A power grid risk assessment method, device and medium based on situation awareness

Abstract

The application provides a power grid risk assessment method and device based on situation awareness, and a medium, relates to the technical field of risk assessment, and comprises determining the evaluation nodes and voltage state characteristics corresponding to each switching action; according to the response effect of the switching action and the influence of the switching action on the voltage state characteristics of each evaluation node, the standard single-action influence quantity of each switching action is calculated; according to the reactive power compensation demand of each evaluation node, a candidate switching action combination is determined, the combination reference influence quantity and the combination actual influence quantity of each candidate switching action combination are calculated, and an optimal switching combination is obtained; the single switching action and the optimal switching combination that meet the reactive power compensation demand are used as candidate control schemes, and whether a risk signal is generated is determined according to the comparison result of the influence quantity and the preset influence quantity threshold, the application can evaluate the effectiveness of the current control scheme according to the voltage influence generated by the actual switching of the shunt capacitor, and improve the accuracy of the distribution network risk assessment.

Description

Technical Field

[0001] This invention relates to the field of risk assessment technology, specifically to a power grid risk assessment method, equipment, and medium based on situational awareness. Background Technology

[0002] As the operation mode of the distribution network continues to change, node voltage is easily affected by factors such as load fluctuations, reactive power changes, and changes in network operating status. When the node voltage deviates from the target operating range, reactive power compensation is usually carried out by switching parallel capacitors to change the reactive power distribution in the distribution network and regulate the node voltage. Existing technologies typically determine the required reactive power compensation capacity based on the current voltage deviation at the node and select corresponding switching actions based on the rated capacity of the parallel capacitors. However, the fact that the rated reactive power compensation capacity of the parallel capacitors can meet the requirements does not necessarily mean that the actual switching will produce the corresponding voltage control effect. Due to differences in the installation location of the parallel capacitors, the current operating state of the distribution network, and the actual response of the equipment, different switching actions with the same reactive power compensation capacity may have different degrees of voltage impact on the target node. In particular, when multiple parallel capacitors are switched in combination, the actual comprehensive voltage impact formed by the simultaneous operation of each capacitor may differ from the superposition of the effects when each capacitor operates individually. Therefore, selecting a switching scheme solely based on the reactive power compensation capacity makes it difficult to determine whether the currently available switching actions truly have the actual regulatory capability to meet the current voltage control requirements. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: A power grid risk assessment method based on situational awareness, the method comprising: S1: Obtain the operating status data and parallel capacitor switching action records of the target distribution network area, determine the evaluation node corresponding to each switching action, and obtain the voltage operation data of each evaluation node before and after the switching action to determine the voltage state characteristics corresponding to each evaluation node. S2: For each parallel capacitor switching action, determine the response effect of the switching action, and calculate the standard single-action influence of each switching action based on the influence of the switching action on the voltage state characteristics; S3: Determine candidate switching action combinations based on the reactive power compensation requirements of each evaluation node, obtain the combined baseline influence of each candidate switching action combination, calculate the combined actual influence, determine the combined synergistic influence based on the difference between the combined actual influence and the combined baseline influence, and obtain the preferred switching combination. S4: For the reactive power compensation requirements of each evaluation node, the individual switching actions and preferred switching combinations that meet the reactive power compensation requirements are taken as candidate control schemes. Based on the comparison results of the standard single action influence or combined actual influence of each candidate control scheme with the preset influence threshold, it is determined whether to generate a risk signal.

[0004] Furthermore, acquire operational status data and parallel capacitor switching operation records for the target distribution network area, including: Using the installation location of the parallel capacitor corresponding to the switching action as the reference location for determining the influence range, multiple nodes that are electrically related to the installation location and within a preset electrical distance range are determined according to the distribution network topology, and these multiple nodes are used as the evaluation nodes corresponding to the switching action. Obtain the voltage amplitude of each evaluation node within the first time window before the issuance of the switching command for the switching action, and use it as the voltage value before the action; Obtain the voltage amplitude of each evaluation node within the second time window after the completion of the switching action, and use it as the voltage value after the action.

[0005] Furthermore, the voltage state characteristics corresponding to each evaluation node are determined, including: Obtain the rated voltage value of each evaluation node. For each evaluation node, calculate the voltage deviation rate before action based on the voltage value before action and the rated voltage value; calculate the voltage deviation rate after action based on the voltage value after action and the rated voltage value; calculate the voltage change rate before action based on the voltage value before action and the sampling interval; calculate the voltage change rate after action based on the voltage value after action and the sampling interval. The voltage values ​​before the action, the voltage deviation rate before the action, the voltage change rate before the action, the voltage values ​​after the action, the voltage deviation rate after the action, and the voltage change rate after the action of each evaluation node are integrated to form the voltage state characteristics of each evaluation node corresponding to the switching action.

[0006] Furthermore, the response of the throwing and cutting action is determined, including: The time of the issuance of the switching command and the time of completion of the switching action are obtained, and the time interval between the completion time of the switching action and the issuance time of the switching command is determined as the actual action response time of the switching action; Based on the inherent motion characteristics corresponding to the throwing and cutting motion, determine the baseline motion response time of the throwing and cutting motion; The actual action response time is compared with the baseline action response time; If the actual action response time is less than or equal to the baseline action response time, the response is determined to be normal. If the actual action response time is greater than the baseline action response time, the response is determined to be delayed, and a response delay correction coefficient is determined.

[0007] Furthermore, based on the impact of switching actions on voltage state characteristics, the standard single-action impact of each switching action is calculated, including: For each evaluation node, the voltage value without switching action is predicted based on the voltage change trend in the first time window before the action. The difference between the measured voltage value and the predicted value in the second time window after the action is used as the voltage influence of the switching action on each voltage state characteristic. Based on the comparison between the voltage deviation rate after the action of each evaluation node and the target voltage deviation rate, the effect achievement factor of the switching action on each evaluation node is determined. The voltage impact of each evaluation node, the effect achievement factor, and the response delay correction coefficient are combined to calculate the single-action impact of the switching action on each voltage state characteristic. Obtain the historical single-action impact value record under the reactive power compensation requirement corresponding to the switching action, add the current single-action impact value to the historical single-action impact value record, calculate the average value of the updated single-action impact value, and use it as the standard single-action impact value of the switching action under the reactive power compensation requirement.

[0008] Furthermore, based on the comparison between the voltage deviation rate after the action of each evaluation node and the target voltage deviation rate, the effect achievement factor of the switching action on each evaluation node is determined, including: Obtain the preset target voltage deviation rate for each evaluation node, and compare the absolute value of the voltage deviation rate after the action of each evaluation node with the target voltage deviation rate. If the absolute value of the voltage deviation rate after the action is less than or equal to the target voltage deviation rate, it is determined that the switching action has the expected effect on the voltage control of each evaluation node, and the effect achievement factor is recorded as 1. If the absolute value of the voltage deviation rate after the action is greater than the target voltage deviation rate, it will be determined that the voltage control effect of the switching action on each evaluation node has not met expectations, and the ratio of the target voltage deviation rate to the absolute value of the voltage deviation rate after the action will be used as the effect achievement factor.

[0009] Furthermore, the combined synergistic effect is determined based on the difference between the combined actual effect and the combined baseline effect, including: Based on the reactive power compensation requirements of each evaluation node, multiple candidate switching action combinations that meet the same reactive power compensation requirements are determined from the available parallel capacitors. For each candidate switching action combination, the standard single action influence of each parallel capacitor in each candidate switching action combination is superimposed according to the evaluation node to obtain the combined benchmark influence of each evaluation node corresponding to each candidate switching action combination. For each candidate switching action combination, the voltage impact is determined based on the voltage state characteristics of each candidate switching action combination at each evaluation node, and the actual impact of the combination at each evaluation node is obtained by combining the corresponding effect achievement factor and response delay correction coefficient. The combined synergistic impact of each evaluation node is calculated by subtracting the actual combined impact from the corresponding combined baseline impact.

[0010] Further, determine whether a risk signal is generated, including: Compare the standard single-action impact or combined actual impact of each candidate control scheme with the preset impact threshold. If there is a candidate control scheme that reaches the preset impact threshold, no risk signal is generated; If no candidate control scheme reaches the preset impact threshold, a risk signal is generated.

[0011] Furthermore, an electronic device includes a processor and a memory, wherein the memory stores computer program instructions.

[0012] Furthermore, a computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of a situational awareness-based power grid risk assessment method as described above.

[0013] This invention provides a power grid risk assessment method, device, and medium based on situational awareness. It has the following beneficial effects: This invention determines the impact of a standard single action by analyzing the actual voltage effect, action response, and control effect of switching actions on each evaluation node, and further determines the combined synergistic impact of switching combinations. This quantifies the actual voltage regulation capability of different switching actions and combinations, improving the accuracy of switching combination selection.

[0014] This invention uses individual switching actions and preferred switching combinations that meet reactive power compensation requirements as candidate control schemes, and determines whether to generate a risk signal based on the comparison between their impact amplitude and a preset impact threshold. This enables the identification of operating states where reactive power compensation capacity is met but actual voltage regulation capability is insufficient, thereby improving the pertinence of power grid risk assessment. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a power grid risk assessment method based on situational awareness according to the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1, such as Figure 1 As shown, a power grid risk assessment method based on situational awareness is proposed, the method comprising: S1: Obtain the operating status data and parallel capacitor switching action records of the target distribution network area, determine the evaluation node corresponding to each switching action, and obtain the voltage operation data of each evaluation node before and after the switching action to determine the voltage state characteristics corresponding to each evaluation node. S2: For each parallel capacitor switching action, determine the response effect of the switching action, and calculate the standard single-action influence of each switching action based on the influence of the switching action on the voltage state characteristics; S3: Determine candidate switching action combinations based on the reactive power compensation requirements of each evaluation node, obtain the combined baseline influence of each candidate switching action combination, calculate the combined actual influence, determine the combined synergistic influence based on the difference between the combined actual influence and the combined baseline influence, and obtain the preferred switching combination. S4: For the reactive power compensation requirements of each evaluation node, the individual switching actions and preferred switching combinations that meet the reactive power compensation requirements are taken as candidate control schemes. Based on the comparison results of the standard single action influence or combined actual influence of each candidate control scheme with the preset influence threshold, it is determined whether to generate a risk signal.

[0018] Acquire operational status data and parallel capacitor switching records for the target distribution network area, including: Using the installation location of the parallel capacitor corresponding to the switching action as the reference location for determining the influence range, multiple nodes that are electrically related to the installation location and within a preset electrical distance range are determined according to the distribution network topology, and these multiple nodes are used as the evaluation nodes corresponding to the switching action. Obtain the voltage amplitude of each evaluation node within the first time window before the issuance of the switching command for the switching action, and use it as the voltage value before the action; Obtain the voltage amplitude of each evaluation node within the second time window after the completion of the switching action, and use it as the voltage value after the action.

[0019] It should be noted that the switching of parallel capacitors in the distribution network is usually decided and issued by the automatic voltage control system (AVC system) based on the voltage monitoring values ​​of each node and the preset voltage operating range, or by the dispatcher issuing control commands based on the operation requirements of the distribution network.

[0020] In this embodiment, the evaluation node is used to evaluate the impact of parallel capacitor switching actions on the voltage state at different locations in the distribution network, and is not limited to the installation node of the parallel capacitor. For any switching action, the installation location of the parallel capacitor corresponding to the switching action is used as the reference location for determining the impact range. The nodes that are electrically associated with the installation location are determined according to the current topology of the target distribution network, and the nodes within the preset electrical distance range are selected as evaluation nodes according to the electrical distance between the nodes and the installation location, so that the evaluation node covers the area where the switching action may have a significant voltage impact.

[0021] The electrical association is used to characterize the electrical transmission path formed by the distribution network topology and line connection relationship between the node and the installation location, and the electrical distance is used to characterize the electrical propagation distance when the voltage influence of the switching action is transmitted from the installation location of the parallel capacitor to other nodes of the distribution network.

[0022] In the actual operation of the distribution network, the switching command for parallel capacitors can be automatically generated by the automatic voltage control system based on the node voltage operating status, or it can be manually issued by the dispatcher based on the distribution network operation requirements. This invention does not limit the specific generation method of the switching command. When the voltage of a certain evaluation node deviates from the rated value by more than the preset start threshold, the reactive power compensation requirement required to reach the target voltage is calculated based on the difference between the current voltage and the target voltage of the node and the system short-circuit capacity of the node. Then, a single or multiple capacitor groups that meet the compensation capacity are selected from the available capacitor groups near the node, and the switching command is issued.

[0023] It should be noted that the selection process is based on theoretical calculations of an ideal power grid model. These theoretical calculations typically use simplified sensitivity formulas or power flow calculations to provide the theoretical expected voltage change for switching combinations. However, the actual operating state of the distribution network is always in dynamic change, resulting in a non-negligible deviation between the theoretical expected value and the actual voltage change.

[0024] In some embodiments of the present invention, when a switching command for any parallel capacitor is issued, the system records the capacitor device number and execution time corresponding to the switching action. When the parallel capacitor is connected to the distribution network, its reactive power injection will change the reactive power distribution of the network, thereby causing changes in the voltage of each node. This voltage change has significant regional characteristics; the closer to the capacitor installation node, the more significant the voltage change, and the voltage change rapidly decays with the increase of electrical distance. Therefore, in order to comprehensively record the impact of a switching action on the voltage state at different locations in the distribution network, it is necessary to determine multiple evaluation nodes within the influence range of the switching action, rather than focusing only on the installation location of the parallel capacitor. Specifically, nodes that are electrically associated with the installation location are determined according to the current topology of the target distribution network, and the nodes within the preset electrical distance range are selected as evaluation nodes based on the electrical distance between each node and the installation location. The preset electrical distance threshold is preset based on the voltage level, line impedance parameters, and rated capacity of the capacitor in the distribution network, and can be determined by those skilled in the art based on the actual distribution network parameters.

[0025] After determining the evaluation nodes, the voltage values ​​before and after the action are obtained for each evaluation node. The voltage value before the action refers to the voltage amplitude of each evaluation node in steady-state operation before the issuance of the switching command. To ensure that the obtained voltage data can truly reflect the steady-state operation of the distribution network before the switching action is executed, a first time window is defined as a time window before the issuance of the switching command. The end of the first time window is immediately adjacent to the issuance of the switching command. The time window is extended forward by a preset length from the issuance of the switching command to ensure that the voltage sampling data within the first time window is all before the issuance of the switching command, thereby avoiding the impact of the switching action on the voltage data before the action.

[0026] The voltage value after the action refers to the voltage amplitude of each evaluation node after reaching a new steady state following the completion of the switching action. To ensure that the acquired voltage data can accurately reflect the new steady-state voltage value reached by the distribution network after the switching action is completed, a second time window is defined as a time window after the completion of the switching action. The starting position of the second time window is close to the completion time of the switching action, and a preset length is extended backward from the completion time of the switching action, so that the voltage sampling data within the second time window can be used to characterize the voltage state after the switching action is completed.

[0027] It should be noted that the lengths of the first and second time windows, as well as the electrical distance threshold, can all be preset and adjusted by those skilled in the art based on the actual parameters of the target distribution network. The length of the first time window is a segment of steady-state data prior to the issuance of the switching command, and its specific value depends on the natural fluctuation period of the grid voltage, which can be set by those skilled in the art based on the actual operating characteristics of the distribution network. The length of the second time window is a segment of data after the switching action is completed and the voltage has entered a new steady state, and its specific value depends on the typical time for the voltage to transition from transient to steady state after capacitor switching, which can be set by those skilled in the art based on the actual response characteristics of the distribution network. The electrical distance threshold mainly depends on the voltage level of the distribution network, line impedance parameters, and the rated capacity of the capacitors, and can be set based on the actual topology and operating experience of the distribution network. The specific values ​​of the above parameters can be flexibly determined by those skilled in the art based on the actual application scenario, without affecting the implementation of the technical solution of this invention.

[0028] Determine the voltage state characteristics corresponding to each evaluation node, including: Obtain the rated voltage value of each evaluation node. For each evaluation node, calculate the voltage deviation rate before action based on the voltage value before action and the rated voltage value; calculate the voltage deviation rate after action based on the voltage value after action and the rated voltage value; calculate the voltage change rate before action based on the voltage value before action and the sampling interval; calculate the voltage change rate after action based on the voltage value after action and the sampling interval. The voltage values ​​before the action, the voltage deviation rate before the action, the voltage change rate before the action, the voltage values ​​after the action, the voltage deviation rate after the action, and the voltage change rate after the action of each evaluation node are integrated to form the voltage state characteristics of each evaluation node corresponding to the switching action.

[0029] In this embodiment, in order to comprehensively depict the voltage state of each evaluation node before and after the switching action, voltage state features of multiple dimensions are extracted from the node voltage operation status data. Specifically, the rated voltage value of each evaluation node is obtained. The rated voltage value is the standard voltage value of each voltage level determined in the distribution network planning and design stage. For example, the rated voltage of a node in a 10kV distribution network is 10kV. This value is stored in the parameter management database of the distribution network and can be read directly.

[0030] For each evaluation node, its voltage deviation rate is calculated separately. The voltage deviation rate measures the degree to which the current voltage of the node deviates from the rated voltage value and is an important indicator for judging the risk of voltage exceeding the limit. Specifically, the voltage deviation rate before action is calculated based on the voltage value of the evaluation node before action and the rated voltage value. The calculation method is: divide the difference between the voltage value before action and the rated voltage value by the rated voltage value to obtain the voltage deviation rate before action. The voltage deviation rate before action reflects the degree of voltage deviation of the evaluation node under normal operating conditions before the switching action is executed. Similarly, the voltage deviation rate after action is calculated based on the voltage value of the evaluation node after action and the rated voltage value. The calculation method is: divide the difference between the voltage value after action and the rated voltage value by the rated voltage value to obtain the voltage deviation rate after action. This value reflects the degree of voltage deviation of the evaluation node under the new steady state after the switching action is completed.

[0031] For each evaluation node, its voltage change rate is calculated. The voltage change rate measures how quickly the node's voltage changes per unit time and is an important parameter reflecting voltage stability and dynamic response characteristics. Specifically, based on the evaluation node's voltage value before the action and the sampling interval, the voltage change rate before the action is calculated as follows: obtain the voltage amplitude of the evaluation node at adjacent sampling moments within the first time window, calculate the difference between the voltage amplitudes at adjacent sampling moments, and divide this difference by the sampling interval to obtain the voltage change rate before the action. This value reflects the natural change trend of the evaluation node's voltage before the switching action is executed. Similarly, based on the evaluation node's voltage value after the action and the sampling interval, the voltage change rate after the action is calculated as follows: obtain the voltage amplitude of the evaluation node at adjacent sampling moments within the second time window, calculate the difference between the voltage amplitudes at adjacent sampling moments, and divide this difference by the sampling interval to obtain the voltage change rate after the action. This value reflects the voltage change trend of the evaluation node in the new steady state after the switching action is completed.

[0032] In this embodiment, the voltage deviation rate before the action is the key basis for determining the triggering of the switching action and the subsequent combination mode. That is, based on the degree of deviation between the current evaluation node voltage and the rated voltage, it is determined whether the capacitor needs to be connected or disconnected, and how much reactive power compensation is required. The capacity requirement of the switching action is determined by the voltage deviation rate before the action combined with the short-circuit capacity of the node. Specifically, the voltage rise required to reach the target voltage is calculated based on the voltage deviation rate before the action, and then the voltage rise is converted into the required reactive power compensation requirement based on the short-circuit capacity of the evaluation node. For example, if the rated voltage of a 10kV node is 10kV, the voltage before the action is 9.4kV, and the target voltage is 9.8kV, then the required voltage rise is 0.4kV. The corresponding reactive power compensation requirement is determined based on the short-circuit capacity of the node and the preset voltage-reactive power relationship.

[0033] After determining the required compensation capacity, select from all available capacitor banks within the preset electrical distance range of the evaluation node; for example, if the required compensation capacity is 5Mvar, and the available capacitor banks near the node include three groups of 2Mvar, 2Mvar, and 1Mvar, then a 2+2+1 combination method (total capacity 5Mvar) can be used; if there is one 5Mvar capacitor bank near the node, then a single-group switching method (capacity 5Mvar) can be used.

[0034] Determine the response of the throwing and cutting motion, including: The time of the issuance of the switching command and the time of completion of the switching action are obtained, and the time interval between the completion time of the switching action and the issuance time of the switching command is determined as the actual action response time of the switching action; Based on the inherent motion characteristics corresponding to the throwing and cutting motion, determine the baseline motion response time of the throwing and cutting motion; The actual action response time is compared with the baseline action response time; If the actual action response time is less than or equal to the baseline action response time, the response is determined to be normal. If the actual action response time is greater than the baseline action response time, the response is determined to be delayed, and a response delay correction coefficient is determined.

[0035] In this embodiment, the response of the switching action refers to the characteristics of the action process from the moment the switching command is issued (i.e., the end of the first time window) to the moment the capacitor is actually connected to the power grid (i.e., the beginning of the second time window). This process reflects the physical action quality of the circuit breaker or contactor from receiving the command to completing the electrical connection. As the execution element for capacitor switching, the operating speed of the circuit breaker or contactor directly affects the execution quality of the switching action. By monitoring the actual action response time of the switching action and comparing it with the reference action response time, the execution quality of the switching action can be evaluated.

[0036] In this embodiment, the time of issuance of the switching command and the time of completion of the switching action are obtained, and the time interval between the time of completion of the switching action and the time of issuance of the switching command is determined as the actual action response time of the switching action.

[0037] It should be noted that the reference action response time is determined by the inherent operating characteristics of the circuit breaker or switchgear associated with the capacitor bank corresponding to the switching action. After receiving the action command, the circuit breaker or switchgear needs to go through a series of physical processes such as the start of the operating mechanism, mechanical transmission, and contact movement to complete the electrical connection. The inherent time required for this process is determined by the design parameters and mechanical structure of the equipment. Different types and models of circuit breakers have different inherent operating characteristics.

[0038] In an alternative embodiment of the present invention, the reference action response time can be determined by one of the following methods: it can be determined according to the ex-factory technical parameters of the circuit breaker or switching equipment matched with the capacitor bank. Equipment manufacturers usually indicate the inherent action time range or typical value of this model of circuit breaker in the technical manual when leaving the factory, and this typical value can be directly used as the reference action response time; it can be determined according to the on-site action characteristic test results, and the inherent action time of the circuit breaker is directly measured by carrying out a opening and closing action characteristic test on the circuit breaker on site with a circuit breaker action characteristic tester.

[0039] By comparing the actual action response time with the reference action response time: if the actual action response time is less than or equal to the reference action response time, it indicates that the action speed of the circuit breaker during this switching action meets or is better than its normal level, and the response is determined to be normal; if the actual action response time is greater than the reference action response time, it indicates that the action speed of the circuit breaker during this switching action is slower than its normal level, and abnormal conditions such as mechanism jamming, coil aging or mechanical wear may exist, and the response is determined to be delayed.

[0040] When the response is determined to be delayed, a response delay correction coefficient is further determined according to the ratio of the reference action response time to the actual action response time, wherein the value range of the ratio is between 0 and 1. When the actual action response time is greater than the reference action response time, the ratio is less than 1, and the farther the actual action response time deviates from the reference, the smaller the ratio and the larger the correction amplitude; when the response is determined to be normal, the response delay correction coefficient is 1.

[0041] According to the influence of the switching action on voltage state characteristics, calculate the standard single-action influence quantity of each switching action, including: For each evaluation node, predict the voltage value when there is no switching action according to the voltage change trend in the first time window before the action, and take the difference between the measured voltage value in the second time window after the action and the predicted value as the voltage influence quantity of the switching action on each voltage state characteristic; Determine the effect achievement factor of the switching action on each evaluation node according to the comparison result between the post-action voltage deviation rate of each evaluation node and the target voltage deviation rate; Perform comprehensive calculation on the voltage influence quantity, the effect achievement factor and the response delay correction coefficient of each evaluation node to obtain the current single-action influence quantity of the switching action on each voltage state characteristic; Obtain the historical single-action influence quantity record under the reactive power compensation demand corresponding to the switching action, add the current single-action influence quantity to the historical single-action influence quantity record, calculate the updated average value of single-action influence quantity, and use it as the standard single-action influence quantity of the switching action under the reactive power compensation demand.

[0042] Based on the comparison between the voltage deviation rate after the action and the target voltage deviation rate at each evaluation node, the achievement factor of the switching action for each evaluation node is determined, including: Obtain the preset target voltage deviation rate for each evaluation node, and compare the absolute value of the voltage deviation rate after the action of each evaluation node with the target voltage deviation rate. If the absolute value of the voltage deviation rate after the action is less than or equal to the target voltage deviation rate, it is determined that the switching action has the expected effect on the voltage control of each evaluation node, and the effect achievement factor is recorded as 1. If the absolute value of the voltage deviation rate after the action is greater than the target voltage deviation rate, it will be determined that the voltage control effect of the switching action on each evaluation node has not met expectations, and the ratio of the target voltage deviation rate to the absolute value of the voltage deviation rate after the action will be used as the effect achievement factor.

[0043] In this embodiment, based on the voltage impact of the switching action on each voltage state characteristic, the standard single-action impact of each switching action on each voltage state characteristic is calculated. The voltage impact is used to characterize the voltage change amplitude independently contributed by the switching action. The voltage impact is calculated as follows: for each evaluation node, the voltage amplitude at each sampling moment within the first time window before the action is arranged in chronological order to form a voltage time series before the action. The first time window is located before the switching command is issued, and its end is immediately adjacent to the execution time. The voltage data within the window is entirely collected before the capacitor is connected to the grid and is not affected by the switching action, only reflecting the natural voltage change trend caused by non-control factors such as load fluctuations and changes in renewable energy output. The least squares method is used to linearly fit the time series to obtain a trend line of voltage change over time.

[0044] The time corresponding to the end of the second time window is determined and denoted as T2. T2 is the last sampling time when the voltage enters a new steady state after the switching action is completed. At this time, the voltage has been completely stabilized and the data is representative. The fitted trend line is extended to time T2 to obtain the predicted voltage value of the evaluation node without the switching action, denoted as Vp. This predicted value represents the voltage level that each evaluation node should have at time T2 under the condition that no switching action has occurred. It is obtained entirely by extrapolation based on the natural change trend of the voltage before the action, without introducing any information about the switching action. Therefore, it can serve as an independent reference benchmark for measuring the true contribution of the switching action.

[0045] Obtain the measured voltage value of the evaluation node at time T2, denoted as Vm. This measured value is taken from the end of the second time window after the switching action is completed. At this time, the voltage has entered a new steady state and can represent the actual final voltage level after the switching action is completed.

[0046] Calculate the difference between the measured voltage value and the predicted voltage value, i.e. The voltage influence of the switching action on the characteristics of each voltage state is denoted as T2. The predicted voltage value and the measured voltage value are taken from the same time T2, which ensures that the voltage influence is compared on the same time section, the physical correspondence is clear, and the deviation caused by the misalignment of time points is avoided.

[0047] It should be noted that reactive power compensation demand is a scenario label for classifying the historical single-action impact records, which determines which historical record set the current switching action should belong to; reactive power compensation demand is calculated based on the voltage deviation rate before the action of each evaluation node to reach the target voltage, and then the voltage rise is converted into the required reactive power compensation demand based on the short-circuit capacity of the evaluation node.

[0048] In this embodiment, the effect achievement factor of the switching action on each evaluation node is determined based on the comparison between the voltage deviation rate after the action and the target voltage deviation rate. The effect achievement factor is used to measure whether the voltage deviation of each evaluation node has reached the expected control target after the switching action is completed. It is a key parameter for correcting the voltage effect dimension in the calculation of the single action influence. Specifically, it is implemented in the following way: Obtain the preset target voltage deviation rate for each evaluation node. The target voltage deviation rate refers to the maximum allowable deviation range of the voltage of each evaluation node from the rated voltage value after the switching action is completed. It is preset by those skilled in the art according to the voltage control requirements of the distribution network, for example, it can be set to ±2%. This value represents the allowable deviation range that the voltage control is expected to achieve.

[0049] The absolute value of the voltage deviation rate after each evaluation node's action is compared with the target voltage deviation rate. The reason for using absolute values ​​for comparison is that the voltage deviation rate itself has a positive or negative sign; a positive value indicates the voltage is higher than the rated value, and a negative value indicates the voltage is lower than the rated value. When determining whether the voltage meets the standard, the focus is on the magnitude of the deviation, not the direction of deviation. In other words, whether the voltage is too high or too low is equally important in determining whether the standard is met. Therefore, regardless of whether the voltage is too high or too low, its absolute value is uniformly compared with the target voltage deviation rate.

[0050] If the absolute value of the voltage deviation rate after the action is less than or equal to the target voltage deviation rate, it indicates that the voltage deviation of the evaluation node has been narrowed to the allowable range after the switching action is completed, and the switching effect has achieved the expected goal. At this time, the effect achievement factor is recorded as 1, and no amplification or reduction is performed.

[0051] If the absolute value of the voltage deviation rate after the action is greater than the target voltage deviation rate, it indicates that the voltage deviation of the evaluation node has not yet reached the expected target after the switching action is completed, and the switching effect has not been fully achieved. At this time, the ratio of the target voltage deviation rate to the absolute value of the voltage deviation rate after the action is used as the effect achievement factor. This ratio is less than 1, and the further the actual deviation rate deviates from the target, the smaller the ratio, and the greater the reduction in the impact of this single action.

[0052] It should be noted that the greater the actual voltage deviation deviates from the target deviation, the lower the degree of effectiveness of the switching action, and the smaller its contribution to the overall evaluation. By introducing the effectiveness achievement factor, the influence of a single action can reflect whether the switching action has truly solved the voltage deviation problem, rather than simply recording how much the voltage has changed.

[0053] The voltage impact, effect achievement factor, and response delay correction coefficient of each evaluation node are comprehensively calculated to obtain the single-action impact of the switching action on each voltage state characteristic. Specifically, the single-action impact is equal to the voltage impact multiplied by the effect achievement factor and the response delay correction coefficient. The voltage impact reflects the actual change in voltage caused by the switching action and is the base value. The effect achievement factor reflects whether the voltage after the switching achieves the expected target. If the target is achieved, it is not scaled; if the target is not achieved, it is reduced proportionally. The response delay correction coefficient reflects the execution quality of the switching action. If it is normal, it is not scaled; if there is a delay, it is reduced proportionally.

[0054] The historical single-action impact records of the switching action under the reactive power compensation demand are obtained. The historical single-action impact records are stored with the switching action and reactive power compensation demand as indexes. That is, the switching records of the same installation node and the same capacitor bank under the same reactive power compensation demand belong to the same set, and different reactive power compensation demands correspond to different historical record sets. For example, the single-action impact records of the capacitor bank under the 2Mvar demand belong to the "2Mvar" set, and the single-action impact records of the capacitor bank under the 5Mvar demand belong to the "5Mvar" set.

[0055] By adding the current single-action impact value obtained from this calculation to the corresponding historical single-action impact value record, the average value of the updated single-action impact value is calculated as the standard single-action impact value of the switching action under the reactive power compensation requirement. The standard single-action impact value represents the typical control capability of the switching action under the reactive power compensation requirement and is a stable value after smoothing multiple switching data.

[0056] The combined synergistic effect is determined based on the difference between the actual combined effect and the combined baseline effect, including: Based on the reactive power compensation requirements of each evaluation node, multiple candidate switching action combinations that meet the same reactive power compensation requirements are determined from the available parallel capacitors. For each candidate switching action combination, the standard single action influence of each parallel capacitor in each candidate switching action combination is superimposed according to the evaluation node to obtain the combined benchmark influence of each evaluation node corresponding to each candidate switching action combination. For each candidate switching action combination, the voltage impact is determined based on the voltage state characteristics of each candidate switching action combination at each evaluation node, and the actual impact of the combination at each evaluation node is obtained by combining the corresponding effect achievement factor and response delay correction coefficient. The combined synergistic impact of each evaluation node is calculated by subtracting the actual combined impact from the corresponding combined baseline impact.

[0057] In this embodiment, to avoid selecting the switching action combination solely based on the rated reactive power compensation capacity of the parallel capacitors, the present invention further compares the actual voltage control effects of different switching action combinations under the same reactive power compensation requirements. Since different parallel capacitors have different installation locations, rated capacities, and corresponding grid connection relationships, even if multiple switching action combinations can meet the same reactive power compensation requirements, their voltage impact on multiple evaluation nodes may differ. Therefore, it is necessary to compare the actual impact of different switching action combinations based on the standard single-action impact amount formed by historical switching actions.

[0058] Specifically, based on the reactive power compensation requirements of each evaluation node, multiple candidate switching action combinations are determined from the parallel capacitors in the target distribution network area that are in an available state; wherein, the reactive power compensation requirements are used to characterize the reactive power compensation capacity required by the current evaluation node to reach the target voltage state, which is determined based on the voltage deviation rate before the aforementioned evaluation node's action, the target voltage, and the node's short-circuit capacity.

[0059] It should be noted that the present invention does not determine the preferred combination based on the number of capacitors included in the candidate switching action combination. Instead, it compares different candidate switching action combinations that meet the same reactive power compensation requirements under the same control requirements. Thus, after excluding the influence of reactive power compensation capacity differences, it can further identify the differences in the combination effects of different capacitor combinations due to differences in installation location, historical action effects, and equipment response characteristics.

[0060] For each candidate switching action combination, the standard single action influence of each parallel capacitor in the candidate switching action combination is superimposed according to the evaluation node to obtain the combined benchmark influence of each evaluation node corresponding to the candidate switching action combination.

[0061] Specifically, for any candidate switching action combination, the standard single-action impact of each parallel capacitor in the candidate switching action combination under the corresponding reactive power compensation requirement is obtained, and corresponding matching is performed according to the evaluation node; for the same evaluation node, the standard single-action impact of each parallel capacitor in the candidate switching action combination corresponding to the evaluation node is superimposed to obtain the combined baseline impact of the candidate switching action combination at the evaluation node; in the same way, all evaluation nodes involved in the candidate switching action combination are calculated to obtain the combined baseline impact of each evaluation node corresponding to the candidate switching action combination.

[0062] The standard single-action impact is determined based on historical operating data when parallel capacitors perform switching actions individually, taking into account the voltage impact, effect achievement factor, and response delay correction coefficient generated by the corresponding switching action. Therefore, the combined benchmark impact is not directly calculated based on the ideal power grid model, but is obtained by superimposing the impact of each standard single-action action formed by actual operating data. It is used to characterize the impact level that the candidate switching action combination should produce at each evaluation node when the single-action impacts of each parallel capacitor can be independently superimposed.

[0063] It should be noted that, due to the different installation locations, rated capacities, and electrical connections between different parallel capacitors and each evaluation node, the standard single-action impact of the same parallel capacitor on different evaluation nodes may also be different. Therefore, when determining the combined baseline impact, the standard single-action impact of each parallel capacitor is not simply added together, but rather superimposed according to the evaluation node, so that the resulting combined baseline impact can reflect the expected differences in the impact of the candidate switching action combination on different evaluation nodes.

[0064] For example, for a candidate switching action combination consisting of a first parallel capacitor and a second parallel capacitor, if the first parallel capacitor and the second parallel capacitor have standard single-action influence quantities corresponding to evaluation nodes A, B, and C, respectively, then the standard single-action influence quantities of the first parallel capacitor and the second parallel capacitor corresponding to evaluation node A are superimposed to obtain the combined baseline influence quantity of the candidate switching action combination at evaluation node A; then the combined baseline influence quantities corresponding to evaluation nodes B and C are determined in the same way.

[0065] Furthermore, for each candidate switching action combination, the voltage influence is determined based on the voltage state characteristics of each candidate switching action combination at each evaluation node, and combined with the corresponding effect achievement factor and response delay correction coefficient, the actual combined influence of each evaluation node is obtained.

[0066] It should be noted that for a candidate switching combination containing multiple parallel capacitors, for each evaluation node, the combined voltage influence of the evaluation node is comprehensively corrected based on the response delay correction coefficient corresponding to each parallel capacitor. Specifically, the influence weight corresponding to each response delay correction coefficient can be determined based on the contribution ratio of each parallel capacitor to the standard single action influence of the evaluation node in the combined baseline influence, and a weighted calculation is performed based on the influence weight to obtain the combined response correction coefficient corresponding to the candidate switching action combination.

[0067] For example, for a candidate switching action combination consisting of a first parallel capacitor and a second parallel capacitor, at evaluation node A, the standard single-action influence of the first parallel capacitor is 0.12, and the standard single-action influence of the second parallel capacitor is 0.08. Therefore, the combined baseline influence of this candidate switching action combination at evaluation node A is 0.20. If the response delay correction coefficients for the first and second parallel capacitors are 0.9 and 0.7, respectively, then based on the proportion of each standard single-action influence to the combined baseline influence, the influence weights for the first and second parallel capacitors are determined to be 0.6 and 0.4, respectively. The response delay correction coefficients are then weighted to obtain a combined response correction coefficient of 0.82 for this candidate switching action combination at evaluation node A.

[0068] Specifically, for any evaluation node, the voltage sampling data within the first time window before the execution of the candidate switching action combination is arranged in chronological order to form pre-action voltage time series data. The voltage change trend of the evaluation node is determined based on the pre-action voltage time series data, and the voltage change trend is extended to the end of the second time window after the completion of the candidate switching action combination to obtain the predicted voltage value of the evaluation node without executing the candidate switching action combination. The measured voltage value of the evaluation node at the end of the second time window is obtained, and the voltage impact of the candidate switching action combination on the evaluation node is obtained based on the difference between the measured voltage value and the predicted voltage value.

[0069] It should be noted that the voltage impact of the candidate switching action combination is determined in the same way as the voltage impact of the aforementioned single switching action. Both are based on the voltage change trend before the action to predict the voltage value under no switching action, and are compared with the measured voltage value after the action is completed. This eliminates the interference of the natural voltage change trend before the switching action is executed on the actual impact of the combination, so that the determined voltage impact can reflect the voltage change generated by the actual execution of the candidate switching action combination.

[0070] Furthermore, based on the comparison results of the post-action voltage deviation rate of each evaluation node after the completion of each candidate switching action combination with the corresponding target voltage deviation rate, the effect achievement factor corresponding to each evaluation node is determined; and based on the comparison results of the actual action response time and the reference action response time corresponding to each parallel capacitor in the candidate switching action combination, the response delay correction coefficient corresponding to each parallel capacitor is determined.

[0071] Furthermore, the voltage impact quantity and effect achievement factor corresponding to each evaluation node are integrated, and the response delay correction coefficient corresponding to each parallel capacitor in the candidate switching action combination is combined to correct the voltage impact quantity of each evaluation node, so as to obtain the actual combined impact quantity corresponding to each evaluation node.

[0072] Furthermore, the combined actual impact of each evaluation node is calculated by comparing it with the corresponding combined baseline impact, thus obtaining the combined synergistic impact of each evaluation node.

[0073] Specifically, for any candidate throwing and cutting action combination, the actual combined impact and the baseline combined impact of the candidate throwing and cutting action combination at each evaluation node are obtained. For the same evaluation node, the difference between the actual combined impact and the baseline combined impact is calculated to obtain the combined synergistic impact of the candidate throwing and cutting action combination at that evaluation node. In the same way, the calculation is performed on all evaluation nodes involved in the candidate throwing and cutting action combination to obtain the combined synergistic impact of each evaluation node corresponding to the candidate throwing and cutting action combination.

[0074] It should be noted that the combined synergistic influence is used to characterize the degree of directional change in the overall voltage influence actually generated by the candidate switching action combination relative to the superposition result of the standard single-action influence of each parallel capacitor. When the combined synergistic influence is greater than or equal to 0, it indicates that the overall voltage influence actually generated by the candidate switching action combination is not lower than the superposition result of the influence when each parallel capacitor is switched individually, and there is no weakening of the overall influence caused by the combined switching. When the combined synergistic influence is less than 0, it indicates that the overall voltage influence actually generated by the candidate switching action combination is lower than the superposition result of the influence when each parallel capacitor is switched individually, indicating that there is a weakening of the combined influence after multiple parallel capacitors are switched at the same time.

[0075] Further, a preferred switching combination is determined based on the combined synergistic influence of each evaluation node corresponding to each candidate switching action combination. Specifically, for any candidate switching action combination, the evaluation node that generates the reactive power compensation requirement is determined as the target evaluation node, and the combined synergistic influence of the candidate switching action combination at the target evaluation node is obtained. When the combined synergistic influence is greater than or equal to 0, it indicates that the actual voltage impact generated by the candidate switching action combination is not less than the sum of the influence of each parallel capacitor individually switching, and the candidate switching action combination is determined as the preferred switching combination. When the combined synergistic influence is less than 0, it indicates that the actual voltage impact generated by the candidate switching action combination is less than the sum of the influence of each parallel capacitor individually switching, and the candidate switching action combination is excluded.

[0076] It should be noted that this invention does not select only a single candidate throwing action combination based on the magnitude of the combined synergistic influence. Instead, it uses whether the combined synergistic influence is less than 0 as the screening criterion for the combined synergistic relationship. Multiple combinations with a combined synergistic influence greater than or equal to 0 are retained from the candidate throwing action combinations to form multiple preferred throwing action combinations. These multiple preferred throwing action combinations are then used as candidate control schemes for subsequent risk assessment.

[0077] Furthermore, for the reactive power compensation requirements of each evaluation node, the individual switching actions and preferred switching combinations that meet the reactive power compensation requirements are taken as candidate control schemes. Based on the comparison results of the standard single action impact or combined actual impact of each candidate control scheme with the preset impact threshold, it is determined whether to generate a risk signal.

[0078] Determining whether to generate a risk signal includes: Compare the standard single-action impact or combined actual impact of each candidate control scheme with the preset impact threshold. If there is a candidate control scheme that reaches the preset impact threshold, no risk signal is generated; If no candidate control scheme reaches the preset impact threshold, a risk signal is generated.

[0079] In this embodiment, by obtaining the standard single-action impact value corresponding to each parallel capacitor and the combined actual impact value corresponding to the preferred switching combination, it is further determined whether there is a candidate control scheme that can generate a voltage impact amplitude that meets the voltage control requirements under the current reactive power compensation demand.

[0080] Specifically, for any evaluation node, the reactive power compensation requirement corresponding to that evaluation node is obtained, and a single switching action that can meet the reactive power compensation requirement is determined from the parallel capacitors that are in an available state, and the preferred switching combination is taken as a candidate control scheme.

[0081] For example, when the reactive power compensation demand corresponding to a certain evaluation node is 5Mvar, if there is a single parallel capacitor with a rated capacity of 5Mvar, then the individual switching action corresponding to the parallel capacitor can be used as a candidate control scheme; if there is no single 5Mvar parallel capacitor, but there are two parallel capacitors with rated capacities of 2Mvar and 3Mvar respectively, then the switching combination formed by the two parallel capacitors can be used as a candidate control scheme.

[0082] Furthermore, for a single switching action, the corresponding standard single-action influence quantity is obtained, and the absolute value of the standard single-action influence quantity is calculated as the single-action influence amplitude corresponding to the single switching action; for a preferred switching combination, the corresponding combined actual influence quantity is obtained, and the absolute value of the combined actual influence quantity is calculated as the combined influence amplitude corresponding to the preferred switching combination; the single-action influence amplitude or combined influence amplitude corresponding to each candidate control scheme is compared with the preset influence quantity threshold.

[0083] It should be noted that the preset impact threshold is used to characterize the minimum voltage control impact amplitude required by the switching control scheme under the current reactive power compensation demand, and its value corresponds to the reactive power compensation demand. The preset impact threshold can be determined based on historical switching action data. Specifically, historical switching actions are classified according to reactive power compensation demand, and the actual impact amount corresponding to the historical switching actions that meet the preset voltage control requirements under each type of reactive power compensation demand is obtained. The absolute value of the actual impact amount is taken to obtain the corresponding historical impact amplitude. From the historical impact amplitude, the range of impact amplitudes that can meet the voltage control requirements is determined, and the lower limit of the impact amplitude range is used as the preset impact threshold for the corresponding reactive power compensation demand. The preset impact threshold can also be modified in conjunction with the actual voltage control requirements of the distribution network to ensure that the threshold is not lower than the minimum impact amplitude corresponding to the current voltage control requirements.

[0084] If there is a candidate control scheme whose single-action influence amplitude or combined influence amplitude is greater than or equal to the preset influence threshold, it indicates that there is at least one switching method that can generate a voltage influence amplitude that meets the expected voltage control requirements under the current reactive power compensation demand, and no risk signal is generated at this time.

[0085] If the single-action influence amplitude and combined influence amplitude of each candidate control scheme are less than the preset influence threshold, it indicates that the currently available individual switching actions and switching combinations cannot produce the required voltage control influence amplitude. The current reactive power compensation requirement lacks an effective switching control scheme, and a risk signal is generated at this time.

[0086] Example 2: This application also provides an electronic device. The electronic device may include one or more processors and one or more memories. The memories store computer-readable code, which, when executed by the one or more processors, can perform a situational awareness-based power grid risk assessment method as described above.

[0087] The method according to the embodiments of this application can also be implemented using the architecture of the electronic device shown in this application. The electronic device may include a bus, one or more CPUs, ROM, RAM, a communication port connected to a network, input / output, a hard disk, etc. The storage device in the electronic device, such as a ROM or hard disk, may store a situational awareness-based power grid risk assessment method provided in this application. Furthermore, the electronic device may also include a user interface. Of course, the architecture shown in this application is merely exemplary; when implementing different devices, one or more components in the electronic device shown in this application may be omitted according to actual needs.

[0088] Example 3: This embodiment of the invention also proposes a computer-readable storage medium storing a situation-aware power grid risk assessment program. When the situation-aware power grid risk assessment program is executed by a processor, it implements the steps of the situation-aware power grid risk assessment method described above.

[0089] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0090] The aforementioned computer-readable storage medium may be included in a situation-aware power grid risk assessment device; or it may exist independently and not be assembled into a situation-aware power grid risk assessment device.

[0091] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a reference structure" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0092] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A power grid risk assessment method based on situational awareness, characterized in that, The method includes: S1: Obtain the operating status data and parallel capacitor switching action records of the target distribution network area, determine the evaluation node corresponding to each switching action, and obtain the voltage operation data of each evaluation node before and after the switching action to determine the voltage state characteristics corresponding to each evaluation node. S2: For each parallel capacitor switching action, determine the response effect of the switching action, and calculate the standard single-action influence of each switching action based on the influence of the switching action on the voltage state characteristics; S3: Determine candidate switching action combinations based on the reactive power compensation requirements of each evaluation node, obtain the combined baseline influence of each candidate switching action combination, calculate the combined actual influence, determine the combined synergistic influence based on the difference between the combined actual influence and the combined baseline influence, and obtain the preferred switching combination. S4: For the reactive power compensation requirements of each evaluation node, the individual switching actions and preferred switching combinations that meet the reactive power compensation requirements are taken as candidate control schemes. Based on the comparison results of the standard single action influence or combined actual influence of each candidate control scheme with the preset influence threshold, it is determined whether to generate a risk signal.

2. The power grid risk assessment method based on situational awareness according to claim 1, characterized in that, Acquire operational status data and parallel capacitor switching records for the target distribution network area, including: Using the installation location of the parallel capacitor corresponding to the switching action as the reference location for determining the influence range, multiple nodes that are electrically related to the installation location and within a preset electrical distance range are determined according to the distribution network topology, and these multiple nodes are used as the evaluation nodes corresponding to the switching action. Obtain the voltage amplitude of each evaluation node within the first time window before the issuance of the switching command for the switching action, and use it as the voltage value before the action; Obtain the voltage amplitude of each evaluation node within the second time window after the completion of the switching action, and use it as the voltage value after the action.

3. The power grid risk assessment method based on situational awareness according to claim 2, characterized in that, Determine the voltage state characteristics corresponding to each evaluation node, including: Obtain the rated voltage value of each evaluation node. For each evaluation node, calculate the voltage deviation rate before action based on the voltage value before action and the rated voltage value; calculate the voltage deviation rate after action based on the voltage value after action and the rated voltage value; calculate the voltage change rate before action based on the voltage value before action and the sampling interval; calculate the voltage change rate after action based on the voltage value after action and the sampling interval. The voltage values ​​before the action, the voltage deviation rate before the action, the voltage change rate before the action, the voltage values ​​after the action, the voltage deviation rate after the action, and the voltage change rate after the action of each evaluation node are integrated to form the voltage state characteristics of each evaluation node corresponding to the switching action.

4. The power grid risk assessment method based on situational awareness according to claim 3, characterized in that, Determine the response of the throwing and cutting motion, including: The time of the issuance of the switching command and the time of completion of the switching action are obtained, and the time interval between the completion time of the switching action and the issuance time of the switching command is determined as the actual action response time of the switching action; Based on the inherent motion characteristics corresponding to the throwing and cutting motion, determine the baseline motion response time of the throwing and cutting motion; The actual action response time is compared with the baseline action response time; If the actual action response time is less than or equal to the baseline action response time, the response is determined to be normal. If the actual action response time is greater than the baseline action response time, the response is determined to be delayed, and a response delay correction coefficient is determined.

5. The power grid risk assessment method based on situational awareness according to claim 4, characterized in that, Based on the impact of switching actions on voltage state characteristics, the standard single-action impact of each switching action is calculated, including: For each evaluation node, the voltage value without switching action is predicted based on the voltage change trend in the first time window before the action. The difference between the measured voltage value and the predicted value in the second time window after the action is used as the voltage influence of the switching action on each voltage state characteristic. Based on the comparison between the voltage deviation rate after the action of each evaluation node and the target voltage deviation rate, the effect achievement factor of the switching action on each evaluation node is determined. The voltage impact of each evaluation node, the effect achievement factor, and the response delay correction coefficient are combined to calculate the single-action impact of the switching action on each voltage state characteristic. Obtain the historical single-action impact value record under the reactive power compensation requirement corresponding to the switching action, add the current single-action impact value to the historical single-action impact value record, calculate the average value of the updated single-action impact value, and use it as the standard single-action impact value of the switching action under the reactive power compensation requirement.

6. The power grid risk assessment method based on situational awareness according to claim 5, characterized in that, Based on the comparison between the voltage deviation rate after the action and the target voltage deviation rate at each evaluation node, the achievement factor of the switching action for each evaluation node is determined, including: Obtain the preset target voltage deviation rate for each evaluation node, and compare the absolute value of the voltage deviation rate after the action of each evaluation node with the target voltage deviation rate. If the absolute value of the voltage deviation rate after the action is less than or equal to the target voltage deviation rate, it is determined that the switching action has the expected effect on the voltage control of each evaluation node, and the effect achievement factor is recorded as 1. If the absolute value of the voltage deviation rate after the action is greater than the target voltage deviation rate, it will be determined that the voltage control effect of the switching action on each evaluation node has not met expectations, and the ratio of the target voltage deviation rate to the absolute value of the voltage deviation rate after the action will be used as the effect achievement factor.

7. The power grid risk assessment method based on situational awareness according to claim 6, characterized in that, The combined synergistic effect is determined based on the difference between the actual combined effect and the combined baseline effect, including: Based on the reactive power compensation requirements of each evaluation node, multiple candidate switching action combinations that meet the same reactive power compensation requirements are determined from the available parallel capacitors. For each candidate switching action combination, the standard single action influence of each parallel capacitor in each candidate switching action combination is superimposed according to the evaluation node to obtain the combined benchmark influence of each evaluation node corresponding to each candidate switching action combination. For each candidate switching action combination, the voltage impact is determined based on the voltage state characteristics of each candidate switching action combination at each evaluation node, and the actual impact of the combination at each evaluation node is obtained by combining the corresponding effect achievement factor and response delay correction coefficient. The combined synergistic impact of each evaluation node is calculated by subtracting the actual combined impact from the corresponding combined baseline impact.

8. The power grid risk assessment method based on situational awareness according to claim 7, characterized in that, Determining whether to generate a risk signal includes: Compare the standard single-action impact or combined actual impact of each candidate control scheme with the preset impact threshold. If there is a candidate control scheme that reaches the preset impact threshold, no risk signal is generated; If no candidate control scheme reaches the preset impact threshold, a risk signal is generated.

9. An electronic device comprising a processor and a memory, wherein, The memory stores computer program instructions, which, when executed by the processor, perform the method as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, It stores a computer program thereon, which, when executed by a processor, implements the method as described in any one of claims 1-8.

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