A coordinated simulation modeling method for provincial power grid and local station

Abstract

This invention discloses a collaborative simulation modeling method for provincial power grids and local substations, relating to the fields of power system simulation and relay protection technology. The method includes: obtaining a full-scale detailed model of the provincial power grid; retaining the detailed structure of the target substation and its surrounding adjacent topology, and using the Thevenin equivalent method to equate the remaining parts of the full-scale detailed model to construct a simplified model of the provincial power grid; encapsulating the primary equipment and secondary protection devices within the target substation into a substation model that exposes only electrical and control interfaces; connecting the modular substation model to the simplified model through the electrical and control interfaces, replacing the target substation, and forming a co-simulation model; and setting up simulation tests with multiple types of fault scenarios on the co-simulation model to verify the collaborative characteristics between multiple sets of secondary protection devices. This invention improves computational efficiency through model simplification, improves integration efficiency through standardized encapsulation and interface design, and improves verification efficiency through co-simulation.

Description

Technical Field

[0001] This invention relates to the field of power system simulation and relay protection technology, specifically to a collaborative simulation modeling method for provincial power grids and local substations. Background Technology

[0002] As the "dual-high" characteristics (high proportion of renewable energy and high proportion of power electronic equipment) of the new power system continue to deepen, the transient processes of the power grid are becoming increasingly complex, and relay protection systems face severe challenges such as variations in fault characteristics and hidden potential risks. Existing technical solutions have the following limitations when addressing the joint simulation requirements of provincial power grids and local substations:

[0003] 1. The contradiction between model size and computational efficiency is prominent, making it difficult to support rapid engineering simulations.

[0004] Existing technologies often employ full-scale detailed modeling, resulting in low efficiency for rapid simulation and analysis of multiple scenarios and faults, making it difficult to meet the timeliness requirements of engineering applications. If simple equivalence or simplification is used, it cannot accurately reflect the dynamic electrical support characteristics of the main network to local areas, causing simulation accuracy distortion and falling into the technical dilemma of "accuracy and efficiency cannot be achieved simultaneously."

[0005] 2. Model integration relies on manual assembly and lacks interfaces and encapsulation methods.

[0006] Provincial power grid models and station-level primary and secondary detailed models belong to different modeling systems and lack unified interface specifications and encapsulation standards. Integrating station models into the provincial grid model requires manual topology analysis, boundary node matching, and parameter docking, which is not only time-consuming and labor-intensive but also prone to errors due to inconsistent interface definitions and node naming conflicts. Furthermore, the lack of model encapsulation methods makes it difficult to quickly deploy station models as reusable modules in different provincial grid scenarios, resulting in poor model integration efficiency and compatibility.

[0007] 3. Protection verification is limited to module-level testing and lacks a system-wide integrated verification solution.

[0008] Existing relay protection verification focuses on single protection devices, making it difficult to comprehensively evaluate the coordination characteristics between multiple protection devices (such as main protection and backup protection), between protection and circuit breakers, and between protection systems in different sites. It also fails to accurately reproduce the timing and logical coordination of the entire fault process, resulting in a fragmented understanding of the overall operating behavior of the protection system.

[0009] In summary, existing joint simulations of provincial power grids and local power stations suffer from low computational efficiency, low integration efficiency, and low verification efficiency. Summary of the Invention

[0010] The technical problem to be solved by this invention is the low efficiency of existing joint simulation of provincial power grids and local power stations. The purpose is to provide a collaborative simulation modeling method for provincial power grids and local power stations, which solves the above-mentioned problem.

[0011] This invention is achieved through the following technical solution:

[0012] In a first aspect, the present invention provides a collaborative simulation modeling method for provincial power grids and local power stations, comprising:

[0013] Obtain a full-scale detailed model of the provincial power grid;

[0014] The detailed structure of the target power station and its surrounding adjacent topology in the full-scale detailed model is retained, and the remaining peripheral power grids in the full-scale detailed model are equivalentd using the Thevenin equivalent method to construct a simplified model of the provincial power grid.

[0015] Construct detailed primary and secondary protection models of the target site, including primary equipment and secondary protection devices;

[0016] The station-level primary and secondary detailed models are encapsulated into station models that only expose electrical and control interfaces;

[0017] The station model is connected to the simplified model through the electrical interface and the control interface, replacing the target station to form a joint simulation model;

[0018] Multiple fault scenarios were set up on the joint simulation model for simulation testing to verify the collaborative characteristics among multiple secondary protection devices in the target site.

[0019] Optionally, the detailed structure of the target power station and its surrounding adjacent topology in the full-scale detailed model is retained, and the remaining peripheral power grids in the full-scale detailed model are dynamically equivalentd using the Thevenin equivalent method to construct a simplified model of the provincial power grid, including:

[0020] With the target station as the core, the adjacent nodes and branches are expanded outward layer by layer, and the entire detailed structure of the adjacent topology up to the Nth layer is retained as the core area;

[0021] Using the boundary nodes of the core area as ports, the peripheral power grid is subjected to Thevenin equivalent transformation to obtain a multi-port Thevenin equivalent circuit.

[0022] By connecting the multi-port Thevenin equivalent circuit to the boundary node of the core area, a simplified model of the provincial power grid is constructed.

[0023] Optionally, the step of performing a Thevenin equivalent transformation on the peripheral power grid using the boundary nodes of the core region as ports to obtain a multi-port Thevenin equivalent circuit includes:

[0024] Establish node voltage equations that include the core region and the peripheral power grid;

[0025] When the peripheral power grid does not contain a power source, the external nodes in the peripheral power grid are eliminated to obtain the equivalent admittance matrix of the boundary node, and a multi-port Thevenin equivalent circuit is constructed.

[0026] Optionally, after establishing the node voltage equations encompassing the core region and the peripheral power grid, the method further includes:

[0027] When the peripheral power grid includes a power source, the equivalent admittance matrix and equivalent current source of the boundary node are obtained by solving the node voltage equation;

[0028] The inverse of the equivalent admittance matrix is ​​used as the equivalent impedance matrix;

[0029] The product of the equivalent impedance matrix and the equivalent current source is used as the open-circuit voltage phasor;

[0030] A multi-port Thevenin equivalent circuit is constructed based on the equivalent impedance matrix and the open-circuit voltage phasor.

[0031] Optionally, after constructing a simplified model of the provincial power grid, the method further includes:

[0032] Obtain the electrical quantities at key nodes in the full-scale detailed model and the simplified model, respectively;

[0033] Calculate the error between the electrical quantities of the full-scale detailed model and the simplified model at the key node, and determine whether the error is greater than or equal to a preset error threshold;

[0034] If so, the number of layers in the adjacency topology is increased, and the simplified model is reconstructed until the error is less than the preset error threshold.

[0035] Optionally, calculating the error between the electrical quantities of the full-scale detailed model and the simplified model at the critical node, and determining whether the error is greater than or equal to a preset error threshold, includes:

[0036] If there are multiple key nodes, the error between the electrical quantities of the full-scale detailed model and the simplified model at the multiple key nodes is calculated to obtain multiple errors;

[0037] Based on the hierarchy of each key node in the core area, a preset weight coefficient is determined;

[0038] Calculate the weighted average of the multiple errors based on the weight coefficients of the key nodes;

[0039] Determine whether the weighted average of the multiple errors is greater than or equal to a preset error threshold.

[0040] Optionally, the encapsulation of the station-level primary and secondary detailed models into a station model that only exposes electrical and control interfaces includes:

[0041] A topology analysis is performed on both sides of the model to extract the common interface node set; the two sides of the model include the simplified model and the station-level first and second detailed models.

[0042] Record the correspondence, voltage level, and reference value of each common interface node in the common interface node set in the two side models to form an interface mapping table;

[0043] Based on the interface mapping table, design the electrical interface and the control interface;

[0044] The primary and secondary detailed models at the site level are encapsulated into a site model that exposes only the electrical interface and the control interface to the outside world.

[0045] Optionally, the step of performing topology analysis on both sides of the model and extracting the common interface node set includes:

[0046] Extract the set of boundary nodes directly connected to the target station from the simplified model, as well as the set of external connection ports from the station-level first and second detailed models;

[0047] Based on node name, voltage level, and topology association, the boundary node set is matched with the external connection port set to determine the candidate interface node set;

[0048] Nodes in the candidate interface node set that satisfy the continuity and consistency conditions are included in the common interface node set; wherein, the continuity condition is that the voltage is equal and the current is continuous in the two side models, and the consistency condition is that the reference voltage and reference power are consistent in the two side models.

[0049] Optionally, the design of electrical interfaces and control interfaces based on the interface mapping table includes:

[0050] Based on the interface mapping table, electrical pins are set for each common interface node to form an electrical interface; the attributes of the electrical pins include name, voltage level, dimension, and data type; the electrical interface is used for power exchange between the simplified model and the station model;

[0051] Based on the interface mapping table, virtual pins or global variables are used to map logic signals to form a control interface; the logic signals include trip commands, reclosing signals, circuit breaker status, and external blocking signals; the control interface is used for logic signal interaction between the simplified model and the station model.

[0052] Optionally, the step of setting up multiple types of fault scenarios on the joint simulation model for simulation testing to verify the collaborative characteristics among multiple sets of secondary protection devices in the target site includes:

[0053] An electromagnetic transient simulation engine is used, and the simulation step size and total simulation duration are set.

[0054] Simulation tests were conducted by setting up three types of fault scenarios: line fault, bus fault, and transformer fault. The timing of the full-process operation of multiple secondary protection devices in the target site under various fault conditions was recorded.

[0055] By comparing the timing of the entire process with the expected protection settings, the synergistic characteristics among the multiple sets of secondary protection devices are verified.

[0056] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0057] First, regarding computational efficiency, by preserving the detailed structure of the target power station and its surrounding adjacent topology, the remaining parts of the full-scale detailed model are equivalentd using the Thevenin equivalent method. This compresses the scale of provincial power grid nodes from hundreds or thousands to the core area scale, resulting in a significant reduction in computational load. Simultaneously, the Thevenin equivalent circuit accurately reflects the electrical support characteristics of the main grid for local areas, significantly improving the efficiency of rapid simulation of multiple scenarios and faults while ensuring the simulation accuracy of the target power station and its surroundings. Second, regarding integration efficiency, by encapsulating the primary equipment and secondary protection devices within the target power station into a power station model that exposes only standardized electrical and control interfaces, a unified interaction standard between the provincial grid side and the power station side is achieved, eliminating inconsistencies in interface definitions. The power station model automatically connects to the simplified model through standardized interfaces and replaces the original target power station, replacing the manual topology analysis, boundary matching, and parameter docking required in traditional methods, thus greatly improving integration efficiency. Finally, in terms of verification efficiency, the station model and the simplified model are integrated to form a joint simulation model, and multiple types of fault scenarios are set up for simulation testing. The collaborative characteristics of multiple secondary protection devices such as line protection, bus protection, and transformer protection can be verified in one go, thereby improving verification efficiency. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0059] Figure 1A flowchart illustrating a collaborative simulation modeling method for provincial power grids and local power stations provided in this application embodiment;

[0060] Figure 2 Example diagram of pin definitions for the electrical interface provided in the embodiments of this application;

[0061] Figure 3 This is another flowchart illustrating the collaborative simulation modeling method for provincial power grids and local power stations provided in this application embodiment. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0063] Please refer to Figure 1 This is a flowchart illustrating a collaborative simulation modeling method for provincial power grids and local power stations provided in this application embodiment. The following is a further explanation. Figure 1 The collaborative simulation modeling method for provincial power grids and local power stations is introduced.

[0064] S1. Obtain a full-scale detailed model of the provincial power grid.

[0065] In the specific implementation process, a full-scale detailed model of the provincial power grid is obtained from the dispatch automation system or offline simulation platform. This model contains the complete topology and detailed parameters of all nodes, branches, generators and loads within the province.

[0066] S2. Retain the detailed structure of the target station and its surrounding adjacent topology in the full-scale detailed model, and use the Thevenin equivalent method to perform equivalence on the remaining peripheral power grids in the full-scale detailed model to construct a simplified model of the provincial power grid.

[0067] S3. Construct detailed primary and secondary protection models of the target site, including primary equipment and secondary protection devices.

[0068] In the specific implementation process, based on the actual electrical main wiring diagram of the target site, the topological connection relationship between primary equipment such as busbars, transformers, lines and circuit breakers is established. On this basis, secondary protection devices such as line protection, transformer protection and bus differential protection are configured, and the secondary protection devices are associated with the corresponding primary equipment. The logical control relationship between the secondary protection devices and the primary equipment is established, thereby constructing a detailed primary and secondary model of the site that includes primary equipment and secondary protection devices.

[0069] S4. Encapsulate the primary and secondary detailed models of the site into a site model that only exposes electrical and control interfaces.

[0070] S5. By connecting the station model to the simplified model through the electrical and control interfaces, the target station is replaced to form a joint simulation model.

[0071] In the implementation process, the original primary equipment topology of the target power station was removed from the simplified model. The power station model was connected to the boundary nodes through electrical interfaces, and a signal mapping relationship was established between the control interface and the simplified model to form a unified co-simulation model. The co-simulation model retains the dynamic support characteristics of the provincial power grid to the external power grid, and also includes detailed primary equipment topology and secondary protection device logic within the power station, laying the model foundation for subsequent verification of protection coordination characteristics under various fault scenarios.

[0072] S6. Simulate and test multiple types of fault scenarios on the joint simulation model to verify the collaborative characteristics between multiple secondary protection devices in the target site.

[0073] In this embodiment, addressing the three major problems of low computational efficiency, low integration efficiency, and low verification efficiency in existing joint simulations of provincial power grids and local substations, this invention integrates model construction, simplified equivalence, interface integration, and simulation verification through a complete technical chain of "model simplification—standardized encapsulation—interface access—joint verification." This eliminates manual data transfer and process connection between different stages, achieving full automation from model preparation to protection system evaluation. It provides efficient, systematic, and engineering-applicable closed-loop technical support for power grid protection operation, effectively improving the intelligence level and proactive defense capabilities of power grid operation management.

[0074] In one possible embodiment, step S2 includes:

[0075] Taking the target power station as the core, the adjacent nodes and branches are expanded outward layer by layer, and the complete detailed structure of the adjacent topology up to the Nth layer is retained as the core area; taking the boundary nodes of the core area as ports, the Thevenin equivalent transformation is performed on the peripheral power grid to obtain the multi-port Thevenin equivalent circuit; the multi-port Thevenin equivalent circuit is connected to the boundary nodes of the core area to construct a simplified model of the provincial power grid.

[0076] In the specific implementation process, a hierarchical adjacency topology preservation strategy is adopted: taking the target site to be spliced ​​as the core, the adjacent nodes and branches are expanded outward layer by layer, and the entire detailed structure of the adjacency topology up to the Nth layer is preserved as the core area. Here, N is the number of layers of the adjacency topology, and the value of N can be dynamically determined according to the upper limit of the target node size, which depends on the computing power of the simulation platform.

[0077] The boundary nodes of the core region refer to the outermost nodes of the core region, that is, the nodes in the Nth layer of the adjacency topology that are directly connected to the external power grid. Using the boundary nodes of the core region as ports, the peripheral power grid outside the core region is dynamically equivalentd using the Thevenin equivalent method to obtain a multi-port Thevenin equivalent circuit.

[0078] From the perspective of power system analysis theory, the dynamic equivalent problem of large-scale power grids can be described as follows: for the internal network under study (i.e., the target power station and its surrounding core area where detailed structure needs to be preserved), the dynamic response characteristics of its external network (i.e., the peripheral power grid) to the core area can be characterized through an equivalent network. This embodiment uses Thevenin's equivalent theorem as its theoretical basis, that is, under power frequency conditions, looking from the boundary node k of the core area towards the external power grid, the entire peripheral power grid can be equivalently represented as an ideal voltage source. With equivalent impedance The mathematical expression for the series form of is:

[0079] (1.1)

[0080] For a multi-port system, with the boundary node set B = {1,2,…,m} preserved, the port characteristics of the external power grid can be described by the following system of linear algebraic equations:

[0081] (1.2)

[0082] In the formula, and These are the voltage phasor and injected current phasor at the boundary node k, respectively; It is self-impedance. ( () represents the mutual impedance. This equivalent parameter reflects the electrical support strength and coupling relationship of the external power grid to the core area under different operating modes.

[0083] In this embodiment, a simplification strategy of "refined modeling of the core area + dynamic equivalence of the periphery" is adopted to significantly reduce the model size while ensuring the fidelity of key dynamic characteristics of the local power grid, thereby resolving the contradiction between the large scale of the provincial power grid and the efficiency of simulation calculation.

[0084] In one possible embodiment, the step of performing a Thevenin equivalent transformation on the peripheral power grid using the boundary nodes of the core region as ports to obtain a multi-port Thevenin equivalent circuit includes:

[0085] Establish node voltage equations that include the core area and the peripheral power grid;

[0086] When the external power grid does not contain power sources, the external nodes in the external power grid are eliminated to obtain the equivalent admittance matrix of the boundary nodes, and a multi-port Thevenin equivalent circuit is constructed.

[0087] When the external power grid includes power sources, the equivalent admittance matrix and equivalent current source of the boundary node are obtained by solving the node voltage equation; the inverse matrix of the equivalent admittance matrix is ​​used as the equivalent impedance matrix; the product of the equivalent impedance matrix and the equivalent current source is used as the open-circuit voltage phasor; and a multi-port Thevenin equivalent circuit is constructed based on the equivalent impedance matrix and the open-circuit voltage phasor.

[0088] In the specific implementation process, let the set of internal nodes of the core area be denoted as . The set of boundary nodes is The calculation process for the equivalent parameters of the external power grid is as follows:

[0089] For a linear network, viewed from a set of boundary ports, the entire peripheral power grid can be represented by a multi-port Thevenin equivalent circuit: each port contains a series ideal voltage source and an equivalent impedance, and there is mutual impedance coupling between the ports. This equivalent is accurate under steady-state conditions at power frequency and can approximately reflect the dynamic characteristics of the peripheral power grid within a certain bandwidth.

[0090] Establish the node voltage equations for the entire network (in phasor form):

[0091] (1.3)

[0092] Among them, subscript This represents internal nodes (nodes within the core area excluding boundary nodes). Represents the boundary nodes of the core area. This represents an external node (a node in the external power grid, the part that will be replaced by an equivalent value). This is the admittance submatrix for the corresponding block. For node voltage phasors, Inject current phasors into nodes (typically, the injected current into internal and external nodes is zero unless there is a power source or load; however, loads can be treated as ground admittances in Y).

[0093] Then the equation related to the external nodes in equation (1.3) is:

[0094] (1.4)

[0095] Therefore, the external node voltage can be solved in terms of boundary nodes:

[0096] (1.5)

[0097] Substituting equation (1.5) into the equations related to the boundary nodes:

[0098] (1.6)

[0099] Meanwhile, the equations for the internal nodes are:

[0100] (1.7)

[0101] From equation (1.7), we get Substituting into equation (1.6):

[0102] (1.8)

[0103] Define the simplified boundary node admittance matrix:

[0104] (1.9)

[0105] In fact, if the internal nodes also retain a detailed model (i.e., the I-region is not simplified), then the internal nodes should not be eliminated, but their detailed structure should be preserved. The term should not appear. A more reasonable approach is to only perform equivalent calculations on the outer power grid, while retaining the entire core region. Therefore, the boundary node equations should only include the eliminated influence of the outer power grid, while the internal nodes are retained in the model for detailed calculations. In co-simulation, the core region is directly connected to the boundary nodes and does not need to be eliminated. Therefore, the correct approach is to retain all nodes in the core region and eliminate only the outer node E. Then, looking in from the boundary nodes, the equivalent admittance matrix is ​​contributed only by the outer power grid:

[0106] (1.10)

[0107] Furthermore, the boundary nodes are connected to the core region, and the admittance of the core region is already reflected in the detailed model. Therefore, the simplified whole-network equation can be written as:

[0108] (1.11)

[0109] in This includes the current injected from the boundary nodes (including contributions from the equivalent network of the external power grid and the core region). In fact, the contribution of the equivalent network of the external power grid to the boundary nodes has been modified by adjusting the admittance matrix. The manifestation, and the injected current term The influence of external power sources should also be considered.

[0110] When the external power grid contains power sources such as generators, simply eliminating nodes will result in the loss of power source information. In this case, Thevenin's equivalent is needed: the external power grid is equivalent to the series impedance of voltage sources on the boundary nodes. The derivation process is as follows:

[0111] Reconsidering the external power grid, its node voltage equations include source injection currents. Treating the external power grid as an independent subsystem, the boundary node voltages... As an excitation, current is injected into the external node. Given (the power source model can be treated as a current source), the external network equations can be solved using equation (1.4):

[0112] (1.12)

[0113] The injected current (flowing into the boundary from the external network) at the boundary node is:

[0114] (1.13)

[0115] The above formula can be rewritten as:

[0116] (1.14)

[0117] in: It is the equivalent admittance matrix; Let be the short-circuit current at the boundary nodes (the injection current provided by the external power supply when all boundary nodes are short-circuited). From equation (1.14), the Norton equivalent circuit viewed from the boundary nodes can be obtained: equivalent admittance matrix. Equivalent current source .

[0118] Convert to Thevenin form:

[0119] (1.15)

[0120] in, , This is the open-circuit voltage phasor.

[0121] Therefore, for cases with multiple boundary nodes, the external power grid can be replaced by a linear multiport network, whose port characteristics are described by equation (1.14) or the corresponding Thevenin form. In actual simulations, the equivalent network of this external power grid can be used as a "black box" model connected to the boundary nodes of the core area, which preserves the electrical support characteristics of the external power grid while significantly reducing the number of computational nodes.

[0122] In one possible embodiment, after constructing a simplified model of the provincial power grid, the electrical quantities at key nodes of the full-scale detailed model and the simplified model are obtained respectively; the error between the electrical quantities at key nodes of the full-scale detailed model and the simplified model is calculated, and it is determined whether the error is greater than or equal to a preset error threshold; if so, the number of layers of the adjacent topology is increased, and the simplified model is reconstructed until the error is less than the preset error threshold.

[0123] In practical implementation, key nodes can be boundary nodes or internal nodes. Electrical quantities can be voltage, current, etc. Taking voltage as an example, the following relative error formula can be used:

[0124] (1.16)

[0125] in, This represents the voltage magnitude at a specific node in the full-scale detailed model. This represents the voltage magnitude at the same node in the simplified model; This represents the error between the voltage magnitudes of the two models at the same node.

[0126] If there is only one critical node, the error between the electrical quantities of the full-scale detailed model and the simplified model at that node is directly calculated, and it is determined whether it is greater than or equal to the preset error threshold.

[0127] If there are multiple critical nodes, calculate the error between the electrical quantities of the full-scale detailed model and the simplified model at the multiple critical nodes to obtain multiple errors; preset weight coefficients according to the hierarchy of each critical node in the core area; calculate the weighted average of the multiple errors according to the weight coefficients of the critical nodes; and determine whether the weighted average of the multiple errors is greater than or equal to the preset error threshold.

[0128] If the error is less than the preset error threshold, it means that the accuracy of the simplified model meets the requirements, and the current simplified model is retained; if it is greater than or equal to the preset error threshold, it means that the accuracy of the simplified model does not meet the requirements, and the number of adjacent layers N is increased (let N=N+1), and the simplified model is reconstructed until the accuracy meets the requirements.

[0129] Weighting coefficients are preset based on the hierarchy of each key node in the core area; the closer the hierarchy is to the target site, the higher the weighting coefficient, reflecting its importance to the simulation accuracy.

[0130] For example, in the core area, layer 0 is the complete detailed structure inside the target site (busbars, transformers, circuit breakers, lines, etc.), layer 1 is the transmission lines directly connected to the target site and the substation on the opposite side, layer 2 is the lines directly connected to the substation in layer 1 and the substation further away, and layer N is the boundary nodes.

[0131] If the key node is at level 0, the corresponding weight coefficient is 1.0; if the key node is at level 1, the corresponding weight coefficient is 0.9; if the key node is at level 2, the corresponding weight coefficient is 0.8.

[0132] The preset error thresholds can be determined according to the engineering application scenario. For example, in the steady-state power flow analysis scenario, the voltage error threshold is 0.5% and the current error threshold is 1%; in the transient stability analysis scenario, the voltage error threshold is 1% and the current error threshold is 2%; in the protection setting verification scenario, the voltage error threshold is 0.5% and the current error threshold is 1%; in the engineering rapid simulation scenario, the voltage error threshold is 2% and the current error threshold is 3%.

[0133] In this embodiment, a full-scale detailed model is used as a benchmark. Electrical quantities such as voltage and current at the same node are selected for comparative testing to verify the dynamic response fidelity of the simplified model, ensuring that errors are controlled within an acceptable engineering range and laying the model foundation for subsequent efficient collaborative simulation. By setting hierarchical weight coefficients, the closer the layer is to the target site, the higher the weight, reflecting the difference in node importance and making the evaluation results more consistent with engineering reality. Simultaneously, by dynamically adjusting the number of adjacent layers N, a balance can be achieved between accuracy and efficiency, avoiding insufficient accuracy due to oversimplification and inefficiency due to excessive retention.

[0134] In one possible embodiment, step S4 includes:

[0135] Topology analysis is performed on both sides of the model to extract the common interface node set. The two sides of the model include a simplified model and a station-level primary and secondary detailed model. The correspondence, voltage level and reference value of each common interface node in the common interface node set in the two sides of the model are recorded to form an interface mapping table. Based on the interface mapping table, electrical interfaces and control interfaces are designed. The station-level primary and secondary detailed models are encapsulated into a station model that only exposes electrical interfaces and control interfaces to the outside.

[0136] In practical implementation, from a graph theory perspective, the power grid can be abstracted as an undirected graph G=(V,E), where the vertex set V represents electrical points such as buses, and the edge set E represents transmission lines, transformer branches, etc. A simplified model of the provincial power grid is denoted as... The detailed primary and secondary models of the station are denoted as follows: When the two are to be joined, there exists a common set of vertices. ∩ These vertices are the same physical electrical nodes (such as the common electrical bus between the target site and the power grid model). Based on the common vertex set, the correspondence, voltage level, reference value, and other information of each interface node in the models on both sides are recorded to form an interface mapping table.

[0137] The primary and secondary detailed models of the power station are encapsulated into a single model that exposes only electrical and control interfaces. This encapsulation process involves two steps: graphical design and parameter configuration. The graphical design creates the top-level symbol of the power station model, exposing only essential electrical and control pins while concealing the complex internal topology. Symbol design follows a modular principle: electrical pins are placed at symbol boundaries, grouped by voltage level, and labeled with pin names; control pins are typically arranged as ports with clear classifications (e.g., trip output, status input). Completed symbols can be dragged and dropped directly into the main canvas of the provincial grid model and connected to the provincial grid boundary nodes via lines to achieve physical connectivity. In the parameter configuration phase, users need to set specific parameters for each component within the encapsulated model, such as transformer capacity, short-circuit impedance, protection settings, and circuit breaker operating time. These parameters are presented in tabular form for easy batch modification and verification.

[0138] In this embodiment, by extracting a set of common interface nodes and forming an interface mapping table, a complex field station model containing primary equipment and secondary protection devices is encapsulated into a field station model that exposes only standardized electrical and control interfaces. The encapsulated field station model possesses "black box" characteristics; its internal topology is hidden, and only necessary pins are exposed externally, significantly reducing the complexity of model usage. Simultaneously, the parameters are presented in tabular form, facilitating batch modification and verification, thus improving the model's maintainability and reusability. This standardized encapsulation method provides technical support for the rapid deployment of field station models in different provincial network scenarios, achieving "plug-and-play" functionality.

[0139] In one possible embodiment, the steps of performing topology analysis on both sides of the model and extracting the common interface node set include:

[0140] Extract the set of boundary nodes directly connected to the target station from the simplified model, as well as the set of external connection ports from the station-level primary and secondary detailed models; match the boundary node set and the external connection port set according to node name, voltage level, and topological association to determine the candidate interface node set; include the nodes in the candidate interface node set that meet the continuity and consistency conditions into the common interface node set; wherein, the continuity condition is that the voltage is equal and the current is continuous in both models, and the consistency condition is that the reference voltage and reference power are consistent in both models.

[0141] In practical implementation, to achieve automated extraction, methods based on node naming conventions or electrical distance matching can be adopted. First, a topology traversal is performed on a simplified model of the provincial power grid to identify the set of boundary nodes directly connected to the target power station. Simultaneously, the set of external connection ports is extracted from the primary and secondary detailed models of the station. By matching and Based on the node names, voltage levels, and topological relationships, determine the candidate interface node set. .

[0142] Verify whether the nodes in the candidate interface node set satisfy the continuity and consistency conditions. Assume that in the simplified model, the interface nodes... The voltage phasor is The injected current is Interface nodes in the primary and secondary detailed models at the station level The voltage phasor is The injected current is According to Kirchhoff's laws, the following continuity condition must be satisfied:

[0143] (1.17)

[0144] If the interface node It also satisfies the consistency condition: the two models at the interface node If the reference voltage and reference power are consistent, then the interface node will be... Include it in the public interface node set.

[0145] In this embodiment, the above-described topology analysis and common interface extraction method can automatically identify the electrical connection boundaries between the simplified model of the provincial power grid and the primary and secondary detailed models at the station level, forming an accurate interface mapping relationship. Verification of the electrical interface continuity condition ensures that Kirchhoff's laws are satisfied after splicing, ensuring the accurate transmission of electrical boundary conditions. Verification of the parameter consistency condition ensures that electrical quantities are transmitted under the same reference, laying a solid foundation for subsequent interface design.

[0146] In one possible embodiment, the steps of designing electrical interfaces and control interfaces based on an interface mapping table include:

[0147] Based on the interface mapping table, electrical pins are set for each common interface node to form an electrical interface; the attributes of the electrical pins include name, voltage level, dimension and data type; the electrical interface is used to simplify power exchange between the model and the site model;

[0148] Based on the interface mapping table, virtual pins or global variables are used to map logic signals to form a control interface; the logic signals include trip commands, reclosing signals, circuit breaker status, and external blocking signals; the control interface is used to simplify the interaction of logic signals between the model and the site model.

[0149] In practical implementation, the electrical interface defines the ports for power exchange between the simplified model and the site model. In simulation tools, this is typically achieved by defining "pins." Each common interface node corresponds to one electrical pin. Electrical interface design must adhere to standardization principles, such as using unified pin naming rules and data types (complex numbers or instantaneous values), to support model exchange between different simulation platforms. Figure 2 This is an example diagram of the pin definition of the electrical interface provided in the embodiments of this application, wherein each pin corresponds to the sender or receiver of an actual line.

[0150] From a signal flow perspective, the control interface can be modeled as a hybrid interface of discrete-time and continuous-time systems. Let the protection device output a set of logic signals. Examples include "phase A jump" and "successful overlap"; input signal set Such signals include circuit breaker position and external interlocking signals. These signals need to be mapped through control pins.

[0151] In simulation environments, control interfaces are typically implemented using virtual pins or global variables. During the design phase, the physical meaning, logic level (e.g., 0 / 1), triggering method (rising edge / level), and propagation delay of each signal must be clearly defined.

[0152] Taking the line trip signal as an example, after the station protection device detects a fault, it issues a trip command after a short delay. This command is simultaneously sent to the line protection device inside the station, which first trips the corresponding circuit breaker in the station, and then transmits it to the control model of the corresponding circuit breaker on the provincial grid side through the control interface, triggering the circuit breakers on both sides of the protected line to open.

[0153] To ensure accurate timing, the interface design must consider the signal transmission delay τ and establish a signal transfer function:

[0154] (1.18)

[0155] Where x(t) is the command signal from the transmitting end, y(t) is the command signal from the receiving end, and τ is the signal transmission delay time. In practice, a fixed delay can be set or dynamically calculated by the communication model.

[0156] In addition, the control interface must support coordinated signals between multiple protection devices, such as "three-way trip" and "failure start". These signals need to be pre-planned in the interface definition to ensure that the models on both sides can correctly parse them. For example, when the circuit breaker failure protection operates, a "failure start" signal is issued and transmitted to the adjacent protection device through the control interface, triggering the adjacent circuit breaker to trip.

[0157] In this embodiment, the simplified communication between the simplified model and the site model is achieved through the aforementioned electrical and control interface designs. The electrical interface adopts unified pin definitions and standardization principles, supporting model exchange between different simulation platforms. The control interface uses virtual pins or global variables for signal mapping, clearly defining the transmission methods of logical signals such as trip commands, reclosing signals, and circuit breaker status. It also introduces transmission delay parameters to simulate the timing characteristics in actual communication and supports coordinated signals between multiple protection devices. This standardized interface design lays a solid foundation for subsequent joint simulation verification.

[0158] In one possible embodiment, step S6 includes:

[0159] An electromagnetic transient simulation engine was used to set the simulation step size and total simulation time. Three types of fault scenarios, namely line fault, bus fault and transformer fault, were set up for simulation testing. The full-process action sequence of multiple secondary protection devices in the target site under various faults was recorded. By comparing the full-process action sequence with the expected protection settings, the coordination characteristics between multiple secondary protection devices were verified.

[0160] In the specific implementation process, the simulation environment adopts an electromagnetic transient simulation engine, the simulation step size is set to ΔT (typical value 50μs), and the total simulation time is... (Typical value 10s) This system can accurately capture the transient process of a fault and the timing of the protective device's actions. The system side adopts the full wiring configuration of the target substation (such as a core substation), including the main wiring for the specified voltage level, and all protective devices (including line protection, busbar protection, transformer protection, and circuit breaker protection) are activated. Fault scenarios should cover line faults, busbar faults, and transformer faults. Typical parameters are set for each type of fault to verify the selectivity, speed, reliability, sensitivity, and coordination capabilities of the protection system.

[0161] First scenario: Line fault verification:

[0162] Select a voltage level between the target power station and adjacent power stations. A typical line is used as the test object. A single-phase (or phase-to-phase) permanent ground fault is set, with the fault point located at x% (e.g., 50%) of the total line length. The transition resistance... (Typical value 0.1 Ω), Fault onset time This process continues until the simulation ends (or is set as a permanent fault). This scenario aims to verify the complete operation of the main line protection, backup protection, reclosing, and permanent fault discrimination logic.

[0163] The simulation should reproduce the complete protection action sequence, including fault initiation, main protection action, circuit breaker tripping, reclosing, and permanent fault re-tripping. Table 1 provides typical action sequence examples for permanent line faults (the specific timing depends on the protection settings and system parameters). The fault start time. This refers to the differential protection operating time. This refers to the circuit breaker tripping time. This refers to the reclosing time; This refers to the secondary action time of the differential protection. This refers to the secondary tripping time of the circuit breaker.

[0164] Table 1. Typical action timing examples of permanent line faults

[0165]

[0166] By comparing the actual action sequence with the protection settings, the selectivity (only tripping the faulty phase), speed (main protection action time), reliability (correct identification of permanent faults), and correctness of the reclosing logic of the line protection can be verified.

[0167] Second scenario, bus fault verification:

[0168] Imagine a three-phase permanent short-circuit fault occurring on a busbar (such as a section of a double busbar connection) at a certain voltage level in a target substation. The transition resistance... Smaller (typical value 0.1 Ω), fault onset time The simulation continues until its end. This scenario aims to verify the rapid discrimination capability of the bus differential protection, the circuit breaker tripping and isolation action, and the delayed coordination of the backup protection on the opposite side.

[0169] The simulation should record the busbar protection operating time, circuit breaker tripping sequence, and the response of the protection on the opposite side of adjacent lines. Table 2 provides a typical example of the operating sequence for a busbar fault. The fault start time. For the timing of the differential protection action; This refers to the circuit breaker tripping time. This is the time for backup protection actions.

[0170] Table 2 Example of Busbar Permanent Fault Protection Action Sequence

[0171]

[0172] This process can be used to verify the selectivity and speed of the main bus protection, as well as the time-delay coordination logic of the backup protection, to ensure reliable isolation in the event of a bus fault, while avoiding cascading tripping.

[0173] Third scenario: Transformer fault verification:

[0174] Imagine a three-phase short-circuit fault occurring inside a main transformer (e.g., #2 main transformer) within the target site. The transition resistance... Smaller, fault start time The simulation continues until its end. This scenario aims to verify the speed of the transformer's main protection and the multiple confirmation mechanisms for faults by multiple protection systems (such as longitudinal differential instantaneous trip, sectional differential, incremental differential, etc.).

[0175] The simulation should record the main protection activation time, circuit breaker tripping sequence, and subsequent auxiliary protection activation. Table 3 provides a typical action sequence example for internal transformer faults. The fault start time. This refers to the transformer protection operating time. This refers to the circuit breaker tripping time. This is the time for backup protection actions.

[0176] Table 3. Example of the operating sequence of the three-phase short-circuit protection inside the transformer.

[0177]

[0178] By observing the starting sequence of the main protection and each auxiliary protection, the speed of transformer protection (fast action of the main protection) and reliability (confirmation by multiple criteria to prevent false tripping) can be verified.

[0179] Please refer to Figure 3 This is another flowchart illustrating the collaborative simulation modeling method for provincial power grids and local power stations provided in this application embodiment. First, provincial power grid monitoring is performed; second, detailed primary and secondary models at the power station level are integrated; and finally, joint simulation verification is conducted. Compared with existing technologies, this invention has the following significant advantages:

[0180] 1. Overcome the contradiction between accuracy and efficiency, and lay the foundation for efficient collaborative simulation.

[0181] This invention employs a power grid primary model simplification strategy of "refined modeling of the core area + dynamic equivalence of the periphery," achieving a significant reduction in model size while maintaining the fidelity of key dynamic characteristics of the local power grid. This theoretical framework can, to some extent, resolve the contradiction between the low efficiency of full-scale simulation and the accuracy distortion of simple equivalence, providing a high-fidelity and high-efficiency model foundation for efficient collaborative simulation of provincial power grids and local power plants, making rapid simulation and analysis of multiple scenarios and faults feasible in engineering.

[0182] 2. Establish a standardized integration system to enable plug-and-play and efficient reuse of models.

[0183] This invention constructs a standardized model splicing technology system encompassing "topology analysis—interface extraction—collaborative design—encapsulation and integration." By forming a complete public interface mapping, it ensures a one-to-one correspondence between provincial grid boundary nodes and substation outgoing ports; through the collaborative design of electrical and control interfaces, it achieves accurate mapping of power flow and information flow; and through the graphical encapsulation and parameter configuration of the substation model, it transforms a complex system containing primary equipment and secondary protection devices into reusable standardized modules. This technology system helps overcome the limitations of traditional model integration, which relies on manual splicing, suffers from chaotic interface definitions, and poor compatibility. It enables "plug-and-play" and efficient reuse of substation models in different provincial grid scenarios, thereby improving the construction efficiency and model consistency of the co-simulation platform.

[0184] 3. Break through the limitations of module-level verification and achieve a comprehensive evaluation of the collaborative characteristics of the whole-site protection system.

[0185] The co-simulation model constructed in this invention can perform integrated verification of multiple types of fault scenarios for the entire substation's primary and secondary integrated system, accurately reproducing the entire process of the protection device's action timing and logical coordination under line, bus, and transformer faults. In line faults, it can verify the complete action chain of differential main protection, distance backup protection, reclosing, and permanent fault discrimination logic; in bus faults, it can verify the rapid discrimination capability of the bus differential protection and the delayed coordination of the opposite backup protection; in transformer faults, it can verify the multiple confirmation mechanisms for faults by multiple sets of protections, including longitudinal differential instantaneous trip, side differential, and incremental differential. This substation-wide integrated verification capability overcomes the fragmented defects of traditional technologies limited to testing single protection devices or single functional modules, providing a highly reliable technical means for comprehensively evaluating the selectivity, speed, reliability, and coordination characteristics of the protection system.

[0186] 4. Support the joint operation analysis of the "three lines of defense" to form a complete technical closed loop from model to decision-making.

[0187] The collaborative simulation model constructed in this invention provides a high-fidelity verification environment for setting optimization, fault inversion, and new principle testing of the first line of defense (relay protection). Simultaneously, it lays a solid model and technical foundation for the collaborative simulation operation of the second line of defense (stability control) and the third line of defense (low-frequency, low-voltage load shedding, etc.). Through standardized model integration and multi-fault scenario verification, the platform can transform simulation analysis results into a systematic understanding of the operating behavior of the protection system, serving operational processes such as dispatching, protection setting, and fault analysis. This complete technical loop ultimately transforms the original models and data into intuitive insights and decision-making basis that can guide the safe operation of the power grid, significantly improving the intelligence level and proactive defense capabilities of power grid operation management, and helping to achieve a leap from passive response to proactive defense.

[0188] Based on the same inventive concept, this application also provides a collaborative simulation modeling system for provincial power grids and local power stations, the system comprising:

[0189] The acquisition module is used to acquire a full-scale detailed model of the provincial power grid;

[0190] The simplification module is used to retain the detailed structure of the target power station and its surrounding adjacent topology in the full-scale detailed model, and to use the Thevenin equivalent method to convert the remaining peripheral power grid in the full-scale detailed model into a simplified model of the provincial power grid.

[0191] The building module is used to build detailed primary and secondary models of the target site, including primary equipment and secondary protection devices.

[0192] The encapsulation module is used to encapsulate the primary and secondary detailed models of the site into a site model that only exposes the electrical and control interfaces;

[0193] The access module is used to connect the site model to the simplified model through electrical and control interfaces, replace the target site, and form a joint simulation model.

[0194] The simulation module is used to set up multiple types of fault scenarios on the co-simulation model for simulation testing, and to verify the coordination characteristics between multiple secondary protection devices in the target site.

[0195] Optionally, the simplified module is specifically used for:

[0196] With the target station as the core, the adjacent nodes and branches are expanded outward layer by layer, and the entire detailed structure of the adjacent topology up to the Nth layer is retained as the core area;

[0197] Using the boundary nodes of the core area as ports, the Thevenin equivalent transformation is performed on the peripheral power grid to obtain a multi-port Thevenin equivalent circuit;

[0198] By connecting multi-port Thevenin equivalent circuits to the boundary nodes of the core area, a simplified model of the provincial power grid is constructed.

[0199] Optionally, the simplified module is specifically used for:

[0200] Establish node voltage equations that include the core area and the peripheral power grid;

[0201] When the external power grid does not contain power sources, the external nodes in the external power grid are eliminated to obtain the equivalent admittance matrix of the boundary nodes, and a multi-port Thevenin equivalent circuit is constructed.

[0202] Optionally, after establishing the node voltage equations that include the core area and the peripheral power grid, the method further includes:

[0203] When the external power grid includes power sources, the equivalent admittance matrix and equivalent current source of the boundary node can be obtained by solving the node voltage equations.

[0204] The inverse of the equivalent admittance matrix is ​​used as the equivalent impedance matrix;

[0205] The product of the equivalent impedance matrix and the equivalent current source is used as the open-circuit voltage phasor.

[0206] A multi-port Thevenin equivalent circuit is constructed based on the equivalent impedance matrix and the open-circuit voltage phasor.

[0207] Optionally, the device further includes a verification module, which is used for:

[0208] After constructing a simplified model of the provincial power grid, the electrical quantities at key nodes of the full-scale detailed model and the simplified model are obtained respectively.

[0209] Calculate the error between the electrical quantities at key nodes in the full-scale detailed model and the simplified model, and determine whether the error is greater than or equal to a preset error threshold.

[0210] If so, increase the number of layers in the adjacency topology and rebuild the simplified model until the error is less than the preset error threshold.

[0211] Optionally, the verification module is specifically used for:

[0212] If there are multiple critical nodes, calculate the error between the electrical quantities of the full-scale detailed model and the simplified model at the multiple critical nodes to obtain multiple errors;

[0213] Based on the hierarchy of each key node in the core area, preset weight coefficients are used.

[0214] Calculate the weighted average of multiple errors based on the weight coefficients of the key nodes;

[0215] Determine whether the weighted average of multiple errors is greater than or equal to a preset error threshold.

[0216] Optionally, the encapsulation module is specifically used for:

[0217] Topological analysis was performed on both sides of the model to extract the common interface node set; the two sides of the model include a simplified model and a station-level first and second detailed model.

[0218] Record the correspondence, voltage level, and reference value of each common interface node in the common interface node set in the two side models to form an interface mapping table;

[0219] Design electrical and control interfaces based on the interface mapping table;

[0220] The primary and secondary detailed models at the station level are encapsulated into station models that only expose electrical and control interfaces to the outside world.

[0221] Optionally, the encapsulation module is specifically used for:

[0222] Extract the set of boundary nodes directly connected to the target station from the simplified model, as well as the set of external connection ports from the station-level primary and secondary detailed models;

[0223] Based on node name, voltage level and topology association, the set of boundary nodes and the set of external connection ports are matched to determine the set of candidate interface nodes;

[0224] Nodes that meet the continuity and consistency conditions in the candidate interface node set are included in the common interface node set. The continuity condition is that the voltage is equal and the current is continuous in both models, and the consistency condition is that the reference voltage and reference power are consistent in both models.

[0225] Optionally, the encapsulation module is specifically used for:

[0226] Based on the interface mapping table, electrical pins are set for each common interface node to form an electrical interface; the attributes of the electrical pins include name, voltage level, dimension and data type; the electrical interface is used to simplify power exchange between the model and the site model;

[0227] Based on the interface mapping table, virtual pins or global variables are used to map logic signals to form a control interface; the logic signals include trip commands, reclosing signals, circuit breaker status, and external blocking signals; the control interface is used to simplify the interaction of logic signals between the model and the site model.

[0228] Optionally, the simulation module is specifically used for:

[0229] An electromagnetic transient simulation engine is used, and the simulation step size and total simulation duration are set.

[0230] Simulation tests were conducted by setting up three types of fault scenarios: line fault, bus fault, and transformer fault. The timing of the actions of multiple secondary protection devices in the target site under various fault conditions was recorded.

[0231] By comparing the timing of the entire operation with the expected protection settings, the synergistic characteristics between multiple sets of secondary protection devices are verified.

[0232] It should be noted that each module in the collaborative simulation modeling system of provincial power grid and local power stations in this embodiment corresponds one-to-one with each step in the collaborative simulation modeling method of provincial power grid and local power stations in the aforementioned embodiment. Therefore, the specific implementation of this embodiment can refer to the implementation of the collaborative simulation modeling method of provincial power grid and local power stations mentioned above, and will not be repeated here.

[0233] Based on the same inventive concept, this application also provides a computer device, which includes a processor, a memory, and a computer program stored in the memory. The computer program is executed by the processor to implement the aforementioned collaborative simulation modeling method for provincial power grids and local power stations.

[0234] Based on the same inventive concept, this application also provides a computer storage medium storing a computer program, which is executed by a processor to implement the aforementioned collaborative simulation modeling method for provincial power grids and local power stations.

[0235] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a device including one or any combination of the above-mentioned memories. The computer may be a variety of computing devices, including smart terminals and servers.

[0236] In some embodiments, executable instructions may take the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0237] As an example, executable instructions may, but do not necessarily, correspond to files in the file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple collaborative files (e.g., a file that stores one or more modules, subroutines, or code sections).

[0238] As an example, executable instructions can be deployed to execute on a single computing device, or on multiple computing devices located in one location, or on multiple computing devices distributed across multiple locations and interconnected via a communication network.

[0239] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0240] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0241] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. 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 collaborative simulation modeling method for provincial power grids and local power stations, characterized in that, include: Obtain a full-scale detailed model of the provincial power grid; The detailed structure of the target power station and its surrounding adjacent topology in the full-scale detailed model is retained, and the remaining peripheral power grids in the full-scale detailed model are equivalentd using the Thevenin equivalent method to construct a simplified model of the provincial power grid. Construct detailed primary and secondary protection models of the target site, including primary equipment and secondary protection devices; The station-level primary and secondary detailed models are encapsulated into station models that only expose electrical and control interfaces; The station model is connected to the simplified model through the electrical interface and the control interface, replacing the target station to form a joint simulation model; Multiple fault scenarios were set up on the joint simulation model for simulation testing to verify the collaborative characteristics among multiple secondary protection devices in the target site.

2. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 1, characterized in that, The detailed structure of the target power station and its surrounding adjacent topology in the full-scale detailed model is retained. The remaining peripheral power grids in the full-scale detailed model are dynamically equivalent using the Thevenin equivalent method to construct a simplified model of the provincial power grid, including: With the target station as the core, the adjacent nodes and branches are expanded outward layer by layer, and the entire detailed structure of the adjacent topology up to the Nth layer is retained as the core area; Using the boundary nodes of the core area as ports, the peripheral power grid is subjected to Thevenin equivalent transformation to obtain a multi-port Thevenin equivalent circuit. By connecting the multi-port Thevenin equivalent circuit to the boundary node of the core area, a simplified model of the provincial power grid is constructed.

3. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 2, characterized in that, The step of performing a Thevenin equivalent transformation on the peripheral power grid, using the boundary nodes of the core region as ports, to obtain a multi-port Thevenin equivalent circuit includes: Establish node voltage equations that include the core region and the peripheral power grid; When the peripheral power grid does not contain a power source, the external nodes in the peripheral power grid are eliminated to obtain the equivalent admittance matrix of the boundary node, and a multi-port Thevenin equivalent circuit is constructed.

4. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 3, characterized in that, After establishing the node voltage equations that include the core region and the peripheral power grid, the method further includes: When the peripheral power grid includes a power source, the equivalent admittance matrix and equivalent current source of the boundary node are obtained by solving the node voltage equation; The inverse of the equivalent admittance matrix is ​​used as the equivalent impedance matrix; The product of the equivalent impedance matrix and the equivalent current source is used as the open-circuit voltage phasor; A multi-port Thevenin equivalent circuit is constructed based on the equivalent impedance matrix and the open-circuit voltage phasor.

5. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 2, characterized in that, After constructing a simplified model of the provincial power grid, the method further includes: Obtain the electrical quantities at key nodes in the full-scale detailed model and the simplified model, respectively; Calculate the error between the electrical quantities of the full-scale detailed model and the simplified model at the key node, and determine whether the error is greater than or equal to a preset error threshold; If so, the number of layers in the adjacency topology is increased, and the simplified model is reconstructed until the error is less than the preset error threshold.

6. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 5, characterized in that, The step of calculating the error between the electrical quantities at the key nodes of the full-scale detailed model and the simplified model, and determining whether the error is greater than or equal to a preset error threshold, includes: If there are multiple key nodes, the error between the electrical quantities of the full-scale detailed model and the simplified model at the multiple key nodes is calculated to obtain multiple errors; Based on the hierarchy of each key node in the core area, a preset weight coefficient is determined; Calculate the weighted average of the multiple errors based on the weight coefficients of the key nodes; Determine whether the weighted average of the multiple errors is greater than or equal to a preset error threshold.

7. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 1, characterized in that, The process of encapsulating the primary and secondary detailed models of the site into a site model that only exposes electrical and control interfaces includes: A topology analysis is performed on both sides of the model to extract the common interface node set; the two sides of the model include the simplified model and the station-level first and second detailed models. Record the correspondence, voltage level, and reference value of each common interface node in the common interface node set in the two side models to form an interface mapping table; Based on the interface mapping table, design the electrical interface and the control interface; The primary and secondary detailed models at the site level are encapsulated into a site model that exposes only the electrical interface and the control interface to the outside world.

8. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 7, characterized in that, The topology analysis of the two side models, extracting the common interface node set, includes: Extract the set of boundary nodes directly connected to the target station from the simplified model, as well as the set of external connection ports from the station-level first and second detailed models; Based on node name, voltage level, and topology association, the boundary node set is matched with the external connection port set to determine the candidate interface node set; Nodes in the candidate interface node set that satisfy the continuity and consistency conditions are included in the common interface node set; wherein, the continuity condition is that the voltage is equal and the current is continuous in the two side models, and the consistency condition is that the reference voltage and reference power are consistent in the two side models.

9. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 7, characterized in that, The design of electrical interfaces and control interfaces based on the interface mapping table includes: Based on the interface mapping table, electrical pins are set for each common interface node to form an electrical interface; the attributes of the electrical pins include name, voltage level, dimension, and data type; the electrical interface is used for power exchange between the simplified model and the station model; Based on the interface mapping table, virtual pins or global variables are used to map logic signals to form a control interface; the logic signals include trip commands, reclosing signals, circuit breaker status, and external blocking signals; the control interface is used for logic signal interaction between the simplified model and the station model.

10. The collaborative simulation modeling method for provincial power grids and local power stations according to claim 1, characterized in that, The simulation test involves setting up multiple fault scenarios on the joint simulation model to verify the collaborative characteristics among multiple secondary protection devices within the target site, including: An electromagnetic transient simulation engine is used, and the simulation step size and total simulation duration are set. Simulation tests were conducted by setting up three types of fault scenarios: line fault, bus fault, and transformer fault. The timing of the full-process operation of multiple secondary protection devices in the target site under various fault conditions was recorded. By comparing the timing of the entire process with the expected protection settings, the synergistic characteristics among the multiple sets of secondary protection devices are verified.

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