Power supply capability evaluation method, device and equipment of low-voltage distribution network and medium

Abstract

The embodiment of the invention relates to the technical field of computers, and provides a power supply capability evaluation method, device and equipment for a low-voltage distribution network and a medium, and the method comprises the steps: obtaining a target directed graph model when a fault of a target low-voltage distribution network is detected; based on the load data of each node in the target low-voltage distribution network and the target directed graph model, obtaining a target load node set used for preferentially recovering power supply in the non-fault area; according to the position and the parameter of the distributed device in the target directed graph model and the target load node set, performing path search from the node where the distributed device is located in the target directed graph model to obtain a target power supply recovery path; and performing power supply capability evaluation on the target low-voltage distribution network based on the recovered operation state of the target low-voltage distribution network after executing the target power supply recovery path to obtain a power supply capability evaluation value of the target low-voltage distribution network. Path search is carried out through the directed graph model to realize power supply capability evaluation, and power supply reliability and recovery efficiency are improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of computer technology, and in particular to a method for evaluating the power supply capacity of a low-voltage distribution network, a device for evaluating the power supply capacity of a low-voltage distribution network, a corresponding electronic device, and a corresponding computer-readable storage medium. Background Art

[0002] In the current power supply system, the distribution network in the low-voltage area (hereinafter referred to as the low-voltage distribution network) is a key link directly facing users. Its stable operation is crucial to ensuring reliable power supply. For example, in the scenario of a new large plant, it is predicted that the load of the distribution transformer (hereinafter referred to as the distribution transformer) near the new large plant will increase significantly. At this time, there is a need to build a new distribution transformer for load cutover. However, for the low-voltage distribution network with complex structure, numerous equipment and wide distribution, regional faults are prone to occur in the process of new distribution transformer operation. When a distribution network fails, quickly restoring power supply capacity is the key to ensuring normal power supply for users and reducing economic losses and social impacts.

[0003] In the related technologies for quickly restoring power supply capacity after a distribution network fault, power supply capacity evaluation can be performed based on traditional topology analysis methods or simple heuristic algorithms. Among them, the power supply capacity evaluation scheme based on the topology structure is usually manifested as modeling and analyzing the topology structure of the distribution network to determine possible recovery paths after the fault; the power supply capacity evaluation scheme based on a simple heuristic algorithm is usually manifested as providing a recovery scheme for a simple distribution network environment. However, whether it is a power supply capacity evaluation scheme based on the topology structure or a power supply capacity evaluation scheme based on a simple heuristic algorithm, due to the uncertainty of the low-voltage distribution network operating environment, it is difficult to accurately perform power supply capacity evaluation and it is difficult to effectively achieve power supply restoration effects. Summary of the invention

[0004] The embodiments of the present application provide a method, device, equipment and medium for evaluating the power supply capacity of a low-voltage distribution network, which can improve the power supply reliability and recovery efficiency of the distribution network in the low-voltage area and effectively achieve the power supply recovery effect.

[0005] In one aspect, an embodiment of the present application provides a method for evaluating power supply capacity of a low voltage distribution network, the method comprising:

[0006] When a fault is detected in the target low-voltage distribution network, a target directed graph model is obtained; the target directed graph model is a directed graph model after the nodes and edges in the fault area are removed from the initial directed graph model, and the positions and parameters of the distributed devices in the non-fault area are marked in the target directed graph model;

[0007] Based on the load data of each node in the target low-voltage distribution network and the target directed graph model, a target load node set for priority power restoration in the non-fault area is obtained;

[0008] According to the position and parameters of the distributed device in the target directed graph model and the target load node set, a path search is performed starting from the node where the distributed device in the target directed graph model is located to obtain a target power supply restoration path;

[0009] Based on the post-recovery operating status of the target low-voltage distribution network after executing the target power supply recovery path, a power supply capacity evaluation is performed on the target low-voltage distribution network to obtain a power supply capacity evaluation value of the target low-voltage distribution network; the power supply capacity evaluation value is used to indicate the ability to quickly restore power supply after a fault.

[0010] On the other hand, an embodiment of the present application further provides a device for evaluating the power supply capacity of a low-voltage distribution network, the device comprising:

[0011] A directed graph model acquisition module is used to acquire a target directed graph model when a fault is detected in the target low-voltage distribution network; the target directed graph model is a directed graph model after the nodes and edges in the fault area are removed from the initial directed graph model, and the location and parameters of the distributed devices in the non-fault area are marked in the target directed graph model;

[0012] A load node acquisition module, used to acquire a target load node set for priority power restoration in the non-fault area based on the load data of each node in the target low-voltage distribution network and the target directed graph model;

[0013] A path search module, configured to perform a path search starting from the node where the distributed device is located in the target directed graph model according to the location and parameters of the distributed device in the target directed graph model and the target load node set, to obtain a target power supply restoration path;

[0014] A power supply capacity evaluation module is used to evaluate the power supply capacity of the target low-voltage distribution network based on the post-recovery operating status of the target low-voltage distribution network after executing the target power supply recovery path, and obtain a power supply capacity evaluation value of the target low-voltage distribution network; the power supply capacity evaluation value is used to indicate the ability to quickly restore power supply after a fault.

[0015] On the other hand, an embodiment of the present application further provides an electronic device, comprising: a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein when the computer program is executed by the processor, any one of the methods for evaluating the power supply capacity of the low-voltage distribution network is implemented.

[0016] On the other hand, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, any one of the methods for evaluating the power supply capacity of a low-voltage distribution network is implemented.

[0017] On the other hand, an embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the power supply capacity evaluation method of the low-voltage distribution network described in the above aspects.

[0018] The power supply capacity evaluation method, device, equipment and storage medium of the low-voltage distribution network provided in the embodiments of the present application, when a fault is detected in the target low-voltage distribution network, by taking into account the position and parameters of the distributed equipment in the non-fault area, starting from the node where the distributed equipment is located in the target directed graph model, a path search is performed on the target load node set to obtain a target power supply recovery path for evaluating the power supply capacity of the target low-voltage distribution network that executes the power supply recovery path, which can not only ensure that the searched target power supply recovery path can adapt to the dynamic changes of the power system while reflecting the operating status of the distribution network based on the marked position and parameters, but also ensure the accuracy of the evaluation of the power supply capacity that can be quickly restored after the distribution network fault is restored, thereby achieving the accuracy and effectiveness of power supply recovery and improving the power supply reliability of the low-voltage distribution network; it can also use the target directed graph model to search only for paths with directed connections during the path search process, without the need to search all paths, thereby improving the recovery efficiency of the low-voltage distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flowchart of the steps of a method for evaluating the power supply capacity of a low-voltage distribution network provided in an embodiment of the present application;

[0020] Figure 2 It is a flowchart of the steps of another method for evaluating the power supply capacity of a low-voltage distribution network according to an embodiment of the present application;

[0021] Figure 3 It is a structural block diagram of a power supply capacity evaluation device for a low-voltage distribution network according to an embodiment of the present application;

[0022] Figure 4 is a structural block diagram of an electronic device provided in an embodiment of the present application;

[0023] Figure 5 It is a structural block diagram of a computer-readable storage medium provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0025] The reliable and stable operation of the low-voltage distribution network is conducive to ensuring the reliable supply of electricity. Therefore, when a fault occurs in a low-voltage distribution network area, there is a need to quickly restore power supply to the faulty distribution network to improve the power supply reliability and recovery efficiency of the distribution network in the low-voltage area.

[0026] In the related technologies for quickly restoring power supply capacity after a distribution network fault, as an example, a power supply capacity evaluation scheme based on a topological structure can be adopted. This scheme is usually manifested as modeling and analyzing the topological structure of the distribution network to determine possible recovery paths after the fault. However, the aforementioned scheme ignores the dynamic characteristics of the power system in actual operation, such as real-time changes in loads, access to distributed power sources, and other factors. With the widespread application of power equipment such as distributed power sources and energy storage devices in distribution networks, the complexity and uncertainty of distribution networks will be further increased, resulting in insufficient accuracy and effectiveness of recovery schemes. As another example, a power supply capacity evaluation scheme based on a simple heuristic algorithm can be adopted. This scheme is usually manifested as providing a recovery scheme for a simple distribution network environment. Although the aforementioned scheme can quickly provide a recovery scheme to a certain extent, it lacks the ability to dynamically adjust the global optimal solution, is prone to falling into local optimality, and cannot achieve the best power supply recovery effect in a complex distribution network environment.

[0027] In summary, the above-mentioned related technologies are difficult to effectively achieve power supply restoration effects due to the uncertainty of the low-voltage distribution network operating environment.

[0028] In the embodiment of the present application, when a fault is detected in the target low-voltage distribution network, a target directed graph model that takes into account the positions and parameters of distributed devices in non-fault areas is adopted. Starting from the nodes where the distributed devices are located in the target directed graph model, a path search is performed on the target load node set to obtain a target power supply recovery path for use in evaluating the power supply capacity of the target low-voltage distribution network that executes the power supply recovery path. This not only ensures that the searched target power supply recovery path can adapt to dynamic changes in the power system while reflecting the operating status of the distribution network based on the marked positions and parameters, but also ensures the accuracy of the evaluation of the ability to quickly restore power supply after the distribution network fault is restored, thereby achieving the accuracy and effectiveness of power supply recovery and improving the power supply reliability of the low-voltage distribution network. In addition, the target directed graph model can be used to search only paths with directed connections during the path search process, without the need to search all paths, thereby improving the recovery efficiency of the low-voltage distribution network. Furthermore, a depth-first search (DFS) algorithm can be used to search for multiple feasible power restoration paths, and a multi-objective decision-making evaluation can be performed on each power restoration path based on the path information of each power restoration path to select the optimal final power restoration path. This enables a global search to be performed in a complex distribution network environment, avoiding falling into local optimality, and further achieving better power restoration effects.

[0029] Reference Figure 1 , shows a flowchart of a method for evaluating the power supply capacity of a low-voltage distribution network provided in an embodiment of the present application, which may specifically include the following steps:

[0030] Step S101, when a target low-voltage distribution network fault is detected, a target directed graph model is obtained;

[0031] The power supply capacity assessment method for a low-voltage distribution network provided in the embodiment of the present application can be applied to a power supply capacity assessment system. The power supply capacity assessment system can be a tool or platform for analyzing and assessing the power supply capacity of a power system or a specific power supply area. The embodiment of the present application is not limited to this.

[0032] Optionally, the target low-voltage distribution network can be any low-voltage distribution network in the power system. The low-voltage distribution network can include multiple nodes, and each node can be deployed with multiple types of sensors, such as voltage sensors, current sensors, temperature sensors, etc.; distributed equipment can also be connected to the low-voltage distribution network, and the distributed equipment can include energy and energy storage equipment, among which distributed energy such as solar photovoltaic energy, geothermal energy, natural gas energy, etc., and energy storage equipment includes heat storage equipment, flywheel energy storage units, small compressed air energy storage equipment, etc., and the embodiments of the present application are not limited to this.

[0033] In some embodiments of the present application, when a fault occurs in a low-voltage distribution network area, there is a need to quickly restore power supply to the faulty distribution network. In order to improve the power supply reliability and recovery efficiency of the distribution network in the low-voltage area, the embodiments of the present application can be implemented by searching for paths with directed connections by adopting a directed graph model when a power supply capacity evaluation system detects a fault in the target low-voltage distribution network.

[0034] In practical applications, the detection of distribution network faults can be achieved by the power supply capacity assessment system detecting whether the distribution network has faults in real time through the electrical quantity change detection method and the fault indicator method. As an example, for the electrical quantity change detection method, the current magnitude is monitored in real time through the current transformers installed in each branch of the distribution network. When a short circuit or other fault occurs in the distribution network, the current near the fault point will increase significantly in an instant, usually far exceeding the current value during normal operation, that is, by setting a reasonable current threshold, when the current exceeds the above-set current threshold, it can be preliminarily determined that the distribution network has faults; as another example, in the fault indicator method, the fault indicator refers to the monitoring equipment installed on the distribution line, which can be divided into a short circuit fault indicator and a ground fault indicator. When a short circuit fault occurs in the line, the short circuit fault indicator determines and indicates the occurrence of the fault by detecting the sudden change, direction and other characteristics of the current.

[0035] Furthermore, when a fault is detected in the target low-voltage distribution network, the directed graph model obtained by the power supply capacity assessment system can be a target directed graph model. The target directed graph model is mainly a directed graph model after removing the nodes and edges of the fault area from the initial directed graph model, that is, a post-fault directed graph model. This is to avoid searching for power supply recovery paths through nodes in the fault area when the target directed graph model is used for subsequent path search. This can effectively achieve the power supply recovery effect by searching only for paths with directed connections through the directed graph model to improve the power supply recovery efficiency.

[0036] Among them, the initial directed graph model can be mainly constructed based on the network topology structure of the target low-voltage distribution network. The network topology structure data may include the connection relationship and line parameters of each node in the target low-voltage distribution network. Exemplarily, the power supply capacity evaluation system can construct an initial directed graph model with each node as a vertex in the graph and each line as a directed edge. Each line can be used to indicate the connection relationship between nodes. The directed edges in the constructed initial directed graph model can be bidirectional edges. The specific construction process of the initial directed graph model is not limited in the embodiments of the present application.

[0037] Optionally, the power supply capacity evaluation system can also mark the location and parameters of the distributed equipment in the initial directed graph model, wherein the distributed equipment may include a distributed power source and an energy storage device. The location marking of the distributed equipment in the directed graph model is conducive to clarifying the specific location of the node where the distributed equipment is located, as well as the surrounding nodes of the node where the distributed equipment is located; the parameter marking of the distributed equipment in the directed graph model is conducive to clarifying the performance configuration of each distributed equipment, that is, the marked location and parameters in the directed graph model can reflect the operating status of the distribution network in real time. It should be noted that the specific marking process of the location and parameters is not limited in the embodiments of the present application.

[0038] In some embodiments of the present application, when a fault in the distribution network is detected, the power supply capacity assessment system can determine the fault location information of the fault area where the fault occurs in the target low-voltage distribution network, and then can remove the nodes and edges of the fault area from the initial directed graph model based on the fault location information to obtain the target directed graph model, that is, the post-fault directed graph model.

[0039] Among them, the positions and parameters of distributed devices are marked in the initial directed graph model, and the positions and parameters of distributed devices are also marked in the target directed graph model obtained on the basis of the initial directed graph model; however, the target directed graph model is a post-fault directed graph model, and the positions and parameters of distributed devices in non-fault areas are mainly marked in the target directed graph model to avoid subsequent searches for power supply restoration paths through nodes in the fault area, and to be able to adapt to dynamic changes in the power system, ensure the accuracy of the power supply restoration path, and improve the search speed of the power supply restoration path, thereby improving the power supply restoration efficiency.

[0040] Step S102, based on the load data of each node in the target low-voltage distribution network and the target directed graph model, a target load node set for priority power restoration in the non-fault area is obtained;

[0041] When the power supply capacity assessment system detects a fault in the distribution network and quickly restores power to the faulty distribution network, after obtaining the target directed graph model, it can determine the target load node set in the non-fault area for priority power restoration, thereby performing a path search based on the target directed graph model and the target load node set.

[0042] In some embodiments of the present application, the power supply capacity assessment system can perform load assessment on nodes in non-fault areas of the distribution network based on the load data of each node in the distribution network and a post-fault directed graph model to obtain a set of target load nodes for prioritizing power supply restoration.

[0043] Exemplarily, the load data of each node may include the real-time load size, load type and load interruption cost of each node, the load type includes residential load, commercial load and industrial load, wherein residential load has a higher priority than commercial load, and commercial load has a higher priority than industrial load.

[0044] In practical applications, first, the power supply capacity evaluation system can determine the nodes in the non-fault area of ​​the distribution network based on the directed graph model after the fault and all the nodes in the distribution network, and then evaluate the load of the nodes in the non-fault area of ​​the distribution network based on the real-time load size, load type and load interruption cost of each node. It should be noted that the embodiment of the present application does not limit the specific load evaluation process.

[0045] Step S103, according to the location and parameters of the distributed device in the target directed graph model and the target load node set, a path search is performed starting from the node where the distributed device is located in the target directed graph model to obtain a target power supply restoration path;

[0046] In some embodiments of the present application, the power supply capability evaluation system may perform a path search in a post-fault directed graph model according to a target load node set based on a depth-first search algorithm to obtain a target power supply recovery path.

[0047] Specifically, according to the location and parameters of the distributed equipment in the target directed graph model, starting from the node where the distributed equipment is located in the target directed graph model, a path search can be performed on the target load node set to find a path that can be connected to the target load node in the target load node set, and the line capacity on the path must meet multiple feasible initial power supply recovery paths that meet the preset load power supply requirements, so as to obtain the initial power supply recovery path.

[0048] Furthermore, according to the path information of each initial power supply restoration path, a multi-objective decision-making evaluation can be performed on each initial power supply restoration path to obtain a target power supply restoration path, and then the optimal final power supply restoration path can be selected, so that a global search can be performed in a complex distribution network environment to avoid falling into a local optimum and achieve a better power supply restoration effect. Among them, the path information may include path length, line remaining capacity and power supply restoration time. The path length can be determined based on the number of nodes of each initial power supply restoration path, the line remaining capacity can be determined based on the path length and the rated capacity of each edge contained therein and the current transmitted power, and the power supply restoration time can be determined based on the path length, the line transmission speed and the switch operation time. The specific multi-objective decision-making evaluation process is not limited by the embodiments of the present application.

[0049] Step S104, based on the post-recovery operating state of the target low-voltage distribution network after executing the target power supply recovery path, the power supply capacity of the target low-voltage distribution network is evaluated to obtain a power supply capacity evaluation value of the target low-voltage distribution network.

[0050] In some embodiments of the present application, after selecting the optimal final power supply restoration path, the power supply capacity evaluation system can execute the finally selected target power supply restoration path to restore power to the faulty target low-voltage distribution network, obtain the operating status of the target low-voltage distribution network after power is restored, and based on the restored operating status, evaluate the power supply capacity of the target low-voltage distribution network's ability to quickly restore power after a fault.

[0051] Specifically, the power supply restoration capability index can be determined according to the operating status of the distribution network after power supply restoration, and then the power supply capability is evaluated according to the power supply restoration capability index to obtain the power supply capability evaluation value of the target low-voltage distribution network; the power supply capability evaluation value is used to indicate the ability to quickly restore power supply after a fault. It should be noted that the embodiments of the present application do not limit the specific power supply capability evaluation process.

[0052] In an embodiment of the present application, when a fault is detected in the target low-voltage distribution network, a target directed graph model that takes into account the positions and parameters of distributed devices in non-fault areas is adopted. Starting from the nodes where the distributed devices are located in the target directed graph model, a path search is performed on the target load node set to obtain a target power supply recovery path for use in evaluating the power supply capacity of the target low-voltage distribution network that executes the power supply recovery path. This not only ensures that the searched target power supply recovery path can adapt to the dynamic changes of the power system while reflecting the operating status of the distribution network based on the marked positions and parameters, but also ensures the accuracy of the evaluation of the ability to quickly restore power supply after the distribution network fault is restored, thereby achieving the accuracy and effectiveness of power supply recovery and improving the power supply reliability of the low-voltage distribution network. The target directed graph model can also be used to search only paths with directed connections during the path search process, without the need to search all paths, thereby improving the recovery efficiency of the low-voltage distribution network.

[0053] Reference Figure 2 , shows a flowchart of another method for evaluating the power supply capacity of a low-voltage distribution network provided in an embodiment of the present application, which is applied to a power supply capacity evaluation system and may specifically include the following steps:

[0054] Step S201, constructing an initial directed graph model based on the network topology of the target low-voltage distribution network;

[0055] When a fault occurs in a low-voltage distribution network area, the power supply capacity assessment system of the embodiment of the present application can obtain a power supply recovery path by using a directed graph model to search for paths with directed connections, and execute the power supply recovery path to perform power restoration, thereby meeting the demand for rapid power restoration of the faulty distribution network and improving the power supply reliability and recovery efficiency of the distribution network in the low-voltage area.

[0056] The application of directed graph models is mainly manifested in the use of post-fault directed graph models, and the post-fault directed graph model is obtained based on the processing of the initial directed graph model. The power supply capacity assessment system can first construct an initial directed graph model of the target low-voltage distribution network; further, in order to reflect the operating status of the distribution network in real time and meet the adaptability to the dynamic changes of the power system, the location and parameters of the distributed power sources and energy storage devices can be marked in the constructed initial directed graph model.

[0057] In some embodiments of the present application, the power supply capacity evaluation system can construct an initial directed graph model of the target low-voltage distribution network based on the network topology of the target low-voltage distribution network, wherein the network topology data may include the connection relationship and line parameters of each node in the target low-voltage distribution network. Exemplarily, the power supply capacity evaluation system can construct an initial directed graph model with each node as a vertex in the graph and each line as a directed edge. It should be noted that each line in the initial directed graph model can be used to indicate the connection relationship between nodes, and the directed edges in the constructed initial directed graph model can be bidirectional edges, which is not limited in the embodiments of the present application.

[0058] In practical applications, the construction process of the initial directed graph model may include the process of establishing node numbers and mapping relationships, the process of depth-first search traversal, the process of building edges and adding line parameters, and the process of marking distributed power sources and energy storage devices.

[0059] The process of establishing node numbers and mapping relationships can be expressed as the power supply capability assessment system assigning unique number information to each node in the target low-voltage distribution network, and establishing a mapping relationship between the number information of each node and the actual node information, such as name, type, etc. For example, assuming that the node set is , where m represents the number of nodes, which can be the i-th node n i Assignment number information ID i , i=1,2,...m.

[0060] Among them, the nodes in the target low-voltage distribution network may include power supply nodes. The depth-first search traversal process can be specifically manifested as taking the power supply node as the starting point and using the depth-first search algorithm to traverse the entire target low-voltage distribution network. During the traversal process, a child node set can be obtained, the child node set of each node can be recorded, and a number can be assigned to each child node based on the numbering information of the parent node, that is, the numbering information of each node.

[0061] Optionally, the power supply capability evaluation system can adopt the hierarchical numbering information method to start from the power supply node, obtain the child node set of each node according to the depth-first search, and number each child node in the child node set of each node in sequence according to the numbering information of each node, and obtain the coding information of each child node in the child node set of each node. For example, assuming that the current parent node is n c , whose child node set is , where k represents the number of child nodes in the child node set, then at the current parent node n c The numbering information of the next i-th child node can be expressed as: , where i=1,2,...k, c i is an element in the aforementioned child node set, ID c Refers to the current parent node n c The assigned number information, the assigned number information ID c Can be based on the ID information of the corresponding i-th node i Sure.

[0062] The process of building edges and adding line parameters can be expressed as traversing all node pairs, including parent nodes and their child nodes, checking whether there is a connection relationship between any two nodes, and building edges for node pairs with a connection relationship. The constructed edges can be bidirectional edges. At this time, corresponding line parameter information can also be added to the edges based on the resistance parameters and reactance parameters between any two nodes mentioned above.

[0063] Optionally, for all node pairs, including the parent node and its child nodes, the power supply capability assessment system can traverse any two nodes, and for any two nodes that have a connection relationship, construct the edge between any two nodes to obtain the edge set of the directed graph. For example, for the child nodes under a parent node, assume that the following connection relationship data exists: , where, as an example, (n i1 ,n i2 ) represents the first child node n under the i-th parent node i1 To the second child node n i2 There is a connection. At this time, for the connection relationship of the child nodes under the current parent node (n i1 ,n i2), which can be converted into a directed edge (ID i1 ,ID i2 ), as another example, (n ik-1 ,n ik ) represents the k-1th child node n under the i-th parent node ik-1 To the kth child node n ik There is a connection. For the connection relationship between the child nodes under the i-th parent node (n ik-1 ,n ik ), which can be converted into a directed edge (ID ik-1 ,ID ik ). Optionally, the directed edges obtained from the above transformation can be added to the edge set middle.

[0064] Optionally, the power supply capability evaluation system can add line parameter information to the edge between any two nodes based on the resistance parameter and reactance parameter between any two nodes. i1 ,ID i2 ) is R i1,i2 , reactance is X i1,i2 , then the edge parameter is expressed as .

[0065] The process of marking distributed power sources and energy storage devices can be expressed as marking the location of the distributed power source according to the first target node information and adding parameter tags to its nodes according to the power supply capacity, and marking the location of the energy storage device according to the second target node information and adding parameter tags to its nodes according to the rated capacity, rated charging power and rated discharging power.

[0066] Exemplarily, it is assumed that the first target node information of the distributed power source, that is, the distributed power source set is , the second target node information of the energy storage device, that is, the energy storage device set is , where p represents the number of distributed power sources and q represents the number of energy storage devices. At this time, for the i-th distributed power source and the jth energy storage device , we can find the i-th distributed power source Node ID information and the jth energy storage device Node ID information ; Then, the position can be marked based on the node number information found above, and the marking rule can be: represents a distributed power generation node, Represents the energy storage device node, completing the location marking of the distributed power source and energy storage device.

[0067] After the position marking of the distributed power source and the energy storage device is completed, the distributed power source and the energy storage device can be parameter marked. For example, assuming that the distributed power source The power capacity is , for distributed power nodes , is the distributed power node The parameters of the tag can be expressed as: ; Assuming the energy storage device The rated capacity is , the rated charging power is , the rated discharge power is , for the energy storage device node , is the energy storage device node The parameters of the tag can be expressed as: .

[0068] In some embodiments of the present application, the power supply capacity assessment system can integrate the above-mentioned node numbers, mapping relationships, edges and line parameters, and marking information of distributed power sources and energy storage devices into a complete graph model, thereby constructing an initial directed graph model; wherein the integration process can be specifically expressed as the above-mentioned process, that is, after completing the node numbering and mapping relationship establishment process, the depth-first search traversal process, the edge construction and line parameter addition process, and the distributed power sources and energy storage device marking process, it indicates that the process of constructing the initial directed graph model is completed.

[0069] It should be noted that the constructed mapping relationship can quickly locate the child nodes of the current node and assign numbers to them, and in the traversal process, the constructed mapping relationship can be used to record the child node set of each node to ensure the integrity and correctness of the traversal; and through the constructed mapping relationship, the numbers of any two nodes can also be quickly found, and it can be determined whether there is a connection relationship between any two nodes. When constructing an edge, the mapping relationship can also help convert the node number into an actual node object, so as to add line parameters such as resistance, reactance, etc. to the edge; and, the nodes where the distributed power source and energy storage device are located can also be quickly located through the constructed mapping relationship, and when marking parameters, the mapping relationship can help convert the node number into an actual node object, so as to add parameters to it, such as power capacity, rated capacity, etc. The specific application process of the constructed mapping relationship in the process of constructing the initial directed graph model is not limited by the embodiments of the present application.

[0070] In some preferred embodiments of the present application, the connectivity and rationality checks may also be performed on the constructed initial directed graph to ensure that there are no isolated nodes in the graph and that the parameters of the nodes and edges conform to actual physical laws.

[0071] For example, the connectivity check method can be specifically performed by using a depth-first search algorithm to traverse the directed graph and count the number of reachable nodes. For example, assuming that the reachable node set is V reachable , initially , you can now select any node ID s Start DFS traversal, ID s Can be the above ID i and ID ck Any item of , at this time, the reachable node can be added to the reachable node set V reachable In the case where the traversal is completed, , then it means that the graph is connected. As mentioned above, m represents the number of nodes. The rationality check can be specifically performed by checking whether the transformer capacity of the node and the rated current of the switchgear meet the requirements of the line parameters. For example, assuming that the kth node The transformer capacity is , the rated current of the kth switching device is , the maximum current of the line connected to the kth node is , the rationality judgment formula can be shown as follows:

[0072] ;

[0073] Among them, U k Indicates the node ID k The present application embodiment does not limit this.

[0074] Step S202, when a fault is detected in the target low-voltage distribution network, the nodes and edges in the fault area are removed from the initial directed graph model to obtain a target directed graph model;

[0075] In some embodiments of the present application, when a fault in the distribution network is detected, the power supply capacity assessment system can determine the fault location information of the fault area where the fault occurs in the target low-voltage distribution network, and then can remove the nodes and edges of the fault area from the initial directed graph model based on the fault location information to obtain a target directed graph model, that is, a post-fault directed graph model, so as to avoid searching for power supply recovery paths passing through nodes in the fault area when the target directed graph model is subsequently used for path search. By searching only for paths with directed connections through the directed graph model, the power supply recovery effect can be effectively achieved while improving the power supply recovery efficiency.

[0076] For example, it is assumed that the fault location information set is , where the i-th fault location information f infoi It may contain the suspected fault node number, related line identification and other information, and can locate the i-th fault information f infoito be processed.

[0077] As an example, if the fault location information f infoi contains multiple suspected node numbers, and the most likely faulty node can be determined by comparing the electrical characteristics of the nodes (such as the degree of abnormal voltage and current, etc.). For example, the node The voltage abnormality is ΔU i , the current abnormality is ΔI i , the calculated comprehensive abnormality index can be: , where α and β are weight coefficients, and α+β=1, α>0, β>1, then you can choose the comprehensive abnormality index The largest node is the failed node n fault As another example, if the fault location information f infoi The line identifier is included in the line. At this time, it can be checked whether the information of the nodes at both ends of the line is related to the screened faulty nodes. If the information of the nodes at both ends of the line is related to the screened faulty nodes, it can be determined that the line is a faulty line.

[0078] Furthermore, in order to remove the nodes and edges of the fault area from the initial directed graph model, firstly, the node set and edge set of the fault area may be determined according to the preprocessed fault location information.

[0079] For example, assume that the node set in the fault area is N fault , the edge set of the fault area is E fault , for the faulty node n fault Its electrical related nodes can be considered, for example, fault The set of directly connected nodes is N direct , assuming that the number of nodes connected to the faulty node is n direct ,at this time , assuming that the node set connected to the node connected to the aforementioned fault node and whose voltage change rate exceeds a certain threshold is N indirect , we can determine the node set of the fault area as:

[0080]

[0081] Then, for the node set N fault The nodes in the graph can be used to find the connecting edges between node u and node v. For example, the edge set of the initial directed graph is E initial , then the edge set of the fault area can be: .

[0082] After obtaining the node set and edge set of the fault area, the nodes and edges of the fault area can be removed from the initial directed graph model to obtain a temporary graph model. For example, assuming that the node set of the initial directed graph is N initial , the edge set is E initial , the temporary node set after removal is N temp , the temporary edge set is E temp , then the following relationship exists: .

[0083] After removing the nodes and edges in the faulty area, the temporary graph may become disconnected. In this case, the connectivity of the temporary graph can be checked and processed accordingly. For example, a breadth-first search (BFS) algorithm can be used to traverse the temporary graph, for example, from the node Start BFS, assuming that the set of reachable nodes is N reachable ,like , it means that the temporary graph is not connected. In order to further restore the connectivity, for the disconnected subgraph, the boundary nodes of the two closest subgraphs can be found. and boundary nodes Specifically, suppose the coordinates of node n in the subgraph are (x n ,y n ), boundary node n b1 The coordinates of (x n1 ,y n1 ), boundary node n b2 The coordinates of (x n2 ,y n2 ), boundary node n b1 and boundary node n b2 The distance between these two nodes is , then we can select the two boundary nodes with the smallest distance, for example, add a virtual edge (x b1 ,y b1 )arrive middle.

[0084] Furthermore, for the remaining nodes , its voltage and current will change, and the voltage and current of the remaining nodes can be updated at this time.

[0085] For the voltage and current update, for example, assume that the node The original voltage is U n , the current is I n , the updated voltage and current can be recalculated based on Kirchhoff’s law and network topology, for example, the node and The adjacent nodes are connected, and the set of adjacent nodes is Nadj , then the updated voltage can be:

[0086]

[0087] Among them, node M is the set of adjacent nodes N adj Any node of is the association weight between node n and node M, which can be calculated based on the line resistance R nM and line reactance X nM The specific calculation formula can be expressed as: .

[0088] And, for the remaining nodes The corresponding remaining edges , its current and power will change, and the current and power of the remaining edges can be updated at this time.

[0089] For the update of current and power, for example, assume that the original current of edge (u,v) is , the power is , the updated current and updated power It can be recalculated based on the node voltage and line parameters. The specific formula can be as follows:

[0090]

[0091] in, It means edge u The updated voltage, It represents the updated voltage of edge u. It represents the updated voltage of node n, R uv represents the line resistance of the edge (u,v), X uv represents the line reactance of the edge (u,v), It represents the phase difference of the voltage at both ends of the edge (u,v).

[0092] After the above processing, we finally get the post-fault directed graph model, whose node set can be , the edge set can be , both nodes and edges have updated parameters, completing the transformation from the initial directed graph model to the post-fault directed graph model, thereby obtaining the target directed graph model subsequently applied to path search.

[0093] Step S203, based on the load data of each node in the target low-voltage distribution network and the target directed graph model, a target load node set for priority power restoration in the non-fault area is obtained;

[0094] In some embodiments of the present application, the power supply capacity assessment system can perform load assessment on nodes in non-fault areas of the distribution network based on the load data of each node in the distribution network and a post-fault directed graph model, and obtain a target load node set for prioritizing power supply restoration, thereby performing a path search based on the target directed graph model and the target load node set.

[0095] In some embodiments of the present application, the power supply capacity assessment system can first determine the nodes in the non-fault area in the distribution network, then determine the load data of the nodes in the non-fault area, determine the priority values ​​of the nodes in the non-fault area, and then determine the target load node set based on the determined priority values.

[0096] In practical applications, the power supply capacity assessment system can determine the nodes in the non-fault area of ​​the distribution network based on the post-fault directed graph model and all the nodes in the distribution network, that is, based on the numbering information of each node in the distribution network and each node in the post-fault directed graph model. Specifically, it can be achieved by matching the post-fault directed graph model to the numbering information corresponding to the nodes in the non-fault area of ​​the distribution network. Assume that the node set of the post-fault directed graph model is N final , it means that the node set contains all the nodes in the distribution network that are not affected by the fault.

[0097] After determining the nodes in the non-fault area of ​​the distribution network, the power supply capacity evaluation system can filter out the load data of the nodes in the non-fault area from the load data of the distribution network. For example, the load data of each node may include the real-time load size, load type and load interruption cost of each node. Assuming that the node set of the directed graph model after the fault is N final , the load data set of all nodes in the distribution network is ,in, Indicates The load data of each node, including the real-time load size P loadi , Load type T loadi and load interruption cost C loadi , at this time, the load data set of the non-fault area The formula can be expressed as: .

[0098] In some embodiments of the present application, the power supply capacity assessment system can evaluate the load of nodes in non-fault areas in the distribution network based on the real-time load size, load type and load interruption cost of each node, which can be specifically implemented by determining the target load node set based on the determined priority value.

[0099] Specifically, first, the power supply capacity assessment system can assign initial priority values ​​to nodes in non-fault areas according to the priority relationships corresponding to the load types of the nodes, where the load types include residential loads, commercial loads, and industrial loads, and the residential loads have a higher priority than the commercial loads, and the commercial loads have a higher priority than the industrial loads.

[0100] For example, assuming that the initial priority value of the residential load is , the initial priority value of commercial load is , the initial priority value of industrial load is , for the non-fault area load data set The i-th load data in , its initial priority value The calculation formula can be:

[0101]

[0102] Optionally, the load interruption cost reflects the economic loss or social impact caused by the load outage. The higher the load interruption cost, the higher the priority of restoring power supply. Specifically, the power supply capacity evaluation system can adjust the initial priority value corresponding to the load type of the node in the non-fault area according to the load interruption cost, and obtain the adjusted priority value of the i-th node in the non-fault area. , the specific formula can be shown as follows:

[0103]

[0104] Among them, P basei Refers to the non-fault area load data set The initial priority value of the load data of the i-th node in C laodi Refers to the non-fault area load data set The load interruption cost of the load data of the i-th node in, and Represents the load data set of non-fault area The minimum and maximum values ​​of all load interruption costs in .

[0105] Furthermore, the real-time load size will also affect the priority of power restoration. Generally speaking, a larger load contributes more to the stable operation of the system after power restoration. Specifically, the power supply capacity evaluation system can correct the adjusted priority value of the node in the non-fault area according to the real-time load size to obtain the corrected priority value of the i-th node in the non-fault area. , the specific formula can be shown as follows:

[0106]

[0107] Among them, P adi Refers to the non-fault area load data set The adjusted priority value of the i-th node in laodi Refers to the non-fault area load data set The real-time load size of the load data of the i-th node in, and Represents the load data set of non-fault area The minimum and maximum values ​​of all real-time load sizes in .

[0108] Optionally, in the target directed graph model, i.e., the post-fault directed graph model, the nodes closer to the power supply nodes have relatively less difficulty and risk in restoring power supply, and can be given a higher priority. Specifically, the power supply capacity evaluation system can determine the node distance between the nodes in the non-fault area and the power supply nodes based on the post-fault directed graph model, and optimize the corrected priority value of the nodes in the non-fault area according to the node distance to obtain the final priority value of the nodes in the non-fault area.

[0109] In practical applications, the power supply capacity evaluation system can obtain the node distance between the node in the non-fault area and the power supply node according to the directed graph model after the fault. For example, the node distance can be calculated according to the breadth-first search algorithm. Assume that the node distance can be obtained by the breadth-first search algorithm. To the power node The shortest path length is , the final priority value P finali The specific calculation formula can be:

[0110]

[0111] Among them, P modi Refers to the non-fault area load data set The corrected priority value of the i-th node in d i Refers to the non-fault area load data set The shortest path length from the i-th node to the power node, Represents the load data set of the non-fault area The maximum value of the shortest path length from all nodes to the power node.

[0112] Optionally, nodes with higher final priority values ​​have higher priority in restoring power supply. The power supply capacity evaluation system can determine the target load node based on the final priority value of the node in the non-fault area, which can be specifically expressed as For the non-fault area load data set The load nodes in the , are sorted, and several nodes with the highest final priority values ​​are selected as the target load nodes for priority power restoration. Exemplarily, the target load node set for priority power restoration is L targer , select the final priority value Top The nodes of are taken as the target load node set, The value of can be determined according to the actual situation, that is: .

[0113] The embodiment of the present application can determine a target load node set for prioritizing power supply restoration, so that a depth-first search algorithm can be used in combination with the target load node set to perform multi-objective decision-making evaluation on multiple power supply restoration paths, and the optimal final power supply restoration path can be selected to adapt to the dynamic changes of the power system, ensure the accuracy of the power supply restoration path, and improve the search speed of the power supply restoration path, thereby improving the power supply restoration efficiency.

[0114] Step S204, according to the location and parameters of the distributed device in the target directed graph model, taking the node where the distributed device in the target directed graph model is located as the starting node, performing path search on the target load node set to obtain an initial power supply restoration path;

[0115] Among them, the positions and parameters of distributed devices are marked in the initial directed graph model, and the positions and parameters of distributed devices are also marked in the target directed graph model obtained on the basis of the initial directed graph model; however, the target directed graph model is a post-fault directed graph model, and the positions and parameters of distributed devices in non-fault areas are mainly marked in the target directed graph model to avoid subsequent searches for power supply restoration paths through nodes in the fault area, and to be able to adapt to dynamic changes in the power system, ensure the accuracy of the power supply restoration path, and improve the search speed of the power supply restoration path, thereby improving the power supply restoration efficiency.

[0116] In some instances of the present application, the power supply capacity assessment system can use a depth-first search algorithm to perform a path search starting from the node where the distributed power source or energy storage device is located in the directed graph model after the fault, based on the location and parameters of the distributed power source and energy storage device in the directed graph model after the fault, as well as the target load node for priority power restoration, to find a path that can be connected to the target load node, and the line capacity on the path must meet multiple feasible initial power supply recovery paths that meet the preset load power supply requirements.

[0117] Specifically, first, the power supply capability evaluation system may determine a target node from a set of target load nodes, and then determine an initial power supply restoration path based on the determined target node and a start node.

[0118] The process of determining the target node can be expressed as obtaining the actual required power of each node in the target load node set, and then based on the position of the distributed device in the target directed graph model, selecting the starting node in turn from the node set where the distributed device is located, and performing a depth-first search from each starting node to obtain the currently searched node; then an iterative optimization search can be performed, which is specifically manifested as obtaining the adjacent node set corresponding to the currently searched node, continuing to perform a deep optimization search from each adjacent node in the adjacent node set, and updating the first remaining power supply capacity of the node where the distributed device is located to the second remaining power supply capacity during the search process, until the target node is a node in the target load node set, and the second remaining power supply capacity of the node where the distributed device is located is greater than or equal to the actual required power of the target adjacent node, and the aforementioned target adjacent node that meets the conditions is used as the target node for constructing the initial power supply recovery path.

[0119] In practical applications, before starting the path search, the relevant data structures can be initialized. For example, assuming that the node set of the directed graph model after the fault is , the edge set is , the node set where the distributed power supply and energy storage device are located is , the target load node set for priority power restoration is At this time, the power supply capacity assessment system can initialize the following attributes for each n nodes: access tag , used to mark whether the node has been visited; parent node , used to record the parent node of the node in the search path; at the same time, you can also create an empty feasible path set , used to store the feasible power restoration path finally found.

[0120] The actual required power of each target load node in the target load node set can be determined according to the real-time load size in the load data of each node. For example, assuming that the target load node set is , the i-th target load node in the target load node set is , the real-time load size is , for the actual required power The specific formula can be shown as follows:

[0121]

[0122] in, Indicates the preset margin coefficient, the value range is .

[0123] Furthermore, the power supply capacity evaluation system can be obtained from the node set where the distributed power supply and energy storage device are located. Select nodes one by one As the starting node, a depth-first search is performed from each starting node. It should be noted that before starting the depth-first search, the jth starting node can be Access token and initialize its remaining power supply capacity is the rated power of the distributed power source or energy storage device , that is, the parameter labeling of the node where the distributed device is located in the target directed graph model, can be used to determine the first remaining power supply capacity of the node where the distributed device is located.

[0124] Optionally, the power supply capability assessment system starts from the current starting node After starting the depth-first search to obtain the currently searched node, the adjacent node set corresponding to the currently searched node can be obtained, and for each adjacent node in the adjacent node set corresponding to the currently searched node, according to the line capacity between the currently searched node and the target adjacent node connected to the currently searched node, and the actual required power of the target adjacent node, continue to perform a depth-first search from the target adjacent node to obtain the target node.

[0125] For example, assume that the node currently searched is , the node currently searched The set of adjacent nodes is , s is a positive integer, for the sth adjacent node in the adjacent node set corresponding to the currently searched node , you can do the following: If , that is, the target adjacent node has not been visited yet, then the connection to the currently searched node can be calculated The target neighboring node to which it is connected Line capacity , and perform a depth-first search starting from the target adjacent nodes based on the calculated line capacity.

[0126] As an example, if the target neighbor node , that is, the currently searched node belongs to the target load node set, and the power supply capacity evaluation system can check the currently searched node The current remaining power supply capacity Whether the target adjacent nodes are met The actual power required , and line capacity Whether it meets the actual power demand , that is, to determine whether the following inequality holds:

[0127]

[0128] If the above equation holds true, it means that the target node that meets the power supply conditions is currently searched in the target load node set. , where the power supply condition may refer to the second remaining power supply capacity of the node where the distributed power source or energy storage device is located after the update is greater than or equal to the target node The actual power required .

[0129] If the above inequality holds true, the power supply capability assessment system can update the target adjacent node The parent node of , and update the target adjacent nodes Remaining power supply capacity ,mark , continue from the target adjacent node Start a depth-first search until the target node is found.

[0130] As another example, if the target neighbor node , that is, the currently searched node does not belong to the target load node set. Assuming that the line capacity at this time is Greater than the preset minimum transmission power , then the power supply capability assessment system can update the target adjacent nodes The parent node of And update the target neighboring nodes Remaining power supply capacity ,mark , continue from the node Start a depth-first search until the target node is found.

[0131] In some embodiments of the present application, after searching for the target node, the power supply capacity evaluation system can construct a power supply restoration path from the starting node to the target node based on tracing back the parent node, and can obtain the line capacity of each edge on the power supply restoration path and the cumulative demand power of all target load nodes passed from the starting node to the current edge, and determine the initial power supply restoration path based on the line capacity of each edge on the power supply restoration path and the cumulative demand power of at least one target load node passed from the starting node to the current edge.

[0132] Exemplarily, the power supply capacity evaluation system can construct a power supply capacity evaluation system from the starting node by tracing back to the parent node. To the target node The power supply restoration path is assumed to be , for each edge on the power restoration path , you can check the line capacity at this time Whether the cumulative power demand from the starting node to all target load nodes passed by the current edge can always be met , where the cumulative power demand The calculation formula can be shown as follows:

[0133]

[0134] If all edges on the power restoration path satisfy , then determine the path It is feasible, and it can be added to the set of feasible paths. In this paper, multiple feasible initial power supply restoration paths are obtained.

[0135] Step S205, evaluating each initial power restoration path according to the path information of each initial power restoration path to obtain a target power restoration path;

[0136] In some embodiments of the present application, after using a depth-first search algorithm to search for multiple feasible power restoration paths, the power supply capability evaluation system can evaluate the multiple feasible power restoration paths to obtain the final selected target power restoration path, and can perform a global search in a complex distribution network environment to avoid falling into local optimality and achieve better power restoration effects.

[0137] Optionally, the path information may include path length, line remaining capacity and power recovery time. After finding multiple initial power recovery paths, the power supply capacity assessment system can conduct a comprehensive assessment of each initial power recovery path based on the path length, line remaining capacity and power recovery time of the initial power recovery path, and select the path with the best comprehensive assessment as the power recovery path set, thereby obtaining the target power recovery path.

[0138] Specifically, first, the power supply capacity assessment system can determine the comprehensive assessment indicators of each initial power supply restoration path according to the path length, line remaining capacity and power supply restoration time of each initial restoration path, and then can select the target power supply restoration path based on the determined comprehensive assessment indicators.

[0139] The calculation process of the comprehensive evaluation index can be specifically expressed as follows: for each initial power supply restoration path, the path length is determined according to the number of nodes, and the remaining capacity of the line is determined based on the path length and the rated capacity of each edge and the current transmitted power. Then, the power supply restoration time is determined based on the path length, line transmission speed and switch operation time. Finally, the comprehensive evaluation index of each initial power supply restoration path is determined based on the path length, remaining capacity of the line and power supply restoration time.

[0140] The path length can be determined based on the number of nodes of each initial power restoration path. , whose path length is the number of edges included in the path. The power supply capability evaluation system can determine the path length according to the number of nodes in each initial power supply restoration path. For example, assuming that the initial power supply restoration path , then the initial power supply restoration path The path length Can be: ,in, Is the initial power restoration path The number of nodes in .

[0141] The remaining capacity of the line can be determined based on the path length and the rated capacity of each edge included and the current transmitted power. Specifically, the power supply capacity assessment system can obtain the initial power supply restoration path The jth edge in Rated capacity and the current transmitted power , and then restore the path according to the initial power supply The path length and initial power restoration path The jth edge in Rated capacity and the current transmitted power , determine the initial power restoration path The remaining capacity of the line For example, the rated capacity of the line is a known fixed value, and the current transmitted power can be calculated based on the previous load distribution and the power conditions of other nodes in the path. The specific formula for the remaining capacity of the line can be expressed as: .

[0142] Power restoration time is affected by many factors, including path length. , line transmission speed (different lines have different transmission speeds), switch operation time, and the number of switch operations in the path, etc. Specifically, the power supply capability evaluation system can obtain the total switch operation time and path transmission time of the initial power supply restoration path to determine the power supply restoration time.

[0143] The total switch operation time of the initial power restoration path may be determined based on the number of switch operations in the initial power restoration path and the path transmission time.

[0144] Exemplarily, the power supply capability assessment system may obtain the i-th initial power supply restoration path Line transmission speed , according to the i-th initial power supply restoration path The length of the jth edge and the line transmission speed , calculate the path transmission time , the specific formula can be: in, represents the jth edge The length of the path; then the number of switch operations in the path can be obtained , according to the initial power restoration path Number of switch operations in the diameter and switch operation time , calculate the total switching operation time , and then according to the initial power supply recovery path Total switching time and path transmission time The power supply restoration time of the i-th initial power supply restoration path is determined as: .

[0145] Furthermore, the power supply capacity evaluation system determines the comprehensive evaluation index of the i-th initial power supply restoration path according to the path length, line remaining capacity and power supply restoration time of each initial power supply restoration path. , the specific formula is as follows:

[0146]

[0147] Among them, L tempi refers to the path length of the i-th initial power restoration path, C totali refers to the remaining capacity of the i-th initial power restoration path, is the maximum value of the remaining capacity of the line in all paths, T i refers to the power supply restoration time of the i-th initial power supply restoration path, It is the maximum value of the power restoration time among all paths.

[0148] In some embodiments of the present application, after obtaining the comprehensive evaluation indicators of each initial power restoration path, the power supply capacity evaluation system can traverse the comprehensive evaluation indicators of all initial power restoration paths, and calculate the voltage level and power distribution of each node after power restoration for each path in the power restoration path set, to determine whether the preset safety operation requirements are met.

[0149] In practical applications, the power supply capacity evaluation system traverses the comprehensive evaluation indicators of each initial power supply restoration path, sorts each initial power supply restoration path in a preset order, and obtains a path sequence, wherein the preset order may be a descending order. At this time, the initial power supply restoration path at the first position in the path sequence may be determined as the first path, that is, the largest comprehensive evaluation indicator may be The corresponding initial power restoration path is determined as the first path , and for the first path Determine whether the preset safety operation requirements are met.

[0150] Optionally, the preset condition is that the voltage level is within a preset range, e.g. ; and the power is less than the preset power threshold, for example It should be noted that for the preset range and preset power thresholds It can be determined based on actual conditions, and the embodiments of the present application are not limited to this.

[0151] For the first path , the voltage level of each node after power supply is restored can be calculated. Specifically, according to Kirchhoff's law and Ohm's law, for the node , its voltage It can be calculated by the following recursive formula (the power node voltage is ),but ,in, It is through the edge The current, It is the edge impedance; in terms of power distribution, for the edge , its transmission power can be: It should be noted that is through node n k-1 With node n k-1 Connected edges.

[0152] As an example, if the voltage level of each node and the power of each edge of the first path meet the preset conditions after the power supply is restored, that is, the first path After power is restored, the voltage of each node satisfy , and the first path The transmission power of each edge after power is restored satisfy , the first path can be determined as the target power supply restoration path.

[0153] As another example, if the voltage level of each node and / or the power of each edge of the first path does not meet the preset conditions after the power supply is restored, that is, the first path After power is restored, the voltage of each node Dissatisfied , and / or, the first path The transmission power of each edge after power is restored Dissatisfied , then the suboptimal path can be reselected, and the reselected suboptimal path is judged to see whether it meets the preset safety operation requirements, until it meets the requirements, and the final target power supply restoration path is obtained. Specifically, when the preset conditions are not met, the following steps are repeated: reselect the power supply restoration path from the remaining paths except the first path in a preset order, that is, select the comprehensive evaluation index E from the remaining paths except the first path. i The second highest initial power supply restoration path is used as the new power supply restoration path, and the voltage level of each node and the power of each edge of the new power supply restoration path after power is restored are calculated, and it is determined whether the voltage level of each node and the power of each edge of the new power supply restoration path after power is restored meet the preset conditions, until the voltage level and power of the new power supply restoration path meet the preset conditions, and the new power supply restoration path is determined as the target power supply restoration path.

[0154] Step S206, based on the post-recovery operating state of the target low-voltage distribution network after executing the target power supply recovery path, the power supply capacity of the target low-voltage distribution network is evaluated to obtain a power supply capacity evaluation value of the target low-voltage distribution network.

[0155] In some embodiments of the present application, after selecting the optimal final power supply restoration path, the power supply capacity evaluation system can execute the finally selected target power supply restoration path to restore power to the faulty target low-voltage distribution network, obtain the operating status of the target low-voltage distribution network after power is restored, and based on the restored operating status, evaluate the power supply capacity of the target low-voltage distribution network's ability to quickly restore power after a fault.

[0156] Specifically, the power supply restoration capability index of the target low-voltage distribution network can be determined according to the operating status of the target low-voltage distribution network after restoration, and then the power supply capability of the target low-voltage distribution network can be evaluated according to the power supply restoration capability index to obtain a power supply capability evaluation value of the target low-voltage distribution network; the power supply capability evaluation value is used to indicate the ability to quickly restore power supply after a fault.

[0157] Exemplarily, the power supply restoration capability index may include the load ratio of the target low-voltage distribution network to restore power supply, the power supply restoration time, and the voltage qualification rate after power supply restoration.

[0158] Optionally, the load proportion of the target low-voltage distribution network restoring power supply can be determined based on the restored power supply load obtained after executing the target power supply restoration path and the total grid load in the non-fault area of ​​the distribution network.

[0159] For example, assume that the set of all nodes in the directed graph model after the failure is , the set of restored power supply nodes is , where the set of restored power supply nodes Refers to the set of nodes passed through in the target power restoration path that is finally executed.

[0160] After executing the final power restoration path, the power supply capability evaluation system can obtain the set of restored power supply nodes. The node load of each restored power supply node in the fault-tolerant directed graph model is calculated, and the restored power supply load is determined according to the node load of each restored power supply node; and, according to the set of all nodes in the directed graph model after the fault, The node load of each node in the distribution network is calculated to calculate the total load of the power grid in the non-fault area, and then the load proportion of power supply restoration is determined according to the restored power supply load and the total load of the power grid in the non-fault area of ​​the distribution network. , the specific formula can be shown as follows:

[0161]

[0162] in, Indicates that the power supply node is restored. Indicates that the power supply node is restored The node load, Represents the first part of the directed graph model after the fault nodes, Representation Node Node load.

[0163] Optionally, the power restoration time may be determined based on a first time of executing the final power restoration path and a second time of successfully restoring power to all restored power nodes in the target power restoration path after executing the target power restoration path.

[0164] Exemplarily, the power supply capability evaluation system can record the time from the start of the power restoration operation to the time when all restored power supply nodes successfully restore power during the execution of the target power supply restoration path, that is, the first time of executing the target power supply restoration path, and the second time when all restored power supply nodes in the final power supply restoration path successfully restore power after executing the target power supply restoration path, and then the power supply capability evaluation system can record the time from the start of the power restoration operation to the time when all restored power supply nodes successfully restore power according to the first time. and the second time Determine the restoration time for power supply restoration .

[0165] Optionally, the voltage qualification rate can be determined based on a first number of restored power supply nodes whose actual voltages obtained after executing the target power supply restoration path are within a preset voltage qualification range, and a second number of nodes in the target power supply restoration path.

[0166] Specifically, the power supply capability evaluation system may firstly obtain the actual voltage of the restored power supply node after executing the target power supply restoration path.

[0167] Exemplarily, the power supply capability evaluation system may obtain a set of restored power supply nodes after executing the target power supply restoration path. Each restored power node in The actual voltage of the node for restoring power supply Each restored power node in , according to the circuit principle and the line parameters (resistance Reactance ) and the supply voltage , calculate the actual voltage by the following recursive formula For example, from the power supply node to the power restoration node The path passed is a series of edges. The current of each edge can be calculated through multiple iterations of Ohm's law and Kirchhoff's law to finally obtain the power supply restoration node. The actual voltage It should be noted that the calculation process of the current of each edge may refer to the above-mentioned recursive formula based on Kirchhoff's law and Ohm's law, and the embodiment of the present application will not be elaborated here.

[0168] After obtaining the actual voltage of the restored power supply node after executing the target power supply recovery path, the power supply capability assessment system can determine the first number of restored power supply nodes whose actual voltage is within a preset voltage qualification range, and the second number of restored power supply nodes in the final power supply recovery path, and determine the voltage qualification rate after power restoration based on the first number and the second number, that is, voltage qualification rate = first number / second number.

[0169] In some embodiments of the present application, the power supply capacity evaluation process based on the power supply recovery capacity index can be expressed as determining the load proportion deviation, power supply recovery time deviation and voltage qualification rate deviation respectively based on the load proportion, power supply recovery time and voltage qualification rate, and the ideal recovery load proportion, ideal power supply recovery time and ideal recovery voltage qualification rate under the ideal recovery state; then, based on the load proportion deviation, power supply recovery time deviation and voltage qualification rate deviation, determine the comprehensive deviation index, and perform power supply capacity evaluation based on the comprehensive deviation index to obtain the power supply capacity evaluation value of the target low-voltage distribution network.

[0170] Optionally, the power supply capacity evaluation system can determine the load ratio deviation based on the load ratio and the ideal recovery load ratio under the ideal recovery state. , the specific formula can be shown as follows:

[0171]

[0172] Among them, R load Indicates the actual recovery load ratio under the actual recovery state, Indicates the ideal recovery load ratio under ideal recovery conditions, usually .

[0173] Furthermore, the power supply capacity evaluation system can determine the power supply recovery time deviation according to the power supply recovery time and the ideal power supply recovery time under the ideal recovery state. , the specific formula can be shown as follows:

[0174]

[0175] Among them, T restored Indicates the actual power restoration time under the actual restoration state. Indicates the ideal power restoration time under ideal restoration conditions.

[0176] Furthermore, the power supply capability evaluation system can determine the negative voltage qualification rate deviation according to the voltage qualification rate and the ideal recovery voltage qualification rate under the ideal recovery state. , the specific formula can be shown as follows:

[0177]

[0178] in, Indicates the voltage qualification rate, Indicates the ideal recovery voltage qualification rate under ideal recovery conditions.

[0179] Furthermore, the power supply capacity evaluation system can determine the comprehensive deviation index based on the load ratio deviation, power supply recovery time deviation and voltage qualification rate deviation. , the specific formula can be shown as follows:

[0180]

[0181] Furthermore, the power supply capacity evaluation system can determine the power supply capacity evaluation value according to the comprehensive deviation index. ,in, .

[0182] It should be noted that the power supply capacity assessment value The closer it is to 1, the stronger the target low-voltage area distribution network's ability to quickly restore power supply after a fault. The closer it is to 0, the weaker the ability to quickly restore power supply after a fault.

[0183] The embodiment of the present application evaluates the ability of the distribution network to quickly restore power supply after a fault by using load proportion, power restoration time and voltage qualification rate, thereby improving the accuracy of the power supply restoration capability assessment.

[0184] In an embodiment of the present application, when a fault is detected in the target low-voltage distribution network, a target directed graph model that takes into account the positions and parameters of distributed devices in non-fault areas is adopted. Starting from the nodes where the distributed devices are located in the target directed graph model, a path search is performed on the target load node set to obtain a target power supply recovery path for use in evaluating the power supply capacity of the target low-voltage distribution network that executes the power supply recovery path. This not only ensures that the searched target power supply recovery path can adapt to the dynamic changes of the power system while reflecting the operating status of the distribution network based on the marked positions and parameters, but also ensures the accuracy of the evaluation of the ability to quickly restore power supply after the distribution network fault is restored, thereby achieving the accuracy and effectiveness of power supply recovery and improving the power supply reliability of the low-voltage distribution network. The target directed graph model can also be used to search only paths with directed connections during the path search process, without the need to search all paths, thereby improving the recovery efficiency of the low-voltage distribution network.

[0185] It should be noted that, for the method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present application are not limited by the described order of actions, because according to the embodiments of the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present application.

[0186] Reference Figure 3 , shows a structural block diagram of a low-voltage distribution network power supply capacity evaluation device provided in an embodiment of the present application, which is applied to a power supply capacity evaluation system and may specifically include the following modules:

[0187] The directed graph model acquisition module 301 is used to acquire a target directed graph model when a fault is detected in the target low-voltage distribution network; the target directed graph model is a directed graph model after the nodes and edges in the fault area are removed from the initial directed graph model, and the location and parameters of the distributed devices in the non-fault area are marked in the target directed graph model;

[0188] A load node acquisition module 302 is used to acquire a target load node set for priority power restoration in a non-fault area based on load data of each node in the target low-voltage distribution network and a target directed graph model;

[0189] The path search module 303 is used to perform path search starting from the node where the distributed device is located in the target directed graph model according to the location and parameters of the distributed device in the target directed graph model and the target load node set, so as to obtain the target power supply restoration path;

[0190] The power supply capacity evaluation module 304 is used to evaluate the power supply capacity of the target low-voltage distribution network based on the restored operating status of the target low-voltage distribution network after executing the target power supply recovery path, and obtain a power supply capacity evaluation value of the target low-voltage distribution network; the power supply capacity evaluation value is used to indicate the ability to quickly restore power supply after a fault.

[0191] In some embodiments of the present application, the path search module 303 may include the following submodules:

[0192] The power supply restoration path search submodule is used to perform path search on the target load node set according to the location and parameters of the distributed equipment in the target directed graph model, taking the node where the distributed equipment is located in the target directed graph model as the starting node, and obtain the initial power supply restoration path; based on the path information of each initial power supply restoration path, each initial power supply restoration path is evaluated to obtain the target power supply restoration path.

[0193] In some embodiments of the present application, the parameter is used to determine the first remaining power supply capacity of the node where the distributed device is located; the power supply recovery path search submodule may include the following units:

[0194] The initial power supply recovery path search unit is used to obtain the actual required power of each node in the target load node set; based on the position of the distributed device in the target directed graph model, the starting node is selected from the node set where the distributed device is located in turn, and a depth-first search is performed from each starting node to obtain the currently searched node; the adjacent node set corresponding to the currently searched node is obtained, and the depth optimization search is continued from each adjacent node in the adjacent node set, and the first remaining power supply capacity is updated to the second remaining power supply capacity during the search process until the target adjacent node is a node in the target load node set, and the second remaining power supply capacity is greater than or equal to the actual required power of the target adjacent node, and the target adjacent node is used as the target node; based on the target node and the starting node, the initial power supply recovery path is determined.

[0195] In some embodiments of the present application, the initial power restoration path search unit may include the following subunits:

[0196] The target node determination subunit is used to continue to perform a depth-first search from the target adjacent node for each adjacent node in the adjacent node set corresponding to the currently searched node, according to the line capacity between the currently searched node and the target adjacent node connected to the currently searched node, and the actual required power of the target adjacent node.

[0197] In some embodiments of the present application, the initial power restoration path search unit may include the following subunits:

[0198] The initial power supply restoration path construction subunit is used to construct a power supply restoration path from the starting node to the target node based on the backtracking parent node method; based on the line capacity of each edge on the power supply restoration path and the cumulative required power of at least one target load node passed from the starting node to the current edge, the initial power supply restoration path is determined.

[0199] In some embodiments of the present application, the path information includes the path length, the remaining capacity of the line, and the power supply recovery time; the power supply recovery path search submodule may include the following units:

[0200] A target power supply restoration path search unit is used to determine the comprehensive evaluation index of each initial power supply restoration path according to the path length, line remaining capacity and power supply restoration time of each initial restoration path; traverse the various comprehensive evaluation indicators of each initial power supply restoration path, sort each initial power supply restoration path in a preset order, and obtain a path sequence; determine the initial power supply restoration path that is at the first position in the path sequence as the first path; if the voltage level of each node and the power of each edge of the first path after power supply is restored meet the preset conditions, then determine the first path as the target power supply restoration path; wherein the preset conditions are that the voltage level is within a preset range and the power is less than a preset power threshold; and / or, if the voltage level of each node and / or the power of each edge of the first path after power supply is restored do not meet the preset conditions, then reselect the power supply restoration path from the remaining paths except the first path in a preset order until the voltage level and power of the new power supply restoration path meet the preset conditions, and determine the new power supply restoration path as the target power supply restoration path.

[0201] In some embodiments of the present application, the power supply capability evaluation module 304 may include the following submodules:

[0202] The power supply capacity evaluation submodule is used to determine the power supply recovery capacity index of the target low-voltage distribution network based on the post-recovery operating status of the target low-voltage distribution network; the power supply recovery capacity index includes the load proportion of the target low-voltage distribution network that restores power supply, the power supply recovery time and the voltage qualification rate after the power supply is restored; based on the load proportion, the power supply recovery time and the voltage qualification rate, and the ideal restored load proportion, ideal power supply recovery time and ideal restored voltage qualification rate under the ideal recovery state, the load proportion deviation, the power supply recovery time deviation and the voltage qualification rate deviation are determined respectively; based on the load proportion deviation, the power supply recovery time deviation and the voltage qualification rate deviation, the comprehensive deviation index is determined; the power supply capacity is evaluated based on the comprehensive deviation index to obtain the power supply capacity evaluation value of the target low-voltage distribution network.

[0203] In an embodiment of the present application, when a fault is detected in the target low-voltage distribution network, a target directed graph model that takes into account the positions and parameters of distributed devices in non-fault areas is adopted. Starting from the nodes where the distributed devices are located in the target directed graph model, a path search is performed on the target load node set to obtain a target power supply recovery path for use in evaluating the power supply capacity of the target low-voltage distribution network that executes the power supply recovery path. This not only ensures that the searched target power supply recovery path can adapt to the dynamic changes of the power system while reflecting the operating status of the distribution network based on the marked positions and parameters, but also ensures the accuracy of the evaluation of the ability to quickly restore power supply after the distribution network fault is restored, thereby achieving the accuracy and effectiveness of power supply recovery and improving the power supply reliability of the low-voltage distribution network. The target directed graph model can also be used to search only paths with directed connections during the path search process, without the need to search all paths, thereby improving the recovery efficiency of the low-voltage distribution network.

[0204] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0205] The present application also provides an electronic device, referring to Figure 4 The electronic device 400 provided includes a memory 410, a processor 420, and a computer program 411 stored in the memory 410 and capable of running on the processor 420. When the computer program 411 is executed by the processor, each process of the embodiment of the method for evaluating the power supply capacity of the above-mentioned low-voltage distribution network is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0206] The present application also provides a computer-readable storage medium. Figure 5 The computer readable storage medium 500 provided stores a computer program 411. When the computer program 411 is executed by the processor, the various processes of the above-mentioned low-voltage distribution network power supply capacity evaluation method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0207] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0208] It should be noted that the terms "first", "second", etc. in the specification and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described here can be implemented in an order other than the content illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device including a series of steps or modules need not be limited to those steps or modules clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products or devices. The division of the modules that appear in the embodiments of the present application is only a logical division. There may be other division methods when implemented in practical applications, such as multiple modules can be combined or integrated into another system, or some features can be ignored, or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, and the indirect coupling or communication connection between modules can be electrical or other similar forms, which are not limited in the embodiments of the present application. Furthermore, the modules or sub-modules described as separate components may or may not be physically separated, may or may not be physical modules, or may be distributed in multiple circuit modules, and some or all of the modules may be selected according to actual needs to achieve the purpose of the embodiment of the present application.

[0209] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0210] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0211] In the several embodiments provided in the embodiments of the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0212] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0213] In addition, each functional module in each embodiment of the present application can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0214] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0215] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a server, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server, or data center. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0216] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0217] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded into a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable terminal device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0218] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0219] Finally, it should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0220] The technical solutions provided in the embodiments of the present application are introduced in detail above. The principles and implementation methods of the embodiments of the present application are explained by using specific examples in the embodiments of the present application. The description of the above embodiments is only used to help understand the methods and core ideas of the embodiments of the present application. At the same time, for those skilled in the art, according to the ideas of the embodiments of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the embodiments of the present application.

Claims

1. A method for evaluating the power supply capacity of a low voltage distribution network, characterized in that: The method comprises: When a fault is detected in the target low-voltage distribution network, a target directed graph model is obtained; the target directed graph model is a directed graph model after the nodes and edges in the fault area are removed from the initial directed graph model, and the positions and parameters of the distributed devices in the non-fault area are marked in the target directed graph model; Based on the load data of each node in the target low-voltage distribution network and the target directed graph model, a target load node set for priority power restoration in the non-fault area is obtained; According to the position and parameters of the distributed device in the target directed graph model and the target load node set, a path search is performed starting from the node where the distributed device in the target directed graph model is located to obtain a target power supply restoration path; Based on the post-recovery operating status of the target low-voltage distribution network after executing the target power supply recovery path, a power supply capacity evaluation is performed on the target low-voltage distribution network to obtain a power supply capacity evaluation value of the target low-voltage distribution network; the power supply capacity evaluation value is used to indicate the ability to quickly restore power supply after a fault.

2. The method according to claim 1, characterized in that According to the position and parameters of the distributed device in the target directed graph model and the target load node set, a path search is performed starting from the node where the distributed device is located in the target directed graph model to obtain a target power supply restoration path, including: According to the position and parameters of the distributed device in the target directed graph model, taking the node where the distributed device in the target directed graph model is located as the starting node, performing path search on the target load node set to obtain an initial power supply restoration path; Each initial power restoration path is evaluated according to path information of each initial power restoration path to obtain a target power restoration path.

3. The method according to claim 2, characterized in that The parameter is used to determine the first remaining power supply capacity of the node where the distributed device is located; the path search is performed on the target load node set based on the position and parameters of the distributed device in the target directed graph model, taking the node where the distributed device is located in the target directed graph model as the starting node, to obtain the initial power supply recovery path, including: Obtaining the actual required power of each node in the target load node set; Based on the position of the distributed device in the target directed graph model, selecting a starting node from the node set where the distributed device is located in sequence, and performing a depth-first search starting from each starting node to obtain a currently searched node; Obtain the adjacent node set corresponding to the currently searched node, continue to perform deep optimization search starting from each adjacent node in the adjacent node set, and update the first remaining power supply capacity to the second remaining power supply capacity during the search process, until the target adjacent node is a node in the target load node set, and the second remaining power supply capacity is greater than or equal to the actual required power of the target adjacent node, and the target adjacent node is used as the target node; An initial power restoration path is determined based on the target node and the start node.

4. The method according to claim 3, characterized in that The continuing to perform the deep optimization search starting from each adjacent node in the adjacent node set includes: For each adjacent node in the adjacent node set corresponding to the currently searched node, continue to perform depth-first search from the target adjacent node based on the line capacity between the currently searched node and the target adjacent node connected to the currently searched node, and the actual required power of the target adjacent node.

5. The method according to claim 3, characterized in that: The target load node set includes at least one target load node; and determining the initial power supply restoration path based on the target node and the start node includes: Based on the backtracking parent node method, construct a power supply restoration path from the start node to the target node; The initial power restoration path is determined based on the line capacity of each edge on the power restoration path and the accumulated required power of at least one of the target load nodes passed from the starting node to the current edge.

6. The method according to claim 2, characterized in that The path information includes path length, line remaining capacity and power supply restoration time; the evaluating each initial power supply restoration path according to the path information of each initial power supply restoration path to obtain the target power supply restoration path includes: Determine the comprehensive evaluation index of each initial power supply restoration path according to the path length, line remaining capacity and power supply restoration time of each initial restoration path; Traversing each comprehensive evaluation index of each initial power supply restoration path, sorting each initial power supply restoration path according to a preset order, and obtaining a path sequence; Determine the initial power supply restoration path that is at the first position in the path sequence as the first path; If the voltage level of each node and the power of each edge of the first path after power supply is restored meet preset conditions, the first path is determined as the target power supply restoration path; wherein the preset conditions are that the voltage level is within a preset range and the power is less than a preset power threshold; And / or, if the voltage level of each node and / or the power of each edge of the first path does not meet the preset conditions after power supply is restored, the power supply restoration path is reselected from the remaining paths except the first path in the preset order until the voltage level and power of the new power supply restoration path meet the preset conditions, and the new power supply restoration path is determined as the target power supply restoration path.

7. The method according to claim 1, characterized in that The step of evaluating the power supply capacity of the target low-voltage distribution network based on the post-recovery operating state of the target low-voltage distribution network after executing the target power supply recovery path to obtain a power supply capacity evaluation value of the target low-voltage distribution network includes: Based on the post-restored operating state of the target low-voltage distribution network, determine the power supply restoration capability index of the target low-voltage distribution network; the power supply restoration capability index includes the load proportion of the target low-voltage distribution network that restores power supply, the power supply restoration time, and the voltage qualification rate after the power supply is restored; Based on the load ratio, the power supply restoration time and the voltage qualification rate, and the ideal restored load ratio, the ideal power supply restoration time and the ideal restored voltage qualification rate under the ideal restoration state, respectively determine the load ratio deviation, the power supply restoration time deviation and the voltage qualification rate deviation; Determining a comprehensive deviation index based on the load ratio deviation, the power supply restoration time deviation and the voltage qualification rate deviation; The power supply capacity is evaluated based on the comprehensive deviation index to obtain a power supply capacity evaluation value of the target low-voltage distribution network.

8. A device for evaluating the power supply capacity of a low voltage distribution network, characterized in that: The device comprises: A directed graph model acquisition module is used to acquire a target directed graph model when a fault is detected in the target low-voltage distribution network; the target directed graph model is a directed graph model after the nodes and edges in the fault area are removed from the initial directed graph model, and the location and parameters of the distributed devices in the non-fault area are marked in the target directed graph model; A load node acquisition module, used to acquire a target load node set for priority power restoration in the non-fault area based on the load data of each node in the target low-voltage distribution network and the target directed graph model; A path search module, configured to perform a path search starting from the node where the distributed device is located in the target directed graph model according to the location and parameters of the distributed device in the target directed graph model and the target load node set, to obtain a target power supply restoration path; A power supply capacity evaluation module is used to evaluate the power supply capacity of the target low-voltage distribution network based on the post-recovery operating status of the target low-voltage distribution network after executing the target power supply recovery path, and obtain a power supply capacity evaluation value of the target low-voltage distribution network; the power supply capacity evaluation value is used to indicate the ability to quickly restore power supply after a fault.

9. An electronic device, characterized in that: include: A processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein when the computer program is executed by the processor, the method for evaluating the power supply capacity of a low-voltage distribution network as claimed in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for evaluating the power supply capacity of a low-voltage distribution network as described in any one of claims 1 to 7 is implemented.

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