Method, device, equipment and medium for estimating disaster risk of power grid CPS

Abstract

The present invention provides a method, device, equipment and medium for estimating the disaster risk of a power grid CPS. The estimation method comprises: obtaining the probability that the information-physical system of a single load node in the power grid information-physical system has power based on the probability that the electrical network of the single load node in the power grid information-physical system has power and the dependent node information of the single load node in the power grid information-physical system; obtaining the total power loss of all load nodes in the power grid information-physical system based on the probability that the information-physical system of the single load node has power and the power supply per unit time; estimating the disaster risk data of the power grid information-physical system based on the loss data corresponding to the total power loss and the unit power loss. The technical solution of the present invention can obtain relatively accurate disaster risk data of the power grid information-physical system.

Description

Technical Field

[0001] The present invention relates to the field of power transmission technology, and in particular to a method, device, equipment and medium for estimating the disaster risk of a CPS of a power grid. Background Art

[0002] In the related art, the difference between the power grid CPS (Cyber-Physical Systems) and the ordinary power grid is that there are backup transfer lines and control devices on them. Based on this, the power grid CPS can provide a transfer path when the original power supply path fails, thereby reducing system risks.

[0003] Since the transfer requires the participation of control devices and communication networks, which often rely on the support of electrical networks, the topology and control logic of the power grid CPS are more complex than those of ordinary power grids.

[0004] Complex topology and control logic make it difficult to solve the disaster risk. The traditional method is to search all possible power supply paths for the load and regard them as independent of each other. If one of the power supply paths of the load is working normally, it is considered that the load will not lose power. The defect of this method is that all power supply paths of the load are not necessarily independent of each other. Such calculation may underestimate the probability of load power outage, resulting in inaccurate estimation of the disaster risk data of the power grid CPS. Summary of the invention

[0005] The present invention provides a method, device, electronic device and non-transient computer calibration storage medium for estimating the disaster risk of a power grid CPS, so as to solve the defect of the prior art that the disaster risk data of the power grid CPS cannot be accurately estimated, so as to obtain more accurate disaster risk data of the power grid information-physical system.

[0006] In a first aspect, the present invention provides a method for estimating the disaster risk of a power grid CPS, comprising: obtaining the probability that the information-physical system of a single load node in the power grid information-physical system has power based on the probability that the electrical network of the single load node in the power grid has power and the dependent node information of the single load node in the power grid information-physical system; obtaining the total power loss of all load nodes in the power grid information-physical system based on the probability that the information-physical system of the single load node has power and the power supply per unit time; and estimating the disaster risk data of the power grid information-physical system based on the loss data corresponding to the total power loss and the unit power loss.

[0007] According to a method for estimating disaster risk of a power grid CPS provided by the present invention, the probability of electrical network power supply of the single load node is obtained according to the disaster impact intensity suffered by the load node and the vulnerability curve of the load node to the disaster impact intensity.

[0008] According to a method for estimating the disaster risk of a power grid CPS provided by the present invention, when a single load node is configured with an energy storage device, if the cumulative amount of the power outage probability of the single load node within the first time is less than the energy storage capacity of the energy storage device, the power-on probability corresponding to the single load node is set to 1, wherein the power outage probability of the single load node is obtained based on the power outage probability of the single load node.

[0009] According to a method for estimating disaster risk of a power grid CPS provided by the present invention, obtaining the probability that the information-physical system of the single load node is powered on includes: using Newton iteration method to obtain the probability that the information-physical system of the single load node is powered on.

[0010] According to a method for estimating disaster risk of a power grid CPS provided by the present invention, the load node includes an information node, and the probability that the electrical network of the information node has power includes:

[0011]

[0012] Among them, Ω c represents the information node set in CPS, c i Indicates that node i is working normally. represents the communication dependency set of node i, represents the electrical dependency set of node i.

[0013] According to a method for estimating disaster risk of a power grid CPS provided by the present invention, the load node includes an electrical node, and the probability that the electrical network of the electrical node has electricity includes:

[0014]

[0015] Among them, Ω i represents the set of electrical nodes directly connected to node i through common electrical lines, e j→i Indicates that the normal line from node j to node i does not fail, Ω′ i represents the set of electrical nodes directly connected to node i through the transfer line, c k→i It indicates that the transfer line from node k to node i is working normally.

[0016] According to a method for estimating the disaster risk of a power grid CPS provided by the present invention, the method of obtaining the probability that the cyber-physical system of a single load node has power supply according to the probability that the electrical network of the single load node in the cyber-physical system of the power grid has power supply and the dependent node information of the single load node in the cyber-physical system of the power grid comprises:

[0017] The probability that the cyber-physical system of the single load node is electrified is obtained according to the following set of equations:

[0018]

[0019] in, Node j is the communication dependency of node i, nodes k1 and k2 are the electrical dependencies of node i, and for electrical nodes, x i =P(e i ), for information nodes, x i =P(c i ).

[0020] In a second aspect, the present invention provides a device for estimating the disaster risk of a power grid information-physical system (CPS), comprising: a power-on probability acquisition unit, for acquiring the power-on probability of the information-physical system of a single load node in the power grid information-physical system based on the power-on probability of the electrical network of the single load node in the power grid information-physical system and the dependent node information of the single load node in the power grid information-physical system; a total power loss acquisition unit, for acquiring the total power loss of all load nodes in the power grid information-physical system based on the power-on probability of the information-physical system of the single load node and the power supply per unit time; and a risk data estimation unit, for estimating the disaster risk data of the power grid information-physical system based on the loss data corresponding to the total power loss and the unit power loss.

[0021] In a third aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for estimating the disaster risk of a power grid CPS as described in any one of the above-mentioned methods are implemented.

[0022] In a fourth aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described methods for estimating the disaster risk of a power grid CPS.

[0023] The method, device, electronic device and non-transient computer calibrated storage medium for estimating the disaster risk of a power grid CPS provided by the present invention obtain the probability that the power grid CPS has power based on the probability that the electrical network of the load node has power, and based on this, realize the disaster risk data of the power grid information room system, thereby realizing the estimation of the disaster risk data of the power grid CPS. Compared with the existing technology, the accuracy of estimating the disaster risk data of the power grid CPS is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is one of the flow charts of the method for estimating the disaster risk of a power grid CPS provided by the present invention;

[0026] Figure 2 is a schematic diagram of an abstract structure of a common electrical network provided by the present invention;

[0027] Figure 3 is a schematic diagram of the abstract structure of the electrical network of the CPS provided by the present invention;

[0028] Figure 4 It is a schematic diagram of the communication network structure of the CPS provided by the present invention.

[0029] Figure 5 is a schematic diagram of the relationship between the system risk and the line failure probability provided by the present invention;

[0030] Figure 6 It is a schematic diagram of the relationship between system risk and disaster duration provided by the present invention;

[0031] Figure 7 It is a structural schematic diagram of a device for estimating disaster risk of a power grid CPS provided by the present invention;

[0032] Figure 8 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0035] like Figure 1 FIG. 1 is a flow chart of a method for estimating the disaster risk of a power grid CPS according to an embodiment of the present invention. The method provided by the embodiment of the present invention can be executed by any electronic device with computer processing capabilities, such as a terminal device and / or a server. Figure 1 As shown in Figure 1, the estimation method of the disaster risk of the power grid CPS includes:

[0036] Step 102 , based on the probability that the electrical network of a single load node in the power grid power grid network physical system is powered and the dependent node information of the single load node in the power grid power grid network physical system, obtain the probability that the network physical system of a single load node is powered.

[0037] Step 104, obtaining the total power loss of all load nodes in the cyber-physical system of the power grid according to the probability of power supply of the cyber-physical system of a single load node and the power supply per unit time;

[0038] Step 106, estimating the disaster risk data of the power grid cyber-physical system based on the loss data corresponding to the total power loss and the unit power loss.

[0039] In the embodiment of the present invention, the power grid CPS may be referred to as CPS for short.

[0040] The technical solution of the present invention involves the disaster risk and outage risk of the power grid CPS under natural disasters, that is, given the disaster model and parameters, the model and parameters of the power grid CPS, solving the outage risk of the power grid CPS under the disaster. Since the CPS has a spare transfer line and the control device on it, it is very difficult to estimate the disaster risk of the CPS.

[0041] The technical solution of the present invention can take into account the influence of the backup transfer routes and control devices of the CPS by analyzing the probability of the electrical network of a single load node in the power grid CPS and the dependent node information of the single load node in the power grid information-physical system, thereby more accurately obtaining the probability of the information-physical system of the single load node being powered, and ultimately obtaining more accurate disaster risk data of the CPS.

[0042] In the technical solution of the present invention, the probability that the electrical network of the single load node is electrified is obtained based on the disaster impact intensity suffered by the load node and the vulnerability curve of the load node to the disaster impact intensity.

[0043] The power grid is subject to a variety of natural disasters, such as typhoons, frost, floods, etc. The disasters themselves and the mechanisms of power grid disasters are very complex. Here we can simply assume that each disaster will last for a certain period of time, and this period is discretized into a finite number of moments [t0, t n ], assuming that the intervals between each moment are the same, Δt, then [t0,t n ] can also be simply regarded as the moment number of [0,n]. The following does not distinguish between the concepts of "moment" and "moment number". At each moment, the power grid equipment set Ω e Each device in the system will be subject to a specific disaster impact intensity, defined by the formula:

[0044]

[0045] is the disaster impact intensity of device i at time t. If the geographical distribution scale of the power grid is not too large, it can be assumed that all devices in the power grid are subject to the same disaster impact intensity, that is, d t ,t∈[t0,t n ].

[0046] Lines and other equipment in the power grid may fail under the impact of disasters. Assume that the equipment in the power grid is only impacted by a typical disaster, and assume that the disaster intensity of equipment i at time t is The failure rate of equipment affected by disasters can be given by the vulnerability curve of the equipment to the disaster impact. Here, the vulnerability curve of the equipment to the disaster impact can be obtained based on the design strength and experiments. Definition formula:

[0047]

[0048] is the failure rate of the disaster impact on equipment i at time t, where φ i is the functional form of the vulnerability curve of device i to the typical disaster impact. By analyzing a single moment, the failure probability of device i at that moment can be obtained as follows:

[0049]

[0050] in, represents the failure of device i. In formula (3), it is assumed that device i has not failed until time t-1. That is, the above formula actually represents the probability of failure of device i between time t-1 and time t. At the same time, it is assumed that the failure rate of device i between time t-1 and time t is If the accumulation effect over time is considered, the probability that device i will not fail until that moment is:

[0051]

[0052] where e i = means that device i does not fail. Formula (4) means that device i has not failed until time t-1, and has not failed between time t-1 and time t. Therefore, device i has not failed until time t. It can be assumed that all devices will not fail at the beginning of the disaster, that is,

[0053] P0(e i )=1,i∈Ω e

[0054] It should be noted that once the disaster intensity of the equipment is given, the disaster failures of multiple equipment become independent random events, and the corresponding failure probabilities are also independent of each other.

[0055] Generally, it can be considered that there are only four types of equipment in the power grid: power supply, busbar, line and load. The power supply and load are connected to the busbar, and the busbars are connected to each other through the line. Without considering the fault of the busbar itself, the power supply can be considered to have high reliability. Whether it works normally or not has nothing to do with the status of the surrounding nodes, while whether the load node has power depends on the power supply status of the surrounding nodes; the failure probability of the line is only determined by the disaster impact and the fragility curve. The line may be shut down after being impacted by a disaster, resulting in power loss of the busbar, and further causing power outage of the load.

[0056] like Figure 2 Shown is a schematic diagram of the abstract structure of a common electrical network.

[0057] Specifically, Figure 2 As shown, the bus 212 can be abstracted as a node, the line can be abstracted as an edge, and the power grid is a graph structure composed of nodes and edges. Since the bus may connect the power source 211 and the load 213 and load 214, the nodes in the power grid can also be simply divided into two categories: high-reliability power node 221, ordinary load node 222, ordinary load node 223, and ordinary load node 224. The probability of power supply node being powered can be simply considered as the formula:

[0058] P r (e i )=1,i∈Ω s ,t∈[t0,t n ] (5)

[0059] Where Ω s Indicates a power device set. Figure 2 In, P t (e1) = 1. Ordinary load nodes need to be powered by surrounding nodes through lines. Assuming that all lines can supply power in both directions, the probability that ordinary load nodes have power is as follows:

[0060]

[0061] Among them, Ω l represents the common load node set, Ω i represents the set of neighboring nodes of node i, that is, the nodes directly connected to node i, e j→i It means that there is no fault on the line from node j to node i.

[0062] by Figure 1 Taking the middle node 2, i.e. the load node 222, as an example, there is a formula:

[0063] P t(e2) = 1-∏ j＝1,3,4 (1-P t (e j )·P t (e j→i )) (7)

[0064] Note that the above formula only contains the probability value at time t, and each time can be solved separately, that is, for each time, it can be simplified to formula (8) or (9):

[0065]

[0066]

[0067] Among them, P(e j→i ) is obtained by solving the equipment failure probability model under disasters and can be considered as a known quantity. Therefore, the above equation is an equation for the probability of a node being powered on. Let x i =P(e i ), the equations of all nodes are as follows:

[0068]

[0069] The total number of equations is equal to the number of unknowns, that is, the number of all nodes. Considering the Newton method for iterative solution, the Jacobian matrix J can be written, where For power node i∈Ω s There is a formula:

[0070]

[0071] For the load node (i∈Ω l ) has the formula:

[0072]

[0073] The nth step iteration formula is:

[0074] x (n+1) =x (n) -J -1 ·f (n) (13)

[0075] By iterating repeatedly until the convergence condition is reached, the probability P of each load node in the power grid at each moment can be obtained. t (e i ),i∈Ω l ,t∈[t1,t n ]. Among them, the time t0 does not need to be solved, P0(e i )=1. It can be seen that the failure probability of each node is

[0076] like Figure 3 The diagram shows the abstract structure of the electrical network of the CPS. Figure 3 As shown, power sources 311 and 314 can be abstracted into power source nodes 321 and 324, respectively. Busbar 312, busbar 315 and load 313 can be abstracted into load nodes 322, 325 and 323, respectively. Tie switch 316 can be abstracted into information node 326.

[0077] like Figure 3 As shown, in addition to the above-mentioned electrical nodes and lines, a FTU (Feeder Terminal Unit) 317 is placed at each electrical node in the CPS for measuring the node status. In addition, there is a transfer line in the CPS, and an FTU for measurement and control is also placed at the connecting switch on it. All FTUs need to be connected to a switch somewhere to connect to the control center through a layered communication network, thereby realizing CPS optimization scheduling. Here, the overall control logic of the CPS can be ignored, and only the connectivity of the network is considered, that is, whether the transfer line can work normally.

[0078] In related technologies, in order to ensure the security and reliability of the communication network, the structure of the communication network in the CPS is usually designed as a layered structure. The bottom layer of the layered structure is called the access layer, which is usually composed of several switches and directly connects the end users through physical lines, such as all FTUs in the CPS. The middle layer of the layered structure is called the aggregation layer, which is usually composed of several switches and routers, connecting the access layer switches within a certain range and aggregating the information in the area. The top layer of the layered structure is called the core layer, which connects the equipment in the aggregation layer and provides a communication channel with the CPS control center.

[0079] The structure of the communication network in CPS is as follows Figure 4 As shown, the communication network includes power source 411 , power source 414 , power source 421 , power source 424 , bus 412 , bus 415 , bus 422 , bus 425 , load 413 , load 423 , tie switch 416 and tie switch 426 .

[0080] like Figure 4 The CPS shown has only one access layer switch 430. Since the aggregation layer and core layer have exceeded the scope of CPS construction, or their reliability and operation performance are relatively good, the impact of this part of the communication network on the CPS will not be considered below.

[0081] Like ordinary lines, the electrical nodes at both ends of the transfer line have a certain probability of failure under the impact of disasters, which can be calculated by the equipment failure probability model under disasters. In addition, the normal operation of the transfer line also requires the normal operation of the contact switch on it. The contact switch is modeled as a new type of node, called an information node. The information node is a comprehensive node of electricity and communication. The normal operation of the information node requires two types of dependencies. One is electrical dependency, and the other is communication dependency. The electrical dependency refers to the electrical nodes at both ends of the transfer line where the information node is located, and the communication dependency refers to the switch connected to the information node FTU.

[0082] Among them, the probability formula for the normal operation of the information node is:

[0083]

[0084] Among them, Ω c represents the information node set in CPS, c i Indicates that information node i is working normally. represents the communication dependency set of information node i, represents the electrical dependency set of information node i. In general There is only one node in the network, namely the electrical node where the switch connected to the information node FTU is located. There are only two nodes in the equation, namely the electrical nodes at both ends of the transfer line where the information node is located, and the corresponding formula is:

[0085]

[0086] in,

[0087] by Figure 3 Taking the CPS in as an example, the electrical dependency of information node 6 is the electrical nodes 2 and 5 on both sides, and the communication dependency depends on the position of the switch connected to the FTU at node 6.

[0088] Then the formula:

[0089] P t (c6) = P t (e2)·(1-(1-P t (e2))·(1-P t (e5))) (16)

[0090] Here, P appears in the formula t (e2)·(1-P t (e2)), logically this term should be 0, that is, P t (c6) = P t (e2).

[0091] In fact, the reason for this logical paradox is that That is, the electrical dependence and communication dependence of information node i overlap. For this situation, special treatment can be performed, that is, The following assumes that this situation does not exist in the system. Also note that the above formula only contains the probability value at time t, and each time can be solved separately, that is, for each time, it can be simplified as

[0092]

[0093] in, The above formula is the probability that the information node in CPS has power. It can be seen that the probability that the information node has power is only related to the probability that the specific electrical node has power, and can be added to the equation group of the electrical network disaster model.

[0094] At the same time, it is noted that due to the existence of the transfer line, the probability of the electrical node having electricity may change.

[0095]

[0096] Where Ω i represents the set of electrical nodes directly connected to node i through common electrical lines, e j→i Indicates that the normal line from node j to node i does not fail, Ω′ i represents the set of electrical nodes directly connected to node i through the transfer line, c k→i It means that the transfer line from node k to node i works normally, so

[0097] P(c k→i )=P(e k→i )·P(c w ),w∈Ω k,i

[0098] w∈Ω k,i Indicates that the information node w is on the transfer line k→i. For nodes not connected to the transfer line, Ω′ i Is empty, there is no second product. In summary, the expression formula for the probability of power on the load node can be written as:

[0099]

[0100] Where P(e j→i ) and P(e k→i ) can be considered to be known, then the above formula only contains the probability that the electrical node and the information node have electricity, Figure 3 Taking node 2 in the CPS shown as an example, there is a formula:

[0101] P(e2)=1-∏ j＝1,3 (1-P(e j)·P(e j→i ))·(1-P(e5)·P(e 5→2 )·P(c6)) (20)

[0102] Number the two types of nodes the same, and let x i =P(e i ), let x i =P(c i ), the equations for the probability of disaster failure in CPS are as follows:

[0103]

[0104] The third kind of equation It means that node j is the communication dependency of node i, and nodes k1 and k2 are the electrical dependencies of node i.

[0105] In the embodiment of the present invention, the Newton iteration method may be used to obtain the probability that the cyber-physical system of the single load node is electrically charged.

[0106] In order to use Newton's method to iteratively solve, the Jacobian matrix elements of the above three types of nodes are analyzed, and the power node (i∈Ω s ) still has the formula:

[0107]

[0108] For the load node (i∈Ω l ) has the formula:

[0109]

[0110] in, Indicates that information node j is not on any transfer line connected to node i; j∈Ω′ i ,w∈Ω i,j Indicates that node j is connected to node i through a transfer line, and information node w is the tie switch on the transfer line; j∈Ω i,k ,k∈Ω′ i It means that node k is connected to node i through a transfer line, and information node j is the tie switch on the transfer line.

[0111] For information nodes (i∈Ω c ) has the formula:

[0112]

[0113] From the above formula, it can be seen that the probability of an information node being powered usually depends only on the other three nodes, namely one communication-dependent node and two electrical-dependent nodes. So far, the probability model of CPS disaster failure is given. The probability of each load node being powered at each time in the power grid can be obtained by iterative solution using the Newton method. t (e i ),i∈Ω l ,t∈[t1,t n ], then the failure probability of each node is

[0114] The normal operation of the CPS transfer path depends on the tie switch on it, and the normal operation of the tie switch requires the support of the communication network. In order to enable the communication network to have a certain degree of independent survival ability when the electrical network is damaged, energy storage is usually configured at important communication nodes. Specifically, the location of the switch connected to the FTU of the tie switch is more important. Figure 3 In the CPS shown, energy storage will be configured at node 2 so that when node 2 is affected by a disaster and stops operating, the switch there can still operate normally.

[0115] It can be seen that the energy storage in CPS will be used to ensure the normal operation of the access layer switch, that is, to ensure that the communication dependencies of the information node can work normally. If the energy storage can play a role at time t, the probability of information node i having power will increase.

[0116] However, energy storage does not always work because the capacity of energy storage is limited, and there is always a certain probability that nodes will fail and consume energy storage during the duration of the disaster. Here, energy storage is for specific devices such as switches, and its output power can be considered constant. The following does not distinguish between the concepts of "energy storage capacity" and "energy storage duration".

[0117] Assume that electrical node j is the communication dependency of information node i, that is And a duration of T is placed at node j. j Energy storage, then the necessary and sufficient condition for energy storage to still work at time t is that from the beginning of the disaster to time t, the sum of the failure probabilities of node j is less than the total energy storage duration. This is because if a node is affected by a disaster and loses power, it needs to consume one unit of energy storage in one unit of time. Therefore, the probability of node failure is the expected value of energy storage consumption. When the expected value has not yet reached the total energy storage duration, it can be considered that the energy storage can still work normally. Therefore, due to the existence of energy storage, the information node equation in the CPS disaster failure probability model can be expressed as:

[0118]

[0119] in, The necessary and sufficient condition for energy storage to still play a role at time t is

[0120]

[0121] For the solution process of the entire CPS system, we can first assume that there is no energy storage, solve the equations at each moment during the disaster duration to obtain the failure probability of each node, and then judge whether the expected energy storage consumption, that is, the cumulative sum of the failure probability, reaches the upper limit for the important nodes equipped with energy storage. Assuming that there is The equation group before and at time t is rewritten according to the above formula, and the equation group after time t remains unchanged. Thus, the power failure probability of each load node of the CPS system at each moment during the disaster duration can be obtained.

[0122] In summary, when a single load node is configured with an energy storage device, if the cumulative amount of the power outage probability of the single load node within the first time is less than the energy storage capacity of the energy storage device, the power-on probability corresponding to the single load node is set to 1, wherein the power outage probability of the single load node is obtained based on the power outage probability of the single load node.

[0123] The above gives a complete CPS disaster failure probability model, which can solve the power failure probability of each load node in the system at each time within the disaster duration. Assuming that The risk of system disasters also needs to be given.

[0124] Without considering the role of emergency repair and restoration during disasters, it is assumed that t n At the moment when the impact of the disaster completely disappears, the fault caused by the disaster is repaired, and the system resumes normal power supply, let the power supply of load node i in the unit time interval Δt be W i If load node i loses power between time t-1 and time t, the power loss of node i in this disaster is W i ·(t n -t+1), and the probability of power failure at node i at time t is The probability of a node losing power at time t-1 is Therefore, the expected power loss of node i in this disaster is:

[0125]

[0126] Assume that the loss caused by the unit power loss of node i is C i , the sum of the losses of all load nodes is the CPS disaster risk, and its formula is:

[0127]

[0128] again Further calculation of the above formula can get a more concise expression:

[0129]

[0130] That is, it is only necessary to accumulate the probability of power outage at each time and then multiply it by the power outage loss per unit time.

[0131] In one embodiment of the present invention, the CPS is composed of 62 electrical nodes, including three independent power supply areas, each area is interconnected through a transfer line and a contact switch, and there are 6 transfer lines and corresponding contact switches in the system. The communication topology of the system is organized according to the hierarchy of FTU / DTU (Data Transfer Unit)-access layer switch-aggregation layer-core layer-server, and the communication network can also only focus on the access layer switch.

[0132] From the CPS disaster risk model, we can see that the system risk is mainly related to three factors: network topology, line failure probability and disaster duration. When the network topology is given, we first consider the system risk within a unit time. To simplify the problem, we assume that the switch connected to the tie switch FTU can always work normally, that is, the communication dependency in the system will not fail; at the same time, we assume that the failure probability of the transfer line is the same as that of the ordinary line; in addition, we can ignore the solution process from the disaster and equipment vulnerability curve to the equipment failure probability, and directly study the relationship between system risk and line failure probability.

[0133] When the line failure probability changes from 0 to 1, that is, the line goes from being unlikely to fail to being certain to fail, the system risk changes as follows: Figure 5 As shown in the curve 502 in FIG. 1 , it can be seen that when the line does not fail, the system loss is 0, because the model assumes that only line failure can cause load power outage; when the line must fail, the system loss will be the load at full load, that is, all loads will lose power. Here, it is assumed that the loss per unit power outage is 1.

[0134] If there is no transfer line in the system, such as Figure 5 As shown by curve 501 in , the overall system risk will be higher than when there is a transfer line. However, since it is assumed here that the transfer line has the same failure probability as the ordinary line, even if there is a transfer line, when the failure probability is close to 1, the transfer line will not be able to function and the system will still lose almost all loads.

[0135] Consider reinforcing the transfer line so that its failure probability is half of that of the ordinary line. Figure 5 As shown in the middle curve 503, the system risk is generally lower than when it is not reinforced, especially when the line failure probability is high, that is, when the disaster intensity is high. Note that when the ordinary line failure probability is 1, the reinforcement of the transfer path will not lose all loads, because there are transfer lines that connect some loads directly to the power source.

[0136] The above results show that when there is a probability of disaster failure in the power grid line, it is necessary to reduce the risk of system outage by transferring the supply line. This effect is relatively obvious when the probability of line failure is not too large. When the disaster intensity is large and the probability of line failure is large, it is necessary to strengthen the disaster resistance level of the transfer line to play a practical role.

[0137] Since system risk is the accumulation of power loss over time, system risk will inevitably increase as the duration of the disaster increases.

[0138] According to the probability expression of equipment not failing after being damaged:

[0139]

[0140] It can be seen that under the condition of equal time intervals, the probability of equipment being powered on decays exponentially with time. Therefore, when the disaster lasts for a long time, the system risk will increase rapidly. Figure 6 As shown in , the line failure probability per unit time is assumed to be 0.1. Figure 6 As shown, curve 601 represents the absence of a transfer path, curve 602 represents the existence of a transfer path, and curve 603 represents the reinforcement of the transfer path. In addition, as the duration of the disaster increases, the role of the transfer path becomes more obvious. When the power grid in a certain area is often hit by long-term disasters, the construction of transfer lines becomes more necessary.

[0141] In the technical solution of the present invention, the probability of CPS shutdown due to disasters is solved according to a group of nonlinear equations. First, a disaster model and a probability model of equipment failure under disasters are given. Then, a probability model of disaster shutdown failures is given for ordinary distribution networks, and then it is further expanded to the probability of CPS shutdown due to disasters and a risk model.

[0142] The method for estimating the disaster risk of the power grid CPS of the embodiment of the present invention obtains the probability that the power grid CPS has power based on the probability that the electrical network of the load node has power, and based on this, realizes the disaster risk data of the power grid information room system, thereby realizing the estimation of the disaster risk data of the power grid CPS. Compared with the existing technology, the accuracy of estimating the disaster risk data of the power grid CPS is higher.

[0143] The following is a description of the disaster risk estimation device for a power grid CPS provided by the present invention. The disaster risk estimation device for a power grid CPS described below and the disaster risk estimation method for a power grid CPS described above can be referred to each other.

[0144] like Figure 7 As shown, the device for estimating the disaster risk of a power grid CPS provided by an embodiment of the present invention includes:

[0145] A power-on probability acquisition unit 702 is used to acquire the power-on probability of the cyber-physical system of a single load node according to the power-on probability of the electrical network of the single load node in the cyber-physical system of the power grid and the dependent node information of the single load node in the cyber-physical system of the power grid;

[0146] A total power loss acquisition unit 704 is used to acquire the total power loss of all load nodes in the power grid cyber-physical system according to the probability of power supply of the cyber-physical system of the single load node and the power supply per unit time;

[0147] The risk data estimating unit 706 is used to estimate the disaster risk data of the power grid cyber-physical system according to the loss data corresponding to the total power loss and the unit power loss.

[0148] It can be understood that the above-mentioned device for estimating the disaster risk of the power grid CPS can implement the various steps of the method for estimating the disaster risk of the power grid CPS provided in the aforementioned embodiment, and the relevant explanations on the method for estimating the disaster risk of the power grid CPS are all applicable to the device for estimating the disaster risk of the power grid CPS, which will not be repeated here.

[0149] The device for estimating the disaster risk of the power grid CPS of the embodiment of the present invention obtains the probability that the power grid CPS has power based on the probability that the electrical network of the load node has power, and realizes the disaster risk data of the power grid information room system based on this, thereby realizing the estimation of the disaster risk data of the power grid CPS. Compared with the existing technology, the accuracy of estimating the disaster risk data of the power grid CPS is higher.

[0150] Figure 8 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 8 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the method for estimating the disaster risk of the power grid CPS, the method comprising: obtaining the probability of power supply of the information-physical system of the single load node in the power grid information-physical system according to the probability of power supply of the electrical network of the single load node in the power grid information-physical system and the dependent node information of the single load node in the power grid information-physical system; obtaining the total power loss of all load nodes in the power grid information-physical system according to the probability of power supply of the information-physical system of the single load node and the power supply per unit time; estimating the disaster risk data of the power grid information-physical system according to the loss data corresponding to the total power loss and the unit power loss.

[0151] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0152] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the disaster risk estimation method of the power grid CPS provided by the above-mentioned methods, and the method includes: obtaining the probability that the information-physical system of a single load node in the power grid information-physical system has power based on the probability that the electrical network of the single load node in the power grid information-physical system has power and the dependent node information of the single load node in the power grid information-physical system; obtaining the total power loss of all load nodes in the power grid information-physical system based on the probability that the information-physical system of the single load node has power and the power supply per unit time; and estimating the disaster risk data of the power grid information-physical system based on the loss data corresponding to the total power loss and the unit power loss.

[0153] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the above-mentioned methods for estimating the disaster risk of the power grid CPS, the method comprising: obtaining the probability that the information-physical system of a single load node in the power grid information-physical system has power based on the probability that the electrical network of the single load node in the power grid information-physical system has power and the dependent node information of the single load node in the power grid information-physical system; obtaining the total power loss of all load nodes in the power grid information-physical system based on the probability that the information-physical system of the single load node has power and the power supply per unit time; and estimating the disaster risk data of the power grid information-physical system based on the loss data corresponding to the total power loss and the unit power loss.

[0154] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0155] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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. However, 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 embodiments of the present invention.

Claims

1. A method for estimating the disaster risk of a power grid cyber-physical system (CPS). It is characterized in that include: According to the probability that the electrical network of a single load node in the power grid cyber-physical system is powered and the dependent node information of the single load node in the power grid cyber-physical system, the probability that the cyber-physical system of the single load node is powered is obtained; Obtaining the total power loss of all load nodes in the power grid cyber-physical system according to the probability of power being available in the cyber-physical system of the single load node and the power supply per unit time; Estimate disaster risk data of the power grid cyber-physical system according to the loss data corresponding to the total power loss and the unit power loss; The probability that the electrical network of the single load node is powered is obtained based on the disaster impact intensity suffered by the load node and the vulnerability curve of the load node to the disaster impact intensity; Wherein, when a single load node is configured with an energy storage device, if the cumulative amount of the power failure probability of the single load node within the first time is less than the energy storage capacity of the energy storage device, the power-on probability corresponding to the single load node is set to 1, wherein the power failure probability of the single load node is obtained according to the power failure probability of the single load node; Wherein, the load node includes an information node, and the probability that the electrical network of the information node is powered is: Among them, Ω c represents the information node set in CPS, c i Indicates that node i is working normally. represents the communication dependency set of node i, represents the electrical dependency set of node i; Wherein, the load node includes an electrical node, and the probability that the electrical network of the electrical node has electricity is: Among them, Ω i represents the set of electrical nodes directly connected to node i through common electrical lines, e j→i Indicates that the common line from node j to node i does not fail, Ω i ′ represents the set of electrical nodes directly connected to node i through the transfer line, c k→i It indicates that the transfer line from node k to node i is working normally; Wherein, obtaining the probability that the cyber-physical system of a single load node is powered on according to the probability that the electrical network of the single load node in the cyber-physical system of the power grid is powered on and the dependent node information of the single load node in the cyber-physical system of the power grid comprises: The Newton iteration method is used to solve the following formula to obtain the probability that the cyber-physical system of the single load node is electrified: in, Node j is the communication dependency of node i, and node k 1 and k 2 is the electrical dependency of node i. For an electrical node, x i =P(e i ), for information nodes, x i =P(c i ).

2. A device for estimating the disaster risk of a power grid cyber-physical system (CPS); It is characterized in that include: A power-on probability acquisition unit, configured to acquire the power-on probability of the cyber-physical system of a single load node according to the power-on probability of the electrical network of the single load node in the cyber-physical system of the power grid and the dependent node information of the single load node in the cyber-physical system of the power grid; A total power loss acquisition unit, used to acquire the total power loss of all load nodes in the power grid cyber-physical system according to the probability of power supply in the cyber-physical system of the single load node and the power supply per unit time; A risk data estimation unit, configured to estimate the disaster risk data of the power grid cyber-physical system according to the loss data corresponding to the total power loss and the unit power loss; The probability that the electrical network of the single load node is powered is obtained based on the disaster impact intensity suffered by the load node and the vulnerability curve of the load node to the disaster impact intensity; Wherein, when a single load node is configured with an energy storage device, if the cumulative amount of the power failure probability of the single load node within the first time is less than the energy storage capacity of the energy storage device, the power-on probability corresponding to the single load node is set to 1, wherein the power failure probability of the single load node is obtained according to the power failure probability of the single load node; Wherein, the load node includes an information node, and the probability that the electrical network of the information node is powered is: Among them, Ω c represents the information node set in CPS, c i Indicates that node i is working normally. represents the communication dependency set of node i, represents the electrical dependency set of node i; Wherein, the load node includes an electrical node, and the probability that the electrical network of the electrical node has electricity is: Among them, Ω i represents the set of electrical nodes directly connected to node i through common electrical lines, e j→i Indicates that the common line from node j to node i does not fail, Ω i ′ represents the set of electrical nodes directly connected to node i through the transfer line, c k→i It indicates that the transfer line from node k to node i is working normally; Wherein, obtaining the probability that the cyber-physical system of a single load node is powered on according to the probability that the electrical network of the single load node in the cyber-physical system of the power grid is powered on and the dependent node information of the single load node in the cyber-physical system of the power grid comprises: The Newton iteration method is used to solve the following formula to obtain the probability that the cyber-physical system of the single load node is electrified: in, Node j is the communication dependency of node i, and node k 1 and k 2 is the electrical dependency of node i. For an electrical node, x i =P(e i ), for information nodes, x i =P(c i ).

3. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, It is characterized in that When the processor executes the program, the steps of the method for estimating the disaster risk of the power grid cyber-physical system CPS as described in claim 1 are implemented.

4. A non-transitory computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the steps of the method for estimating the disaster risk of the power grid cyber-physical system CPS as claimed in claim 1 are implemented.

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