Power distribution network fault repairing method and system based on information physical system

Abstract

The invention discloses a power distribution network fault repairing method and system based on an information physical system. The method comprises the following steps: acquiring basic parameters of a power layer and a communication layer in a power distribution network; constructing a double-layer optimization concurrent fault recovery model according to the basic parameters; the upper layer of the double-layer optimization concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimization concurrent fault recovery model is a power layer fault recovery model; solving the communication layer fault recovery model to obtain a recovery link of the communication layer, reconstructing the power layer fault recovery model based on the recovery link to obtain a power layer fault recovery reconstruction model, and solving the power layer fault recovery reconstruction model to obtain a fault recovery scheme to control the power distribution network to be repaired; a collaborative recovery model with recovery of a communication layer prior to a physical layer as a strategy is constructed based on the CPS, ordered recovery of the power distribution network during CPS concurrent faults is realized, and the fault recovery efficiency of the power distribution network is also greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network fault repair, and in particular to a distribution network fault repair method and system based on an information-physical system. Background Art

[0002] The significant progress of the power grid has attracted the industry's attention to the concept of Cyber-Physical Systems (CPS). Due to natural disasters and human malicious behavior, the communication layer and power layer in the distribution network often fail at the same time. CPS integrates computing, communication and physical processes and is often used for fault repair in distribution networks. However, it usually starts with hardware failures, then repairs physical link failures and network configuration and protocol failures. Finally, it locates the distribution network from user-side PCs to access switches, from access switches to aggregation layer switches, and from aggregation layer switches to core switches in sections and takes corresponding repair measures. However, this repair solution involves multiple levels and components, that is, repairing the physical layer first and then the communication layer. It takes a long time and requires certain technical knowledge and experience during repair. The technical threshold is high, resulting in limited repair personnel, so the efficiency of fault repair is low.

[0003] It can be seen that how to improve the fault repair efficiency of the distribution network has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0004] The present invention provides a distribution network fault repair method and system based on a cyber-physical system, which solves the problem of how to improve the fault repair efficiency of the distribution network.

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a distribution network fault repair method based on a cyber-physical system, comprising: Obtain basic parameters of the power layer and communication layer in the distribution network; A double-layer optimized concurrent fault recovery model is constructed according to the basic parameters; the upper layer of the double-layer optimized concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimized concurrent fault recovery model is a power layer fault recovery model; By solving the communication layer fault recovery model, the recovery link of the communication layer is obtained, and the power layer fault recovery model is reconstructed based on the recovery link, and the power layer fault recovery reconstruction model is obtained and solved, and a fault repair plan is obtained to control the distribution network for repair.

[0006] As one of the preferred schemes, the basic parameters of the power layer include the topological structure data of the power layer, the number of power nodes, and the location distribution data of power sources, switches, circuit breakers and loads; the basic parameters of the communication layer include the topological structure data of the communication layer, the number of communication nodes, network transmission delay parameters, and the location distribution data of measurement devices, routers and central processing units.

[0007] As one of the preferred solutions, the building of a two-layer optimized concurrent fault recovery model according to the basic parameters includes: Based on the basic parameters, the communication layer fault recovery model is constructed with the link capacity, link connectivity and service integrity of the communication layer as the first constraint condition, and with the minimum recovery delay of the communication layer and the minimum consumption of resources required for recovery as the first goal; Based on the basic parameters, the power layer fault recovery model is constructed with the power layer power flow constraint and topology reset as the second constraint condition, and the power layer network loss is minimized, the number of switch operations is minimized, and the voltage deviation is minimized as the second goal; The communication layer fault recovery model and the power layer fault recovery model are combined to obtain the dual-layer optimized concurrent fault recovery model.

[0008] As one of the preferred solutions, the communication layer fault recovery model is expressed by the following formula: In the formula, f c As the first goal; is the switch state of the communication link between node i and node j in the communication layer; is the number of communication nodes in the communication layer; The communication layer is the delay of the communication link ij; For the business flow in the communication layer The occupancy status of the transmission link to the communication link ij; r ij The recovery resources consumed to repair the failed communication link ij; is the weight coefficient.

[0009] As one preferred solution, the first constraint condition includes: Connectivity constraints are expressed as follows: In the formula, is the fault state of the communication link ij in the communication layer; The upstream node i of the communication link in the communication layer has no failure; The downstream node j of the communication link in the communication layer has no failure; is the set of all available communication links in the communication layer; G is the connection constraint from the communication terminal to the master station in the communication layer; The link capacity constraint is expressed as follows: In the formula, For business flow gather; Transmitting service flow for the communication layer The bandwidth required; is the failure capacity of the communication link ij after the communication layer fails; is the original capacity of the communication link ij in the communication layer; The business integrity constraint is expressed as follows: Where E is the service flow completed by the communication layer The required set of communication nodes; For business flow The source node of For business flow The target node.

[0010] As one of the preferred solutions, the power layer fault recovery model is expressed by the following formula: In the formula, f p For the second goal; x p is the state of each switch in the power layer; is the network loss of branch i in the power layer; nl is the number of power lines in the power layer; Y k , Z j are the states of the segment switches and loop switches after the power layer is reconstructed; m and n are the numbers of segment switches and loop switches in the power layer; V m , V0 are the voltage and reference voltage of power node m in the power layer respectively; nb is the number of power nodes in the power layer; α, β and γ are the weight of network loss, switch operation frequency and voltage deviation in the power layer respectively.

[0011] As one preferred solution, the second constraint condition includes: The power flow constraint is expressed as follows: Where P ij , Q ij are respectively the active power and reactive power of the branch from node i to node j in the power layer;i is the voltage of node i in the power layer; is the norm of the matrix; The topology reset constraint is expressed as follows: Where N is the total number of nodes in the power layer after topology reconfiguration; S ij 、F i are the outflow and inflow of node i in the power layer after topology reconfiguration; S ki is the apparent power of the branch from node k to node i in the power grid; M is a parameter.

[0012] As one of the preferred solutions, the communication layer fault recovery model is solved to obtain a recovery link of the communication layer, the power layer fault recovery model is reconstructed based on the recovery link, a power layer fault recovery reconstruction model is obtained and solved, and a fault repair plan is obtained to control the distribution network for repair, including: Solving the communication layer fault recovery model through a dynamic routing algorithm to obtain a recovery link for the communication layer, and based on the recovery link, converting and reconstructing the communication layer fault recovery model into the power layer fault recovery reconstruction model; According to the recovery link, a power communication coupling constraint is constructed, and based on the power communication coupling constraint, the power layer fault recovery reconstruction model is solved by a second-order cone relaxation reconstruction algorithm to obtain configuration topology information and configuration operation parameters and control the distribution network execution for repair; the power communication coupling constraint is used to characterize the controllability of the communication layer over the power layer.

[0013] As one of the preferred solutions, the power communication coupling constraint is expressed by the following formula: In the formula, It is the power communication coupling constraint; Reconstructing the enable signals of each switch in the model for power layer fault recovery; The status of each link after the distribution network is repaired; is the delay of the corresponding link.

[0014] A second aspect of the present invention provides a distribution network fault repair system based on a cyber-physical system, comprising: Data acquisition module, used to obtain basic parameters of the power layer and communication layer in the distribution network; A model building module, used to build a double-layer optimized concurrent fault recovery model according to the basic parameters; the upper layer of the double-layer optimized concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimized concurrent fault recovery model is a power layer fault recovery model; The model solving module is used to obtain the recovery link of the communication layer by solving the communication layer fault recovery model, so as to reconstruct the power layer fault recovery model based on the recovery link, obtain the power layer fault recovery reconstruction model and solve it, and obtain the fault repair plan to control the distribution network for repair.

[0015] Compared with the prior art, the embodiments of the present invention have the following advantages: (1) By obtaining the basic parameters of the power layer and communication layer in the distribution network, accurate data support is provided for the construction of a two-layer optimization model. The two-layer optimization model can simultaneously consider the fault recovery problems of the communication layer and the power layer, realizing cross-layer collaborative optimization. The upper communication layer fault recovery model is responsible for optimizing the recovery strategy of the communication link, while the lower power layer fault recovery model further optimizes the fault recovery plan of the power network based on the upper layer decision results. (2) After solving the communication layer fault recovery model and obtaining the recovery link, the power layer fault recovery model is solved based on the link to obtain the final fault repair solution. The layered solution method used improves the solution efficiency and reduces the computational complexity. (3) Based on CPS, a collaborative recovery model is constructed with the strategy of restoring the communication layer before the physical layer. This can achieve orderly recovery of the distribution network when CPS fails concurrently, and also greatly improve the efficiency of fault repair of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a flow chart of a distribution network fault repair method based on a cyber-physical system provided by a certain embodiment of the present invention; Figure 2 is a flowchart of step S2 provided by an embodiment of the present invention; Figure 3 is a schematic diagram of a power grid branch structure in a power layer provided by a certain embodiment of the present invention; Figure 4 is a flowchart of step S3 provided by an embodiment of the present invention; Figure 5 is a flow chart of a distribution network fault repair method based on a cyber-physical system provided by another embodiment of the present invention; Figure 6 It is a schematic diagram of upper communication layer structure recovery provided by an embodiment of the present invention; Figure 7 is a schematic diagram of lower power layer structure restoration provided by an embodiment of the present invention; Figure 8 It is a structural diagram of a distribution network fault repair system based on an information-physical system provided by a certain embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of this application, the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0020] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two components. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used herein are for illustrative purposes only, and do not indicate or imply that the system or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0021] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0022] In one embodiment, if Figure 1 As shown, the first aspect of the present invention provides a distribution network fault repair method based on a cyber-physical system, comprising: S1. Obtain basic parameters of the power layer and the communication layer in the distribution network; wherein the basic parameters of the power layer include the topological structure data of the power layer, the number of power nodes, and the location distribution data of power sources, switches, circuit breakers and loads; the basic parameters of the communication layer include the topological structure data of the communication layer, the number of communication nodes, network transmission delay parameters, and the location distribution data of measurement devices, routers and central processors; Specifically, the communication layer in the present invention can also be considered as a communication network system, a power communication system, etc., which mainly involves power communication technology and networks in the distribution network, is responsible for transmitting control signals, status information and data in the distribution network, ensures the normal operation and monitoring of the distribution network, and is the basis for the realization of distribution network automation and smart grid. It usually includes wired communication (such as optical fiber communication, power line carrier communication, etc.) and wireless communication (such as wireless local area network, mobile communication network, etc.); among which, the basic parameters of the communication layer include at least the topological structure of the layer, the number of communication nodes, the network transmission delay parameters, and the measurement devices contained in the layer (devices for measuring bandwidth or other basic data), and the location distribution data of routers and central processing units.

[0023] The power layer in the present invention can also be considered as a power grid system, hardware layer, physical power system, etc., which refers to the power transmission and distribution system in the distribution network, which is the core part of the distribution network, including overhead lines, cables, poles, distribution transformers, switchgear and other physical equipment, which are used to distribute electric energy from the transmission network to end users; among them, the basic parameters of the power layer include at least the topological structure of the layer, the number of power nodes, and the location distribution data of the power sources, switches, circuit breakers and loads contained in the layer.

[0024] S2. constructing a double-layer optimized concurrent fault recovery model according to the basic parameters; the upper layer of the double-layer optimized concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimized concurrent fault recovery model is a power layer fault recovery model; In one embodiment, step S2 is as follows Figure 2 As shown, including: S21. Based on the basic parameters, with the link capacity, link connectivity and service integrity of the communication layer as the first constraint condition, and with the minimum recovery delay of the communication layer and the minimum consumption of resources required for recovery as the first goal, construct the communication layer fault recovery model; Specifically, since the communication quality between the physical equipment of the distribution network and the master station, such as switches and delay rates, has an important impact on its scheduling and operation, the fault recovery of the communication layer is to find the link with the minimum delay time and the minimum resource consumption under the premise of the connectivity of the communication network of the communication layer. Then the fault recovery model of the communication layer is expressed by the following formula: In the formula, f c (x C ) is the objective function of the communication layer fault recovery model; is the switch state of the communication link between node i and node j in the communication layer, and is also the optimization variable of the upper communication layer fault recovery model. This is a binary variable. When , the link is closed. When , the link is open; is the number of communication nodes in the communication layer; The communication layer is the delay of the communication link ij; For the business flow in the communication layer The occupancy status of the transmission link to the communication link ij, , 1 means occupied, 0 means unoccupied; r ij The recovery resources consumed to repair the failed communication link ij; is the weight coefficient; ; The present invention takes the recovery delay and the resource consumption required for recovery as the target, which can prompt the communication layer fault recovery model to give priority to those solutions that can quickly restore communication functions when looking for recovery solutions, and fully consider the effective use and conservation of resources, which helps to reduce the service interruption time caused by communication failures and reduce the operating costs of the communication network, thereby improving user satisfaction and resource utilization efficiency.

[0025] In one embodiment, the first constraint condition includes: connectivity constraint, link capacity constraint and service integrity constraint.

[0026] Since the connectivity of the communication link in the communication layer depends on two aspects: one is the connection of the data link, and the other is whether the nodes on the communication link are available, any failure of the communication link and the node will lead to the failure of the connection constraint. Therefore, the connectivity constraint can be expressed by the following formula: In the formula, is the fault state of the communication link ij in the communication layer; If the upstream node i of the communication link in the communication layer does not fail, then An upstream node i of the communication link in the communication layer fails; If the downstream node j of the communication link in the communication layer does not fail, then A downstream node j of the communication link in the communication layer fails; is the set of all available communication links in the communication layer; G is the connection constraint from the communication terminal to the master station in the communication layer; The present invention uses link connectivity as a constraint condition, which can ensure that after failure recovery, various nodes in the communication network can still maintain connection, thereby achieving information intercommunication and sharing.

[0027] Since the bandwidth used by the business flow must be less than the sum of the link capacity bandwidth after the network failure and the link bandwidth restored after the failure, the link capacity constraint is expressed by the following formula: In the formula, For business flow gather; Transmitting service flow for the communication layer The bandwidth required; is the failure capacity of the communication link ij after the communication layer fails; is the original capacity of the communication link ij in the communication layer; The present invention uses link capacity as a constraint condition to ensure that the transmission capacity of the communication link will not be seriously affected during the fault recovery process, which helps to maintain the stability and reliability of the communication network and ensure the normal transmission of information.

[0028] Business integrity means that the communication layer can continue to provide complete services after failure recovery, and the business starts from the source node and ends at the destination node. The business integrity constraint is expressed as follows: Where E is the service flow completed by the communication layer The required set of communication nodes; For business flow The source node of For business flow The target node; The present invention takes service integrity as a constraint condition, which can ensure that the service logic and data integrity in the communication network will not be destroyed during the fault recovery process, thereby ensuring normal use by users.

[0029] The present invention can enhance the network resilience of the communication layer by constructing a fault recovery model with link capacity, link connectivity and business integrity as constraints, so that when facing a fault, the communication layer can recover quickly and continue to provide services, thereby ensuring business continuity and stability; at the same time, in the process of finding a recovery plan, various factors are comprehensively considered to optimize the network structure of the communication layer and improve the reliability and efficiency of the communication layer; by minimizing the resource consumption required for recovery, the communication layer is prompted to use resources more efficiently during the fault recovery process, so as to reduce the operating cost of the network and improve the overall utilization efficiency of resources.

[0030] S22, based on the basic parameters, taking the power flow constraint and topology reset of the power layer as the second constraint condition, and taking minimizing the network loss of the power layer, minimizing the number of switch operations and minimizing the voltage deviation as the second goal, constructing the power layer fault recovery model; Specifically, since the power layer of the distribution network will cause power loss in certain areas when a fault occurs, if the connectivity of the power grid is guaranteed after the fault is restored, the loss load can be fully restored, provided that the upper power grid provides sufficient capacity. Based on this situation, the present invention sets the minimization of network loss, the minimum number of switch operations and the minimum voltage deviation of the power layer as the objective function when constructing the model, and then the power layer fault recovery model is expressed by the following formula: In the formula, x p is the state of each switch in the power layer, and is also the optimization variable of the lower model; is the network loss of branch i in the power layer; nl is the number of power lines in the power layer; Y k , Z j are the states of the segment switches and loop switches after the power layer is reconstructed; m and n are the numbers of segment switches and loop switches in the power layer; V m , V0 are the voltage and reference voltage of power node m in the power layer respectively; nb is the number of power nodes in the power layer; α, β and γ are the weight of network loss, switch operation frequency and voltage deviation in the power layer respectively; The present invention constructs a power layer fault recovery model with minimizing the network loss, switch operation times and voltage deviation of the power layer as the objective function, which can prompt the model to give priority to those solutions that can reduce network losses and reduce voltage deviations when looking for recovery solutions, and reduce unnecessary switching operations, which helps to reduce the operating cost of the distribution network, improve energy utilization efficiency, help extend the service life of equipment, and improve the stability, reliability and voltage quality of the distribution network and users' electricity satisfaction.

[0031] In one embodiment, the second constraint condition includes: power flow constraint and topology reset constraint.

[0032] Since the tidal current adopts a disturbance model based on second-order cone relaxation, the following is used: Figure 3 Taking a certain power grid branch structure in the power layer as an example, the Ohm's law voltage drop and power balance equation of each node are expressed by the following formula: Where U i , U j are the voltages of nodes i and j in the power layer respectively; Z ij is the conductance from node i to node j; S ij ,I ij are the apparent power and current of the branch from node i to node j respectively; S ki , Z ki and I ki are the apparent power, impedance and current of the branch from node k to node i respectively; s i is the power capacity access in node i; Make , , ,and , it can be deduced as: Where P ij , Q ij are respectively the active power and reactive power of the branch from node i to node j in the power layer; u i is the voltage of node i in the power layer; p i ,q i are the active power and reactive power of the power supply connected to node i in the power layer; r ki 、x ki are resistance and reactance respectively; is the current across nodes i and j.

[0033] For quadratic nonlinear equations, the standard second-order cone form of the inequality constraint is obtained by relaxing the second-order cone theorem, then the power flow constraint is expressed as follows: In the formula, is the norm of the matrix; the present invention uses the flow constraint as the constraint condition of the power layer fault recovery model, which can ensure that the power layer flow distribution is reasonable during the fault recovery process, avoiding equipment damage or system collapse caused by flow overload.

[0034] The topology reset constraint can also be considered as a topology reconfiguration constraint. After the service is restored, the radial topology should be guaranteed in the distribution network. Therefore, the topology reset constraint is provided by the virtual flow method, which includes the topology tree decoupling constraint of the distribution network to ensure the connectivity of the distribution network, the KCL constraint on the virtual flow, and the large M method constraint, which is expressed by the following formula: Where N is the total number of nodes in the power layer after topology reconfiguration; S ij 、F i are the outflow and inflow of node i in the power layer after the topology is reconfigured; M is a parameter, which is a relatively large value; if the branch is interrupted, then x ij is equal to 0, and when the branch is connected, x ij is equal to 1, both cases can satisfy the constraints.

[0035] The present invention uses topology reset as a constraint condition, which can ensure that the topology structure of the power layer is reasonable during the recovery process, thereby avoiding operation problems caused by unreasonable topology structure.

[0036] The present invention can enhance the network resilience of the power layer by constructing a power layer fault recovery model with flow constraints and topology reset as constraints, and with the goals of minimizing network losses, minimizing the number of switch operations and minimizing voltage deviations. In the process of finding a recovery plan, the model will comprehensively consider various factors, which will help optimize the network structure of the power layer, improve the reliability and flexibility of the power layer, and enable the power layer to use resources more efficiently during fault recovery, so as to reduce the operating cost of the power system and improve the overall utilization efficiency of resources.

[0037] S23, combining the communication layer fault recovery model and the power layer fault recovery model to obtain the dual-layer optimized concurrent fault recovery model; The present invention uses link capacity, connectivity, and service integrity constraints as constraints, and takes the communication link with the minimum recovery delay and the minimum required resource consumption as the objective function to construct a communication layer fault recovery model, and uses flow constraints and topology reset as constraints, and sets the network loss minimization, the number of switch operations, and the voltage deviation as the objective function to construct a power layer fault recovery model, so that each layer of the model has its own goals and constraints, and the combined two-layer optimization model can simultaneously consider the fault recovery problems of the communication layer and the power layer, and can significantly improve the overall recovery efficiency by coordinating the optimization targets of the two-layer models; comprehensively considering multiple factors such as recovery delay, resource consumption, network loss, and the number of switch operations, the two-layer optimization model can further optimize resource allocation and reduce operating costs on the basis of ensuring safe and stable operation of the system.

[0038] S3, by solving the communication layer fault recovery model, obtaining the recovery link of the communication layer, reconstructing the power layer fault recovery model based on the recovery link, obtaining the power layer fault recovery reconstruction model and solving it, and obtaining a fault repair plan to control the distribution network for repair; In one embodiment, step S3 is as follows Figure 4 As shown, including: S31, solving the communication layer fault recovery model by a dynamic routing algorithm to obtain a recovery link of the communication layer, and based on the recovery link, converting and reconstructing the communication layer fault recovery model into the power layer fault recovery reconstruction model; Specifically, the present invention first configures the parameters required by the Dijkstra algorithm, such as weights (based on factors such as delay, bandwidth, reliability, etc.), number of iterations, convergence conditions, etc., then inputs the fault information into the algorithm, updates the status information of the communication layer (i.e., link status, node status, etc.), and executes a dynamic routing algorithm to search for all possible paths from the source node to the destination node; based on the first constraint condition and the first goal, evaluates the feasibility (whether it meets the requirements of link capacity, connectivity, etc.) and pros and cons (such as recovery delay, resource consumption, etc.) of each path, and selects the optimal path as the recovery link; verifies whether the selected recovery link can indeed restore the service integrity of the communication layer, and when all constraints are met, allocates necessary resources (such as bandwidth, relay equipment, etc.) to the selected recovery link, and updates the configuration information of the communication layer, including the routing table, link status table, etc., to reflect the addition of the recovery link.

[0039] In addition, the performance of the recovery link (such as latency, packet loss rate, etc.) can also be monitored to ensure that it meets business needs, and the fault situation in the communication layer is continuously detected. Once a new fault is detected, the fault recovery process is immediately triggered, and according to the changes in the network status in the communication layer (such as traffic changes, equipment failures, etc.), the recovery link is dynamically adjusted or the dynamic routing algorithm is re-executed to optimize network performance. It should be noted that when solving the model, the present invention abstracts the communication layer into a graph composed of vertices and branches, and solves the path node set with the minimum objective function as the routing link of the communication layer recovery link.

[0040] When the power layer of the distribution network fails concurrently, the master station of the distribution network will lose monitoring and control of the power grid, which will greatly inhibit the ability of the distribution master station to judge network failures and provide recovery strategies. At the same time, it is also difficult to effectively execute topology reconstruction instructions. Therefore, the present invention proposes a fault recovery method based on double-layer optimization to solve the problem of concurrent failures: based on the recovery link, the communication layer fault recovery model is converted and reconstructed into a power layer fault recovery reconstruction model, that is, the network topology structure of the communication layer after fault recovery is replaced with the lower layer, that is, the power layer model reconstructed by the physical topology, that is, the power layer fault recovery reconstruction model, so as to restore the power supply of the power grid system to the greatest extent.

[0041] S32, constructing a power communication coupling constraint according to the recovery link, and solving the power layer fault recovery reconstruction model through a second-order cone relaxation reconstruction algorithm based on the power communication coupling constraint, obtaining configuration topology information and configuration operation parameters and controlling the distribution network to perform repair; the power communication coupling constraint is used to characterize the controllability of the communication layer over the power layer; Specifically, in a CPS-based distribution network, the collected power layer data needs to be uploaded to the distribution master station through the communication layer for fault reconstruction. When the communication node is normal, the corresponding node in the power layer can be fully understood and controlled; on the contrary, when the communication node is in a faulty state, the corresponding node in the power layer will be out of control. Therefore, based on the recovery link, the power communication coupling constraint of the distribution network can be constructed according to the controllability of the communication layer over the power layer; among them, controllability can be understood as the ability of the communication layer in the distribution network to transmit information in real time and accurately, thereby achieving effective control of the power layer. This control includes remote operation of power equipment, real-time monitoring of the power network status, and timely response to power failures. Then the power communication coupling constraint is expressed by the following formula: In the formula, It is the power communication coupling constraint; It is the enable signal of each switch in the power layer fault recovery and reconstruction model. When its value is equal to 1, it indicates that the corresponding switch is controllable. When its value is equal to 0, it indicates that the corresponding switch is uncontrollable. The status of each link after the distribution network is repaired; is the delay of the corresponding link.

[0042] Furthermore, the objective function of the power layer fault recovery and reconstruction model is expressed by the following formula: In the formula, p(x C ),q(x C ) are the equality constraints and non-equality constraints of the upper communication layer fault recovery model, that is, p(x C ) refers to the equality constraints such as connectivity constraints and service integrity constraints of the upper communication layer fault recovery model, q(x C ) represents the link capacity constraint of the upper communication layer fault recovery model; is the objective function of the fault recovery model of the lower power layer considering the upper communication topology; Represents the recovery strategy of the upper communication layer failure recovery model; , are the equality constraints and non-equality constraints of the fault recovery model of the lower power layer, namely Refers to the topology reconstruction constraints of the underlying power layer fault recovery model, Refers to the power flow constraints of the underlying power layer fault restoration model.

[0043] The present invention converts the nonlinear problem in the power layer fault recovery model into a linear or quadratic problem through a second-order cone relaxation technology, then inputs the topological structure, load, branch impedance and fault location of the power layer of the distribution network, uses the second-order cone relaxation method to process the non-convex optimization problem, maps the original problem into a high-dimensional space, and converts the problem into a linear or quadratic problem in the high-dimensional space for solution, and uses YALMIP, Cplex or MOSEK solvers to solve the converted model, obtains the optimal fault recovery plan, outputs the configuration topology information of the distribution network, including switch status, line connection relationship, etc., and simultaneously outputs configuration operation parameters, such as voltage, current, power, etc., to guide the actual operation and repair work of the distribution network; and controls the distribution network to perform repair, applies the obtained configuration topology information and configuration operation parameters to the distribution network, and controls the distribution network to be repaired according to the optimal fault recovery plan.

[0044] The flowchart of another distribution network fault repair method based on cyber-physical system is as follows: Figure 5As shown, the present invention constructs a collaborative recovery model based on CPS with the strategy of restoring the communication layer before the physical layer, thereby realizing the orderly recovery of the distribution network when CPS fails concurrently, and greatly improving the fault repair efficiency of the distribution network; by solving the communication layer fault recovery model, after obtaining the recovery link, the power layer fault recovery model is solved based on the link to obtain the final fault repair plan. The layered solution method adopted improves the solution efficiency and reduces the computational complexity.

[0045] In one embodiment, the following example is used to illustrate the solution of the present invention. The upper communication layer structure recovery schematic diagram is as follows: Figure 6 As shown in the figure, the dotted line represents the damaged link, the solid line represents the undamaged link, C represents the original capacity of the link, R represents the recovery resources consumed to repair the damaged link, and T represents the transmission delay of the service on the link. Assume that nodes 3 and 5 have service flow transmission, and the service bandwidth is 2, but the recovery resources are limited at this time. Assume that the recovery resources are only 5. According to the service flow recovery maximization constraint and service flow constraint, the recovery links that can be selected at this time are (2, 3), (2, 4), and (5, 6), as shown in the following table: It can be seen from the table that when link (2, 4) is restored, the link service flow can be fully restored. At this time, the node transmission delay constraint is met and the transmission delay is minimized. Therefore, combined with the objective function, the link (2, 4) that can maximize the service recovery and minimize the recovery delay is selected under limited resources.

[0046] The schematic diagram of the lower power layer structure restoration is as follows: Figure 7 As shown in the figure, the communication layer topology corresponds to the power layer topology one by one, that is, when the communication network is normal, the communication layer can observe and measure the power nodes in the power layer and can effectively control the circuit breakers. Assuming that the communication layer has been partially restored and a circuit breaker is installed on each link of the power layer, Figure 7 The circuit breakers on the power lines (1, 9) and (3, 4) cannot be controlled; when a fault occurs in the power layer, the power outage protection is triggered, and the circuit breakers of each line are in the disconnected state. By recovering the communication layer, the dispatch center can detect the faulty nodes 6 and 8, and can control the circuit breakers on the normal lines. Next, the control center issues a decision, with the goal of minimizing network losses, the number of switch operations, and the voltage deviation setting, and the topology of the power layer is reconstructed by closing the circuit breakers to achieve fault recovery. That is, the dispatch center changes the circuit breakers on lines (A, 2), (2, 3), (2, 7), (B, 7), and (7, 9) from the disconnected state to the closed state to achieve load recovery, and at the same time adjusts the generator sets to prevent the frequency from exceeding the limit, thereby achieving the recovery of the power CPS.

[0047] In the embodiment of the present application, based on the problem of how to improve the fault repair efficiency of the distribution network, a distribution network fault repair method based on an information-physical system is designed, which realizes the acquisition of basic parameters of the power layer and the communication layer in the distribution network; constructs a two-layer optimized concurrent fault recovery model according to the basic parameters; the upper layer of the two-layer optimized concurrent fault recovery model is the communication layer fault recovery model, and the lower layer of the two-layer optimized concurrent fault recovery model is the power layer fault recovery model; by solving the communication layer fault recovery model, the recovery link of the communication layer is obtained, and the power layer fault recovery model is reconstructed based on the recovery link, and the power layer fault recovery reconstruction model is obtained and solved, and a fault repair plan is obtained to control the distribution network to repair the technical solution; based on CPS, a collaborative power supply recovery model with the strategy of communication layer recovery before physical layer recovery is constructed, which helps to improve the CPS's ability to cope with extreme natural disasters and the fault repair efficiency of the distribution network.

[0048] It should be noted that although the steps in the above flowchart are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders.

[0049] In another embodiment, if Figure 8 As shown, the second aspect of the present invention provides a distribution network fault repair system based on a cyber-physical system, comprising: The data acquisition module 10 is used to obtain the basic parameters of the power layer and the communication layer in the distribution network; A model building module 20 is used to build a double-layer optimized concurrent fault recovery model according to the basic parameters; the upper layer of the double-layer optimized concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimized concurrent fault recovery model is a power layer fault recovery model; The model solving module 30 is used to obtain the recovery link of the communication layer by solving the communication layer fault recovery model, reconstruct the power layer fault recovery model based on the recovery link, obtain the power layer fault recovery reconstruction model and solve it, and obtain the fault repair plan to control the distribution network for repair.

[0050] It should be noted that each module in the above-mentioned distribution network fault repair system based on information-physical system can be fully or partially implemented by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules. For the specific definition of a distribution network fault repair system based on information-physical system, please refer to the definition of a distribution network fault repair method based on information-physical system above. The two have the same functions and effects, which will not be repeated here.

[0051] In summary, the present invention relates to the field of distribution network fault repair technology, and discloses a distribution network fault repair method and system based on an information-physical system, wherein the method includes obtaining basic parameters of the power layer and the communication layer in the distribution network; constructing a two-layer optimized concurrent fault recovery model according to the basic parameters; the upper layer of the two-layer optimized concurrent fault recovery model is the communication layer fault recovery model, and the lower layer of the two-layer optimized concurrent fault recovery model is the power layer fault recovery model; by solving the communication layer fault recovery model, a recovery link of the communication layer is obtained, and the power layer fault recovery model is reconstructed based on the recovery link, and a power layer fault recovery reconstruction model is obtained and solved, and a fault repair plan is obtained to control the distribution network to be repaired; based on CPS, a collaborative recovery model with the strategy of communication layer recovery before physical layer recovery is constructed, so as to realize orderly recovery of the distribution network when CPS fails concurrently, and also greatly improve the fault repair efficiency of the distribution network.

[0052] Each embodiment in this specification is described in a progressive manner, and the same or similar parts of each embodiment can be directly referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system 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. It should be noted that the technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above-mentioned embodiments only express several preferred implementation modes of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in the technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be based on the protection scope of the claims.

Claims

1. A distribution network fault repair method based on cyber-physical system, characterized in that: include: Obtain basic parameters of the power layer and communication layer in the distribution network; A double-layer optimized concurrent fault recovery model is constructed according to the basic parameters; the upper layer of the double-layer optimized concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimized concurrent fault recovery model is a power layer fault recovery model; By solving the communication layer fault recovery model, the recovery link of the communication layer is obtained, and the power layer fault recovery model is reconstructed based on the recovery link, and the power layer fault recovery reconstruction model is obtained and solved, and a fault repair plan is obtained to control the distribution network for repair.

2. A distribution network fault repair method based on cyber-physical system according to claim 1, characterized in that: The basic parameters of the power layer include the topological structure data of the power layer, the number of power nodes, and the location distribution data of power sources, switches, circuit breakers and loads; the basic parameters of the communication layer include the topological structure data of the communication layer, the number of communication nodes, network transmission delay parameters, and the location distribution data of measurement devices, routers and central processing units.

3. A distribution network fault repair method based on cyber-physical system according to claim 1, characterized in that: The constructing of a two-layer optimized concurrent fault recovery model according to the basic parameters includes: Based on the basic parameters, the communication layer fault recovery model is constructed with the link capacity, link connectivity and service integrity of the communication layer as the first constraint condition, and with the minimum recovery delay of the communication layer and the minimum consumption of resources required for recovery as the first goal; Based on the basic parameters, the power layer fault recovery model is constructed with the power layer power flow constraint and topology reset as the second constraint condition, and the power layer network loss is minimized, the number of switch operations is minimized, and the voltage deviation is minimized as the second goal; The communication layer fault recovery model and the power layer fault recovery model are combined to obtain the dual-layer optimized concurrent fault recovery model.

4. A distribution network fault repair method based on cyber-physical system according to claim 3, characterized in that: The communication layer fault recovery model is expressed by the following formula: In the formula, f c As the first goal; is the switch state of the communication link between node i and node j in the communication layer; is the number of communication nodes in the communication layer; The communication layer is the delay of the communication link ij; For the business flow in the communication layer The occupancy status of the transmission link to the communication link ij; r ij The recovery resources consumed to repair the failed communication link ij; is the weight coefficient.

5. A distribution network fault repair method based on cyber-physical system according to claim 4, characterized in that: The first constraint condition includes: Connectivity constraints are expressed as follows: In the formula, is the fault state of the communication link ij in the communication layer; The upstream node i of the communication link in the communication layer has no failure; The downstream node j of the communication link in the communication layer has no failure; is the set of all available communication links in the communication layer; G is the connection constraint from the communication terminal to the master station in the communication layer; The link capacity constraint is expressed as follows: In the formula, For business flow gather; Transmitting service flow for the communication layer The bandwidth required; is the failure capacity of the communication link ij after the communication layer fails; is the original capacity of the communication link ij in the communication layer; The business integrity constraint is expressed as follows: Where E is the service flow completed by the communication layer The required set of communication nodes; For business flow The source node of For business flow The target node.

6. A distribution network fault repair method based on cyber-physical system according to claim 5, characterized in that: The power layer fault recovery model is expressed by the following formula: In the formula, f p For the second goal; x p is the state of each switch in the power layer; is the network loss of branch i in the power layer; nl is the number of power lines in the power layer; Y k , Z j are the states of the segment switches and loop switches after the power layer is reconstructed; m and n are the numbers of segment switches and loop switches in the power layer; V m , V0 are the voltage and reference voltage of power node m in the power layer respectively; nb is the number of power nodes in the power layer; α, β and γ are the weight of network loss, switch operation frequency and voltage deviation in the power layer respectively.

7. A distribution network fault repair method based on cyber-physical system according to claim 6, characterized in that: The second constraint condition includes: The power flow constraint is expressed as follows: Where P ij , Q ij are respectively the active power and reactive power of the branch from node i to node j in the power layer; i is the voltage of node i in the power layer; is the norm of the matrix; The topology reset constraint is expressed as follows: Where N is the total number of nodes in the power layer after topology reconfiguration; S ij 、F i are the outflow and inflow of node i in the power layer after topology reconfiguration; S ki is the apparent power of the branch from node k to node i in the power grid; M is a parameter.

8. A distribution network fault repair method based on cyber-physical system according to claim 6, characterized in that: The method solves the communication layer fault recovery model to obtain a recovery link of the communication layer, reconstructs the power layer fault recovery model based on the recovery link, obtains and solves the power layer fault recovery reconstruction model, and obtains a fault repair plan to control the distribution network for repair, including: Solving the communication layer fault recovery model through a dynamic routing algorithm to obtain a recovery link for the communication layer, and based on the recovery link, converting and reconstructing the communication layer fault recovery model into the power layer fault recovery reconstruction model; According to the recovery link, a power communication coupling constraint is constructed, and based on the power communication coupling constraint, the power layer fault recovery reconstruction model is solved by a second-order cone relaxation reconstruction algorithm to obtain configuration topology information and configuration operation parameters and control the distribution network execution for repair; the power communication coupling constraint is used to characterize the controllability of the communication layer over the power layer.

9. A distribution network fault repair method based on cyber-physical system according to claim 8, characterized in that: The power communication coupling constraint is expressed by the following formula: In the formula, It is the power communication coupling constraint; Reconstructing the enable signals of each switch in the model for power layer fault recovery; The status of each link after the distribution network is repaired; is the delay of the corresponding link.

10. A distribution network fault repair system based on cyber-physical system, characterized in that: include: Data acquisition module, used to obtain basic parameters of the power layer and communication layer in the distribution network; A model building module, used to build a double-layer optimized concurrent fault recovery model according to the basic parameters; the upper layer of the double-layer optimized concurrent fault recovery model is a communication layer fault recovery model, and the lower layer of the double-layer optimized concurrent fault recovery model is a power layer fault recovery model; The model solving module is used to obtain the recovery link of the communication layer by solving the communication layer fault recovery model, so as to reconstruct the power layer fault recovery model based on the recovery link, obtain the power layer fault recovery reconstruction model and solve it, and obtain the fault repair plan to control the distribution network for repair.

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