Node recovery importance expected value evaluation method, system and device and medium

Abstract

The invention belongs to the technical field of power systems, and discloses a node recovery importance degree expected value evaluation method, system and device and a medium, and the method comprises the steps: obtaining power grid operation information and a power transmission line fault probability evaluation result, and initializing the overall calculation parameters of sampling simulation and the calculation parameters of this round based on the power transmission line fault probability evaluation result; through iterative sampling of sampling simulation of recoverable states, power grid states of power transmission lines and nodes at all time points are identified in sequence, the power transmission lines and the nodes which do not meet recoverable requirements in sampling results of each round are removed, and the importance degree of the reserved power transmission lines and the reserved nodes is calculated; sampling results after all iteration rounds are finished are integrated, and based on the importance degrees of the power transmission lines and the nodes, importance degree indexes and operation time expected values of the damaged power transmission lines and the nodes are calculated. According to the method, through dynamic evaluation and online updating of the node importance degree considering the influence of disaster uncertainty, the identification capability of key nodes and lines of a power grid in a recovery state is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method, system, device and medium for evaluating expected values ​​of node recovery importance. Background Art

[0002] The purpose of power grid restoration control after a major power outage is to quickly, safely, and economically restore power supply and avoid introducing new safety and stability risks. To this end, during the power grid restoration process, it is necessary to dynamically analyze the key nodes to be restored according to the changes in power grid conditions and external disasters, build a reasonable transition power grid containing key nodes, gradually expand the available restoration power and restoration range, and provide decision support for dispatching and operation personnel.

[0003] Most existing studies analyze the importance of nodes and lines from the perspective of the topological characteristics of the power network and optimize the skeleton network. Among them, node importance is a key indicator for optimizing restoration decisions. Currently, node contraction method, betweenness method, and deletion method are mostly used to evaluate the topological importance of nodes from a global perspective; the paper "Two-layer Optimization Strategy for Network Reconstruction Based on Node Importance Evaluation Matrix" further introduces an importance evaluation matrix to comprehensively consider the global importance of nodes and local factors such as the influence of adjacent nodes. For power generation nodes, the technical parameters of the units are comprehensively considered to determine their startup priority. Different from the above-mentioned deterministic indicators, the paper "Skeleton Network Reconstruction Based on Node Recovery Reliability" proposes a node recovery reliability indicator as the basis for node recovery. The paper "Identification of Critical Lines in Transmission Network Grid Restoration Schemes" defines a relative line betweenness indicator to characterize the availability of the line, and proposes a line importance indicator based on the impact of line commissioning failure on the restoration scheme.

[0004] At present, the research on safe and stable defense technology for disaster response mainly focuses on the fault probability assessment of disaster-induced lines, the expected fault set and control measures set considering the fault probability, etc. The current research schemes are difficult to fully reflect the expected recovery benefits of nodes, and have not yet involved the impact of disaster factors on node importance assessment and target grid optimization.

[0005] Therefore, how to provide a method, system, device and medium for evaluating the expected value of node recovery importance is a problem that needs to be solved urgently. Summary of the invention

[0006] The embodiments of the present invention provide a method, system, device and medium for evaluating the expected value of node recovery importance to solve the above-mentioned technical problems existing in the prior art.

[0007] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be a general review, nor is it intended to identify key / important components or to delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0008] According to a first aspect of an embodiment of the present invention, a method for evaluating an expected value of node recovery importance is provided.

[0009] In one embodiment, the node recovery importance expected value evaluation method includes:

[0010] Obtaining grid operation information and transmission line fault probability assessment results, and initializing overall calculation parameters and current round calculation parameters of sampling simulation based on the transmission line fault probability assessment results;

[0011] Through iterative sampling of restorable state sampling simulation, the power grid status of transmission lines and nodes at each time point is identified in turn, the transmission lines and nodes that do not meet the restorable requirements in each round of sampling results are eliminated, and the importance of the retained transmission lines and nodes is calculated;

[0012] The sampling results after all iterations are integrated, and based on the importance of transmission lines and nodes, the importance index and expected operation time of damaged transmission lines and nodes are calculated.

[0013] In one embodiment, the obtaining of the grid operation information and the transmission line fault probability assessment result, and initializing the overall calculation parameters and the current round calculation parameters of the sampling simulation based on the transmission line fault probability assessment result, include:

[0014] Collecting grid operation information, and using online evaluation software to generate transmission line failure probability evaluation results based on the time scale of external disaster evolution, wherein the transmission line failure probability evaluation results include single failure probability evaluation results and group failure probability evaluation results;

[0015] Based on the transmission line fault probability assessment result, the recoverable state and the irrecoverable state of the lines and nodes in the power grid are defined, and the overall calculation parameters of the sampling simulation of the recoverable state and the calculation parameters of the current round when starting iterative sampling are initialized.

[0016] In one embodiment, the nodes include power generation nodes and non-power generation nodes; the overall calculation parameters include the total number of sampling simulation rounds, the number of sampling simulation rounds, the initial value of the number of times the sampling simulation results of each line are in an irrecoverable state, the initial value of the number of times the sampling simulation results of each node are in an irrecoverable state, and the total evaluation period and time point.

[0017] In one embodiment, the iterative sampling of the sampling simulation of the recoverable state sequentially identifies the grid state of the transmission lines and nodes at each time point, removes the transmission lines and nodes that do not meet the recoverable requirements in each round of sampling results, and calculates the importance of the retained transmission lines and nodes, including:

[0018] Set the time point of this round of sampling simulation, identify the recoverable and irrecoverable states of each line in the power grid by sampling line by line, calculate the operation time of the sampled lines, and analyze the recoverable and irrecoverable states of each group by integrating the random sampling values ​​of the constituent lines in the group;

[0019] Remove the lines and nodes with irrecoverable status in the sampling results, and then remove the isolated nodes and local passive networks, and record the grid status after this round of sampling simulation and removal; and based on the grid status of this round of sampling simulation, calculate the importance of power generation nodes, non-power generation nodes and lines respectively;

[0020] If the current sampling time point is less than the sampling time point number, the number of iterations is increased by one, and the sampling of each line is returned to continue iteration, otherwise it goes to the next step;

[0021] If the number of sampling simulation rounds is less than the preset maximum number of sampling simulation iterations, the number of iterations is increased by one, and the process returns to the initialization of the calculation parameters for this round and continues to iterate, otherwise it proceeds to the next step.

[0022] In one embodiment, the time point of setting the current round of sampling simulation is to identify the recoverable state and the irrecoverable state of each line in the power grid by sampling line by line, and then calculate the operation time of the sampled line, and analyze the recoverable state and the irrecoverable state of each group by integrating the random sampling values ​​of the constituent lines in the group. The method includes:

[0023] The single fault probability of each line is sampled at that time point. Any line to be tested is selected. If the sampling random number is less than the single fault probability of the line to be tested, the line to be tested is judged to have a permanent fault and marked as an unrecoverable state. Otherwise, it is marked as a recoverable state. Based on the switch operation time opening rate distribution, the operation time of the line to be tested is sampled;

[0024] Comb the constituent lines of the cluster in the power grid, calculate the product of the random sampling values ​​of the constituent lines in each cluster, and if the product value is less than the cluster failure probability of the cluster, it is determined that the cluster has a cluster failure and is marked as an unrecoverable state. Otherwise, it is marked as a recoverable state.

[0025] In one embodiment, the formula for calculating the importance of power generation nodes, non-power generation nodes and lines includes:

[0026]

[0027] In the formula, Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Indicates the importance of the line; ω1 and ω2 represent weight values; represents the normalized node betweenness; I′ G,m I′ represents the expected revenue of the power generation node after normalization; B,m represents the expected revenue of non-generation nodes after normalization; represents the betweenness of the kth line under the current power grid status; Indicates the number of shortest paths between nodes s and t in the current power grid state; represents the number of shortest paths between nodes s and t passing through line k; V represents the set of nodes in the network; m represents a node.

[0028] In one embodiment, the formula for calculating the importance index and expected operation time of the damaged transmission line and node includes:

[0029]

[0030] In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; N t represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

[0031] According to a second aspect of an embodiment of the present invention, a node recovery importance expected value evaluation system is provided.

[0032] In one embodiment, the node recovery importance expected value evaluation system includes:

[0033] An initialization module is used to obtain power grid operation information and transmission line fault probability assessment results, and initialize the overall calculation parameters of the sampling simulation and the current round of calculation parameters based on the transmission line fault probability assessment results;

[0034] The sampling simulation module is used to identify the grid status of the transmission lines and nodes at each time point in turn through iterative sampling of the sampling simulation of the recoverable state, eliminate the transmission lines and nodes that do not meet the recoverable requirements in each round of sampling results, and calculate the importance of the retained transmission lines and nodes;

[0035] The calculation and evaluation module is used to integrate the sampling results after all iteration rounds, and calculate the importance index and expected operation time of the damaged transmission lines and nodes based on the importance of the transmission lines and nodes.

[0036] In one embodiment, the initialization module includes: a data acquisition module and a parameter setting module, wherein:

[0037] The data acquisition module is used to collect power grid operation information, and based on the time scale of external disaster evolution, generates a transmission line fault probability assessment result using online assessment software, and the transmission line fault probability assessment result includes a single fault probability assessment result and a group fault probability assessment result;

[0038] The parameter setting module is used to define the recoverable and irrecoverable states of the lines and nodes in the power grid based on the transmission line fault probability assessment result, and initialize and set the overall calculation parameters of the sampling simulation of the recoverable state, as well as the current round of calculation parameters when starting iterative sampling.

[0039] In one embodiment, the nodes include power generation nodes and non-power generation nodes; the overall calculation parameters include the total number of sampling simulation rounds, the number of sampling simulation rounds, the initial value of the number of times the sampling simulation results of each line are in an irrecoverable state, the initial value of the number of times the sampling simulation results of each node are in an irrecoverable state, and the total evaluation period and time point.

[0040] In one embodiment, the sampling simulation module includes: a state analysis module, an importance calculation module, a time point iteration module and a round number iteration module, wherein:

[0041] The state analysis module is used to set the time point of this round of sampling simulation, identify the recoverable state and irrecoverable state of each line in the power grid by sampling line by line, calculate the operation time of the sampled line, and analyze the recoverable state and irrecoverable state of each group by integrating the random sampling values ​​of the constituent lines in the group;

[0042] The importance calculation module is used to remove the lines and nodes whose sampling results are irrecoverable, and then remove the isolated nodes and local passive networks, record the power grid state after the current round of sampling simulation and removal; and calculate the importance of the power generation nodes, non-power generation nodes and lines respectively based on the power grid state of the current round of sampling simulation;

[0043] The time point iteration module is used to increase the number of iterations by one if the current sampling time point is less than the number of sampling time points, and return to sampling line by line to continue iteration, otherwise proceed to the next step;

[0044] The round iteration module is used to increase the number of iterations by one if the number of sampling simulation rounds is less than the preset maximum number of sampling simulation iterations, and return to the initialization of the calculation parameters of this round to continue the iteration, otherwise proceed to the next step.

[0045] In one embodiment, the state analysis module includes: a line-by-line sampling module and a group sampling module, wherein:

[0046] The line-by-line sampling module is used to sample the single fault probability at that time point for each line, select any line to be detected, and if the sampling random number is less than the single fault probability of the line to be detected, determine that a permanent fault occurs in the line to be detected and mark it as an unrecoverable state; otherwise, mark it as a recoverable state, and sample the operation time of the line to be detected based on the switch operation time opening rate distribution;

[0047] The group transmission sampling module is used to sort out the constituent lines of the group transmission in the power grid, calculate the product of the random sampling values ​​of the constituent lines in each group transmission, and if the product value is less than the group transmission failure probability of the group transmission, it is determined that the group transmission has a group transmission failure and is marked as an unrecoverable state. Otherwise, it is marked as a recoverable state.

[0048] In one embodiment, the formula for calculating the importance of power generation nodes, non-power generation nodes and lines includes:

[0049]

[0050] In the formula, Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Indicates the importance of the line; ω1 and ω2 represent weight values; represents the normalized node betweenness; I′ G,m I′ represents the expected revenue of the power generation node after normalization; B,m represents the expected revenue of non-generation nodes after normalization; represents the betweenness of the kth line under the current power grid status; Indicates the number of shortest paths between nodes s and t in the current power grid state; represents the number of shortest paths between nodes s and t passing through line k; V represents the set of nodes in the network; m represents a node.

[0051] In one embodiment, the formula for calculating the importance index and expected operation time of the damaged transmission line and node includes:

[0052]

[0053] In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; N t represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

[0054] According to a third aspect of an embodiment of the present invention, a device for evaluating an expected value of node recovery importance is provided.

[0055] In some embodiments, the node recovery importance expected value evaluation device includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0056] According to a fourth aspect of embodiments of the present invention, a computer-readable storage medium is provided.

[0057] In one embodiment, the computer-readable storage medium stores a computer program, and the computer program implements the steps of the above method when executed by a processor.

[0058] The technical solution provided by the embodiment of the present invention may include the following beneficial effects: according to the probability of line failure caused by disasters, a time-series Monte Carlo simulation is performed to simulate the recoverable state under the disaster, and the expected value of importance under the simulated recoverable state is evaluated, so that the node importance considering the impact of disaster uncertainty can be dynamically evaluated and updated online, and at the same time, the expected value indicators of node and line importance applicable to the entire process of restoring the power grid under disaster conditions are calculated, thereby significantly improving the ability to identify key nodes and lines of the power grid in the recovery state, and providing support for the subsequent construction of the target grid for power grid recovery.

[0059] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0061] Figure 1 is a flowchart of a method for evaluating an expected value of node recovery importance according to an exemplary embodiment;

[0062] Figure 2 is a structural diagram of a node recovery importance expected value evaluation system according to an exemplary embodiment;

[0063] Figure 3 The figure is a schematic diagram showing the structure of a computer device according to an exemplary embodiment. DETAILED DESCRIPTION

[0064] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0065] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0066] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0067] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0068] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0069] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0070] Each module in the device or system of the present application can be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above modules.

[0071] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0072] Figure 1 An embodiment of the node recovery importance expected value evaluation method of the present invention is shown.

[0073] In this optional embodiment, the node recovery importance expected value evaluation method includes:

[0074] Step S101, obtaining power grid operation information and transmission line fault probability assessment results, and initializing overall calculation parameters and current round calculation parameters of sampling simulation based on the transmission line fault probability assessment results;

[0075] Step S103: through iterative sampling of restorable state sampling simulation, identify the power grid status of the transmission lines and nodes at each time point in turn, remove the transmission lines and nodes that do not meet the restorable requirements in each round of sampling results, and calculate the importance of the retained transmission lines and nodes;

[0076] Step S105: Integrate the sampling results after all iteration rounds, and calculate the importance index and expected operation time of the damaged transmission lines and nodes based on the importance of the transmission lines and nodes.

[0077] In this optional embodiment, when obtaining power grid operation information and transmission line fault probability assessment results, and initializing the overall calculation parameters and current round calculation parameters of the sampling simulation based on the transmission line fault probability assessment results, the power grid operation information can be collected, and based on the time scale of the external disaster evolution, the transmission line fault probability assessment results can be generated using online assessment software, and the transmission line fault probability assessment results include the assessment results of single fault probability and the assessment results of group fault probability; based on the transmission line fault probability assessment results, the recoverable and irrecoverable states of the lines and nodes in the power grid are defined, and the overall calculation parameters of the sampling simulation of the recoverable state and the current round calculation parameters when starting iterative sampling are initialized.

[0078] In this optional embodiment, the nodes include power generation nodes and non-power generation nodes; the overall calculation parameters include the total number of sampling simulation rounds, the number of sampling simulation rounds, the initial value of the number of times the sampling simulation results of each line are in an irrecoverable state, the initial value of the number of times the sampling simulation results of each node are in an irrecoverable state, and the total evaluation period and time point.

[0079] In this optional embodiment, by iterative sampling of sampling simulation of recoverable states, the grid states of transmission lines and nodes at various time points are identified in turn, the transmission lines and nodes that do not meet the recoverable requirements in each round of sampling results are eliminated, and the importance of the retained transmission lines and nodes is calculated. The time point of this round of sampling simulation can be set, and the recoverable state and irrecoverable state of each line in the power grid can be identified by sampling line by line, and the operation time of the sampled lines is calculated. By integrating the random sampling values ​​of the constituent lines in the group, the recoverable state and irrecoverable state of each group are analyzed; remove the sampling line. The result is the lines and nodes in an unrecoverable state, and then the isolated nodes and local passive networks are removed, and the grid state after this round of sampling simulation is recorded and removed; and based on the grid state of this round of sampling simulation, the importance of power generation nodes, non-power generation nodes and lines are calculated respectively; if the current sampling time point is less than the number of sampling time points, the number of iterations is increased by one, and the sampling of each line is returned to continue iterating, otherwise proceed to the next step; if the number of sampling simulation rounds is less than the preset maximum number of sampling simulation iterations, the number of iterations is increased by one, and it returns to the initialization of the calculation parameters of this round, and the iteration continues, otherwise proceed to the next step.

[0080] In this optional embodiment, when setting the time point of this round of sampling simulation, the recoverable state and the irrecoverable state of each line in the power grid are identified by sampling line by line, and when calculating the operation time of the sampled line and analyzing the recoverable state and the irrecoverable state of each cluster by integrating the random sampling values ​​of the constituent lines in the cluster, the single fault probability of the time point can be sampled line by line, and any line to be detected is selected. If the sampling random number is less than the single fault probability of the line to be detected, it is determined that a permanent fault occurs in the line to be detected and it is marked as an irrecoverable state. Otherwise, it is marked as a recoverable state, and based on the switch operation time opening rate distribution, the operation time of the line to be detected is sampled; the constituent lines of the cluster in the power grid are combed, and the product of the random sampling values ​​of the constituent lines in each cluster is calculated. If the product value is less than the cluster failure probability of the cluster, it is determined that the cluster has a cluster failure and it is marked as an irrecoverable state. Otherwise, it is marked as a recoverable state.

[0081] In this optional embodiment, the formula for calculating the importance of power generation nodes, non-power generation nodes and lines includes:

[0082]

[0083] In the formula, Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Indicates the importance of the line; ω1 and ω2 represent weight values; represents the normalized node betweenness; I′ G,m I′ represents the expected revenue of the power generation node after normalization; B,m represents the expected revenue of non-generation nodes after normalization; represents the betweenness of the kth line under the current power grid status; Indicates the number of shortest paths between nodes s and t in the current power grid state; represents the number of shortest paths between nodes s and t passing through line k; V represents the set of nodes in the network; m represents a node.

[0084] In this optional embodiment, the formula for calculating the importance index and expected operation time of the damaged transmission line and node includes:

[0085]

[0086] In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; Nt represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

[0087] Figure 2 An embodiment of the node recovery importance expected value evaluation system of the present invention is shown.

[0088] In this optional embodiment, the node recovery importance expected value evaluation system includes:

[0089] Initialization module 201, used to obtain power grid operation information and transmission line fault probability assessment results, and initialize overall calculation parameters and current round calculation parameters of sampling simulation based on the transmission line fault probability assessment results;

[0090] The sampling simulation module 203 is used to sequentially identify the grid status of the transmission lines and nodes at each time point through iterative sampling of the sampling simulation of the recoverable state, eliminate the transmission lines and nodes that do not meet the recoverable requirements in each round of sampling results, and calculate the importance of the retained transmission lines and nodes;

[0091] The calculation and evaluation module 205 is used to integrate the sampling results after all iteration rounds are completed, and calculate the importance index and the expected value of the operation time of the damaged transmission lines and nodes based on the importance of the transmission lines and nodes.

[0092] In this optional embodiment, the initialization module 201 includes: a data acquisition module (not shown in the figure) and a parameter setting module (not shown in the figure), wherein the data acquisition module is used to collect power grid operation information, and based on the time scale of external disaster evolution, uses online evaluation software to generate a transmission line failure probability assessment result, and the transmission line failure probability assessment result includes a single failure probability assessment result and a group failure probability assessment result; the parameter setting module is used to define the recoverable and irrecoverable states of lines and nodes in the power grid based on the transmission line failure probability assessment result, and initialize and set the overall calculation parameters of the sampling simulation of the recoverable state, as well as the current round of calculation parameters when starting iterative sampling.

[0093] In this optional embodiment, the nodes include power generation nodes and non-power generation nodes; the overall calculation parameters include the total number of sampling simulation rounds, the number of sampling simulation rounds, the initial value of the number of times the sampling simulation results of each line are irrecoverable, the initial value of the number of times the sampling simulation results of each node are irrecoverable, and the total evaluation period and time point.

[0094] In this optional embodiment, the sampling simulation module 203 includes: a state analysis module (not shown in the figure), an importance calculation module (not shown in the figure), a time point iteration module (not shown in the figure) and a round number iteration module (not shown in the figure), wherein the state analysis module is used to set the time point of this round of sampling simulation, identify the recoverable state and irrecoverable state of each line in the power grid by sampling line by line, calculate the operation time of the sampled line, and analyze the recoverable state and irrecoverable state of each group by integrating the random sampling values ​​of the constituent lines in the group; the importance calculation module is used to remove the sampling results that are irrecoverable The lines and nodes in complex states are removed, and isolated nodes and local passive networks are removed, and the state of the power grid after this round of sampling simulation is recorded and removed; and based on the power grid state of this round of sampling simulation, the importance of power generation nodes, non-power generation nodes and lines are calculated respectively; the time point iteration module is used to increase the number of iterations by one if the current sampling time point is less than the number of sampling time points, and return to sampling line by line, and continue iteration, otherwise proceed to the next step; the round number iteration module is used to increase the number of iterations by one if the number of sampling simulation rounds is less than the preset maximum sampling simulation iteration round, and return to the initialization of the calculation parameters of this round, and continue iteration, otherwise proceed to the next step.

[0095] In this optional embodiment, the state analysis module (not shown in the figure) includes: a line-by-line sampling module (not shown in the figure) and a group sampling module (not shown in the figure), wherein the line-by-line sampling module is used to sample the single fault probability of each line at that time point, select any line to be detected, and if the sampling random number is less than the single fault probability of the line to be detected, then the line to be detected is determined to have a permanent fault and is marked as an irrecoverable state, otherwise, it is marked as a recoverable state, and based on the switch operation time opening rate distribution, the operation time of the line to be detected is sampled; the group sampling module is used to comb the constituent lines of the group in the power grid, calculate the product of the random sampling values ​​of the constituent lines in each group, and if the product value is less than the group failure probability of the group, then it is determined that the group has a group failure and is marked as an irrecoverable state, otherwise, it is marked as a recoverable state.

[0096] In this optional embodiment, the formula for calculating the importance of power generation nodes, non-power generation nodes and lines includes:

[0097]

[0098] In the formula, Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Indicates the importance of the line; ω1 and ω2 represent weight values; represents the normalized node betweenness; I′ G,mI′ represents the expected revenue of the power generation node after normalization; B,m represents the expected revenue of non-generation nodes after normalization; represents the betweenness of the kth line under the current power grid status; Indicates the number of shortest paths between nodes s and t in the current power grid state; represents the number of shortest paths between nodes s and t passing through line k; V represents the set of nodes in the network; m represents a node.

[0099] In this optional embodiment, the formula for calculating the importance index and expected operation time of the damaged transmission line and node includes:

[0100]

[0101] In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; N t represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

[0102] The present invention is further described in detail below in conjunction with specific implementation modes.

[0103] S1: Obtain the grid operation information, the transmission line single fault probability assessment results, the transmission line group fault probability assessment results, and perform overall calculation initialization. The initialization includes: setting the total number of sampling simulation rounds N s , set the initial value of the sampling simulation round number i=1, i=1,2,N s , the number of times the sampling simulation results of each line are in an unrecoverable state The initial value of k=1,2,……N L , N L is the total number of lines, and the sampling simulation results of each node are the number of times the irrecoverable state The initial value of m=1,2,……N N , N N is the total number of nodes; set the total evaluation period T E , and further T E Divide into Nt Time point, N t The specific value of depends on the time scale of the evolution of external disasters.

[0104] The above-mentioned transmission line failure probability assessment results refer to the probability of a single failure or a group failure of equipment caused by the health status of the power grid itself or external disaster factors. It is evaluated online by a dedicated software module. The assessment results include but are not limited to faulty components, fault types, and failure probabilities at several future time points. The interval between time points depends on the time scale of the evolution of external disasters.

[0105] S2: According to the probability evaluation result, initialize this round of Monte Carlo sampling simulation, and enter S3 to start the i-th round of sampling simulation.

[0106] Among them, Monte Carlo sampling simulation, also known as sampling simulation of recoverable state, further referred to as sampling simulation, refers to sampling simulation based on the probability of transmission line failure to determine whether a permanent fault occurs at the corresponding point in time, and permanent line failure is regarded as an irrecoverable state. If there is no permanent fault in the line and it has not been repaired, it is a recoverable state.

[0107] Initialization of this round of sampling simulation includes setting the initial value of the time point sequence number in this round j = 1, j = 1, 2, N t Each round of smoking simulation contains N t At this point in time, the initial state of the line and node in this round is set to a recoverable state;

[0108] The above-mentioned recoverable state includes the recoverable state of the line and the node. The recoverable state of the line means that the line has no permanent fault and has not been shut down for maintenance, and can be put into operation as a power supply path. Otherwise, it is an irrecoverable state. The recoverable state of the node means whether the node can be restored to the powered operation state by receiving external power supply. If so, it is a recoverable state, otherwise it is an irrecoverable state.

[0109] The above nodes refer to power plants or substations in the power grid, which are respectively called power generation nodes and non-power generation nodes.

[0110] S3: For the jth time point of this round of sampling simulation, if j>1, then the grid state after sampling simulation at the j-1th time point of this round is If j = 1, then the actual state of the power grid is (When j>1, the state after sampling simulation at the previous time point is the initial state of sampling simulation at the jth time point. When sampling for the first time, that is, when j=1, there is no sampling simulation state at the previous time point, so the current actual state of the power grid should be used as the initial state. Since when j=1 and j>1, the symbol represents the initial state for sampling at the jth time point, the same variable symbol is used for the power grid states at two different time points because their meanings are consistent and correspond to different j values.) Based on Execute the sampling simulation step of the recoverable state, sample and simulate the recoverable state of the line and node at that time point, and the recovery operation time of the line; then Remove the lines and nodes whose sampling results are irrecoverable from the power grid in the state, and record the power grid state after removal as

[0111] The sampling simulation steps of the recoverable state include:

[0112] a) Sample each line according to its single fault probability at time point j. For any k-th line L k , if the sampling random number is less than L k Failure probability, then L k A permanent failure has occurred and the system is in an unrecoverable state. Otherwise, it is a recoverable state. At this time, based on the probability distribution of switch operation time, the operation time of the line is sampled.

[0113] b) Sample the unrecoverable state caused by the group fault one by one according to the probability of all group faults at time point j, that is, if the product of the random sampling values ​​of each component line of the group in step a) is less than the probability of the group fault, it is considered that the group fault has occurred and the component lines are all in an unrecoverable state. For example, fi is the fault number, if the component line L of the fault in step a) k1 , L k2 If the product of the random number sampling is less than the fault probability, it is considered that the group fault has occurred and both lines are in an unrecoverable state. The same goes for other group failures;

[0114] Remove the lines and nodes whose sampling results are irrecoverable, and record the power grid status after removal as Including: According to the sampling results, from Remove the network from the state to be restored Then analyze the isolated nodes or local passive networks and remove them. The removed lines and nodes are irreversible. The current grid state after sampling simulation is recorded as

[0115] S4: Based on Calculate the importance of power generation nodes and non-power generation nodes, respectively Calculate the importance of the line as follows: The importance of irrecoverable lines and nodes is 0;

[0116]

[0117] In the formula, for The betweenness of line k in state, yes The number of shortest paths from node s to node t in the state, It is the number of shortest paths between nodes s and t through line k, and the sum of reactance and susceptance is used as the line weight; V is the set of nodes in the network.

[0118] The calculation formula for the importance of the above power generation nodes and non-power generation nodes is as follows:

[0119]

[0120] S5: If j<N t , then j=j+1, return to S3, otherwise go to the next step, N t is the number of sampling points;

[0121] S6: If i<N s , then i=i+1, return to S2, otherwise go to the next step, N s is the preset maximum number of iterations;

[0122] S7: Based on all N s Round results, calculate T according to the following formula E Importance index of lines, power generation nodes, and non-power generation nodes affected by disasters and operation time expectation

[0123]

[0124] In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; N t represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

[0125] In one embodiment, a node recovery importance expected value evaluation device is provided. The device may be a server, and its internal structure diagram may be as follows: Figure 3 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store static information and dynamic information data. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps in the above method embodiment are implemented.

[0126] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0127] In addition, the present invention also provides a computer device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiment when executing the computer program.

[0128] In addition, the present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the above method embodiment are implemented.

[0129] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0130] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for evaluating the expected value of node recovery importance, characterized in that: include: Obtaining grid operation information and transmission line fault probability assessment results, and initializing overall calculation parameters and current round calculation parameters of sampling simulation based on the transmission line fault probability assessment results; Through iterative sampling of restorable state sampling simulation, the power grid status of transmission lines and nodes at each time point is identified in turn, the transmission lines and nodes that do not meet the restorable requirements in each round of sampling results are eliminated, and the importance of the retained transmission lines and nodes is calculated; The sampling results after all iterations are integrated, and based on the importance of transmission lines and nodes, the importance index and expected operation time of damaged transmission lines and nodes are calculated.

2. The node recovery importance expected value evaluation method according to claim 1 is characterized in that: The obtaining of the grid operation information and the transmission line fault probability assessment result, based on the transmission line fault probability assessment result, initializing the overall calculation parameters of the sampling simulation and the current round of calculation parameters include: Collecting grid operation information, and using online evaluation software to generate transmission line failure probability evaluation results based on the time scale of external disaster evolution, wherein the transmission line failure probability evaluation results include single failure probability evaluation results and group failure probability evaluation results; Based on the transmission line fault probability assessment result, the recoverable state and the irrecoverable state of the lines and nodes in the power grid are defined, and the overall calculation parameters of the sampling simulation of the recoverable state and the calculation parameters of the current round when starting iterative sampling are initialized.

3. The node recovery importance expected value evaluation method according to claim 2 is characterized in that: The nodes include power generation nodes and non-power generation nodes; the overall calculation parameters include the total number of sampling simulation rounds, the number of sampling simulation rounds, the initial value of the number of times the sampling simulation results of each line are in an irrecoverable state, the initial value of the number of times the sampling simulation results of each node are in an irrecoverable state, and the total evaluation period and time point.

4. The node recovery importance expected value evaluation method according to claim 1 is characterized in that: The iterative sampling of the sampling simulation of the recoverable state sequentially identifies the grid state of the transmission lines and nodes at each time point, removes the transmission lines and nodes that do not meet the recoverable requirements in each round of sampling results, and calculates the importance of the retained transmission lines and nodes, including: Set the time point of this round of sampling simulation, identify the recoverable and irrecoverable states of each line in the power grid by sampling line by line, calculate the operation time of the sampled lines, and analyze the recoverable and irrecoverable states of each group by integrating the random sampling values ​​of the constituent lines in the group; Remove the lines and nodes with irrecoverable status in the sampling results, and then remove the isolated nodes and local passive networks, and record the grid status after this round of sampling simulation and removal; and based on the grid status of this round of sampling simulation, calculate the importance of power generation nodes, non-power generation nodes and lines respectively; If the current sampling time point is less than the sampling time point number, the number of iterations is increased by one, and the sampling of each line is returned to continue iteration, otherwise it goes to the next step; If the number of sampling simulation rounds is less than the preset maximum number of sampling simulation iteration rounds, the number of iterations is increased by one, and the process returns to the initialization of the calculation parameters of this round and continues to iterate, otherwise it proceeds to the next step.

5. The method for evaluating expected value of node recovery importance according to claim 4, characterized in that: The time point of setting the sampling simulation in this round is identified by sampling each line, and the recoverable state and irrecoverable state of each line in the power grid are identified. The operation time of the sampled line is calculated, and the recoverable state and irrecoverable state of each group are analyzed by integrating the random sampling values ​​of the constituent lines in the group. The method includes: The single fault probability of each line is sampled at that time point. Any line to be tested is selected. If the sampling random number is less than the single fault probability of the line to be tested, the line to be tested is judged to have a permanent fault and marked as an unrecoverable state. Otherwise, it is marked as a recoverable state. Based on the switch operation time opening rate distribution, the operation time of the line to be tested is sampled; Comb the constituent lines of the cluster in the power grid, calculate the product of the random sampling values ​​of the constituent lines in each cluster, and if the product value is less than the cluster failure probability of the cluster, it is determined that the cluster has a cluster failure and is marked as an unrecoverable state. Otherwise, it is marked as a recoverable state.

6. The method for evaluating the expected value of node recovery importance according to claim 5, characterized in that: The formula for calculating the importance of power generation nodes, non-power generation nodes and lines includes: In the formula, Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Indicates the importance of the line; ω1 and ω2 represent weight values; represents the normalized node betweenness; I′ G,m I′ represents the expected revenue of the power generation node after normalization; B，m represents the expected revenue of non-generation nodes after normalization; represents the betweenness of the kth line under the current power grid status; Indicates the number of shortest paths between nodes s and t in the current power grid state; represents the number of shortest paths between nodes s and t passing through line k; V represents the set of nodes in the network; m represents a node.

7. The node recovery importance expected value evaluation method according to claim 1 is characterized in that: The formula for calculating the importance index and expected operation time of damaged transmission lines and nodes includes: In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; N t represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

8. A node recovery importance expected value evaluation system, characterized in that: include: An initialization module is used to obtain power grid operation information and transmission line fault probability assessment results, and initialize the overall calculation parameters of the sampling simulation and the current round of calculation parameters based on the transmission line fault probability assessment results; The sampling simulation module is used to identify the grid status of the transmission lines and nodes at each time point in turn through iterative sampling of the sampling simulation of the recoverable state, eliminate the transmission lines and nodes that do not meet the recoverable requirements in each round of sampling results, and calculate the importance of the retained transmission lines and nodes; The calculation and evaluation module is used to integrate the sampling results after all iteration rounds, and calculate the importance index and expected operation time of the damaged transmission lines and nodes based on the importance of the transmission lines and nodes.

9. The node recovery importance expected value evaluation system according to claim 8, characterized in that: The initialization module includes: a data acquisition module and a parameter setting module, wherein: The data acquisition module is used to collect power grid operation information, and based on the time scale of external disaster evolution, generates a transmission line fault probability assessment result using online assessment software, and the transmission line fault probability assessment result includes a single fault probability assessment result and a group fault probability assessment result; The parameter setting module is used to define the recoverable and irrecoverable states of the lines and nodes in the power grid based on the transmission line fault probability assessment result, and initialize and set the overall calculation parameters of the sampling simulation of the recoverable state, as well as the current round of calculation parameters when starting iterative sampling.

10. The node recovery importance expected value evaluation system according to claim 9, characterized in that: The nodes include power generation nodes and non-power generation nodes; the overall calculation parameters include the total number of sampling simulation rounds, the number of sampling simulation rounds, the initial value of the number of times the sampling simulation results of each line are in an irrecoverable state, the initial value of the number of times the sampling simulation results of each node are in an irrecoverable state, and the total evaluation period and time point.

11. The node recovery importance expected value evaluation system according to claim 8, characterized in that: The sampling simulation module includes: a state analysis module, an importance calculation module, a time point iteration module and a round number iteration module, wherein: The state analysis module is used to set the time point of this round of sampling simulation, identify the recoverable state and irrecoverable state of each line in the power grid by sampling line by line, calculate the operation time of the sampled line, and analyze the recoverable state and irrecoverable state of each group by integrating the random sampling values ​​of the constituent lines in the group; The importance calculation module is used to remove the lines and nodes whose sampling results are irrecoverable, and then remove the isolated nodes and local passive networks, record the power grid state after the current round of sampling simulation and removal; and calculate the importance of the power generation nodes, non-power generation nodes and lines respectively based on the power grid state of the current round of sampling simulation; The time point iteration module is used to increase the number of iterations by one if the current sampling time point is less than the number of sampling time points, and return to sampling line by line to continue iteration, otherwise proceed to the next step; The round iteration module is used to increase the number of iterations by one if the number of sampling simulation rounds is less than the preset maximum number of sampling simulation iterations, and return to the initialization of the calculation parameters of this round to continue the iteration, otherwise proceed to the next step.

12. The node recovery importance expected value evaluation system according to claim 11, characterized in that: The state analysis module includes: a line-by-line sampling module and a group sampling module, wherein: The line-by-line sampling module is used to sample the single fault probability at that time point for each line, select any line to be detected, and if the sampling random number is less than the single fault probability of the line to be detected, determine that a permanent fault occurs in the line to be detected and mark it as an unrecoverable state; otherwise, mark it as a recoverable state, and sample the operation time of the line to be detected based on the switch operation time opening rate distribution; The group transmission sampling module is used to sort out the constituent lines of the group transmission in the power grid, calculate the product of the random sampling values ​​of the constituent lines in each group transmission, and if the product value is less than the group transmission failure probability of the group transmission, it is determined that the group transmission has a group transmission failure and is marked as an unrecoverable state. Otherwise, it is marked as a recoverable state.

13. The node recovery importance expected value evaluation system according to claim 12, characterized in that: The formula for calculating the importance of power generation nodes, non-power generation nodes and lines includes: In the formula, Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Indicates the importance of the line; ω1 and ω2 represent weight values; represents the normalized node betweenness; I′ G,m I′ represents the expected revenue of the power generation node after normalization; B,m represents the expected revenue of non-generation nodes after normalization; represents the betweenness of the kth line under the current power grid status; Indicates the number of shortest paths between nodes s and t in the current power grid state; represents the number of shortest paths between nodes s and t passing through line k; V represents the set of nodes in the network; m represents a node.

14. The node recovery importance expected value evaluation system according to claim 8, characterized in that: The formula for calculating the importance index and expected operation time of damaged transmission lines and nodes includes: In the formula, Indicates the line importance index; Indicates the importance index of power generation node; Represents the importance index of non-generation nodes; Indicates the expected value of operation time; N s Indicates the maximum number of iterations preset for sampling simulation; N t represents the sampling time point; i represents the round of sampling simulation; j represents the time point; Indicates the importance of the line; Indicates the importance of the power generation node; Indicates the importance of non-generation nodes; Represents the operation time of sampling the kth line.

15. A device for evaluating expected value of node recovery importance, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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