Power distribution network information physical system integrated modeling method considering multilayer coupling

Abstract

The invention belongs to the technical field of power system cyber-physical fusion, and discloses a power distribution network cyber-physical system integrated modeling method considering multilayer coupling, comprising the following steps: dividing system levels according to an entity architecture of a power distribution network cyber-physical system, the system levels comprising a physical layer, a cyber-physical coupling layer and an information layer; the method comprises the following steps of: converting an entity architecture of a power distribution network information physical system into a graph theory model by applying a complex network theory framework, and representing system topology and function interaction characteristics by establishing a multi-layer network structure; constructing a physical layer model, an information physical coupling layer model and an information layer model in a layered manner, and describing a coupling relationship and association characteristics among the hierarchical models by using an association matrix; by considering coupling association among multiple levels, the model accurately describes essential characteristics of the multilayer heterogeneous system, and the dynamic regulation and control capability and the operation efficiency of the system are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system cyber-physical integration, and specifically relates to an integrated modeling method for a distribution network cyber-physical system considering multi-layer coupling. Background Art

[0002] Under the background of the coordinated development of the dual transformation of energy and digitalization, the traditional distribution network is transforming into an intelligent cyber-physical system. The deep integration of the control center and the communication network makes it difficult for the existing distribution network models to accurately represent the interaction mechanism between the information domain and the physical domain, restricting the improvement of the system's dynamic regulation ability; at the same time, the large-scale deployment of a large number of heterogeneous intelligent terminal devices makes the distribution network cyber-physical system show significant complexity characteristics in dimensions such as structural topology, state evolution, and functional characteristics, and the traditional power system models can no longer meet the modeling requirements of the new distribution network;

[0003] Although existing research has begun to apply the theory of cyber-physical systems, it is mainly limited to a single-level analysis framework, modeling the information network by refining it into independent units such as the backbone network and the access network, and failing to fully consider the coupling relationship between multiple levels, resulting in the model being difficult to accurately depict the essential characteristics of the multi-layer heterogeneous system. Therefore, it is necessary to study the integrated modeling of the distribution network cyber-physical system. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an integrated modeling method for a distribution network cyber-physical system considering multi-layer coupling.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An integrated modeling method for a distribution network cyber-physical system considering multi-layer coupling includes the following steps:

[0007] According to the entity architecture of the distribution network cyber-physical system, divide the system levels, and the system levels include the physical layer, the cyber-physical coupling layer, and the information layer;

[0008] Using the complex network theory framework, transform the entity architecture of the distribution network cyber-physical system into a graph theory model, and characterize the system topology and functional interaction characteristics by establishing a multi-layer network structure;

[0009] Construct the physical layer model, the cyber-physical coupling layer model, and the information layer model layer by layer, and use the incidence matrix to describe the coupling relationship and correlation characteristics between the models of each layer;

[0010] According to the information transfer process of the distribution network cyber-physical system, establish a closed-loop control mechanism to form an integrated dynamic model of the distribution network cyber-physical system.

[0011] Establish a multi-layer network structure Gg As follows: G g = (V g , E g );

[0012] Among them, V g represents the node set, including physical nodes, secondary equipment nodes and information nodes;

[0013] E g represents the edge set, which is used to describe the connection relationship between each layer.

[0014] Model the entity components in the physical layer of the power distribution network cyber-physical system as physical nodes;

[0015] Model the intelligent terminal devices in the cyber-physical coupling layer of the power distribution network cyber-physical system as secondary equipment nodes;

[0016] Model the control center and information network in the information layer of the power distribution network cyber-physical system as information nodes.

[0017] Build the physical layer model, cyber-physical coupling layer model and information layer model hierarchically, and use the incidence matrix to describe the coupling relationship and correlation characteristics between each layer model. The specific steps are as follows:

[0018] Use the incidence matrix to establish the physical layer state matrix, secondary equipment layer deployment matrix, communication layer transmission matrix and information layer decision matrix;

[0019] The physical layer state matrix describes the state and topological connection relationship of each physical node in the physical layer model through the incidence matrix;

[0020] The secondary equipment layer deployment matrix describes the spatial distribution of secondary equipment nodes in the cyber-physical coupling layer model and their topological connection relationship with physical nodes through the incidence matrix;

[0021] The communication layer transmission matrix describes the information up and down transmission characteristics of the communication network in the cyber-physical coupling layer model. The up transmission uploads the operation state of the physical layer model to the information layer model, and the down transmission sends the control instructions of the information layer model to the physical layer model;

[0022] The information layer decision matrix describes the interaction relationship between the decision-making algorithm of the control center in the information layer model and the physical layer model. The control center generates control instructions according to the operation state of the physical layer model and sends them to the physical layer model through the communication layer transmission matrix.

[0023] The closed-loop control mechanism includes the information layer model monitoring the physical layer model mechanism, the information layer model control center optimization decision mechanism and the physical layer model power network controlled mechanism;

[0024] The information layer model monitors the physical layer model mechanism: The information layer model collects power network status information from the physical layer model through the upstream matrix of the communication network and the secondary device deployment matrix to form an information collection matrix;

[0025] The information layer model control center optimization decision-making mechanism: The control center generates optimization instructions using a decision algorithm based on the collected status information to form an instruction issuance matrix;

[0026] The physical layer model power network controlled mechanism: The optimization instructions are sent to the physical layer model through the downstream matrix of the communication network, and the physical layer model adjusts its operating state according to the instructions to form a controlled matrix;

[0027] The adjusted power network status information is uploaded as a new round of data to form a closed-loop control.

[0028] The expression of the information layer model monitoring the physical layer model mechanism is as follows:

[0029]

[0030] In the formula, C receieve is the information collection matrix of the information layer model; S up is the upstream matrix of the communication network; R is the secondary device deployment matrix; P 0 is the initial power network status matrix of the physical layer model;

[0031] The expression of the information layer model control center optimization decision-making mechanism is as follows:

[0032] C send = G(C receive ) (2)

[0033] In the formula, C send is the instruction issuance matrix of the information layer model; G(·) is the decision algorithm of the information layer model;

[0034] The expression of the physical layer model power network controlled mechanism is as follows:

[0035]

[0036] In the formula, P control is the controlled matrix of the physical layer model after receiving the instructions, S down is the downstream matrix of the communication network; R is the secondary device deployment matrix.

[0037] The entity components include power generation devices, substation equipment, and distributed energy devices;

[0038] The intelligent terminal devices include DTU and FTU.

[0039] The beneficial effects of the present invention:

[0040] 1. The present invention constructs a physical layer model, a cyber-physical coupling layer model, and an information layer model hierarchically, and uses an incidence matrix to achieve multi-level coupling, clearly depicting the information flow transmission and dynamic regulation process. Compared with the single-level modeling method in the prior art, the present invention can more accurately describe the complex interaction mechanism of the distribution network cyber-physical system, providing a theoretical basis for the optimal operation and hierarchical management of the system;

[0041] 2. Through the closed-loop control mechanism, the system can collect the operating state of the physical layer model in real time and dynamically adjust the control instructions according to the decision-making algorithm of the information layer model, significantly improving the response speed and regulation accuracy of the system;

[0042] 3. The present invention introduces the information layer to achieve real-time regulation and decision-making for the distribution network. When a fault occurs, the system can quickly locate the fault point and generate optimization instructions to complete operations such as fault isolation and load transfer, minimizing the power outage probability in the non-fault area and improving the reliability and power supply continuity of the system;

[0043] 4. The present invention is applicable to various operation scenarios such as the optimal operation, hierarchical management, and safety regulation of modern intelligent distribution networks. By comprehensively considering the coupling relationship and correlation characteristics between each layer, the system can flexibly respond to different operation requirements, providing technical support for the intelligent development of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0045] Figure 1 is a schematic diagram of the multi-layer network structure of the present invention;

[0046] Figure 2 is a schematic diagram of the comparative simulation results of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0048] Such as Figures 1 to 2As shown in the figure, an integrated modeling method for a cyber-physical system of a distribution network considering multi-layer coupling includes the following steps:

[0049] According to the entity architecture of the cyber-physical system of the distribution network, divide the system levels, and the system levels include the physical layer, the cyber-physical coupling layer, and the information layer;

[0050] Using the complex network theory framework, transform the entity architecture of the cyber-physical system of the distribution network into a graph theory model, and characterize the system topology and functional interaction characteristics by establishing a multi-layer network structure;

[0051] Build the physical layer model, the cyber-physical coupling layer model, and the information layer model hierarchically, and use the incidence matrix to describe the coupling relationship and correlation characteristics between the models at each level;

[0052] According to the information transfer process of the cyber-physical system of the distribution network, establish a closed-loop control mechanism to form an integrated dynamic model of the cyber-physical system of the distribution network.

[0053] The information flow is the information transfer process of information collection and upload, control center decision-making, and control instruction issuance in the cyber-physical system of the distribution network;

[0054] Establish a multi-layer network structure G g as follows: G g =(V g , E g );

[0055] where V g represents the node set, including physical nodes, secondary equipment nodes, and information nodes;

[0056] E g represents the edge set, which is used to describe the connection relationship between each level.

[0057] Model the entity components in the physical layer of the cyber-physical system of the distribution network as physical nodes;

[0058] Model the intelligent terminal devices in the cyber-physical coupling layer of the cyber-physical system of the distribution network as secondary equipment nodes;

[0059] Model the control center and the information network in the information layer of the cyber-physical system of the distribution network as information nodes.

[0060] Use the incidence matrix to mathematically describe the relationship between nodes and edges, so as to abstractly express the internal mechanism and operation law of multi-level interaction in a complex system through graph theory analysis methods.

[0061] Build the physical layer model, the cyber-physical coupling layer model, and the information layer model hierarchically, and use the incidence matrix to describe the coupling relationship and correlation characteristics between the models at each level. Specifically, it includes the following steps:

[0062] Establish a physical layer status matrix, a secondary equipment layer deployment matrix, a communication layer transmission matrix, and an information layer decision matrix using the incidence matrix;

[0063] The physical layer status matrix describes the status of each physical node and its topological connection relationship in the physical layer model through the incidence matrix;

[0064] The secondary equipment layer deployment matrix describes the spatial distribution of secondary equipment nodes in the cyber-physical coupling layer model and their topological connection relationship with physical nodes through the incidence matrix;

[0065] The communication layer transmission matrix describes the information uplink and downlink transmission characteristics of the communication network in the cyber-physical coupling layer model. The uplink transmission uploads the operating status of the physical layer model to the information layer model, and the downlink transmission sends the control instructions of the information layer model to the physical layer model;

[0066] The information layer decision matrix describes the interaction relationship between the decision-making algorithm of the control center in the information layer model and the physical layer model. The control center generates control instructions based on the operating status of the physical layer model and sends them to the physical layer model through the communication layer transmission matrix.

[0067] The closed-loop control mechanism includes the mechanism for the information layer model to monitor the physical layer model, the mechanism for the control center of the information layer model to optimize decisions, and the mechanism for the power network of the physical layer model to be controlled;

[0068] Mechanism for the information layer model to monitor the physical layer model: The information layer model collects the power network status information from the physical layer model through the uplink matrix of the communication network and the secondary equipment deployment matrix to form an information collection matrix;

[0069] Mechanism for the control center of the information layer model to optimize decisions: The control center generates optimization instructions using the decision-making algorithm based on the collected status information to form an instruction issuance matrix;

[0070] Mechanism for the power network of the physical layer model to be controlled: The optimization instructions are sent to the physical layer model through the downlink matrix of the communication network, and the physical layer model adjusts its operating status according to the instructions to form a controlled matrix;

[0071] The adjusted power network status information is uploaded as a new round of data to form a closed-loop control.

[0072] The expression of the mechanism for the information layer model to monitor the physical layer model is as follows:

[0073]

[0074] In the formula, C receieve is the information collection matrix of the information layer model; S up is the uplink matrix of the communication network; R is the secondary equipment deployment matrix; P 0is the initial power network state matrix of the physical layer model;

[0075] The expression of the optimization decision-making mechanism of the control center in the information layer model is as follows:

[0076] C send = G(C receive ) (2)

[0077] In the formula, C send is the command issuance matrix of the information layer model; G(·) is the decision-making algorithm of the information layer model;

[0078] The expression of the power network controlled mechanism in the physical layer model is as follows:

[0079]

[0080] In the formula, P control is the controlled matrix of the physical layer model after receiving the command, S down is the downlink matrix of the communication network; R is the secondary equipment deployment matrix.

[0081] The entity components include power generation devices, substation equipment and distributed energy devices;

[0082] The intelligent terminal devices include DTU and FTU.

[0083] In the present invention, by hierarchically constructing the physical layer model, the cyber-physical coupling layer model and the information layer model, and using the correlation matrix to realize multi-level coupling, the information flow transmission and dynamic regulation process are clearly described. Compared with the single-level modeling method in the prior art, the present invention can more accurately describe the complex interaction mechanism of the distribution network cyber-physical system, and provides a theoretical basis for the optimal operation and hierarchical management of the system;

[0084] Through the closed-loop control mechanism, the system can collect the operation state of the physical layer model in real time, and dynamically adjust the control command according to the decision-making algorithm of the information layer model, significantly improving the response speed and regulation accuracy of the system;

[0085] The present invention introduces the information layer to realize the real-time regulation decision-making of the distribution network. When a fault occurs, the system can quickly locate the fault point and generate an optimization command to complete operations such as fault isolation and load transfer, minimizing the power outage probability of the non-fault area and improving the reliability and power supply continuity of the system;

[0086] The present invention is applicable to various operation scenarios such as the optimal operation, hierarchical management and safety regulation of modern intelligent distribution networks. By comprehensively considering the coupling relationship and correlation characteristics between each layer, the system can flexibly respond to different operation requirements and provide technical support for the intelligent development of the distribution network.

[0087] In this application, a unified model of the distribution network cyber-physical system is built with a 33-node distribution network system as an example. Under normal circumstances, the information transmission channels are all in a fully coupled state and lossless. As the core control unit of the information network, the master station server integrates optimization decision algorithms such as centralized feeder automation. The distributed terminal devices have two-way communication functions. They can not only collect and upload data information such as the operating parameters and switch states of physical nodes, but also receive and execute the control instructions issued by the master station to realize remote operation of sectional switches and circuit breakers. In addition, all types of terminal devices have the dual functions of data collection and instruction execution, and can perform real-time monitoring and remote control of the physical nodes they are connected to.

[0088] Compare the unified model of the distribution network cyber-physical system proposed by the present invention with the traditional distribution network model, and observe the total load loss after the system resumes stable operation when a grounding short-circuit fault occurs on the physical line.

[0089] The simulation results under different conditions are as Figure 2 shown. It can be seen from the curves in the figure that under the same line grounding fault, the traditional distribution network model shows a significantly higher load loss compared to the distribution network cyber-physical system model. When the traditional distribution network encounters a permanent fault, it can only rely on circuit breakers and fixed protection logic to achieve overcurrent protection. The operation of all sectional switches depends on manual operation on-site and cannot achieve remote control. The time required to restore power supply may reach several hours or even longer. However, the distribution network cyber-physical system integrates an advanced information system and intelligent terminal devices, realizes the deep coupling of the power network and the information network, can accurately identify the location of the fault, and perform dynamic regulation, thereby minimizing the power outage range and verifying the effectiveness of the modeling method proposed by the present invention.

[0090] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0091] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. An integrated modeling method for a cyber-physical system of a distribution network considering multi-layer coupling, characterized in that It includes the following steps: According to the entity architecture of the power distribution network cyber-physical system, divide the system levels, where the system levels include the physical layer, the cyber-physical coupling layer, and the information layer; Using the complex network theory framework, transform the entity architecture of the power distribution network cyber-physical system into a graph theory model, and represent the system topology and functional interaction characteristics by establishing a multi-layer network structure; Build the physical layer model, the cyber-physical coupling layer model, and the information layer model layer by layer, and use the incidence matrix to describe the coupling relationship and correlation characteristics between the models of each layer; According to the information transfer process of the power distribution network cyber-physical system, establish a closed-loop control mechanism to form an integrated dynamic model of the power distribution network cyber-physical system.

2. The integrated modeling method of the cyber-physical system for a distribution network considering multi-layer coupling according to claim 1, wherein Construct a multi-layer network structure G g as follows: G g =(V g , E g ); Among which V g represents the node set, including physical nodes, secondary equipment nodes and information nodes; E g represents the edge set, which is used to describe the connection relationships between levels.

3. The integrated modeling method of the cyber-physical system for the distribution network considering multi-layer coupling according to claim 2, characterized in that, Model the entity components in the physical layer of the power distribution network cyber-physical system as physical nodes; Model the intelligent terminal devices in the cyber-physical coupling layer of the power distribution network cyber-physical system as secondary device nodes; Model the control center and the information network in the information layer of the power distribution network cyber-physical system as information nodes.

4. The integrated modeling method of the cyber-physical system of the distribution network considering multi-layer coupling according to claim 3, wherein Build the physical layer model, the cyber-physical coupling layer model, and the information layer model layer by layer, and use the incidence matrix to describe the coupling relationship and correlation characteristics between the models of each layer. Specifically, it includes the following steps: Use the incidence matrix to establish the physical layer state matrix, the secondary device layer deployment matrix, the communication layer transmission matrix, and the information layer decision matrix; The physical layer state matrix describes the states of each physical node in the physical layer model and their topological connection relationships through the incidence matrix; The secondary device layer deployment matrix describes the spatial distribution of secondary device nodes in the cyber-physical coupling layer model and their topological connection relationships with physical nodes through the incidence matrix; The communication layer transmission matrix describes the information up and down transmission characteristics of the communication network in the cyber-physical coupling layer model. The up transmission uploads the operating state of the physical layer model to the information layer model, and the down transmission sends the control instructions of the information layer model to the physical layer model; The information layer decision matrix describes the interaction relationship between the decision-making algorithm of the control center in the information layer model and the physical layer model. The control center generates control instructions according to the operating state of the physical layer model and sends them to the physical layer model through the communication layer transmission matrix.

5. The integrated modeling method of the cyber-physical system for a distribution network considering multi-layer coupling according to claim 4, characterized in that, The closed-loop control mechanism includes the information layer model monitoring the physical layer model mechanism, the information layer model control center optimization decision-making mechanism, and the physical layer model power network controlled mechanism; The information layer model monitoring the physical layer model mechanism: The information layer model collects the power network state information from the physical layer model through the up matrix of the communication network and the secondary device deployment matrix to form an information collection matrix; The information layer model control center optimization decision-making mechanism: The control center generates optimization instructions using the decision-making algorithm according to the collected state information to form an instruction sending matrix; The physical layer model power network controlled mechanism: The optimization instructions are sent to the physical layer model through the down matrix of the communication network, and the physical layer model adjusts its operating state according to the instructions to form a controlled matrix; The adjusted power network state information is uploaded as a new round of data to form a closed-loop control.

6. The integrated modeling method of the cyber-physical system of the distribution network considering multi-layer coupling according to claim 5, characterized in that, The expression of the information layer model monitoring the physical layer model mechanism is as follows: where C receieve is the information acquisition matrix of the information layer model; S up is the uplink matrix of the communication network; R is the secondary equipment deployment matrix; P 0 is the initial power network state matrix of the physical layer model; The expression of the information layer model control center optimization decision-making mechanism is as follows: C send = G(C receive ) (2) where C send is the instruction distribution matrix of the information layer model; G(·) is the decision-making algorithm of the information layer model; The expression of the physical layer model power network controlled mechanism is as follows: Where, P control is the controlled matrix after the physical layer model receives the instruction, and S down is the downlink matrix of the communication network; R is the secondary equipment deployment matrix.

7. The integrated modeling method of the cyber-physical system for a distribution network considering multi-layer coupling according to claim 6, characterized in that The physical components include power generation devices, power transformation equipment, and distributed energy devices; The intelligent terminal devices include DTUs and FTUs.

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