Construction method and device of guaranteed-bottom power generation and transmission system, electronic equipment and storage medium

Abstract

The invention relates to the technical field of power system disaster prevention, in particular to a guaranteed power generation and transmission system construction method and device, electronic equipment and a storage medium, and the method comprises the steps: constructing a three-layer guaranteed power grid defense model; setting constraint conditions; a column and constraint generation algorithm is adopted to disassemble the three-layer guaranteed-bottom power grid defense model into a main problem and a sub-problem; and based on the constraint condition, solving the main problem and the sub-problems until the convergence condition is met, and outputting the guaranteed power grid construction model. A guaranteed power grid construction model is established based on the idea of a two-stage robust optimization model, and the guaranteed power grid construction method considering the new energy power generation proportion and line reinforcement is provided by setting constraint conditions such as a basic guaranteed power supply selection constraint, a new energy power generation proportion constraint and a Kirchhoff law constraint. And a more reliable and flexible solution is provided for a power system during high-proportion access of new energy.

Description

Technical Field

[0001] The present application relates to the technical field of disaster prevention of electric power systems, and in particular to methods, devices, electronic equipment and storage media for constructing a guaranteed power generation and transmission system. Background Art

[0003] A major challenge facing renewable energy power generation is extreme weather. Under the "dual carbon goals", the continued large-scale and high-proportion access of renewable energy will bring huge challenges to the balance of supply and demand in the power system. Extreme weather is characterized by high uncertainty and destructiveness. Once it occurs, it may cause large-scale power outages. In order to cope with the above risks, building a guaranteed power grid is a typical measure to improve the resilience of the power system. The core idea is to select important substations, key lines, important loads and disaster-resistant power sources for differentiated power grid construction, and quickly implement it after a disaster occurs, effectively reducing possible losses and meeting the continuous and reliable power supply requirements of core users under extreme conditions.

[0004] However, there is currently no method suitable for building a guaranteed power grid when a high proportion of new energy is connected, so there is an urgent need for a method to build a guaranteed power generation and transmission system. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems that there is currently no method suitable for building a guaranteed power grid when a high proportion of new energy is connected.

[0006] To this end, the present application provides a method for constructing a guaranteed power generation and transmission system. A guaranteed power grid construction model is established based on the idea of ​​a two-stage robust optimization model. By setting constraints such as basic guaranteed power source selection constraints, renewable energy power generation proportion constraints, and Kirchhoff's law constraints, a guaranteed power grid construction method that considers the proportion of renewable energy power generation and line reinforcement is proposed, which provides a more reliable and flexible solution for the power system when a high proportion of renewable energy is connected.

[0007] The present application also provides a device for constructing a guaranteed power transmission system, an electronic device and a storage medium including the above-mentioned method for constructing a guaranteed power transmission system.

[0008] A method for constructing a guaranteed power transmission system according to an embodiment of the first aspect of the present application includes:

[0009] Construct a three-layer bottom-line power grid defense model;

[0010] Set constraints, which include at least one or more of the following: basic power supply selection constraints, renewable energy power generation ratio constraints, and Kirchhoff's law constraints;

[0011] The three-layer guaranteed power grid defense model is decomposed into main problems and sub-problems by using the column and constraint generation algorithm;

[0012] Based on the constraints, solve the main problem and sub-problems until the convergence conditions are met, and output the minimum power grid construction model.

[0013] Optionally, the steps for building a three-layer bottom-line grid defense model include:

[0014] Build the first layer of defenders to select the backup grid and selectively reinforce the lines within the backup grid to minimize the shedding of important loads;

[0015] Construct a second layer of attackers to formulate disaster attack strategies for the backup power grid and reinforced lines selected by the first layer of defenders;

[0016] The third layer of defenders is constructed to optimize the power flow of the second layer of attackers, so as to minimize the expected value of load shedding loss under the disaster attack strategy.

[0017] Optionally, the steps of using the column and constraint generation algorithm to decompose the three-layer guaranteed power grid defense model into a main problem and sub-problems include:

[0018] The second-layer attacker and the third-layer defender are combined as a sub-problem. The sub-problem is used to solve the disaster attack strategy given by the combination of the second-layer attacker and the third-layer defender, and the disaster attack strategy is returned to the main problem in each iteration;

[0019] The first-layer defender is taken as the main problem. The main problem is used to solve the bottom-line power grid selection plan and line reinforcement plan given by the first-layer defender based on the set of attack plans composed of disaster attack strategies.

[0020] Optionally, based on the constraint conditions, solving the main problem and the sub-problems until the convergence conditions are met and outputting the guaranteed power grid construction model includes:

[0021] Initialize the lower bound, upper bound, number of iterations, and attack plan set;

[0022] Based on the constraints, solve the main problem, obtain the first solution value and the bottom-line grid selection plan and line reinforcement plan given by the first-layer defender; use the first solution value to update the lower bound;

[0023] Based on the constraints, solve the subproblem to obtain the second solution value and the disaster attack strategy; use the second solution value to update the upper bound, add the disaster attack strategy to the attack plan set, and update the constraints;

[0024] Based on the updated constraints, the iteration is repeated to solve the main problem and sub-problems until the convergence conditions are met. The minimum grid selection plan and line reinforcement plan given by the first-layer defender obtained by solving the main problem after the convergence conditions are met are output as a minimum grid construction model.

[0025] Optionally, the basic guaranteed power selection constraints are:

[0026]

[0027] Among them, S represents the set of conventional generator sets that are the basic power supply of the transmission network, N is the set of all nodes in the power grid, and P n is the load of node n; P g represents the active output of generator g; u s A binary variable indicating whether the power source s is in operation; u n A binary variable indicating whether node n is selected into the guaranteed power grid.

[0028] Optionally, the renewable energy power generation ratio constraint is:

[0029]

[0030] Among them, S N is the set of renewable energy generating units, μ represents the proportion of renewable energy generating output in the power grid; P g represents the active output of generator g; u s A binary variable indicating whether power source s is operational.

[0031] Optionally, Kirchhoff's law constraints are:

[0032]

[0033] Where, l represents the transmission line; u l Indicates whether the line is included in the guaranteed power grid, u l =1 means including, u l =0 means ignored; (z l +v l -z l v l ) represents the line reinforcement variable z l and the attack variable v l If z l =1, it means that line l is reinforced; if z l =0, it means that line l is not protected; if v l =0, it means line l is attacked; if v l =1, it means line l is not attacked; P l represents the active power transmitted by line l; θ o(l) represents the voltage phase angle of the source node of line l; θ d(l) represents the voltage phase angle of the target node of line l; L represents the set of lines in the system.

[0034] According to a second aspect of the present application, a device for constructing a guaranteed power transmission system includes:

[0035] Building modules for constructing a three-layer bottom-line grid defense model;

[0036] The constraint module is used to set constraint conditions, which include at least one or more of the following: basic power supply selection constraint, renewable energy power generation proportion constraint and Kirchhoff's law constraint;

[0037] A disassembly module, which is used to disassemble the three-layer guaranteed power grid defense model into main problems and sub-problems using a column and constraint generation algorithm;

[0038] The output module is used to solve the main problem and sub-problems based on the constraints until the convergence conditions are met and output the minimum power grid construction model.

[0039] An electronic device according to an embodiment of the third aspect of the present application includes:

[0040] A processor and a memory, the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method of the first aspect.

[0041] A computer-readable storage medium according to an embodiment of the fourth aspect of the present application is used to store a computer program, and the computer program enables a computer to execute the method of the first aspect.

[0042] One of the above technical solutions has at least the following advantages or beneficial effects:

[0043] A method for constructing a guaranteed power transmission system in an embodiment of the present application includes: constructing a three-layer guaranteed power grid defense model; setting constraints, the constraints include at least one or more of the following: basic guaranteed power source selection constraints, renewable energy power generation proportion constraints, and Kirchhoff's law constraints; using a column and constraint generation algorithm to decompose the three-layer guaranteed power grid defense model into a main problem and sub-problems; based on the constraints, solving the main problem and sub-problems until the convergence conditions are met, and outputting a guaranteed power grid construction model. A guaranteed power grid construction model is established based on the idea of ​​a two-stage robust optimization model. By setting constraints such as basic guaranteed power source selection constraints, renewable energy power generation proportion constraints, and Kirchhoff's law constraints, a guaranteed power grid construction method that considers the proportion of renewable energy power generation and line reinforcement is proposed, which provides a more reliable and flexible solution for the power system when a high proportion of renewable energy is connected.

[0044] A device for constructing a guaranteed power transmission system, an electronic device and a storage medium provided in an embodiment of the present application are provided with the above-mentioned method for constructing a guaranteed power transmission system. Since the method for constructing a guaranteed power transmission system has the above-mentioned technical effects, a device for constructing a guaranteed power transmission system, an electronic device and a storage medium provided with the method for constructing a guaranteed power transmission system should also have corresponding technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of a process for constructing a guaranteed power transmission system provided in an embodiment of the present application is shown;

[0046] Figure 2 A schematic diagram of power transmission line flow provided by an embodiment of the present application is shown;

[0047] Figure 3 A flow chart of a column and constraint generation algorithm provided in an embodiment of the present application is shown;

[0048] Figure 4 A node system diagram provided by an embodiment of the present application is shown;

[0049] Figure 5 A node system line connection diagram provided in an embodiment of the present application is shown;

[0050] Figure 6 A schematic diagram of a guaranteed power grid solution result provided in an embodiment of the present application is shown;

[0051] Figure 7 A schematic diagram of a device for constructing a guaranteed power transmission system provided in an embodiment of the present application is shown;

[0052] Figure 8 A schematic diagram of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0054] As mentioned above, new energy power generation mainly includes solar power generation and wind power generation. Solar power generation uses solar panels to directly convert sunlight into electrical energy. It has the advantages of wide distribution of resources, clean and pollution-free, renewable and inexhaustible. However, once encountering weather conditions such as heavy rain, haze, snow, sand and other weather conditions, the photovoltaic panels may not be able to receive sunlight, thus affecting the power generation efficiency. Wind power generation uses wind turbines to convert wind energy into electrical energy. It has the advantages of clean, renewable, short infrastructure cycle and flexible installed capacity. However, once encountering weather conditions such as strong winds and freezing rain, the wind turbine unit may be braked and cut out, causing the unit to shut down.

[0055] Building a guaranteed power grid is a typical measure to deal with extreme weather and improve the resilience of the power system. Reasonable planning of power grid resources, avoiding over-construction and waste, and building the smallest guaranteed power grid to reduce construction and maintenance costs can ensure the efficient operation of the guaranteed power grid and improve the utilization efficiency of power resources. However, there is currently no method suitable for building a guaranteed power grid when a high proportion of new energy is connected.

[0056] In order to solve at least one of the technical problems existing in the prior art or related technology, the present application provides a method, device, electronic device and storage medium for constructing a guaranteed power transmission system, the method comprising: constructing a three-layer guaranteed power grid defense model; setting constraints, the constraints at least including: one or more of the basic guaranteed power source selection constraints, the proportion of new energy power generation constraints and Kirchhoff's law constraints; using a column and constraint generation algorithm to decompose the three-layer guaranteed power grid defense model into a main problem and sub-problems; based on the constraints, solving the main problem and sub-problems until the convergence conditions are met, and outputting a guaranteed power grid construction model. A guaranteed power grid construction model is established based on the idea of ​​a two-stage robust optimization model. By setting constraints such as basic guaranteed power source selection constraints, new energy power generation proportion constraints and Kirchhoff's law constraints, a guaranteed power grid construction method that considers the proportion of new energy power generation and line reinforcement is proposed, which provides a more reliable and flexible solution for the power system when a high proportion of new energy is connected.

[0057] The following describes, with reference to the accompanying drawings, methods, devices and systems for constructing a guaranteed power generation and transmission system according to some embodiments provided by the present application.

[0058] See also Figures 1 to 8 The first aspect of the present application provides a method for constructing a guaranteed power transmission system, comprising:

[0059] S100: Build a three-layer bottom-line power grid defense model.

[0060] The guaranteed power grid construction model is established according to the idea of ​​the two-stage robust optimization model. The idea of ​​the two-stage robust optimization model is to decompose complex decision-making problems into two stages to deal with uncertain factors. It is particularly suitable for those situations where all parameters or conditions cannot be fully determined in the first stage of decision-making, and need to be adjusted and optimized according to new information or uncertain factors in the second stage. In the first stage, decision makers need to make some preliminary, long-term or strategic decisions when the specific values ​​of uncertain factors are unknown. These decisions will form a certain foundation or framework to provide a basis for the decision-making in the second stage; in the second stage, when the specific values ​​of uncertain factors are known or become clearer, decision makers need to make more specific, short-term or tactical decisions based on the decisions in the first stage according to this new information to optimize the overall goal.

[0061] In an exemplary embodiment, the steps of constructing a three-layer bottom-line grid defense model include:

[0062] S110: Build the first layer of defenders to select the backup grid and selectively reinforce the lines within the backup grid to minimize the load shedding of important loads.

[0063] The first layer of defenders establishes the objective function as shown below:

[0064]

[0065] In formula (1), u n ,u l is a binary decision variable for the guaranteed grid node n and line l. The value of 1 indicates that the node / line is selected as a node or line in the guaranteed grid, and the value of 0 indicates that the node or line does not belong to the guaranteed grid. l A binary decision variable indicating whether to reinforce the line. A value of 1 indicates that the line is reinforced, and a value of 0 indicates that it is not reinforced. N is the set of all nodes in the power grid. P n is the load of the node; P shed,n is the load shedding of the node; is the load shedding weight of node n. Different weights can be set according to the importance level of the node, so that the primary load is easier to remain in the guaranteed power grid.

[0066] Load shedding is an important concept in power systems. It refers to an operation in which part of the load is disconnected from the power grid in order to maintain the power balance and stability of the power system in the event of an accident.

[0067] Formula (1) indicates that the first-tier defender selects the bottom grid and reinforces it so that the weighted value of the shedding of important loads and the shedding of all loads is minimized when a disaster occurs.

[0068] S120: Construct a second layer of attackers to formulate disaster attack strategies for the backup power grid and reinforced lines selected by the first layer of defenders.

[0069] The second-level attacker establishes the target function as shown below:

[0070]

[0071] In formula (2), v l is the binary decision variable of the attacker on whether to attack line l, v l If it is equal to 0, it means that the attacker attacks line l and disconnects the line. l When 1 is equal to 1, it means that line l is not attacked; the other variables are the same as those in formula (1) and will not be repeated here.

[0072] Formula (2) indicates that the goal of the second layer is to generate the most severe attack situation and maximize the weighted value of load shedding.

[0073] S130: Construct a third-layer defender to optimize the flow of the second-layer attacker so as to minimize the expected value of the load shedding loss under the disaster attack strategy.

[0074] The third layer defender establishes the objective function as shown below:

[0075]

[0076] In formula (3), R is the set of power flow optimization variables, including {P shed,n ,P g ,P l ,θ n}, where P g represents the active output of generator g, P l represents the active power transmitted by line l, θ n represents the voltage phase angle of node n; the other variables are the same as those in formula (1) and will not be repeated here.

[0077] Formula (3) indicates that after the attacker successfully attacks, the system operator will optimize and reschedule the system according to the branch status of each interval in the recovery process to minimize the load shedding loss caused by the attack.

[0078] Based on equations (1), (2) and (3), the complete objective function of the three-layer guaranteed power grid defense model can be obtained as follows:

[0079]

[0080] The variables in formula (4) are the same as those in formula (1), formula (2), and formula (3), and will not be repeated here.

[0081] S200: Setting constraints, which at least include one or more of the following: basic power supply selection constraints, renewable energy power generation proportion constraints, and Kirchhoff's law constraints.

[0082] In the two-stage robust optimization model, setting constraints plays a vital role. These constraints ensure that the decisions in the first and second stages are still feasible under uncertain conditions. By limiting the value range of decision variables, decision plans that cannot be implemented in actual operations can be avoided.

[0083] In an exemplary implementation, the basic guaranteed power selection constraint is set as:

[0084]

[0085] In formula (5), S represents the set of conventional generator sets that are the backup power supply for the basic power supply of the transmission network, N is the set of all nodes in the power grid, and P n is the load of node n; P g represents the active output of generator g; u s A binary variable indicating whether the power source s is in operation; u n A binary variable indicating whether node n is selected into the guaranteed power grid.

[0086] Since the basic power supply of the guaranteed power grid has high requirements on the stability of power supply, and the new energy has uncontrollable volatility, the basic guaranteed power supply candidate set does not consider new energy for the time being, and is composed of 220KV, 500KV thermal power units, hydropower units and gas units. Formula (5) indicates that the guaranteed power supply capacity in the guaranteed power grid is greater than the load demand.

[0087] Furthermore, based on the selection of basic guaranteed power sources in the guaranteed power grid, black start unit constraints can also be set:

[0088]

[0089] In formula (6), B represents the set of generator sets with black start capability. Formula (6) indicates that the guaranteed power grid contains at least one black start unit. If black start is not considered, formula (6) can be ignored.

[0090] In an illustrative implementation, the renewable energy power generation ratio constraint is set as:

[0091]

[0092] In formula (7), S N is the set of renewable energy generating units, μ represents the proportion of renewable energy generating output in the power grid; P g represents the active output of generator g; u s A binary variable indicating whether power source s is operational.

[0093] In the power grid, gas turbines and diesel engines are controllable power sources and are responsible for controlling the frequency and voltage in the power grid. As uncontrollable power sources, the output of new energy generators is uncertain and cannot be used as the main power source. However, when the installed capacity of conventional units meets the load demand in the power grid, new energy units can be added to reduce the output of conventional units, thereby reducing the consumption of resources such as coal and reducing carbon emissions. The proportion of new energy power generation output in the power grid is described by formula (7).

[0094] In an exemplary embodiment, Kirchhoff's law constraints are set as:

[0095]

[0096] In formula (8), l represents the transmission line; u l Indicates whether the line is included in the guaranteed power grid, u l =1 means including, u l =0 means ignored; (z l +v l -z l v l ) represents the line reinforcement variable z l and the attack variable v l If z l =1, it means that line l is reinforced; if z l =0, it means that line l is not protected; if v l =0, it means line l is attacked; if v l =1, it means line l is not attacked; P l represents the active power transmitted by line l; θ o(l) represents the voltage phase angle of the source node of line l; θ d(l) represents the voltage phase angle of the target node of line l; L represents the set of lines in the system.

[0097] The linearized power flow model is used to establish the power flow constraints of the transmission line, such as Figure 2 As shown in the figure, a positive direction is pre-set for the line flow. For the transmission line l, o(l) is the source node of line l, and d(l) is the target node of line l. If the actual power flow is opposite to the positive direction, the flow is considered to be negative. Since the lines selected into the guaranteed grid are considered to be operating normally when selecting the guaranteed grid, and the lines not selected into the guaranteed grid are considered to be out of service, that is, there is no power flow, the guaranteed grid line selection variable has an impact on the DC flow. Specifically, each line l is related to the binary variable u l Therefore, Kirchhoff's law constraint can be expressed by the mixed integer nonlinear equation (8). l = 1, the line is reinforced, and the attack is ineffective on this line, because z l +v l -z l v l =z l =1; if a line is disconnected, the line must be under attack (v l =0) and unprotected (z l =0), so z l +v l -z l v l =0, then according to equation (8), the power on the line is 0. If the line is not attacked (v l =1), then P l x l =ul (θ o(l) -θ d(l) ).

[0098] Furthermore, set important load and branch retention constraints:

[0099]

[0100] In formula (9), N 1 Represents the important node set, which is set as the special load and the first-level important load set, N 1 The list of first-class important loads and second-class important loads can be adjusted according to specific circumstances. Formula (9) is used to ensure that important users that need to be protected are included in the scope of the guaranteed power grid.

[0101] Furthermore, set the connectivity constraints:

[0102]

[0103] -Mu l ≤F ij ≤Mu l ,ij∈L (11)

[0104] In formula (10), F ij Represents the virtual power of line ij; W j is an unrestricted real number; V sub is the set of source nodes, V\V sub Represents the set of nodes other than the source node; F js Indicates the virtual power of line js; u j Same as the above, represents the minimum grid node selection decision variable, a value of 1 indicates that node j is selected as a node in the minimum grid, and a value of 0 indicates that node j does not belong to the minimum grid.

[0105] In formula (11), L represents the set of lines in the system; u l Same as the above, it is the decision variable for selecting the minimum grid line l. The value of 1 indicates that the line l is selected as the line in the minimum grid, and the value of 0 indicates that the line l does not belong to the minimum grid. M is a sufficiently large real number.

[0106] The connectivity of the guaranteed power grid is ensured by constructing a virtual power flow. In the virtual network, a certain virtual power output power is set for the source nodes in the guaranteed power grid, and other nodes are set to a virtual load with a load value of 1. Formula (10) indicates that the virtual load can get the power supply of the virtual power source, that is, the guaranteed power grid is a connected power grid; Formula (11) indicates that if the line is disconnected, the virtual power will not be able to flow.

[0107] Furthermore, set the transmission power constraint:

[0108]

[0109] In formula (12), P l max is the upper limit of the transmission power of line l.

[0110] Furthermore, set the node angle constraint:

[0111]

[0112] In formula (13), θ max is the upper limit of the node phase angle, set to 2π.

[0113] Furthermore, set the node power balance constraint:

[0114]

[0115] In formula (14), the symbols are the same as above and will not be repeated here.

[0116] Furthermore, set the generator output constraints:

[0117]

[0118] In formula (15), P g max is the maximum output of generator g.

[0119] Furthermore, the protected lines need to be constrained within the guaranteed power grid:

[0120]

[0121] In formula (16), the symbols are the same as above and will not be repeated here.

[0122] Furthermore, set the decision variable constraints:

[0123]

[0124] In formula (17), the symbols are the same as above and will not be repeated here.

[0125] Furthermore, set the hardening resource constraints:

[0126]

[0127] In formula (18), R represents the limitation of reinforcement resources. Assuming that the line reinforcement in the guaranteed power grid has a budget constraint and the reinforcement cost is expressed by the number of reinforced lines, formula (18) indicates that the total cost of line reinforcement should be less than the reinforcement budget.

[0128] Furthermore, set the minimum number of grid lines:

[0129]

[0130] In formula (19), T represents the upper limit of the number of lines in the guaranteed power grid. As the minimum scale grid containing important nodes, the guaranteed power grid should have an upper limit on the number of lines.

[0131] Furthermore, set the attack resource constraints:

[0132]

[0133]

[0134] In formula (20), when any transmission line l is put into operation and operates normally, the line has a probability of failure, which is denoted as P l normal Under the influence of extreme weather, the failure probability of components will change, and it can be modeled by a new fragility curve, so there is a coupling relationship between the failure probability and extreme weather. Assume that the failure probability of the line under extreme weather becomes P l extreme , obviously there is P l extreme ≥P l normal By summing up the failure probabilities of all lines, we can obtain the mathematical expectation Λ of the probability that a component may fail under this extreme weather scenario.

[0135] In formula (21), v l is the binary decision variable of the attacker on whether to attack line l, v l If it is equal to 0, it means that the attacker attacks line l and disconnects the line. l A value equal to 1 indicates that line l is not attacked. This is the total number of disconnections caused by the attack. Since extreme weather has limited ability to cause damage, the mathematical expectation of the failure probability is selected as the upper limit of the attack budget, that is, the total number of disconnections caused by the attack does not exceed Λ.

[0136] Furthermore, set the line status constraints:

[0137] q l =z l +v l -z l v l (twenty two)

[0138] Formula (22) is the auxiliary variable for judging the line status, where q l Indicates the state of line l, q l If it is equal to 1, it means that line l is operating normally, and q lEqual to 0 means line l is disconnected. The line is disconnected only when the line is attacked and not reinforced; it operates normally when the line is not attacked or reinforced.

[0139] S300: The three-layer guaranteed power grid defense model is decomposed into main problems and sub-problems using the column and constraint generation algorithm.

[0140] The column-and-constraint generation (C&CG) algorithm is used to solve the two-stage planning problem established in this application. The C&CG algorithm decomposes the original model into main and sub-problems for alternating iterative solutions until the upper and lower bounds meet the solution accuracy requirements during the iteration process, and the optimal solution of the original problem is obtained.

[0141] In an illustrative embodiment, the steps of using a column and constraint generation algorithm to decompose the three-layer guaranteed power grid defense model into a main problem and sub-problems include: combining the second-layer attacker and the third-layer defender as a sub-problem, the sub-problem is used to solve the disaster attack strategy given by the combination of the second-layer attacker and the third-layer defender, and returning the disaster attack strategy to the main problem in each iteration; taking the first-layer defender as the main problem, the main problem is used to solve the guaranteed power grid selection plan and line reinforcement plan given by the first-layer defender based on a set of attack plans composed of disaster attack strategies.

[0142] The three-layer guaranteed power grid defense model is divided into two layers, upper and lower. Let the decision variables related to the upper planning layer be y, and the decision variables related to the power flow optimization of the lower operation layer be x. The three-layer guaranteed power grid defense model can be written in the following matrix form:

[0143]

[0144] In formula (23), A, G 1 , G 2 、E 1 、E 2 are coefficient matrices respectively; b is the value vector; d is the right-hand side vector of the upper constraint, h 1 With h 2 are the right-hand side vectors of the lower-level inequality and equality constraints respectively.

[0145] In the three-layer guaranteed power grid defense model, when the upper layer gives a guaranteed power grid construction plan considering line reinforcement, the lower operation layer will solve the optimal power flow operation plan under the worst case, that is, The operation plan should meet the operation constraints.

[0146] It can be seen that for every guaranteed grid construction scheme considering line reinforcement given by the upper layer, the lower operation layer can always solve the worst attack situation x and load shedding therefore, In fact, it is a function of plan y. The attack plan solved by the lower layer is passed to the upper layer, which can then solve the bottom-line power grid construction plan and line reinforcement plan.

[0147] According to the C&CG algorithm, the robustness model shown in formula (23) can be decomposed into the main problem shown in formula (24) and the sub-problem shown in formula (25). The sub-problem solves the disaster attack strategy after the given minimum grid construction and line reinforcement plan, and returns the attack strategy to the main problem in each iteration; the main problem solves the optimal minimum grid selection plan and line protection plan based on a set of attack plans composed of a series of attack strategies.

[0148]

[0149] According to the C&CG algorithm, solve equation (25). The objective function of the algorithm in the sub-problem is When bounded, the corresponding optimal solution (u * ,x * ), identify the corresponding u when Q(y) is unbounded * .

[0150] S400: Based on the constraints, solve the main problem and sub-problems until the convergence conditions are met, and output the minimum power grid construction model.

[0151] like Figure 3 As shown in Figure 2, the optimality tolerance in the C&CG algorithm is ε, and the specific steps are as follows:

[0152] S410: Initialize the lower bound, upper bound, number of iterations and attack plan set.

[0153] Set the lower bound LB = -∞, the upper bound UB = ∞, the number of iterations k = 0, and the attack plan set

[0154] S420: Based on the constraints, solve the main problem to obtain the first solution value and the bottom-line grid selection plan and line reinforcement plan given by the first-layer defender; use the first solution value to update the lower bound.

[0155] Based on the constraint conditions (5)-(22), where (8)-(9) and (12)-(22) are necessary constraint conditions, and (5)-(7) and (10)-(11) are optional constraint conditions, solve MP in (24) and get the first solution value MPobj: and a guaranteed grid planning scheme that takes line protection into account Then use MPobj to update the value of the lower bound LB

[0156] S430: Based on the constraints, solve the subproblem to obtain a second solution value and a disaster attack strategy; use the second solution value to update the upper bound, add the disaster attack strategy to the attack plan set, and update the constraints.

[0157] Based on the constraint conditions (5)-(22), where (8)-(9) and (12)-(22) are necessary constraints, (5)-(7) and (10)-(11) are optional constraints, solve SP in (25) to obtain the second solution value SPobj and disaster attack strategy Then update the upper bound value Will Add to middle.

[0158] if That is, SPobj is bounded, and a new decision variable x is added to MP k+1 , update V = V ∪ {k + 1}, and add the following constraints in MP:

[0159]

[0160] If SPobj is unbounded, add a new decision variable x to MP k+1 , and add the following constraints in MP:

[0161]

[0162] S440: Based on the updated constraints, iterate repeatedly to solve the main problem and sub-problems until the convergence condition is met, and output the minimum grid selection plan and line reinforcement plan given by the first-layer defender obtained by solving the main problem after the convergence condition is met as a minimum grid construction model.

[0163] If the convergence condition (UB-LB) / LB≤ε is met, stop; otherwise, set k=k+1, return to step S420 and repeat the iteration until the convergence condition is met, and output the minimum grid selection plan and line reinforcement plan given by the first-layer defender as a minimum grid construction model.

[0164] Example:

[0165] like Figure 4As shown in the figure, the IEEE RTS-96 high-voltage distribution network test system is used as an example to verify the effectiveness and feasibility of the proposed model and method. The distribution network consists of 24 nodes, 38 lines, 32 power sources and 17 loads. A set of important nodes is given in the system, including eight nodes 1, 2, 7, 10, 19, 20, 21, and 24. Excluding the generator nodes and nodes with load 0, and considering the topological structure of the system, four loads 9, 10, 19, and 20 are selected as important loads. Figure 4 The proportion of important loads is 16.67%, which is close to the proportion of primary loads in reality. In order to more intuitively reflect the structure of the guaranteed power grid, Figure 4 Based on this, the specific values ​​of transformer, load and generator output are omitted, and only nodes and lines are retained to make a node-line connection diagram of the 24-node system as shown in the figure. Figure 5 shown.

[0166] This example is solved using the Cplex 12.10.0.0 solver on the MATLAB R2023a platform. The solution accuracy MIPGap is set to 0.01%. The computer configuration used is: CPU i7-13620H CPU@2.40GHz, memory 16GB, and operating system Windows10 64bit.

[0167] The upper limit T of the guaranteed power grid line, the line reinforcement budget R, and the attack budget Λ can all be adjusted according to the actual situation of the local power grid and the level of extreme weather. Ignore the constraint on the proportion of new energy, that is, μ is an arbitrary value. For load weight Since the bottom-line power grid aims to improve the power supply security of urban core areas and important users, in the early stage of modeling, when selecting the bottom-line power grid and reinforced lines, the objective function only considers the minimum load shedding of important loads, that is, Where N 1 However, in actual programming, it is found that if only the shedding of five important loads is considered, the shedding of important loads can be easily reduced to 0, even if the attack budget is very high.

[0168] The parameters of Case 1 are set as follows: line reinforcement budget R = 2, extreme weather attack budget Λ = 4, and the upper limit of the guaranteed power grid line T = 17. The structure of the guaranteed power grid is obtained as follows: Figure 6 As shown, the line reinforcement and the most severe attack scenarios are shown in Table 1.

[0169] Table 1 Solution results

[0170]

[0171] The guaranteed power grid aims to improve the power supply security of the core areas of the city and important users. In this example, the important load shedding is 105.01MW, and the load shedding ratio is 15.46%. There are five generators in the guaranteed power grid with a total installed capacity of 1444.3MW, which can meet the load demand in the guaranteed power grid. The generators at nodes 7, 15, 18, and 21 that are not selected into the guaranteed power grid are all generating electricity independently to ensure the load demand of their own nodes, so as to minimize the total load shedding and meet the requirements of the objective function.

[0172] Two lines, 10-12 and 16-19, were selected for line reinforcement. Line 16-19 connects the generator and the important node 19, and line 10-12 is also a key line connecting the important node 10. Therefore, when reinforcement resources are limited, selecting key lines connecting important loads can better minimize load shedding.

[0173] like Figure 7 As shown, the second embodiment of the present application provides a device for constructing a guaranteed power transmission system, including:

[0174] Building module 71, for building a three-layer bottom-line power grid defense model;

[0175] The constraint module 72 is used to set constraint conditions, which at least include: one or more of the basic guaranteed power source selection constraint, the renewable energy power generation proportion constraint and the Kirchhoff's law constraint;

[0176] A disassembly module 73, for disassembling the three-layer bottom-line power grid defense model into a main problem and sub-problems by using a column and constraint generation algorithm;

[0177] The output module 74 is used to solve the main problem and sub-problems based on the constraint conditions until the convergence conditions are met, and output the minimum power grid construction model.

[0178] In some embodiments of the present application, the steps of constructing module 71 for constructing a three-layer bottom-line power grid defense model include:

[0179] Build the first layer of defenders to select the backup grid and selectively reinforce the lines within the backup grid to minimize the shedding of important loads;

[0180] Construct a second layer of attackers to formulate disaster attack strategies for the backup power grid and reinforced lines selected by the first layer of defenders;

[0181] The third layer of defenders is constructed to optimize the power flow of the second layer of attackers, so as to minimize the expected value of load shedding loss under the disaster attack strategy.

[0182] In some embodiments of the present application, the steps of the disassembly module 73 for disassembling the three-layer bottom-line grid defense model into a main problem and sub-problems using a column and constraint generation algorithm include:

[0183] The second-layer attacker and the third-layer defender are combined as a sub-problem. The sub-problem is used to solve the disaster attack strategy given by the combination of the second-layer attacker and the third-layer defender, and the disaster attack strategy is returned to the main problem in each iteration;

[0184] The first-layer defender is taken as the main problem. The main problem is used to solve the bottom-line power grid selection plan and line reinforcement plan given by the first-layer defender based on the set of attack plans composed of disaster attack strategies.

[0185] In some embodiments of the present application, the output module 74 is used to solve the main problem and the sub-problems based on the constraint conditions until the convergence conditions are met, and the steps of outputting the guaranteed power grid construction model include:

[0186] Initialize the lower bound, upper bound, number of iterations, and attack plan set;

[0187] Based on the constraints, solve the main problem, obtain the first solution value and the bottom-line grid selection plan and line reinforcement plan given by the first-layer defender; use the first solution value to update the lower bound;

[0188] Based on the constraints, solve the subproblem to obtain the second solution value and the disaster attack strategy; use the second solution value to update the upper bound, add the disaster attack strategy to the attack plan set, and update the constraints;

[0189] Based on the updated constraints, the iteration is repeated to solve the main problem and sub-problems until the convergence conditions are met. The minimum grid selection plan and line reinforcement plan given by the first-layer defender obtained by solving the main problem after the convergence conditions are met are output as a minimum grid construction model.

[0190] In some embodiments of the present application, the constraint module 72 is used to select the basic guaranteed power supply constraint as follows:

[0191]

[0192] Among them, S represents the set of conventional generator sets that are the basic power supply of the transmission network, N is the set of all nodes in the power grid, and P n is the load of node n.

[0193] In some embodiments of the present application, the constraint module 72 is used to constrain the proportion of renewable energy power generation as follows:

[0194]

[0195] Among them, S Nis the collection of renewable energy generating units, and μ represents the proportion of renewable energy power generation output in the power grid.

[0196] In some embodiments of the present application, the constraint module 72 is used for Kirchhoff's law constraints:

[0197]

[0198] Where, l represents the transmission line; u l Indicates whether the line is included in the guaranteed power grid, u l =1 means including, u l =0 means ignored; (z l +v l -z l v l ) represents the line reinforcement variable z l and the attack variable v l If z l =1, it means that line l is reinforced; if z l =0, it means that line l is not protected; if v l =0, it means line l is attacked; if v l =1, it means line l is not attacked; P l represents the active power transmitted by line l; θ o(l) represents the voltage phase angle of the source node of line l; θ d(l) represents the voltage phase angle of the target node of line l; L represents the set of lines in the system.

[0199] like Figure 8 As shown, the third aspect of the present application provides an electronic device 700, including:

[0200] The memory 710 and the processor 720, the memory 710 is used to store the computer program and transmit the program code to the processor 720. In other words, the processor 720 can call and run the computer program from the memory 710 to implement the method in the embodiment of the present application.

[0201] For example, the processor 720 may be configured to execute the above method embodiments according to instructions in the computer program.

[0202] In some embodiments of the present application, the processor 720 may include but is not limited to:

[0203] General-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc.

[0204] In some embodiments of the present application, the memory 710 includes but is not limited to:

[0205] Volatile memory and / or non-volatile memory. Among them, the non-volatile memory can be read-only memory (ROM), programmable ROM (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM).

[0206] In some embodiments of the present application, the computer program may be divided into one or more modules, which are stored in the memory 710 and executed by the processor 720 to complete the method provided by the present application. The one or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the controller.

[0207] The electronic device 700 may further include:

[0208] The transceiver 730 may be connected to the processor 720 or the memory 710 .

[0209] The processor 720 may control the transceiver 730 to communicate with other devices, specifically, to send data or data to other devices, or to receive data or data sent by other devices. The transceiver 730 may include a transmitter and a receiver. The transceiver 730 may further include an antenna, and the number of antennas may be one or more.

[0210] It should be understood that the various components in the electronic device are connected via a bus system, wherein the bus system includes not only a data bus but also a power bus, a control bus and a status signal bus.

[0211] The fourth aspect of the present application also provides a computer storage medium on which a computer program is stored, and when the computer program is executed by a computer, the computer can perform the method of the above method embodiment. In other words, an embodiment provided by the present application also provides a computer program product containing instructions, and when the instructions are executed by a computer, the computer can perform the method of the above method embodiment.

[0212] When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instruction is loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instruction can be stored in a computer-readable storage medium, or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instruction can be transmitted from a website site, a computer, a server, or a data center by wired (e.g., coaxial cable, optical fiber, digital client line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server, or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, a data center, etc. that includes one or more available media integration. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a digital video disc (Digital Video Disc, DVD)), or a semiconductor medium (e.g., a solid-state drive (Solid State Disk, SSD)), etc.

[0213] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments applied for herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0214] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the module is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0215] It should be noted that the terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0216] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "exemplary embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0217] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for constructing a guaranteed power transmission system, characterized in that: include: Construct a three-layer bottom-line power grid defense model; Setting constraints, wherein the constraints include at least one or more of: basic guaranteed power source selection constraints, renewable energy power generation proportion constraints, and Kirchhoff's law constraints; The three-layer guaranteed power grid defense model is decomposed into main problems and sub-problems by using a column and constraint generation algorithm; Based on the constraint conditions, the main problem and the sub-problems are solved until convergence conditions are met, and a guaranteed power grid construction model is output.

2. A method for constructing a guaranteed power transmission system according to claim 1, characterized in that: The steps of constructing the three-layer bottom-line power grid defense model include: Constructing the first layer of defenders to select a backup grid and selectively reinforce the lines within the backup grid to minimize the shedding of important loads; Construct a second layer of attackers to formulate disaster attack strategies for the backup power grid and reinforced lines selected by the first layer of defenders; A third layer of defenders is constructed to optimize the flow of the second layer of attackers so as to minimize the expected value of load shedding loss under the disaster attack strategy.

3. A method for constructing a guaranteed power transmission system according to claim 2, characterized in that: The step of using the column and constraint generation algorithm to decompose the three-layer guaranteed power grid defense model into a main problem and sub-problems includes: The second-layer attacker and the third-layer defender are combined as a sub-problem, the sub-problem is used to solve the disaster attack strategy given by the combination of the second-layer attacker and the third-layer defender, and the disaster attack strategy is returned to the main problem in each iteration; The first-layer defender is taken as the main problem, and the main problem is used to solve the bottom-line power grid selection plan and line reinforcement plan given by the first-layer defender based on the set of attack plans composed of the disaster attack strategy.

4. A method for constructing a guaranteed power transmission system according to claim 3, characterized in that: The step of solving the main problem and the sub-problems based on the constraint conditions until convergence conditions are met and outputting a guaranteed power grid construction model comprises: Initialize the lower bound, upper bound, number of iterations, and attack plan set; Based on the constraint conditions, the main problem is solved to obtain a first solution value and a bottom-line grid selection scheme and a line reinforcement scheme provided by the first-layer defender; and the lower bound is updated with the first solution value; Based on the constraint condition, solve the subproblem to obtain a second solution value and the disaster attack strategy; update the upper bound with the second solution value, add the disaster attack strategy to the attack plan set, and update the constraint condition; Based on the updated constraints, the iteration is repeated to solve the main problem and the sub-problems until the convergence condition is met. The bottom-line grid selection plan and line reinforcement plan given by the first-layer defender obtained by solving the main problem after the convergence condition is met are output as a bottom-line grid construction model.

5. A method for constructing a guaranteed power transmission system according to claim 1, characterized in that: The basic guaranteed power selection constraints are: Among them, S represents the set of conventional generator sets that are the basic power supply of the transmission network, N is the set of all nodes in the power grid, and P n is the load of node n; P g represents the active output of generator g; u s A binary variable indicating whether the power source s is in operation; u n A binary variable indicating whether node n is selected into the guaranteed power grid.

6. A method for constructing a guaranteed power transmission system according to claim 1, characterized in that: The constraint on the proportion of renewable energy power generation is: Among them, S N is the set of renewable energy generating units, μ represents the proportion of renewable energy generating output in the power grid; P g represents the active output of generator g; u s A binary variable indicating whether power source s is operational.

7. A method for constructing a guaranteed power transmission system according to claim 1, characterized in that: Kirchhoff's law constraints are: Where, l represents the transmission line; u l Indicates whether the line is included in the guaranteed power grid, u l =1 means including, u l =0 means ignored; (z l +v l -z l v l ) represents the line reinforcement variable z l and the attack variable v l If z l =1, it means that line l is reinforced; if z l =0, it means that line l is not protected; if v l =0, it means line l is attacked; if v l =1, it means line l is not attacked; P l represents the active power transmitted by line l; θ o(l) represents the voltage phase angle of the source node of line l; θ d(l) represents the voltage phase angle of the target node of line l; L represents the set of lines in the system.

8. A device for constructing a guaranteed power transmission system, characterized in that: include: Building modules for constructing a three-layer bottom-line grid defense model; A constraint module, used to set constraint conditions, wherein the constraint conditions include at least one or more of: a basic guaranteed power source selection constraint, a new energy power generation proportion constraint, and a Kirchhoff's law constraint; A disassembly module, for disassembling the three-layer bottom-line power grid defense model into a main problem and sub-problems by using a column and constraint generation algorithm; The output module is used to solve the main problem and the sub-problems based on the constraint conditions until the convergence conditions are met, and output a guaranteed power grid construction model.

9. An electronic device, characterized in that: include: A processor and a memory, the memory being used to store a computer program, and the processor being used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store a computer program, wherein the computer program enables a computer to execute the method according to any one of claims 1 to 7.

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