 31 can also be used to determine the line structure and internal component parameters of the target power grid; determine the node admittance matrix of the target power grid based on the line structure and the internal component parameters; and determine the original node impedance matrix characterizing the electrical connection relationship of the target power grid based on the node admittance matrix.

[0086] In specific application scenarios, in order to determine the partial derivative relationship of matrix elements in the original node impedance matrix of the generalized short-circuit ratio relative to the target power grid, the determining unit 31 can be specifically used to determine the perturbation reciprocal matrix of the line impedance change of any transmission line in the target power grid with respect to the node admittance matrix; based on the perturbation reciprocal matrix and the original node impedance matrix, determine the analytical partial derivative matrix of the original node impedance matrix with respect to the line impedance of the arbitrary transmission line; determine the equivalent short-circuit impedance of the DC grid connection point, extract the rate of change of impedance elements related to the DC grid connection point from the analytical partial derivative matrix, determine the partial derivative of the equivalent short-circuit impedance with respect to the line impedance of the arbitrary transmission line based on the rate of change of impedance elements, and determine the partial derivative relationship of the partial derivative of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid based on the partial derivative.

[0087] In specific application scenarios, in order to construct a risk heat map, the device also includes a heat map construction unit 36.

[0088] The heatmap construction unit 36 ​​can be used to establish a mapping relationship library between risk levels and visual attributes, determine the risk level of each risk area of ​​the target power grid, assign exclusive visual attributes to each risk level area based on the mapping relationship library, wherein the exclusive visual attributes include at least one of color identification and line style; determine the target risk level area to which each transmission line in the power grid topology model belongs, render the target risk level area based on the exclusive visual attributes assigned to each risk level area, and generate a risk heatmap of the target power grid based on the rendering results.

[0089] It should be noted that other corresponding descriptions of the functional modules involved in the power grid risk area identification device from the perspective of generalized short-circuit ratio sensitivity provided in this embodiment of the invention can be found in [reference]. Figure 1 The corresponding description of the method shown will not be repeated here.

[0090] Based on the above, Figure 1The method shown, correspondingly, also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the following steps: determining the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and determining the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid; determining the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix based on the partial derivative relationship; constructing a local-global information transmission chain of the target power grid based on the influence path, wherein the line impedance of each transmission line in the target power grid serves as a local disturbance source in the local-global information transmission chain, and the generalized short-circuit ratio of the DC grid connection point serves as... The local-global information transmission chain is used to observe the global target; based on the local-global information transmission chain, local disturbances are performed on each transmission line in the target power grid, and the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio is determined based on the local disturbance results; a power grid topology model of the target power grid is constructed, and the electrical distance between power grid nodes and DC grid connection points is determined based on the power grid topology model, wherein substations in the target power grid are used as nodes in the power grid topology model, transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model; risk areas of the target power grid are identified based on the sensitivity and the electrical distance.

[0091] Based on the above, Figure 1 The method shown and as Figure 4 The embodiment of the device shown in the invention also provides a physical structure diagram of a computer device, such as... Figure 6As shown, the computer device includes: a processor 41, a memory 42, and a computer program stored in the memory 42 and executable on the processor. Both the memory 42 and the processor 41 are mounted on a bus 43. When the processor 41 executes the program, it performs the following steps: determining the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and determining the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid; determining the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix based on the partial derivative relationship; and constructing a local-global information transmission chain for the target power grid based on the influence path, wherein the line impedance of each transmission line in the target power grid serves as a local disturbance in the local-global information transmission chain. The source and the generalized short-circuit ratio of the DC grid connection point are used as the global observation target of the local-global information transmission chain; based on the local-global information transmission chain, local perturbations are performed on each transmission line in the target power grid, and the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio is determined based on the local perturbation results; a power grid topology model of the target power grid is constructed, and the electrical distance between the power grid nodes and the DC grid connection point is determined based on the power grid topology model, wherein the substations in the target power grid are used as nodes in the power grid topology model, the transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model; the risk areas of the target power grid are identified based on the sensitivity and the electrical distance.

[0092] Through the technical solution of this invention, by determining the partial derivative relationship between the generalized short-circuit ratio and the elements of the original node impedance matrix, the contribution of internal component parameters to grid stability can be directly analyzed, avoiding information loss and thus enabling a more accurate assessment of grid stability. By constructing a local-global information transmission chain, the local transmission line impedance changes are linked to the global DC grid connection point stability index, which can abstract the complex grid into a clear causal chain, reducing cognitive complexity and thus improving the efficiency and accuracy of subsequent grid risk area identification. By comprehensively analyzing sensitivity and electrical distance, and combining these two key indicators, risk areas in the target grid can be identified more accurately.

[0093] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for identifying a risk area of a power grid under a generalized short-circuit ratio (SCR) sensitivity perspective, characterized in that, include: Determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid. Based on the partial derivative relationship, determine the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix. Based on the influence path, a local-global information transmission chain is constructed for the target power grid, wherein the line impedance of each transmission line in the target power grid is used as a local disturbance source in the local-global information transmission chain, and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target in the local-global information transmission chain. Based on the local-global information transmission chain, local disturbances are performed on each transmission line in the target power grid, and the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio is determined based on the results of the local disturbances. A power grid topology model of the target power grid is constructed, and the electrical distance between the power grid nodes and the DC grid connection point is determined based on the power grid topology model. In this model, the substations in the target power grid are used as nodes in the power grid topology model, the transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model. The risk areas of the target power grid are identified based on the sensitivity and the electrical distance.

2. The method of claim 1, wherein, The sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio is determined based on the results of local disturbances, including: Take any transmission line in the target power grid as a target transmission line, determine the reference operating mode of the target power grid, take the target transmission line as the disturbance object, and obtain the original line impedance of the disturbance object under the reference operating mode and the reference generalized short-circuit ratio of the DC grid connection point at this time. The original line impedance of the disturbance object is perturbed according to a preset ratio to obtain the new line impedance after perturbation, and the generalized short-circuit ratio of the DC grid connection point after perturbation is recalculated based on the new line impedance. Based on the disturbance amount of the original line impedance, the reference generalized short-circuit ratio, and the generalized short-circuit ratio after the disturbance, the sensitivity of the line impedance of the target transmission line to the generalized short-circuit ratio is determined.

3. The method of claim 1, wherein, The identification of the risk area of ​​the target power grid based on the sensitivity and the electrical distance includes: The sensitivity and electrical distance of each transmission line are normalized to obtain the normalized sensitivity and the normalized electrical distance. The weighting coefficients corresponding to the normalized sensitivity and the normalized electrical distance are determined respectively. Based on the weighting coefficients, the normalized sensitivity and the normalized electrical distance of the same transmission line are weighted and multiplied to obtain the risk assessment value of each transmission line. The average risk assessment value of transmission lines in each region of the target power grid is determined, and risk areas are divided into each region based on the average risk assessment value.

4. The method of claim 1, wherein, Determining the electrical distance between grid nodes and DC grid connection points based on the aforementioned grid topology model includes: Each grid node in the power grid topology model is taken as a target grid node, and the DC grid connection point is taken as a source node. The minimum impedance path from the source node to the target grid node is determined, and the total impedance accumulation value of the minimum impedance path is determined. The total impedance accumulation value is taken as the electrical distance between the target grid node and the DC grid connection point.

5. The method of claim 1, wherein, Before determining the partial derivative relationships of the matrix elements in the original nodal impedance matrix of the target power grid relative to the generalized short-circuit ratio, the method further includes: Determine the line structure and internal component parameters of the target power grid; The node admittance matrix of the target power grid is determined based on the line structure and the internal component parameters, and the original node impedance matrix characterizing the electrical connection relationship of the target power grid is determined based on the node admittance matrix.

6. The method of claim 5, wherein, Determining the partial derivative relationships of the generalized short-circuit ratio with respect to the original nodal impedance matrix of the target power grid includes: Determine the perturbation inverse matrix of the node admittance matrix caused by the change in line impedance of any transmission line in the target power grid. Based on the inverse disturbance matrix and the original node impedance matrix, determine the analytical partial derivative matrix of the original node impedance matrix with respect to the line impedance of the arbitrary transmission line. The equivalent short-circuit impedance of the DC grid connection point is determined. The rate of change of impedance elements related to the DC grid connection point is extracted from the analytical partial derivative matrix. Based on the rate of change of impedance elements, the partial derivative of the equivalent short-circuit impedance with respect to the line impedance of the arbitrary transmission line is determined. Based on the partial derivative, the relationship between the partial derivatives of the generalized short-circuit ratio and the matrix elements in the original node impedance matrix of the target power grid is determined.

7. The method of claim 1, wherein, After identifying the risk area of ​​the target power grid based on the sensitivity and the electrical distance, the method further includes: Establish a mapping relationship library between risk level and visual attributes, determine the risk level of each risk area of ​​the target power grid, and assign exclusive visual attributes to each risk level area based on the mapping relationship library, wherein the exclusive visual attributes include at least one of color identification and line style; The target risk level region to which each transmission line belongs in the power grid topology model is determined. The target risk level region is rendered based on the exclusive visual attributes assigned to each risk level region. A risk heat map of the target power grid is generated based on the rendering results.

8. A device for identifying a risk area of a power grid under a generalized short-circuit ratio sensitivity perspective, characterized in that, include: The determining unit is used to determine the generalized short-circuit ratio of the DC grid connection point under the current operating mode of the target power grid, and to determine the partial derivative relationship of the generalized short-circuit ratio with respect to the matrix elements in the original node impedance matrix of the target power grid, and to determine the influence path of the internal component parameters on the stability of the target power grid through the impedance matrix based on the partial derivative relationship. The first construction unit is used to construct a local-global information transmission chain of the target power grid based on the influence path, wherein the line impedance of each transmission line in the target power grid is used as a local disturbance source in the local-global information transmission chain, and the generalized short-circuit ratio of the DC grid connection point is used as a global observation target of the local-global information transmission chain. The disturbance unit is used to perform local disturbances on each transmission line in the target power grid based on the local-global information transmission chain, and to determine the sensitivity of the line impedance of each transmission line to the generalized short-circuit ratio based on the local disturbance results. The second construction unit is used to construct a power grid topology model of the target power grid and determine the electrical distance between power grid nodes and DC grid connection points based on the power grid topology model. In this model, substations in the target power grid are used as nodes in the power grid topology model, transmission lines between two substations are used as edges between corresponding nodes in the power grid topology model, and the line impedance of the transmission lines is used as the weight of the edges between corresponding nodes in the power grid topology model. An identification unit is used to identify the risk area of ​​the target power grid based on the sensitivity and the electrical distance.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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