A power distribution network key device identification method and system for regional network attacks

Abstract

The application discloses a power distribution network key equipment identification method and system for regional network attacks, and relates to the technical field of smart grids, and comprises the following steps: based on a power distribution network topology model, identifying a power distribution network wiring mode, and obtaining a power supply path of a regional power distribution network user; based on the power supply path, obtaining an optimal network attack reachable power distribution line switch formation dataset, forming a first scheme with minimum output additional loss, and finding a second scheme with the least number of switches according to an iterative optimization algorithm; and identifying power distribution network key equipment according to the first scheme or the second scheme. Through the iterative optimization algorithm, the action of the power distribution line switch is determined to simulate a power cut scheme of a network attack implemented by an attacker on the regional power distribution network, and thus effective protection measures can be formulated in advance, so that the safety defense capability of the power distribution network is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smart grid, in particular to a power distribution network key device identification method and system for regional network attacks. BACKGROUND

[0002] With the rapid development of smart grid, power distribution network security problems have been widely concerned. As the end link of the power system, the power distribution network connects a large number of users and bears an important role in power supply. However, the in-depth application of information technology and communication technology not only improves the intelligent level of the power distribution network, but also makes it face higher risk of network attacks. The power distribution network has the characteristics of multiple voltage levels, complex structure, diverse device types, and relatively weak security environment, which reduces the difficulty of network attacks by attackers. In the power system, network attacks on the power distribution network generally target its vulnerable devices or key devices, including substations, switch devices, power distribution automation devices, and remote terminals. Once the key devices are attacked, it may cause widespread power outages, serious economic losses, and even threaten social stability. Therefore, accurately identifying the key devices in the power distribution network and taking effective protection in advance is the key to resisting network attacks and reducing the risk of the power distribution system. This not only helps to improve the security and reliability of the power distribution network, but also has important significance for ensuring the stable operation of the power system.

[0003] In modern power systems, due to the lack of sufficient physical or network isolation of some devices in the power distribution network, attackers may exploit this vulnerability to obtain network information and implement remote attacks. For example, when the communication protocol used by the power distribution network does not take effective encryption and authentication measures, attackers can identify and control devices through man-in-the-middle attacks, replay attacks, and other means. These security risks significantly increase the risk of network attacks on the power distribution network, posing a potential threat to the stability and reliability of the power system. Therefore, taking effective isolation protection measures in advance for key devices and optimizing the encryption and authentication mechanism of the communication protocol are key means to improve the network security level of the power distribution network.

[0004] Existing technologies mainly focus on the identification of key devices in the power system, providing certain theoretical basis for formulating protection strategies to resist network attacks in the power system. However, most current researches mainly focus on the identification of key devices in the entire power distribution network under network attacks, with few studies on the identification of key devices in the power distribution network under regional network attacks. With the continuous breakthrough and rapid development of network attack technology, the probability of precise network attacks on specific local areas of the power distribution network and causing its failure significantly increases. Therefore, it is urgent to develop a key device identification method for local network attacks to effectively improve the security protection capability and overall reliability of the power distribution network. SUMMARY

[0005] To solve the above problems, the purpose of the present application is to provide a power distribution network key device identification technology for regional network attacks, aiming to improve the security defense capability of the power distribution network.

[0006] In order to achieve the above technical purpose, the present application provides a power distribution network key device identification method for regional network attacks, comprising the following steps:

[0007] Based on the power distribution network topology model, the power distribution network wiring mode is identified, and the power supply path of the regional power distribution network user is obtained;

[0008] Based on the power supply path, the optimal network attack reachable power distribution line switch formation dataset is obtained, the first scheme with the minimum output additional loss is formed, and the second scheme with the least number of switches is found according to the iterative optimization algorithm;

[0009] According to the first scheme or the second scheme, the power distribution network key device is identified.

[0010] Preferably, in the process of obtaining the power distribution network topology model, the power distribution network is topologically modeled based on the complex network theory research.

[0011] Preferably, in the process of obtaining the power supply path of the regional power distribution network user, all the associated feeder lines of the target region are modeled as an undirected graph; all the key users in the target region are taken as initial nodes, and the circuit breakers of all the power distribution transformers on the feeder lines and the tie feeder lines of the users are taken as targets; according to different network structures and tie switch types, the minimum path algorithm is used to search from the initial nodes to the targets respectively, to obtain all the minimum paths that can supply power to the important users in the target region, and to form a minimum path table as the power supply path of the regional power distribution network user.

[0012] Preferably, in the process of obtaining the first scheme, it is checked according to the upstream and downstream relationship whether there is a network attack target switch upstream of other network attack target switches, if there is, all the network attack target switches downstream of the switch are deleted, and then it is checked whether there is another switch that can replace the existing switch combination to simplify the switch, to form the first scheme.

[0013] Preferably, in the process of using the iterative optimization algorithm, the network attack reachable power distribution line switches on the power supply path are sorted and screened to obtain an initial solution, the quality of the initial solution is gradually optimized through the iterative optimization algorithm by repeating a specific step; in each iteration, a possibly better solution is generated using the information of the current solution until the stop condition is met.

[0014] Preferably, in the second scheme, the switch obtained in the additional loss minimum scheme is taken as a target switch, and importance degree sorting is performed; the optimal network attack reachable distribution line switch is selected according to the importance degree sorting and the position information of the switch in the feeder; the target area power failure condition is evaluated to determine whether the target area has cut off all power supply paths, if yes, the current all target switches are taken as output and provided to the user, if no, the loop is returned to continue to obtain the second scheme with the least number of switches.

[0015] Preferably, in the identification of the distribution network key equipment, the additional additional loss caused by the second scheme is compared with the first scheme, if the additional additional loss is greater than twice the target, the additional loss minimum scheme is taken as the optimal scheme, otherwise, the attack switch number minimum scheme is taken as the output, and the output result is used to identify the distribution network key equipment.

[0016] The application discloses a distribution network key equipment identification system for regional network attacks.

[0017] The path planning module is used for identifying a distribution network wiring mode based on a distribution network topology model, and obtaining a power supply path of a regional distribution network user.

[0018] The scheme obtaining module is used for obtaining an optimal network attack reachable distribution line switch to form a data set, forming a first scheme with minimum output additional loss, and finding a second scheme with the least number of switches based on an iterative optimization algorithm.

[0019] The identification module is used for identifying the distribution network key equipment according to the first scheme or the second scheme.

[0020] The application discloses the following technical effects:

[0021] The application can simulate the power failure scheme of the attacker for the regional distribution network by the iterative optimization algorithm and the decision of the distribution line switch action, so that effective protection measures can be prepared in advance, and the safety defense capability of the distribution network is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0023] Figure 1 The node system diagram is described in the application;

[0024] Figure 2 is a radial distribution network topology according to the present application;

[0025] Figure 3 is a radial distribution network topology according to the present application;

[0026] Figure 4 is a radial distribution network topology according to the present application;

[0027] Figure 5 is a radial distribution network topology according to the present application;

[0028] Figure 6 is an ATS automatic transfer switch schematic diagram according to the present application;

[0029] Figure 7 is a method flowchart according to the present application. DETAILED DESCRIPTION

[0030] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0031] As shown in Figures 1-7 , the present application provides a power distribution network key equipment identification technology for regional network attacks. Based on the topology structure of the power distribution network, the technology first determines the key targets in a specific region, and then determines the power supply paths of all reachable target users by using an improved minimum path search method, and further identifies the power distribution key equipment, such as line switches, that may be subjected to network attacks on the paths. In order to make the attack more covert, the attacker will deliberately control the scope of influence outside the key targets to avoid causing large-scale power outages. Therefore, the technology uses an iterative optimization algorithm to determine the actions of the power distribution line switches to simulate the power outage scheme of the attacker implementing network attacks on the regional power distribution network; including the following processes:

[0032] 1. Data preprocessing:

[0033] 1) Use the data provided by the user to extract the busbars separately and form a new table to improve the calculation speed;

[0034] 2) Combine CID and OID to form a unique representation of the device (CID represents the device type, such as 101 for bus and 114 for switch; OID is the serial number, but OID is not unique. Only CID + OID can form a unique data representation).

[0035] 3) Since ATSs appear in pairs, the state of the two switches is generally one open and one closed and they will not be closed at the same time. Therefore, the open and closed state of this type of switch in the data table is written as (0, 1); the normally open switch is a special type of switch that controls the transfer of power. It can achieve the transfer of power for special users. It is generally in the open state. In the data table, it is set to the normally closed state and written as 1.

[0036] 4) Input all important target users within the target area selected by the user.

[0037] 2. Minimum path search within the selected area of ​​the distribution network:

[0038] After data processing, a path table for all important users within the target area is generated based on the least path algorithm. The specific steps are as follows:

[0039] 1) Determine the starting node and the target node, where the target node is all possible feeder start-end circuit breakers;

[0040] 2) Initialize the algorithm by setting the distance of the starting node to 0, setting the distance of all other nodes to infinity (or a large value), and marking the starting node as visited;

[0041] 3) For all nodes adjacent to the starting node, update their distance values ​​(distance to the starting node);

[0042] 4) Among all unvisited nodes, select the node with the smallest distance as the next node to be visited, and mark it as visited;

[0043] 5) For all unvisited nodes adjacent to this node, update their distance values ​​(distance to the starting node);

[0044] 6) Repeat steps four and five until the target node is marked as visited or all nodes have been visited;

[0045] 7) For a distribution network structure with multiple transfer paths, set the states of paired ATSs to (0, 1) and (1, 0) respectively, and keep the open switch in the closed state to perform minimum path search.

[0046] 8) Since each feeder forms an independent loop and possible power supply paths that are not the shortest path will be ignored, the switches on each path should be set to 0 and the shortest path should be searched again. This step should be repeated until no new path can be found.

[0047] 9) Determine whether all important users in the target area have been traversed, if not, return to the first step to recalculate the initial node as an important user not traversed;

[0048] 10) Obtain the minimum power supply path of all reachable key target users in the selected area and form a minimum path set as output.

[0049] 3. Output the additional loss minimum scheme (first scheme):

[0050] According to the formed path set, find the optimal network attack reachable distribution line switch to form a data set. First, check whether there is a network attack target switch upstream of other network attack target switches according to the upstream and downstream relationship. If there is, delete all network attack target switches downstream of the switch. Then check whether there is another switch that can replace the existing switch combination to simplify the switch and form the final output as the output additional loss minimum scheme.

[0051] 4. Output the minimum number of attack switch scheme (second scheme):

[0052] According to the iterative optimization algorithm, find the minimum number of switch scheme, the specific steps are as follows:

[0053] 1) Take the switch obtained in the additional loss minimum scheme as the target switch, and sort these distribution line switches according to their importance. The importance of network attack reachable distribution line switches is mainly affected by their location, user selection area, etc. The core idea is to sort these switches according to the frequency of their appearance in the path obtained by the minimum path algorithm (the higher the frequency, the higher the importance);

[0054] 2) Select the optimal network attack reachable distribution line switch according to the importance sorting and the switch position in the feeder;

[0055] 3) Then evaluate the target area power loss, determine whether the target area has cut off all power supply paths, if so, achieve the expected goal, then provide the current all target switches as output to the user, if not, return to the first step and continue the loop.

[0056] 5. Output the optimal scheme of distribution network key equipment identification:

[0057] Through the comparison of the first two schemes, provide the third optimal scheme to the user, the specific steps are as follows:

[0058] 1) Calculate the additional additional loss caused by the minimum number of output target switches;

[0059] 2) Compare with the solution that minimizes additional output loss. If the additional loss is more than twice that of the target, the solution with the minimum additional loss is taken as the optimal solution. Otherwise, the solution with the fewest attack switches is taken as the output.

[0060] The present invention provides a key equipment identification technology for power distribution networks against regional network attacks, which further includes the following:

[0061] 1. Distribution network topology model:

[0062] In graph theory, a graph G is usually represented by (V(G), D(G)), where V(G) represents a non-empty finite set of the nodes of the graph, and D(G) represents a non-empty finite set of the edges of the graph. In a more concrete description, V(G) = {v1, v2, ..., v} represents the set of nodes in the graph, D(G) represents the set of edges, and an edge d ∈ D(G) represents a pair of nodes {v1, v2, ..., v}. i The connection relationship between v and . If v i If v is connected to v by an edge d, then v is called v i v is the endpoint of this edge.

[0063] like Figure 1 As shown, small black dots are typically used to represent nodes, and line segments between the dots represent edges. If the two endpoints of an edge coincide, the edge is called a cycle; if the endpoints of two edges are the same pair of nodes, these two edges are called multiple edges. A graph containing cycles or multiple edges is called a complex graph.

[0064] For a graph G, if it contains N nodes and M edges, it can be represented by an N×N adjacency matrix, denoted as A = [A...]. i ],in:

[0065]

[0066] In an undirected, unweighted complex network model, the edges in the network have no direction, and each edge has a weight of 1, meaning there is no difference between them. That is, the edge d connecting node i and node j... i ={v i v} is equivalent to d i ={v,v i}, disregarding the directionality between node pairs. The expression for the adjacency matrix A is as follows:

[0067]

[0068] In the distribution network, transfer switch is an important device to realize flexible load transfer. In the topology modeling of distribution network, the state of transfer switch has a direct impact on the representation of adjacency matrix A. When the switch is in the open state (i.e. disconnected), it indicates that the related nodes are no longer connected. In order to reflect this state in the adjacency matrix, the elements corresponding to the row and column of the switch can be set to zero. That is, if the node vi or vj connected by the switch Sij is disconnected, the row and column related to the node vi or vj in the adjacency matrix A are all set to zero.

[0069] 2. A method for identifying key devices in a distribution network under deliberate cyber attack:

[0070] 2.1 Identification of distribution network wiring mode:

[0071] When identifying the devices in the distribution network, the network topology structure needs to be considered to ensure the accuracy of the identification. Therefore, the typical distribution network topology structure needs to be analyzed to ensure the universality of the design scheme. The typical distribution network topology structure mainly includes: basic radial distribution network, radial contact distribution network, always-on loop distribution network and always-closed loop distribution network. For these four kinds of distribution network topology structures, it needs to be considered whether the minimum path method can find all the power supply paths of all key target users in the selected area.

[0072] The radial distribution network transmits electrical energy from the substation to the load branch in a radial manner through the distribution line. Each line supplies power independently, and there is no electrical connection between the lines. It is suitable for areas with low load density, such as rural power grids or small load areas. For the radial distribution network, the minimum path method can effectively search all possible power supply paths from the power source to each load point. Since the radial distribution network structure is relatively simple, there is generally only one power supply path to the important target. When the minimum path method is used for path search, it can ensure that all reachable power supply paths of the important target are accurately found.

[0073] The radial contact distribution network is based on the radial distribution network and adds a contact line. Two or more main feeders from the same substation are connected through always-on switches. Under the premise that the substation does not fail, the two feeders are mutually reserved, which improves the power supply reliability compared with the radial distribution network. When the main line fails, power supply can be restored through the contact line. Under this structure, the important target generally has multiple power supply paths, and the possible all substation front breakers need to be searched as the target of the minimum path method.

[0074] Similar to the radial with tie-in topology, the open-loop radial topology connects two main feeders from the same substation through a tie-in switch. The difference is that the divergent lines in the radial with tie-in topology are only isolated by fuses, while the divergent lines in the open-loop radial topology are equipped with sectionalizing switches. The lines are arranged in a looped layout, usually operating in an open-loop state to avoid forming a closed loop. Each loop has multiple switches, and the open-loop points are usually located at low or intermediate load positions, suitable for areas with high load density and high reliability requirements, such as large industrial areas or urban power grids. For such a topology, the minimum path method search also needs to target all possible substation front breakers. In addition, it should be noted that a single feeder may form a loop and operate in an open-loop state. In this case, only using the basic minimum path method for search may cause a possible power supply path to be ignored, so some switches need to be set to zero to find this possible power supply path.

[0075] The closed-loop radial topology maintains a closed state during normal operation, with power supply and load points connected through multiple paths. This structure is used to improve current distribution within the distribution network, reduce voltage drop and power loss, and is suitable for highly concentrated load areas or places with extremely high requirements for power supply continuity, such as important industrial bases, large urban centers, or critical infrastructure areas. The power supply reliability for key targets is very high, and any single line failure will not cause the load to be powered off. It is similar to the open-loop radial minimum path search method, but due to the reduction of open-loop switches, this topology requires more attack targets.

[0076] ATS (Automatic Transfer Switch) is a device used for automatic switching of power supply, its main function is to switch the load circuit from one power supply side to another, to ensure the continuity and reliability of power supply. In the power system, ATS monitors the power supply status in real time through the built-in control logic, when the main power supply fails (such as power failure, undervoltage or overvoltage), it can quickly trigger the standby power supply or route, and automatically switch the load to the standby power supply or route for power supply; when the main power supply returns to normal, ATS will switch the load back to the main power supply according to the preset logic, and close the standby generator, restoring the normal operation of the system.

[0077] For urban distribution networks with multiple power sources and frequent transfer, the distribution network structure is generally not a simple radial topology, which will make the power supply mode of key target users often diverse and complex. Multiple power sources refer to multiple upper nodes supplying power to users, and multiple transfer paths refer to multiple ATS (Automatic Transfer Switch) and open / close transfer switches in the distribution network. Therefore, in this case, the minimum path method needs to be improved and used to find all the paths for power supply.

[0078] 2.2 Identification of regional distribution network user power supply paths based on improved minimum path method:

[0079] The minimum path search algorithm is a graph-based search algorithm mainly used for finding the optimal power supply path between the power supply point and the load point in the power distribution network. The algorithm first determines the network structure through topological analysis, uses the adjacency matrix or other graph representation methods, and gradually searches all possible paths from the power supply node to the target load node, and selects the path that does not contain redundant devices and meets the power supply conditions as the minimum path. The devices on the minimum path play a decisive role in the reliability of the load point, and their failure will directly lead to the interruption of power supply to the load point; and the elements on the non-minimum path indirectly affect the reliability according to their degree of association with the minimum path.

[0080] The present application mainly considers the influence of the normally open switch and the ATS on the identification of key devices in the power distribution network. In the power distribution network with normally open switches and ATS (automatic transfer switch), the improvement of the minimum path mainly reflects that accurate search can still be achieved when the transfer switch switches and the standby path is introduced. When the main path fails, the transfer switch can quickly switch to the standby path, thereby maintaining the power supply of the load point, at which time the standby path becomes the new minimum path. Therefore, when calculating the minimum path, the standby path after transfer needs to be included in the model to improve the applicability of the algorithm to complex networks. In addition, the introduction of the standby path with ATS makes the search process of the minimum path more complex. If the power supply capacity of the standby path can meet the demand of the load point, the standby path can completely replace the main path, thereby significantly reducing the outage time of the load point; if the capacity is insufficient, the load point needs to be prioritized to ensure that the key load obtains power supply in priority. By integrating the characteristics of the transfer switch and the standby path into the minimum path algorithm, the actual operation of the network can be more comprehensively reflected, thereby improving the accuracy of the power supply reliability evaluation.

[0081] The incidence matrix method is a network topology-based analysis method mainly used for systematically solving all the minimum paths between the input nodes and the output nodes. This method can fully explore all possible paths between nodes in the network by calculating the power of the incidence matrix, and is especially suitable for the analysis of complex network structures and the identification of key paths.

[0082] Assuming that there are n nodes in the network, the incidence matrix A = [A ij ] is an n x n matrix, and the elements A ij are defined as follows: ① If there is a direct connection between node i and node j (i.e., there is an edge), then A ij = 1; ② If there is no direct connection between node i and node j, then A ij = 0. In order to find the minimum path set of longer paths, the incidence matrix A needs to be powered. Ar = [A ij (r)], where A ij(r) represents the number of all paths from node i to node j with path length r. The calculation formula is:

[0083]

[0084] Where “·” represents the multiplication operation of the matrix.

[0085] By calculating the matrix A r , the increase of the matrix power can intuitively represent the change of the path length between nodes. For example, the matrix A represents the path with length 1; the matrix A 2 represents the path with length 2; the matrix A 3 represents the path with length 3, and so on. By performing multiple power operations on the connection matrix, the connectivity of different path lengths can be systematically analyzed. In this process, by selecting the matrix with the smallest power r, all the shortest paths from the target user to the power supply point can be effectively extracted, thereby realizing path optimization and analysis.

[0086] In summary, for the minimum path search of the key equipment identification of the regional distribution network, first, all the associated feeders of the target region are modeled as an undirected graph; second, all the key users in the target region are taken as initial nodes, and the circuit breakers of all the distribution transformers on the feeder and the tie feeder are taken as targets; then, according to different network structures and tie switch types, the minimum path algorithm is used to search from the initial node to the target, and finally, all the minimum paths that can supply power to the important users in the target region are obtained, and a minimum path table is formed.

[0087] 2.3 Iterative optimization algorithm principle:

[0088] In the process of minimizing the additional loss and minimizing the number of attack switches, the key equipment identification scheme of the distribution network aims to determine the optimal solution that disables all important users in the selected region. This algorithm uses a step-by-step iteration approach to approximate the optimal solution, and adjusts according to the state of the current solution in each iteration, thereby continuously optimizing the quality of the solution.

[0089] The iterative optimization algorithm usually starts from an initial solution. In this scheme, the initial solution is obtained by sorting and screening the importance of the network attack accessible distribution line switches on the power supply path. Then, the algorithm gradually optimizes the quality of the solution by repeating specific steps. In each iteration, a possibly better solution is generated using the information of the current solution, until the stopping condition is met, such as reaching the maximum number of iterations or the improvement amplitude of the solution being lower than the preset threshold.

[0090] In scenarios where distribution networks face regional network attacks, attackers can selectively manipulate line switches within a region to launch attacks, thereby achieving precise power outages for all key target users within the region. To address this problem, this solution first selects the target region and identifies all key target users within it. Then, based on an improved minimum path search, it determines the power supply paths for all distribution transformers and their users within the region. Next, it sorts the distribution line switches reachable by the network attack along the power supply paths according to their importance. Finally, an iterative optimization algorithm determines the actions of the line switches, outputting a planned power outage scheme for the distribution network area. Through iterative optimization, this solution can effectively identify critical equipment in the distribution network, providing a scientific basis and technical support for improving network security protection capabilities and power supply reliability.

[0091] The specific process for selecting the optimal disability plan for important users within a region based on iterative optimization algorithms is as follows:

[0092] 1. Optimal selection of the solution with minimum additional loss:

[0093] The goal of this scheme is to find the solution that minimizes the additional loss (Ladd) by adjusting the combination of network attack target switches. Its implementation mainly involves the following steps:

[0094] 1) Finding the device combination with the least additional loss: From the attacker's perspective, based on the principle of least path, find all the device combinations S that are closest to the target load and can be attacked by the network;

[0095] 2) Rapid Determination of Upstream and Downstream Relationships: Based on the aforementioned equipment combination S, and according to the upstream and downstream relationships in the topology, redundant switch combinations are quickly deleted and replaced, reducing the number of switches that need to be calculated. For example, if switch S... i Located in S j Upstream, it can be controlled by S i Disconnection of indirect control S j Then delete S j and its downstream switches to reduce redundant combinations, S′=S / {s j |s j Located in s i Downstream};

[0096] 3) Simplification of switch combinations: Path search prioritizes switches that cover more paths, i.e., determining if fewer switches can replace the existing combination without causing additional load loss. For example, if a certain switch S... c Alternative combinations {S a S b}, then update to: S″=S′ / {s a s b}∪{s c};

[0097] 4) Additional loss calculation: Based on the additional loss contribution value ΔP of each switch. i Prioritize selecting switch combinations with smaller additional loss (Ladd). The calculation formula is as follows:

[0098]

[0099] 2. Optimal selection of the scheme with the fewest attack switches:

[0100] The goal of this scheme is to further optimize based on the scheme with the minimum additional loss, thereby finding the attack switch |S min The solution with the fewest components. Its implementation mainly consists of the following steps:

[0101] 1) Switch Importance Ranking: The iterative optimization algorithm prioritizes switches with the greatest impact on a path by calculating the frequency of each attack-reachable switch in the path. It also evaluates whether the current combination can cut off all power supply paths. If the current combination S... k If it is possible to cut off all power supply paths to the target area without a simpler switch combination, then S min =S k ;

[0102] 2) Iterative optimization: If the target is not achieved, the switches are reordered and the next set of switches is selected to continue optimization.

[0103] 3) Additional loss calculation: Based on the current additional loss contribution value ΔP of each switch. i Calculate the current additional loss L′ add The calculation formula is:

[0104]

[0105] 3. Optimal selection of solutions for identifying key equipment in the distribution network

[0106] This scheme aims to comprehensively consider two strategies: minimizing additional losses and minimizing the number of attack switches. It balances these two strategies and ultimately outputs the optimal solution S for identifying critical equipment in the distribution network. final In the specific implementation process, by setting a maximum allowable value for load loss, Scheme 1 (minimizing additional losses) and Scheme 2 (minimizing the number of attack switches) are optimized. For example, when the maximum allowable value is set to 2, the additional loss L′ of the scheme with the minimum number of attack switches is... add If the number of attacks exceeds twice that of the solution with the minimum additional loss, then the solution with the lower additional loss (Solution 1) is selected first; otherwise, the solution with fewer attack switches (Solution 2) is selected. This constraint-based optimization mechanism enables global optimization of the critical equipment identification scheme while ensuring system reliability.

[0107]

[0108] Iterative optimization algorithms are used throughout the entire process of path search, scheme optimization, and result comparison, and are a key tool for solving complex power distribution network optimization problems.

[0109] When the power supply path of an important target has an ATS or normally open switch to transfer it to a backup power source, this invention can accurately locate these backup paths; it can minimize the number of switches to be struck while ensuring that all power supply paths are cut off to disable the important target.

[0110] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0111] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0112] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for identifying key equipment in a distribution network in response to regional network attacks, characterized in that, Includes the following steps: Based on the distribution network topology model, the distribution network wiring mode is identified and the power supply path of regional distribution network users is obtained. Based on the power supply path, the optimal distribution line switches reachable by network attacks are obtained to form a dataset, forming a first scheme with the minimum additional output loss, and a second scheme with the minimum number of switches is found according to the iterative optimization algorithm. Identify key equipment in the power distribution network according to the first or second scheme; When obtaining the first solution, check whether there is a network attack target switch upstream of other network attack target switches based on the upstream and downstream relationship. If so, delete all network attack target switches downstream of that switch. Then check whether there are other switches that can replace the existing switch combination to simplify the switch and form the first solution. When obtaining the second solution, the switches obtained from the solution with the minimum additional loss are used as target switches and ranked by importance. The optimal distribution line switch reachable by the network attack is selected according to the importance ranking and the position information of the switch on the feeder. The power loss situation in the target area is evaluated to determine whether all power supply paths in the target area have been cut off. If the expected goal is achieved, all current target switches are provided to the user as output. If the expected goal is not achieved, the process returns and continues to loop to obtain the second solution with the fewest switches.

2. The method for identifying key equipment in a distribution network against regional network attacks according to claim 1, characterized in that: In the process of obtaining the distribution network topology model, the distribution network topology modeling is carried out based on the study of complex network theory.

3. The method for identifying key equipment in a distribution network against regional network attacks according to claim 2, characterized in that: When obtaining the power supply path for users in the regional distribution network, all associated feeders in the target area are modeled as an undirected graph. All key users in the target area are taken as initial nodes, and the circuit breakers of all distribution transformers above the feeders where the users are located and the tie feeders are taken as targets. According to different network structures and tie switch types, the minimum path algorithm is used to search from the initial nodes to the targets to obtain all possible minimum paths to supply power to important users in the target area, and a minimum path table is formed as the power supply path for the users in the regional distribution network.

4. The method for identifying key equipment in a distribution network against regional network attacks according to claim 1, characterized in that: When using the iterative optimization algorithm, the initial solution is obtained by sorting the importance of the power distribution line switches that can be reached by network attacks on the power supply path and then filtering them. The quality of the initial solution is then gradually optimized by repeating specific steps through the iterative optimization algorithm. In each iteration, a potentially better solution is generated using information from the current solution, until the stopping condition is met.

5. The method for identifying key equipment in a distribution network against regional network attacks according to claim 1, characterized in that: When identifying key equipment in the distribution network, the additional losses caused by the second scheme are compared with those caused by the first scheme. If the additional losses are greater than twice the target, the scheme with the minimum additional losses is taken as the optimal scheme; otherwise, the scheme with the minimum number of attack switches is taken as the output. The key equipment in the distribution network is identified based on the output results.

6. A distribution network key equipment identification system for regional network attacks, used to implement the distribution network key equipment identification method for regional network attacks as described in claim 1, characterized in that, include: The path planning module is used to identify the wiring pattern of the distribution network and obtain the power supply path for users in the regional distribution network based on the distribution network topology model. The scheme acquisition module is used to acquire the optimal distribution line switches reachable by network attacks based on the power supply path to form a dataset, form a first scheme with the minimum additional output loss, and find a second scheme with the minimum number of switches based on an iterative optimization algorithm. The identification module is used to identify key equipment in the distribution network according to the first scheme or the second scheme.

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