Substation safety risk assessment method and device considering interval power failure, and storage medium

Abstract

The invention discloses a substation safety risk assessment method and device considering interval power failure and a storage medium, and belongs to the technical field of relay protection and power system safety analysis. The method comprises the following steps: acquiring a historical interval fault event set causing fault disturbance of the integrated substation system; based on a brainstorm algorithm, determining a historical interval fault event which has the greatest influence on the system from the historical interval fault event set; acquiring corresponding system operation data when the fault interval or the transformation interval parallelly generates the maximum historical interval fault event in the power failure period; power failure risks and equipment risks of other operation intervals in each transformer substation are calculated according to the system operation data, and then the overall operation risk value of each transformer substation in the system management range is determined based on the power failure risks and the equipment risks. According to the method, the in-station interval is used as a basic research unit, the overall operation risk value of the transformer substation corresponding to a major fault occurring again after interval power failure transformation can be effectively pre-judged, and the practicability is high.

Description

Technical Field

[0001] The invention relates to a substation safety risk assessment method, device and storage medium considering interval power outages, and belongs to the technical field of relay protection and power system safety analysis. Background Art

[0002] As the main bearer in the process of power transmission, the substation not only contains a large number of expensive primary equipment, but also is equipped with a variety of secondary equipment such as measurement, protection, control, communication and monitoring. It is inevitable that the substation needs to be partially shut down during operation. In this process, due to the change in the operation mode of the substation, not only the reliability of power supply will be reduced, but also the backup capacity of the power grid will be reduced, resulting in an increase in the operation risk of the power grid after being disturbed by a fault. Therefore, when there is an interval for maintenance, the power department often determines the switch opening and closing process and various response measures during the maintenance period, that is, when the system is in the N-1 state, in advance to ensure the overall safety of the power grid operation.

[0003] However, during the power outage renovation of the above-mentioned intervals, many unknown and different fault events may occur in the other intervals in the integrated substation system. When these unknown faults are superimposed on the intervals undergoing maintenance, this may have a significant impact on the stable operation of the system. Therefore, in view of the uncertain situation that other intervals may have unknown faults of varying degrees, how to take preventive measures of the maximum level in advance and effectively has become a major technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a substation safety risk assessment method, device and storage medium taking into account interval power outages, aiming to optimize the safety risk assessment of the power grid during power outage transformation through innovative methods, especially when dealing with potential faults, to more accurately identify high-risk areas and adjust the monitoring strategy accordingly.

[0005] In order to achieve the above objectives / solve the above technical problems, the present invention is implemented by adopting the following technical solutions.

[0006] On the one hand, the present invention provides a substation safety risk assessment method considering interval power outages, which includes: Obtain a historical interval fault event set causing a fault disturbance in the integrated substation system; Based on a brainstorming optimization algorithm, determining the historical interval fault event with the greatest impact on the integrated substation system from the historical interval fault event set; Obtain system operation data corresponding to the historical interval fault event with the greatest impact on the integrated substation system that occurs in parallel with the known fault interval or the transformation interval during the power outage; According to the system operation data, the power outage risk and equipment risk of the remaining operation intervals in each substation are calculated, and then based on the power outage risk and equipment risk of the remaining operation intervals in each substation, the overall operation risk value of each substation within the system management scope is determined.

[0007] The present invention comprehensively considers the operating data of the integrated substation system under the state of secondary bay fault, combines the brainstorming optimization algorithm to screen fault events, and finally generates a strategy table to guide transformation or maintenance. The safety risk assessment method helps to improve the safety and reliability of the substation system and reduce the potential risks caused by secondary major fault events that may occur during bay transformation.

[0008] Optionally, the power outage risks of the remaining operating intervals in each substation include: a first power outage risk corresponding to a power outage in the operating interval caused by a known fault interval or a modified interval in the substation during a power outage, and a second power outage risk corresponding to a power outage in the upper-level circuit breaker interval due to a failure of the circuit breaker in the operating interval to cut off power due to a fault.

[0009] Optionally, the calculation formula of the first power outage risk is expressed as: ; In the formula, Indicates that a known fault bay or modified bay in the substation causes a power outage in the operating bay during the power outage The corresponding first power outage risk, Indicates the running interval The outgoing line load factor, Indicates the price of electricity per kilowatt-hour. Indicates the interval of power outage for maintenance Planned outage interval with simulated secondary failure After a fault occurs, the running interval The probability of power outage due to fault, Indicates the interval The time of power outage, Indicates the running interval Power outage recovery time Indicates the running interval exist arrive The transmission power during the time period.

[0010] Optionally, the calculation formula of the second power outage risk is expressed as: ; In the formula, Indicates the running interval The second power outage risk corresponding to the power outage of the upper-level circuit breaker due to the failure of the circuit breaker to cut off the power under fault conditions, It indicates the accident rate of circuit breaker transformer according to the working time. Indicates the interval The time of power outage, Indicates the interval Estimated time for power outage restoration, Indicates the running interval The power predicted by the power curve during the power outage period of the previous power outage range, Indicates the running interval The operating time of the circuit breaker.

[0011] Optional, if the load carried by the outgoing line is only from the operating interval Power supply, then the running interval The outgoing line load factor is 1; if the outgoing line load is supplied by multiple intervals, the operating interval The outgoing line load factor is 0.

[0012] Optionally, the equipment risk of the remaining operating intervals in each substation is calculated by the following formula: ; In the formula, Indicates the running interval Equipment risks, Indicates the running interval Overall one-time equipment cost.

[0013] Optionally, based on the power outage risk and equipment risk of the remaining operating intervals in each substation, the overall operating risk of each substation within the system management scope is determined, including: According to the power outage risk and equipment risk of each of the operating intervals, an overall operating risk value of each of the operating intervals is calculated; Considering the overall operation risk values ​​of all operation intervals in each substation and the overall operation risk values ​​of the intervals directly connected to the adjacent stations of each substation, the initial overall operation risk value of each substation is determined; Obtaining a preset risk value at the same level corresponding to each substation within the system management scope, and using the preset risk value as a risk reference value corresponding to each substation; According to the initial overall operation risk value of each substation and the risk reference value corresponding to each substation, the risk per unit value corresponding to each substation is calculated, and the risk per unit value is used as the overall operation risk value of each substation.

[0014] Optionally, according to the power outage risk and equipment risk of each operating interval, the overall operating risk value of each operating interval is calculated and expressed as: ; In the formula, Indicates the overall operation risk value corresponding to the operation interval, and Represent coefficients respectively, and satisfy .

[0015] Optionally, the overall operation risk value of all operation intervals in each substation and the overall operation risk value of the intervals directly connected to the adjacent stations of each substation are considered to determine the initial overall operation risk value of each substation, which is expressed as: ; In the formula, represents the initial overall operation risk value of each substation, Indicates the number of operating bays in the substation, Indicates the overall operation risk value of the direct connection interval between adjacent stations.

[0016] Optionally, the substation considering the interval power outage calculates the risk degree per unit value corresponding to each substation according to the initial overall operation risk value of each substation and the risk reference value corresponding to each substation, which is expressed as: ; In the formula, Indicates the risk level corresponding to each substation. It indicates the risk benchmark value selected by experts among substations of the same level.

[0017] Optionally, based on a brainstorming optimization algorithm, determining the historical interval fault event with the greatest impact on the integrated substation system from the historical interval fault event set includes: Based on the historical interval failure event set, generating an initial population and setting algorithm parameters; The initial population is clustered using a k-means clustering algorithm, and then the individuals contained in each class are sorted according to the fitness value, and the individual with the largest fitness is selected as the cluster center of the class; Based on the brainstorming algorithm, a random number is generated, and the corresponding operation type is determined according to the value of the random number; if the random number is less than or equal to the first threshold, an operation of selecting a random individual is performed, and a new individual is generated by adding random perturbations; if the random number is between the first threshold and the second threshold, an operation of selecting the center of a cluster or a random individual is performed, and a new individual is generated by adding random perturbations; if the random number is greater than or equal to the second threshold, an operation of selecting the centers of two clusters or random individuals is performed, the two individuals or cluster centers are merged, and a new individual is generated by adding random perturbations; Taking the risk per unit value as the fitness value, the new individual is compared with the cluster center, and the individual with a high fitness value is selected to enter the next generation; The above clustering, individual updating and selection operations are repeated until the preset number of iterations is reached. After the iteration is completed, the optimal solution corresponding to the bay fault event that has the greatest impact on the integrated substation system is output.

[0018] Optionally, according to the risk level per unit value corresponding to each substation, arranging the online refresh time of the state valuation includes: If the risk per unit value of the substation is within the preset level 1 risk range, the scanning interval of the corresponding operating data is set to one hour; if the risk per unit value of the substation is within the preset level 2 risk range, the scanning interval of the corresponding operating data is set to half an hour; if the risk per unit value of the substation is within the preset level 3 risk range, the scanning interval of the corresponding operating data is set to ten minutes; if the risk per unit value of the substation is within the preset level 4 risk range, the scanning interval of the corresponding operating data is set to five minutes.

[0019] In a second aspect, the present invention further provides a substation safety risk assessment device considering interval power outages, comprising: A historical interval fault acquisition module is configured to acquire a historical interval fault event set causing a fault disturbance in the integrated substation system; A secondary fault interval determination module is configured to determine, based on a brainstorming optimization algorithm, from the historical interval fault event set the historical interval fault event with the greatest impact on the integrated substation system; An operation data acquisition module is configured to acquire system operation data corresponding to a historical interval fault event with the greatest impact on the integrated substation system that occurs in parallel with a known fault interval or a transformation interval during a power outage; In addition, the substation risk assessment module is configured to calculate the power outage risk and equipment risk of the remaining operating intervals in each substation based on the system operation data, and then determine the overall operation risk value of each substation within the system management scope based on the power outage risk and equipment risk of the remaining operating intervals in each substation.

[0020] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the substation safety risk assessment method considering interval power outages as described in the first aspect.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The present invention firstly utilizes a brainstorming algorithm, combined with the actual situation during the power outage transformation of the power grid, to screen out the optimal solution from the interval where the fault may occur again, and then based on the high-risk interval identified by the brainstorming algorithm, innovatively constructs a relay protection safety risk assessment model with the interval as the core to perform power outage risk assessment and equipment risk assessment of the operating interval. The problem is indexed through the assessment model to achieve accurate assessment of the safety risks of each substation in the power grid during the power outage transformation, effectively prevent the occurrence of power grid failures, and improve the safety and stability of the power grid; in addition, in order to ensure the real-time and accuracy of online monitoring, the present invention also dynamically adjusts the system's refresh time for risk values ​​of different substations according to the calculation results of the interval risk value. For the substation where the high-risk interval is located, the system will refresh the risk value more frequently to ensure that potential safety hazards are captured in time, and for the substation where the low-risk interval is located, the refresh time can be appropriately extended to reduce the system calculation complexity and resource consumption, which not only improves the operation efficiency of the power grid, but also reduces the system calculation complexity, providing a strong guarantee for the safe and stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of an embodiment of a method for assessing substation safety risk considering interval power outages according to the present invention; Figure 2 It is a flow chart of the brainstorming optimization algorithm in the substation safety risk assessment method considering interval power outages of the present invention; Figure 3 It is a schematic diagram of the risk value calculation process of the bay-station-system in the substation safety risk assessment method considering the bay power outage of the present invention; Figure 4 Shown is a flow chart of another embodiment of a method for assessing substation safety risks taking into account interval power outages according to the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0024] The term "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the associated objects are in an "or" relationship.

[0025] Example 1 refer to Figure 1 This embodiment introduces a substation safety risk assessment method considering interval power outages, which includes: Obtain a historical interval fault event set causing a fault disturbance in the integrated substation system; Based on a brainstorming optimization algorithm, determining the historical interval fault event with the greatest impact on the integrated substation system from the historical interval fault event set; Obtain system operation data corresponding to the historical interval fault event with the greatest impact on the integrated substation system that occurs in parallel with the known fault interval or the transformation interval during the power outage; According to the system operation data, the power outage risk and equipment risk of the remaining operation intervals in each substation are calculated, and then based on the power outage risk and equipment risk of the remaining operation intervals in each substation, the overall operation risk value of each substation within the system management scope is determined.

[0026] In the actual application process of this embodiment, the bay fault event set causing the fault disturbance of the integrated substation system is first extracted from the historical database. Based on the bay fault event set, the BrainStorm Optimization (BSO) algorithm is used to analyze the historical fault event set to determine the bay fault event with the greatest impact on the system. At the same time, the system operation state corresponding to the bay fault event with the greatest impact on the system occurring in parallel under the primary bay fault state is set as the secondary bay fault state.

[0027] After confirming the secondary bay fault state, start the data collection system to capture various operating data in real time under this state, and input the collected operating data under the secondary bay fault state into the relay protection safety risk assessment model with bay as the minimum consideration unit to calculate the overall operating risk value of each substation within the system management scope. The risk value should be able to reflect the comprehensive performance of the system in terms of stability, reliability and safety under the secondary bay fault state.

[0028] Example 2 refer to Figures 1 to 3 Based on Example 1, this example will introduce in detail the specific implementation process of the corresponding safety risk assessment of each substation considering the double bay fault disturbance.

[0029] 1. Construction of a substation safety risk assessment model based on interval In view of the operating characteristics of the substation, this embodiment takes the intervals within the station as the basic research unit to evaluate the unknown safety risks brought about by the possible further deterioration of the grid operation mode (N-1-n, secondary interval fault state) after a certain interval is powered off and renovated (N-1, primary interval fault state). The so-called unknown safety risk corresponds to the risk assessment of the system risk brought about by the equipment (N-1-n) that may be further forced to withdraw after N-1. Among them, the forced withdrawal of equipment after N-1 is often caused by a fault or abnormal operation. When it withdraws, the adverse impact on the system is greater, and the grid operation mode in this process will undergo certain significant changes. Therefore, it is very necessary to establish a relevant evaluation model to accurately estimate the unknown risk value brought about by the power outage transformation.

[0030] Regarding the selection of the target risk value prediction model, this embodiment forms a structural network of interval-station-system by constructing a relay protection safety risk assessment model with interval as the minimum consideration unit. In actual application, the relay protection safety risk assessment model mainly needs to consider the power outage risk (power outage loss) and equipment risk (expected equipment damage) of the substation interval. Among them, the power outage risk can be expressed by the electricity price, and the equipment risk can be expressed by the status of the near and far backup and whether the backup protection is missing, resulting in the possibility of equipment damage risk.

[0031] refer to Figure 3 Based on the above-mentioned power outage risks and equipment risks, the risks of each interval of the current substation, the whole, and the remaining substations can be determined, and then a strategy table can be formed for the different risk values ​​of each substation, so that when faced with corresponding situations, the risk value can be calculated online, and corresponding strategies can be taken in a timely and effective manner to reduce the risk value of the relevant substation.

[0032] 2. Based on the brainstorming algorithm, determine the fault solution that has the greatest impact on the system when the fault occurs again under the current interval fault state. First of all, it is worth pointing out that when one of the intervals is under maintenance, the power department will often have taken various measures in advance to determine the switch opening and closing process and various operating measures during the maintenance period when the system is in the N-1 state, so there is no need to further evaluate the risks in this state. However, during this period, there are still many different fault events that may occur in the other intervals. When these faults are superimposed on the maintenance interval at this time, they may have a greater impact on the stable operation of the system. Therefore, it is necessary to find out the fault with the greatest impact and make an overall risk assessment of the relevant substations in the event of this fault, so that the power department can take measures in advance or formulate corresponding strategy tables for substations with higher risks in this case, so as to avoid the high-risk risks that the substation may face when a fault really occurs and fail to solve them in time.

[0033] To know which fault event, i.e., in which case of N-1-n the system is most affected, the simplest method is to exhaustively enumerate n, and then calculate each case using the relay protection safety risk assessment model mentioned above, so as to obtain the worst evaluation value in which case of N-1-n. However, this method is extremely time-consuming and not suitable for use. If the random conjecture sorting is adopted, it is easy to fall into the local optimum and unable to find the global optimum solution. Therefore, this embodiment proposes to use the brainstorming algorithm to find the fault solution that has the greatest impact on the system, so as to quickly and reliably jump out of the local optimum solution and find the global optimum solution.

[0034] In addition, the current operation control of the power system is quite complete, and the static and dynamic security controls of the system are relatively reliable. Therefore, it is relatively common that n takes 1 or 2, that is, N-1-1 or N-1-2. Otherwise, the system may enter the islanding state, and the existing power system already has corresponding control and restoration measures for the islanding state. Refer to Figure 2 , this embodiment only conducts an example analysis for the N-1-1 state.

[0035] Specifically, first obtain the historical interval fault event set that causes fault disturbances in the integrated substation system.

[0036] Furthermore, use an algorithm to determine the interval fault event that has the greatest impact on the integrated substation system from the historical interval fault event set, that is, the interval where a fault occurs during the subsequent risk assessment application process . In this embodiment, the selection of the interval is obtained through the brainstorming optimization algorithm, and the relevant algorithm pseudocode is as follows: 1. Based on the historical interval fault event set, initialize the population size N and the maximum number of iterations T. Among them, N = dimension × margin, and the margin represents the operating mode of the system, such as the maximum operating mode, the minimum operating mode, etc.; the dimension dim represents the number of components that may be lost or the number of possible faults n listed; the maximum number of iterations T represents the number of times of excitation in each loop. For example: if there are one hundred operating modes and only one component loss is considered, there will be one hundred populations; if there are one hundred operating modes and two component losses are considered, there will be two hundred populations.

[0037] 2. Initialize the parameters and the population Xm, where m = 1, 2,..., N. For example: only considering the loss of a certain component, at this time the dimension is equal to 1 and the margin is equal to 2, then X1 is the target value under the large operating mode, and X2 is the target value under the small operating mode.

[0038] 3. While q < Q, do. Where q represents the number of loops.

[0039] 3.1. Cluster N individuals into K clusters using the k-means clustering algorithm. Roughly assign values ​​to different components or faults and different operating modes. For example, if a generator fault is assigned a value of 100*generator rated power and the maximum operation mode is assigned a value of 2, then the event of a generator component loss under the maximum operation mode can be assigned a value of 2*100*generator rated power. This method is used to quickly assign values ​​to each individual, which is convenient for k-means clustering. Randomly select K data points as initial cluster centers. By calculating the distance from the remaining fault events to each of the initial cluster centers, the remaining fault events are assigned to the initial cluster center closest to them to form corresponding clusters. Calculate the new centroid of each cluster, which is usually the mean of all points in the cluster, and complete the update of the cluster center. Repeat the assignment and update steps until the cluster center no longer changes significantly or reaches the preset number of iterations. For a large population, clustering into 3-5 categories is more appropriate.

[0040] 3.2. Based on the brainstorming algorithm, a random number is generated, and the corresponding operation type is determined according to the value of the random number; if the random number is less than or equal to the first threshold value 0.2, a random individual is found within the cluster range, and a new individual is generated by adding random perturbations; if the random number is between the first threshold value 0.2 and the second threshold value 0.8, an operation of selecting the center of a cluster or a random individual is performed, and a new individual is generated by adding random perturbations; if the random number is greater than or equal to the second threshold value 0.8, an operation of selecting the centers of two clusters or random individuals is performed, the two individuals or cluster centers are merged, and a new individual is generated by adding random perturbations.

[0041] Specifically, new individuals are generated by adding random perturbations to the centers or ordinary individuals in one or several clusters. When a cluster is selected to generate a new individual, the formula is as follows: ; In the formula, Indicates new ideas that arise. Express the original idea, Indicates the current iteration number, It is used to generate random numbers between 0 and 1. represents a coefficient that weights the contribution of random values ​​to new individuals; in, The calculation formula is as follows: ; In the formula, represents a transfer function, represents the maximum number of iterations, Indicates control The coefficient of the slope.

[0042] When two clusters are selected to generate new individuals, the formula is as follows: ; ; In the formula, express and The weighted sum of Represents a randomly generated coefficient between 0 and 1, and Represents ideas selected from two clusters respectively.

[0043] 3.3. Using the risk value as the fitness value, the new individuals mentioned above are compared with the determined cluster centers, and the ones with higher fitness are replaced as new cluster centers after being updated. The fitness value is the risk value of the system obtained by the state valuation of the target risk value model under the event corresponding to the selected individual. In other words, if the fitness of the new individual is higher, that is, the system risk is greater, it can be used to replace the new cluster center. In the process, the newly generated individuals are compared with the individuals in the existing cluster centers, and the individuals with larger loss values ​​are retained (more serious fault events are found) until the number limit is reached, and the final solution is output. The event corresponding to the solution is the event with the greatest impact on the system found by the brainstorming algorithm. Compared with the exhaustive method, there is no need to calculate the system risk value of each event, which reduces the time required. Compared with completely random enumeration, the probability of jumping out of the local optimal solution and reaching the global optimal solution is increased.

[0044] 3. Evaluation and application process of the overall operation risk value of each substation and formulation of relevant strategy tables In the actual risk assessment application process, it is necessary to first obtain the relevant operating data of the integrated substation system under the secondary interval fault state, and the secondary interval fault state mentioned here is the operating state corresponding to the interval fault event that has the greatest impact on the integrated substation system in parallel with the primary interval fault state. Further, the relevant operating data is input into the relay protection safety risk assessment model with the interval as the minimum consideration unit for risk assessment, and the overall operating risk value of each substation within the system management scope can be obtained, and then the corresponding strategy table is generated according to the overall operating risk value of each substation. The relevant implementation process is described as follows.

[0045] First, the running interval The security risk is modeled , mainly considering the risk of power outage in this interval and equipment risks The power outage risk of each interval is expressed as The impact on the electricity price of the output electricity during this time period during normal operation is calculated.

[0046] Among them, the power outage risk of other operating intervals in each substation , including: the first power outage risk corresponding to the power outage of the operating interval caused by the known fault interval or the modified interval in the substation during the power outage , and the second power outage risk corresponding to the power outage of the upper-level circuit breaker interval due to the failure of the circuit breaker in the operating interval to disconnect the power under the fault .

[0047] Set interval The interval is the interval that has been shut down for maintenance. To simulate the interval of failure, the interval is the interval of the current risk value calculation. Then the first power outage risk corresponding to the power outage of the operating interval caused by the known fault interval or transformation interval during the power outage is calculated by the following formula: That is, the system is in the state of interval failure N-1, and after a certain fault occurs again, the running interval The risk of power outage due to a fault is expressed as: ; In the formula, Indicates the running interval The outgoing line load factor, where if the outgoing line load is only from the operating interval Power supply, then the running interval The outgoing line load factor is 1. If the outgoing line load is supplied by multiple intervals, the operating interval The outgoing line load factor is 0; Indicates the price of electricity per kilowatt-hour; Indicates the interval of power outage for maintenance Planned outage interval with simulated secondary failure After a fault occurs, the running interval The probability of power outage due to a fault can be obtained from engineering experience; since the time of the fault is uncontrollable and unpredictable, in order to facilitate calculation, The value of The time point of maximum; Indicates the running interval Power outage recovery experience time; Indicates the running interval exist arrive The transmission power during the time period.

[0048] In addition, the operating interval must be considered When a circuit breaker fails, it may not be able to disconnect reliably, so the operating interval needs to be considered. The fault cannot be removed reliably and the upper level circuit breaker needs to be disconnected The possibility of disconnection. At this time, the scope of power outage expands, causing the risk of power outage, that is, the circuit breaker in the operating interval fails to disconnect due to a fault, resulting in the second power outage risk corresponding to the power outage of the upper-level circuit breaker interval , expressed as: ; In the formula, Based on engineering experience, according to the accident rate of circuit breaker transformers with working hours, Take normal operation so that The maximum value, Indicates the interval Estimated time for power outage restoration, Indicates the running interval The power predicted by the power curve during the power outage period of the previous power outage range, Indicates the running interval The operating time of the circuit breaker.

[0049] The first power outage risk corresponding to the power outage of the operating interval caused by the known fault interval or modified interval in the substation during the power outage , and the second power outage risk corresponding to the power outage of the upper-level circuit breaker interval due to the failure of the circuit breaker in the operating interval to disconnect the power under the fault , and finally the power outage risk of each operating interval can be calculated , so that its unit is converted into money, expressed as: ; In the formula, and They respectively represent the total incoming power of the substation in the corresponding time period.

[0050] When the running interval When a fault occurs, various situations such as overcurrent and overvoltage may occur. In particular, circuit breakers, transformers and other equipment will be subjected to greater impacts and are more likely to be damaged. Failures of these two types of equipment will pose a greater risk to system operation. Therefore, it is necessary to use engineering experience to determine the accident rate of circuit breakers and transformers according to the length of working time. , and whether there is backup protection to calculate the equipment risk and the equipment risk of the operating interval , the corresponding calculation formula is expressed as: ; In the formula, Indicates the running interval Equipment risks, Indicates the running interval Overall primary equipment cost.

[0051] The risk of power outage according to each of the stated operating intervals and equipment risks , the overall operation risk value of each operation interval is calculated and expressed as: ; In the formula, Indicates the running interval The corresponding overall risk value is and Represent coefficients respectively, and satisfy .

[0052] Furthermore, by comprehensively considering the overall operation risk value of each operating interval of the current substation and the overall operation risk value of the interval directly connected to the adjacent station of the substation, the initial overall operation risk value of the current substation is calculated, and then the initial overall operation risk value of each substation in the system is added to obtain the corresponding risk value of the entire system. , the above can be used as the state estimation of the system when the secondary interval fault state is N-1-n. Among them, the calculation formula of the initial overall operation risk value of the current substation overall operation is expressed as: ; In the formula, Indicates the initial overall operation risk value of a substation at present. Indicates the number of operating bays in the substation, Indicates the overall operational risk value of the direct connection interval of adjacent stations.

[0053] It is worth noting that the above data are nominal values, but the power and equipment costs of substations of different levels are different, so the It is not convenient to directly judge the operating risks of all substations on a single graph. Therefore, experts can select a substation with a moderate risk value from the substations of the same level within the management scope as the benchmark value, and then calculate the corresponding risk per unit value based on the initial risk value of the overall operation of the current substation and the risk benchmark value, and use the risk per unit value as the overall operation risk value of the current substation. Specifically, the calculation formula for the risk per unit value of the overall operation of the current substation is expressed as: ; In the formula, Indicates the current The risk level per unit of the overall operation of the station is It indicates the risk benchmark value selected by experts among substations of the same level.

[0054] Similarly, the overall operating risk value of each substation can be determined successively. In the actual application process, the master station will centrally display the risk level of each substation under the current working conditions online. In other words, whenever the substation has an interval for maintenance or other work, the master station can scan and calculate the risk value of each substation within the management scope through the above method.

[0055] Furthermore, after determining the risk per unit value of each substation within the management scope, the operation strategy and mode can be determined for each substation's risk per unit value, and a strategy table can be formed, so as to facilitate the actual situation on site and take measures online by comparing the strategy table. If the risk value of a substation is too high under the current maintenance state, the maintenance will be stopped directly to restore power supply or change the operation mode. Through advance discussion by experts, different preset measures are taken for different risk values ​​of different substations and placed in the system, so that the system can quickly take correct measures to solve the problem. If the risk per unit value of the substation is lower than 1, the dispatcher can be reminded to arrange single-interval maintenance and renovation projects at any time. If the risk per unit value of the substation is not lower than 1, the dispatcher is reminded that if renovation and maintenance are to be carried out, certain measures need to be taken to reduce the risk value before proceeding; if the risk per unit value during the renovation is greater than 1.5, the dispatcher needs to be reminded to pay attention and take certain measures to reduce the risk value, such as stopping the renovation as soon as possible or using other power sources to reduce the load of the station; if the risk per unit value of the substation during normal operation is greater than 2, the dispatcher is reminded to pay attention and take corresponding measures to reduce its risk value as soon as possible.

[0056] Example 3 refer to Figure 4 Based on Example 2, this example also has the following design.

[0057] Compared with the exhaustive method, although the time for calculating the risk value in Example 2 is greatly shortened, if the site requires an online scan of the site conditions, updating the risk value of the substation, finding the intervals with a higher risk of further failures and the corresponding substations that need attention in a cycle of 5 minutes, then the above algorithm may be difficult to meet the requirements of online evaluation when faced with a large number of sites, a large number of intervals, and a large number of possible failures due to the large amount of calculation content and a long time.

[0058] Therefore, this embodiment will classify and grade each substation according to the risk per unit value of each substation after status evaluation. For a substation with a low risk value, that is, the risk per unit value of the substation is within the preset first-level risk range, , its data can be scanned and calculated once an hour, and the original data can be kept unchanged for the rest of the time; for substations with moderate risk values, that is, if the risk degree per unit value of the substation is within the preset secondary risk range, , its data can be scanned and calculated once every half an hour; for substations with larger risk values, that is, the risk level per unit value of the substation is within the preset three-level risk range, The data can be scanned and calculated once every ten minutes; for substations with large risk values, that is, the risk level per unit value of the substation is within the preset three-level risk range, Its data can be scanned and calculated once every five minutes.

[0059] When the system operating conditions change, the brainstorming algorithm is immediately used again to find the fault with the greatest impact under the current conditions, and all sites and intervals are re-assigned, new risk values ​​are updated, and it is determined whether special attention is needed.

[0060] In addition, in actual application, the scanning times of the above-mentioned substations corresponding to different risk values ​​should be staggered to ensure that the system always has sufficient computing power to perform online risk assessment at a faster speed, so that the data can be circulated online, the data source is reliable and simple, and the results are clear.

[0061] In the actual application of this embodiment, when the state of some of the intervals of the substations changes due to failures, maintenance, etc., no matter how many intervals are shut down, the substation is regarded as N-1 state (i.e., the initial single interval fault state); then the brainstorming algorithm finds out the fault that has the greatest impact on the system after comprehensively considering the possibility and harm of occurrence under the current situation, and regards the fault state as N-1-n state (n can be 1 or 2, and n in this embodiment is preferably set to 1), and calculates the risk value of each substation in this state, so as to find out several substations with higher risk values ​​in this state, and formulates its strategy table in advance for these substations and corresponding intervals with higher risk values ​​in this state. Finally, considering the requirements of online functions for timeliness, a reasonable allocation arrangement is made for the update time of the data, so as to ensure that online safety assessment can be achieved. By combining the above processes, online safety risk assessment can be performed on the power system within the jurisdiction, which not only effectively improves the efficiency of system construction and operation, but also greatly enhances the applicability of the system.

[0062] Example 4 Based on the same inventive concept as Embodiment 1, 2 or 3, this embodiment introduces a substation safety risk assessment device considering interval power outages, which includes: A historical interval fault acquisition module is configured to acquire a historical interval fault event set causing a fault disturbance in the integrated substation system; A secondary fault interval determination module is configured to determine, based on a brainstorming optimization algorithm, from the historical interval fault event set the historical interval fault event with the greatest impact on the integrated substation system; An operation data acquisition module is configured to acquire system operation data corresponding to a historical interval fault event with the greatest impact on the integrated substation system that occurs in parallel with a known fault interval or a transformation interval during a power outage; In addition, the substation risk assessment module is configured to calculate the power outage risk and equipment risk of the remaining operating intervals in each substation based on the system operation data, and then determine the overall operation risk value of each substation within the system management scope based on the power outage risk and equipment risk of the remaining operating intervals in each substation.

[0063] Combination Figures 1 to 4 The substation safety risk assessment device considering intermittent power outages can execute the substation safety risk assessment method considering intermittent power outages introduced in the above-mentioned embodiment 1, 2 or 3, and the specific functional implementation of each functional module will not be repeated.

[0064] Example 5 This embodiment introduces a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the substation safety risk assessment method considering interval power outages as described in Embodiment 1, 2 or 3 are implemented.

[0065] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0066] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the process in the flowchart. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0067] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0068] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A substation safety risk assessment method considering interval power outages, characterized in that: include: Obtain a historical interval fault event set causing a fault disturbance in the integrated substation system; Based on a brainstorming optimization algorithm, determining the historical interval fault event with the greatest impact on the integrated substation system from the historical interval fault event set; Obtain system operation data corresponding to the historical interval fault event with the greatest impact on the integrated substation system that occurs in parallel with the known fault interval or the transformation interval during the power outage; According to the system operation data, the power outage risk and equipment risk of the remaining operation intervals in each substation are calculated, and then based on the power outage risk and equipment risk of the remaining operation intervals in each substation, the overall operation risk value of each substation within the system management scope is determined.

2. The substation safety risk assessment method considering interval power outages according to claim 1 is characterized in that: The power outage risks of the remaining operating intervals in each substation include: a first power outage risk corresponding to a power outage of an operating interval caused by a known fault interval or a modified interval in the substation during a power outage, and a second power outage risk corresponding to a power outage of a circuit breaker interval at a higher level due to a failure of the circuit breaker in the operating interval to cut off power under a fault; The calculation formula of the first power outage risk is expressed as: ； In the formula, Indicates that a known fault bay or modified bay in the substation causes a power outage in the operating bay during the power outage The corresponding first power outage risk, Indicates the running interval The outgoing line load factor, Indicates the price of electricity per kilowatt-hour. Indicates the interval of power outage for maintenance Planned outage interval with simulated secondary failure After a fault occurs, the running interval The probability of power outage due to fault, Indicates the interval The time of power outage, Indicates the running interval Power outage recovery time Indicates the running interval exist arrive Transmission power during the time period; The calculation formula of the second power outage risk is expressed as: ； In the formula, Indicates the running interval The second power outage risk corresponding to the power outage of the upper-level circuit breaker due to the failure of the circuit breaker to cut off the power under fault conditions, It indicates the accident rate of circuit breaker transformer according to the working time. Indicates the interval The time of power outage, Indicates the interval Estimated time for power outage restoration, Indicates the running interval The power predicted by the power curve during the power outage period of the previous power outage range, Indicates the running interval The operating time of the circuit breaker.

3. The substation safety risk assessment method considering interval power outages according to claim 2 is characterized in that: If the load carried by the outgoing line is only from the operating interval Power supply, then the running interval The outgoing line load factor is 1; If the load carried by the outgoing line is supplied by multiple intervals, the operating interval The outgoing line load factor is 0.

4. The substation safety risk assessment method considering interval power outages according to claim 2 or 3 is characterized in that: The equipment risk of the remaining operating intervals in each substation is calculated by the following formula: ； In the formula, Indicates the running interval Equipment risks, Indicates the running interval Overall primary equipment cost.

5. The substation safety risk assessment method considering interval power outages according to claim 4 is characterized in that: Based on the power outage risk and equipment risk of the remaining operating intervals in each substation, the overall operating risk value of each substation within the system management scope is determined, including: According to the power outage risk and equipment risk of each operating interval, the overall operating risk value of each operating interval is calculated; Considering the overall operation risk values ​​of all operation intervals in each substation and the overall operation risk values ​​of the intervals directly connected to the adjacent stations of each substation, the initial overall operation risk value of each substation is determined; Obtaining a preset risk value at the same level corresponding to each substation within the system management scope, and using the preset risk value as a risk reference value corresponding to each substation; According to the initial overall operation risk value of each substation and the risk reference value corresponding to each substation, the risk per unit value corresponding to each substation is calculated, and the risk per unit value is used as the overall operation risk value of each substation.

6. The substation safety risk assessment method considering interval power outages according to claim 5 is characterized in that: According to the power outage risk and equipment risk of each operating interval, the overall operating risk value of each operating interval is calculated and expressed as: ； In the formula, Indicates the overall operation risk value corresponding to the operation interval, and Represent coefficients respectively, and satisfy ; Considering the overall operation risk value of all operating intervals in each substation and the overall operation risk value of the intervals directly connected to the adjacent stations of each substation, the initial overall operation risk value of each substation is determined, which is expressed as: ； In the formula, represents the initial overall operation risk value of each substation, Indicates the number of operating bays in the substation, Indicates the overall operation risk value of the direct connection interval between adjacent stations; Considering the substation with interval power outage, the risk level corresponding to each substation is calculated based on the initial overall operation risk value of each substation and the risk reference value corresponding to each substation, which is expressed as: ； In the formula, Indicates the risk level corresponding to each substation. It indicates the risk benchmark value selected by experts among substations of the same level.

7. The substation safety risk assessment method considering interval power outages according to claim 6 is characterized in that: Based on the brainstorming optimization algorithm, the historical interval fault events with the greatest impact on the integrated substation system are determined from the historical interval fault event set, including: Based on the historical interval failure event set, generating an initial population and setting algorithm parameters; The initial population is clustered using a k-means clustering algorithm, and then the individuals contained in each class are sorted according to the fitness value, and the individual with the largest fitness is selected as the cluster center of the class; Based on the brainstorming algorithm, a random number is generated, and the corresponding operation type is determined according to the value of the random number; if the random number is less than or equal to the first threshold, an operation of selecting a random individual is performed, and a new individual is generated by adding random perturbations; if the random number is between the first threshold and the second threshold, an operation of selecting the center of a cluster or a random individual is performed, and a new individual is generated by adding random perturbations; if the random number is greater than or equal to the second threshold, an operation of selecting the centers of two clusters or random individuals is performed, the two individuals or cluster centers are merged, and a new individual is generated by adding random perturbations; Taking the risk per unit value as the fitness value, the new individual is compared with the cluster center, and the individual with a high fitness value is selected to enter the next generation; The above clustering, individual updating and selection operations are repeated until the preset number of iterations is reached. After the iteration is completed, the optimal solution corresponding to the bay fault event that has the greatest impact on the integrated substation system is output.

8. The substation safety risk assessment method considering interval power outages according to claim 7 is characterized in that: According to the risk level per unit value corresponding to each substation, the online refresh time of the status valuation is arranged, including: If the risk per unit value of the substation is within the preset level 1 risk range, the scanning interval of the corresponding operating data is set to one hour; if the risk per unit value of the substation is within the preset level 2 risk range, the scanning interval of the corresponding operating data is set to half an hour; if the risk per unit value of the substation is within the preset level 3 risk range, the scanning interval of the corresponding operating data is set to ten minutes; if the risk per unit value of the substation is within the preset level 4 risk range, the scanning interval of the corresponding operating data is set to five minutes.

9. A substation safety risk assessment device considering interval power outages, characterized in that: include: A historical interval fault acquisition module is configured to acquire a historical interval fault event set causing a fault disturbance in the integrated substation system; A secondary fault interval determination module is configured to determine, based on a brainstorming optimization algorithm, from the historical interval fault event set the historical interval fault event with the greatest impact on the integrated substation system; An operation data acquisition module is configured to acquire system operation data corresponding to a historical interval fault event with the greatest impact on the integrated substation system that occurs in parallel with a known fault interval or a transformation interval during a power outage; In addition, the substation risk assessment module is configured to calculate the power outage risk and equipment risk of the remaining operating intervals in each substation based on the system operation data, and then determine the overall operation risk value of each substation within the system management scope based on the power outage risk and equipment risk of the remaining operating intervals in each substation.

10. 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 substation safety risk assessment method considering interval power outages described in any one of claims 1 to 8 are implemented.

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