Power distribution system overreach risk assessment method, device, and medium

Abstract

The application provides a power distribution system over-limit risk assessment method, device and medium, which can be applied to the technical field of power distribution system over-limit risk assessment. The method comprises the following steps: determining the node voltage interval of each node and the line active power interval and line reactive power interval of each line; by analyzing the first positional relationship between the node voltage interval of the node and the voltage safety constraint interval, the over-limit type of the node voltage of the node is determined; by analyzing the second positional relationship between the line power interval of the line and the capacity constraint interval, the overload type of the line power of the line is determined; the over-limit risk index of the node voltage of each node and the line overload risk index of each line are determined by respectively using the over-limit evaluation mode corresponding to the over-limit type and the overload evaluation mode corresponding to the overload type; and the over-limit risk assessment result for the power distribution system is determined according to the over-limit risk index of the node voltage of each node and the line overload risk index of each line.

Description

Technical Field

[0001] This application relates to the field of power distribution system over-limit risk assessment technology, and more specifically to a method, equipment and medium for power distribution system over-limit risk assessment. Background Technology

[0002] The increasing proportion of distributed generation (DG) connections to distribution networks, coupled with their unpredictability and random fluctuations in node net power, leads to significant uncertainty in the network's operational status. This operational uncertainty directly introduces the risk of exceeding safety constraints; voltage overruns and line overloads can affect the power supply quality, equipment lifespan, and operational reliability of the distribution system. To ensure the safe operation of the distribution system, it is necessary to effectively identify and address the risk of exceeding constraints under uncertain conditions.

[0003] However, when conducting over-limit risk assessments of power distribution systems, traditional deterministic constraint verification methods typically rely solely on a single power flow result for safety verification to determine whether the state meets safety constraints. This makes it difficult to reflect the range of state changes under uncertain disturbances and their potential over-limit risks, resulting in low accuracy in over-limit risk assessments. Summary of the Invention

[0004] In view of the above problems, this application provides a method, equipment and medium for assessing the risk of exceeding limits in a power distribution system.

[0005] According to the first aspect of this application, a method for assessing the risk of exceeding limits in a power distribution system is provided, comprising: determining the node voltage range of each node and the line active power range and line reactive power range of each line based on the node voltage time-series data of each node and the line active power time-series data and line reactive power time-series data of each line during the operation of the power distribution system; determining the type of node voltage exceeding limits by analyzing a first positional relationship between the node voltage range and the voltage safety constraint range; and determining the type of line power overload by analyzing a second positional relationship between the line power range and the capacity constraint range, wherein the line power range is determined based on the line active power range and the line reactive power range, and the second positional relationship is determined by: [the method is described in the original text, but the translation is incomplete]. The capacity constraint intervals are mapped to a two-dimensional space. The line power interval is a rectangular area composed of the line active power interval and the line reactive power interval, while the capacity constraint interval is a circular area with the origin as the center and the maximum apparent power constraint value as the radius. Multiple vertices of the line power interval are compared with the circular area in the two-dimensional space to determine the second positional relationship between the line power interval and the capacity constraint interval. Using the over-limit assessment method corresponding to the over-limit type and the overload assessment method corresponding to the overload type, the node voltage over-limit risk index of each node and the line overload risk index of each line are determined. Based on the node voltage over-limit risk index of each node and the line overload risk index of each line, the overall over-limit risk index of the distribution system is determined. Based on the overall over-limit risk index, the over-limit risk assessment result for the distribution system is determined.

[0006] According to an embodiment of this application, analyzing the first positional relationship between a node's voltage range and a voltage safety constraint range includes: mapping the node's voltage range and the voltage safety constraint range to a one-dimensional space; comparing the lower and upper bounds of the node's voltage range and the lower and upper bounds of the voltage safety constraint range in the one-dimensional space to determine the first positional relationship between the node's voltage range and the voltage safety constraint range; if the first positional relationship indicates that the voltage safety constraint range includes the node's voltage range, determining the over-limit type as "not over-limit"; if the first positional relationship indicates that the lower bound of the node's voltage range is less than the lower bound of the voltage safety constraint range, determining the over-limit type as "over-lower bound"; if the first positional relationship indicates that the upper bound of the node's voltage range is greater than the upper bound of the voltage safety constraint range, determining the over-limit type as "over-upper bound".

[0007] According to embodiments of this application, determining the overload type of line power includes: determining the overload type as no overload when all vertices are located inside a circular region; determining the overload type as apparent power overload only when at least one vertex is located outside the circular region and the absolute value of the active power represented by all vertices is less than the radius of the circular region; and determining the overload type as active power-dominated apparent power overload when the absolute value of the active power represented by at least one vertex is greater than or equal to the radius of the circular region.

[0008] According to embodiments of this application, determining the node voltage over-limit risk index for each node includes: when the over-limit type is below the lower limit, determining a first voltage over-limit risk index of the below-limit type based on the lower bound of the node voltage range and the lower bound of the voltage safety constraint range, as the node voltage over-limit risk index; when the over-limit type is above the upper limit, determining a second voltage over-limit risk index of the above-upper limit type based on the upper bound of the node voltage range and the upper bound of the voltage safety constraint range, as the node voltage over-limit risk index; when the over-limit type includes both above and below the upper limit, determining the maximum value of the first and second voltage over-limit risk indices as the node voltage over-limit risk index.

[0009] According to the embodiments of this application, determining the line overload risk index for each line includes: when the overload type is apparent power overload only, determining a first line overload risk index for apparent power overload only based on the maximum distance between each vertex and the origin and the maximum apparent power constraint value, and using it as the line overload risk index; when the overload type is active power-dominated apparent power overload, determining a second line overload risk index for active power-dominated apparent power overload based on the maximum absolute value of the active power represented by multiple vertices and the maximum apparent power constraint value, and using it as the line overload risk index.

[0010] According to an embodiment of this application, the overall over-limit risk index includes a weak over-limit risk index and a weighted over-limit risk index. The overall over-limit risk index of the power distribution system is determined based on the node voltage over-limit risk index of each node and the line overload risk index of each line. This includes: determining the overall weak over-limit risk index of the power distribution system based on the maximum value of the node voltage over-limit risk index and the node number corresponding to the maximum value of the node voltage over-limit risk index, and the maximum value of the line overload risk index and the line number corresponding to the maximum value of the line overload risk index; and weighting and fusing the node voltage over-limit risk index of each node and the line overload risk index of each line to determine the overall weighted over-limit risk index of the power distribution system.

[0011] According to an embodiment of this application, the overall over-limit risk index of the power distribution system includes a weighted over-limit risk index, which is obtained by weighting and fusing the node voltage over-limit risk index of each node and the line overload risk index of each line. Based on the overall over-limit risk index, the over-limit risk assessment result for the power distribution system is determined, including: if the weighted over-limit risk index is higher than a preset risk threshold, the over-limit risk assessment result indicates that the power distribution system is over-limit; if the weighted over-limit risk index is not higher than the preset risk threshold and is greater than zero, the over-limit risk assessment result indicates that the power distribution system has over-limit risk, and weak over-limit risk indicators are identified; if the weighted over-limit risk index is zero, the over-limit risk assessment result indicates that the power distribution system is not over-limit.

[0012] According to an embodiment of this application, based on the node voltage time-series data of each node and the line active power time-series data and line reactive power time-series data of each line during the operation of the power distribution system, the node voltage range of each node and the line active power range and line reactive power range of each line are determined respectively, including: for each node, the minimum and maximum values ​​of the node time-series data are used as the lower and upper bounds of the node voltage range, respectively, to obtain the node voltage range of the node; for each line, the minimum and maximum values ​​of the line active power time-series data are used as the lower and upper bounds of the line active power range, respectively, and the minimum and maximum values ​​of the line reactive power time-series data are used as the upper and lower bounds of the line reactive power range, respectively, to obtain the line active power range and line reactive power range of the line.

[0013] The second aspect of this application provides a power distribution system over-limit risk assessment device, comprising: an interval determination module, used to determine the node voltage interval of each node and the line active power interval and line reactive power interval of each line based on the node voltage time-series data of each node and the line active power time-series data and the line reactive power time-series data of each line during the operation of the power distribution system; an over-limit determination module, used to determine the over-limit type of the node voltage by analyzing the first positional relationship between the node voltage interval and the voltage safety constraint interval; and an overload determination module, used to determine the over-limit type of the line voltage by analyzing the second positional relationship between the line power interval and the capacity constraint interval. The system analyzes the relationship between the parameters to determine the overload type of the line power. The line power range is determined based on the line's active power range and reactive power range. The risk assessment module is used to determine the node voltage overload risk index of each node and the line overload risk index of each line using the overload assessment methods corresponding to the overload type and the overload assessment methods corresponding to the overload type, respectively. The index determination module is used to determine the overall overload risk index of the distribution system based on the node voltage overload risk index of each node and the line overload risk index of each line. The result determination module is used to determine the overload risk assessment result for the distribution system based on the overall overload risk index.

[0014] A third aspect of this application provides an electronic device comprising: one or more processors; and a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the method described above.

[0015] A fourth aspect of this application also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the above-described method.

[0016] The fifth aspect of this application also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the above-described method.

[0017] According to embodiments of this application, the over-limit type is determined by analyzing the first positional relationship between the node voltage range and the voltage safety constraint range, and the overload type is determined by analyzing the second positional relationship between the line power range determined by the active and reactive power ranges and the capacity constraint range. Then, for different over-limit and overload types, corresponding evaluation methods are used to calculate the node voltage over-limit risk index and the line overload risk index, and the overall over-limit risk index of the distribution system is obtained by combining them. This solves the technical problems in the prior art of being unable to systematically evaluate the over-limit risk of the distribution system under uncertain disturbances and being unable to distinguish over-limit / overload types to provide targeted risk quantification basis. It can quantify and evaluate the overall over-limit risk of the system, distinguish the specific types of voltage over-limit and line overload, and improve the evaluation accuracy. Attached Figure Description

[0018] The above-mentioned contents, other objects, features and advantages of this application will become clearer from the following description of embodiments of this application with reference to the accompanying drawings.

[0019] Figure 1 The diagram illustrates an application scenario of the power distribution system over-limit risk assessment method, equipment, and medium according to embodiments of this application.

[0020] Figure 2 A flowchart of a method for assessing the risk of exceeding limits in a power distribution system according to an embodiment of this application is shown.

[0021] Figure 3 The diagram illustrates how the risk classification and early warning results change over time according to a specific embodiment of this application.

[0022] Figure 4 The diagram illustrates how the over-limit risk index of a typical node voltage changes over time according to a specific embodiment of this application.

[0023] Figure 5The overload risk index of a typical line power according to an embodiment of this application is shown to change over time.

[0024] Figure 6 The geometric relationship between the node voltage range and safety constraints according to a specific embodiment of this application is shown.

[0025] Figure 7 The geometric relationship between line power range and capacity constraints according to a specific embodiment of this application is shown.

[0026] Figure 8 The expected control effect of a weak state under the action of a strategy according to a specific embodiment of this application is shown.

[0027] Figure 9 This demonstrates the expected regulatory effect on the overall network status under the action of a strategy according to a specific embodiment of this application.

[0028] Figure 10 A structural block diagram of a power distribution system over-limit risk assessment device according to an embodiment of this application is shown.

[0029] Figure 11 A block diagram of an electronic device suitable for implementing a method for assessing the risk of exceeding limits in a power distribution system, according to an embodiment of this application, is shown. Detailed Implementation

[0030] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0032] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0033] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0034] Based on the characterization of operating state ranges, power distribution systems must meet safety constraints such as node voltage and line capacity. Since the state fluctuates within a certain range, its safety is no longer manifested as a single point of operation exceeding limits, but rather as the relationship between the state range and the safety boundary. Especially in uncertain scenarios with multiple nodes and multiple lines coupled, how to assess the overall risk level of the system, identify sources of limit-exceeding risks, and formulate control strategies in advance are crucial issues for ensuring the safe operation of power distribution systems with a high proportion of distributed power sources.

[0035] Traditional deterministic constraint verification methods typically rely solely on a single power flow result for safety verification, determining whether the state meets safety constraints. This fails to reflect the range of state changes and potential exceedance risks under uncertain perturbations. Furthermore, the lack of a unified control approach that differentiates exceedance types makes it difficult to provide targeted support for risk prevention and control. Existing research largely focuses on risk quantification and control within probabilistic or optimization frameworks. However, under uncertainty interval representations, a clear geometric relationship exists between the operating state and safety constraints, and research on exceedance risks based on this interval geometry is relatively insufficient.

[0036] Therefore, based on the geometric relationships within the intervals, the systematic connection between risk management aspects such as quantitative assessment of over-limit risks, source identification, and control strategies can be further clarified. In multi-constraint over-limit scenarios considering voltage over-limits and line overloads, how to comprehensively assess system over-limit risks and further analyze the impact of over-limit types and severity on strategy selection still requires in-depth research to provide targeted support for the safe operation of high-proportion photovoltaic power distribution systems.

[0037] Therefore, embodiments of this application provide a method for assessing the risk of exceeding limits in a power distribution system, comprising: determining the node voltage range of each node and the line active power range and line reactive power range of each line based on the node voltage time-series data of each node and the line active power time-series data and the line reactive power time-series data of each line during the operation of the power distribution system; determining the node voltage exceeding limit type of the node by analyzing the first positional relationship between the node voltage range and the voltage safety constraint range; determining the line power overload type of the line by analyzing the second positional relationship between the line power range and the capacity constraint range, wherein the line power range is determined based on the line active power range and the line reactive power range of the line; determining the node voltage exceeding limit risk index of each node and the line overload risk index of each line by using the exceeding limit assessment method corresponding to the exceeding limit type and the overload assessment method corresponding to the overload type, respectively; determining the overall exceeding limit risk index of the power distribution system based on the node voltage exceeding limit risk index of each node and the line overload risk index of each line; and determining the exceeding limit risk assessment result for the power distribution system based on the overall exceeding limit risk index.

[0038] The embodiments of this application determine the over-limit type by analyzing the first positional relationship between the node voltage range and the voltage safety constraint range, and determine the overload type by analyzing the second positional relationship between the line power range determined by the active and reactive power ranges and the capacity constraint range. Then, for different over-limit and overload types, corresponding evaluation methods are used to calculate the node voltage over-limit risk index and the line overload risk index, and the overall over-limit risk index of the distribution system is obtained by combining them. This solves the technical problems in the prior art of being unable to systematically evaluate the over-limit risk of the distribution system under uncertain disturbances and being unable to distinguish over-limit / overload types to provide targeted risk quantification basis. It can quantify and evaluate the overall over-limit risk of the system, distinguish the specific types of voltage over-limit and line overload, and improve the evaluation accuracy.

[0039] Figure 1 The diagram illustrates an application scenario of the power distribution system over-limit risk assessment method, equipment, and medium according to embodiments of this application.

[0040] like Figure 1 As shown, the application scenario according to this embodiment may include a first terminal device 101, a second terminal device 102, a third terminal device 103, a network 104, and a server 105. The network 104 serves as a medium for providing a communication link between the first terminal device 101, the second terminal device 102, the third terminal device 103, and the server 105. The network 104 may include various connection types, such as wired or wireless communication links, or fiber optic cables, etc.

[0041] Users can use the first terminal device 101, the second terminal device 102, and the third terminal device 103 to interact with the server 105 via the network 104 to receive or send messages, etc. Various communication client applications can be installed on the first terminal device 101, the second terminal device 102, and the third terminal device 103, such as shopping applications, web browser applications, search applications, instant messaging tools, email clients, social media platform software, etc. (for example only).

[0042] The first terminal device 101, the second terminal device 102, and the third terminal device 103 can be various electronic devices with displays and support web browsing, including but not limited to smartphones, tablets, laptops, and desktop computers.

[0043] Server 105 can be a server that provides various services, such as a backend management server that supports websites browsed by users using the first terminal device 101, the second terminal device 102, and the third terminal device 103 (this is just an example). The backend management server can analyze and process data such as received user requests, and feed back the processing results (such as web pages, information, or data obtained or generated according to user requests) to the terminal devices.

[0044] It should be noted that the power distribution system over-limit risk assessment method provided in this application embodiment can generally be executed by server 105. Correspondingly, the power distribution system over-limit risk assessment device provided in this application embodiment can generally be installed in server 105. The power distribution system over-limit risk assessment method provided in this application embodiment can also be executed by a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105. Correspondingly, the power distribution system over-limit risk assessment device provided in this application embodiment can also be installed in a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105.

[0045] It should be understood that Figure 1 The number of first terminal devices, second terminal devices, third terminal devices, networks, and servers shown in the diagram is merely illustrative. Depending on implementation needs, any number of first terminal devices, second terminal devices, third terminal devices, networks, and servers can be included.

[0046] The following will be based on Figure 1 The described scene, through Figures 2-9 The method for assessing the risk of exceeding limits in the power distribution system according to the embodiments of the application is described in detail.

[0047] Figure 2A flowchart of a method for assessing the risk of exceeding limits in a power distribution system according to an embodiment of this application is shown.

[0048] like Figure 2 As shown, the power distribution system over-limit risk assessment in this embodiment includes operations S210 to S260.

[0049] In operation S210, based on the node voltage time sequence data of each node and the line active power time sequence data and line reactive power time sequence data of each line during the operation of the power distribution system, the node voltage range of each node and the line active power range and line reactive power range of each line are determined respectively.

[0050] In operation S220, the type of over-limit of the node voltage is determined by analyzing the first positional relationship between the node voltage range and the voltage safety constraint range.

[0051] In operation S230, the overload type of the line power is determined by analyzing the second positional relationship between the line power range and the capacity constraint range. The line power range is determined based on the line active power range and the line reactive power range.

[0052] In operation S240, the over-limit assessment method corresponding to the over-limit type and the overload assessment method corresponding to the overload type are used respectively to determine the node voltage over-limit risk index of each node and the line overload risk index of each line.

[0053] When operating S250, the overall over-limit risk index of the power distribution system is determined based on the node voltage over-limit risk index of each node and the line overload risk index of each line.

[0054] When operating S260, the over-limit risk assessment results for the power distribution system are determined based on the overall over-limit risk index.

[0055] In the embodiments of this application, in order to improve the accuracy of the assessment, the risk assessment of the power distribution system exceeding the limit is carried out based on the state interval. The interval expression of the power distribution system state is fully utilized, the positional relationship between the state interval and the safety constraints is analyzed, and the risk exceeding the limit index system is constructed. This system can reflect the range of state changes and potential risk exceeding the limit under uncertain disturbances, and achieve accurate assessment of the risk exceeding the limit of the power distribution system.

[0056] Before conducting an over-limit risk assessment, the node voltage time-series data of each node, as well as the line active power time-series data and line reactive power time-series data of each line can be obtained during the operation of the power distribution system in a preset time period. These data can be used as the state data of the power distribution system to determine the state range of the power distribution system, including the node voltage range, the line active power range, and the line reactive power range.

[0057] For example, the voltage data in the node voltage time series data can be arranged, and the minimum and maximum values ​​can be taken as the lower limit and upper limit of the voltage range of that node, respectively. Similarly, the active power range and reactive power range of each line can be determined based on the active power time series data and reactive power time series data of the line, thereby completing the determination of the state range.

[0058] For example, after arranging the voltage data in the node voltage time series data, the maximum and minimum values ​​of the middle data, which account for 80% of the total data, can be taken as the upper and lower limits, respectively, to avoid interference from a few extreme abnormal data on the range.

[0059] After determining the state ranges of each node and line, further analysis of the positional relationships is conducted to determine the type of over-limit and overload. For node voltage, when the node voltage range is entirely within the voltage safety constraint range, the over-limit type is "no over-limit"; when the node voltage range exceeds the boundary of the voltage safety constraint range, the over-limit type is "over-limit". Furthermore, based on the specific over-limit situation, it can be further determined whether the over-limit exceeds the upper or lower limit.

[0060] For line power, the line power range can be determined based on the line's active power range and reactive power range. The overload type can then be determined by comparing this line power range with the line's capacity constraint range. When the line power range is entirely within the capacity constraint range, the overload type is "no overload"; when the line power range exceeds the capacity constraint range boundary, the overload type is "overload". Furthermore, based on the specific boundary crossing situation, the overload can be further determined as either apparent power overload only or apparent power overload dominated by active power.

[0061] After determining the types of overruns and overloads, risk indicators can be calculated using corresponding assessment methods based on different types of overruns and overloads. For cases where the overrun type is "no overrun" and the overload type is "no overload," the corresponding risk indicator is directly set to 0. For different types of overruns / overloads, the corresponding risk indicator is calculated based on the degree of overrun.

[0062] The overall out-of-bounds risk index can be determined by weighted summation of the node voltage out-of-bounds risk index of all nodes and the line overload risk index of all lines. Based on the magnitude of the overall out-of-bounds risk index, risk levels can be classified, resulting in the final out-of-bounds risk assessment. For example, the larger the overall out-of-bounds risk index, the higher the corresponding risk level.

[0063] According to embodiments of this application, the over-limit type is determined by analyzing the first positional relationship between the node voltage range and the voltage safety constraint range, and the overload type is determined by analyzing the second positional relationship between the line power range determined by the active and reactive power ranges and the capacity constraint range. Then, for different over-limit and overload types, corresponding evaluation methods are used to calculate the node voltage over-limit risk index and the line overload risk index, and the overall over-limit risk index of the distribution system is obtained by combining them. This solves the technical problems in the prior art of being unable to systematically evaluate the over-limit risk of the distribution system under uncertain disturbances and being unable to distinguish over-limit / overload types to provide targeted risk quantification basis. It can quantify and evaluate the overall over-limit risk of the system, distinguish the specific types of voltage over-limit and line overload, and improve the evaluation accuracy.

[0064] According to an embodiment of this application, based on the node voltage time-series data of each node and the line active power time-series data and line reactive power time-series data of each line during the operation of the power distribution system, the node voltage range of each node and the line active power range and line reactive power range of each line are determined respectively, including: for each node, the minimum and maximum values ​​of the node time-series data are used as the lower and upper bounds of the node voltage range, respectively, to obtain the node voltage range of the node; for each line, the minimum and maximum values ​​of the line active power time-series data are used as the lower and upper bounds of the line active power range, respectively, and the minimum and maximum values ​​of the line reactive power time-series data are used as the upper and lower bounds of the line reactive power range, respectively, to obtain the line active power range and line reactive power range of the line.

[0065] In the embodiments of this application, the node time series data can be arranged according to the numerical value, and the maximum and minimum values ​​in all data can be extracted and used as the upper and lower boundaries of the node voltage range to obtain the corresponding node voltage range. Similarly, the line active power range and line reactive power range can be obtained, which will not be elaborated here.

[0066] According to embodiments of this application, by determining the node voltage range, the line active power range, and the line reactive power range, the range of state changes under uncertain disturbances can be represented in the form of ranges, thereby improving the evaluation accuracy.

[0067] According to an embodiment of this application, analyzing the first positional relationship between a node's voltage range and a voltage safety constraint range includes: mapping the node's voltage range and the voltage safety constraint range to a one-dimensional space; comparing the lower and upper bounds of the node's voltage range and the lower and upper bounds of the voltage safety constraint range in the one-dimensional space to determine the first positional relationship between the node's voltage range and the voltage safety constraint range; if the first positional relationship indicates that the voltage safety constraint range includes the node's voltage range, determining the over-limit type as "not over-limit"; if the first positional relationship indicates that the lower bound of the node's voltage range is less than the lower bound of the voltage safety constraint range, determining the over-limit type as "over-lower bound"; if the first positional relationship indicates that the upper bound of the node's voltage range is greater than the upper bound of the voltage safety constraint range, determining the over-limit type as "over-upper bound".

[0068] After mapping the node voltage range and the voltage safety constraint range to a one-dimensional space, the one-dimensional geometric relationship between the node voltage range and the voltage safety constraint range can be used as the first positional relationship.

[0069] The one-dimensional geometric relationship between the node voltage range and the safety constraints is shown in equations (1) to (7) below:

[0070] (1);

[0071] (2);

[0072] (3);

[0073] (4);

[0074] (5);

[0075] (6);

[0076] (7);

[0077] in, , and These represent the sets of one-dimensional geometric relationships for cases where the node voltage interval width is less than the voltage safety constraint interval width, the node voltage interval width is greater than the voltage safety constraint interval width, and all other cases. Indicates node voltage. and These represent the interval variables for the node voltage range and the voltage safety constraint range, respectively. Indicates the width of the interval variable. and These represent the upper and lower bounds of the node voltage range, respectively. and These represent the upper and lower limits of the voltage safety constraint range, respectively.

[0078] After determining the first positional relationship, the over-limit type of the node voltage can be further determined. When the relationship between the node voltage range and the voltage safety constraint range is as shown in Equation (8), the over-limit type is not over-limit:

[0079] (8).

[0080] When the relationship between the node voltage range and the voltage safety constraint range is as shown in equation (9), the over-limit type is the under-limit over-limit:

[0081] (9).

[0082] When the relationship between the node voltage range and the voltage safety constraint range is as shown in Equation (10), the over-limit type is over-limit:

[0083] (10).

[0084] According to the embodiments of this application, by analyzing the first positional relationship between the node voltage range and the voltage safety constraint range, and based on this, the over-limit type is determined, thereby improving the accuracy of the over-limit type and further improving the accuracy of the overall risk assessment.

[0085] According to an embodiment of this application, the overload type of the line power is determined by analyzing the second positional relationship between the line power range and the capacity constraint range, including: mapping the line power range and the capacity constraint range to a two-dimensional space, where the line power range is a rectangular area composed of the line active power range and the line reactive power range, and the capacity constraint range is a circular area with the origin as the center and the maximum apparent power constraint value as the radius; comparing multiple vertices of the line power range with the circular area in the two-dimensional space to determine the second positional relationship between the line power range and the capacity constraint range; determining that the overload type is no overload when all vertices are located inside the circular area; determining that the overload type is only apparent power overload when at least one vertex is located outside the circular area and the absolute value of the active power represented by all vertices is less than the radius of the circular area; and determining that the overload type is active power-dominated apparent power overload when the absolute value of the active power represented by at least one vertex is greater than or equal to the radius of the circular area.

[0086] After mapping the line power range and capacity constraint range to a two-dimensional space, the two-dimensional geometric relationship between the line power range and the capacity constraint range can be used as the second positional relationship.

[0087] The two-dimensional interval geometric relationship between the line power range and the capacity constraint is as follows: (11)~(17):

[0088] (11);

[0089] (12);

[0090] (13);

[0091] (14);

[0092] (15);

[0093] (16);

[0094] (17);

[0095] in, , and Let represent the two-dimensional interval geometric relationships for apparent power not overload, apparent power overload, and all other cases, respectively. and These represent the active power and reactive power of the line, respectively. Represents the set of rectangles formed by the power range of the lines. This represents a circular set constrained by capacity constraints. Indicates the maximum apparent power that the line is allowed to carry. Indicates the apparent power of the line. and These represent the upper and lower bounds of the active power range of the line, respectively. and These represent the upper and lower bounds of the reactive power range of the line, respectively. It represents a two-dimensional real number space and is used to describe points on a plane.

[0096] After determining the second positional relationship, the overload type can be further determined. When the relationship between the line power range and the capacity constraint range is as shown in equations (18) to (20), the overload type is no overload:

[0097] (18);

[0098] (19);

[0099] (20);

[0100] in, Represents a set of rectangles The distance between the vertex and the origin, Indicates the vertex index. Indicates the first The first vertex.

[0101] When the relationship between the line power range and the capacity constraint range is as shown in equations (21) to (22), the overload type is apparent power overload only:

[0102] (twenty one);

[0103] (twenty two);

[0104] in, Indicates the first The active power of the line at the first vertex.

[0105] When the relationship between the line power range and the capacity constraint range is as shown in Equation (23), the overload type is active power-dominated apparent power overload:

[0106] (twenty three).

[0107] According to embodiments of this application, by analyzing the second positional relationship between the line power range and the capacity constraint range, and based on this, the overload type is determined, thereby improving the accuracy of the overload type and further enhancing the accuracy of the overall risk assessment.

[0108] According to embodiments of this application, determining the node voltage over-limit risk index for each node includes: when the over-limit type is below the lower limit, determining a first voltage over-limit risk index of the below-limit type based on the lower bound of the node voltage range and the lower bound of the voltage safety constraint range, as the node voltage over-limit risk index; when the over-limit type is above the upper limit, determining a second voltage over-limit risk index of the above-upper limit type based on the upper bound of the node voltage range and the upper bound of the voltage safety constraint range, as the node voltage over-limit risk index; when the over-limit type includes both above and below the upper limit, determining the maximum value of the first and second voltage over-limit risk indices as the node voltage over-limit risk index.

[0109] The specific calculation method for the node voltage over-limit risk index is shown in equations (24) to (27) below:

[0110] (twenty four);

[0111] (25);

[0112] (26);

[0113] (27);

[0114] in, and Representing nodes respectively Risk indicators for voltage levels falling below the lower limit, above the upper limit, or simultaneously exceeding both the upper and lower limits. and Representing nodes respectively Upper and lower limits of voltage safety constraints. This is the rated value of the node voltage. and Representing nodes respectively Upper and lower bounds of the voltage range, This represents the positive part function, used to determine the node voltage over-limit risk index value to be 0 when the over-limit type of the node voltage is no over-limit.

[0115] According to the embodiments of this application, the corresponding voltage over-limit risk index is calculated separately for different over-limit types, which can intuitively quantify the degree of node voltage over-limit risk, avoid the evaluation bias caused by using a uniform index for different over-limit situations, and further ensure the reliability of risk assessment results.

[0116] According to the embodiments of this application, determining the line overload risk index for each line includes: when the overload type is apparent power overload only, determining a first line overload risk index for apparent power overload only based on the maximum distance between each vertex and the origin and the maximum apparent power constraint value, and using it as the line overload risk index; when the overload type is active power-dominated apparent power overload, determining a second line overload risk index for active power-dominated apparent power overload based on the maximum absolute value of the active power represented by multiple vertices and the maximum apparent power constraint value, and using it as the line overload risk index.

[0117] The specific calculation method for the line overload risk index is shown in the following formulas (28) to (30):

[0118] (28);

[0119] (29);

[0120] (30);

[0121] in, , and These represent the risk indicators for apparent power overload, active power-dominated apparent power overload, and overall overload, respectively. It represents the risk increment coefficient of apparent power overload dominated by active power.

[0122] According to the embodiments of this application, the corresponding line overload risk index is calculated separately for different overload types, which can intuitively quantify the degree of line overload risk, avoid the evaluation bias caused by using a uniform index for different overload conditions, and further ensure the reliability of the risk assessment results.

[0123] According to an embodiment of this application, the overall over-limit risk index includes a weak over-limit risk index and a weighted over-limit risk index. The overall over-limit risk index of the power distribution system is determined based on the node voltage over-limit risk index of each node and the line overload risk index of each line. This includes: determining the overall weak over-limit risk index of the power distribution system based on the maximum value of the node voltage over-limit risk index and the node number corresponding to the maximum value of the node voltage over-limit risk index, and the maximum value of the line overload risk index and the line number corresponding to the maximum value of the line overload risk index; and weighting and fusing the node voltage over-limit risk index of each node and the line overload risk index of each line to determine the overall weighted over-limit risk index of the power distribution system.

[0124] The vulnerability over-limit risk indicator is shown in equation (31) below:

[0125] (31);

[0126] in, This represents a matrix-form indicator of weak over-limit risk. and These represent the maximum value of the node voltage over-limit risk index and the corresponding node number, respectively. and These represent the maximum value of the line overload risk index and the corresponding line number, respectively. and These represent the set of node numbers and the set of line numbers, respectively.

[0127] The specific calculation method for the weighted over-limit risk index is shown in equations (32) to (34) below:

[0128] (32);

[0129] (33);

[0130] (34);

[0131] in, This indicates a weighted over-limit risk indicator. and Representing nodes respectively Voltage over-limit weight and line The power overload weight, Indicates in set The Middle Each weight.

[0132] According to the embodiments of this application, by determining the weighted over-limit risk index and the weak over-limit risk index, the over-limit risk level of the power distribution system can be comprehensively characterized from two dimensions: the overall system risk level and the key weak links. This not only allows us to grasp the overall risk status of the power distribution system, but also allows us to quickly locate the equipment links with the most serious risks, providing a clear direction for the guidance of subsequent control strategies.

[0133] According to an embodiment of this application, the overall over-limit risk index of the power distribution system includes a weighted over-limit risk index, which is obtained by weighting and fusing the node voltage over-limit risk index of each node and the line overload risk index of each line. Based on the overall over-limit risk index, the over-limit risk assessment result for the power distribution system is determined, including: if the weighted over-limit risk index is higher than a preset risk threshold, the over-limit risk assessment result indicates that the power distribution system is over-limit; if the weighted over-limit risk index is not higher than the preset risk threshold and is greater than zero, the over-limit risk assessment result indicates that the power distribution system has over-limit risk, and weak over-limit risk indicators are identified; if the weighted over-limit risk index is zero, the over-limit risk assessment result indicates that the power distribution system is not over-limit.

[0134] In the embodiments of this application, the specific process for graded early warning of power distribution system over-limit risks is as follows:

[0135] when If the power distribution system is confirmed to be within limits, all state intervals are completely within safety constraints, and the conservatism of the interval boundaries provides a certain safety margin, then no control strategy is adopted, and state fluctuations are continuously observed.

[0136] when During this stage, some state ranges may be about to or slightly exceed the constraint boundaries, indicating a potential risk of exceeding limits in the power distribution system, thus triggering a risk warning. At this point, attention begins to focus on weak limit-exceeding risk indicators. This involves identifying vulnerable points and analyzing their fluctuations, preparing adjustment resources in advance, and providing guidance for subsequent regulatory strategies. This is a preset risk threshold.

[0137] when If the distribution system is found to be exceeding limits, and the degree of exceeding the limits of node voltage or line power ranges further increases, the safety margin provided by range conservatism is insufficient, indicating an increased risk of system exceeding limits. At this point, control strategies can be implemented based on pre-prepared control resources, and the expected effect can be assessed to return the system to safety constraints.

[0138] In some embodiments, the obtained system risk warning level and mapping relationship between state and node net power can be used to classify control strategies, analyze the types and degrees of exceeding limits of the state, guide the selection of control strategies, obtain the expected effect under the action of the strategy, and output the guidance scheme of the control strategy.

[0139] Specifically, based on their different effects, regulatory strategies can be categorized into two types: interval contraction strategies and interval shifting strategies.

[0140] Interval contraction strategies: Addressing the risk of excessively wide intervals due to high uncertainty, interval contraction strategies reduce the width of the state interval. This includes both overall contraction to suppress fluctuations and targeted reduction of the upper boundary of the interval. Based on different mechanisms, these can be further divided into two strategies: the first is uncertainty mitigation strategies, which suppress the overall fluctuation range of node net power through energy storage charging and discharging, demand response, etc.; the second is interval capping strategies, which directly reduce one boundary of the interval through methods such as photovoltaic power curtailment. For line power, in the typical high-penetration distributed photovoltaic scenario of interest, the line overload risk mainly manifests as active power-dominated apparent power overload. Therefore, the focus is on reducing one side of the line's active power interval. Compared to the line's active power, the line's reactive power interval is very narrow, therefore, it is not designed to have sufficient reduction capacity.

[0141] Interval shifting strategies: Addressing the risk of operating point deviation due to excessive active power output from distributed generation, interval shifting strategies move the entire state interval to a safe area while maintaining a relatively constant interval width. Typical methods include capacitor bank switching and on-load tap-changing transformer regulation. Interval shifting strategies are suitable for situations where the state interval width does not exceed the acceptable range of safety constraints and the system has sufficient adjustment margin. In reality, in one dimension, due to different operating points, the upper and lower boundary shifts are not entirely equal; in two dimensions, due to the coupling effect of active and reactive power, adjustments in one dimension will affect the state interval boundary in another dimension. To facilitate subsequent strategy guidance analysis, this paper makes the following approximations within a certain operating range: for one-dimensional voltage intervals, the slight differences in the upper and lower boundary shifts are ignored; for two-dimensional line power intervals, the weak coupling effect of single-dimensional regulation on the boundary of another dimension is ignored.

[0142] Based on the two strategies mentioned above, appropriate control strategies can be selected in advance according to the type of state exceedance. When the risk of weak state exceedance originates from a large voltage range or active power-dominated apparent power overload, range contraction strategies are preferred to suppress state uncertainty fluctuations; when the risk of weak state exceedance originates from voltage range shift, range translation strategies are preferred. Furthermore, considering the two-dimensional geometric relationship between the line power range and capacity constraints, suitable power regulation methods can be selected according to the type of line power exceedance. For the problem of line apparent power overload, adjusting reactive power alone can translate the rectangular area downward along the axis into the capacity constraint. However, for line active power-dominated apparent power overload, reactive power regulation methods have weak ability to regulate line active power, and adjusting reactive power alone cannot solve this type of line overload problem; active power regulation methods must be used to translate or contract the rectangular area along the axis, returning it to the circular area of ​​the capacity constraint. It should be noted that this method does not construct an optimization model for specific control variables, but only guides the control strategy for early intervention from a safety perspective by quantitatively assessing the exceedance risk of the state range in the future period.

[0143] In one specific embodiment, based on the above-mentioned method for assessing the risk of exceeding limits in a power distribution system based on state intervals, an uncertain operating scenario with high photovoltaic penetration is constructed to verify the effectiveness of the proposed method in risk classification and early warning, state interval geometric relationships, and control strategy guidance.

[0144] The computer hardware environment for performing the optimized calculations was an Intel(R) Core(TM) i7-12700 with a clock speed of 2.10GHz and 16GB of memory; the software environment was a Windows 11 operating system.

[0145] Figure 3 The diagram illustrates how the risk classification and early warning results change over time according to a specific embodiment of this application.

[0146] like Figure 3 As shown, each dot represents the risk classification and early warning result of the power distribution system exceeding the limit for each time period.

[0147] Figure 4 The diagram illustrates how the over-limit risk index of a typical node voltage changes over time according to a specific embodiment of this application.

[0148] like Figure 4 As shown, each rectangle represents the risk indicator of exceeding limits within each time period.

[0149] Figure 5 The overload risk index of a typical line power according to an embodiment of this application is shown to change over time.

[0150] like Figure 5As shown, each rectangle represents an overload risk indicator for each time period.

[0151] like Figure 3 , Figure 4 and Figure 5 As shown, during the period from 10:00 to 13:50, the risks of node voltage exceeding limits and line overload intensify simultaneously, resulting in a risk of the power distribution system exceeding limits. During the periods from 6:15 to 7:45 and from 15:45 to 17:00, both the line power and voltage ranges operate within safe limits with a certain safety margin, and the power distribution system faces no risk of exceeding limits. At other times, some states operate safely, while others exhibit slight exceedances, placing the power distribution system in a risk warning phase. Therefore, this method effectively identifies system exceedance risks during time-series changes.

[0152] Figure 6 The geometric relationship between the node voltage range and safety constraints according to a specific embodiment of this application is shown.

[0153] like Figure 6 As shown, Figure 6 610 in the figure shows the one-dimensional geometric relationship when the node voltage exceeds the lower limit. Figure 6 620 in the figure shows a one-dimensional geometric relation without exceeding the limit. Figure 6 Figure 630 illustrates the one-dimensional geometric relationship under the condition of exceeding the upper limit. The gray area represents the safety constraint range, and the red area represents the node voltage state range. Therefore, the relative positional relationship between the node voltage range and the safety constraint corresponds to the three types of voltage limit exceeding mathematical models summarized, indicating that the one-dimensional geometric relationship model of this method has good interpretability for the types of node voltage limit exceeding.

[0154] Figure 7 The geometric relationship between line power range and capacity constraints according to a specific embodiment of this application is shown.

[0155] like Figure 7 As shown, Figure 7 710 in the figure shows the two-dimensional geometric relationship under no-load conditions. Figure 7 720 in the figure shows the two-dimensional geometric relationship only under the power overload condition. Figure 7 Figure 730 illustrates the two-dimensional set relationship under active power-dominated apparent power overload conditions. As the net active power at the nodes fluctuates, the active power of the lines changes significantly, while the reactive power of the lines does not change significantly under coupling effects. Figure 7 The results shown are consistent with the mathematical model of the two-dimensional geometric relationship summarized, verifying that the geometric determination model of line power interval can effectively distinguish these three types of cases.

[0156] against Figure 6 The voltage above the upper limit shown in 630 is... Figure 7In scenarios where the line shown in section 730 experiences active power-dominated overload, interval clipping or contraction strategies should be prioritized. Here, a photovoltaic (PV) power curtailment strategy is chosen, limiting the PV output at each node to 800kW. The expected control effect of this strategy on the state interval is analyzed, such as... Figure 8 and Figure 9 As shown.

[0157] Figure 8 The expected control effect of a weak state under the action of a strategy according to a specific embodiment of this application is shown.

[0158] Figure 8 Tables 810 and 820 respectively illustrate the one-dimensional geometric relationship between the voltage range and safety constraints of weak nodes and the two-dimensional geometric relationship between the power range and capacity constraints of weak lines before and after the regulation strategy. Before regulation, the upper bound of the node voltage range exceeds the upper limit of the safety constraint, posing a risk of exceeding the limit; the red rectangle representing the line power range significantly exceeds the blue circle representing the capacity constraint in the direction of line active power, indicating a severe active power-dominated overload. Under the effect of the strategy, the lower bound of the voltage range remains basically unchanged, while the upper bound of the voltage range is reduced and returns to the range of the safety constraint; the lower bound of the line active power range remains basically unchanged, while the upper bound shrinks significantly, and the rectangular area returns to the range of the capacity constraint. Therefore, the strategy-guided method can effectively reduce the risk of voltage exceeding the limit and the risk of line overload at the prediction level, retaining a certain safety margin, thus verifying its active regulation capability.

[0159] Figure 9 This demonstrates the expected regulatory effect on the overall network status under the action of a strategy according to a specific embodiment of this application.

[0160] Figure 9 Tables 910 and 920 respectively present the expected upper and lower bounds of the voltage ranges of each node and the upper limit of the apparent power range of each line before and after the control strategy. It can be seen that before the control, the upper bound of the voltage range of some nodes exceeded the safe limit, with node 72 exhibiting the most severe voltage exceedance; the upper limit of the apparent power range of some lines exceeded the capacity constraint, posing varying degrees of overload risk, with line 10 exhibiting the most severe overload. Therefore, node 72 and line 10 were identified as vulnerable states. After the control, the lower bound of the voltage range of each node remained unchanged, while the upper bounds of the ranges were reduced, restoring all voltage ranges to within the safe constraint range; the upper bound of the apparent power range of each line decreased, while maintaining a certain distance from the safe constraint. Therefore, the judgment result of the system's over-limit risk after the control changed from over-limit to no over-limit, indicating that the selected strategy can not only alleviate over-limit risks in vulnerable states but also effectively reduce the overall over-limit risk level of the entire network.

[0161] This application, based on a selected high-proportion distributed photovoltaic (PV) power distribution system, inputs the time-series data of the system's operation intervals; analyzes the one-dimensional geometric relationship between node voltage intervals and safety constraints, and the two-dimensional geometric relationship between line power intervals and capacity constraints, deriving three over-limit models for node voltage and three overload models for line power; calculates state-level node voltage over-limit risk indicators and line overload risk indicators, deriving system-level weak over-limit risk indicators and weighted over-limit risk indicators; classifies and warns of system over-limit risks, obtaining three levels of system over-limit risk: no over-limit, warning, and over-limit; finally, classifies control strategies, analyzes the over-limit types and degrees of states, guides the selection of control strategies, obtains the expected effects under the strategy, and outputs a guidance scheme for control strategies. This application addresses the challenge of over-limit risk assessment, fully utilizes the time-series data of the power distribution system's operation intervals, analyzes the geometric relationship between state intervals and safety constraints, constructs an over-limit risk indicator system, provides graded and warn of system over-limit risks, and guides the selection of control strategies, achieving a systematic connection between risk identification, location, and control, thereby enhancing the ability to prevent over-limit risks and improving the level of system safety operation.

[0162] Based on the above-mentioned method for assessing the risk of exceeding limits in power distribution systems, this application also provides a device for assessing the risk of exceeding limits in power distribution systems. The following will be combined with... Figure 10 The device is described in detail.

[0163] Figure 10 A structural block diagram of a power distribution system over-limit risk assessment device according to an embodiment of this application is shown.

[0164] like Figure 10 As shown, the power distribution system over-limit risk assessment device 1000 of this embodiment includes a range determination module 1010, an over-limit determination module 1020, an overload determination module 1030, a risk assessment module 1040, an index determination module 1050, and a result determination module 1060.

[0165] The interval determination module 1010 is used to determine the node voltage interval of each node and the line active power interval and line reactive power interval of each line based on the node voltage time-series data of each node and the line active power time-series data and the line reactive power time-series data of each line during the operation of the power distribution system. In one embodiment, the interval determination module 1010 can be used to perform the operation S210 described above, which will not be repeated here.

[0166] The limit exceedance determination module 1020 is used to determine the limit exceedance type of a node's voltage by analyzing the first positional relationship between the node's voltage range and the voltage safety constraint range. In one embodiment, the limit exceedance determination module 1020 can be used to perform the operation S220 described above, which will not be repeated here.

[0167] The overload determination module 1030 is used to determine the overload type of the line power by analyzing the second positional relationship between the line power range and the capacity constraint range. The line power range is determined based on the line active power range and the line reactive power range. In one embodiment, the overload determination module 1030 can be used to perform the operation S230 described above, which will not be repeated here.

[0168] The risk assessment module 1040 is used to determine the node voltage over-limit risk index of each node and the line overload risk index of each line by using the over-limit assessment method corresponding to the over-limit type and the overload assessment method corresponding to the overload type, respectively. In one embodiment, the risk assessment module 1040 can be used to perform the operation S240 described above, which will not be repeated here.

[0169] The indicator determination module 1050 is used to determine the overall over-limit risk indicator of the power distribution system based on the node voltage over-limit risk indicator of each node and the line overload risk indicator of each line. In one embodiment, the indicator determination module 1050 can be used to perform the operation S250 described above, which will not be repeated here.

[0170] The result determination module 1060 is used to determine the over-limit risk assessment result for the power distribution system based on the overall over-limit risk index. In one embodiment, the result determination module 1060 can be used to perform the operation S260 described above, which will not be repeated here.

[0171] According to an embodiment of this application, the limit determination module 1020 includes a one-dimensional mapping submodule, a first limit determination submodule, a second limit determination submodule, and a third limit determination submodule.

[0172] The one-dimensional mapping submodule is used to map the node voltage range and voltage safety constraint range of a node to a one-dimensional space respectively. In the one-dimensional space, the lower and upper bounds of the node voltage range and the lower and upper bounds of the voltage safety constraint range are compared to determine the first positional relationship between the node voltage range and the voltage safety constraint range.

[0173] The first limit determination submodule is used to determine the limit type as no limit when the voltage safety constraint interval characterized by the first position relationship includes the node voltage interval.

[0174] The second limit exceedance determination submodule is used to determine the limit exceedance type as lower limit exceedance when the lower bound of the node voltage range characterized by the first positional relationship is less than the lower bound of the voltage safety constraint range.

[0175] The third limit exceedance determination submodule is used to determine the limit exceedance type as exceeding the upper limit when the upper bound of the node voltage range characterized by the first positional relationship is greater than the upper limit of the voltage safety constraint range.

[0176] According to an embodiment of this application, the overload determination module 1030 includes a two-dimensional mapping submodule, a position determination submodule, a first overload determination submodule, a second overload determination submodule, and a third overload determination submodule.

[0177] The two-dimensional mapping submodule is used to map the line power range and capacity constraint range to two-dimensional space respectively. The line power range is a rectangular area composed of the line active power range and the line reactive power range, and the capacity constraint range is a circular area with the origin as the center and the maximum apparent power constraint value as the radius.

[0178] The position determination submodule is used to compare multiple vertices of the line power range with a circular region in two-dimensional space to determine the second positional relationship between the line power range and the capacity constraint range.

[0179] The first overload determination submodule is used to determine the overload type as no overload when all vertices are located inside the circular region.

[0180] The second overload determination submodule is used to determine the overload type as apparent power overload only when at least one vertex is located outside the circular region and the absolute value of the active power represented by all vertices is less than the radius of the circular region.

[0181] The third overload determination submodule is used to determine the overload type as active power-dominated apparent power overload when the absolute value of the active power represented by at least one vertex is greater than or equal to the radius of the circular region.

[0182] According to an embodiment of this application, the risk assessment module 1040 includes a first assessment submodule, a second assessment submodule, and a third assessment submodule.

[0183] The first evaluation submodule is used to determine the first voltage over-limit risk index for the over-limit type when the over-limit type is over-lower limit, based on the lower limit of the node voltage range and the lower limit of the voltage safety constraint range, and use it as the node voltage over-limit risk index.

[0184] The second assessment submodule is used to determine the second voltage over-limit risk index for the over-limit type when the over-limit type is over-upper limit, based on the upper bound of the node voltage range and the upper limit of the voltage safety constraint range, and use it as the node voltage over-limit risk index.

[0185] The third evaluation submodule is used to determine the maximum value of the first voltage over-limit risk index and the second voltage over-limit risk index as the node voltage over-limit risk index when the over-limit type includes both over-limit and over-limit.

[0186] According to embodiments of this application, the risk assessment module 1040 further includes a fourth assessment submodule and a fifth assessment submodule.

[0187] The fourth evaluation submodule is used to determine the first line overload risk index for the apparent power overload type when the overload type is apparent power overload only, based on the maximum distance between each vertex and the origin and the maximum apparent power constraint value, and to serve as the line overload risk index.

[0188] The fifth evaluation submodule is used to determine the second line overload risk index for active power-dominated apparent power overload when the overload type is active power-dominated apparent power overload, based on the maximum value of the absolute value of active power represented by multiple vertices and the maximum apparent power constraint value, and to serve as the line overload risk index.

[0189] According to an embodiment of this application, the overall limit exceedance risk index includes a weak limit exceedance risk index and a weighted limit exceedance risk index; the index determination module 1050 includes a weak determination submodule and a weighted determination submodule.

[0190] The weak point identification submodule is used to determine the overall weak point risk indicators of the power distribution system based on the maximum value of the node voltage over-limit risk indicator and the node number corresponding to the maximum value of the node voltage over-limit risk indicator, as well as the maximum value of the line overload risk indicator and the line number corresponding to the maximum value of the line overload risk indicator.

[0191] The weighted determination submodule is used to perform weighted fusion of the node voltage over-limit risk index of each node and the line overload risk index of each line to determine the overall weighted over-limit risk index of the power distribution system.

[0192] According to an embodiment of this application, the overall over-limit risk index of the power distribution system includes a weighted over-limit risk index, which is obtained by weighting and fusing the node voltage over-limit risk index of each node and the line overload risk index of each line. The result determination module 1060 includes a first result determination submodule, a second result determination submodule, and a third result determination submodule.

[0193] The first result determination submodule is used to determine the over-limit risk assessment result characterizing the over-limit of the power distribution system when the weighted over-limit risk index is higher than the preset risk threshold.

[0194] The second result determination submodule is used to determine the over-limit risk assessment result to characterize the existence of over-limit risk in the power distribution system when the weighted over-limit risk index is not higher than the preset risk threshold and is greater than zero.

[0195] The third result determination submodule is used to determine the over-limit risk assessment result to characterize whether the power distribution system exceeds the limits when the weighted over-limit risk index is zero.

[0196] According to an embodiment of this application, the interval determination module 1010 includes a first interval determination submodule and a second interval determination submodule.

[0197] The first interval determination submodule is used to determine the node voltage interval for each node by taking the minimum and maximum values ​​of the node's time series data as the lower and upper bounds of the node voltage interval, respectively.

[0198] The second interval determination submodule is used to determine the line active power interval and line reactive power interval for each line by taking the minimum and maximum values ​​of the line active power time series data as the lower and upper bounds of the line active power interval, respectively, and taking the minimum and maximum values ​​of the line reactive power time series data as the upper and lower bounds of the line reactive power interval, respectively.

[0199] According to embodiments of this application, any multiple modules among the interval determination module 1010, limit exceedance determination module 1020, overload determination module 1030, risk assessment module 1040, indicator determination module 1050, and result determination module 1060 can be combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least some of the functions of one or more of these modules can be combined with at least some of the functions of other modules and implemented in one module. According to embodiments of this application, at least one of the interval determination module 1010, limit exceedance determination module 1020, overload determination module 1030, risk assessment module 1040, indicator determination module 1050, and result determination module 1060 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging the circuitry, or implemented in any one of the three implementation methods of software, hardware, and firmware, or in a suitable combination of any of these. Alternatively, at least one of the interval determination module 1010, the limit determination module 1020, the overload determination module 1030, the risk assessment module 1040, the indicator determination module 1050, and the result determination module 1060 can be at least partially implemented as a computer program module, which can perform the corresponding function when the computer program module is run.

[0200] Figure 11 A block diagram of an electronic device suitable for implementing a method for assessing the risk of exceeding limits in a power distribution system, according to an embodiment of this application, is shown.

[0201] like Figure 11As shown, an electronic device 1100 according to an embodiment of this application includes a processor 1101, which can perform various appropriate actions and processes according to a program stored in a ROM 1102 or a program loaded from a storage portion 1108 into a RAM 1103, where ROM represents read-only memory and RAM represents random access memory. The processor 1101 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1101 may also include onboard memory for caching purposes. The processor 1101 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of this application.

[0202] RAM 1103 stores various programs and data required for the operation of electronic device 1100. Processor 1101, ROM 1102, and RAM 1103 are interconnected via bus 1104. Processor 1101 executes various operations of the method flow according to embodiments of this application by executing programs in ROM 1102 and / or RAM 1103. It should be noted that programs may also be stored in one or more memories other than ROM 1102 and RAM 1103. Processor 1101 may also execute various operations of the method flow according to embodiments of this application by executing programs stored in one or more memories.

[0203] According to embodiments of this application, the electronic device 1100 may further include an input / output (I / O) interface 1105, which is also connected to a bus 1104. The electronic device 1100 may also include one or more of the following components connected to the input / output (I / O) interface 1105: an input section 1106 including a keyboard, mouse, etc.; an output section 1107 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 1108 including a hard disk, etc.; and a communication section 1109 including a network interface card such as a LAN card, modem, etc. The communication section 1109 performs communication processing via a network such as the Internet. A drive 1110 is also connected to the input / output (I / O) interface 1105 as needed. A removable medium 1111, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 1110 as needed so that computer programs read from it can be installed into the storage section 1108 as needed.

[0204] This application also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of this application.

[0205] According to embodiments of this application, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of this application, the computer-readable storage medium may include ROM 1102 and / or RAM 1103 and / or one or more memories other than ROM 1102 and RAM 1103 described above.

[0206] Embodiments of this application also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code enables the computer system to implement the power distribution system over-limit risk assessment method provided in the embodiments of this application.

[0207] When the computer program is executed by the processor 1101, it performs the functions defined in the system / apparatus of this application embodiment. According to the embodiments of this application, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0208] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 1109, and / or installed from the removable medium 1111. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0209] In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 1109, and / or installed from the removable medium 1111. When the computer program is executed by the processor 1101, it performs the functions defined in the system of this application embodiment. According to the embodiments of this application, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0210] According to embodiments of this application, program code for executing the computer programs provided in the embodiments of this application can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0211] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0212] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

[0213] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of this application, those skilled in the art can make various substitutions and modifications, all of which should fall within the scope of this application.

Claims

1. A method for assessing the risk of exceeding limits in a power distribution system, characterized in that, The method includes: Based on the node voltage time sequence data of each node and the line active power time sequence data and line reactive power time sequence data of each line during the operation of the power distribution system, the node voltage range of each node and the line active power range and line reactive power range of each line are determined respectively. By analyzing the first positional relationship between the node voltage range and the voltage safety constraint range of the node, the over-limit type of the node voltage is determined. By analyzing the second positional relationship between the line power range and the capacity constraint range of the line, the overload type of the line power is determined. The line power range is determined based on the line active power range and the line reactive power range. The second positional relationship is determined as follows: the line power range and the capacity constraint range are respectively mapped to a two-dimensional space. The line power range is a rectangular area composed of the line active power range and the line reactive power range. The capacity constraint range is a circular area with the origin as the center and the maximum apparent power constraint value as the radius. In the two-dimensional space, multiple vertices of the line power range are compared with the circular area to determine the second positional relationship between the line power range and the capacity constraint range. The node voltage over-limit risk index and the line overload risk index of each node are determined by using the over-limit assessment method corresponding to the over-limit type and the overload assessment method corresponding to the overload type, respectively. Based on the node voltage over-limit risk index of each node and the line overload risk index of each line, the overall over-limit risk index of the power distribution system is determined. Based on the overall over-limit risk index, the over-limit risk assessment result for the power distribution system is determined.

2. The method according to claim 1, characterized in that, The analysis of the first positional relationship between the node's voltage range and the voltage safety constraint range includes: The node voltage range and voltage safety constraint range of the node are mapped to a one-dimensional space respectively. The lower and upper bounds of the node voltage range and the lower and upper bounds of the voltage safety constraint range are compared in the one-dimensional space to determine the first positional relationship between the node voltage range and the voltage safety constraint range. When the first positional relationship indicates that the voltage safety constraint interval includes the node voltage interval, the over-limit type is determined to be non-over-limit; If the lower bound of the node voltage range characterized by the first positional relationship is less than the lower limit of the voltage safety constraint range, the over-limit type is determined to be over-limit. If the upper bound of the node voltage range, as characterized by the first positional relationship, is greater than the upper limit of the voltage safety constraint range, then the over-limit type is determined to be over-limit.

3. The method according to claim 1, characterized in that, Determining the overload type of the line power of the line includes: If all the vertices are located inside the circular region, the overload type is determined to be no overload. If at least one of the vertices is located outside the circular region and the absolute value of the active power represented by all the vertices is less than the radius of the circular region, the overload type is determined to be apparent power overload only. If the absolute value of the active power represented by at least one of the vertices is greater than or equal to the radius of the circular region, the overload type is determined to be an active power-dominated apparent power overload.

4. The method according to claim 2, characterized in that, Determine the node voltage over-limit risk indicators for each of the aforementioned nodes, including: When the over-limit type is the lower limit over-limit, the first voltage over-limit risk index of the lower limit over-limit type is determined based on the lower limit of the node voltage range and the lower limit of the voltage safety constraint range, and is used as the node voltage over-limit risk index. When the over-limit type is over-upper limit, a second voltage over-limit risk index for the over-upper limit type is determined based on the upper limit of the node voltage range and the upper limit of the voltage safety constraint range, and is used as the node voltage over-limit risk index. When the over-limit type includes both over-limit and over-limit, the maximum value of the first voltage over-limit risk index and the second voltage over-limit risk index is determined as the node voltage over-limit risk index.

5. The method according to claim 3, characterized in that, Determine the line overload risk indicators for each of the aforementioned lines, including: In the case of overload type only apparent power overload, the first line overload risk index of the only apparent power overload type is determined based on the maximum distance between each vertex and the origin and the maximum apparent power constraint value, and is used as the line overload risk index. In the case of active power-dominated apparent power overload, a second line overload risk index for active power-dominated apparent power overload is determined based on the maximum absolute value of active power represented by multiple vertices and the maximum apparent power constraint value, and is used as the line overload risk index.

6. The method according to claim 1, characterized in that, The overall limit violation risk index includes a weak limit violation risk index and a weighted limit violation risk index; The determination of the overall over-limit risk index of the power distribution system based on the node voltage over-limit risk index of each node and the line overload risk index of each line includes: Based on the maximum value of the node voltage over-limit risk index and the node number corresponding to the maximum value of the node voltage over-limit risk index, as well as the maximum value of the line overload risk index and the line number corresponding to the maximum value of the line overload risk index, the overall weak over-limit risk index of the power distribution system is determined. The node voltage over-limit risk index of each node and the line overload risk index of each line are weighted and fused to determine the overall weighted over-limit risk index of the power distribution system.

7. The method according to claim 1, characterized in that, The overall over-limit risk index of the power distribution system includes a weighted over-limit risk index, which is obtained by weighting and fusing the node voltage over-limit risk index of each node and the line overload risk index of each line. The step of determining the over-limit risk assessment result for the power distribution system based on the overall over-limit risk index includes: If the weighted limit exceedance risk index is higher than a preset risk threshold, the limit exceedance risk assessment result is determined to characterize the limit exceedance of the power distribution system. If the weighted limit exceedance risk index is not higher than the preset risk threshold and is greater than zero, the limit exceedance risk assessment result is determined to indicate that the power distribution system has a limit exceedance risk. When the weighted limit exceedance risk index is zero, the limit exceedance risk assessment result indicates that the power distribution system does not exceed the limit.

8. The method according to claim 1, characterized in that, The step of determining the node voltage range of each node and the line active power range and line reactive power range of each line based on the node voltage time-series data of each node and the line active power time-series data of each line during the operation of the power distribution system includes: For each node, the minimum and maximum values ​​of the node's timing data are used as the lower and upper bounds of the node's voltage range, respectively, to obtain the node's voltage range. For each of the aforementioned lines, the minimum and maximum values ​​of the line's active power time-series data are respectively used as the lower and upper bounds of the line's active power interval, and the minimum and maximum values ​​of the line's reactive power time-series data are respectively used as the lower and upper bounds of the line's reactive power interval, thus obtaining the line's active power interval and line reactive power interval.

9. An electronic device, comprising: One or more processors; Memory, used to store one or more computer programs. The characteristic feature is that the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1 to 8.

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