A method and system for simplifying network security constraints based on a boundary method

Abstract

The application discloses a method and system for simplifying network security constraints based on a boundary method, and belongs to the technical field of power system operation and dispatching. The application provides a method for simplifying network security constraints based on a boundary method, which comprises the following steps: obtaining network security linear constraints; dividing the injection power variable serial numbers of all nodes into different sets; determining the injection power of each node according to the sets; based on the injection power of each node, calculating the maximum and minimum values of the line flow of each line; comparing the maximum value of the line flow of each line with the positive line transmission limit, and comparing the minimum value of the line flow of each line with the negative line transmission limit, to determine whether the network security constraints of each line are redundant constraints, and if yes, the redundant constraints are removed, and if not, the redundant constraints are reserved. The application removes the redundant network security constraints of a power system based on a boundary method, and is helpful to the solution of models in a power spot market and operation and dispatching.

Description

Technical Field

[0001] This invention relates to the field of power system operation and scheduling technology, and more specifically, to a method and system for simplifying network security constraints based on the boundary method. Background Technology

[0002] The Network Constrained Unit Commitment (NCUC) problem is a key to achieving optimal allocation of power resources and has wide applications in the electricity spot market and operation dispatch.

[0003] NCUC is essentially a large-scale optimization problem involving linear and nonlinear constraints. As the scale of power systems expands, the number of variables and constraints in the model increases significantly. At the same time, to ensure the safe and stable operation of the power system network, a large number of linear constraints need to be considered in the model, which affects the solution rate of NCUC problems and is not conducive to applications in areas such as the electricity spot market and operation scheduling. Summary of the Invention

[0004] To address the above problems, this invention proposes a method for simplifying network security constraints based on the boundary method, comprising:

[0005] Based on the boundary method, the network security constraints in the power system model are described as linear constraints to obtain the linear constraints of network security.

[0006] Based on the linear constraints of network security, the generator transfer distribution factor of each node in the power system to each line is determined. According to the positive or negative sign of the generator transfer distribution factor, the injected power variable index of each node is divided into different sets.

[0007] The injection power of each node is determined based on the set, and the maximum and minimum values ​​of the power flow of each line are calculated based on the injection power of each node.

[0008] By comparing the maximum power flow of each line with the positive line transmission limit, and comparing the minimum power flow of each line with the negative line transmission limit, it is determined whether the network security constraints of each line are redundant constraints. If so, they are removed; otherwise, they are retained.

[0009] Optionally, determining the injection power of each node based on the set includes:

[0010] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the maximum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the minimum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0011] Optionally, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the maximum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the minimum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the maximum value of the power flow of each line is calculated based on the injected power injected into each node.

[0012] Optionally, determining the injection power of each node based on the set includes:

[0013] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the minimum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the maximum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0014] Optionally, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the minimum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the maximum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the minimum value of the power flow of each line is calculated based on the injected power injected into each node.

[0015] Optionally, if the maximum value of the line power flow is less than or equal to the positive line transmission limit, and the minimum value of the line power flow is greater than or equal to the negative line transmission limit, the network security constraint of the line is a redundancy constraint.

[0016] Furthermore, this invention also proposes a system for simplifying network security constraints based on the boundary method, comprising:

[0017] The simplified element is used to describe the network security constraints in the power system model as linear constraints based on the boundary method, so as to obtain the linear constraints of network security.

[0018] The first calculation unit is used to determine the generator transfer distribution factor of each node in the power system to each line based on the linear constraints of network security, and to divide the injected power variable index of each node into different sets according to the positive or negative sign of the generator transfer distribution factor.

[0019] The second calculation unit is used to determine the injection power of each node according to the set, and calculate the maximum and minimum values ​​of the power flow of each line based on the injection power of each node.

[0020] The simplified unit is used to determine whether the network security constraints of each line are redundant constraints by comparing the maximum value of the power flow of each line with the positive line transmission limit, and comparing the minimum value of the power flow of each line with the negative line transmission limit. If so, the constraints are removed; otherwise, they are retained.

[0021] Optionally, determining the injection power of each node based on the set includes:

[0022] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the maximum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the minimum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0023] Optionally, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the maximum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the minimum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the maximum value of the power flow of each line is calculated based on the injected power injected into each node.

[0024] Optionally, determining the injection power of each node based on the set includes:

[0025] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the minimum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the maximum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0026] Optionally, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the minimum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the maximum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the minimum value of the power flow of each line is calculated based on the injected power injected into each node.

[0027] Optionally, if the maximum value of the line power flow is less than or equal to the positive line transmission limit, and the minimum value of the line power flow is greater than or equal to the negative line transmission limit, the network security constraint of the line is a redundancy constraint.

[0028] In another aspect, the present invention also provides a computing device, comprising: one or more processors;

[0029] A processor is used to execute one or more programs;

[0030] When the one or more programs are executed by the one or more processors, the method described above is implemented.

[0031] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method described above.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] This invention provides a method for simplifying network security constraints based on the boundary method, comprising: describing network security constraints in a power system model as linear constraints based on the boundary method to obtain linear network security constraints; determining the generator transfer distribution factor of each node to each line based on the linear network security constraints; dividing the injected power variable index of each node into different sets according to the positive or negative nature of the generator transfer distribution factor; determining the injected power of each node based on the sets; calculating the maximum and minimum power flow values ​​of each line based on the injected power of each node; and determining whether the network security constraints of each line are redundant by comparing the maximum power flow value of each line with the positive line transmission limit and the minimum power flow value of each line with the negative line transmission limit. If so, the redundancy is removed; otherwise, it is retained. This invention removes redundant network security constraints in power systems based on the boundary method, which is helpful for solving models in the power spot market and operation scheduling. Attached Figure Description

[0034] Figure 1 This is a flowchart of the method of the present invention;

[0035] Figure 2 This is a flowchart of an embodiment of the method of the present invention;

[0036] Figure 3 This is a structural diagram of the system of the present invention. Detailed Implementation

[0037] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0038] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0039] Example 1:

[0040] This invention proposes a method for simplifying network security constraints based on the boundary method, such as... Figure 1 As shown, it includes:

[0041] Step 1: Based on the boundary method, describe the network security constraints in the power system model as linear constraints to obtain the linear constraints of network security.

[0042] Step 2: Based on the linear constraints of network security, determine the generator transfer distribution factor of each node in the power system to each line, and divide the injected power variable index of each node into different sets according to the positive and negative signs of the generator transfer distribution factor.

[0043] Step 3: Determine the injection power of each node based on the set, and calculate the maximum and minimum power flow of each line based on the injection power of each node.

[0044] Step 4: By comparing the maximum value of the power flow of each line with the positive line transmission limit, and comparing the minimum value of the power flow of each line with the negative line transmission limit, determine whether the network security constraints of each line are redundant constraints. If so, remove them; otherwise, retain them.

[0045] The determination of the injection power for each node based on the set includes:

[0046] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the maximum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the minimum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0047] Wherein, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the maximum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the minimum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the maximum value of the power flow of each line is calculated based on the injected power injected into each node.

[0048] The determination of the injection power for each node based on the set includes:

[0049] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the minimum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the maximum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0050] Wherein, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the minimum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the maximum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the minimum value of the power flow of each line is calculated based on the injected power injected into each node.

[0051] Where the maximum value of the line power flow is less than or equal to the positive line transmission limit, and the minimum value of the line power flow is greater than or equal to the negative line transmission limit, the network security constraint of the line is a redundancy constraint.

[0052] The present invention will be further described below with reference to embodiments:

[0053] The unit combination model determines the start-up and shutdown status of each unit at various times. It is the foundation and prerequisite for the entire power generation plan and is related to the load balance of the power grid and the arrangement of ancillary service plans such as frequency regulation and reserve. Its quality will directly affect the safety and economic benefits of the power grid's power generation plan.

[0054] The NCUC model typically considers power balance constraints, unit start-up and shutdown times, unit duration, minimum unit downtime constraints, upper and lower limits of unit output constraints, unit ramp-up constraints, and network constraints.

[0055] First, the boundary method used in this invention will be explained:

[0056] Boundary method

[0057] The boundary method is a method for identifying redundant constraints in a bounded variable linear programming problem. The main idea of ​​the boundary method is to calculate the upper and lower limits of each constraint and compare them with the right side of the constraint to determine whether it is a redundant constraint.

[0058] The general form of a linear programming problem with bounded variables is as follows:

[0059]

[0060] In the formula, f is the objective function value, and x j c is a bounded variable. jThe coefficients of the bounded variable; a ij To constrain variable x in i j The coefficient, b i d represents the limit value of constraint i; j and u j The variables x are respectively j The lower and upper bounds.

[0061] Determine linear constraints The steps to determine if a constraint is redundant are as follows:

[0062] (1) Based on the variable coefficient a in the constraints ij The sign of the variable j divides the variable index j into two sets P. i and N i :

[0063] P i ={j|a ij >0} (2)

[0064] Q i ={j|a ij <0} (3)

[0065] (2) Calculate the upper and lower bounds for each constraint. For constraint i:

[0066]

[0067]

[0068] (3) Determine U i Does U satisfy i <b i If i = 1, 2, ..., m, and the constraint is satisfied, then constraint i is a redundant constraint and should be removed; otherwise, constraint i should be retained.

[0069] Secondly, the network constraints will be explained:

[0070] The following section uses network constraints as an example to introduce the specific implementation steps of the constraint simplification method for unit combination optimization based on the boundary method when simplifying network constraints.

[0071] In power system analysis, the generation transfer distribution factor (GSDF) is defined as the change in active power flow in a branch caused by a unit increase in the active power output of a generator. For DC power flow, the GSDF of generator node i with respect to branch l is:

[0072]

[0073] In the formula, SF l-i ΔP is the power generation transfer distribution factor from generator node i to branch l. GiLet ΔP be the change in active power output at generator node i. l X represents the change in active power flow in branch l; mi and X ni These are the values ​​of the elements in the m-th row and i-th column of the system reactance matrix, respectively; x l Let be the reactance value of branch l.

[0074] It is evident that GSDF defines the impact of generator active power output changes on branch active power flow in an incremental manner. According to equation (22), the active power flow of branch l can be described as:

[0075]

[0076] In the formula, P l For the active power flow of branch l, P i Let P be the injected power at node i. It's important to note that if node i is a load node, it needs to be treated as a negative generator node. i Take the negative value of the load on node i.

[0077] Therefore, the network security constraints in the model can be described as linear constraints as follows:

[0078]

[0079] In the formula, SF l-i PG is the power generation transfer distribution factor of node i to line l; i,t Inject power into the generator at node i in time period t; Load i,t P represents the load injection power at node i in time period t, and is taken as a positive value. limit This represents the transmission limit of the line.

[0080] Next, the simplified network constraints using the boundary method will be explained:

[0081] Network security constraints, as multivariate linear constraints, share the same characteristics as linear constraints in linear programming problems. Since power flow may exhibit both forward and reverse directions, the network security constraints described in equation (8) require consideration of lower limits compared to linear constraints in linear programming problems. Therefore, when simplifying network security constraints using the boundary method, a comprehensive comparison of the maximum and minimum possible values ​​of the constraints with the upper and lower limits should be considered. Specific steps are as follows: Figure 2 As shown, it includes:

[0082] Step 1: Calculate the transfer distribution factor SF of each node in the system to each branch. l-i .

[0083] Step 2: Divide the node-injected power variable index i into different sets based on the sign of the generator transfer distribution factor:

[0084] P l ={i|SF l-i >0} (9)

[0085] Q l ={i|SF l-i <0} (10)

[0086] Step 3: Determine the injected power at node i and calculate the maximum possible power flow value for line l. For generator node i, if the transfer distribution factor SF l-i If positive, the node injection power is P. Gimax If the transition distribution factor SF l-i If negative, the node injection power is P. Gimin For load nodes, the injected power is the negative of the corresponding load value, -P. d The maximum possible power flow value P of line l is obtained according to equation (7). lmax .

[0087] Step 4: Determine the injected power at node i and calculate the minimum possible power flow value for line l. For generator node i, if the transfer distribution factor SF l-i If positive, the node injection power is P. Gimin If the transition distribution factor SF l-i If negative, the node injection power is P. Gimax For load nodes, the injected power is the negative of the corresponding load value, -P. d And find the minimum possible power flow value P of line l. lmin .

[0088] Step 5: Compare P respectively lmax With limit l P lmin with -limit l The size of P. lmax ≤limit l And P lmin ≥-limit l If the condition is met, determine that the safety constraint of line l is a redundant constraint and remove the constraint; otherwise, retain the safety constraint of line l.

[0089] This invention was used to conduct simulation experiments on the IEEE 1354-bus system. The IEEE 1354 system includes 1354 bus nodes, 1991 power lines, 5 regions, and 370 generators. Among them, 66 units are under a self-generating plan, and 304 units are under market bidding. The unit types include thermal power, wind power, solar power, hydropower, and nuclear power, with an installed capacity of approximately 140456.2 MW. After constructing the model, the COPT solver was called to solve the model to verify the effectiveness of the proposed method.

[0090] This test only simplifies the network constraints in the NCUC problem. The example system contains 1427 transmission lines with transmission capacity limits; before simplification, there were 1427 network security constraints to consider per time period. Taking one time period as an example, after filtering and removing redundant constraints using the method presented in this paper, the number of network security constraints is reduced to 73. The possible maximum and minimum values ​​of the power flow constraints and the transmission capacity limits after simplification are shown in Table 1.

[0091] Table 1 Simplified Line Safety Constraints

[0092]

[0093]

[0094] To verify the effectiveness of the proposed method in improving the model solution speed, the solution time of NCUC was tested for two cases: adding network security constraints directly to the model without simplification and adding them to the model after simplifying the network security constraints. The specific data are shown in Table 2.

[0095] Table 2 Solution time of the model before and after simplification

[0096]

[0097] The test results show that after simplifying the network security constraints, the solution time of NCUC was shortened from 392.673s to 59.258s; the solution rate was improved by 84.91%, and the solution efficiency of the NCUC model was greatly optimized.

[0098] Example 2:

[0099] This invention also proposes a system 200 for simplifying network security constraints based on the boundary method, such as... Figure 3 As shown, it includes:

[0100] The simplified element 201 is used to describe the network security constraints in the power system model as linear constraints based on the boundary method, so as to obtain the linear constraints of network security.

[0101] The first calculation unit 202 is used to determine the generator transfer distribution factor of each node in the power system to each line based on the linear constraints of network security, and to divide the injected power variable index of each node into different sets according to the positive and negative signs of the generator transfer distribution factor.

[0102] The second calculation unit 203 is used to determine the injection power of each node according to the set, and calculate the maximum and minimum values ​​of the power flow of each line based on the injection power of each node.

[0103] The simplification unit 204 is used to determine whether the network security constraints of each line are redundant constraints by comparing the maximum value of the power flow of each line with the positive line transmission limit, and comparing the minimum value of the power flow of each line with the negative line transmission limit. If so, the constraints are removed; otherwise, they are retained.

[0104] The determination of the injection power for each node based on the set includes:

[0105] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the maximum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the minimum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0106] Wherein, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the maximum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the minimum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the maximum value of the power flow of each line is calculated based on the injected power injected into each node.

[0107] The determination of the injection power for each node based on the set includes:

[0108] For each node, if the generator transfer distribution factor corresponding to each node is positive, the injected power into each node is the minimum value of the change in active power output of each node; if the generator transfer distribution factor corresponding to each node is negative, the injected power into each node is the maximum value of the change in active power output of each node; if the node is a load node, the injected power into each node is the negative value of the load.

[0109] Wherein, when the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the minimum value of the change in active power output of each node; when the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the maximum value of the change in active power output of each node; when the node is a load node, the injected power injected into each node is the negative value of the load; and the minimum value of the power flow of each line is calculated based on the injected power injected into each node.

[0110] Where the maximum value of the line power flow is less than or equal to the positive line transmission limit, and the minimum value of the line power flow is greater than or equal to the negative line transmission limit, the network security constraint of the line is a redundancy constraint.

[0111] This invention removes redundant network security constraints in power systems based on the boundary method, which is helpful for solving models in the electricity spot market and operation scheduling.

[0112] Example 3:

[0113] Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the methods in the above embodiments.

[0114] Example 4:

[0115] Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiments.

[0116] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0117] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0118] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0119] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0120] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0121] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for simplifying network security constraints based on boundary method, characterized in that, The method includes: Based on the boundary method, the network security constraints in the power system model are described as linear constraints to obtain the linear constraints of network security. Based on the linear constraints of network security, the generator transfer distribution factor of each node in the power system to each line is determined. According to the positive or negative sign of the generator transfer distribution factor, the injected power variable index of each node is divided into different sets. The injection power of each node is determined based on the set, and the maximum and minimum values ​​of the power flow of each line are calculated based on the injection power of each node. By comparing the maximum value of the power flow of each line with the transmission limit of the positive line, and comparing the minimum value of the power flow of each line with the transmission limit of the negative line, it is determined whether the network security constraints of each line are redundant constraints. If so, they are removed; otherwise, they are retained. When the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the maximum value of the change in active power output of each node. When the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the minimum value of the change in active power output of each node. When the node is a load node, the injected power injected into each node is the negative value of the load. The maximum value of the power flow of each line is calculated based on the injected power injected into each node. When the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the minimum value of the change in active power output of each node. When the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the maximum value of the change in active power output of each node. When the node is a load node, the injected power injected into each node is the negative value of the load. The minimum value of the power flow of each line is calculated based on the injected power injected into each node.

2. The method according to claim 1, characterized in that, If the maximum value of the line power flow is less than or equal to the positive line transmission limit, and the minimum value of the line power flow is greater than or equal to the negative line transmission limit, then the network security constraint of the line is a redundancy constraint.

3. A system for simplifying network security constraints based on the boundary method, characterized in that, The system includes: The simplified element is used to describe the network security constraints in the power system model as linear constraints based on the boundary method, so as to obtain the linear constraints of network security. The first calculation unit is used to determine the generator transfer distribution factor of each node in the power system to each line based on the linear constraints of network security, and to divide the injected power variable index of each node into different sets according to the positive or negative sign of the generator transfer distribution factor. The second calculation unit is used to determine the injection power of each node according to the set, and calculate the maximum and minimum values ​​of the power flow of each line based on the injection power of each node. The simplified unit is used to determine whether the network security constraints of each line are redundant constraints by comparing the maximum value of the power flow of each line with the positive line transmission limit, and comparing the minimum value of the power flow of each line with the negative line transmission limit. If so, it is removed; otherwise, it is retained. When the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the maximum value of the change in active power output of each node. When the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the minimum value of the change in active power output of each node. When the node is a load node, the injected power injected into each node is the negative value of the load. The maximum value of the power flow of each line is calculated based on the injected power injected into each node. When the generator transfer distribution factor corresponding to each node is positive, the injected power injected into each node is the minimum value of the change in active power output of each node. When the generator transfer distribution factor corresponding to each node is negative, the injected power injected into each node is the maximum value of the change in active power output of each node. When the node is a load node, the injected power injected into each node is the negative value of the load. The minimum value of the power flow of each line is calculated based on the injected power injected into each node.

4. The system according to claim 3, characterized in that, If the maximum value of the line power flow is less than or equal to the positive line transmission limit, and the minimum value of the line power flow is greater than or equal to the negative line transmission limit, then the network security constraint of the line is a redundancy constraint.

5. A computer device, characterized in that, include: One or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method described in any one of claims 1-2 is implemented.

6. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the method as described in any one of claims 1-2.

Images