Method and system for evaluating toughness index of electrical integrated energy system

Abstract

The invention discloses an electrical integrated energy system toughness index evaluation method, which comprises the following steps: firstly, considering disaster-causing uncertainty of extreme disasters, and establishing a typical fault scene set of an electrical integrated energy system; secondly, considering dynamic and static characteristics and coupling constraints of an electric and gas heterogeneous energy flow system, constructing a numerical simulation model of the electrical integrated energy system under a fault condition, and simulating a cascade fault and energy supply recovery process of the system under a typical fault scene set; and finally, based on a simulation result, drawing a multi-stage toughness curve of the system, and constructing a multi-dimensional comprehensive evaluation index system of the electricity-gas dependency under a toughness perspective. The invention further discloses an electrical integrated energy system toughness index evaluation system, full-dimension quantitative analysis of the multi-energy dependency relationship under the fault working condition can be achieved, and weak links caused by multi-energy flow strong coupling can be effectively screened out.

Description

Technical Field

[0001] This invention relates to the field of integrated energy system optimization technology, and in particular to a method and system for evaluating the resilience index of an integrated electrical energy system. Background Technology

[0002] Frequent occurrences of uncertainties such as extreme weather, cyberattacks, and equipment failures seriously threaten the stable operation of integrated energy systems. Resilience assessment and vulnerability identification of integrated energy systems are fundamental to resilience planning and power restoration research. However, current research has significant shortcomings: First, existing studies mostly focus on overall system resilience assessment, lacking detailed and comprehensive modeling of the dynamic and static characteristics and deep coupling relationships of the electrical and gaseous heterogeneous subsystems under extreme faults, making it difficult to accurately assess the impact of multi-energy dependence on resilience. Second, there is a lack of assessment indicators and analytical methods for electrical-gas dependence from a resilience perspective, making it difficult to accurately locate vulnerabilities caused by multi-energy coupling. Therefore, proposing a resilience index and assessment method for electrical integrated energy systems that considers multi-energy dependence is of great significance for the resilience assessment and accurate identification of vulnerabilities in integrated energy systems. Summary of the Invention

[0003] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a method and system for evaluating the resilience of integrated electrical energy systems. It provides detailed modeling of the dynamic and static characteristics and deep coupling relationships of the electrical and gas heterogeneous subsystems under extreme fault scenarios, effectively assesses the impact of multi-energy dependencies on the resilience of integrated electrical energy systems, and simulates the cascading faults and power recovery process of the system under typical fault scenarios. Simultaneously, based on simulation results, it plots multi-stage resilience curves of the system and constructs a multi-dimensional comprehensive evaluation index system for electrical-gas dependencies from a resilience perspective. This system is an evaluation index and analysis method that considers electrical-gas dependencies and can identify system weaknesses caused by multi-energy coupling. It is of great significance for the resilience assessment and weakness identification of integrated energy systems.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A method for evaluating the resilience index of an integrated electrical energy system according to the present invention includes:

[0006] Considering the uncertainty of the causative force of extreme disaster events, a set of failure scenarios is generated. As input to the multi-energy cascade fault and power supply recovery model of the integrated electrical energy system;

[0007] Considering the dynamic and static characteristics and coupling constraints of the electric and gas heterogeneous energy flow system, a multi-energy cascade fault and power supply recovery model of the integrated electrical energy system is constructed. This model is used to simulate the multi-energy cascade fault and power supply recovery process of the integrated electrical energy system under typical fault scenario sets.

[0008] Based on the simulated multi-energy cascade fault and power supply recovery process, a multi-stage resilience curve of the integrated electrical energy system is plotted.

[0009] Based on the multi-stage resilience curve of the integrated electrical energy system, a multi-dimensional comprehensive evaluation index system for the electro-gas interdependence from a resilience perspective is constructed.

[0010] As a further optimization of the electrical integrated energy system resilience index assessment method described in this invention, a fault scenario set S is generated, including:

[0011] Step 1.1: Collect information on power lines;

[0012] Step 1.2: Define and initialize the fault scenario set based on the power line information;

[0013] Step 1.3: Simulate fault time and repair time to generate fault states, and then generate a set of fault scenarios.

[0014] As a further optimization of the electrical integrated energy system resilience index assessment method described in this invention, a fault scenario set is generated. include:

[0015] Step 1.1: Identify the set of all power lines in the distribution network. Right now Where ij represents a line in the distribution network; the duration of the entire process of an extreme disaster event is set. And the duration Δt of each scheduling period, thus determining the total number of scheduling periods.

[0016] Collect vulnerability information of power lines, including their disaster resistance and aging level; collect spatiotemporal evolution intensity of extreme disasters, including the intensity distribution and impact range of disasters over time.

[0017] Collect information on the repair speed of faulty lines by maintenance personnel. The repair speed information includes the number of maintenance personnel, their technical level, and the availability of maintenance equipment.

[0018] Step 1.2: Create an empty fault scenario set to store the generated fault scenarios;

[0019] Set the number of Monte Carlo simulation iterations M, which is the number of fault scenarios to be generated. For the m-th iteration, create a new fault scenario s, where m = 1, 2, ..., M.

[0020] For each line in the distribution network Initialize the fault state parameter ξ representing the fault state in each scheduling period t = 1, 2, ..., N. ij,s,t The initial value is set to 0, ξ ij,s,t =0 indicates a non-fault state;

[0021] Step 1.3: For each line Based on the collected spatiotemporal evolution intensity of extreme disasters and the vulnerability information of the lines, failure times are generated through random sampling or probability distribution models. If the generated fault time or This indicates that the line was not damaged during the disaster. in, Let be the repair time for line ij under the s-th fault scenario;

[0022] If line ij is damaged during a disaster, i.e. Based on the collected information on the repair speed of maintenance personnel on the faulty lines, the repair time is generated through random sampling or a probability distribution model. Repair time meets and

[0023] For each line like During the scheduling period Start to End, transfer the fault state parameter ξ of line ij. ij,s,t Set to 1 to represent a fault, i.e., ξ ij,s,t =1; During other scheduling periods, the fault status parameter of line ij remains at 0;

[0024] Add the generated fault scenario s to the fault scenario set. In the text, 's' includes each line. Fault state parameter ξ in the t-th scheduling period ij,s,t t = 1, 2, ..., N;

[0025] Step 1.4: Process the generated fault scenario set Verification is performed, and the parameters of the Monte Carlo simulation are adjusted based on the verification results. The fault scenario set is then regenerated until a fault scenario set that meets the preset requirements is obtained.

[0026] As a further optimization of the resilience assessment method for an integrated electrical energy system described in this invention, considering the dynamic and static characteristics and coupling constraints of the heterogeneous electrical and gas energy flow systems, a multi-energy cascade fault and power supply recovery model for the integrated electrical energy system is constructed, including:

[0027] Step 2.1: Quantify the system load loss under fault scenarios;

[0028] Under each fault scenario, the objective function of the multi-energy cascade fault and power supply recovery model for the integrated electrical energy system is to minimize the total multi-energy load reduction of the integrated energy system, i.e.:

[0029] min:f P +f G (1)

[0030] Weighted load reduction f in power distribution and natural gas systems P f G for:

[0031]

[0032] in, Represents the set of nodes in a power distribution system. Represents the set of scheduling periods; This represents the weighting factor for electrical load. The weighting coefficient represents the gas load; s represents each fault scenario. This indicates a reduction in active power by the electrical load. This indicates a reduction in gas flow due to gas load reduction, where t is the number of each scheduling period. It is a set of natural gas nodes;

[0033] Step 2.2: Operational constraints of the integrated electrical energy system considering air inertia

[0034] (1) Consider the power flow constraints of the power distribution system, including the active and reactive power balance constraints of power nodes, voltage drop constraints of power lines, power reduction constraints of power loads, gas turbine operation constraints, upper and lower limit constraints of node voltage in the power distribution system, upper and lower limit constraints of line current, upper and lower limit constraints of active and reactive power flow of lines, Spanning Tree constraints and virtual power constraints.

[0035] The active and reactive power balance constraints at a power node are:

[0036]

[0037]

[0038] The voltage drop constraint for power lines is:

[0039]

[0040] Where k: k→i represents a power line with node i as its end node; j: i→j represents a power line with node i as its first end node, and Iij,s,t It is a parameter used to measure the square of the current in a power line, V. i,s,t Let be the squared value of the voltage at node i; This refers to the active power output of the gas turbine. The active power input to the electro-gas conversion equipment; Cogeneration units have a specific output active power; Active power used to measure electrical load; This represents the reactive power corresponding to the electrical load; from the perspective of line parameters, R ij It is the marking for the resistance of power lines, X ij M, representing the reactance of the power line, is set to a sufficiently large positive number and used as a constraint or parameter. This indicates the active power output of the water pump. Represents the active power of the electric compressor. and These represent the active power flow passing through the power lines in different directions. and These are used to describe the reactive power flow through the power line in different directions; there exists a variable to characterize the reduction of reactive power by the power load. The reactive power output by the gas turbine; Indicates the reactive power generated by the combined heat and power unit; I ki,s,t R is a numerical value used to measure the square of the current in a power line ki. ki It is the marking for the kilometre resistance of a power line. X represents the input active power of the electric boiler. ki α represents the reactance of the power line ki. ij,s,t α represents the operational state variable of power line ij. ij,s,t =1 indicates running, α ij,s,t =0 indicates that it is not running, V j,s,t This represents the squared value of the voltage at node j;

[0041] Power reduction constraints for electrical loads:

[0042]

[0043] The operating constraints of the gas turbine include upper and lower limits for active power, unit ramp power, and reactive power:

[0044]

[0045]

[0046] in, This represents the set of gas turbine nodes in the power distribution system. Defined as the power factor of a gas turbine. This parameter represents the maximum output electrical power of the gas turbine. It indicates the maximum gradeability power of the gas turbine; at the same time, It is a 0-1 variable used to reflect the operating status of the gas turbine, where 1 corresponds to the operating status and 0 corresponds to the non-operating status; Let be the output electrical power of the gas turbine at time t-1 under fault scenario s;

[0047] The upper and lower limits of node voltage in the power distribution system are:

[0048]

[0049] The upper and lower limits of the line current are constrained as follows:

[0050]

[0051] The upper and lower limits of the active and reactive power flow of the line are:

[0052]

[0053] Among them, V i,min V is used to characterize the minimum value that a node voltage can reach. i,max This is used to represent the maximum value of the node voltage; for power line current, I... ij,min It is the identifier of its minimum value, I ij,max It is a manifestation of its maximum value. This refers to the maximum capacity of the power line;

[0054] Spanning Tree constraints and virtual power constraints:

[0055] In the virtual spanning tree, the power node and the load node are the root node and child nodes, respectively:

[0056]

[0057] The virtual power flow constraint for the virtual spanning tree is:

[0058]

[0059] Among them, f ki,s,t f is the virtual power flow of power line ki. ij,s,t Let y be the virtual power flow of power line ij. ji,s,t With y ij,s,t α is an auxiliary 0-1 variable representing the operating status of power lines, where 1 indicates connectivity and 0 indicates disconnection. ji,s,t β is a 0-1 variable representing the operational status of power lines. ji,s,tThe virtual power line is a 0-1 variable representing its operational status, where 0 indicates it is not operational and 1 indicates it is operational.

[0060] The actual power grid topology is a subgraph of a virtual spanning tree:

[0061]

[0062] Damaged power lines cannot be put into operation:

[0063]

[0064] in, ξ represents the set of power supply nodes within the power distribution system. For variables related to the state and operation of power lines, ξ ij,s,t Used to characterize the fault state of power lines; N P Let y represent the set of nodes in the power distribution system. ij,s,t This is an auxiliary 0-1 variable representing the operating status of power lines. A value of 1 indicates that the power line is connected, while a value of 0 indicates that the power line is not connected. ij,s,t It is a 0-1 variable representing the virtual power line's operational status. A value of 0 indicates that it is not operational, and a value of 1 indicates that it is operational.

[0065] (2) Natural gas system operation constraints, including natural gas fluid dynamics constraints, gas mass flow node balance constraints at natural gas pipeline junction nodes, upper and lower limit constraints on node gas pressure, upper and lower limit constraints on node gas flow, upper and lower limit constraints on natural gas gate station gas flow, upper and lower limit constraints on gas intake of cogeneration equipment, and upper and lower limit constraints on gas load reduction.

[0066] The hydrodynamic constraints of natural gas are:

[0067] The Navier-Stokes momentum equation is:

[0068]

[0069] The law of conservation of mass is:

[0070]

[0071]

[0072] The equation of state for natural gas is:

[0073]

[0074] Where t is the number of each scheduling period, t = 1, 2, ..., N; i' and j' represent the node codes; and i'j' represents the sequence number of the natural gas pipeline. The set of natural gas pipelines represents the set of natural gas nodes, and the set of natural gas nodes represents the set of natural gas nodes used for... Indicates the total duration of an extreme disaster event; regarding the physical parameters of natural gas pipelines, This represents the cross-sectional area of ​​the pipe. Indicates the diameter of the pipe. Indicates the length of the pipe. This represents the coefficient of friction of the pipe. The flow rate of the gas inside the pipeline is represented by Δt; the duration of the scheduling period is represented by c; and the speed of sound is represented by c. Regarding the parameters related to flow rate, gas pressure, and gas density, This represents the gas flow rate from natural gas pipeline i'j' during time period t. Let i'j' be the gas flow rate exiting the natural gas pipeline at time t+1. Let Pr be the gas flow rate from natural gas pipeline i'j' at time t. j',t+1 Let Pr be the air pressure at node j' during time period t+1. i',t+1 Let ρ be the air pressure at node i' during time period t+1. j',t+1 Let ρ be the air density at node j' in the (t+1)th time period. i',t+1 Let ρ be the air density at node i' in the (t+1)th time period. j',t Let ρ be the air density at node j' in time period t. i',t Let i' be the air density at node i' in time period t. Pr represents the gas flow rate into natural gas pipeline i'j' during time period t; i’,t and Pr j’,t Let ρ represent the air pressure at node i' and node j' in time period t, respectively. i’,s,t Pr represents the air density at node i' in time period t. i',s,t Let i' be the air pressure at node i' during time period t;

[0075] The gas mass flow rate equilibrium constraint at the natural gas pipeline junction is:

[0076]

[0077] In addition, the gas density and gas pressure at the natural gas gate station node are set to constant values:

[0078]

[0079] In addition, the operating constraints of the natural gas compressor are:

[0080]

[0081] in, Represents the set of gate station nodes in a natural gas system. The set represents the set of compressor nodes in the natural gas system. Regarding the set of natural gas pipelines, k':k'→i' represents the set of natural gas pipelines with node i' as the end node, and j':i'→j' represents the set of natural gas pipelines with node i' as the head node. Γ is used to characterize the gas flow rate corresponding to the natural gas load. Com This is the compressor's pressure coefficient. This indicates that the gas pressure at the natural gas gate station node remains constant. This indicates the maximum airflow that the compressor can achieve. Used to measure the gas flow rate at the gate station node; This indicates the gas flow rate input to the combined heat and power unit; This represents the input gas flow rate of the gas turbine. Defined as the output gas flow rate of an electro-gas conversion device. This indicates the air flow rate into the compressor. This represents the gas flow rate corresponding to the reduction in node gas load. It is a 0-1 variable used to reflect the operating status of the compressor. When its value is 1, it indicates that the compressor is running; when its value is 0, it indicates that the compressor is not running. This indicates the node pressure at the compressor inlet. This indicates the node pressure at the compressor outlet. This represents the output flow rate of pipe k'i' in time period t. This represents the output flow rate of pipe i'j' in time period t. Let k'i be the cross-sectional area of ​​pipe. Let i'j' be the cross-sectional area of ​​pipe i'j'; The gas pressure at the natural gas gate station node;

[0082] The upper and lower limits of the nodal pressure are:

[0083]

[0084] The upper and lower limits of the node airflow are constrained as follows:

[0085]

[0086] in, This represents the output flow rate of pipe i'j' in time period t;

[0087] The upper and lower limits of gas flow at natural gas gate stations are as follows:

[0088]

[0089] The upper and lower limits of the intake air volume for combined heat and power (CHP) equipment are as follows:

[0090]

[0091] in, For combined heat and power equipment nodes;

[0092] The upper and lower limits of the gas load reduction are expressed as follows:

[0093]

[0094] in, This is the minimum threshold that can be used to characterize the nodal pressure. This is used to represent the maximum threshold for node air pressure, and for pipeline air flow parameters, This represents the minimum airflow rate in the pipeline. This represents the maximum airflow rate in the pipeline. This indicates the maximum airflow that the gate station can withstand. This indicates the maximum limit value for the intake air volume of a combined heat and power (CHP) unit;

[0095] (3) Electro-gas multi-energy coupling constraints, which include the energy conversion relationship between the gas turbine and the electric-to-gas equipment, and the power consumption of the compressor;

[0096] Consider the coupling relationship between the power distribution system and the natural gas system as shown in equations (36)-(38):

[0097] Considering the energy conversion relationship between gas turbines and electric-to-gas conversion equipment:

[0098]

[0099] In addition, considering the power consumption of the compressor for:

[0100]

[0101] From the perspective of node set, the node set of the power distribution system's electricity-to-gas conversion equipment is used for... To refer to, the set of electro-gas conversion equipment nodes in a natural gas system is... The set of compressor nodes in the power distribution system is represented as follows: The set of compressor nodes in a natural gas system is From the perspective of coefficients and parameters, C g2e C is the gas-to-electricity coefficient. e2g The compressibility factor of the compressor is denoted by Z, its gas constant by R, and the average gas temperature by T. tem The isentropic coefficient is represented by ε; in terms of equipment conversion efficiency, η... GT η represents the conversion efficiency of the gas turbine. PtGη represents the conversion efficiency of the electro-gas conversion equipment. Com This represents the compressor's conversion efficiency; Let be the input gas flow rate of the gas turbine at node i. Let be the input gas flow rate of the electro-gas conversion device at node i. The active power input to the electro-gas conversion equipment.

[0102] As a further optimization of the electrical integrated energy system resilience assessment method described in this invention, a multi-dimensional comprehensive assessment index system for electro-gas interdependence from a resilience perspective is constructed. This index system includes:

[0103] 1) Electrical sensitivity during cascading fault phase:

[0104] During the cascading failure phase, there exists an indicator to measure the sensitivity between the rate of energy degradation in the natural gas system and the rate of power degradation in the power distribution system.

[0105]

[0106] in, The initial load supply level of the natural gas system. The load supply level at the lowest point of the natural gas system's power supply. The initial load supply level of the power distribution system, The load supply level at the lowest point of the power distribution system. The time when the electrical load supply level reaches its lowest point. The time it takes for power lines to be damaged due to extreme disasters. The time when the natural gas load supply level reaches its lowest point. The timeframe during which an extreme disaster causes damage to a natural gas pipeline;

[0107] 2) Electrical sensitivity during power restoration phase:

[0108] During the energy restoration phase, there exists an indicator to assess the sensitivity of the natural gas system's energy restoration speed to the power distribution system's power restoration speed.

[0109]

[0110] in, The time required for the electrical load supply level to fully recover. The time when the power load supply level begins to recover. The time required for the natural gas load supply level to fully recover. This refers to the time when the natural gas load supply level begins to recover;

[0111] 3) Cascaded failures in the natural gas system and delays in power restoration:

[0112] Equation (41) gives an index that measures the time delay in maintaining full-load operation of the natural gas system after a power failure. The value of this index is constrained by the inertial continuity characteristics of gas and the location of the power failure. Equation (42) presents an index that measures the difference between the power supply recovery time of the natural gas system and the power supply recovery time of the distribution system. Its magnitude is affected by the natural gas pipeline reconstruction rate;

[0113]

[0114]

[0115] 4) Electrical sensitivity throughout the disaster process:

[0116] Equation (43) gives the electrical sensitivity of the entire process of the index disaster. The expression is used to quantify the similarity of the multi-stage resilience curves of the power distribution system and the natural gas system throughout the entire process of extreme events, thereby measuring the degree of correlation between the natural gas system and the power distribution system.

[0117]

[0118] in, This indicates the load supply level of the power distribution system at time t. This represents the load supply level of the natural gas system at time t+τ, where τ is the time interval;

[0119] 5) Electrical-electrical node sensitivity throughout the disaster process:

[0120] In comprehensive energy system analysis, indicators It represents the electrical-electric node sensitivity of node i throughout the entire disaster process, based on the system level, and is used to assess the interdependence between electrical-electric subsystems;

[0121] Equation (44) extends Equation (43) to quantify the sensitivity of natural gas nodes to power outages;

[0122]

[0123] in, It is an index used to characterize the load supply level of an electricity node at time t. It is an indicator used to reflect the load supply level of the gas node at time t+τ;

[0124]

[0125] Where, N sThis represents the number of fault scenarios.

[0126] A system for assessing the resilience of an integrated electrical energy system, comprising:

[0127] The generation module is used to consider the disaster-causing uncertainty of extreme disaster events and generate a set of fault scenarios S, which serves as the input to the multi-energy cascade fault and power supply recovery model of the integrated electrical energy system.

[0128] A construction module is used to consider the dynamic and static characteristics and coupling constraints of the electric and gas heterogeneous energy flow system, and to build a multi-energy cascade fault and power supply recovery model of the integrated electrical energy system. This model is used to simulate the multi-energy cascade fault and power supply recovery process of the integrated electrical energy system under typical fault scenario sets.

[0129] The plotting module is used to plot multi-stage resilience curves of an integrated electrical energy system based on simulated multi-energy cascade faults and power recovery processes.

[0130] The assessment module is used to construct a multi-dimensional comprehensive assessment index system for the electro-gas interdependence from a resilience perspective, based on the multi-stage resilience curves of the integrated electrical energy system.

[0131] A computer device includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the computer program to implement the steps of the above-described method for assessing the resilience index of an integrated electrical energy system.

[0132] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method for assessing the resilience index of an integrated electrical energy system.

[0133] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0134] (1) Existing research mainly focuses on assessing the overall resilience properties of integrated energy systems, but fails to provide detailed modeling of the dynamic and static characteristics and deep coupling relationships of electric and gas heterogeneous subsystems under extreme failure scenarios, making it difficult to effectively assess the impact of multi-energy interdependence on the resilience of integrated energy systems. The model proposed in this invention provides a more comprehensive and detailed modeling of the dynamic and static characteristics and deep coupling relationships of heterogeneous energy flow systems.

[0135] (2) The lack of evaluation indicators and analysis methods for electro-pneumatic interdependence from a resilience perspective makes it difficult to accurately locate weak links caused by multi-energy coupling. Based on the geometric characteristics presented by the resilience curve, this invention proposes a set of electro-pneumatic interdependence evaluation indicators and their mathematical expressions from multiple dimensions such as time, space, system, and nodes. With the help of this system and expressions, it is possible to achieve a full-dimensional quantitative analysis of multi-energy interdependence under fault conditions, and effectively identify weak links caused by strong coupling of multi-energy flows. Attached Figure Description

[0136] Figure 1 This is a flowchart of the resilience index and evaluation method of the integrated electrical energy system considering multi-energy dependence. Detailed Implementation

[0137] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0138] like Figure 1 The flowchart shown illustrates the resilience index and evaluation method of the integrated electrical energy system considering multi-energy dependence according to the present invention, including the following steps:

[0139] Step 1: Consider the uncertainty of extreme disaster events and generate a set of failure scenarios. As input to the multi-energy cascade fault and power supply recovery model of the integrated electrical energy system.

[0140] Step 1.1: Identify the set of all power lines in the distribution network. Right now Where ij represents a line in the distribution network; the duration of the entire process of an extreme disaster event is set. And the duration Δt of each scheduling period, thus determining the total number of scheduling periods.

[0141] Collect vulnerability information of power lines, including their disaster resistance and aging level; collect spatiotemporal evolution intensity of extreme disasters, including the intensity distribution and impact range of disasters over time.

[0142] Collect information on the repair speed of faulty lines by maintenance personnel. The repair speed information includes the number of maintenance personnel, their technical level, and the availability of maintenance equipment.

[0143] Step 1.2: Create an empty fault scenario set to store the generated fault scenarios;

[0144] Set the number of Monte Carlo simulation iterations M, which is the number of fault scenarios to be generated. For the m-th iteration, create a new fault scenario s, where m = 1, 2, ..., M.

[0145] For each line in the distribution network Initialize the fault state parameter ξ representing the fault state in each scheduling period t = 1, 2, ..., N. ij,s,t The initial value is set to 0, ξ ij,s,t =0 indicates a non-fault state;

[0146] Step 1.3: For each line Based on the collected spatiotemporal evolution intensity of extreme disasters and the vulnerability information of the lines, failure times are generated through random sampling or probability distribution models. If the generated fault time or This indicates that the line was not damaged during the disaster. in, Let be the repair time for line ij under the s-th fault scenario;

[0147] If line ij is damaged during a disaster, i.e. Based on the collected information on the repair speed of maintenance personnel on the faulty lines, the repair time is generated through random sampling or a probability distribution model. Repair time meets and

[0148] For each line like During the scheduling period Start to End, transfer the fault state parameter ξ of line ij. ij,s,t Set to 1 to represent a fault, i.e., ξ ij,s,t =1; During other scheduling periods, the fault status parameter of line ij remains at 0;

[0149] Add the generated fault scenario s to the fault scenario set. In the text, 's' includes each line. Fault state parameter ξ in the t-th scheduling period ij,s,t ,t=1,2,…,N;

[0150] Step 1.4: Process the generated fault scenario set Verification is performed, and the parameters of the Monte Carlo simulation are adjusted based on the verification results. The fault scenario set is then regenerated until a fault scenario set that meets the preset requirements is obtained.

[0151] Step 2: Considering the dynamic and static characteristics and coupling constraints of the electric and gas heterogeneous energy flow system, construct a multi-energy cascade fault and power supply recovery model for the integrated electrical energy system. This model is used to simulate the multi-energy cascade fault and power supply recovery process of the integrated electrical energy system under typical fault scenario sets.

[0152] Step 2.1: Quantify the system load loss under fault scenarios;

[0153] Under each fault scenario, the objective function of the multi-energy cascade fault and power supply recovery model for the integrated electrical energy system is to minimize the total multi-energy load reduction of the integrated energy system, i.e.:

[0154] min:f P +f G (1)

[0155] Weighted load reduction f in power distribution and natural gas systems P f G for:

[0156]

[0157] in, Represents the set of nodes in a power distribution system. Represents the set of scheduling periods; This represents the weighting factor for electrical load. The weighting coefficient represents the gas load; s represents each fault scenario. This indicates a reduction in active power by the electrical load. This indicates a reduction in gas flow due to gas load reduction, where t is the number of each scheduling period. It is a set of natural gas nodes;

[0158] Step 2.2: Operational constraints of the integrated electrical energy system considering air inertia

[0159] (2) Consider the power flow constraints of the power distribution system, including the active and reactive power balance constraints of power nodes, voltage drop constraints of power lines, power reduction constraints of power loads, gas turbine operation constraints, upper and lower limit constraints of node voltage in the power distribution system, upper and lower limit constraints of line current, upper and lower limit constraints of active and reactive power flow of lines, Spanning Tree constraints and virtual power constraints.

[0160] The active and reactive power balance constraints at a power node are:

[0161]

[0162] The voltage drop constraint for power lines is:

[0163]

[0164] Where k: k→i represents a power line with node i as its end node; j: i→j represents a power line with node i as its first end node, and I ij,s,t It is a parameter used to measure the square of the current in a power line, V. i,s,t Let be the squared value of the voltage at node i; This refers to the active power output of the gas turbine. The active power input to the electro-gas conversion equipment; Cogeneration units have a specific output active power; Active power used to measure electrical load; This represents the reactive power corresponding to the electrical load; from the perspective of line parameters, R ij It is the marking for the resistance of power lines, X ij M, representing the reactance of the power line, is set to a sufficiently large positive number and used as a constraint or parameter. This indicates the active power output of the water pump. Represents the active power of the electric compressor. and These represent the active power flow passing through the power lines in different directions. and These are used to describe the reactive power flow through the power line in different directions; there exists a variable to characterize the reduction of reactive power by the power load. The reactive power output by the gas turbine; Indicates the reactive power generated by the combined heat and power unit; I ki,s,t R is a numerical value used to measure the square of the current in a power line ki. ki It is the marking for the kilometre resistance of a power line. X represents the input active power of the electric boiler. ki α represents the reactance of the power line ki. ij,s,t α represents the operational state variable of power line ij. ij,s,t =1 indicates running, α ij,s,t =0 indicates that it is not running, V j,s,t This represents the squared value of the voltage at node j;

[0165] Power reduction constraints for electrical loads:

[0166]

[0167] The operating constraints of the gas turbine include upper and lower limits for active power, unit ramp power, and reactive power:

[0168]

[0169]

[0170] in, This represents the set of gas turbine nodes in the power distribution system. Defined as the power factor of a gas turbine. This parameter represents the maximum output electrical power of the gas turbine. It indicates the maximum gradeability power of the gas turbine; at the same time, It is a 0-1 variable used to reflect the operating status of the gas turbine, where 1 corresponds to the operating status and 0 corresponds to the non-operating status; Let be the output electrical power of the gas turbine at time t-1 under fault scenario s;

[0171] The upper and lower limits of node voltage in the power distribution system are:

[0172]

[0173] The upper and lower limits of the line current are constrained as follows:

[0174]

[0175] The upper and lower limits of the active and reactive power flow of the line are:

[0176]

[0177] Among them, V i,min V is used to characterize the minimum value that a node voltage can reach. i,max This is used to represent the maximum value of the node voltage; for power line current, I... ij,min It is the identifier of its minimum value, I ij,max It is a manifestation of its maximum value. This refers to the maximum capacity of the power line;

[0178] Spanning Tree constraints and virtual power constraints:

[0179] In the virtual spanning tree, the power node and the load node are the root node and child nodes, respectively:

[0180]

[0181] The virtual power flow constraint for the virtual spanning tree is:

[0182]

[0183] Among them, f ki,s,t f is the virtual power flow of power line ki. ij,s,t Let y be the virtual power flow of power line ij. ji,s,t With y ij,s,tα is an auxiliary 0-1 variable representing the operating status of power lines, where 1 indicates connectivity and 0 indicates disconnection. ji,s,t β is a 0-1 variable representing the operational status of power lines. ji,s,t The virtual power line is a 0-1 variable representing its operational status, where 0 indicates it is not operational and 1 indicates it is operational.

[0184] The actual power grid topology is a subgraph of a virtual spanning tree:

[0185]

[0186] Damaged power lines cannot be put into operation:

[0187]

[0188] in, ξ represents the set of power supply nodes within the power distribution system. For variables related to the state and operation of power lines, ξ ij,s,t Used to characterize the fault state of power lines; N P Let y represent the set of nodes in the power distribution system. ij,s,t This is an auxiliary 0-1 variable representing the operating status of power lines. A value of 1 indicates that the power line is connected, while a value of 0 indicates that the power line is not connected. ij,s,t It is a 0-1 variable representing the virtual power line's operational status. A value of 0 indicates that it is not operational, and a value of 1 indicates that it is operational.

[0189] (2) Natural gas system operation constraints, including natural gas fluid dynamics constraints, gas mass flow node balance constraints at natural gas pipeline junction nodes, upper and lower limit constraints on node gas pressure, upper and lower limit constraints on node gas flow, upper and lower limit constraints on natural gas gate station gas flow, upper and lower limit constraints on gas intake of cogeneration equipment, and upper and lower limit constraints on gas load reduction.

[0190] The hydrodynamic constraints of natural gas are:

[0191] The Navier-Stokes momentum equation is:

[0192]

[0193] The law of conservation of mass is:

[0194]

[0195] The equation of state for natural gas is:

[0196]

[0197] Where t is the number of each scheduling period, t = 1, 2, ..., N; i' and j' represent the node codes; and i'j' represents the sequence number of the natural gas pipeline. The set of natural gas pipelines represents the set of natural gas nodes, and the set of natural gas nodes represents the set of natural gas nodes used for... Indicates the total duration of an extreme disaster event; regarding the physical parameters of natural gas pipelines, This represents the cross-sectional area of ​​the pipe. Indicates the diameter of the pipe. Indicates the length of the pipe. This represents the coefficient of friction of the pipe. The flow rate of the gas inside the pipeline is represented by Δt; the duration of the scheduling period is represented by c; and the speed of sound is represented by c. Regarding the parameters related to flow rate, gas pressure, and gas density, This represents the gas flow rate from natural gas pipeline i'j' during time period t. Let i'j' be the gas flow rate exiting the natural gas pipeline at time t+1. Let Pr be the gas flow rate from natural gas pipeline i'j' at time t. j',t+1 Let Pr be the air pressure at node j' during time period t+1. i',t+1 Let ρ be the air pressure at node i' during time period t+1. j',t+1 Let ρ be the air density at node j' in the (t+1)th time period. i',t+1 Let ρ be the air density at node i' in the (t+1)th time period. j',t Let ρ be the air density at node j' in time period t. i',t Let i' be the air density at node i' in time period t. Pr represents the gas flow rate into natural gas pipeline i'j' during time period t; i’,t and Pr j’,t Let ρ represent the air pressure at node i' and node j' in time period t, respectively. i’,s,t This represents the air density at node i' in time period t. Let i' be the air pressure at node i' during time period t;

[0198] The gas mass flow rate equilibrium constraint at the natural gas pipeline junction is:

[0199]

[0200]

[0201] In addition, the gas density and gas pressure at the natural gas gate station node are set to constant values:

[0202]

[0203] In addition, the operating constraints of the natural gas compressor are:

[0204]

[0205] in, Represents the set of gate station nodes in a natural gas system. The set represents the set of compressor nodes in the natural gas system. Regarding the set of natural gas pipelines, k':k'→i' represents the set of natural gas pipelines with node i' as the end node, and j':i'→j' represents the set of natural gas pipelines with node i' as the head node. Γ is used to characterize the gas flow rate corresponding to the natural gas load. Com This is the compressor's pressure coefficient. This indicates that the gas pressure at the natural gas gate station node remains constant. This indicates the maximum airflow that the compressor can achieve. Used to measure the gas flow rate at the gate station node; This indicates the gas flow rate input to the combined heat and power unit; This represents the input gas flow rate of the gas turbine. Defined as the output gas flow rate of an electro-gas conversion device. This indicates the air flow rate into the compressor. This represents the gas flow rate corresponding to the reduction in node gas load. It is a 0-1 variable used to reflect the operating status of the compressor. When its value is 1, it indicates that the compressor is running; when its value is 0, it indicates that the compressor is not running. This indicates the node pressure at the compressor inlet. This indicates the node pressure at the compressor outlet. This represents the output flow rate of pipe k'i' in time period t. A represents the output flow rate of pipe i'j' in time period t. k'i' Let A be the cross-sectional area of ​​pipe k'i'. i'j' Let Pr be the cross-sectional area of ​​pipe i'j'; i',s,t The gas pressure at the natural gas gate station node;

[0206] The upper and lower limits of the nodal pressure are:

[0207]

[0208] The upper and lower limits of the node airflow are constrained as follows:

[0209]

[0210] in, This represents the output flow rate of pipe i'j' in time period t;

[0211] The upper and lower limits of gas flow at natural gas gate stations are as follows:

[0212]

[0213] The upper and lower limits of the intake air volume for combined heat and power (CHP) equipment are as follows:

[0214]

[0215] in, For combined heat and power equipment nodes;

[0216] The upper and lower limits of the gas load reduction are expressed as follows:

[0217]

[0218] Among them, Pr i’,min Pr is the minimum threshold that can be used to characterize the nodal pressure. i’,max This is used to represent the maximum threshold for node air pressure, and for pipeline air flow parameters, This represents the minimum airflow rate in the pipeline. This represents the maximum airflow rate in the pipeline. This indicates the maximum airflow that the gate station can withstand. This indicates the maximum limit value for the intake air volume of a combined heat and power (CHP) unit;

[0219] (3) Electro-gas multi-energy coupling constraints, which include the energy conversion relationship between the gas turbine and the electric-to-gas equipment, and the power consumption of the compressor;

[0220] Consider the coupling relationship between the power distribution system and the natural gas system as shown in equations (36)-(38):

[0221] Considering the energy conversion relationship between gas turbines and electric-to-gas conversion equipment:

[0222]

[0223] In addition, considering the power consumption of the compressor for:

[0224]

[0225]

[0226] From the perspective of node set, the node set of the power distribution system's electricity-to-gas conversion equipment is used for... To refer to, the set of electro-gas conversion equipment nodes in a natural gas system is... The set of compressor nodes in the power distribution system is represented as follows: The set of compressor nodes in a natural gas system is From the perspective of coefficients and parameters, C g2e C is the gas-to-electricity coefficient.e2g The compressibility factor of the compressor is denoted by Z, its gas constant by R, and the average gas temperature by T. tem The isentropic coefficient is represented by ε; in terms of equipment conversion efficiency, η... GT η represents the conversion efficiency of the gas turbine. PtG η represents the conversion efficiency of the electro-gas conversion equipment. Com This represents the compressor's conversion efficiency; Let be the input gas flow rate of the gas turbine at node i. Let be the input gas flow rate of the electro-gas conversion device at node i. The active power input to the electro-gas conversion equipment.

[0227] Step 3: Based on the simulated multi-energy cascade failure and power supply recovery process, plot the multi-stage resilience curve of the integrated electrical energy system;

[0228] Based on the multi-stage resilience curves of integrated electrical energy systems, a multi-dimensional comprehensive evaluation index system for electro-gas interdependence from a resilience perspective is constructed. This index system includes:

[0229] 1) Electrical sensitivity during cascading fault phase:

[0230] During the cascading failure phase, there exists an indicator to measure the sensitivity between the rate of energy degradation in the natural gas system and the rate of power degradation in the power distribution system.

[0231]

[0232] in, The initial load supply level of the natural gas system. The load supply level at the lowest point of the natural gas system's power supply. The initial load supply level of the power distribution system, The load supply level at the lowest point of the power distribution system. The time when the electrical load supply level reaches its lowest point. The time it takes for power lines to be damaged due to extreme disasters. The time when the natural gas load supply level reaches its lowest point. The timeframe during which an extreme disaster causes damage to a natural gas pipeline;

[0233] 2) Electrical sensitivity during power restoration phase:

[0234] During the energy restoration phase, there exists an indicator to assess the sensitivity of the natural gas system's energy restoration speed to the power distribution system's power restoration speed.

[0235]

[0236] in, The time required for the electrical load supply level to fully recover. The time when the power load supply level begins to recover. The time required for the natural gas load supply level to fully recover. This refers to the time when the natural gas load supply level begins to recover;

[0237] 3) Cascaded failures in the natural gas system and delays in power restoration:

[0238] Equation (41) gives an index that measures the time delay in maintaining full-load operation of the natural gas system after a power failure. The value of this index is constrained by the inertial continuity characteristics of gas and the location of the power failure. Equation (42) presents an index that measures the difference between the power supply recovery time of the natural gas system and the power supply recovery time of the distribution system. Its magnitude is affected by the natural gas pipeline reconstruction rate;

[0239]

[0240] 4) Electrical sensitivity throughout the disaster process:

[0241] Equation (43) gives the electrical sensitivity of the entire process of the index disaster. The expression is used to quantify the similarity of the multi-stage resilience curves of the power distribution system and the natural gas system throughout the entire process of extreme events, thereby measuring the degree of correlation between the natural gas system and the power distribution system.

[0242]

[0243] in, This indicates the load supply level of the power distribution system at time t. This represents the load supply level of the natural gas system at time t+τ, where τ is the time interval;

[0244] 5) Electrical-electrical node sensitivity throughout the disaster process:

[0245] In comprehensive energy system analysis, indicators It represents the electrical-electric node sensitivity of node i throughout the entire disaster process, based on the system level, and is used to assess the interdependence between electrical-electric subsystems;

[0246] Equation (44) extends Equation (43) to quantify the sensitivity of natural gas nodes to power outages;

[0247]

[0248] in, It is an index used to characterize the load supply level of an electricity node at time t. It is an indicator used to reflect the load supply level of the gas node at time t+τ.

[0249]

[0250] Where, N s The number of failure scenarios;

[0251] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, it implements the steps of the method for evaluating the resilience index of an integrated electrical energy system as described in the first aspect above or any corresponding embodiment.

[0252] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the electrical integrated energy system resilience index assessment method as described in the first aspect above or any corresponding embodiment.

[0253] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0254] 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.

[0255] 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.

[0256] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0257] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0258] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for evaluating the resilience index of an integrated electrical energy system, characterized in that, include: Considering the uncertainty of the causative force of extreme disaster events, a set of failure scenarios is generated. As input to the multi-energy cascade fault and power supply recovery model of the integrated electrical energy system; Considering the dynamic and static characteristics and coupling constraints of the electric and gas heterogeneous energy flow system, a multi-energy cascade fault and power supply recovery model of the integrated electrical energy system is constructed. This model is used to simulate the multi-energy cascade fault and power supply recovery process of the integrated electrical energy system under typical fault scenario sets. Based on the simulation of multi-energy cascade faults and power supply recovery processes, multi-stage resilience curves of integrated electrical energy systems are plotted. Based on the multi-stage resilience curve of the integrated electrical energy system, a multi-dimensional comprehensive evaluation index system for the electro-gas interdependence from a resilience perspective is constructed.

2. The method for evaluating the resilience index of an integrated electrical energy system according to claim 1, characterized in that, Generate fault scenario set include: Step 1.1: Collect information on power lines; Step 1.2: Define and initialize the fault scenario set based on the power line information; Step 1.3: Simulate fault time and repair time to generate fault states, and then generate a set of fault scenarios.

3. The method for evaluating the resilience index of an integrated electrical energy system according to claim 1, characterized in that, Generate fault scenario set include: Step 1.1: Identify the set of all power lines in the distribution network. Right now Where ij represents a line in the distribution network; the duration of the entire process of an extreme disaster event is set. And the duration Δt of each scheduling period, thus determining the total number of scheduling periods. Collect vulnerability information of power lines, including their disaster resistance and aging level; collect spatiotemporal evolution intensity of extreme disasters, including the intensity distribution and impact range of disasters over time. Collect information on the repair speed of faulty lines by maintenance personnel. The repair speed information includes the number of maintenance personnel, their technical level, and the availability of maintenance equipment. Step 1.2: Create an empty fault scenario set to store the generated fault scenarios; Set the number of Monte Carlo simulation iterations M, which is the number of fault scenarios to be generated. For the m-th iteration, create a new fault scenario s, where m = 1, 2, ..., M. For each line in the distribution network Initialize the fault state parameter ξ representing the fault state in each scheduling period t = 1, 2, ..., N. ij,s,t The initial value is set to 0, ξ ij,s,t =0 indicates a non-fault state; Step 1.3: For each line Based on the collected spatiotemporal evolution intensity of extreme disasters and the vulnerability information of the lines, failure times are generated through random sampling or probability distribution models. If the generated fault time or This indicates that the line was not damaged during the disaster. in, Let be the repair time for line ij under the s-th fault scenario; If line ij is damaged during a disaster, i.e. Based on the collected information on the repair speed of maintenance personnel on the faulty lines, the repair time is generated through random sampling or a probability distribution model. Repair time meets and For each line like During the scheduling period Start to End, transfer the fault state parameter ξ of line ij. ij,s,t Set to 1 to represent a fault, i.e., ξ ij,s,t =1; During other scheduling periods, the fault status parameter of line ij remains at 0; Add the generated fault scenario s to the fault scenario set. In the text, 's' includes each line. Fault state parameter ξ in the t-th scheduling period ij,s,t t = 1, 2, ..., N; Step 1.4: Process the generated fault scenario set Verification is performed, and the parameters of the Monte Carlo simulation are adjusted based on the verification results. The fault scenario set is then regenerated until a fault scenario set that meets the preset requirements is obtained.

4. The method for evaluating the resilience index of an integrated electrical energy system according to claim 3, characterized in that, Considering the dynamic and static characteristics and coupling constraints of the electric and gas heterogeneous energy flow system, a multi-energy cascade fault and power supply recovery model for the integrated electrical energy system is constructed, including: Step 2.1: Quantify the system load loss under fault scenarios; Under each fault scenario, the objective function of the multi-energy cascade fault and power supply recovery model for the integrated electrical energy system is to minimize the total multi-energy load reduction of the integrated energy system, i.e.: min:f P +f G (1) Weighted load reduction f in power distribution and natural gas systems P f G for: in, Represents the set of nodes in a power distribution system. Represents the set of scheduling periods; This represents the weighting factor for electrical load. The weighting coefficient for the gas load is represented; s represents each fault scenario. This indicates a reduction in active power by the electrical load. This indicates a reduction in gas flow due to gas load, where t is the number of each scheduling period, t = 1, 2, ..., N. It is a set of natural gas nodes; Step 2.2: Operational constraints of the integrated electrical energy system considering air inertia (1) Consider the power flow constraints of the power distribution system, including the active and reactive power balance constraints of power nodes, voltage drop constraints of power lines, power reduction constraints of power loads, gas turbine operation constraints, upper and lower limit constraints of node voltage in the power distribution system, upper and lower limit constraints of line current, upper and lower limit constraints of line active and reactive power flow, Spanning Tree constraints and virtual power constraints. The active and reactive power balance constraints at a power node are: The voltage drop constraint for power lines is: Where k: k→i represents a power line with node i as its end node; j: i→j represents a power line with node i as its first end node, and I ij,s,t It is a parameter used to measure the square of the current in a power line ij, V i,s,t Let be the squared value of the voltage at node i; This refers to the active power output of the gas turbine. The active power input to the electro-gas conversion equipment; Cogeneration units have a specific output active power; Active power used to measure electrical load; This represents the reactive power corresponding to the electrical load; from the perspective of line parameters, R ij It is the marking for the resistance of power lines, X ij M, representing the reactance of the power line, is set to a sufficiently large positive number and used as a constraint or parameter. This indicates the active power output of the water pump. Represents the active power of the electric compressor. and These represent the active power flow passing through the power lines in different directions. and These are used to describe the reactive power flow through the power line in different directions; there exists a variable to characterize the reduction of reactive power by the power load. The reactive power output by the gas turbine; Indicates the reactive power generated by the combined heat and power unit; I ki,s,t R is a numerical value used to measure the square of the current in a power line ki. ki It is the marking for the kilometre resistance of a power line. X represents the input active power of the electric boiler. ki α represents the reactance of the power line ki. ij,s,t α represents the operational state variable of power line ij. ij,s,t =1 indicates running, α ij,s,t =0 indicates that it is not running, V j,s,t This represents the squared value of the voltage at node j; Power reduction constraints for electrical loads: The operating constraints of the gas turbine include upper and lower limits for active power, unit ramp power, and reactive power: in, This represents the set of gas turbine nodes in the power distribution system. Defined as the power factor of a gas turbine. This parameter represents the maximum output electrical power of the gas turbine. It indicates the maximum gradeability power of the gas turbine; at the same time, It is a 0-1 variable used to reflect the operating status of the gas turbine, where 1 corresponds to the operating status and 0 corresponds to the non-operating status; Let be the output electrical power of the gas turbine at time t-1 under fault scenario s; The upper and lower limits of node voltage in the power distribution system are: The upper and lower limits of the line current are constrained as follows: The upper and lower limits of the active and reactive power flow of the line are: Among them, V i,min V is used to characterize the minimum value that a node voltage can reach. i,max This is used to represent the maximum value of the node voltage; for power line current, I... ij,min It is the identifier of its minimum value, I ij,max It is a manifestation of its maximum value. This refers to the maximum capacity of the power line; Spanning Tree constraints and virtual power constraints: In the virtual spanning tree, the power node and the load node are the root node and child nodes, respectively: The virtual power flow constraint for the virtual spanning tree is: Among them, f ki,s,t f is the virtual power flow of power line ki. ij,s,t Let y be the virtual power flow of power line ij. ji,s,t With y ij,s,t α is an auxiliary 0-1 variable representing the operating status of power lines, where 1 indicates connectivity and 0 indicates disconnection. ji,s,t β is a 0-1 variable representing the operational status of power lines. ji,s,t The virtual power line is a 0-1 variable representing its operational status, where 0 indicates it is not operational and 1 indicates it is operational. The actual power grid topology is a subgraph of a virtual spanning tree: Damaged power lines cannot be put into operation: in, ξ represents the set of power supply nodes within the power distribution system. For variables related to the state and operation of power lines, ξ ij,s,t Used to characterize the fault state of power lines; N P Let y represent the set of nodes in the power distribution system. ij,s,t This is an auxiliary 0-1 variable representing the operating status of power lines. A value of 1 indicates that the power line is connected, while a value of 0 indicates that the power line is not connected. ij,s,t It is a 0-1 variable representing the virtual power line's operational status. A value of 0 indicates that it is not operational, and a value of 1 indicates that it is operational. (2) Natural gas system operation constraints, including natural gas fluid dynamics constraints, gas mass flow node balance constraints at natural gas pipeline junction nodes, upper and lower limit constraints on node gas pressure, upper and lower limit constraints on node gas flow, upper and lower limit constraints on natural gas gate station gas flow, upper and lower limit constraints on gas intake of cogeneration equipment, and upper and lower limit constraints on gas load reduction. The hydrodynamic constraints of natural gas are: The Navier-Stokes momentum equation is: The law of conservation of mass is: The equation of state for natural gas is: Where t is the number of each scheduling period, t = 1, 2, ..., N; i' and j' represent the node codes; and i'j' represents the sequence number of the natural gas pipeline. The set of natural gas pipelines represents the set of natural gas nodes, and the set of natural gas nodes represents the set of natural gas nodes used for... Indicates the total duration of an extreme disaster event; regarding the physical parameters of natural gas pipelines, This represents the cross-sectional area of ​​the pipe. Indicates the diameter of the pipe. Indicates the length of the pipe. This represents the coefficient of friction of the pipe. The flow rate of the gas inside the pipeline is represented by Δt; the duration of the scheduling period is represented by c; and the speed of sound is represented by c. Regarding the parameters related to flow rate, gas pressure, and gas density, This represents the gas flow rate from natural gas pipeline i'j' during time period t. Let i'j' be the gas flow rate exiting the natural gas pipeline at time t+1. Let Pr be the gas flow rate from natural gas pipeline i'j' at time t. j',t+1 Let Pr be the air pressure at node j' during time period t+1. i',t+1 Let ρ be the air pressure at node i' during time period t+1. j',t+1 Let ρ be the air density at node j' in the (t+1)th time period. i',t+1 Let ρ be the air density at node i' in the (t+1)th time period. j',t Let ρ be the air density at node j' in time period t. i',t Let i' be the air density at node i' in time period t. Pr represents the gas flow rate into natural gas pipeline i'j' during time period t; i’,t and Pr j’,t Let ρ represent the air pressure at node i' and node j' in time period t, respectively. i’,s,t Pr represents the air density at node i' in time period t. i',s,t Let i' be the air pressure at node i' during time period t; The gas mass flow rate equilibrium constraint at the natural gas pipeline junction is: In addition, the gas density and gas pressure at the natural gas gate station node are set to constant values: In addition, the operating constraints of the natural gas compressor are: in, Represents the set of gate station nodes in a natural gas system. The set represents the set of compressor nodes in the natural gas system. Regarding the set of natural gas pipelines, k':k'→i' represents the set of natural gas pipelines with node i' as the end node, and j':i'→j' represents the set of natural gas pipelines with node i' as the head node. Γ is used to characterize the gas flow rate corresponding to the natural gas load. Com This is the compressor's pressure coefficient. This indicates that the gas pressure at the natural gas gate station node remains constant. This indicates the maximum airflow that the compressor can achieve. Used to measure the gas flow rate at the gate station node; This indicates the gas flow rate input to the combined heat and power unit; This represents the input gas flow rate of the gas turbine. Defined as the output gas flow rate of an electro-gas conversion device. This indicates the air flow rate into the compressor. This represents the gas flow rate corresponding to the reduction in node gas load. It is a 0-1 variable used to reflect the operating status of the compressor. When its value is 1, it indicates that the compressor is running; when its value is 0, it indicates that the compressor is not running. This indicates the node pressure at the compressor inlet. This indicates the node pressure at the compressor outlet. This represents the output flow rate of pipe k'i' in time period t. A represents the output flow rate of pipe i'j' in time period t. k'i' Let A be the cross-sectional area of ​​pipe k'i'. i'j' Let Pr be the cross-sectional area of ​​pipe i'j'; i',s,t The gas pressure at the natural gas gate station node; The upper and lower limits of the nodal pressure are: The upper and lower limits of the node airflow are constrained as follows: in, This represents the output flow rate of pipe i'j' in time period t; The upper and lower limits of gas flow at natural gas gate stations are as follows: The upper and lower limits of the intake air volume for combined heat and power (CHP) equipment are as follows: in, For combined heat and power equipment nodes; The upper and lower limits of the gas load reduction are expressed as follows: Among them, Pr i’,min Pr is the minimum threshold that can be used to characterize the nodal pressure. i’,max This is used to represent the maximum threshold for node air pressure. For pipeline air flow parameters, This represents the minimum airflow rate in the pipeline. This represents the maximum airflow rate in the pipeline. This indicates the maximum airflow that the gate station can withstand. This indicates the maximum limit value for the intake air volume of a combined heat and power (CHP) unit; (3) Electro-gas multi-energy coupling constraints, which include the energy conversion relationship between the gas turbine and the electric-to-gas equipment, and the power consumption of the compressor; Consider the coupling relationship between the power distribution system and the natural gas system as shown in equations (36)-(38): Considering the energy conversion relationship between gas turbines and electric-to-gas conversion equipment: In addition, considering the power consumption of the compressor for: From the perspective of node set, the node set of the power distribution system's electricity-to-gas conversion equipment is used for... To refer to, the set of electro-gas conversion equipment nodes in a natural gas system is... The set of compressor nodes in the power distribution system is represented as follows: The set of compressor nodes in a natural gas system is From the perspective of coefficients and parameters, C g2e C is the gas-to-electricity coefficient. e2g The compressibility factor of the compressor is denoted by Z, its gas constant by R, and the average gas temperature by T. tem The isentropic coefficient is represented by ε; in terms of equipment conversion efficiency, η... GT η represents the conversion efficiency of the gas turbine. PtG η represents the conversion efficiency of the electro-gas conversion equipment. Com This represents the compressor's conversion efficiency; Let be the input gas flow rate of the gas turbine at node i. Let be the input gas flow rate of the electro-gas conversion device at node i. The active power input to the electro-gas conversion equipment.

5. The method for evaluating the resilience index of an integrated electrical energy system according to claim 4, characterized in that, A multidimensional comprehensive evaluation index system for electro-gas dependence from a resilience perspective is constructed, which includes: 1) Electrical sensitivity during cascading fault phase: During the cascading failure phase, there exists an indicator to measure the sensitivity between the rate of energy degradation in the natural gas system and the rate of power degradation in the power distribution system. in, The initial load supply level of the natural gas system. The load supply level at the lowest point of the natural gas system's energy supply. The initial load supply level of the power distribution system, The load supply level at the lowest point of the power distribution system. The time when the electrical load supply level reaches its lowest point. The time it takes for power lines to be damaged due to extreme disasters. The time when the natural gas load supply level reaches its lowest point. The timeframe during which an extreme disaster causes damage to a natural gas pipeline; 2) Electrical sensitivity during the power restoration phase: During the energy restoration phase, there exists an indicator to assess the sensitivity of the natural gas system's energy restoration speed to the power distribution system's power restoration speed. in, The time required for the electrical load supply level to fully recover. The time when the power load supply level begins to recover. The time required for the natural gas load supply level to fully recover. This refers to the time when the natural gas load supply level begins to recover; 3) Cascaded failures in the natural gas system and delays in power restoration: Equation (41) gives an index that measures the time delay in maintaining full-load operation of the natural gas system after a power failure. The value of this index is constrained by the inertial continuity characteristics of gas and the location of the power failure. Equation (42) presents an index that measures the difference between the power supply recovery time of the natural gas system and the power supply recovery time of the distribution system. Its magnitude is affected by the natural gas pipeline reconstruction rate; 4) Electrical sensitivity throughout the disaster process: Equation (43) gives the electrical sensitivity of the entire process of the index disaster. The expression is used to quantify the similarity of the multi-stage resilience curves of the power distribution system and the natural gas system throughout the entire process of extreme events, thereby measuring the degree of correlation between the natural gas system and the power distribution system. in, This indicates the load supply level of the power distribution system at time t. This represents the load supply level of the natural gas system at time t+τ, where τ is the time interval; 5) Electrical-electrical node sensitivity throughout the disaster process: In comprehensive energy system analysis, indicators It represents the electrical-electric node sensitivity of node i throughout the entire disaster process, based on the system level, and is used to assess the interdependence between electrical-electric subsystems; Equation (44) extends Equation (43) to quantify the sensitivity of natural gas nodes to power outages; in, It is an index used to characterize the load supply level of an electricity node at time t. It is an indicator used to reflect the load supply level of the gas node at time t+τ; Where, N s This represents the number of fault scenarios.

6. A system for evaluating the resilience of an integrated electrical energy system, characterized in that, include: The generation module is used to consider the catastrophic uncertainties of extreme disaster events and generate a set of failure scenarios. As input to the multi-energy cascade fault and power supply recovery model of the integrated electrical energy system; A construction module is used to consider the dynamic and static characteristics and coupling constraints of the electric and gas heterogeneous energy flow system, and to build a multi-energy cascade fault and power supply recovery model of the integrated electrical energy system. This model is used to simulate the multi-energy cascade fault and power supply recovery process of the integrated electrical energy system under typical fault scenario sets. The plotting module is used to plot multi-stage resilience curves of an integrated electrical energy system based on simulated multi-energy cascade faults and power recovery processes. The assessment module is used to construct a multi-dimensional comprehensive assessment index system for the electro-gas interdependence from a resilience perspective, based on the multi-stage resilience curves of the integrated electrical energy system.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for evaluating the resilience index of an integrated electrical energy system as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for evaluating the resilience index of an integrated electrical energy system as described in any one of claims 1 to 5.

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