Unit restoration method and system considering bidirectional coupling characteristics of power transmission network and gas transmission network

Abstract

This invention provides a unit restoration method and system that considers the bidirectional coupling characteristics of power transmission networks and gas transmission networks, belonging to the field of power system safety and stability technology. The method involves determining the objective function for restoring the system's power generation capacity; constructing restoration constraints for the power transmission network; constructing constraints for the gas transmission network; constructing coupling constraints for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources; combining the objective function with the constructed constraints of the power transmission network, gas transmission network, and the three types of coupled equipment, establishing a mixed-integer linear programming model; solving the mixed-integer linear programming model to obtain the restoration strategy for the power transmission network at various time periods. This invention addresses the highly coupled power transmission and gas transmission networks by modeling the unit restoration problem considering the bidirectional coupling effect of the two networks as a mixed-integer linear programming model, solving the model to obtain the unit restoration strategy, and rapidly restoring the system's power generation capacity.

Description

Technical Field

[0001] This invention relates to the field of power system safety and stability technology, specifically to a unit restoration method and system that takes into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network. Background Technology

[0002] Currently, the coupling between the power grid and the natural gas grid is becoming increasingly close. As a high-quality transitional power source, the proportion of gas turbine units continues to increase; for environmental and economic reasons, electrically driven compressors and gas sources are widely used in natural gas systems. This close connection between the two grids can lead to cascading failures and affect system recovery. In the initial stages of system recovery, the operation of the gas transmission network will affect the startup of gas turbine units, and the restoration of key electrically driven facilities in the gas transmission network will also affect the operation of the gas transmission network. Therefore, the bidirectional coupling characteristics of the two grids must be fully considered when formulating unit recovery strategies to ensure the effectiveness and optimality of the strategies.

[0003] The unit recovery phase requires decisions on the startup or recovery sequence of units and power paths. Currently, there is extensive research on traditional unit recovery optimization decisions. With the increasingly close coupling between the power grid and the natural gas network, some scholars have begun preliminary research on the coordinated recovery of the power grid and natural gas network. For example, research has been conducted on the resilience of integrated power-gas systems under extreme events, showing that coupled operation of the power grid and gas network has stronger recovery capabilities; from the perspective of post-disaster maintenance personnel scheduling, a joint scheduling method for maintenance personnel in the power-gas coupled system has been proposed to achieve coordinated optimization of the equipment repair sequence in both systems; for load recovery of the distribution network and the natural gas network, considering the independence of their operation, a distributed load recovery method for integrated power-gas energy systems has been proposed; comprehensively considering the interdependence of electricity, water, and gas in the distribution network system, and aiming to maximize the energy recovery of key users, a mixed integer second-order cone model for energy distribution network system fault recovery has been established; and for urban integrated energy systems, a key load recovery method based on the synergy of multiple energy flows (electricity, gas, and heat) has been proposed. Currently, research on the coordinated recovery of the power grid and the natural gas network rarely focuses on the unit recovery phase after a major power outage. However, after a major power outage, the restoration of power supply to key electric drive facilities in the gas transmission network affects the operation of the gas transmission network, which in turn affects the restoration of gas turbine units. Summary of the Invention

[0004] The purpose of this invention is to provide a unit recovery method and system that takes into account the bidirectional coupling characteristics of the transmission and gas transmission networks, for highly coupled power grids and gas transmission networks, and models the unit recovery problem as a mixed integer linear programming model, solves the model to obtain the unit recovery strategy, and quickly restores the system's power generation capacity, thereby solving at least one of the technical problems existing in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] On one hand, the present invention provides a unit restoration method that takes into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network, comprising:

[0007] Determine the objective function for restoring the system's power generation capacity;

[0008] Construct power transmission network restoration constraints;

[0009] Constructing constraints for the gas transmission network;

[0010] Coupling constraints are constructed for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources.

[0011] Based on the objective function, and considering the constructed constraints of power transmission network recovery, gas transmission network, and coupling constraints of three types of coupled equipment—gas turbine units, electric-driven compressor stations, and electric-driven gas sources—a mixed-integer linear programming model is established.

[0012] Solve the mixed-integer linear programming model to obtain the recovery strategy for the power transmission network in each time period.

[0013] Preferably, the objective function is set as maximizing the power generation capacity of the transmission network, mathematically expressed as:

[0014]

[0015] In the formula: ut g,i are 0-1 integer decision variables representing the state of the unit; they are 1 if the unit has recovered, and 0 otherwise; C i Unit capacity; Pcrk i is the unit starting power; S NBS This refers to the set of non-black start units in the system.

[0016] Preferably, the power grid restoration constraints are constructed, including:

[0017]

[0018]

[0019] res(x)=ceil(x)-x (4)

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[0033] In the formula: ut b,i, ut l,ij, and ut ld,ij are 0-1 integer decision variables, representing the state of the bus node, path, and load, respectively. If the state has recovered, the variable is 1; otherwise, it is 0. ut bg,i and ut b-ld,i represent the state of the bus node connected to the non-black start unit and load, respectively. tCH i and tCL i represent the maximum and minimum critical times that the unit must meet to start up, respectively. Pt ld,j represents the power of the load. Qt sys, Qmin g,i, Qcrk g,i, and Q ld,j These represent the system reactive power, the unit's minimum reactive power output, the unit's starting reactive power, and the load reactive power, respectively; B l,ij V represents the susceptance of the line; T represents the voltage level of the line. CL Indicates the latest recovery time for critical loads; S t S is the set of recovery periods up to time t; T S is the set of all recovery periods; G S BS S NBS S represents the set of all units, black-start units, and non-black-start units within the system, respectively; T / T represents the set of recovery periods excluding time period T; S L S B S L-B,i S B-BS S B / S B-BS Let S represent the path, bus node, path connected to bus node i, bus node connected to the black starter unit, and set of bus nodes excluding those connected to the black starter unit in the system; LD S CL These represent the sets of loads and critical loads in the system, respectively.

[0034] Preferably, gas transmission network constraints are constructed, including pipeline dynamic constraints:

[0035]

[0036]

[0037]

[0038] In the formula: ρtn,i is the node density of natural gas; Πtn,i is the node pressure of natural gas; Mtin,ij and Mtout,ij represent the mass flow rates of natural gas flowing into and out of the pipeline, respectively; Li ij Δt is the differential space step size, i.e., the pipe length; Δt is the differential time step size, i.e., the recovery time period length; S N S represents the set of gas transmission nodes; P The collection of gas pipelines in the system; S T It is the set of all recovery periods;

[0039] Preferably, the construction of gas transmission network constraints also includes pipeline boundary constraints and initial constraints:

[0040] Based on the initial and boundary conditions given by the gas transmission pipeline network, the dynamic distribution of gas pressure and flow rate can be obtained by solving equations (18)-(20); the initial constraint refers to the previous steady-state value of the pipeline network; the boundary constraint refers to the boundary conditions at the end of the pipeline, including the flow balance constraint of the node, the gas pressure boundary, the flow rate boundary and the gas supply limit of the gas source.

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[0052] In the formula: ut c,ij and ut s,i are 0-1 integer decision variables, representing the power supply status of the electric-driven compressor station and the electric-driven gas source, respectively. If the power supply has been restored, the value is 1; otherwise, the value is 0. Π0nc,ij, Π0c,ij, Π0ns,i and Π0s,i represent the outlet pressure setpoints of the non-electric-driven compressor station, the electric-driven compressor station, the non-electric-driven gas source and the electric-driven gas source, respectively. Πt n-ns,i and Πtn-s,i represent the node gas pressures of the non-electric-driven gas source and the electric-driven gas source, respectively. M t in-ns,i, M t in-s,i and M tout-l,i represent the pipeline natural gas flow rates of the non-electric-driven gas source, the electric-driven gas source and the natural gas load, respectively. M ns,i , M s,i These represent the upper and lower limits of the gas supply capacity of the non-electrically driven gas source and the electrically driven gas source, respectively; M l,i S represents the natural gas load; I S represents the set of pipe junctions; i→j S j→k Let S represent the sets of upstream nodes of natural gas inflow node j and downstream nodes of natural gas outflow node j, respectively; C S NC S S S NS S GL These represent the collections of electrically driven compressor stations, non-electrically driven compressor stations, electrically driven gas sources, non-electrically driven gas sources, and natural gas loads, respectively.

[0053] Preferably, constructing coupling device constraints includes:

[0054] Gas turbine unit constraints:

[0055]

[0056]

[0057]

[0058]

[0059] In the formula: ut f,i is a 0-1 integer decision variable, representing whether the gas turbine unit has gas supply conditions; if it does, it takes the value 1, otherwise it takes the value 0; Pt g,i is the unit output; M tf,i represents the natural gas consumption of the gas turbine unit; k i Indicates the energy conversion parameters of the unit; The average gas pressure during the period when the gas supply nodes of the gas turbine unit are connected; Π f,iThis refers to the minimum gas pressure requirement for the gas supply node of the gas turbine unit; S F This represents the collection of gas turbine units in the system;

[0060] Electric drive compressor station constraints:

[0061]

[0062]

[0063] In the formula: ut ld-c,ij represents the state of the load supplying power to the electric compressor station;

[0064] Electric drive air source constraints:

[0065]

[0066]

[0067] In the formula: ut ld-s,i represents the state of the load supplying power to the electric drive air source.

[0068] Secondly, the present invention provides a unit recovery system that takes into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network, comprising:

[0069] The determination module is used to determine the objective function for restoring the system's power generation capacity.

[0070] The first construction module is used to construct power grid recovery constraints;

[0071] The second building module is used to construct gas transmission network constraints;

[0072] The third construction module is used to construct coupling constraints for three types of coupled devices: gas turbine units, electric-driven compressor stations, and electric-driven gas sources.

[0073] The fourth construction module is used to combine the objective function and establish a mixed-integer linear programming model based on the constructed transmission network recovery constraints, gas transmission network constraints, and coupling constraints of three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources.

[0074] The calculation module is used to solve the mixed-integer linear programming model to obtain the recovery strategy of the power transmission network for each time period.

[0075] Thirdly, the present invention provides a non-transitory computer-readable storage medium for storing computer instructions, which, when executed by a processor, implement the unit recovery method described above, taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network.

[0076] Fourthly, the present invention provides a computer program product, including a computer program that, when run on one or more processors, is used to implement the unit recovery method as described above, taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network.

[0077] Fifthly, the present invention provides an electronic device, comprising: a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to cause the electronic device to execute instructions for implementing the unit restoration method taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network as described above.

[0078] The beneficial effects of this invention are as follows: For highly coupled power transmission networks and gas transmission networks, the unit recovery problem considering the bidirectional coupling effect of the two networks is modeled as a mixed integer linear programming model. Solving the model yields the unit recovery strategy, which can quickly restore the system's power generation capacity.

[0079] The advantages of additional aspects of the invention will be set forth more clearly in the following description or will be learned by practice of the invention. Attached Figure Description

[0080] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0081] Figure 1 This is a structural diagram of the application test system for the unit recovery optimization decision-making method that takes into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network, as described in an embodiment of the present invention. Detailed Implementation

[0082] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0083] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0084] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0085] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0086] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0087] To facilitate understanding of the present invention, the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0088] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0089] Example 1

[0090] In this embodiment 1, the unit recovery problem considering the bidirectional coupling effect of the power transmission network and the gas transmission network is modeled as a mixed integer linear programming model. The model is solved to obtain the recovery schemes for the unit, the route, and the electric drive facilities of the gas transmission network.

[0091] First, this embodiment 1 provides a unit recovery system that considers the bidirectional coupling characteristics of the power transmission network and the gas transmission network. The system includes: a determination module for determining the objective function for restoring the power generation capacity of the system; a first construction module for constructing power transmission network recovery constraints; a second construction module for constructing gas transmission network constraints; a third construction module for constructing coupling constraints for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources; a fourth construction module for combining the objective function with the constructed power transmission network recovery constraints, gas transmission network constraints, and coupling constraints of the three types of coupled equipment to establish a mixed-integer linear programming model; and a calculation module for solving the mixed-integer linear programming model to obtain the recovery strategy of the power transmission network for each time period.

[0092] Secondly, in this embodiment 1, the above-described system is used to implement a unit recovery method that takes into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network, including:

[0093] The objective function for restoring the system's power generation capacity is determined using the determination module; the first construction module is used to construct the transmission network restoration constraints; the second construction module is used to construct the gas transmission network constraints; the third construction module is used to construct coupling constraints for the three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources; the fourth construction module, combined with the objective function, establishes a mixed-integer linear programming model based on the constructed transmission network restoration constraints, gas transmission network constraints, and coupling constraints of the three types of coupled equipment; finally, the calculation module is used to solve the mixed-integer linear programming model to obtain the restoration strategies for the transmission network at various time periods.

[0094] The objective function is set as maximizing the power generation capacity of the transmission network, mathematically expressed as:

[0095]

[0096] In the formula: ut g,i are 0-1 integer decision variables representing the state of the unit; they are 1 if the unit has recovered, and 0 otherwise; C i Unit capacity; Pcrk i is the unit starting power; S NBS This refers to the set of non-black start units in the system.

[0097] Constructing power transmission network restoration constraints includes:

[0098]

[0099]

[0100] res(x)=ceil(x)-x (4)

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[0114] In the formula: ut b,i, ut l,ij, and ut ld,ij are 0-1 integer decision variables, representing the state of the bus node, path, and load, respectively. If the state has recovered, the variable is 1; otherwise, it is 0. ut bg,i and ut b-ld,i represent the state of the bus node connected to the non-black start unit and load, respectively. tCH i and tCL i represent the maximum and minimum critical times that the unit must meet to start up, respectively. Pt ld,j represents the power of the load. Qt sys, Qmin g,i, Qcrk g,i, and Q ld,j These represent the system reactive power, the unit's minimum reactive power output, the unit's starting reactive power, and the load reactive power, respectively; B l,ij V represents the susceptance of the line; T represents the voltage level of the line. CL Indicates the latest recovery time for critical loads; S t S is the set of recovery periods up to time t; T S is the set of all recovery periods; G S BS S NBS S represents the set of all units, black-start units, and non-black-start units within the system, respectively; T / T represents the set of recovery periods excluding time period T; S L S B S L-B,i S B-BS SB / S B-BS These represent the paths, bus nodes, paths connected to bus node i, bus nodes connected to the black starter unit, and the set of bus nodes excluding those connected to the black starter unit, respectively; SLD and SCL represent the sets of loads and critical loads in the system, respectively.

[0115] Among them, constraint (2) is the linearized unit output function; constraints (3) and (4) are functions introduced by discretization and rounding, which provide constant parameters for the constraint construction of the optimization model; (5) is the maximum and minimum critical time constraint that the unit startup must meet; constraints (6) and (7) are the recovery logic constraints for non-black start unit startup; constraints (8)-(11) are the path recovery logic constraints; constraints (12) and (13) indicate that the system should have sufficient reactive power balancing capacity to cope with the inductive reactive power generated by the unloaded line and transformer; constraint (14) is the system active power constraint; constraints (15) and (16) are the load recovery logic constraints; constraint (17) indicates that the critical load must be restored before the set time.

[0116] Constructing gas transmission network constraints, including pipeline dynamic constraints:

[0117]

[0118]

[0119]

[0120] In the formula: ρtn,i is the node density of natural gas; Πtn,i is the node pressure of natural gas; Mtin,ij and Mtout,ij represent the mass flow rates of natural gas flowing into and out of the pipeline, respectively; Li ij Δt is the differential space step size, i.e., the pipe length; Δt is the differential time step size, i.e., the recovery time period length; S N S represents the set of gas transmission nodes; P The collection of gas pipelines in the system; S T is the set consisting of all recovery periods. Among them, constraints (18)-(20) are a set of linear algebraic equations describing the dynamic distribution law of natural gas energy flow, which respectively represent the continuity equation, momentum equation and gas state equation after differential discretization.

[0121] Constructing gas transmission network constraints also includes pipeline boundary constraints and initial constraints:

[0122] Based on the initial and boundary conditions given by the gas transmission pipeline network, the dynamic distribution of gas pressure and flow rate can be obtained by solving equations (18)-(20); the initial constraint refers to the previous steady-state value of the pipeline network; the boundary constraint refers to the boundary conditions at the end of the pipeline, including the flow balance constraint of the node, the gas pressure boundary, the flow rate boundary and the gas supply limit of the gas source.

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[0134] In the formula: ut c,ij and ut s,i are 0-1 integer decision variables, representing the power supply status of the electric-driven compressor station and the electric-driven gas source, respectively. If the power supply has been restored, the value is 1; otherwise, the value is 0. Π0nc,ij, Π0c,ij, Π0ns,i and Π0s,i represent the outlet pressure setpoints of the non-electric-driven compressor station, the electric-driven compressor station, the non-electric-driven gas source and the electric-driven gas source, respectively. Πt n-ns,i and Πtn-s,i represent the node gas pressures of the non-electric-driven gas source and the electric-driven gas source, respectively. M t in-ns,i, M t in-s,i and M tout-l,i represent the pipeline natural gas flow rates of the non-electric-driven gas source, the electric-driven gas source and the natural gas load, respectively. M ns,i , M s,i These represent the upper and lower limits of the gas supply capacity of the non-electrically driven gas source and the electrically driven gas source, respectively; M l,i S represents the natural gas load; I S represents the set of pipe junctions; i→j S j→kLet S represent the sets of upstream nodes of natural gas inflow node j and downstream nodes of natural gas outflow node j, respectively; C S NC S S S NS S GL These represent the collections of electrically driven compressor stations, non-electrically driven compressor stations, electrically driven gas sources, non-electrically driven gas sources, and natural gas loads, respectively.

[0135] Among them, constraint (21) is the natural gas flow balance constraint; constraint (22) indicates that the outlet pressure of the non-electrically driven compressor station is always at the set value; constraints (23) and (24) indicate that when the electrically driven compressor station loses power supply, it enters the bypass mode, that is, the gas pressure at the beginning of the compressor station is equal to the gas pressure at the end. After the power supply is restored, the electrically driven compressor station will keep the outlet pressure at the set value; constraint (25) is the flow constraint of the compressor station; constraint (26) indicates that the outlet pressure of the non-electrically driven gas source is always at the set value; constraints (27) and (28) indicate that after the power supply is lost, the electrically driven gas source does not have the outlet pressure control capability. After the power supply is restored, the electrically driven gas source will keep the outlet pressure at the set value; constraints (29) and (30) are the upper and lower limits of gas source output constraints. For the electrically driven gas source, after the power supply is lost, it does not have the gas supply capability; constraint (31) is the natural gas consumption of the load node.

[0136] Among them, constraint (32) is the energy conversion relationship of the gas turbine unit; constraint (33) is the gas pressure requirement of the gas turbine unit for the gas supply node. The successful start-up and normal operation of the gas turbine unit require the gas supply pressure to reach a certain value. If the gas supply node pressure is too low, the gas turbine unit will experience operational failure or even shutdown. In order to deal with the numerical oscillation caused by differential discretization, the gas pressure of the gas supply node of the gas turbine unit is averaged over consecutive time periods; constraint (34) indicates that the natural gas supply of the gas turbine unit will not be interrupted after it is restored; constraint (35) indicates that the gas turbine unit should have natural gas supply conditions when it starts up.

[0137] Constructing coupling device constraints includes:

[0138] Gas turbine unit constraints:

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[0140]

[0141]

[0142]

[0143] In the formula: ut f,i is a 0-1 integer decision variable, representing whether the gas turbine unit has gas supply conditions; if it does, it takes the value 1, otherwise it takes the value 0; Pt g,i is the unit output; M tf,i represents the natural gas consumption of the gas turbine unit; k i Indicates the energy conversion parameters of the unit; The average gas pressure during the period when the gas supply nodes of the gas turbine unit are connected; Π f,i This refers to the minimum gas pressure requirement for the gas supply node of the gas turbine unit; S F This represents the collection of gas turbine units in the system;

[0144] Electric drive compressor station constraints:

[0145]

[0146]

[0147] In the formula: ut ld-c,ij represents the state of the load supplying power to the electric drive compressor station; constraint (36) indicates that the prerequisite for the electric drive compressor station to recover is that the load supplying it is restored, and constraint (37) indicates that the electric drive compressor station will not disconnect after the power supply is restored.

[0148] Electric drive air source constraints:

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[0150]

[0151] In the formula: ut ld-s,i represents the state of the load supplying power to the electric drive air source.

[0152] Constraint (38) indicates that the prerequisite for the electric drive air source to be restored is that the load supplying it is restored, and constraint (39) indicates that the electric drive air source will not be disconnected after the power supply is restored.

[0153] Example 2

[0154] This embodiment 2 provides a unit recovery optimization decision-making method considering the bidirectional coupling characteristics of the power transmission network and the gas transmission network. It mainly models the unit recovery problem considering the bidirectional coupling characteristics of the power transmission network and the gas transmission network, aiming to solve the problem that existing unit recovery methods are not applicable to highly coupled power transmission-gas transmission systems. The method of this embodiment includes objective function modeling, power transmission network constraint modeling, gas transmission network constraint modeling, and coupled equipment constraint modeling, as detailed below:

[0155] In this embodiment 2, the entire system recovery process is divided into T time periods, each with a length of Δt, and the set of all recovery time periods is S. TThe model's solution results represent the recovery strategies for the power transmission network at various time periods, namely, unit startup, path restoration, and load restoration status.

[0156] 1) Objective function

[0157] The objective function is set to maximize the power generation capacity of the transmission grid.

[13] Mathematically, it is represented as:

[0158]

[0159] In the formula: ut g,i are 0-1 integer decision variables representing the state of the unit; they are 1 if the unit has recovered, and 0 otherwise; C i Unit capacity; Pcrk i is the unit starting power; S NBS This refers to the set of non-black start units in the system.

[0160] 2) Transmission network constraint modeling

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[0163] res(x)=ceil(x)-x (4)

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[0177] In the formula: ut b,i, ut l,ij, and ut ld,ij are 0-1 integer decision variables, representing the state of the bus node, path, and load, respectively. If the state has recovered, the variable is 1; otherwise, it is 0. ut bg,i and ut b-ld,i represent the state of the bus node connected to the non-black start unit and load, respectively. tCH i and tCL i represent the maximum and minimum critical times that the unit must meet to start up, respectively. Pt ld,j represents the power of the load. Qt sys, Qmin g,i, Qcrk g,i, and Q ld,j These represent the system reactive power, the unit's minimum reactive power output, the unit's starting reactive power, and the load reactive power, respectively; B l,ij V represents the susceptance of the line; T represents the voltage level of the line. CL Indicates the latest recovery time for critical loads; S t S is the set of recovery periods up to time t; T S is the set of all recovery periods; G S BS S NBS S represents the set of all units, black-start units, and non-black-start units within the system, respectively; T / T represents the set of recovery periods excluding time period T; S L S B S L-B,i S B-BS S B / S B-BS Let S represent the path, bus node, path connected to bus node i, bus node connected to the black starter unit, and set of bus nodes excluding those connected to the black starter unit in the system; LD S CL These represent the sets of loads and critical loads in the system, respectively.

[0178] Constraint (2) is the linearized unit output function; constraints (3) and (4) are functions introduced by discretization and rounding, providing constant parameters for the constraint construction of the optimization model; (5) is the maximum and minimum critical time constraint that the unit startup must satisfy; constraints (6) and (7) are the recovery logic constraints for non-black start unit startup; constraints (8)-(11) are the path recovery logic constraints; constraints (12) and (13) indicate that the system should have sufficient reactive power balancing capacity to cope with the inductive reactive power generated by the unloaded lines and transformers; constraint (14) is the system active power constraint; constraints (15) and (16) are the load recovery logic constraints; constraint (17) indicates that the critical load must be restored before the set time.

[0179] 3) Gas transmission network constraint modeling

[0180] a) Dynamic constraints of pipelines

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[0184] In the formula: ρtn,i is the node density of natural gas; Πtn,i is the node pressure of natural gas; Mtin,ij and Mtout,ij represent the mass flow rates of natural gas flowing into and out of the pipeline, respectively; Li ij Δt is the differential space step size, i.e., the pipe length; Δt is the differential time step size, i.e., the recovery time period length; S N S represents the set of gas transmission nodes; P The collection of gas pipelines in the system; S T It is the set of all recovery periods.

[0185] Constraints (18)-(20) are a set of linear algebraic equations describing the dynamic distribution of natural gas energy flow, which respectively represent the continuity equation, momentum equation and gas state equation after differential separation.

[0186] b) Pipeline network boundary constraints and initial constraints

[0187] Based on the initial and boundary conditions given by the gas transmission pipeline network, the dynamic distribution of gas pressure and flow rate can be obtained by solving equations (18)-(20). The initial constraint refers to the previous steady-state value of the pipeline network. The boundary constraint refers to the boundary conditions at the end of the pipeline, including the flow balance constraint at the node, the gas pressure boundary, the flow rate boundary, and the gas supply limit of the gas source.

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[0194]

[0195]

[0196]

[0197]

[0198]

[0199] In the formula: ut c,ij and ut s,i are 0-1 integer decision variables, representing the power supply status of the electric-driven compressor station and the electric-driven gas source, respectively. If the power supply has been restored, the value is 1; otherwise, the value is 0. Π0 nc,ij, Π0 c,ij, Π0 ns,i and Π0 s,i represent the outlet pressure setpoints of the non-electric-driven compressor station, the electric-driven compressor station, the non-electric-driven gas source and the electric-driven gas source, respectively. Πt n-ns,i and Πt ns,i represent the node gas pressures of the non-electric-driven gas source and the electric-driven gas source, respectively. M t in-ns,i, M t in-s,i and M tout-l,i represent the pipeline natural gas flow rates of the non-electric-driven gas source, the electric-driven gas source and the natural gas load, respectively. M ns,i , M s,i These represent the upper and lower limits of the gas supply capacity of the non-electrically driven gas source and the electrically driven gas source, respectively; M l,i S represents the natural gas load; I S represents the set of pipe junctions; i→j S j→k Let S represent the sets of upstream nodes of natural gas inflow node j and downstream nodes of natural gas outflow node j, respectively; C S NC S S S NS S GL These represent the collections of electrically driven compressor stations, non-electrically driven compressor stations, electrically driven gas sources, non-electrically driven gas sources, and natural gas loads, respectively.

[0200] Constraint (21) is a natural gas flow balance constraint; constraint (22) indicates that the outlet pressure of the non-electrically driven compressor station is always at the set value; constraints (23) and (24) indicate that when the electrically driven compressor station loses power supply, it enters bypass mode, that is, the gas pressure at the beginning of the compressor station is equal to the gas pressure at the end. After the power supply is restored, the electrically driven compressor station will keep the outlet pressure at the set value; constraint (25) is a flow constraint of the compressor station; constraint (26) indicates that the outlet pressure of the non-electrically driven gas source is always at the set value; constraints (27) and (28) indicate that after the power supply is lost, the electrically driven gas source does not have the ability to control the outlet pressure. After the power supply is restored, the electrically driven gas source will keep the outlet pressure at the set value; constraints (29) and (30) are upper and lower limits of gas source output constraints. For the electrically driven gas source, after the power supply is lost, it does not have the ability to supply gas; constraint (31) is the natural gas consumption of the load node.

[0201] 4) Constraint modeling of coupled devices

[0202] a) Gas turbine unit

[0203]

[0204]

[0205]

[0206]

[0207] In the formula: ut f,i is a 0-1 integer decision variable, representing whether the gas turbine unit has gas supply conditions; if it does, it takes the value 1, otherwise it takes the value 0; Pt g,i is the unit output; M tf,i represents the natural gas consumption of the gas turbine unit; k i Indicates the energy conversion parameters of the unit; The average gas pressure during the period when the gas supply nodes of the gas turbine unit are connected; Π f,i This refers to the minimum gas pressure requirement for the gas supply node of the gas turbine unit; S F This represents the collection of gas turbine units in the system.

[0208] Constraint (32) is the energy conversion relationship of the gas turbine unit; Constraint (33) is the gas pressure requirement of the gas turbine unit for the gas supply node. The successful start-up and normal operation of the gas turbine unit require the gas supply pressure to reach a certain value. If the gas supply node pressure is too low, the gas turbine unit will experience operational failure or even shutdown. In order to deal with the numerical oscillation caused by differential discretization, the gas pressure of the gas supply node of the gas turbine unit is averaged over consecutive time periods; Constraint (34) indicates that the natural gas supply of the gas turbine unit will not be interrupted after it is restored; Constraint (35) indicates that the gas turbine unit should have natural gas supply conditions when it starts up.

[0209] b) Electric-driven compressor station

[0210]

[0211]

[0212] In the formula: ut ld-c,ij represents the state of the load supplying power to the electric compressor station.

[0213] Constraint (36) indicates that the prerequisite for the electric drive compressor station to be restored is that the load supplying it is restored, and constraint (37) indicates that the electric drive compressor station will not be disconnected after the power supply is restored.

[0214] c) Electric drive air source

[0215]

[0216]

[0217] In the formula: ut ld-s,i represents the state of the load supplying power to the electric drive air source.

[0218] Constraint (38) indicates that the prerequisite for the electric drive air source to be restored is that the load supplying it is restored, and constraint (39) indicates that the electric drive air source will not be disconnected after the power supply is restored.

[0219] In summary, the unit recovery problem, considering the bidirectional coupling characteristics of the two networks, is established as a mixed-integer linear programming model, as follows:

[0220] max(1)

[0221] st(2)-(39)

[0222] In this embodiment 2, the unit recovery optimization decision-making method that takes into account the bidirectional coupling characteristics of the transmission network and the gas transmission network is applied to... Figure 1 The test system shown.

[0223] exist Figure 1 In the test system shown, G1, G2, G4, G6, and G8 are gas turbine units; G10 is a black-start unit; loads 13 and 27 are critical loads; the latest recovery time (TLD) for critical loads is 180 minutes. In the gas transmission network system, CP1 and CP2 are both electrically driven compressor stations; GS3 is an electrically driven gas source, and other gas sources are non-electrically driven gas sources. After a major power outage, the transmission network needs to perform a black start. Black-start unit G10 successfully started at 0 minutes; the gas transmission network operates under low gas pressure levels and limited natural gas supply, affecting the recovery of the gas turbine units. The length of the recovery period t is 10 minutes, and the total recovery period T is 50 segments.

[0224] according to Figure 1 Based on the test system and scenario information shown, a mixed-integer linear programming model considering the bidirectional coupling characteristics of the power transmission network and the gas transmission network is established. The established model is solved to obtain strategies for unit startup, path restoration, and load (gas transmission network electric drive facilities) restoration.

[0225] The solution results are shown in Tables 1 and 2. It can be seen that the method in this embodiment effectively determines the unit recovery time, the power supply recovery time of the gas transmission network electric drive facilities, and the recovery time of the bus and line.

[0226] Table 1

[0227]

[0228]

[0229] Table 2

[0230]

[0231] Example 3

[0232] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, a unit recovery method considering the bidirectional coupling characteristics of the power transmission network and the gas transmission network is implemented. The method includes:

[0233] Determine the objective function for restoring the system's power generation capacity;

[0234] Construct power transmission network restoration constraints;

[0235] Constructing constraints for the gas transmission network;

[0236] Coupling constraints are constructed for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources.

[0237] Based on the objective function, and considering the constructed constraints of power transmission network recovery, gas transmission network, and coupling constraints of three types of coupled equipment—gas turbine units, electric-driven compressor stations, and electric-driven gas sources—a mixed-integer linear programming model is established.

[0238] Solve the mixed-integer linear programming model to obtain the recovery strategy for the power transmission network in each time period.

[0239] Example 4

[0240] Embodiment 4 of the present invention provides a computer program (product), including a computer program that, when run on one or more processors, is used to implement a unit recovery method taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network. The method includes:

[0241] Determine the objective function for restoring the system's power generation capacity;

[0242] Construct power transmission network restoration constraints;

[0243] Constructing constraints for the gas transmission network;

[0244] Coupling constraints are constructed for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources.

[0245] Based on the objective function, and considering the constructed constraints of power transmission network recovery, gas transmission network, and coupling constraints of three types of coupled equipment—gas turbine units, electric-driven compressor stations, and electric-driven gas sources—a mixed-integer linear programming model is established.

[0246] Solve the mixed-integer linear programming model to obtain the recovery strategy for the power transmission network in each time period.

[0247] Example 5

[0248] Embodiment 6 of the present invention provides an electronic device, including: a processor, a memory, and a computer program; wherein, the processor is connected to the memory, and the computer program is stored in the memory. When the electronic device is running, the processor executes the computer program stored in the memory to cause the electronic device to execute instructions for implementing a unit restoration method considering the bidirectional coupling characteristics of the power transmission network and the gas transmission network. The method includes:

[0249] Determine the objective function for restoring the system's power generation capacity;

[0250] Construct power transmission network restoration constraints;

[0251] Constructing constraints for the gas transmission network;

[0252] Coupling constraints are constructed for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources.

[0253] Based on the objective function, and considering the constructed constraints of power transmission network recovery, gas transmission network, and coupling constraints of three types of coupled equipment—gas turbine units, electric-driven compressor stations, and electric-driven gas sources—a mixed-integer linear programming model is established.

[0254] Solve the mixed-integer linear programming model to obtain the recovery strategy for the power transmission network in each time period.

[0255] 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 embodied 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.

[0256] 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.

[0257] 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.

[0258] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment, whereby a series of operational steps are performed 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.

[0259] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions disclosed in the present invention, various modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present invention.

Claims

1. A unit restoration method considering the bidirectional coupling characteristics of the power transmission network and the gas transmission network, characterized in that, include: Determine the objective function for restoring the system's power generation capacity; Construct power transmission network restoration constraints; Constructing constraints for the gas transmission network; Coupling constraints are constructed for three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources. Based on the objective function, and considering the constructed constraints of power transmission network recovery, gas transmission network, and coupling constraints of three types of coupled equipment—gas turbine units, electric-driven compressor stations, and electric-driven gas sources—a mixed-integer linear programming model is established. Solve the mixed-integer linear programming model to obtain the recovery strategy of the power transmission network in each time period; The objective function is set as maximizing the power generation capacity of the transmission network, mathematically expressed as: ； In the formula: For the 0-1 integer decision variable representing the unit's state, take 1 if it has recovered, otherwise take 0; C i Unit capacity; S is the unit's starting power. NBS This refers to the set of non-black start units in the system. Constructing coupling device constraints includes: Gas turbine unit constraints: ； ； ； ； In the formula: The decision variable is an integer from 0 to 1, indicating whether the gas generator unit has the conditions for gas supply. If it does, the value is 1; otherwise, the value is 0. To provide power to the generator unit; This indicates the natural gas consumption of the gas turbine unit; k i Indicates the energy conversion parameters of the unit; The average gas pressure during the period when the gas supply nodes of the gas turbine unit are connected; This refers to the minimum gas pressure requirement for the gas supply node of the gas turbine unit; S F S represents the set of gas turbine units in the system; T This is the set of all recovery periods; Electric drive compressor station constraints: ； ； In the formula: This indicates the status of the load supplying power to the electrically driven compressor station; S is a 0-1 integer decision variable representing the power supply status of the electric compressor station; it is set to 1 if the power supply has been restored, and 0 otherwise. C This represents a collection of electrically driven compressor stations; Electric drive air source constraints: ； ； In the formula: Indicates the state of the load supplying power to the electrically driven air source; S S This represents a collection of electrically driven air sources; The decision variable is an integer from 0 to 1, representing the power supply status of the electric drive gas source. If it has been restored, take 1; otherwise, take 0.

2. The unit restoration method considering the bidirectional coupling characteristics of the power transmission network and gas transmission network according to claim 1, characterized in that, Constructing power transmission network restoration constraints includes: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； In the formula: , , These are 0-1 integer decision variables, representing the status of the bus node, path, and load, respectively. If the status has been restored, the variable is set to 1; otherwise, it is set to 0. , These represent the status of the bus nodes connected to non-black start units and loads, respectively. , These represent the maximum critical time and minimum critical time that the unit must meet to start up; Indicates the power of the load; , , , These represent the system reactive power, the unit's minimum reactive power output, the unit's starting reactive power, and the load reactive power, respectively; B l,ij V represents the susceptance of the line; T represents the voltage level of the line. CL Indicates the latest recovery time for critical loads; S t S is the set of recovery periods up to time t; G S BS S NBS S represents the set of all units, black-start units, and non-black-start units within the system, respectively; T / T represents the set of recovery periods excluding time period T; S L S B S L-B,i S B-BS S B / S B-BS These represent the paths, bus nodes, paths connected to bus node i, bus nodes connected to the black starter unit, and the set of bus nodes excluding those connected to the black starter unit, respectively; SLD and SCL represent the sets of loads and critical loads in the system, respectively.

3. The unit restoration method considering the bidirectional coupling characteristics of the power transmission network and gas transmission network according to claim 2, characterized in that, Constructing gas transmission network constraints, including pipeline dynamic constraints: ； ； ； In the formula: Natural gas node density; This refers to the gas pressure at the natural gas node. , L represents the mass flow rate of natural gas flowing into and out of the pipeline, respectively. ij Δt is the differential space step size, i.e., the pipe length; Δt is the differential time step size, i.e., the recovery time period length; S N S represents the set of gas transmission nodes; P The collection of gas pipelines in the system.

4. The unit restoration method considering the bidirectional coupling characteristics of the power transmission network and gas transmission network according to claim 3, characterized in that, Constructing gas transmission network constraints also includes pipeline boundary constraints and initial constraints: Based on the initial and boundary conditions given by the gas transmission pipeline network, the dynamic distribution of gas pressure and flow rate is obtained by solving the dynamic constraints of the pipeline. The initial constraints refer to the previous steady-state values ​​of the pipeline network. The boundary constraints refer to the boundary conditions at the end of the pipeline, including the flow balance constraints at the nodes, the gas pressure boundary, the flow rate boundary, and the gas supply limit of the gas source. ； ； ； ； ； ； ； ； ； ； ； In the formula: , , , These represent the outlet pressure setpoints for the non-electrically driven compressor station, the electrically driven compressor station, the non-electrically driven air source, and the electrically driven air source, respectively. , These represent the node pressures of the non-electrically driven gas source and the electrically driven gas source, respectively. , , These represent the pipeline natural gas flow rates for non-electrically driven gas sources, electrically driven gas sources, and natural gas loads, respectively. ns,i , M ns,i , s,i , M s,i These represent the upper and lower limits of the gas supply capacity of the non-electrically driven gas source and the electrically driven gas source, respectively; M l,i S represents the natural gas load; I S represents the set of pipe junctions; i→j S j→k These represent the natural gas inflow nodes. upstream nodes and natural gas outflow nodes The set of downstream nodes; S C S NC S S S NS S GL These represent the collections of electrically driven compressor stations, non-electrically driven compressor stations, electrically driven gas sources, non-electrically driven gas sources, and natural gas loads, respectively.

5. A unit recovery system based on the method described in any one of claims 1-4, taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network, characterized in that, include: The determination module is used to determine the objective function for restoring the system's power generation capacity. The first construction module is used to construct power grid recovery constraints; The second building module is used to construct gas transmission network constraints; The third construction module is used to construct coupling constraints for three types of coupled devices: gas turbine units, electric-driven compressor stations, and electric-driven gas sources. The fourth construction module is used to combine the objective function and establish a mixed-integer linear programming model based on the constructed transmission network recovery constraints, gas transmission network constraints, and coupling constraints of three types of coupled equipment: gas turbine units, electric-driven compressor stations, and electric-driven gas sources. The calculation module is used to solve the mixed-integer linear programming model to obtain the recovery strategy of the power transmission network for each time period.

6. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium is used to store computer instructions, which, when executed by a processor, implement the unit recovery method as described in any one of claims 1-4, taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network.

7. A computer program product, characterized in that, Includes a computer program, which, when run on one or more processors, is used to implement the unit recovery method as described in any one of claims 1-4, taking into account the bidirectional coupling characteristics of the transmission network and the gas transmission network.

8. An electronic device, characterized in that, include: The electronic device includes a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to cause the electronic device to execute instructions for implementing the unit restoration method taking into account the bidirectional coupling characteristics of the power transmission network and the gas transmission network as described in any one of claims 1-4.

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