A modeling method of a power grid black start scheme based on PSD-BPA and oriented to off-grid power start

Abstract

The application discloses a kind of based on PSD-BPA and the modeling method of power grid black start scheme facing off-grid power supply start, it includes: the text line of storage network data and modification data is handled;Topology analysis is carried out to power grid;Generation calculates the power flow simulation data file of external network equivalent parameter, and respectively generate the power flow simulation data file suitable for network frame recovery stage analysis and load recovery stage analysis facing each black start sub-network of target power grid;Generation calculates the stability simulation data file of external network equivalent parameter, and respectively generate the stability simulation data file suitable for network frame recovery stage analysis and load recovery stage analysis facing each black start sub-network of target power grid;Calculate external network equivalent parameter, and correct the power flow and stability simulation data file corresponding to each black start sub-network.The application is helpful to quickly build simulation model for checking black start scheme, effectively improve the speed and efficiency of simulation analysis black start scheme.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a modeling method for a black start scheme of the power grid based on PSD-BPA and oriented towards the startup of external power sources. Background Technology

[0002] Black start refers to the process of gradually restoring system operation by starting self-starting units within the power system or by using external starting power sources to power other units in the system in the event of a complete power outage or a large-scale local power grid blackout. A scientific and reasonable black start scheme plays a crucial role in improving system recovery speed and reducing accident losses after a major power outage.

[0003] Based on the nature of the black-start power source, power grid black-start schemes can be divided into two types: those based on external power sources and those based on internal hydropower units. Starting the power grid based on external power sources essentially involves starting the external power grid via inter-provincial AC interconnection lines.

[0004] After power grid analysts identify one or more alternative black-start schemes based on experience, they need to use power system simulation analysis software to determine the safety and rationality of these schemes. For black-start schemes involving external power sources, due to the large short-circuit capacity and high intensity of the external power grid, it is generally assumed that problems such as generator self-excitation and overvoltage exceeding limits will not occur during the black-start process. Therefore, only the steady-state voltage level of the power grid during grid restoration and the stability during load restoration are considered. When analyzing the steady-state voltage level of the power grid during grid restoration, the focus is mainly on the scenario where each black-start subgrid is restored to power via a single AC line and a single transformer. When analyzing the stability of the power grid during load restoration, the focus is mainly on the scenario where each black-start subgrid has restored AC lines and transformers operating in parallel. Electromechanical transient simulation software is generally used for the analysis of the aforementioned issues. In China, PSD-BPA, produced by the China Electric Power Research Institute, is the most widely used.

[0005] PSD-BPA uses text files to store power flow data and stability data separately. Taking power flow data as an example, the text lines store control statements or network data. Network data can be further subdivided into network node data and network branch data. These data are represented by data cards with a fixed format. One data card corresponds to one line in the data file. The position and character length of each data column (also called field or attribute) that makes up the data card are fixed in the text line. For example, the balancing node parameters are called the "BS" card, and its node name and reference voltage are in columns 8-14 and 15-18 of the text line, respectively.

[0006] When power grid analysts use PSD-BPA to model black-start scenarios, they typically separate the target power grid data and external power grid data manually, based on existing simulation data describing typical operating modes. As the characteristics of PSD-BPA data files suggest, the text-based format makes querying, browsing, and editing data less intuitive and convenient, making manual construction of black-start simulation models extremely time-consuming and labor-intensive. For example, when extracting data from the State Grid's operating mode data, given the large number of power grid nodes, lines, transformers, and other components, analysts must first search through tens of thousands of text lines in the power flow data file for the power flow parameters belonging to that power grid, and then search through tens of thousands of text lines in the stability data file for the stability parameters belonging to that power grid. In summary, manually constructing black-start scenarios for external power source startup is inefficient and prone to errors. Engineering practice has also shown that the time spent on modeling and simulating black-start scenarios far exceeds the time spent on simulation analysis.

[0007] Currently, there are no relevant technologies, either domestically or internationally, to directly apply PSD-BPA data describing typical operating modes to the simulation modeling of black start schemes for power grids based on external power sources. Summary of the Invention

[0008] In view of this, the present invention provides a modeling method for a grid black start scheme based on PSD-BPA and oriented towards off-grid power source startup.

[0009] This invention discloses a modeling method for a grid black start scheme based on PSD-BPA and oriented towards off-grid power source startup, which includes:

[0010] Step 1: Establish a data structure for storing various types of network data; read the power flow data file in PSD-BPA format that describes typical operating modes, and process the text lines according to the data type identified by the text lines; process each text line storing network data; establish a data structure for storing modified data; process each text line storing modified data.

[0011] Step 2: Perform topology analysis on the power grid;

[0012] Step 3: Generate power flow simulation data files for calculating equivalent parameters of the external network, and generate power flow simulation data files suitable for network restoration stage analysis and load restoration stage analysis for each black start subnet of the target power grid;

[0013] Step 4: Generate stability simulation data files for calculating equivalent parameters of the external network, and generate stability simulation data files suitable for network restoration phase analysis and load restoration phase analysis for each black-start subnet of the target power grid;

[0014] Step 5: Calculate the equivalent parameters of the external network and correct the power flow and stability simulation data files corresponding to each black-start subnet.

[0015] Furthermore, the establishment of a data structure for storing various types of network data includes:

[0016] Establish a hash table to store the correspondence between node feature identifiers and node numbers. The key of the hash table is the node feature identifier, and the value of the hash table is the number corresponding to the node.

[0017] Create a hash table to store the correspondence between node numbers and text line information. The key of the hash table is the node number, and the value of the hash table is a list. The elements of the list are tuples consisting of the data type of the text line identifier, the data modification identifier in the text line, and the corresponding line number of the text line in its file.

[0018] Create a hash table to store the mapping between node numbers and partition names. The key of the hash table is the node number, and the value of the hash table is the partition name.

[0019] Create a hash table to store the correspondence between partition names and node numbers. The key of the hash table is the partition name, and the value of the hash table is a list of node numbers as elements.

[0020] Create a hash table to store the correspondence between node numbers and owner names. The key of the hash table is the node number, and the value of the hash table is the owner name.

[0021] Create a hash table to store the correspondence between owner names and node numbers. The key of the hash table is the owner name, and the value of the hash table is the node number.

[0022] Establish a hash table to store the correspondence between AC line feature identifiers and text line information. The text line stores AC line parameters. The key of the hash table is the AC line feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is a tuple consisting of the line segment number, the small switch branch identifier, the data modification identifier in the text line, and the corresponding line number of the text line in its file.

[0023] Establish a hash table to store the correspondence between AC line high-resistance feature identifiers and text line numbers. The text lines store AC line high-resistance parameters. The key of the hash table is the AC line high-resistance feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is a tuple. The tuple consists of the data modification identifier in the text line and the corresponding line number of the text line in its file.

[0024] Establish a hash table to store the correspondence between quickly adjustable line complement feature identifiers and text line information. The text line stores the quickly adjustable line complement parameters. The key of the hash table is the line complement feature identifier, and the value of the hash table is a list. The list element is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file.

[0025] Create a hash table to store the correspondence between transformer / phase shifter feature identifiers and text line information. The text lines store transformer / phase shifter parameters. The key of the hash table is the transformer / phase shifter feature identifier, and the value of the hash table is a list. The list element is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file.

[0026] Create a hash table to store the correspondence between the characteristic identifiers of the control parameters of the on-load voltage regulating transformer / phase shifter and the text line information. The text line stores the control parameters of the on-load voltage regulating transformer / phase shifter. The key of the hash table is the characteristic identifier of the control parameter of the on-load voltage regulating transformer / phase shifter, and the value of the hash table is a list. The list element is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file.

[0027] Create a hash table to store the correspondence between the feature identifiers of the modular UPFC serial terminals and the line numbers of the text lines. The key is the feature identifier of the modular UPFC serial terminal, which is a tuple consisting of the node numbers at both ends and the parallel loop identifier. The value is a tuple consisting of the line numbers of the text lines storing the parameters and supplementary data of the modular UPFC serial terminals in their respective files.

[0028] Establish a hash table to store the correspondence between DC line feature identifiers and text line information. The text lines store DC line parameters. The key of the hash table is the DC line feature identifier, which is a tuple consisting of the node numbers at both ends. The value of the hash table is a list, and the elements of the list are tuples consisting of the data modification identifier in the text line and the corresponding line number of the text line in its data file.

[0029] Create a hash table to store the correspondence between LCC DC control parameter feature identifiers and text line numbers. The key is the LCC DC control parameter feature identifier, which is a tuple consisting of the rectifier low-side converter node number, rectifier high-side converter node number, inverter low-side converter node number, and inverter high-side converter node number. The value is the corresponding line number of the text line storing the LCC DC control parameter in its respective file.

[0030] Furthermore, the processing of the text lines includes:

[0031] Extract text lines from the data file and save them to the system's baseline capacity;

[0032] Retrieve network data, iterate through all text lines storing network data, and process each text line storing network data;

[0033] Check if the modified data exists. If it does, retrieve the modified data and iterate through all the text lines that store the modified data, processing each text line that stores the modified data.

[0034] Further, the processing of each line of text stored in the network includes:

[0035] When the text line stores one of the following data types: AC node parameters, AC node supplementary data, DC node parameters, DC node supplementary data, switchable reactor / capacitor bank parameters, or modular UPFC parallel terminal parameters, the hash table storing the correspondence between node feature identifiers and node numbers is queried or updated based on the node feature identifiers in the text line; the hash table storing the correspondence between node numbers and text line information is also updated.

[0036] When the text line stores AC node parameters or DC node parameters, the partition name is obtained from the text line, and the hash table used to store the correspondence between node numbers and partition names and the hash table used to store the correspondence between partition names and node number lists are updated; the owner name is also obtained from the text line, and the hash table used to store the correspondence between node numbers and owner names and the hash table used to store the correspondence between owner names and node number lists are updated.

[0037] When the text line stores various AC line parameters, the AC line types include symmetrical lines and asymmetrical lines. The hash table storing the correspondence between node feature identifiers and node numbers is queried or updated based on the feature identifiers of the two ends of the text line. If the text line stores symmetrical AC line parameters, the AC line corresponding to the text line is determined as a small switch branch based on the per-unit reactance value in the text line. The hash table storing the correspondence between AC line feature identifiers and text line information is then updated.

[0038] Furthermore, the processing of each line of text stored in the network data also includes:

[0039] When the text line stores AC line high-resistance parameters, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between AC line high-resistance feature identifiers and text line numbers.

[0040] When the text line stores line complement parameters that can be adjusted quickly, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between line complement feature identifiers that can be adjusted quickly and text line information.

[0041] When the text line stores transformer / phase shifter parameters, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between transformer / phase shifter feature identifiers and text line information.

[0042] When the text line stores control parameters of a load-regulating transformer / phase shifter, the hash table that stores the correspondence between node feature identifiers and node numbers is queried or updated based on the feature identifiers of the nodes at both ends of the text line; the hash table that stores the correspondence between the feature identifiers of the load-regulating transformer / phase shifter control parameters and the text line information is updated.

[0043] Furthermore, the processing of each line of text stored in the network data also includes:

[0044] When the text line stores modular UPFC serial terminal parameters or modular UPFC serial terminal supplementary data, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between modular UPFC serial terminal feature identifiers and text line numbers.

[0045] When the text line stores various DC line parameters, the DC line types include two-end DC lines, multi-end DC lines, flexible DC lines, and LCC DC lines. Based on the feature identifiers of the two-end nodes in the text line, the hash table storing the correspondence between node feature identifiers and node numbers is queried or updated; the hash table storing the correspondence between DC line parameter feature identifiers and text line numbers is updated.

[0046] When the text line stores LCC DC control parameters, based on the feature identifiers of the rectifier low-side converter node, rectifier high-side converter node, inverter low-side converter node, and inverter high-side converter node in the text line, query or update the hash table that stores the correspondence between node feature identifiers and node numbers; update the hash table that stores the correspondence between LCC DC control parameter feature identifiers and text line numbers.

[0047] When a text line stores region control data, the text line is ignored.

[0048] Furthermore, the processing of each text line storing modified data includes:

[0049] When the text line stores new AC node parameters, supplementary AC node data, DC node parameters, supplementary DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between node feature identifiers and node numbers is queried or updated based on the node feature identifiers in the text line; the hash table storing the correspondence between node numbers and text line information is updated; when the text line stores new AC node parameters or DC node parameters, the list of deleted node numbers or the list of new node numbers stored in the data structure established for storing modified data is updated based on the node number.

[0050] When the text line stores the parameters of the newly added AC node or DC node, the hash table that stores the correspondence between the node number and the partition name, as well as the hash table that stores the correspondence between the partition name and the node number list, are also updated according to the partition name in the text line.

[0051] When the text line stores parameters for newly added AC or DC nodes, the hash table storing the correspondence between node numbers and owner names, as well as the hash table storing the correspondence between the list of owner names and node numbers, are also updated based on the owner name in the text line.

[0052] Furthermore, the processing of each text line storing modified data also includes:

[0053] When the text line stores the content of deleting AC node parameters, supplementing AC node data, DC node parameters, supplementing DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between the node number and the text line information is updated according to the node feature identifier in the text line; when the text line stores the content of deleting AC node parameters or DC node parameters, the list storing the deleted node numbers or the list storing the added node numbers in the data structure established for storing modified data is updated according to the node number.

[0054] When the content stored in the text line is the restoration of deleted AC node parameters, or supplementary AC node data, or DC node parameters, or supplementary DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between the node number and the text line information is updated according to the node feature identifier in the text line; when the content stored in the text line is the restoration of deleted AC node parameters or DC node parameters, the list of deleted node numbers or the list of added node numbers in the data structure established for storing modified data is updated according to the node number.

[0055] When the text line stores information about correcting AC node parameters, supplementing AC node data, DC node parameters, supplementing DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between node numbers and text line information is updated based on the node feature identifier in the text line. When the text line stores information about modifying AC node parameters or DC node parameters, the hash table storing the correspondence between node numbers and partition names, the hash table storing the correspondence between partition names and node number lists, the hash table storing the correspondence between node numbers and owner names, and the hash table storing the correspondence between owner names and node number lists are updated based on the partition name and owner name in the text line, respectively.

[0056] Furthermore, the processing of each text line storing modified data also includes:

[0057] When the text line stores data of one of the following types: AC line high-resistance parameters, quickly adjustable line series compensation parameters, transformer / phase shifter parameters, on-load voltage regulating transformer / phase shifter control parameters, or DC line parameters, the modification includes adding data, deleting data, correcting data, and restoring deleted data, and updating the hash table that stores the correspondence between branch feature identifiers and text line information; when the text line stores data of adding or correcting AC line parameters, it is handled in a similar manner; when the text line stores data of deleting or restoring deleted AC line parameters, and the segment number in the text line is not zero and not blank, and the parallel circuit identifier is not "*" and not blank, it is also handled in a similar manner.

[0058] When the text line stores information about deleting or restoring deleted AC line parameters, if the parallel circuit identifier in the text line is "*" or blank, it indicates that all parallel AC lines have been deleted or restored. The hash table corresponding to the storage node feature identifier and text line information is updated according to the hash table of the correspondence between the text line and the storage node feature identifier and node number. If the segment number in the text line is zero or blank, it indicates that all AC lines composed of connected segments have been deleted or restored. The hash table corresponding to the storage node feature identifier and text line information is updated according to the hash table of the correspondence between the text line and the storage node feature identifier and node number.

[0059] Furthermore, the processing of each text line storing modified data also includes:

[0060] When the content stored in the text line is the modification of the generation / load percentage by partition, the line number of the text line in its file is used as the key, the partition name is retrieved from the text line and used as the value, and the key-value pair is added to the hash table that establishes the data structure for storing the modified data and stores the correspondence between the text line number and the partition name when the generation / load percentage is modified by partition; when the content stored in the text line is the modification of the generation / load percentage by a specified partition, the line number of the text line in its file is used as the key, all partition names are retrieved from the text line and a list constructed from all partition names is used as the value, and the key-value pair is added to the hash table that establishes the data structure for storing the modified data and stores the correspondence between the text line number and the specified partition name when the generation / load percentage is modified by a specified partition.

[0061] When the content stored in the text line is the modification of the power generation / load percentage by owner, the line number of the text line in its file is used as the key, the owner name is retrieved from the text line and used as the value, and the key-value pair is added to the hash table that stores the correspondence between the text line number and the owner name when the power generation / load percentage is modified by owner in the data structure used to store the modified data. When the content stored in the text line is the modification of the power generation / load percentage by a specific owner, the line number of the text line in its file is used as the key, all owner names are retrieved from the text line and the list constructed from the owner names is used as the value, and the key-value pair is added to the hash table that stores the correspondence between the text line number and the specified owner name when the power generation / load percentage is modified by a specified owner in the data structure used to store the modified data.

[0062] Furthermore, the establishment of the data structure for storing modified data includes:

[0063] Step 11: For node parameters, create a list to store the IDs of newly added nodes and a list to store the IDs of deleted nodes. The elements in the lists are node IDs.

[0064] Step 12: Create a hash table to store the mapping between line numbers of text lines and partition names when the power generation / load percentage is modified by partition. The key is the line number of the text line in its file, and the value is the partition name. Create another hash table to store the mapping between line numbers of text lines and a list of specified partition names when the power generation / load percentage is modified by a specified partition. The key is the line number of the text line in its file, and the value is a list of partition names.

[0065] Step 13: Create a hash table to store the mapping between line numbers of text lines and owner names when the power generation / load percentage is modified by the owner. The key is the line number of the text line in its file, and the value is the owner name.

[0066] Further, step 2 includes:

[0067] Step 21: Create a hash table to store the relationship between node numbers and new node numbers, with node numbers as keys and new node numbers as values; create a hash table to store the relationship between new node numbers and lists of node numbers, with new node numbers as keys and lists of node numbers as values.

[0068] Step 22: Traverse the hash table storing the correspondence between AC line feature identifiers and text line information, and obtain the connected subgraphs describing the AC small switch branches through topological analysis; for each connected subgraph, if there is more than one vertex in the connected subgraph, treat all nodes corresponding to the connected subgraph as one node, create a new number for all nodes corresponding to the connected subgraph that is different from all node numbers, and update the hash table in step 21 with the node number and the new node number;

[0069] Step 23: Create a set of text line numbers that are independent of the external network equivalent simulation data. The text lines are stored in the file where the network data was stored in Step 1, and the data stored in the text lines must be set to invalid when constructing the external network equivalent simulation data.

[0070] Step 24: For each black-start subnet of the target power grid, establish a set of text line numbers for simulation analysis during the grid restoration phase. In the network data file of Step 1, the branches and nodes represented by the text lines belong to each black-start subnet in terms of electrical topology, and the branch and node data do not need to be modified. For each black-start subnet of the target power grid, establish a set of text line numbers for simulation analysis during the load restoration phase. In the network data file of Step 1, the branches and nodes represented by the text lines belong to each black-start subnet in terms of electrical topology, and the branch and node data do not need to be modified.

[0071] Step 25: For each black start subnet of the target power grid, establish a set of node numbers whose node parameters need to be modified when constructing the simulation data of the black start subnet, a set of text line information corresponding to the nodes that need to be modified, a set storing the partition name to which the nodes in the black start subnet belong, and a set storing the owner name to which the nodes in the black start subnet belong. The text line information is a tuple composed of the text line number and the data type of the text line identifier.

[0072] Step 26: Traverse the hash table storing the characteristic identifiers and text line information of a certain type of AC series branch. The types of AC branches include AC lines, transformers / phase shifters, UPFC series terminals, and line series compensation that can be quickly adjusted. Combine the topology information required to divide the black start subnet in the black start scheme and the hash table in Step 21, perform AC topology analysis on the network data and the power grid represented by the modified data to obtain the AC connectivity subgraph describing the external network and the connectivity subgraph corresponding to each black start subnet of the target power grid in the load recovery stage and the grid recovery stage, and update the data structure in Steps 23, 24 and 25.

[0073] Step 27: Establish a set of node numbers whose node parameters need to be modified when constructing external network equivalent simulation data, and a set of text line information corresponding to the nodes that need to be modified. The text line information is a tuple composed of text line number and the data type of the text line identifier.

[0074] Step 28: Traverse the hash table storing DC line feature identifiers and text line information, perform DC topology analysis on the network data and the power grid represented by the modified data, update the connected subgraphs of the external network and each black start subnet described in Step 27, and update the data structures in Steps 23, 24 and 27.

[0075] Further, step 3 includes:

[0076] Step 31: Create a new power flow data file for calculating the equivalent parameters of the external network; create a new power flow data file for each black-start subnet of the target power grid, suitable for analyzing the network restoration phase; create a new power flow data file for each black-start subnet of the target power grid, suitable for analyzing the load restoration phase.

[0077] Step 32: For each file in Step 31, write the specified power flow start, set the system baseline capacity, and specify the power flow result output control statement line by line. The system baseline capacity is taken from the power flow data file in PSD-BPA format that describes the typical operation mode, and the baseline capacity is saved in the processing of the text line according to the data type identified by the text line.

[0078] Step 33: Read the power flow data file in PSD-BPA format that describes the typical operating mode line by line, and process the network data corresponding to the text line according to the data type identified by the text line;

[0079] Step 34: Write control statements line by line to specify the data saving location. The default data saving location is the new file in Step 31. Then, read the power flow data file in PSD-BPA format that describes the typical operation mode line by line, and process the modified data in the text line according to the data type identified by the text line.

[0080] Step 35: For the file in Step 31, write the control statements for the specified power flow calculation process and the specified power flow termination line by line.

[0081] Furthermore, the processing of the network data corresponding to the text line includes:

[0082] When the text line number is modified in the external network equivalent simulation data, if the data type of the text line identifier is a node parameter, the text line content is modified to the default value of the AC node parameter, and then the text line content is written into the power flow data file used in step 31 to calculate the external network equivalent parameters, and then the next line is read.

[0083] When the text line number is not in the set of text line numbers that are not related to the storage and external network equivalent simulation data, the text line content is written to the power flow data file used in step 31 to calculate the external network equivalent parameters, and then the next line is read.

[0084] When the line number of a text line matches the set of line numbers for load recovery phase analysis corresponding to a certain black-start subnet, the text line content is written to the power flow data file for load recovery phase analysis of that subnet in step 31. If the text line is not in the set of line numbers for network structure recovery phase analysis of that subnet, the text line content is copied, a comment character is added to the beginning of the text line, and then it is written to the power flow data file for network structure recovery phase analysis of that subnet in step 31. If the text line is in the set of line numbers for network structure recovery phase analysis of that subnet, the text line content is written to the power flow data file for network structure recovery phase analysis of that subnet in step 31. Then proceed to the next line to read.

[0085] When the text line number needs to be modified in the text line information set corresponding to a node in the simulation data of a certain black start subnet, if the data type of the text line identifier is a node parameter, modify the text line content to the default value of the AC node parameter, and then write the text line content into the power flow data file for the subnet structure recovery stage and load recovery system analysis in step 31, and then move on to the next line to read.

[0086] Furthermore, the processing of modified data in the text line includes:

[0087] When the text line number is in the hash table corresponding to the text line number and partition name when the storage generation / load percentage is modified by partition in step 2 of establishing the data structure for storing modified data, check the hash table corresponding to the storage partition name and node number list according to the partition name. If the corresponding node number list is not empty, write the text line into the power flow data file used in step 31 to calculate the external network equivalent parameters; for each set of partition names to which the nodes in the storage black start subnet belong, check whether the partition name is in the set. If it is, write the text line into the power flow data file for the analysis of the subnet network structure recovery stage and load recovery stage in step 31 respectively; then move on to the next line to read;

[0088] When the text line number is in the hash table corresponding to the text line number and the partition name list when the power generation / load percentage is modified by specified partition in step 2 of establishing the data structure for storing modified data, the hash table corresponding to the partition name and the node number list is traversed. If the corresponding node number list is not empty, the partition name is saved in a temporary list. After traversing the partition name list, if the temporary list is not empty, the text line content is copied and the partition name stored in the text line is modified to the element existing in the temporary list. Then the modified text line is... The content is written into the power flow data file used in step 31 to calculate the equivalent parameters of the external network; a temporary list is created for each black-start subnet, and the partition names in the partition name list are queried in turn to see if they are in the set of partition names of the nodes in the storage subnet. If so, the partition names are saved in the temporary list. After traversing the partition name list, if the temporary list is not empty, the text line content is copied and the partition names stored in the text line are modified to the elements existing in the temporary list. The modified text line content is then written into the power flow data file used in step 31 for the subnet network structure recovery phase and load recovery phase analysis respectively; then the next line is read.

[0089] Furthermore, the processing of modified data in the text line also includes: when the text line number is in the hash table of the correspondence between the text line number and the owner name when the storage power generation / load percentage is modified by the owner in step 3 of establishing the data structure for storing modified data, check the hash table of the correspondence between the storage owner name and the node number list according to the owner name. If the corresponding node number list is not an empty list, write the text line to the file in step 31; for the set of owner names of each node in the storage black start subnet in step 25, query whether the owner name is in the set. If it is, write the text line to the power flow data file for the subnet network structure recovery phase and load recovery phase analysis in step 31 respectively; then move on to the next line to read;

[0090] When the text line number is in the hash table corresponding to the text line number and the list of owner names when the power generation / load percentage is modified according to the specified owner in step 3 of establishing the data structure for storing modified data, the process iterates through each owner name in the owner name list. It then checks the hash table corresponding to the list of owner names and node numbers. If the corresponding node number list is not empty, the owner name is saved in a temporary list. After iterating through the owner name list, if the temporary list is not empty, the text line content is copied, and the owner name stored in the text line is modified to match the element existing in the temporary list. Finally, the modified text line is... The text line content is written into the power flow data file used in step 31 to calculate the equivalent parameters of the external network; a temporary list is created for each black-start subnet, and the owner name in the owner name list is checked in turn to see if it is in the set of owner names of the nodes in the storage subnet in step 25. If so, the owner name is saved in the temporary list. After traversing the owner name list, if the temporary list is not empty, the text line content is copied and the owner name stored in the text line is modified to the element existing in the temporary list. The modified text line content is then written into the power flow data file for the subnet network structure recovery stage and load recovery stage analysis in step 31 respectively; then the next line is read.

[0091] If the text line does not fall into any of the above four categories, proceed to step 33.

[0092] Further, step 4 includes:

[0093] Step 41: Read the stable data file depicting the typical operating mode line by line. The file stores the stable data corresponding to the power flow data file in the data structure used to store various types of network data. Check if it contains a text line that stores the data card specified by the stable parameter file. If it does, merge the content of the stable parameter file given in the text line with the content of the stable data file to create a new text file, and then read the new file line by line. If it does not contain a text line that stores the data card specified by the stable parameter file, then read the other text lines in the stable data file line by line.

[0094] Step 42: Create a new stable data file for calculating the equivalent parameters of the external network; create a new stable data file for each black-start subnet of the target power grid, suitable for analyzing the grid recovery phase; create a new stable data file for each black-start subnet of the target power grid, suitable for analyzing the load recovery phase.

[0095] Step 43: Process each line of text read in step 41.

[0096] Further, step 43 includes:

[0097] When the text line stores the calculation control CASE card, modify the power flow mode name stored in the text line to the power flow mode name given in the power flow start control statement in the corresponding file in step 31, and then write it into the stable data file used to calculate the equivalent parameters of the external network in step 42; for each black start subnet of the target power grid, modify the power flow mode name stored in the text line to the power flow mode name given in the power flow start control statement in the corresponding file, and then write it into the stable data file corresponding to step 42.

[0098] When the text line storage content does not contain node feature identifiers, the text line content is directly written to the stable data file used in step 42 to calculate the equivalent parameters of the external network; for each black start subnet of the target power grid, the text line content is directly written to the corresponding stable data file in step 42; then proceed to the next line to read.

[0099] Furthermore, step 43 also includes:

[0100] When the text line stores node feature identifiers, the corresponding node number is retrieved from the hash table that stores the correspondence between node feature identifiers and node numbers. Then, combined with the hash table that stores the relationship between node numbers and new node numbers, the system searches in the AC connectivity subgraph describing the external network to see if there is a corresponding vertex for the node feature identifier. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which the node parameters need to be modified, or if there is a corresponding vertex and the corresponding node number is in the set of node numbers for which the node parameters need to be modified, but the text line does not store DC control system model parameters, then the text line content is written into the stable data file used in step 42 to calculate the equivalent parameters of the external network.

[0101] Furthermore, step 43 also includes:

[0102] For each black-start subnet of the target power grid, in the connected subgraph corresponding to the black-start subnet during the load recovery phase, check whether there is a corresponding vertex for the node feature identifier. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which the node parameters need to be modified, or if there is a corresponding vertex and the corresponding node number is in the set of node numbers for which the node parameters need to be modified, but the text line does not store DC control system model parameters, then write the text line content into the stable data file for the load recovery phase analysis in step 42.

[0103] For each black-start subnet of the target power grid, in the connected subgraph corresponding to the black-start subnet during the grid restoration phase, if the text line stores the stability parameters of AC branch type components, then the branch feature identifier is obtained from the text line, and the corresponding edge is checked in the connected subgraph. If it exists, the text line content is written into the stability data file for grid restoration phase analysis in step 42. If it does not exist, the text line content is copied, a comment character is added to the beginning of the text line, and then it is written into the stability data file for grid restoration phase analysis of that subnet in step 42. When the text line does not store the stability parameters of AC branch type components, the node feature identifier stored in the text line is checked to see if there is a corresponding vertex in the connected subgraph. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers whose node parameters need to be modified, or if there is a corresponding vertex and the corresponding node number is in the set of node numbers whose node parameters need to be modified, but the text line does not store DC control system model parameters, then the text line content is written into the stability data file for grid restoration phase analysis in step 42.

[0104] Further, step 5 includes:

[0105] Step 51: Using the short-circuit current calculation program provided by PSD-BPA, based on the power flow data file used in Step 31 to calculate the equivalent parameters of the external network and the stability data file used in Step 42 to calculate the equivalent parameters of the external network, obtain the positive sequence and zero sequence equivalent impedances of the inter-provincial AC tie lines of each sub-network of the target power grid at the corresponding nodes on the external network side.

[0106] Step 52: For each black-start subnet of the target power grid, in the power flow data file during the analysis of the grid restoration phase, write a text line storing equivalent AC node parameters, set the node type to balanced node, and write a text line storing equivalent AC line parameters. The equivalent AC line connects the equivalent AC node and the node on the external network side of the inter-provincial tie line that started the subnet. The line impedance parameter is the positive-sequence equivalent impedance parameter obtained in Step 51. The same process is applied in the power flow data file during the analysis of the load restoration phase.

[0107] Step 53: For each black-start subnet of the target power grid, in the stability data file of the analysis network restoration phase, write a text line storing the parameters of the infinite bus model. This text line corresponds to the text line storing the equivalent AC node parameters in Step 52. That is, the equivalent AC node is regarded as an infinite bus. Then write a text line storing the equivalent AC line parameters. This text line corresponds to the text line storing the equivalent AC line parameters in Step 52. The line impedance parameters are the zero-sequence equivalent impedance parameters obtained in Step 51. The same process is used in the stability data file of the analysis load restoration phase.

[0108] Because of the adoption of the above technical solution, the present invention has the following advantages:

[0109] (1) The agile modeling method for black start scheme of power grid based on PSD-BPA and oriented towards external power source start-up provided by the present invention, combined with computer program, agilely generates simulation data suitable for the analysis of black start subgrid structure recovery stage and load recovery stage, which reduces a lot of manual operation, saves modeling time, and can help system analysts concentrate their main time and energy on the verification analysis of black start scheme.

[0110] (2) The agile modeling method for the black start scheme of the power grid based on PSD-BPA and oriented towards the start of external power sources provided by the present invention has the advantages of strong operability, comprehensive consideration of factors and reasonable scheme, and has high engineering practical value. Attached Figure Description

[0111] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0112] Figure 1 This is a flowchart illustrating a modeling method for a grid black start scheme based on PSD-BPA and oriented towards off-grid power source startup, according to an embodiment of the present invention.

[0113] Figure 2 This is a schematic diagram of a power flow data file in PSD-BPA format for a nine-node example according to an embodiment of the present invention.

[0114] Figure 3 This is an equivalent circuit diagram of two three-winding transformers operating in parallel according to an embodiment of the present invention. Detailed Implementation

[0115] The present invention will be further described in conjunction with the accompanying drawings and embodiments. The described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0116] like Figure 1 As shown, this invention provides a modeling method for a grid black start scheme based on PSD-BPA and oriented towards off-grid power source startup, comprising the following steps:

[0117] (1) Analyze the power flow data file that describes the typical operating mode.

[0118] Figure 2This document presents a power flow data file in PSD-BPA format for a nine-node example. The PSD-BPA power flow data includes control statements and network data. Power flow control statements are divided into three levels. Text lines representing level one, level two, and level three control statements begin with the characters "(", " / ", and ">", and end with ")", "\", and "<", respectively. Network data includes node data, branch data, etc., and these types of data are referred to as data cards. Each data card corresponds to one text line. The type of data card is distinguished by the first 1 to 3 characters of the text line. For example, text lines starting with "B", "L", and "T" are respectively called AC node card, symmetrical AC line card, and two-winding transformer / phase shifter card. Each data card has a fixed text format and contains fields describing the model. The position of each field value within the text line is fixed. Taking the AC node card as an example, the data described in the first 20 columns is shown in Table 1.

[0119] Table 1. Format of some fields in the communication node card.

[0120]

[0121] In PSD-BPA, different types of network data are distinguished by the card type at the beginning of the text line, and network data of the same type are distinguished by corresponding feature identifiers. For example, node data or parallel branch data are not distinguished by node name, but by node name and reference voltage; that is, two different nodes can have the same node name but their reference voltages will necessarily be different. Similarly, transformers / phase shifters are distinguished by the node names at both ends, the corresponding reference voltage, and the parallel circuit identifier. AC lines are distinguished by the node names at both ends, the corresponding reference voltage, the parallel circuit identifier, and the line segment number. DC lines are distinguished by the node names at both ends and the corresponding reference voltage. Therefore, data of the same type can be searched using feature identifiers.

[0122] The specific steps involved in analyzing power flow data files that characterize typical operating modes are as follows:

[0123] (1.1) Establish a data structure for storing various types of network data, specifically by performing the following sub-steps:

[0124] (1.1.1) Establish a hash table to store the correspondence between node feature identifiers and node numbers. The key is the node feature identifier, which is a tuple consisting of the node name and the node reference voltage. The node reference voltage is an integer, and the value is the number corresponding to the node. When parsing a text line storing various types of data information, if the node feature identifier obtained from the text line is not the key in the hash table, then update the hash table. During the update, the node feature identifier is used as the key, and the number of elements in the hash table before the update is obtained. The number of elements is added to 1 to be regarded as the node number and used as the value corresponding to the key. The key-value pair is added to the hash table.

[0125] (1.1.2) Establish a hash table to store the correspondence between node numbers and text line information. The text line stores AC node parameters, AC node supplementary data, DC node parameters, DC node supplementary data, switchable reactor / capacitor bank parameters, or modular UPFC (Unified Power Flow Controller) parallel terminal parameters. The key of the hash table is the node number, and the value of the hash table is a list. The elements of the list are text line information. The text line information is a tuple consisting of the data type of the text line identifier, the data modification identifier in the text line, and the corresponding line number of the text line in its file.

[0126] (1.1.3) Create a hash table to store the correspondence between node numbers and partition names, with the node number as the key and the partition name as the value; create a hash table to store the correspondence between partition names and a list of node numbers, with the partition name as the key and the node number as the value as the list of elements; create a hash table to store the correspondence between node numbers and owner names, with the node number as the key and the owner name as the value; create a hash table to store the correspondence between owner names and a list of node numbers, with the owner name as the key and the node number as the list of elements.

[0127] (1.1.4) Establish a hash table to store the correspondence between AC line feature identifiers and text line information. The text line stores AC line parameters. The key of the hash table is the AC line feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is text line information. The text line information is a tuple consisting of the line segment number, the small switch branch identifier, the data modification identifier in the text line, and the corresponding line number of the text line in its file. Establish a hash table to store the correspondence between AC line high-resistance feature identifiers and text line numbers. The text line stores AC line high-resistance parameters. The key of the hash table is the AC line high-resistance feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is a tuple. The tuple consists of the data modification identifier in the text line and the corresponding line number of the text line in its file.

[0128] (1.1.5) Establish a hash table to store the correspondence between the line complement feature identifier and the text line information that can be quickly adjusted. The text line stores the line complement parameters that can be quickly adjusted. The key of the hash table is the line complement feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel loop identifier. The value of the hash table is a list, and the list element is the text line information. The text line information is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in the file to which it belongs.

[0129] (1.1.6) Establish a hash table to store the correspondence between transformer / phase shifter feature identifiers and text line information. The text line stores transformer / phase shifter parameters. The key of the hash table is the transformer / phase shifter feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is text line information. The text line information is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file.

[0130] (1.1.7) Establish a hash table to store the correspondence between the characteristic identifiers of the control parameters of the voltage regulating transformer / phase shifter under load and the text line information. The text line stores the control parameters of the voltage regulating transformer / phase shifter under load. The key of the hash table is the characteristic identifier of the control parameter of the voltage regulating transformer / phase shifter under load. The characteristic identifier of the control parameter of the voltage regulating transformer / phase shifter under load is a tuple consisting of the node numbers at both ends of the voltage regulating transformer / phase shifter under load. The value of the hash table is a list. The list element is the text line information. The text line information is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in the file to which it belongs.

[0131] (1.1.8) Establish a hash table to store the correspondence between the feature identifiers of the modular UPFC serial terminals and the line numbers of the text lines. The key is the feature identifier of the modular UPFC serial terminal, which is a tuple consisting of the node numbers at both ends and the parallel loop identifier. The value is a tuple consisting of the line numbers of the text lines storing the parameters of the modular UPFC serial terminals and the supplementary data of the modular UPFC serial terminals in the file to which they belong.

[0132] (1.1.9) Establish a hash table to store the correspondence between DC line feature identifiers and text line information. The text line stores DC line parameters. The key of the hash table is the DC line feature identifier, which is a tuple consisting of the node numbers at both ends. The value of the hash table is a list, and the elements of the list are text line information. The text line information is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its data file. Establish a hash table to store the correspondence between LCC (current source converter) DC control parameter feature identifiers and text line numbers. The key is the LCC DC control parameter feature identifier, which is a tuple consisting of the rectifier low-side converter node number, rectifier high-side converter node number, inverter low-side converter node number, and inverter high-side converter node number. The value is the corresponding line number of the text line storing the LCC DC control parameter in its file.

[0133] (1.2) Read the power flow data file in PSD-BPA format that describes the typical operating mode line by line, and process the text lines according to the data type identified by the text line as follows: obtain the text line of the control statement that stores the specified system base capacity, and save the system base capacity; obtain the network data, traverse all text lines storing network data, and process them in the manner described in the steps for processing each text line storing network data; check if the modified data exists, and if it does, obtain the modified data, traverse all text lines storing modified data, and process them in the manner described in the steps for processing each text line storing modified data.

[0134] The detailed methods for obtaining network data and modified data are as follows:

[0135] When a text line stores a control statement specifying the location for saving network data, search for the text line storing the control statement specifying the location for saving modified data. If the text line storing the control statement specifying the location for saving modified data exists but the network data and modified data are not saved in the same file, then merge the network data and modified data into a new text file. Traverse all text lines storing network data in the new file and process them according to step (1.3). Then traverse all text lines storing modified data in the new file and process them according to step (1.4). If the text line storing the control statement specifying the location for saving modified data exists and the network data and modified data are saved in the same file, read the file, traverse all text lines storing network data and process them according to step (1.3). Then traverse all text lines storing modified data and process them according to step (1.4). If the text line storing the control statement specifying the location for saving modified data does not exist, then traverse all text lines storing network data and process them according to step (1.3).

[0136] When a text line stores a control statement specifying the location for storing network node data, search for the text line storing the control statement specifying the location for storing network branch data and the text line storing the control statement specifying the location for storing modified data. If a text line stores a control statement specifying the location for storing network branch data, search for the text line storing the control statement specifying the location for storing network node data and the text line storing the control statement specifying the location for storing modified data. If a text line storing the control statement specifying the location for storing modified data exists, but the network node data, network branch data, and modified data are not stored in the same file, then merge the network node data, network branch data, and modified data into a new text file. In the new file, traverse all text lines storing network data and process them according to step (1.3). Then traverse all text lines storing modified data and process them according to step (1.4). If the text line containing the control statement specifying the location for storing modified data exists and the network node data, network branches, and modified data are stored in the same file, read the file, traverse all text lines storing network data, and process them according to step (1.3). Then traverse all text lines storing modified data and process them according to step (1.4). If the text line containing the control statement specifying the location for storing modified data does not exist and the network node data and network branch data are not stored in the same file, then merge the network node data and network branch data into a new text file. In the new file, traverse all text lines and process them according to step (1.3). If the text line containing the control statement specifying the location for storing modified data does not exist and the network node data and network branch data are in the same file, then traverse all text lines storing network data and process them according to step (1.3).

[0137] In practice, if a text line begins with the string " / MVA_BASE", it indicates that the text line stores control statements used to set the base capacity.

[0138] In practice, if a text line begins with the string " / NETWORK_DATA", it indicates that the text line stores control statements used to specify network data. For the string before the backslash "\", spaces are ignored, and the string is split by commas. A search is performed for a substring starting with "FILE=". If it does, and the substring to the right of "FILE=" is not "*", it indicates that the network data is stored in a separate text file, and the substring to the right of "FILE=" represents the file name. Otherwise, it indicates that the network data follows the text line starting with " / NETWORK_DATA".

[0139] In practice, if a text line begins with the string " / BRANCH_DATA", it indicates that the text line stores control statements used to specify network branch data. For the string before the backslash "\", spaces are ignored, and the string is split by commas. A search is conducted to find a substring starting with "FILE=". If it exists and the substring to the right of "FILE=" is not "*", it indicates that the network branch data is stored in a separate text file, and the substring to the right of "FILE=" represents the file name. Otherwise, the corresponding network branch data is located after the text line starting with " / BRANCH_DATA".

[0140] In practice, if a text line begins with the string " / BUS_DATA", it indicates that the text line stores control statements used to specify network node data. For the string before the backslash "\", spaces are ignored, and the string is split by commas. The system searches for a substring starting with "FILE=". If it does, and the substring to the right of "FILE=" is not "*", it indicates that the network node data is stored in a separate text file, and the substring to the right of "FILE=" represents the file name. Otherwise, the corresponding network node data is located after the text line starting with " / BUS_DATA".

[0141] If a text line begins with the string " / CHANGES\", it indicates that the text line stores control statements used to modify network data. For the string before the backslash "\", ignore spaces and split by commas. Search for a substring starting with "FILE=". If it does, and the substring to the right of "FILE=" is not "*", it means the modified data is stored in a separate text file and the substring to the right of "FILE=" represents the file name. Otherwise, the corresponding modified data is after the text line starting with " / CHANGES\".

[0142] (1.3) For each line of text storing network data, process it as follows:

[0143] When the text line stores one of the following data types: AC node parameters, AC node supplementary data, DC node parameters, DC node supplementary data, switchable reactance / capacitor bank parameters, or modular UPFC parallel terminal parameters, the node feature identifier is obtained from the text line. If the node feature identifier is in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1), the node number is obtained; otherwise, the hash table is updated and the node number is obtained in the manner described in step (1.1.1). If the node number is the key in the hash table storing the correspondence between node numbers and text line information in step (1.1.2), the tuple consisting of the data type of the text line identifier, the data modification identifier in the text line, and the text line number is used as the text line information, and the text line information is added to the value corresponding to the key. If not, the node number is used as the key, and the list containing only text line information is used as the value, and added to the hash table storing the correspondence between node numbers and text line information in step (1.1.2).

[0144] When the text line stores AC or DC node parameters, the partition name is retrieved from the text line. The node number and partition name are added as key-value pairs to the hash table storing the correspondence between node numbers and partition names in step (1.1.3). Then, in the hash table used in step (1.1.3) to store the correspondence between partition names and node number lists, the existence of the partition name is checked. If it does not exist, the partition name is added as the key and the list containing only node numbers is added as the value to the hash table used in step (1.1.3) to store the correspondence between partition names and node number lists. If it exists, the node number is added to the value corresponding to the partition name. When the text line... When storing AC node parameters or DC node parameters, the owner name is also obtained from the text line. The node number and owner name are added as key-value pairs to the hash table storing the correspondence between node numbers and owner names in step (1.1.3). Then, in the hash table used in step (1.1.3) to store the correspondence between the owner name and the list of node numbers, it is checked whether the owner name exists. If it does not exist, the owner name is added as the key and the list containing only node numbers is added as the value to the hash table used in step (1.1.3) to store the correspondence between the owner name and the list of node numbers. If it exists, the node number is added to the value corresponding to the owner name.

[0145] When the text line stores various AC line parameters, the AC line types include symmetrical lines and asymmetrical lines. The feature identifiers of the two end nodes are obtained from the text line. If the node feature identifiers are in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1), then the node number is obtained; otherwise, the hash table is updated as in step (1.1.1) to obtain the node number. The parallel loop identifier is obtained from the text line. If the line feature identifier formed by the two end node numbers and the parallel loop identifier is not in the hash table storing the correspondence between AC line feature identifiers and text line information in step (1.1.4), then the line feature identifier is used as the key. If the text line stores symmetrical AC line parameters... Furthermore, the per-unit reactance value is obtained from the corresponding column of the text line. If the per-unit reactance value is less than or equal to the set threshold, the AC line corresponding to the text line is regarded as a small switch branch. The tuple consisting of the line segment number, small switch branch identifier, data modification identifier in the text line, and text line number obtained from the text line is used as text line information and added to an empty list. The list is used as the value. The key-value pair is added to the hash table storing the correspondence between AC line feature identifier and text line information in step (1.1.4). If the line feature identifier is a key that already exists in the hash table storing the correspondence between AC line feature identifier and text line information in step (1.1.4), the text line information is added to the value corresponding to the key.

[0146] When the text line stores AC line high-resistance parameters, the feature identifiers of the two end nodes are obtained from the text line. If the node feature identifiers are stored in the hash table corresponding to the node feature identifiers and node numbers in step (1.1.1), the node number is obtained. Otherwise, the hash table is updated and the node number is obtained in the manner of step (1.1.1). The parallel circuit identifier is obtained from the text line. The feature identifier formed by the two end node numbers and the parallel circuit identifier is used as the key. The tuple formed by the data modification identifier and the text line number in the text line is used as the text line information. The list containing only the text line information is used as the value. The key-value pair is added to the hash table corresponding to the AC line high-resistance feature identifiers and the text line number in step (1.1.4).

[0147] When the text line stores the line complement parameters that can be quickly adjusted, the feature identifiers of the two end nodes are obtained from the text line. If the node feature identifiers are in the hash table that stores the correspondence between the node feature identifiers and the node numbers in step (1.1.1), the node number is obtained. Otherwise, the hash table is updated and the node number is obtained in the manner of step (1.1.1). The parallel loop identifier is obtained from the text line. The line feature identifier formed by the two end node numbers and the parallel loop identifier is used as the key. The tuple formed by the data modification identifier and the text line number in the text line is used as the text line information. The list containing only the text line information is used as the value. The key-value pair is added to the hash table that stores the correspondence between the line complement feature identifiers that can be quickly adjusted and the text line information in step (1.1.5).

[0148] When the text line stores transformer / phase shifter parameters, the feature identifiers of the two end nodes are obtained from the text line. If the node feature identifiers are stored in the hash table corresponding to the node feature identifiers and node numbers in step (1.1.1), the node number is obtained. Otherwise, the hash table is updated and the node number is obtained in the manner of step (1.1.1). The parallel circuit identifier is obtained from the text line. The tuple consisting of the node numbers at both ends and the parallel circuit identifier is used as the key. The tuple consisting of the data modification identifier in the text line and the text line number is used as the text line information. The list containing only the text line information is used as the value. The key-value pair is added to the hash table corresponding to the transformer / phase shifter feature identifiers and text line information in step (1.1.6).

[0149] When the text line stores the control parameters of the load-regulating transformer / phase shifter, the feature identifiers of the two end nodes are obtained from the text line. If the node feature identifier is in the hash table that stores the correspondence between the node feature identifier and the node number in step (1.1.1), the node number is obtained. Otherwise, the hash table is updated and the node number is obtained in the manner of step (1.1.1). The tuple formed by the node numbers of the two end nodes is used as the key, the tuple formed by the data modification identifier and the text line number in the text line is used as the text line information, and the list containing only the text line information is used as the value. The key-value pair is added to the hash table that stores the correspondence between the feature identifiers of the load-regulating transformer / phase shifter control parameters and the text line information in step (1.1.7).

[0150] When the text line stores the serial terminal parameters of the modular UPFC, the feature identifiers of the two end nodes are obtained from the text line. If the node feature identifiers are in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1), then the node number is obtained; otherwise, the hash table is updated and the node number is obtained in the manner described in step (1.1.1). The parallel loop identifier is obtained from the text line. If the feature identifier formed by the node numbers of the two end nodes and the parallel loop identifier is not in the hash table storing the correspondence between the modular UPFC serial terminal feature identifiers and the text line number in step (1.1.8), then the feature identifier is not obtained. The feature identifier is used as the key, and the tuple consisting of the text line number and the value zero (the default value of the text line number storing the supplementary data of the modular UPFC serial terminal) is used as the value. The key-value pair is added to the hash table storing the correspondence between the feature identifier and the text line number of the modular UPFC serial terminal in step (1.1.8). If the line feature identifier is a key that already exists in the hash table storing the correspondence between the feature identifier and the text line number of the modular UPFC serial terminal in step (1.1.8), then the default value of the text line number of the modular UPFC serial terminal parameter in the value corresponding to the key is modified to the text line number.

[0151] When the text line stores supplementary data for the modular UPFC serial terminals, the feature identifiers of the two end nodes are obtained from the text line. If the node feature identifiers are in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1), then the node number is obtained; otherwise, the hash table is updated and the node number is obtained as in step (1.1.1). The parallel loop identifier is obtained from the text line. If the feature identifier formed by the two end node numbers and the parallel loop identifier is not in the hash table storing the correspondence between the modular UPFC serial terminal feature identifiers and the text line number in step (1.1.8), then... The feature identifier is used as the key, and the tuple consisting of the value zero (the default value of the text line number storing the modular UPFC serial terminal parameter) and the text line number is used as the value. The key-value pair is added to the hash table storing the correspondence between the feature identifier and the text line number of the modular UPFC serial terminal in step (1.1.8). If the line feature identifier is a key that already exists in the hash table storing the correspondence between the feature identifier and the text line number of the modular UPFC serial terminal in step (1.1.8), then the default value of the text line number representing the supplementary data of the modular UPFC serial terminal in the value corresponding to the key is modified to the text line number.

[0152] When the text line stores various DC line parameters, the types of DC lines include two-terminal DC lines, multi-terminal DC lines, flexible DC lines, and LCC DC lines. The feature identifiers of the two-terminal nodes are obtained from the text line. If the node feature identifier is stored in the hash table corresponding to the node feature identifier and the node number in step (1.1.1), the node number is obtained. Otherwise, the hash table is updated and the node number is obtained in the manner of step (1.1.1). The tuple composed of the node number is used as the key, the tuple composed of the data modification identifier and the text line number in the text line is used as the text line information, and the list containing only the text line information is used as the value. The key-value pair is added to the hash table corresponding to the DC line parameter feature identifier and the text line number in step (1.1.9).

[0153] When the text line stores LCC DC control parameters, the feature identifiers of the rectifier low-side converter node, the rectifier high-side converter node, the inverter low-side converter node, and the inverter high-side converter node are obtained from the text line. If the feature identifier of any node is stored in the hash table corresponding to the node feature identifier and the node number in step (1.1.1), the node number is obtained. Otherwise, the hash table is updated and the node number is obtained in the manner of step (1.1.1). The tuple formed by the node number is used as the key, and the text line number is used as the value. The key-value pair is added to the hash table corresponding to the LCC DC control parameter feature identifier and the text line number in step (1.1.9).

[0154] When a text line stores region control data, the text line is ignored.

[0155] (1.4) Establish a data structure for storing modified data, specifically by performing the following sub-steps:

[0156] (1.4.1) For node parameters, create a list to store the numbers of newly added nodes and a list to store the numbers of deleted nodes. The elements in the list are node numbers.

[0157] (1.4.2) Create a hash table to store the correspondence between the line number of the text line and the partition name when the power generation / load percentage is modified by partition. The key is the line number of the text line in its file and the value is the partition name. Create a hash table to store the correspondence between the line number of the text line and the list of specified partition names when the power generation / load percentage is modified by specified partition. The key is the line number of the text line in its file and the value is a list of partition names.

[0158] (1.4.3) Create a hash table to store the correspondence between the line number of the text line and the owner name when the power generation / load percentage is modified by the owner. The key is the line number of the text line in the file to which it belongs, and the value is the owner name. Create a hash table to store the correspondence between the line number of the text line and the list of the specified owner names when the power generation / load percentage is modified by the specified owner. The key is the line number of the text line in the file to which it belongs, and the value is a list of owner names.

[0159] (1.5) For each text line storing modified data, process it as follows:

[0160] When the text line stores new AC node parameters, supplementary AC node data, DC node parameters, supplementary DC node data, or switchable reactance / capacitor bank parameters, the node feature identifier is obtained from the text line. If the node feature identifier is in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1), the node number is obtained; otherwise, the hash table is updated and the node number is obtained as in step (1.1.1). If the node number is a key in the hash table storing the correspondence between node numbers and text line information in step (1.1.2), the data type of the text line identifier and the data modification flag in the text line are changed. The tuple consisting of the identifier and the text line number serves as the text line information. The text feature identifier is added to the value corresponding to the key. If not, the node number is used as the key, and the list containing only text line information is used as the value, added to the hash table storing the correspondence between node numbers and text line information in step (1.1.2). When the text line stores new AC node parameters or DC node parameters, if the node number is in the list of deleted node numbers stored in step (1.4.1), the node number is deleted from the list of deleted node numbers stored in step (1.4.1); otherwise, it is added to the list of new node numbers stored in step (1.4.1). When this line stores newly added AC or DC node parameters, it also retrieves the partition name from the text line, adds the node number and partition name as key-value pairs to the hash table storing the correspondence between node numbers and partition names in step (1.1.3), and then checks whether the partition name exists in the hash table used in step (1.1.3) to store the correspondence between partition names and node number lists. If it does not exist, it adds the partition name as the key and the list containing only node numbers as the value to the hash table used in step (1.1.3) to store the correspondence between partition names and node number lists. If it exists, it adds the node number to the value corresponding to the partition name; when the text line... When storing AC node parameters or DC node parameters, the owner name is also obtained from the text line. The node number and owner name are added as key-value pairs to the hash table storing the correspondence between node numbers and owner names in step (1.1.3). Then, in the hash table used in step (1.1.3) to store the correspondence between the owner name and the list of node numbers, it is checked whether the owner name exists. If it does not exist, the owner name is added as the key and the list containing only node numbers is added as the value to the hash table used in step (1.1.3) to store the correspondence between the owner name and the list of node numbers. If it exists, the node number is added to the value corresponding to the owner name.

[0161] When the content stored in the text line is the deletion of AC node parameters, or supplementary data for AC nodes, or DC node parameters, or supplementary data for DC nodes, or parameters of switchable reactance / capacitor banks, the node feature identifier is obtained from the text line. Based on the node feature identifier, the corresponding node number is found in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1). Then, based on the node number, the value corresponding to the node number is found in the hash table storing the correspondence between node numbers and text line information in step (1.1.2). The tuple consisting of the data type of the text line identifier, the data modification identifier in the text line, and the text line number is used as the text line information. The text feature identifier is added to the value corresponding to the node number. When the content stored in the text line is the deletion of AC node parameters or DC node parameters, if the node number is in the list of newly added node numbers stored in step (1.5), the node number is deleted from the list of newly added node numbers stored in step (1.5). Otherwise, the node number is added to the list of deleted node numbers stored in step (1.5).

[0162] When the content stored in the text line is the recovery of deleted AC node parameters, or supplementary data for AC nodes, or DC node parameters, or supplementary data for DC nodes, or parameters of switchable reactance / capacitor banks, the node feature identifier is obtained from the text line. Based on the node feature identifier, the corresponding node number is found in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1). Then, based on the node number, the value corresponding to the node number is found in the hash table storing the correspondence between node numbers and text line information in step (1.1.2). The tuple consisting of the data type of the text line identifier, the data modification identifier in the text line, and the text line number is used as the text line information. The text feature identifier is added to the value corresponding to the node number. When the content stored in the text line is the recovery of deleted AC node parameters or DC node parameters, if the node number is in the list of deleted node numbers stored in step (1.5), the node number is deleted from the list of deleted node numbers. Otherwise, the node number is added to the list of newly added node numbers stored in step (1.5).

[0163] When the text line stores information about modifying AC node parameters, supplementing AC node data, DC node parameters, or switchable reactance / capacitor bank parameters, the node feature identifier is retrieved from the text line. Based on the node feature identifier, the corresponding node number is found in the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1). Then, based on the node number, the value corresponding to the node number is found in the hash table storing the correspondence between node numbers and text line information in step (1.1.2). The tuple consisting of the data type of the text line identifier, the data modification identifier in the text line, and the text line number is used as the text line information, and the text feature identifier is added to the value corresponding to the node number. When the text line stores information about modifying AC node parameters or DC node parameters, the partition name and owner name are retrieved from the text line and used for storage in step (1.1.3) based on the node number. The initial partition name is queried from the hash table that corresponds to the node number and partition name. If the initial partition name found is inconsistent with the partition name in the text line, the hash table used in step (1.1.3) to store the correspondence between the node number and partition name is updated, and the original partition name corresponding to the node number is replaced with the partition name in the text line. Then the hash table used in step (1.1.3) to store the correspondence between the partition name and the list of node numbers is updated again. During the update, the node number is deleted from the list of node numbers corresponding to the original partition name. If the partition name in the text line does not exist in the hash table, the partition name in the text line is used as the key and the list containing only node numbers is used as the value. The key-value pair is added to the hash table. Otherwise, the node number is added to the value corresponding to the partition name in the text line. The hash table used in step (1.1.3) to store the correspondence between the node number and the owner name and the hash table used to store the correspondence between the owner name and the list of node numbers are processed in a similar way.

[0164] When the content stored in the text line is one of the following types of data: AC line high-resistance parameters, quickly adjustable line series compensation parameters, transformer / phase shifter parameters, on-load voltage regulating transformer / phase shifter control parameters, or DC line parameters, the modification includes adding data, deleting data, correcting data, and restoring deleted data. The branch feature identifier is determined based on the hash table corresponding to the node feature identifier and node number stored in step (1.1.1), and text line information is established according to the parameter type. Then, the relationship between the branch feature identifier and text line information stored in step (1.1) is queried. For a hash table corresponding to the relationship, if the branch feature identifier is the key in the hash table, then the text line information is added to the value corresponding to the key; otherwise, the branch feature identifier is used as the key, and the list consisting only of text line information is used as the value, and the key-value pair is added to the hash table. When the content stored in the text line is the addition or modification of AC line parameters, it is also handled in a similar way. When the content stored in the text line is the deletion or restoration of deleted AC line parameters, and the segment number in the text line is not zero and not blank, and the parallel circuit identifier is not "*" and not blank, it is also handled in a similar way.

[0165] When the text line stores information about deleting or restoring deleted AC line parameters, if the parallel circuit identifier in the text line is "*" or blank, it indicates that all parallel AC lines have been deleted or restored. The line feature identifier is determined based on the hash table that stores the correspondence between node feature identifiers and node numbers in step (1.1.1). The value corresponding to the line feature identifier is found in the hash table that stores the correspondence between branch feature identifiers and text line information in step (1.1). All text line information in the value is copied, and the data modification identifier in the copied text line information is changed to a deletion identifier or a restore deletion identifier. The copied text line information is then added to the line. If the segment number in the text line is zero or blank, it indicates that the AC line composed of each segment line connected in series has been completely deleted or completely restored. The line feature identifier is determined according to the hash table that stores the correspondence between the node feature identifier and the node number in step (1.1.1). The value corresponding to the line feature identifier is found in the hash table that stores the correspondence between the branch feature identifier and the text line information in step (1.1). All text line information that is the same as the parallel circuit identifier in the text line is copied. The data modification identifier in the copied text line information is changed to the deletion identifier or the restoration deletion identifier. The copied text line information is then added to the value corresponding to the line feature identifier.

[0166] When the content stored in the text line is the modification of the generation / load percentage by partition, the line number of the text line in its file is used as the key, the partition name is obtained from the text line and used as the value, and the key-value pair is added to the hash table storing the correspondence between the text line number and the partition name when the generation / load percentage is modified by partition in step (1.4.2); when the content stored in the text line is the modification of the generation / load percentage by a specified partition, the line number of the text line in its file is used as the key, all partition names are obtained from the text line and the list constructed from all partition names is used as the value, and the key-value pair is added to the hash table storing the correspondence between the text line number and the specified partition name when the generation / load percentage is modified by a specified partition in step (1.4.2).

[0167] When the content stored in the text line is the percentage of power generation / load modified by owner, the line number of the text line in the file is used as the key, the owner name is retrieved from the text line and used as the value, and the key-value pair is added to the hash table storing the correspondence between the line number of the text line and the owner name when the percentage of power generation / load is modified by owner in step (1.4.3); when the content stored in the text line is the percentage of power generation / load modified by a specific owner, the line number of the text line in the file is used as the key, all owner names are retrieved from the text line and the list constructed from the owner names is used as the value, and the key-value pair is added to the hash table storing the correspondence between the line number of the text line and the specified owner name when the percentage of power generation / load is modified by a specified owner in step (1.4.3).

[0168] (2) Based on the topology information required to divide the black start subnet in the black start scheme, conduct electrical topology connection analysis.

[0169] The topology information required for dividing the black-start subnets in the black-start scheme includes external starting power source information, AC node information of the inter-provincial AC tie lines of each subnet of the target power grid on the target power grid side, other external AC tie line information of the target power grid, and tie line information between each black-start subnet in the target power grid. External starting power source information is usually described by the inter-provincial AC tie line information of each subnet of the target power grid. The information of each AC tie line is described in PSD-BPA format with the node names at both ends of the line, the node reference voltage, and the parallel circuit identifier. For parallel tie lines, only the information of one line needs to be provided. The AC node information connected to the inter-provincial AC tie lines and on the target power grid side is represented by the node name and the node reference voltage in PSD-BPA format.

[0170] Based on the topology information required to divide the black-start subnet in the black-start scheme, the electrical topology connection analysis includes the following steps:

[0171] (2.1): Create a hash table to store the relationship between node numbers and new node numbers, with node numbers as keys and new node numbers as values;

[0172] (2.2): Create a hash table to store the relationship between the new node number and the list of node numbers, where the new node number is the key and the list of node numbers is the value;

[0173] (2.3): Traverse the hash table storing the correspondence between AC line feature identifiers and text line information in step (1.1.4), and obtain the connected subgraph describing the AC small switch branch through topological analysis; for each connected subgraph, if there is more than one vertex in the connected subgraph, then all nodes corresponding to the connected subgraph are regarded as 1 node, and a new number is created for all nodes corresponding to the connected subgraph, and this number is different from all node numbers, and the hash table in steps (2.1) and (2.2) is updated with the node number and the new node number;

[0174] In step (2.3), the specific method for obtaining the connected subgraph describing the AC small switch branch is as follows: an undirected graph is established, and the hash table storing the correspondence between AC line feature identifiers and text line information in step (1.1.4) is traversed. The numbers of the nodes at both ends of the line are obtained from the feature identifiers. If the numbers of the nodes at both ends are not in the list of deleted node numbers stored in step (1.4.1), then for the text line information corresponding to each feature identifier, the segment number, the small switch branch identifier, and the data modification identifier are used to determine whether the corresponding AC line is a valid small switch branch. If so, the numbers of the nodes at both ends are added to the undirected graph as vertices, and an edge is added to these two vertices. Then, connectivity analysis is performed on the undirected graph to obtain all the connected subgraphs.

[0175] Step (2.4): Establish a set of text line numbers that are unrelated to the external network equivalent simulation data. The text lines are stored in the file where the network data was stored in step (1), and the data stored in the text lines must be set to invalid when constructing the external network equivalent simulation data;

[0176] Step (2.5): For each black start subnet of the target power grid, establish a set of text line numbers for simulation analysis of the grid restoration stage. In the network data file of step (1), the branches and nodes represented by the text lines belong to each black start subnet in terms of electrical topology, and the branch and node data do not need to be modified. For each black start subnet of the target power grid, establish a set of text line numbers for simulation analysis of the load restoration stage. In the network data file of step (1), the branches and nodes represented by the text lines belong to each black start subnet in terms of electrical topology, and the branch and node data do not need to be modified.

[0177] Step (2.6): For each black start subnet of the target power grid, establish a set of node numbers whose node parameters need to be modified when constructing the simulation data of the black start subnet, a set of text line information corresponding to the nodes that need to be modified, a set storing the partition name to which the nodes in the black start subnet belong, and a set storing the owner name to which the nodes in the black start subnet belong. The text line information is a tuple composed of the text line number and the data type of the text line identifier.

[0178] Step (2.7): Traverse the hash table storing the characteristic identifiers and text line information of a certain type of AC series branch in step (1.1). The types of AC branches include AC lines, transformers / phase shifters, UPFC series terminals and line series compensation that can be quickly adjusted. Combine the topology information required to divide the black start subnet in the black start scheme, the hash tables in steps (2.1) and (2.2), and perform AC topology analysis on the network data and the power grid represented by the modified data to obtain the AC connectivity subgraph describing the external network and the connectivity subgraph corresponding to each black start subnet of the target power grid in the load recovery stage and the grid recovery stage. Update the data structure in steps (2.4), (2.5) and (2.6).

[0179] Step (2.8): Establish a set of node numbers whose node parameters need to be modified when constructing external network equivalent simulation data, and a set of text line information corresponding to the nodes that need to be modified. The text line information is a tuple composed of text line number and the data type of text line identifier.

[0180] Step (2.9): Traverse the hash table storing DC line feature identifiers and text line information in step (1.1.9), perform DC topology analysis on the network data and the power grid represented by the modified data, update the connected subgraphs describing the external network and each black start subnet in step (2.7), and update the data structures in steps (2.4), (2.5) and (2.8).

[0181] The nodes that need modification mentioned in steps (2.6) and (2.8) refer to the DC nodes stored in the DC node parameter card of the original power flow data file describing the typical operating mode. According to the DC node data definition method of PSD-BPA, it is both the endpoint of the DC line and the interface node connecting to the AC power grid. If the target power grid and the external network are connected via DC under the typical operating mode, the corresponding DC line needs to be set to the off state during the black start of the target power grid. When establishing simulation data for black start, if the DC node is not connected to other DC lines and is not connected to a converter transformer, the data type of the DC node needs to be changed to a normal AC node type, and the corresponding node parameters need to be corrected to the default values. If the above corrections are not made, PSD-BPA will prompt that there are data errors when performing calculations.

[0182] (2.7) Conduct communication topology analysis on network data, specifically including the following sub-steps:

[0183] (2.7.1) Construct an undirected graph describing the electrical topology of an AC power grid. The vertices of the graph are node numbers or new numbers. The edges between two vertices represent AC series branches, and the edges connecting vertices themselves represent AC small switch branches. The attributes of the edges include branch feature identifier, branch data type, and corresponding text line number.

[0184] (2.7.2) Read the topology information required for dividing the black start subnet in the black start scheme, and obtain the line number and parallel circuit identifier of each AC tie line in the text line in the topology information; according to the hash table storing the correspondence between AC node feature identifier and node number in step (1.1.1), obtain the node number of each AC tie line at both ends in the topology information, and the node number of the inter-provincial AC tie line of each subnet of the target power grid in the topology information on the target power grid side;

[0185] (2.7.3) Traverse the hash table storing the feature identifiers and text line information of a certain type of AC series branch in step (1.1). The types of AC branches include AC lines, transformers / phase shifters, UPFC series terminals, and line series complements that can be quickly adjusted. Obtain the node numbers at both ends of the branch. If the node numbers at both ends are not in the list of deleted node numbers stored in step (1.4.1), search for the modification code in the value corresponding to the key to determine whether the branch is in a valid state or a deleted state. If valid, further search the hash table storing the relationship between the node numbers and the new node numbers in step (2.1). If the node number does not have a corresponding new number, add the node number as a vertex to the undirected graph in step (2.7.1). If the node number has a corresponding new number, add the new node number as a vertex to the undirected graph in step (2.7.1). If the branch is an AC small switch branch, the vertices representing the nodes at both ends of the branch are the same vertex. Add a self-loop to the corresponding vertex. Otherwise, add an edge to the two vertices representing the nodes at both ends of the branch.

[0186] (2.7.4) For each AC link in the topology information of step (2.7.2), check whether the nodes at both ends of the AC link have new numbers in the hash table storing the relationship between AC node numbers and new numbers in step (2.1). If the node number does not have a corresponding new number, then the node number is used as a vertex; if the node number has a corresponding new number, then the new number of the node is used as a vertex. Find all the edges between the two vertices corresponding to each link in the undirected graph of step (2.7.1), and store the AC branch text line numbers corresponding to these edges into the set of text line numbers that are unrelated to the external network equivalent simulation data stored in step (2.4). Then delete these edges in the undirected graph; for each black start subnet, add the text line number corresponding to the inter-provincial communication link of the start subnet to the text line number set for load recovery stage analysis in step (2.5) and the text line number set for network structure recovery stage analysis. According to the number of the link on the external network side node, find the text line number corresponding to the external network side node parameter in the hash table used to store the correspondence between node number and text line information in step (1.1.2), and add it to the text line number set for load recovery stage analysis in step (2.5) and the text line number set for network structure recovery stage analysis.

[0187] (2.7.5) Perform connectivity analysis on the undirected graph in step (2.7.1) to obtain all connected subgraphs; based on the AC node numbers of the inter-provincial AC tie lines of each sub-network of the target power grid in step (2.7.1) and the hash table storing the relationship between the AC node numbers and the new AC node numbers in step (2.1), obtain the connected subgraphs corresponding to each black-start sub-network of the target power grid during the load recovery phase;

[0188] (2.7.6) Traverse the vertices of the connected subgraph corresponding to each black start subnet during the load recovery phase. Based on the hash table storing the correspondence between the new node number and the node number list in step (2.2), determine all the node numbers corresponding to the vertices in the graph. Then query the hash table storing the correspondence between the node number and the text line information in step (1.1.2) and add all the text line numbers corresponding to the node number to the set of text line numbers that are unrelated to the external network equivalent simulation data in step (2.4). Based on the hash table storing the correspondence between the node number and the partition name in step (1.1.3), find the partition name corresponding to the node and add the partition name to step (2.7.6). 6) In the set of partition names to which nodes belong within the storage subnet, find the list of node numbers corresponding to the partition name in the hash table used to store the correspondence between partition names and node number lists, and delete the node number corresponding to the vertex from the node number list; according to the hash table used in step (1.1.3) to store the correspondence between node numbers and owner names, find the owner name corresponding to the node, add the owner name to the set of owner names to which nodes belong within the storage subnet in step (2.6), and find the list of node numbers corresponding to the owner name in the hash table used to store the correspondence between owner names and node number lists, and delete the node number corresponding to the vertex from the node number list;

[0189] (2.7.7) For each black-start subnet, traverse the edges in the corresponding connected subgraph. Based on the edge's attributes, add the text line number corresponding to the edge to the set of text line numbers unrelated to the external network equivalent simulation data stored in step (2.4) and the set of text line numbers for load recovery stage analysis in step (2.5). If the data type of the branch corresponding to the edge is AC line parameter, then based on the branch feature identifier corresponding to the edge, search the hash table storing AC line high-resistance parameter feature identifier and text line information in step (1.1.4) to see if there is a corresponding AC line high-resistance. If so, find the corresponding text line number and add it to the set in step (2.4). The text line numbers are stored in the set of text line numbers that are unrelated to the external network equivalent simulation data and in the set of text line numbers for the load recovery stage analysis in step (2.5); if the data type of the branch corresponding to the edge is transformer / phase shifter parameters, then according to the branch feature identifier corresponding to the edge, search for a corresponding key in the hash table of the load-regulating transformer / phase shifter control parameter feature identifier and text line information stored in step (1.1.7). If there is a key, find the corresponding text line number and add the text line number to the set of text line numbers that are unrelated to the external network equivalent simulation data stored in step (2.4) and the set of text line numbers for the load recovery stage analysis in step (2.5);

[0190] (2.7.8) For each black-start subnet, a new connected subgraph for each subnet in the grid restoration stage is created by copying the connected subgraph corresponding to the load restoration stage in step (2.7.5). For cases where two or more lines are running in parallel, two or more transformers are running in parallel, or two or more phase shifters are running in parallel, only the data corresponding to one branch is retained in the connected subgraph. The specific steps are as follows: traverse the edges connecting two vertices in the newly created connected subgraph. According to the edge attributes, if there are multiple parallel edges representing AC lines, only one edge is retained and the others are deleted; if there are multiple parallel edges representing transformers, only one edge is retained and the others are deleted. The text line number corresponding to the retained edge is added to the text line number set for grid restoration stage analysis in step (2.5); if there are multiple parallel edges representing phase shifters, the method of processing parallel edges representing transformers is used as described above, and the corresponding text line number is added to the text line number set for grid restoration stage analysis in step (2.5).

[0191] (2.7.9) For the connected subgraphs of each black-start subnet during the grid restoration phase in step (2.7.8), for cases where two or more three-winding transformers are operating in parallel at both ends, only the data corresponding to one of the three-winding transformers is retained in the connected subgraph. Specifically, in the connected subgraph, all vertices with a degree of 3 and whose connecting edges represent transformers are found. The three adjacent nodes connected to each vertex are stored as a tuple in a temporary list. Then, those tuples in the temporary list containing two identical nodes are found. For multiple tuples containing two identical nodes, in the connected subgraph, the vertices with a degree of 3 and whose connecting edges represent transformers corresponding to one tuple are retained, and the vertices with a degree of 3 and whose connecting edges represent transformers, as well as the edges connected to the vertices, are deleted from the connected subgraph. Then, for each black-start subnet, the line number of the text corresponding to the vertex in the connected subgraph is added to the step... In step (2.5), in the set of text line numbers for the analysis of the grid restoration stage, traverse the edges connecting two vertices in the connected subgraph and add the text line numbers corresponding to the edges to the set of text line numbers for the analysis of the grid restoration stage in step (2.5). If the edge represents an AC line, also search for the corresponding AC line high-resistance parameter feature identifier and text line information in the hash table storing AC line high-resistance parameter feature identifier and text line information in step (1.1.4). If there is one, find the corresponding text line number and add the text line number to the set of text line numbers for the analysis of the grid restoration stage in step (2.5). If the edge represents a transformer, search for the corresponding key in the hash table storing load-regulating transformer / phase shifter control parameter feature identifier and text line information in step (1.1.7). If there is one, find the corresponding text line number and add the text line number to the set of text line numbers for the analysis of the grid restoration stage in step (2.5).

[0192] Combination Figure 3 This will illustrate the implementation of step (2.7.9). Figure 3 The equivalent circuit diagram of two three-winding transformers operating in parallel is shown. In PSD-BPA, an actual three-winding transformer is simulated by three two-winding transformers; that is, one three-winding transformer corresponds to three two-winding transformer data cards (three T cards). Figure 3 In the diagram, T1, T2, and T3 represent two-winding transformers simulating a three-winding transformer, with the common node of T1, T2, and T3 designated as "center point 1." T4, T5, and T6 represent two-winding transformers simulating another three-winding transformer, with the common node of T4, T5, and T6 designated as "center point 2." The 500kV sides of T1 and T4 are connected to the same node, and the 220kV sides of T3 and T5 are connected to the same node, indicating that the two simulated three-winding transformers are operating in parallel. Figure 3 It can be seen that for the common nodes "center point 1" and "center point 2" of the three two-winding transformers simulating a three-winding transformer, they are all connected to three edges formed by transformers, and the degree is 3. When running in parallel, two of the three adjacent nodes of "center point 1" and "center point 2" are the same, that is, the "500kV node" and "220kV node" in the figure.

[0193] When generating simulation data describing the restoration of power supply to the power grid via a single AC line and a single transformer (i.e., simulation data corresponding to the power grid restoration phase), in order to Figure 3 For example, it is to start from Figure 3 Remove one of the three-winding transformers simulated by three two-winding transformers. As can be seen from the above analysis, the basic idea of ​​step (2.7.9) is to find all common nodes similar to "center point 1" and "center point 2", and then find the text line corresponding to the transformers running in parallel based on the characteristic that the two adjacent nodes of these common nodes are the same when running in parallel.

[0194] (2.9) Specifically, it includes the following sub-steps:

[0195] (2.9.1) Construct an undirected graph describing the electrical topology of a DC power grid. The vertices of the graph are node numbers or new numbers, and the edges represent DC branches. The attributes of the edges include branch feature identifier, branch data type, and corresponding text line number.

[0196] (2.9.2) Traverse the hash table storing DC line feature identifiers and text line information in step (1.1.9) to obtain the node numbers at both ends of the branch and the text line number corresponding to the branch. If the node numbers at both ends are not in the list storing the deleted node numbers in step (1.4.1), then look up the modification code in the value corresponding to the key to determine whether the branch is in a valid state or a deleted state. If valid, add both node numbers as vertices to the undirected graph in step (2.7.6) and add edges to these two vertices.

[0197] (2.9.3) Traverse the undirected graph of step (2.9.1) and check whether each vertex in the graph is in the connected subgraph corresponding to each black start sub-network of the target power grid in step (2.7.5). If it is, delete the edge connected to the vertex in the undirected graph of step (2.9.1) and add the text line number corresponding to the edge to the set of text line numbers that are unrelated to the external network equivalent simulation data stored in step (2.4).

[0198] (2.9.4) Traverse the undirected graph of step (2.9.1). When the degree of a vertex traversed in the graph is zero, obtain the node type corresponding to the vertex through the hash table storing the correspondence between node number and text line information in step (1.1.2), and process it as follows:

[0199] If the node type corresponding to the vertex is a flexible DC node or an LCC DC node, and there is a corresponding vertex in the connected subgraph corresponding to the black start subnet in step (2.7.5), add the corresponding node number to the set of node numbers for which node parameters need to be modified when constructing the black start subnet simulation data in step (2.6). Query the hash table storing the correspondence between node numbers and text line information in step (1.1.2) to obtain all text line information corresponding to the node number. Add the tuple consisting of the text line number and the data type of the text line identifier to the set of text line information corresponding to the node for which modification is required when constructing the black start subnet simulation data in step (2.6). If the vertex is an LCC DC node, in the hash table storing the correspondence between the LCC DC control parameter feature identifier and the text line number in step (1.1.9), check whether the feature identifier contains a node number. If so, add the tuple consisting of the corresponding text line number and the data type of the text line identifier to the set of text line information corresponding to the node for which modification is required when constructing the black start subnet simulation data in step (2.6).

[0200] If the node type corresponding to the vertex is a flexible DC node or an LCC DC node, and there is no corresponding vertex in the connected subgraph corresponding to the black start subnet in step (2.7.5), add the corresponding node number to the set of node numbers whose node parameters need to be modified when constructing the equivalent simulation data of the external network in step (2.8). Query the hash table storing the correspondence between node numbers and text line information in step (1.1.2) to obtain all text line information corresponding to the node number. Add the tuple consisting of the text line number and the data type of the text line identifier to the set of text line information corresponding to the node that needs to be modified when constructing the equivalent simulation data of the external network in step (2.8). If the vertex is an LCC DC node, in the hash table storing the correspondence between the feature identifier and the text line number of the LCC DC control parameter in step (1.1.9), check whether the feature identifier contains a node number. If so, add the tuple consisting of the corresponding text line number and the data type of the text line identifier to the set of text line information corresponding to the node that needs to be modified when constructing the equivalent simulation data of the external network in step (2.8).

[0201] If the node type corresponding to the vertex is a two-end DC node or a multi-end DC node, and there is no corresponding vertex in the connected subgraph corresponding to the black start subnet in step (2.7.5), then in step (2.7.1), the connected subgraph where the vertex is located is searched in the undirected graph, the vertex and its connected edges are deleted from the connected subgraph, and the text line numbers corresponding to the deleted vertex and its connected edges are added to the set of text line numbers that are unrelated to the external network equivalent simulation data in step (2.4).

[0202] If the node type corresponding to the vertex is a two-end DC node or a multi-end DC node, and there is a corresponding vertex in the connected subgraph corresponding to the black start subnet in step (2.7.5), then delete the vertex and its connected edges in the connected subgraph, and delete the text line numbers corresponding to the vertex and its connected edges from the text line number set for load recovery stage analysis in step (2.5) and the text line number set for network recovery stage analysis.

[0203] (3) Generate power flow simulation data files for calculating the equivalent parameters of the external network, and generate power flow simulation data files for each black start subnet of the target power grid that are suitable for the analysis of the grid restoration stage and the analysis of the load restoration stage.

[0204] Generate power flow simulation data files for calculating equivalent parameters of the external network, and generate power flow simulation data files suitable for network restoration phase analysis and load restoration phase analysis for each black-start subnetwork of the target power grid. The specific steps include:

[0205] (3.1) Create a new power flow data file for calculating the equivalent parameters of the external network; create a new power flow data file for each black-start subnet of the target power grid, suitable for analyzing the grid restoration phase; create a new power flow data file for each black-start subnet of the target power grid, suitable for analyzing the load restoration phase.

[0206] (3.2) For each file in step (3.1), write control statements such as specifying the start of power flow, setting the system baseline capacity, and specifying the output of power flow results, line by line. The system baseline capacity is taken from the baseline capacity saved in step (1.2).

[0207] (3.3) Read the network data from step (1.2) line by line and process it as follows:

[0208] When the text line number needs to be modified when constructing the external network equivalent simulation data in step (2.8), if the data type of the text line identifier is a node parameter, then the text line content is modified to the default value of the AC node parameter, and then the text line content is written into the power flow data file used to calculate the external network equivalent parameters in step (3.1), and then the next line is read.

[0209] When the text line number is not in the set of text line numbers that are not related to the external network equivalent simulation data stored in step (2.4), the text line content is written to the power flow data file used to calculate the external network equivalent parameters in step (3.1), and then the next line is read.

[0210] When the text line number is in the set of text line numbers for the load recovery phase analysis corresponding to a certain black start subnet in step (2.5), the text line content is written into the power flow data file for the load recovery phase analysis of that subnet in step (3.1); if the text line is not in the set of text line numbers for the network structure recovery phase analysis of that subnet in step (2.5), the text line content is copied and a comment character is added at the beginning of the text line before writing it into the power flow data file for the network structure recovery phase analysis of that subnet in step (3.1); if the text line is in the set of text line numbers for the network structure recovery phase analysis of that subnet in step (2.5), the text line content is written into the power flow data file for the network structure recovery phase analysis of that subnet in step (3.1); then proceed to the next line to read;

[0211] When the text line number needs to be modified in the text line information set corresponding to the node when constructing simulation data of a certain black start subnet in step (2.6), if the data type of the text line identifier is node parameter, modify the text line content to the default value of the AC node parameter, and then write the text line content into the power flow data file for the subnet structure recovery stage and load recovery system analysis in step (3.1), and then read the next line.

[0212] (3.4) Write control statements line by line to specify the data saving location. The default data saving location is the new file in step (3.1). Then read the data modified in step (1.2) line by line and process it as follows:

[0213] When the text line number is stored in the hash table corresponding to the partition name when the power generation / load percentage is modified by partition in step (1.4.2), check the hash table corresponding to the partition name and the node number list in step (1.1.3) according to the partition name. If the corresponding node number list is not empty, write the text line into the power flow data file used to calculate the external network equivalent parameters in step (3.1); for the set of partition names of each node in the black start subnet stored in step (2.6), check whether the partition name is in the set. If it is, write the text line into the power flow data file for the analysis of the subnet network structure recovery stage and load recovery stage in step (3.1) respectively; then move to the next line to read.

[0214] When the text line number is stored in the hash table corresponding to the generation / load percentage by specified partition in step (1.4.2), each partition name in the partition name list is traversed. Based on the partition name, the hash table corresponding to the partition name and node number list stored in step (1.1.3) is checked. If the corresponding node number list is not empty, the partition name is saved in a temporary list. After traversing the partition name list, if the temporary list is not empty, the text line content is copied and the partition name stored in the text line is modified to the element existing in the temporary list. Then, the modified text line content is written to step (3). 1) In the power flow data file used to calculate the equivalent parameters of the external network; a temporary list is created for each black-start subnet. The partition name in the partition name list is checked in turn to see if it is in the set of partition names of the nodes in the subnet stored in step (2.6). If so, the partition name is saved in the temporary list. After traversing the partition name list, if the temporary list is not empty, the text line content is copied and the partition name stored in the text line is modified to the element that exists in the temporary list. The modified text line content is then written into the power flow data file for the subnet network structure recovery stage and load recovery stage analysis in step (3.1). Then, the next line is read.

[0215] When the text line number is stored in the hash table corresponding to the owner name when the power generation / load percentage is modified by the owner in step (1.4.3), check the hash table corresponding to the owner name and the node number list in step (1.1.3) according to the owner name. If the corresponding node number list is not empty, write the text line to the file in step (3.1). For the set of owner names of each node in the black start subnet stored in step (2.6), check whether the owner name is in the set. If it is, write the text line to the power flow data file for the subnet network structure recovery stage and load recovery stage analysis in step (3.1) respectively. Then read the next line.

[0216] When the text line number is stored in the hash table corresponding to the generation / load percentage as modified by the specified owner in step (1.4.3), each owner name in the owner name list is traversed. Based on the owner name, the hash table corresponding to the owner name and node number list stored in step (1.1.3) is checked. If the corresponding node number list is not empty, the owner name is saved in a temporary list. After traversing the owner name list, if the temporary list is not empty, the text line content is copied, and the owner name stored in the text line is modified to an element existing in the temporary list. Then, the modified text line content is written back to step (1.4.3). Step (3.1) is used to calculate the power flow data file of the external network equivalent parameters; a temporary list is created for each black start subnet, and the owner name in the owner name list is queried in turn to see if it is in the set of owner names of the nodes in the subnet stored in step (2.6). If so, the owner name is saved in the temporary list. After traversing the owner name list, if the temporary list is not empty, the text line content is copied and the owner name stored in the text line is modified to the element existing in the temporary list. The modified text line content is then written into the power flow data file for the subnet network structure recovery stage and load recovery stage analysis in step (3.1); then the next line is read.

[0217] If the text line does not fall into any of the above four categories, proceed to step (3.3).

[0218] (3.5) For the file in step (3.1), write the control statements for the specified power flow calculation process and the specified power flow termination line by line.

[0219] (4) Generate stable simulation data files for calculating the equivalent parameters of the external network, and generate stable simulation data files for each black start subnet of the target power grid that are suitable for the analysis of the grid restoration stage and the analysis of the load restoration stage.

[0220] Generate stability simulation data files for calculating equivalent parameters of the external network, and generate stability simulation data files suitable for network restoration phase analysis and load restoration phase analysis for each black-start subnetwork of the target power grid. The specific steps include:

[0221] (4.1) Read the stable data file that describes the typical operating mode line by line. The file stores the stable data corresponding to the power flow data file in step (1.1). Check if it contains the text line that stores the data card specified by the stable parameter file. If it does, merge the content of the stable parameter file given in the text line with the content of the stable data file to create a new text file, and then read the new file line by line. If it does not contain the text line that stores the data card specified by the stable parameter file, then read the other text lines in the stable data file line by line.

[0222] (4.2) Create a new stable data file for calculating the equivalent parameters of the external network; create a new stable data file for each black-start subnet of the target power grid suitable for analyzing the grid recovery phase; create a new stable data file for each black-start subnet of the target power grid suitable for analyzing the load recovery phase.

[0223] (4.3) For each text line read in step (4.1), process it as follows:

[0224] When the text line stores the calculation control CASE card, modify the power flow mode name stored in the text line to the power flow mode name given in the power flow start control statement in the corresponding file of step (3.1), and then write it into the stable data file used to calculate the equivalent parameters of the external network in step (4.2); for each black start subnet of the target power grid, modify the power flow mode name stored in the text line to the power flow mode name given in the power flow start control statement in the corresponding file of step (3.1), and then write it into the stable data file corresponding to step (4.2);

[0225] When the text line storage content does not contain node feature identifiers, the text line content is directly written into the stable data file used in step (4.2) to calculate the equivalent parameters of the external network; for each black start subnet of the target power grid, the text line content is directly written into the corresponding stable data file in step (4.2); then move on to the next line to read;

[0226] When the text line contains node feature identifiers, the corresponding node number is obtained from the hash table storing the correspondence between node feature identifiers and node numbers in step (1.1.1). Then, combined with the hash table storing the relationship between node numbers and new node numbers in step (2.1.3), the graph describing the external network's communication connectivity in step (2.7) is searched to see if the node feature identifier has a corresponding vertex. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which node parameters need to be modified in step (2.8), or if there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which node parameters need to be modified in step (2.8), but... If the text line does not store DC control system model parameters, then the text line content is written into the stable data file used in step (4.2) to calculate the equivalent parameters of the external network. For each black-start subnet of the target power grid, in the connected subgraph corresponding to the black-start subnet during the load recovery phase in step (2.7), check if there is a corresponding vertex for the node feature identifier. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers whose node parameters need to be modified in step (2.6), or if there is a corresponding vertex and the corresponding node number is in the set of node numbers whose node parameters need to be modified in step (2.6), but the text line does not store DC control system model parameters. If the text line contains stable parameters of AC branch-type components, then the content of the text line is written into the stability data file for the load recovery phase analysis in step (4.2). For each black-start subnet of the target power grid, in the connected subgraph corresponding to the black-start subnet in the grid recovery phase in step (2.7), if the text line stores the stability parameters of the AC branch-type components, then the branch feature identifier is obtained from the text line, and a corresponding edge is searched in the connected subgraph. If there is one, the content of the text line is written into the stability data file for the grid recovery phase analysis in step (4.2). If not, the content of the text line is copied, a comment character is added to the beginning of the text line, and then it is written into step (4.2). In the stable data file for the analysis of the subnet structure restoration stage, if the text line does not store the stable parameters of the AC branch type element, check if the node feature identifier stored in the text line has a corresponding vertex in the connected subgraph. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which the node parameters need to be modified in step (2.6), or if there is a corresponding vertex and the corresponding node number is in the set of node numbers for which the node parameters need to be modified in step (2.6), but the text line does not store the DC control system model parameters, then write the text line content into the stable data file for the analysis of the subnet structure restoration stage in step (4.2).

[0227] (5) Calculate the equivalent parameters of the external network and correct the power flow and stability simulation data files corresponding to each black start subnet.

[0228] The calculation of external network equivalent parameters and the correction of power flow and stability simulation data files corresponding to each black-start subnet specifically include the following steps:

[0229] (5.1) Using the short-circuit current calculation program provided by PSD-BPA, based on the power flow data file used in step (3.1) to calculate the equivalent parameters of the external network and the stability data file used in step (4.2) to calculate the equivalent parameters of the external network, the positive sequence and zero sequence equivalent impedances of the inter-provincial AC tie lines of each sub-network of the target power grid at the corresponding nodes on the external network side are obtained.

[0230] (5.2) For each black start subnet of the target power grid, in the power flow data file of the analysis network restoration stage, write a text line storing equivalent AC node parameters, set the node type to balanced node, and write a text line storing equivalent AC line parameters. The equivalent AC line connects the equivalent AC node and the node of the inter-provincial tie line that started the subnet on the external network side. The line impedance parameter is the positive sequence equivalent impedance parameter obtained in step (5.1). The same method is used in the power flow data file of the analysis load restoration stage.

[0231] (5.3) For each black-start subnet of the target power grid, in the stability data file of the analysis network restoration stage, write a text line storing the parameters of the infinite bus model. This text line corresponds to the text line storing the equivalent AC node parameters in step (5.2). That is, the equivalent AC node is regarded as an infinite bus. Then write a text line storing the equivalent AC line parameters. This text line corresponds to the text line storing the equivalent AC line parameters in step (5.2). The line impedance parameters are the zero-sequence equivalent impedance parameters obtained in step (5.1). The same method is used in the stability data file of the analysis load restoration stage.

[0232] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A modeling method for a grid black start scheme based on PSD-BPA and oriented towards off-grid power source startup, characterized in that, include: Step 1: Establish a data structure for storing various types of network data; read the power flow data file in PSD-BPA format that describes typical operating modes, and process the text lines according to the data type identified by the text lines; process each text line storing network data; establish a data structure for storing modified data; process each text line storing modified data. Step 2: Perform topology analysis on the power grid; Step 3: Generate power flow simulation data files for calculating equivalent parameters of the external network, and generate power flow simulation data files suitable for network restoration stage analysis and load restoration stage analysis for each black start subnet of the target power grid; Step 4: Generate stability simulation data files for calculating equivalent parameters of the external network, and generate stability simulation data files suitable for network restoration phase analysis and load restoration phase analysis for each black-start subnet of the target power grid; Step 5: Calculate the equivalent parameters of the external network and correct the power flow and stability simulation data files corresponding to each black-start subnet.

2. The method according to claim 1, characterized in that, The establishment of a data structure for storing various types of network data includes: Establish a hash table to store the correspondence between node feature identifiers and node numbers. The key of the hash table is the node feature identifier, and the value of the hash table is the number corresponding to the node. Create a hash table to store the correspondence between node numbers and text line information. The key of the hash table is the node number, and the value of the hash table is a list. The elements of the list are tuples consisting of the data type of the text line identifier, the data modification identifier in the text line, and the corresponding line number of the text line in its file. Create a hash table to store the mapping between node numbers and partition names. The key of the hash table is the node number, and the value of the hash table is the partition name. Create a hash table to store the correspondence between partition names and node numbers. The key of the hash table is the partition name, and the value of the hash table is a list of node numbers as elements. Create a hash table to store the correspondence between node numbers and owner names. The key of the hash table is the node number, and the value of the hash table is the owner name. Create a hash table to store the correspondence between owner names and node numbers. The key of the hash table is the owner name, and the value of the hash table is the node number. Establish a hash table to store the correspondence between AC line feature identifiers and text line information. The text line stores AC line parameters. The key of the hash table is the AC line feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is a tuple consisting of the line segment number, the small switch branch identifier, the data modification identifier in the text line, and the corresponding line number of the text line in its file. Establish a hash table to store the correspondence between AC line high-resistance feature identifiers and text line numbers. The text lines store AC line high-resistance parameters. The key of the hash table is the AC line high-resistance feature identifier, which is a tuple consisting of the node numbers at both ends and the parallel circuit identifier. The value of the hash table is a list, and the list element is a tuple. The tuple consists of the data modification identifier in the text line and the corresponding line number of the text line in its file. Establish a hash table to store the correspondence between quickly adjustable line complement feature identifiers and text line information. The text line stores the quickly adjustable line complement parameters. The key of the hash table is the line complement feature identifier, and the value of the hash table is a list. The list element is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file. Create a hash table to store the correspondence between transformer / phase shifter feature identifiers and text line information. The text lines store transformer / phase shifter parameters. The key of the hash table is the transformer / phase shifter feature identifier, and the value of the hash table is a list. The list element is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file. Create a hash table to store the correspondence between the characteristic identifiers of the control parameters of the on-load voltage regulating transformer / phase shifter and the text line information. The text line stores the control parameters of the on-load voltage regulating transformer / phase shifter. The key of the hash table is the characteristic identifier of the control parameter of the on-load voltage regulating transformer / phase shifter, and the value of the hash table is a list. The list element is a tuple consisting of the data modification identifier in the text line and the corresponding line number of the text line in its file. Create a hash table to store the correspondence between the feature identifiers of the modular UPFC serial terminals and the line numbers of the text lines. The key is the feature identifier of the modular UPFC serial terminal, which is a tuple consisting of the node numbers at both ends and the parallel loop identifier. The value is a tuple consisting of the line numbers of the text lines storing the parameters and supplementary data of the modular UPFC serial terminals in their respective files. Establish a hash table to store the correspondence between DC line feature identifiers and text line information. The text lines store DC line parameters. The key of the hash table is the DC line feature identifier, which is a tuple consisting of the node numbers at both ends. The value of the hash table is a list, and the elements of the list are tuples consisting of the data modification identifier in the text line and the corresponding line number of the text line in its data file. Create a hash table to store the correspondence between LCC DC control parameter feature identifiers and text line numbers. The key is the LCC DC control parameter feature identifier, which is a tuple consisting of the rectifier low-side converter node number, rectifier high-side converter node number, inverter low-side converter node number, and inverter high-side converter node number. The value is the corresponding line number of the text line storing the LCC DC control parameter in its respective file.

3. The method according to claim 1, characterized in that, The processing of the text lines includes: Extract text lines from the data file and save them to the system's baseline capacity; Retrieve network data, iterate through all text lines storing network data, and process each text line storing network data; Check if the modified data exists. If it does, retrieve the modified data and iterate through all the text lines that store the modified data, processing each text line that stores the modified data.

4. The method according to claim 3, characterized in that, The processing of each text line of stored network data includes: When the text line stores one of the following data types: AC node parameters, AC node supplementary data, DC node parameters, DC node supplementary data, switchable reactor / capacitor bank parameters, or modular UPFC parallel terminal parameters, the hash table storing the correspondence between node feature identifiers and node numbers is queried or updated based on the node feature identifiers in the text line; the hash table storing the correspondence between node numbers and text line information is also updated. When the text line stores AC node parameters or DC node parameters, the partition name is obtained from the text line, and the hash table used to store the correspondence between node numbers and partition names and the hash table used to store the correspondence between partition names and node number lists are updated; the owner name is also obtained from the text line, and the hash table used to store the correspondence between node numbers and owner names and the hash table used to store the correspondence between owner names and node number lists are updated. When the text line stores various AC line parameters, the AC line types include symmetrical lines and asymmetrical lines. The hash table storing the correspondence between node feature identifiers and node numbers is queried or updated based on the feature identifiers of the two ends of the text line. If the text line stores symmetrical AC line parameters, the AC line corresponding to the text line is determined as a small switch branch based on the per-unit reactance value in the text line. The hash table storing the correspondence between AC line feature identifiers and text line information is then updated.

5. The method according to claim 3, characterized in that, The processing of each line of text stored in the network also includes: When the text line stores AC line high-resistance parameters, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between AC line high-resistance feature identifiers and text line numbers. When the text line stores line complement parameters that can be adjusted quickly, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between line complement feature identifiers that can be adjusted quickly and text line information. When the text line stores transformer / phase shifter parameters, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between transformer / phase shifter feature identifiers and text line information. When the text line stores control parameters of a load-regulating transformer / phase shifter, the hash table that stores the correspondence between node feature identifiers and node numbers is queried or updated based on the feature identifiers of the nodes at both ends of the text line; the hash table that stores the correspondence between the feature identifiers of the load-regulating transformer / phase shifter control parameters and the text line information is updated.

6. The method according to claim 3, characterized in that, The processing of each line of text stored in the network also includes: When the text line stores modular UPFC serial terminal parameters or modular UPFC serial terminal supplementary data, query or update the hash table that stores the correspondence between node feature identifiers and node numbers based on the feature identifiers of the nodes at both ends of the text line; update the hash table that stores the correspondence between modular UPFC serial terminal feature identifiers and text line numbers. When the text line stores various DC line parameters, the DC line types include two-end DC lines, multi-end DC lines, flexible DC lines, and LCC DC lines. Based on the feature identifiers of the two-end nodes in the text line, the hash table storing the correspondence between node feature identifiers and node numbers is queried or updated; the hash table storing the correspondence between DC line parameter feature identifiers and text line numbers is updated. When the text line stores LCC DC control parameters, based on the feature identifiers of the rectifier low-side converter node, rectifier high-side converter node, inverter low-side converter node, and inverter high-side converter node in the text line, query or update the hash table that stores the correspondence between node feature identifiers and node numbers; update the hash table that stores the correspondence between LCC DC control parameter feature identifiers and text line numbers. When a text line stores region control data, the text line is ignored.

7. The method according to claim 3, characterized in that, The processing of each text line storing modified data includes: When the text line stores new AC node parameters, supplementary AC node data, DC node parameters, supplementary DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between node feature identifiers and node numbers is queried or updated based on the node feature identifiers in the text line; the hash table storing the correspondence between node numbers and text line information is updated; when the text line stores new AC node parameters or DC node parameters, the list of deleted node numbers or the list of new node numbers stored in the data structure established for storing modified data is updated based on the node number. When the text line stores the parameters of the newly added AC node or DC node, the hash table that stores the correspondence between the node number and the partition name, as well as the hash table that stores the correspondence between the partition name and the node number list, are also updated according to the partition name in the text line. When the text line stores parameters for newly added AC or DC nodes, the hash table storing the correspondence between node numbers and owner names, as well as the hash table storing the correspondence between the list of owner names and node numbers, are also updated based on the owner name in the text line.

8. The method according to claim 3, characterized in that, The processing of each text line storing modified data also includes: When the text line stores the content of deleting AC node parameters, supplementing AC node data, DC node parameters, supplementing DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between the node number and the text line information is updated according to the node feature identifier in the text line; when the text line stores the content of deleting AC node parameters or DC node parameters, the list storing the deleted node numbers or the list storing the added node numbers in the data structure established for storing modified data is updated according to the node number. When the content stored in the text line is the restoration of deleted AC node parameters, or supplementary AC node data, or DC node parameters, or supplementary DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between the node number and the text line information is updated according to the node feature identifier in the text line; when the content stored in the text line is the restoration of deleted AC node parameters or DC node parameters, the list of deleted node numbers or the list of added node numbers in the data structure established for storing modified data is updated according to the node number. When the text line stores information about correcting AC node parameters, supplementing AC node data, DC node parameters, supplementing DC node data, or switchable reactance / capacitor bank parameters, the hash table storing the correspondence between node numbers and text line information is updated based on the node feature identifier in the text line. When the text line stores information about modifying AC node parameters or DC node parameters, the hash table storing the correspondence between node numbers and partition names, the hash table storing the correspondence between partition names and node number lists, the hash table storing the correspondence between node numbers and owner names, and the hash table storing the correspondence between owner names and node number lists are updated based on the partition name and owner name in the text line, respectively.

9. The method according to claim 3, characterized in that, The processing of each text line storing modified data also includes: When the text line stores data of one of the following types: AC line high-resistance parameters, quickly adjustable line series compensation parameters, transformer / phase shifter parameters, on-load voltage regulating transformer / phase shifter control parameters, or DC line parameters, the modification includes adding data, deleting data, correcting data, and restoring deleted data, and updating the hash table that stores the correspondence between branch feature identifiers and text line information; when the text line stores data of adding or correcting AC line parameters, it is handled in a similar manner; when the text line stores data of deleting or restoring deleted AC line parameters, and the segment number in the text line is not zero and not blank, and the parallel circuit identifier is not "*" and not blank, it is also handled in a similar manner. When the text line stores information about deleting or restoring deleted AC line parameters, if the parallel circuit identifier in the text line is "*" or blank, it indicates that all parallel AC lines have been deleted or restored. The hash table corresponding to the storage node feature identifier and text line information is updated according to the hash table of the correspondence between the text line and the storage node feature identifier and node number. If the segment number in the text line is zero or blank, it indicates that all AC lines composed of connected segments have been deleted or restored. The hash table corresponding to the storage node feature identifier and text line information is updated according to the hash table of the correspondence between the text line and the storage node feature identifier and node number.

10. The method according to claim 3, characterized in that, The processing of each text line storing modified data also includes: When the content stored in the text line is the modification of the generation / load percentage by partition, the line number of the text line in its file is used as the key, the partition name is retrieved from the text line and used as the value, and the key-value pair is added to the hash table that establishes the data structure for storing the modified data and stores the correspondence between the text line number and the partition name when the generation / load percentage is modified by partition; when the content stored in the text line is the modification of the generation / load percentage by a specified partition, the line number of the text line in its file is used as the key, all partition names are retrieved from the text line and a list constructed from all partition names is used as the value, and the key-value pair is added to the hash table that establishes the data structure for storing the modified data and stores the correspondence between the text line number and the specified partition name when the generation / load percentage is modified by a specified partition. When the content stored in the text line is the modification of the power generation / load percentage by owner, the line number of the text line in its file is used as the key, the owner name is retrieved from the text line and used as the value, and the key-value pair is added to the hash table that stores the correspondence between the text line number and the owner name when the power generation / load percentage is modified by owner in the data structure used to store the modified data. When the content stored in the text line is the modification of the power generation / load percentage by a specific owner, the line number of the text line in its file is used as the key, all owner names are retrieved from the text line and the list constructed from the owner names is used as the value, and the key-value pair is added to the hash table that stores the correspondence between the text line number and the specified owner name when the power generation / load percentage is modified by a specified owner in the data structure used to store the modified data.

11. The method according to claim 1, characterized in that, The establishment of the data structure for storing modified data includes: Step 11: For node parameters, create a list to store the IDs of newly added nodes and a list to store the IDs of deleted nodes. The elements in the lists are node IDs. Step 12: Create a hash table to store the mapping between line numbers of text lines and partition names when the power generation / load percentage is modified by partition. The key is the line number of the text line in its file, and the value is the partition name. Create another hash table to store the mapping between line numbers of text lines and a list of specified partition names when the power generation / load percentage is modified by a specified partition. The key is the line number of the text line in its file, and the value is a list of partition names. Step 13: Create a hash table to store the mapping between line numbers of text lines and owner names when the power generation / load percentage is modified by the owner. The key is the line number of the text line in its file, and the value is the owner name.

12. The method according to claim 1, characterized in that, Step 2 includes: Step 21: Create a hash table to store the relationship between node numbers and new node numbers, with node numbers as keys and new node numbers as values; create a hash table to store the relationship between new node numbers and lists of node numbers, with new node numbers as keys and lists of node numbers as values. Step 22: Traverse the hash table storing the correspondence between AC line feature identifiers and text line information, and obtain the connected subgraphs describing the AC small switch branches through topological analysis; for each connected subgraph, if there is more than one vertex in the connected subgraph, treat all nodes corresponding to the connected subgraph as one node, create a new number for all nodes corresponding to the connected subgraph that is different from all node numbers, and update the hash table in step 21 with the node number and the new node number; Step 23: Create a set of text line numbers that are independent of the external network equivalent simulation data. The text lines are stored in the file where the network data was stored in Step 1, and the data stored in the text lines must be set to invalid when constructing the external network equivalent simulation data. Step 24: For each black-start subnet of the target power grid, establish a set of text line numbers for simulation analysis during the grid restoration phase. In the network data file of Step 1, the branches and nodes represented by the text lines belong to each black-start subnet in terms of electrical topology, and the branch and node data do not need to be modified. For each black-start subnet of the target power grid, establish a set of text line numbers for simulation analysis during the load restoration phase. In the network data file of Step 1, the branches and nodes represented by the text lines belong to each black-start subnet in terms of electrical topology, and the branch and node data do not need to be modified. Step 25: For each black start subnet of the target power grid, establish a set of node numbers whose node parameters need to be modified when constructing the simulation data of the black start subnet, a set of text line information corresponding to the nodes that need to be modified, a set storing the partition name to which the nodes in the black start subnet belong, and a set storing the owner name to which the nodes in the black start subnet belong. The text line information is a tuple composed of the text line number and the data type of the text line identifier. Step 26: Traverse the hash table storing the characteristic identifiers and text line information of a certain type of AC series branch. The types of AC branches include AC lines, transformers / phase shifters, UPFC series terminals, and line series compensation that can be quickly adjusted. Combine the topology information required to divide the black start subnet in the black start scheme and the hash table in Step 21, perform AC topology analysis on the network data and the power grid represented by the modified data to obtain the AC connectivity subgraph describing the external network and the connectivity subgraph corresponding to each black start subnet of the target power grid in the load recovery stage and the grid recovery stage, and update the data structure in Steps 23, 24 and 25. Step 27: Establish a set of node numbers whose node parameters need to be modified when constructing external network equivalent simulation data, and a set of text line information corresponding to the nodes that need to be modified. The text line information is a tuple composed of text line number and the data type of the text line identifier. Step 28: Traverse the hash table storing DC line feature identifiers and text line information, perform DC topology analysis on the network data and the power grid represented by the modified data, update the connected subgraphs of the external network and each black start subnet described in Step 27, and update the data structures in Steps 23, 24 and 27.

13. The method according to claim 1, characterized in that, Step 3 includes: Step 31: Create a new power flow data file for calculating the equivalent parameters of the external network; create a new power flow data file for each black-start subnet of the target power grid, suitable for analyzing the network restoration phase; create a new power flow data file for each black-start subnet of the target power grid, suitable for analyzing the load restoration phase. Step 32: For each file in Step 31, write the specified power flow start, set the system baseline capacity, and specify the power flow result output control statement line by line. The system baseline capacity is taken from the power flow data file in PSD-BPA format that describes the typical operation mode, and the baseline capacity is saved in the processing of the text line according to the data type identified by the text line. Step 33: Read the power flow data file in PSD-BPA format that describes the typical operating mode line by line, and process the network data corresponding to the text line according to the data type identified by the text line; Step 34: Write control statements line by line to specify the data saving location. The default data saving location is the new file in Step 31. Then, read the power flow data file in PSD-BPA format that describes the typical operation mode line by line, and process the modified data in the text line according to the data type identified by the text line. Step 35: For the file in Step 31, write the control statements for the specified power flow calculation process and the specified power flow termination line by line.

14. The method according to claim 13, characterized in that, The processing of the network data corresponding to the text line includes: When the text line number is modified in the external network equivalent simulation data, if the data type of the text line identifier is a node parameter, the text line content is modified to the default value of the AC node parameter, and then the text line content is written into the power flow data file used in step 31 to calculate the external network equivalent parameters, and then the next line is read. When the text line number is not in the set of text line numbers that are not related to the storage and external network equivalent simulation data, the text line content is written to the power flow data file used in step 31 to calculate the external network equivalent parameters, and then the next line is read. When the line number of a text line matches the set of line numbers for load recovery phase analysis corresponding to a certain black-start subnet, the text line content is written to the power flow data file for load recovery phase analysis of that subnet in step 31. If the text line is not in the set of line numbers for network structure recovery phase analysis of that subnet, the text line content is copied, a comment character is added to the beginning of the text line, and then it is written to the power flow data file for network structure recovery phase analysis of that subnet in step 31. If the text line is in the set of line numbers for network structure recovery phase analysis of that subnet, the text line content is written to the power flow data file for network structure recovery phase analysis of that subnet in step 31. Then proceed to the next line to read. When the text line number needs to be modified in the text line information set corresponding to a node in the simulation data of a certain black start subnet, if the data type of the text line identifier is a node parameter, modify the text line content to the default value of the AC node parameter, and then write the text line content into the power flow data file for the subnet structure recovery stage and load recovery system analysis in step 31, and then move on to the next line to read.

15. The method according to claim 13, characterized in that, The processing of modified data in the text line includes: When the text line number is in the hash table corresponding to the text line number and partition name when the storage generation / load percentage is modified by partition in step 2 of establishing the data structure for storing modified data, check the hash table corresponding to the storage partition name and node number list according to the partition name. If the corresponding node number list is not empty, write the text line into the power flow data file used in step 31 to calculate the external network equivalent parameters; for each set of partition names to which the nodes in the storage black start subnet belong, check whether the partition name is in the set. If it is, write the text line into the power flow data file for the analysis of the subnet network structure recovery stage and load recovery stage in step 31 respectively; then move on to the next line to read; When the text line number is in the hash table corresponding to the text line number and the partition name list when the power generation / load percentage is modified by specified partition in step 2 of establishing the data structure for storing modified data, the hash table corresponding to the partition name and the node number list is traversed. If the corresponding node number list is not empty, the partition name is saved in a temporary list. After traversing the partition name list, if the temporary list is not empty, the text line content is copied and the partition name stored in the text line is modified to the element existing in the temporary list. Then the modified text line is... The content is written into the power flow data file used in step 31 to calculate the equivalent parameters of the external network; a temporary list is created for each black-start subnet, and the partition names in the partition name list are queried in turn to see if they are in the set of partition names of the nodes in the storage subnet. If so, the partition names are saved in the temporary list. After traversing the partition name list, if the temporary list is not empty, the text line content is copied and the partition names stored in the text line are modified to the elements existing in the temporary list. The modified text line content is then written into the power flow data file used in step 31 for the subnet network structure recovery phase and load recovery phase analysis respectively; then the next line is read.

16. The method according to claim 13, characterized in that, The processing of modified data in the text line further includes: when the text line number is in the hash table of the correspondence between the text line number and the owner name when the storage power generation / load percentage is modified by the owner in step 3 of establishing the data structure for storing modified data, check the hash table of the correspondence between the storage owner name and the node number list according to the owner name. If the corresponding node number list is not an empty list, write the text line to the file in step 31; for the set of owner names of each node in the storage black start subnet in step 25, query whether the owner name is in the set. If it is, write the text line to the power flow data file for the subnet network structure recovery stage and load recovery stage analysis in step 31 respectively; then move on to the next line to read. When the text line number is in the hash table corresponding to the text line number and the list of owner names when the power generation / load percentage is modified according to the specified owner in step 3 of establishing the data structure for storing modified data, the process iterates through each owner name in the owner name list. It then checks the hash table corresponding to the list of owner names and node numbers. If the corresponding node number list is not empty, the owner name is saved in a temporary list. After iterating through the owner name list, if the temporary list is not empty, the text line content is copied, and the owner name stored in the text line is modified to match the element existing in the temporary list. Finally, the modified text line is... The text line content is written into the power flow data file used in step 31 to calculate the equivalent parameters of the external network; a temporary list is created for each black-start subnet, and the owner name in the owner name list is checked in turn to see if it is in the set of owner names of the nodes in the storage subnet in step 25. If so, the owner name is saved in the temporary list. After traversing the owner name list, if the temporary list is not empty, the text line content is copied and the owner name stored in the text line is modified to the element existing in the temporary list. The modified text line content is then written into the power flow data file for the subnet network structure recovery stage and load recovery stage analysis in step 31 respectively; then the next line is read. If the text line does not fall into any of the above four categories, proceed to step 33.

17. The method according to claim 1, characterized in that, Step 4 includes: Step 41: Read the stable data file depicting the typical operating mode line by line. The file stores the stable data corresponding to the power flow data file in the data structure used to store various types of network data. Check if it contains a text line that stores the data card specified by the stable parameter file. If it does, merge the content of the stable parameter file given in the text line with the content of the stable data file to create a new text file, and then read the new file line by line. If it does not contain a text line that stores the data card specified by the stable parameter file, then read the other text lines in the stable data file line by line. Step 42: Create a new stable data file for calculating the equivalent parameters of the external network; create a new stable data file for each black-start subnet of the target power grid, suitable for analyzing the grid recovery phase; create a new stable data file for each black-start subnet of the target power grid, suitable for analyzing the load recovery phase. Step 43: Process each line of text read in step 41.

18. The method according to claim 17, characterized in that, Step 43 includes: When the text line stores the calculation control CASE card, modify the power flow mode name stored in the text line to the power flow mode name given in the power flow start control statement in the corresponding file in step 31, and then write it into the stable data file used to calculate the equivalent parameters of the external network in step 42; for each black start subnet of the target power grid, modify the power flow mode name stored in the text line to the power flow mode name given in the power flow start control statement in the corresponding file, and then write it into the stable data file corresponding to step 42. When the text line storage content does not contain node feature identifiers, the text line content is directly written to the stable data file used in step 42 to calculate the equivalent parameters of the external network; for each black start subnet of the target power grid, the text line content is directly written to the corresponding stable data file in step 42; then proceed to the next line to read.

19. The method according to claim 17, characterized in that, Step 43 further includes: When the text line stores node feature identifiers, the corresponding node number is retrieved from the hash table that stores the correspondence between node feature identifiers and node numbers. Then, combined with the hash table that stores the relationship between node numbers and new node numbers, the system searches in the AC connectivity subgraph describing the external network to see if there is a corresponding vertex for the node feature identifier. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which the node parameters need to be modified, or if there is a corresponding vertex and the corresponding node number is in the set of node numbers for which the node parameters need to be modified, but the text line does not store DC control system model parameters, then the text line content is written into the stable data file used in step 42 to calculate the equivalent parameters of the external network.

20. The method according to claim 17, characterized in that, Step 43 further includes: For each black-start subnet of the target power grid, in the connected subgraph corresponding to the black-start subnet during the load recovery phase, check whether there is a corresponding vertex for the node feature identifier. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers for which the node parameters need to be modified, or if there is a corresponding vertex and the corresponding node number is in the set of node numbers for which the node parameters need to be modified, but the text line does not store DC control system model parameters, then write the text line content into the stable data file for the load recovery phase analysis in step 42. For each black-start subnet of the target power grid, in the connected subgraph corresponding to the black-start subnet during the grid restoration phase, if the text line stores the stability parameters of AC branch type components, then the branch feature identifier is obtained from the text line, and the corresponding edge is checked in the connected subgraph. If it exists, the text line content is written into the stability data file for grid restoration phase analysis in step 42. If it does not exist, the text line content is copied, a comment character is added to the beginning of the text line, and then it is written into the stability data file for grid restoration phase analysis of that subnet in step 42. When the text line does not store the stability parameters of AC branch type components, the node feature identifier stored in the text line is checked to see if there is a corresponding vertex in the connected subgraph. If there is a corresponding vertex and the corresponding node number is not in the set of node numbers whose node parameters need to be modified, or if there is a corresponding vertex and the corresponding node number is in the set of node numbers whose node parameters need to be modified, but the text line does not store DC control system model parameters, then the text line content is written into the stability data file for grid restoration phase analysis in step 42.

21. The method according to claim 1, characterized in that, Step 5 includes: Step 51: Using the short-circuit current calculation program provided by PSD-BPA, based on the power flow data file used in Step 31 to calculate the equivalent parameters of the external network and the stability data file used in Step 42 to calculate the equivalent parameters of the external network, obtain the positive sequence and zero sequence equivalent impedances of the inter-provincial AC tie lines of each sub-network of the target power grid at the corresponding nodes on the external network side. Step 52: For each black-start subnet of the target power grid, in the power flow data file during the analysis of the grid restoration phase, write a text line storing equivalent AC node parameters, set the node type to balanced node, and write a text line storing equivalent AC line parameters. The equivalent AC line connects the equivalent AC node and the node on the external network side of the inter-provincial tie line that started the subnet. The line impedance parameter is the positive-sequence equivalent impedance parameter obtained in Step 51. The same process is applied in the power flow data file during the analysis of the load restoration phase. Step 53: For each black-start subnet of the target power grid, in the stability data file of the analysis network restoration phase, write a text line storing the parameters of the infinite bus model. This text line corresponds to the text line storing the equivalent AC node parameters in Step 52. That is, the equivalent AC node is regarded as an infinite bus. Then write a text line storing the equivalent AC line parameters. This text line corresponds to the text line storing the equivalent AC line parameters in Step 52. The line impedance parameters are the zero-sequence equivalent impedance parameters obtained in Step 51. The same process is used in the stability data file of the analysis load restoration phase.

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