A cyber-physical system simulation method for automatic voltage control of active distribution networks

Abstract

The present application provides an information-physical system simulation method for automatic voltage control of an active distribution network. Based on the control center node of the information system, the information system is divided into a measurement upstream system and a downstream execution system. The topology of the above two systems is modeled as a tree structure model; the information flow in the measurement upstream system and the downstream execution system is recursively calculated to obtain a measurement information flow set and an execution information flow set; based on the linearization parameters of the physical system of the active distribution network, the measurement information flow set and the execution information flow set, the information system and the physical system are simulated for information-physical coupling to determine the voltage change of the active distribution network within the set simulation time. The present application models the information system in a tree shape, recursively calculates the information flow, and calculates the voltage change within the set simulation time by coupling the actual values ​​and parameters of the physical system, so as to achieve a quantitative evaluation of the impact of the AVC system on the operational risk of the active distribution network.

Description

Technical Field

[0001] The present application relates to the technical field of active power distribution networks, and in particular to a cyber-physical system simulation method for automatic voltage control of active power distribution networks. Background Art

[0002] As a unified entity of computing and physical processes, the cyber-physical system (CPS) is a new generation of intelligent systems that integrate computing, communication, and control. Based on environmental perception, CPS is a controllable, trustworthy, and scalable networked physical device system that deeply integrates computing, communication, and control capabilities. It achieves deep integration and real-time interaction through feedback loops between computing and physical processes to add or expand new functions, monitoring or controlling a physical entity in a safe, reliable, efficient, and real-time manner. The introduction and development of CPS has promoted the deep integration of traditional power systems and power information systems, providing ideas and approaches for the development of smart grids.

[0003] An active distribution network (ADN) is a distribution network that actively manages distributed power sources, energy storage devices, and customer loads in both directions. This network is able to fully leverage the positive impact of new power sources and loads, such as distributed power sources. The economical, safe, and stable operation of an active distribution network depends heavily on its supporting information systems, including measurement, state estimation, optimization calculation, and control. Therefore, an active distribution network constitutes a typical cyber-physical system. The physical side of a CPS primarily refers to the primary power system, including various substations, power generation equipment, loads, and power grids. The information side encompasses the measurement, communication, simulation, and control aspects of the power system.

[0004] The Automatic Voltage Control (AVC) system is a key component of active distribution networks. The AVC system automatically adjusts the voltage at each node in the distribution network, playing a crucial role in maintaining safe, stable, and efficient operation. While the addition of the AVC system makes active distribution networks more efficient, it also increases their reliance on information systems. Disturbances on the information side can affect the operation of the active distribution network, impacting its normal operation.

[0005] Current active distribution network security assessments primarily focus on faults in the physical grid system, simulating the fault scenario and the grid's post-fault operation, and evaluating the simulation results. Current security assessments primarily focus on the primary, or physical, side of the grid, with fewer simulations of faults on the secondary, or information, side. Furthermore, fault simulation and assessment processes focus solely on the physical side, without integrating the information side, resulting in a single, unstructured assessment approach. Summary of the Invention

[0006] The present application provides an information-physical system simulation method for automatic voltage control of an active distribution network to solve the problems in the existing technology that active distribution network safety assessment rarely uses information-side faults as simulation objects, the physical side and the information side are separated during the assessment process, and the assessment of the impact of the information system operation on the operation of the active distribution network is not accurate enough.

[0007] In a first aspect, the present application provides a cyber-physical system simulation method for active distribution network automatic voltage control, comprising:

[0008] The information system of the active distribution network includes a control center node. Based on the control center node, the information system is divided into an upstream measurement system and a downstream execution system. The simulation method includes:

[0009] Model the topology of the measurement upstream system and the downstream execution system as a tree structure model;

[0010] Based on the tree structure model, the information flow in the measurement uplink system is recursively calculated to obtain the measurement information flow set of the control center node; based on the tree structure model, the information flow in the downlink execution system is recursively calculated to obtain the execution information flow set of the control center node;

[0011] Based on the linearization parameters, measurement information flow set and execution information flow set of the physical system of the active distribution network, the information system and the physical system are simulated by information-physical coupling to realize the voltage variation simulation of the active distribution network.

[0012] In a possible implementation, the information system of the active power distribution network further includes: a measurement node, an execution node, a transmission branch, and a transmission node;

[0013] The simulation method also includes:

[0014] All measurement nodes, transmission nodes and transmission branches upstream of the control center node are defined as a measurement uplink system as a whole;

[0015] All execution nodes, transmission nodes and transmission branches downstream of the control center node are defined as a downstream execution system as a whole.

[0016] In one possible implementation, modeling the topology of the measurement uplink system and the downlink execution system as a tree structure model includes:

[0017] For the measurement uplink system, the control center node serves as the root node and the measurement nodes serve as leaf nodes;

[0018] For the downlink execution system, the control center node serves as the root node and the execution node serves as the leaf node.

[0019] The topology information of the measurement uplink system and downlink execution system is:

[0020] The measurement node is represented as:

[0021] Among them, P type Refers to the physical quantity type associated with the measurement node, P idx Refers to the physical quantity number associated with the measurement node, Refers to the transmission branch number downstream of the measurement node;

[0022] The execution node is represented as:

[0023] Among them, A type Refers to the executor type associated with the execution node, A idx Refers to the executor number associated with the execution node, Refers to the transmission branch number upstream of the execution node;

[0024] The transmission branch is expressed as:

[0025] in, Refers to the upstream information node type, Refers to the upstream information node number, Refers to the downstream information node type, Refers to the downstream information node number;

[0026] The control center node is represented as:

[0027] in, Refers to the upstream information branch number, Refers to the downstream information branch number;

[0028] The transport node is represented as:

[0029] in, Refers to the set of upstream information branch numbers, Refers to the collection of downstream information branches.

[0030] In one possible implementation, the information flow in the measurement uplink system is recursively calculated based on a tree structure model, and the measurement information flow set of the control center node is obtained, including:

[0031] The information flow transmitted on the information element in the uplink measurement system is defined as:

[0032] ((P type ,P idx ),t FL ,f FL ),

[0033] Among them, P type is the type of physical quantity represented by the information in the information flow, P idx is the physical quantity number represented by the information in the information flow, t FL is the cumulative delay time of the information in the information flow, f FL is the cumulative transfer function of the amount of information in the information flow;

[0034] Select each control center node separately and perform recursive operations on each control center node;

[0035] Establish a recursive function, taking the information element delay, information element transfer function and topology information of an information element as input:

[0036] If the information element input by the recursive function is a measurement node, the information flow set of the information element is recorded according to the physical quantity associated with the information element: Among them, P type Refers to the physical quantity type associated with the information element, P idx Refers to the physical quantity number associated with the information element, I refers to the information element, Refers to the delay of the information element, f t I Refers to the information element transfer function;

[0037] If the information element input by the recursive function is not a measurement node, each information flow in the information flow set of the upstream information element of the information element is recorded as FL':

[0038]

[0039] And the information flow FL' of the upstream information element is added to the information flow set of the information element.

[0040] For each upstream information element, repeat the recursive operation on the information element.

[0041] In one possible implementation, the information flow in the downstream execution system is recursively calculated based on the tree structure model, and the execution information flow set of the control center node is obtained, including:

[0042] The information flow transmitted on the information element in the downlink execution system is defined as:

[0043] ((A type ,A idx ),t FL ,f FL );

[0044] Among them, A type is the execution type represented by the information volume in the information flow, A idx is the number of the execution quantity represented by the information in the information flow, t FL is the cumulative delay time of the information in the information flow, f FL is the cumulative transfer function of the amount of information in the information flow;

[0045] Select each control center node separately and perform recursive operations on each control center node;

[0046] Establish a recursive function, taking the information element delay, information element transfer function and topology information of an information element as input:

[0047] If the information element input by the recursive function is an execution node, the information flow set of the information element is recorded according to the physical quantity associated with the information element: Among them A type Refers to the execution type associated with the information element, A idx Refers to the execution quantity number associated with the information component, I refers to the information component, Refers to the information element delay, f t I Refers to the information element transfer function;

[0048] If the information element input by the recursive function is not an execution node, the information flow in the information flow set of the downstream information element of the information element is recorded as FL';

[0049]

[0050] The information flow FL' of the downstream information element is added to the information flow set of the information element.

[0051] For each downstream information element, repeat the recursive operation on the information element.

[0052] In one possible implementation, cyber-physical coupling simulation of the cyber system and the physical system is performed based on the linearization parameters, measurement information flow set, and execution information flow set of the physical system of the active distribution network. Simulating the voltage variation of the active distribution network includes:

[0053] Calculate the amount of information actually received by the executor associated with the execution node based on the measurement information flow set and the execution information flow set;

[0054] Calculating the change in injected active power and the change in injected reactive power based on the amount of information actually received by the actuator associated with the execution node;

[0055] The voltage variation of the active distribution network within the set simulation time is calculated based on the linearization parameters, the variation of the injected active power and the variation of the injected reactive power.

[0056] In one possible implementation, calculating the amount of information actually received by the executor associated with the execution node based on the measurement information flow set and the execution information flow set includes:

[0057] Model information components using delay and transfer functions:

[0058] Let the delay be t d With the transfer function f t , the input information of a single information element is recorded as x(t), and the output information of a single information element is recorded as y(t). The relationship between the output information and the input information of a single information element is: y(t) = f t (x(tt d )).

[0059] For any time t, according to the measurement node (P type ,P idx ) corresponds to the actual value x(t) of the physical quantity and the definition of the measurement information flow ((P type ,P idx ),t FL ,f FL ), calculate the measurement value y(t) received by the information element: y(t) = f FL (x(tt FL )).

[0060] At any time t, according to the measurement value set {y(t)} received by each control center node and the control center node logic f c Delay t with the control center node c , calculate the execution information set sent by the control center node:

[0061] {w(t)}=f c ({y(tt c )});

[0062] For any time t, according to the definition of execution information flow ((A type ,A idx ),t FL ,f FL) and the execution node (A type ,A idx ) corresponds to the amount of execution information w(t), and calculates the amount of information u(t) actually received by the executor associated with the execution node: u(t) = f FL (w(tt FL )).

[0063] In one possible implementation, calculating the change in injected active power and the change in injected reactive power based on the amount of information actually received by the actuator associated with the execution node includes:

[0064] Based on the actual amount of information u(t) received by the actuator associated with the execution node at any time t and the dynamic characteristics of each actuator, after calculating the simulation step Δt, the change vector ΔP of the injected active power and the change vector ΔQ of the injected reactive power are calculated; if the dynamic characteristics of the i-th actuator are Change in injected active power ΔP i and the change in injected reactive power ΔQ i for:

[0065]

[0066] The dimension of the change vector ΔP of injected active power and the change vector ΔQ of injected reactive power is equal to the number of nodes in the power grid, and the nth element thereof is the sum of the change in the injected active power and the change in the injected reactive power of the actuator at the nth node in the power grid.

[0067] In one possible implementation, a method for calculating the linearization parameter includes:

[0068] Calculate the linearization parameters of the active distribution network based on the physical system parameters of the active distribution network:

[0069] X=F T diag{x}F,

[0070] R=F T diag{r}F

[0071] Where X, R are linearization parameters, F is the branch-road correlation matrix, x is the branch reactance vector, and r is the branch resistance matrix.

[0072] In one possible implementation, calculating the voltage variation of the active distribution network within a set simulation time based on the linearization parameter, the variation of the injected active power, and the variation of the injected reactive power includes:

[0073] The voltage variation of the active distribution network is calculated based on the linearization parameters of the active distribution network and the change vector ΔP of the injected active power and the change vector ΔQ of the injected reactive power:

[0074] ΔV=RΔP+XΔQ;

[0075] Let the simulation time increase by the simulation step Δt;

[0076] If the simulation time t is less than the maximum simulation time t max , then return to recalculate the amount of information u(t) actually received by the actuator, otherwise end the simulation.

[0077] In summary, this application proposes a cyber-physical coupling simulation algorithm for the automatic voltage control system in the active distribution network, as a supplement to the current distribution network security assessment model. This application first models and simulates the cyber system, and then couples it with the physical system to obtain a cyber-physical system simulation model. By comparing the voltage changes during normal operation and failure of the information side in the above simulation model, the impact of the automatic voltage control system (AVC) on the operational risk of the active distribution network is quantitatively evaluated. This application can accurately calculate the impact of the information system on the operation of the active distribution network while reducing the amount of calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0079] Figure 1 This is a flowchart of the implementation of the cyber-physical system simulation method for active distribution network automatic voltage control provided by the embodiment of the present application;

[0080] Figure 2 This is a structural diagram of an information system equivalent tree model of the information-physical system simulation method for automatic voltage control of an active distribution network provided in an embodiment of the present application;

[0081] Figure 3 This is a diagram of a non-tree-like original upstream measurement system and its equivalent tree-like upstream measurement system of the cyber-physical system simulation method for active distribution network automatic voltage control provided by an embodiment of the present application;

[0082] Figure 4 This is a voltage curve diagram during normal operation of the cyber-physical system simulation method for active distribution network automatic voltage control provided by an embodiment of the present application;

[0083] Figure 5 This is a voltage curve diagram when a fault occurs in the information-physical system simulation method for automatic voltage control of the active distribution network provided in an embodiment of the present application. DETAILED DESCRIPTION

[0084] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0085] In order to make the purpose, technical solutions and advantages of this application clearer, specific embodiments will be described below with reference to the accompanying drawings.

[0086] The present application provides an information-physical system simulation method for an automatic voltage control system of an active power distribution network, which classifies information elements in the information system of the active power distribution network, expresses mathematical models, establishes equivalent tree models, and labels topological information types; and defines and recursively calculates information flows transmitted on information elements. Then, the simulation of the information system is achieved by substituting the actual values ​​of the physical quantities corresponding to the information elements into the information flow definition and calculation method. Finally, based on the information system simulation results and the physical system linearization parameters, the present application calculates the voltage change of the active power distribution network within a given physical system initial state and a set simulation time, thereby achieving coupled simulation of the information system and the physical system.

[0087] Figure 1 This is a flowchart for implementing the cyber-physical system simulation method for active distribution network automatic voltage control provided in an embodiment of the present application.

[0088] The information system of the active distribution network includes a control center node, and the information system is divided into a measurement upstream system and a downstream execution system based on the control center node.

[0089] In an embodiment of the present application, the process of dividing the information system into a measurement upstream system and a downstream execution system includes: first, based on the impact of different elements in the information system of the active power distribution network on the amount of information and the interaction relationship with the physical system, the information elements are divided into five categories: measurement nodes, execution nodes, transmission branches, transmission nodes and control center nodes, and a mathematical model is used to describe the impact of each information element on the amount of information; then, each control center node is extracted, and all measurement nodes, transmission nodes and transmission branches upstream of each control center node are defined as a whole as the measurement upstream system, and all execution nodes, transmission nodes and transmission branches downstream of each control center node are defined as a whole as the downstream execution system.

[0090] In some embodiments, information elements may be categorized as:

[0091] Measurement node: A measurement node is a node-type information element connected to a downstream information branch. Each measurement node is bound to a physical quantity in the physical system. Its function is to convert the physical quantity in the physical system into information in the information system and output it to the downstream branch.

[0092] Execution node: An execution node is a node-type information element connected to an upstream information branch. Each execution node is bound to an actuator in the physical system. Its function is to output the information received from the upstream information branch as instructions to the actuator, changing the actuator state and thus affecting the physical system.

[0093] Transmission branch: A transmission branch is a branch-type information element that is bound to an upstream node and a downstream node. Its function is to output the information received at the upstream node to the downstream node. Under normal circumstances, the transmission branch does not change the value of the information.

[0094] Transmission node: A transmission node is a node-type information element. When measuring transmission volume, the transmission node is connected to a downstream branch and one or more upstream branches. When measuring transmission volume, the transmission node is connected to one upstream branch or multiple downstream branches. Its function is to output the information volume received by the upstream branch to the downstream branch. Under normal circumstances, the transmission node does not change the value of the information volume.

[0095] Control center node: The control center node is a node-type information element, connected to an upstream branch and a downstream branch. Its function is to use the quantity measurement received by the upstream branch to calculate the execution quantity and output it to the downstream branch.

[0096] In some embodiments, mathematically modeling each information element includes: calculating the effect of a single information element on the amount of information by a delay t d With the transfer function f t Expressed as x(t), the amount of information input to a single information element is recorded as x(t), and the amount of information output is recorded as y(t). According to the properties of its delay and transmission function, the relationship between the output and input of a single information element at any time t can be described as: y(t) = f t (x(tt d )).

[0097] For each control center node in the information system, all its upstream measurement nodes, transmission nodes and transmission branches are taken as a whole and called the measurement upstream system, and all its downstream execution nodes, transmission nodes and transmission branches are taken as a whole and called the downstream execution system.

[0098] Reference Figure 1 ,The cyber-physical system simulation method for automatic voltage control of active distribution network,includes:

[0099] In step 101 , the topology of the measurement uplink system and the downlink execution system is modeled as a tree structure.

[0100] In some embodiments, considering the directional transmission characteristics of information systems, the information system can be equivalently modeled as a tree model. Step 101 may include: for the measurement uplink system, the control center node is used as the root node and the measurement nodes are used as leaf nodes; for the downlink execution system, the control center node is used as the root node and the execution nodes are used as leaf nodes.

[0101] Figure 2 Shows an information system and its measurement upstream system and downstream execution system.

[0102] For each control center node 40 in the information system, all its upstream measurement nodes 10, transmission branches 20, and transmission nodes 30 are called the measurement uplink system 60; all its downstream transmission branches 20, transmission nodes 30, and execution nodes 50 are called the downlink execution system 70.

[0103] In some embodiments, for some information systems, the topology of the measurement uplink system or downlink execution system is not tree-like, or there is a situation where an information element is associated with multiple control center nodes. In this case, an equivalent tree-like information system can be formed by introducing a copy of the actual information element as a virtual information element.

[0104] Figure 3 The diagram shows the non-tree-shaped original measurement uplink system provided by the above embodiment and its corresponding equivalent tree-shaped uplink measurement system.

[0105] As shown in the figure, in the non-tree-like original measurement uplink system 100, the information collected by measurement node 10 in the original measurement uplink system is divided into two transmission branches 80 and 90 for transmission via transmission node 30, resulting in a non-tree-like system topology. In this case, virtual information elements 10', 20', and 30' can be introduced as replicas of information elements 10, 20, and 30 to establish an equivalent measurement uplink system 110, which can be modeled as a tree. For systems where the downlink execution system topology is not a tree, an equivalent tree-like downlink execution system can also be established by introducing virtual information elements.

[0106] For each information element in the equivalent tree-like measurement uplink system and the equivalent tree-like downlink execution system, all information elements associated therewith need to be stored, thereby achieving the purpose of storing the information system topology information.

[0107] In some embodiments, depending on the type of information element, the topology information type of the information element for measuring the uplink system and the downlink execution system can be defined as:

[0108] Measurement nodes:

[0109] Among them, P type Refers to the physical quantity type associated with the measurement node, P idx Refers to the physical quantity number associated with the measurement node, Refers to the transmission branch number downstream of the measurement node;

[0110] Execution node:

[0111] Among them A type Refers to the executor type associated with the execution node, A idx Refers to the executor number associated with the execution node, Refers to the transmission branch number upstream of the execution node;

[0112] Transmission branch:

[0113] in Refers to the upstream information node type, Refers to the upstream information node number, Refers to the downstream information node type, Refers to the downstream information node number;

[0114] Control center node:

[0115] in Refers to the upstream information branch number, Refers to the downstream information branch number;

[0116] Transmission Node:

[0117] in Refers to the set of upstream information branch numbers, Refers to the collection of downstream information branches.

[0118] In step 102, a recursive calculation is performed on the information flow in the measurement uplink system based on the tree structure model to obtain a measurement information flow set of the control center node.

[0119] The measurement uplink system can transmit information on the primary and / or secondary sides of the distribution network, such as the voltage of each node on the physical side. The information in the measurement uplink system is transmitted from the measurement node to the control center node.

[0120] In some embodiments, step 102 may include:

[0121] Step 1021: Define the information flow transmitted on the information element in the uplink measurement system as follows: ((P type ,P idx ),t FL ,fFL ),

[0122] Among them, P type is the type of physical quantity represented by the information in the information flow, P idx is the physical quantity number represented by the information in the information flow, t FL is the cumulative delay time of the information in the information flow, f FL is the cumulative transfer function of the amount of information in the information flow;

[0123] Step 1022: Select each control center node separately and perform recursive operations on each control center node;

[0124] Step 1023: Establish a recursive function, using the information element delay, information element transfer function, and topology information of an information element as inputs of the recursive function:

[0125] Step 1024: If the information element input by the recursive function is a measurement node, the information flow set of the information element is recorded according to the physical quantity associated with the information element: Among them, P type Refers to the physical quantity type associated with the information element, P idx Refers to the physical quantity number associated with the information element, I refers to the information element, Refers to the delay of the information element, f t I Refers to the information element transfer function;

[0126] Step 1025: If the information element input to the recursive function is not a measurement node, each information flow in the information flow set of the upstream information element of the information element is recorded as FL':

[0127]

[0128] And the information flow FL' of the upstream information element is added to the information flow set of the information element.

[0129] Step 1026: Repeat the recursive operation on each upstream information element.

[0130] In step 103, the information flow in the downlink execution system is recursively calculated based on the tree structure model to obtain the execution information flow set of the control center node.

[0131] The downstream execution system can transmit control instructions for the distribution network, such as adjusting the input or output of a generator. The direction of information transmission in the downstream execution system is from the control center node to the execution node.

[0132] In some embodiments, step 103 may include:

[0133] Step 1031: Define the information flow transmitted on the information element in the downlink execution system as follows:

[0134] ((A type ,A idx ),t FL ,f FL ),

[0135] Among them A type is the execution type represented by the information volume in the information flow, A idx is the number of the execution quantity represented by the information in the information flow, t FL is the cumulative delay time of the information in the information flow, f FL is the cumulative transfer function of the amount of information in the information flow;

[0136] Step 1032: Select each control center node separately and perform recursive operations on each control center node;

[0137] Step 1033: Establish a recursive function, using the information element delay, information element transfer function, and topology information of an information element as inputs of the recursive function:

[0138] Step 1034: If the information element input by the recursive function is an execution node, record the information flow set of the information element according to the physical quantity associated with the information element: Among them A type Refers to the execution type associated with the information element, A idx Refers to the execution quantity number associated with the information component, I refers to the information component, Refers to the information element delay, f t I Refers to the information element transfer function;

[0139] Step 1035: If the information element input to the recursive function is not an execution node, the information flow in the information flow set of the downstream information element of the information element is recorded as FL':

[0140]

[0141] The information flow FL' of the downstream information element is added to the information flow set of the information element.

[0142] Step 1036: Repeat the recursive operation on each downstream information element.

[0143] In step 104 , based on the linearization parameters of the physical system of the active distribution network, the measurement information flow set, and the execution information flow set, a cyber-physical coupling simulation is performed on the cyber system and the physical system to achieve voltage variation simulation of the active distribution network.

[0144] The voltage fluctuation of the power grid can be used as one of the important criteria for judging the safety of the power grid, especially the automatic voltage control system, and the severity of the fault.

[0145] In some embodiments, step 104 may include:

[0146] Step 1041: Calculate the amount of information actually received by the executor associated with the execution node based on the measurement information flow set and the execution information flow set;

[0147] Step 1042: Calculate the change in injected active power and the change in injected reactive power based on the amount of information actually received by the actuator associated with the execution node;

[0148] Step 1043 : Calculate the voltage variation of the active distribution network within a set simulation time based on the linearization parameters, the variation of the injected active power, and the variation of the injected reactive power.

[0149] In some embodiments, step 1041 may include:

[0150] At any time t, the relationship between the output information volume and the input information volume of a single information element is: y(t) = f t (x(tt d )), where t d is the delay, f t is the transfer function. According to the measurement node (P type ,P idx ) corresponds to the actual value x(t) of the physical quantity and the definition of the measurement information flow ((P type ,P idx ),t FL ,f FL ), calculate the measurement value y(t) received by the information element: y(t) = f FL (x(tt FL ));

[0151] According to the measurement value set {y(t)} received by each control center node and the control center node logic f c Delay t with the control center node c , calculate the execution information set sent by the control center node:

[0152] {w(t)}=f c ({y(tt c )});

[0153] For any time t, according to the definition of execution information flow ((A type ,A idx ),t FL ,f FL) and the execution node (A type ,A idx ) corresponds to the amount of execution information w(t), and calculates the amount of information u(t) actually received by the executor associated with the execution node: u(t) = f FL (w(tt FL )).

[0154] In some embodiments, step 1042 may include:

[0155] Based on the actual amount of information u(t) received by the actuator associated with the execution node at any time t and the dynamic characteristics of each actuator, after calculating the simulation step Δt, the change vector ΔP of the injected active power and the change vector ΔQ of the injected reactive power are calculated; if the dynamic characteristics of the i-th actuator are Change in injected active power ΔP i and the change in injected reactive power ΔQ i for:

[0156]

[0157] The dimension of the change vector ΔP of injected active power and the change vector ΔQ of injected reactive power is equal to the number of nodes in the power grid, and the nth element thereof is the sum of the change in the injected active power and the change in the injected reactive power of the actuator at the nth node in the power grid.

[0158] In some embodiments, step 1043 may include:

[0159] Calculate the linearization parameters of the active distribution network based on the physical system parameters of the active distribution network:

[0160] X=F T diag{x}F

[0161] R=F T diag{r}F,

[0162] Where X, R are linearization parameters, F is the branch-road correlation matrix, x is the branch reactance vector, and r is the branch resistance matrix.

[0163] The voltage variation of the active distribution network is calculated based on the linearization parameters of the active distribution network and the change vector ΔP of the injected active power and the change vector ΔQ of the injected reactive power:

[0164] ΔV=RΔP+XΔQ;

[0165] Let the simulation time increase by the simulation step Δt;

[0166] If the simulation time t is less than the maximum simulation time t max , then return to recalculate the amount of information u(t) actually received by the actuator, otherwise end the simulation.

[0167] In some embodiments, the present application obtains the physical state of the active distribution network at a specific time t as the initial state of the simulation, calculates the measurement information flow set {y(t)} and the execution information flow set {w(t)} at that time, and then calculates the amount of information u(t) actually received by the executor associated with the execution node.

[0168] In the above embodiment, the physical state of the active distribution network may include, but is not limited to, information such as the voltage V, power angle δ, active power P, and reactive power Q at each node. The initial value of the physical state can be obtained by performing a power flow calculation on the active distribution network based on the physical system parameters and operating conditions.

[0169] After a simulation step of Δt, the change vector ΔP of injected active power and the change vector ΔQ of injected reactive power are calculated based on the actual amount of information u(t) received by the actuator and the dynamic characteristics of each actuator. Substituting the linearization parameters X and R of the active distribution network into the active distribution network, the voltage change ΔV of the active distribution network AVC system is obtained: ΔV = RΔP + XΔQ. The simulation time is increased by the simulation step Δt, and the calculation of the actual amount of information u(t) received by the actuator, the change vector ΔP of injected active power, and the change vector ΔQ of injected reactive power are cyclically updated to obtain the voltage change ΔV until the simulation time is less than the maximum simulation time t. max The simulation ends.

[0170] In some embodiments, using the IEEE 14 power distribution network as an example, the technical solution of this application implements a cyber-physical system simulation of the IEEE 14 power distribution network. By simulating the operation of the distribution network during normal operation of the information system and after a delayed fault in the information system, the feasibility and effectiveness of this application in addressing information-side faults are verified.

[0171] Figure 4 and Figure 5 This figure shows the voltage variations of the IEEE 14 distribution network simulation method applied to this application. The information system's measurement nodes 1-14 are bound to IEEE 14 physical nodes 1-14, respectively. For example, measurement node 1 measures the voltage, power angle, active power, and reactive power of physical node 1, and so on. The information system's execution nodes are bound to the five generators and phase regulators in the physical system, meaning that a command sent by execution node 1 affects generator 1, and so on.

[0172] Taking the same physical system state as the initial state, that is, the same initial values ​​of voltage, power angle, active power and reactive power, Figure 4 and Figure 5 Compare the voltage changes of the distribution network when the information system is operating normally and after a fault occurs.

[0173] Figure 4 and Figure 5 Taking the same three nodes as an example, the voltage changes of the three nodes over time starting from the initial simulation moment are displayed.

[0174] Figure 4 With time period as the x-axis and voltage as the y-axis, the voltage change curve when the information system is operating normally is shown.

[0175] Figure 5 With the time period as the x-axis and the voltage as the y-axis, the voltage change curve after a delayed fault occurs in the information system is shown.

[0176] In some other possible embodiments, the unit of the time axis may also be seconds.

[0177] By comparison Figure 4 and Figure 5 :When the information system is operating normally, such as Figure 4 As shown in , the voltage of each physical node is basically stable after multiple control cycles and is close to 1; Figure 5 As shown in the figure, after a delayed fault occurs in the information system, the voltage fluctuates, posing a hidden danger to the system safety.

[0178] The embodiment of the present application provides an abstract modeling method for information system components through an information-physical system simulation method for automatic voltage control of an active distribution network, an information flow recursive calculation method based on a tree-type information system topology, and an information system simulation calculation method based on information flow. The information volume calculation method is combined with the physical system simulation method to propose an information-physical coupling simulation algorithm for automatic voltage control of an active distribution network, which can achieve quantitative evaluation of the impact of the AVC system on the operation risk of the active distribution network while reducing the amount of calculation.

[0179] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0180] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0181] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0182] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A cyber-physical system simulation method for automatic voltage control of an active distribution network, characterized in that: The information system of the active power distribution network includes a control center node. Based on the control center node, the information system is divided into a measurement uplink system and a downlink execution system. The simulation method includes: Model the topology of the measurement upstream system and the downstream execution system as a tree structure model; Based on the tree structure model, recursive calculation is performed on the information flow in the measurement uplink system to obtain the measurement information flow set of the control center node; based on the tree structure model, recursive calculation is performed on the information flow in the downlink execution system to obtain the execution information flow set of the control center node; Performing cyber-physical coupling simulation on the cyber system and the physical system based on the linearization parameters of the physical system of the active distribution network, the measurement information flow set, and the execution information flow set to achieve voltage variation simulation of the active distribution network; The recursive calculation of the information flow in the measurement uplink system based on the tree structure model to obtain the measurement information flow set of the control center node includes: Establishing a recursive function, taking the information element delay, the information element transfer function and the topology information of an information element as inputs of the recursive function; The information flow in the downlink execution system is recursively calculated based on the tree structure model to obtain the execution information flow set of the control center node, including: A recursive function is established, and the information element delay, the information element transfer function and the topology information of an information element are used as inputs of the recursive function.

2. The cyber-physical system simulation method for active distribution network automatic voltage control according to claim 1, characterized in that: The information system of the active power distribution network further includes: a measurement node, an execution node, a transmission branch and a transmission node; The simulation method further comprises: All measurement nodes, transmission nodes and transmission branches upstream of the control center node are defined as a measurement uplink system as a whole; All execution nodes, transmission nodes and transmission branches downstream of the control center node are defined as a downstream execution system as a whole.

3. The cyber-physical system simulation method for active distribution network automatic voltage control according to claim 2, characterized in that: The topology modeling of the measurement uplink system and the downlink execution system into a tree structure model includes: For the measurement uplink system, the control center node serves as the root node and the measurement node serves as the leaf node; For the downlink execution system, the control center node serves as the root node and the execution node serves as the leaf node; The topology information of the measurement uplink system and the downlink execution system is: The measurement node is represented as: Among them, P type Refers to the physical quantity type associated with the measurement node, P idx Refers to the physical quantity number associated with the measurement node, Refers to the transmission branch number downstream of the measurement node; The execution node is represented as: Among them, A type Refers to the executor type associated with the execution node, A idx Refers to the executor number associated with the execution node, Refers to the transmission branch number upstream of the execution node; The transmission branch is represented as: in, Refers to the upstream information node type, Refers to the upstream information node number, Refers to the downstream information node type, Refers to the downstream information node number; The control center node is represented as: in, Refers to the upstream information branch number, Refers to the downstream information branch number; The transmission node is represented as: in, Refers to the set of upstream information branch numbers, Refers to the collection of downstream information branches.

4. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 3, characterized in that: The recursive calculation of the information flow in the measurement uplink system based on the tree structure model to obtain the measurement information flow set of the control center node also includes: The information flow transmitted on the information element in the measurement uplink system is defined as: ((P type ,P idx ),t FL ,f FL ), Among them, P type is the type of physical quantity represented by the information in the information flow, P idx is the physical quantity number represented by the information in the information flow, t FL is the cumulative delay time of the information in the information flow, f FL is the cumulative transfer function of the amount of information in the information flow; Select each control center node separately and perform recursive operations on each control center node; If the information element input by the recursive function is a measurement node, the information flow set of the information element is recorded according to the physical quantity associated with the information element: Among them, P type Refers to the physical quantity type associated with the information element, P idx Refers to the physical quantity number associated with the information element, I refers to the information element, Refers to the delay of information components, Refers to the information element transfer function; If the information element input by the recursive function is not a measurement node, then each information flow in the information flow set of the upstream information element of the information element is recorded as FL', and adding the information flow FL' of the upstream information element to the information flow set of the information element; For each upstream information element, repeat the recursive operation on the information element.

5. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 4, characterized in that: The recursive calculation of the information flow in the downlink execution system based on the tree structure model to obtain the execution information flow set of the control center node also includes: The information flow transmitted on the information element in the downlink execution system is defined as: ((A type ,A idx ),t FL ,f FL ); Among them, A type is the execution type represented by the information volume in the information flow, A idx is the number of the execution quantity represented by the information in the information flow, t FL is the cumulative delay time of the information in the information flow, f FL is the cumulative transfer function of the amount of information in the information flow; Select each control center node separately and perform recursive operations on each control center node; If the information element input by the recursive function is an execution node, the information flow set of the information element is recorded according to the physical quantity associated with the information element: Among them, A type Refers to the execution type associated with the information element, A idx Refers to the execution quantity number associated with the information component, I refers to the information component, Refers to the information component delay, Refers to the information element transfer function; If the information element input by the recursive function is not an execution node, the information flow in the information flow set of the downstream information element of the information element is recorded as FL'. and adding the information flow FL' of the downstream information element to the information flow set of the information element; For each downstream information element, repeat the recursive operation on the information element.

6. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 5, characterized in that: The method performs cyber-physical coupling simulation on the cyber system and the physical system based on the linearization parameters of the physical system of the active power distribution network, the measurement information flow set, and the execution information flow set to realize voltage variation simulation of the active power distribution network, including: Calculating the amount of information actually received by the executor associated with the execution node based on the measurement information flow set and the execution information flow set; Calculating the change in injected active power and the change in injected reactive power based on the amount of information actually received by the actuator associated with the execution node; The voltage variation of the active power distribution network within a set simulation time is calculated based on the linearization parameters, the variation of the injected active power, and the variation of the injected reactive power.

7. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 6, characterized in that: The calculating, based on the measurement information flow set and the execution information flow set, the amount of information actually received by the executor associated with the execution node includes: Model information components using delay and transfer functions: Let the delay be t d With the transfer function f t , the input information of a single information element is recorded as x(t), and the output information of a single information element is recorded as y(t). The relationship between the output information and the input information of a single information element is: y(t) = f t (x(tt d )); For any time t, according to the measurement node (P type ,P idx ) corresponds to the actual value x(t) of the physical quantity and the measurement information flow definition ((P type ,P idx ),t FL ,f FL ), calculate the measurement value y(t) received by the information element: y(t) = f FL (x(tt FL )); At any time t, according to the measurement value set {y(t)} received by each control center node and the control center node logic f c Delay t with the control center node c , calculate the execution information volume set issued by the control center node: {w(t)}=f c ({y(t-t c )}); For any time t, according to the execution information flow definition ((A type ,A idx ),t FL ,f FL ) and the execution node (A type ,A idx ) corresponds to the amount of execution information w(t), and calculates the amount of information u(t) actually received by the executor associated with the execution node: u(t) = f FL (w(tt FL )).

8. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 6, characterized in that: The calculating the change in injected active power and the change in injected reactive power based on the amount of information actually received by the actuator associated with the execution node includes: Based on the actual amount of information u(t) received by the actuator associated with the execution node at any time t and the dynamic characteristics of each actuator, after calculating the simulation step Δt, the change vector ΔP of the injected active power and the change vector ΔQ of the injected reactive power are calculated; if the dynamic characteristics of the i-th actuator are Change in injected active power ΔP i and the change in injected reactive power ΔQ i for: The dimension of the active power injection change vector ΔP and the reactive power injection change vector ΔQ is equal to the number of nodes in the power grid, and the nth element thereof is the sum of the changes in the active power injection and reactive power injection of the actuator at the nth node in the power grid.

9. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 1, characterized in that: The calculation method of the linearization parameter includes: Calculate the linearization parameters of the active distribution network based on the physical system parameters of the active distribution network: X=F T diag{x}F, R=F T diag{r}F, Wherein, X, R are the linearization parameters, F is the branch-road correlation matrix, x is the branch reactance vector, and r is the branch resistance matrix.

10. The cyber-physical system simulation method for active power distribution network automatic voltage control according to claim 6, characterized in that: The calculating of the voltage variation of the active distribution network within a set simulation time based on the linearization parameter, the variation of the injected active power, and the variation of the injected reactive power includes: Based on the linearization parameters R and X of the active distribution network, the change vector ΔP of the injected active power, and the change vector ΔQ of the injected reactive power, the voltage change of the active distribution network is calculated as follows: ΔV=RΔP+XΔQ; Let the simulation time increase by the simulation step Δt; If the simulation time t is less than the maximum simulation time t max , then return to recalculate the amount of information u(t) actually received by the actuator, otherwise end the simulation.

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