Multi-stage resilience improvement method and terminal of an electric heat integrated energy system

Abstract

The application discloses a kind of multi-stage toughness promotion method and terminal of electric heat comprehensive energy system, with minimum load loss as target to establish objective function, in combination with the constraint condition of network topology of electric heat comprehensive energy system in multi-stage, the constraint condition of distribution system operation model, determine the constraint condition of regional heating system operation model, solve the multi-stage toughness promotion scheme of electric heat comprehensive energy system, realize the multi-stage collaborative toughness promotion of distribution system and regional heating system.Compared with the isolated consideration of distribution network reconstruction in the prior art, the collaborative reconstruction in the application not only redistributes the heat load between heat sources to improve the toughness of the regional heating system, but also optimizes and adjusts the heating structure of the regional heating system to match the network topology changes of the distribution system, effectively controls the fault spread between systems, improves the toughness of the park-level electric heat comprehensive energy system, and is beneficial to reducing the overall load loss of the system, ensuring safe and stable operation of the system.

Description

Technical Field

[0001] This invention relates to the field of operation and control technology of integrated energy systems, and in particular to a multi-stage resilience enhancement method and terminal for an integrated electrothermal energy system. Background Technology

[0002] Extreme natural disasters such as hurricanes, blizzards, and ice storms can cause widespread damage to critical energy supply facilities, such as power lines, natural gas and heating pipelines, leading to frequent power outages.

[0003] Under extreme natural disasters, widespread power outages occur frequently, seriously threatening the safe and reliable operation of integrated energy systems. Therefore, improving the resilience of energy systems has attracted widespread attention from researchers. In the study of power system resilience, resilience enhancement strategies can be divided into pre-disaster defense strategies, in-disaster response strategies, and post-disaster recovery strategies according to the timing of extreme events. Before a disaster, resilience is enhanced through technical measures such as reinforcing high-risk components and deploying flexible generation and maintenance resources. During a disaster, resilience is reduced by scheduling flexible resources such as distributed power sources and energy storage devices to ensure normal operation in non-faulty areas and reduce system load losses. After a disaster, the repair of faulty components and the enhancement of system resilience are achieved through the coordinated optimization of multiple recovery tasks, including maintenance, personnel scheduling, and power restoration. How to improve post-disaster system resilience is a key issue of current concern.

[0004] In recent years, the widespread application of coupled equipment such as combined heat and power (CHP) units and electric boilers (EB) has promoted the deep coupling of power distribution systems (PDS) and district heating systems (DHS). The complex coupling characteristics between subsystems have become a key factor influencing the resilience of integrated electric-thermal energy systems, for the following reasons: 1) PDS / DHS faults propagate to the other system through coupling elements; a single system failure may trigger a cascading failure. 2) Relying solely on single-system fault isolation may lead to fault propagation; for example, improper PDS switching operations may reduce the heat output power of the CHP unit, causing unnecessary heat load losses. 3) Only when the PDS and DHS operate in tandem can the emergency control capabilities of flexibility resources (such as the rapid adjustment capability of the CHP unit) be fully utilized. Therefore, it is necessary to implement coordinated fault recovery for electric-thermal coupled systems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a multi-stage resilience enhancement method and terminal for an integrated electrothermal energy system, which can enhance the resilience of the integrated electrothermal energy system and ensure the safe and stable operation of the system.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A multi-stage resilience enhancement method for an integrated electrothermal energy system includes the following steps:

[0008] Obtain the load loss of the comprehensive electrothermal energy, and establish an objective function with the minimum load loss as the objective;

[0009] Establish network topology constraints for the integrated electric and thermal energy system during the degradation, isolation, and recovery phases; determine the constraints for the power distribution system operation model; and determine the constraints for the district heating system operation model.

[0010] Based on the objective function and the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience enhancement scheme for the integrated electric and thermal energy system is calculated.

[0011] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows:

[0012] A multi-stage resilience enhancement terminal for an integrated electrothermal energy system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the aforementioned multi-stage resilience enhancement method for an integrated electrothermal energy system.

[0013] The beneficial effects of this invention are as follows: An objective function is established with the goal of minimizing load loss. By combining the network topology constraints of the integrated electric-thermal energy system at multiple stages and the constraints of the power distribution system operation model, the constraints of the district heating system operation model are determined. This allows for the solution of a multi-stage resilience enhancement scheme for the integrated electric-thermal energy system, achieving multi-stage coordinated resilience enhancement between the power distribution system and the district heating system. Compared to the isolated consideration of power distribution network reconfiguration in existing technologies, the coordinated reconfiguration in this invention not only enhances the resilience of the district heating system by redistributing heat load among heat sources, but also effectively controls the spread of system faults by optimizing and adjusting the heating structure of the district heating system to match changes in the power distribution system network topology. This enhances the resilience of the park-level integrated electric-thermal energy system, helps reduce the overall system load loss, and ensures the safe and stable operation of the system. Attached Figure Description

[0014] Figure 1 This is a flowchart of a multi-stage resilience enhancement method for an integrated electrothermal energy system according to an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram of a multi-stage resilience enhancement terminal for an integrated electrothermal energy system according to an embodiment of the present invention;

[0016] Label Explanation:

[0017] 1. A multi-stage resilience enhancement terminal for an integrated electrothermal energy system; 2. A memory; 3. A processor. Detailed Implementation

[0018] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0019] Please refer to Figure 1 This invention provides a multi-stage resilience enhancement method for an integrated electrothermal energy system, comprising the following steps:

[0020] Obtain the load loss of the comprehensive electrothermal energy, and establish an objective function with the minimum load loss as the objective;

[0021] Establish network topology constraints for the integrated electric and thermal energy system during the degradation, isolation, and recovery phases; determine the constraints for the power distribution system operation model; and determine the constraints for the district heating system operation model.

[0022] Based on the objective function and the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience enhancement scheme for the integrated electric and thermal energy system is calculated.

[0023] As described above, the beneficial effects of this invention are as follows: An objective function is established with the goal of minimizing load loss. By combining the network topology constraints of the integrated electric-thermal energy system at multiple stages and the constraints of the power distribution system operation model, the constraints of the district heating system operation model are determined. This allows for the solution of a multi-stage resilience enhancement scheme for the integrated electric-thermal energy system, achieving multi-stage coordinated resilience enhancement between the power distribution system and the district heating system. Compared to the isolated consideration of power distribution network reconfiguration in existing technologies, the coordinated reconfiguration in this invention not only enhances the resilience of the district heating system by redistributing heat load among heat sources, but also effectively controls the spread of faults between systems by optimizing and adjusting the heating structure of the district heating system to match changes in the power distribution system network topology. This enhances the resilience of the park-level integrated electric-thermal energy system, helps reduce the overall system load loss, and ensures the safe and stable operation of the system.

[0024] Furthermore, the objective function established with the goal of minimizing the load loss includes:

[0025] Establish an objective function that minimizes the load loss of the combined electrothermal energy source:

[0026]

[0027] In the formula, This represents the amount of electrical load loss during the fault phase t. a represents the amount of heat load loss during the failure phase t. T Indicates the electrical load weight, bT T represents the heat load weight. t p represents the start time of fault phase t. c Let c represent the probability of failure scenario c occurring, where C represents the set of failure scenarios.

[0028] As described above, establishing an objective function that minimizes the load loss of the integrated electric-thermal energy system facilitates the calculation of subsequent multi-stage resilience enhancement schemes for the integrated electric-thermal energy system.

[0029] Furthermore, after establishing the objective function with the goal of minimizing the load loss, the function also includes:

[0030] The overall unload rate during the recovery phase is calculated using the first resilience index, and the overall unload rate during the multi-phase fault recovery process is calculated using the second resilience index.

[0031] The first toughness index R r,c for:

[0032]

[0033] The second toughness index R c for:

[0034]

[0035] As described above, by calculating resilience indicators, we can verify the effectiveness of collaborative reconfiguration in improving system resilience.

[0036] Furthermore, the network topology constraints for establishing the integrated electrothermal energy system during the degradation phase include:

[0037] When a closed pipe or line fails, the nodes at both ends of the closed pipe or line are designated as the fault zone.

[0038] The nodes at both ends of a closed pipe or line are simultaneously divided into fault zones and non-fault zones;

[0039] When a combined heat and power (CHP) unit is designated as a fault zone in the power distribution system, the CHP units in the district heating system will also be designated as fault zones.

[0040] As described above, dividing the network into fault zones and non-fault zones for different operating conditions can yield network topology constraints for the degradation stage, which facilitates the subsequent generation of multi-stage resilience enhancement schemes.

[0041] Furthermore, the network topology constraints for establishing the integrated electrothermal energy system during the isolation phase include:

[0042] When a closed pipe or line fails, the closed pipe or line will be disconnected;

[0043] When the pipelines or lines in the fault area are repaired, the switches and valves are used for fault isolation, while the switches and valves in the non-fault area are used directly for fault isolation.

[0044] The nodes at both ends of a closed pipe or line are simultaneously divided into fault zones and non-fault zones;

[0045] When a combined heat and power (CHP) unit is designated as a fault zone in the power distribution system, the CHP units in the district heating system will also be designated as fault zones.

[0046] As described above, fault isolation for different operating conditions can yield network topology constraints for the isolation phase, facilitating the generation of multi-stage resilience enhancement schemes.

[0047] Furthermore, the network topology constraints for establishing the integrated electrothermal energy system during the recovery phase include:

[0048] When the pipelines or lines in the fault area are repaired, the switches and valves are used for fault recovery, while the switches and valves in the non-fault area are used directly for fault recovery.

[0049] Set the network topology of the power distribution system and the district heating system as radial constraints;

[0050] The faulty and non-faulty areas are separated during the isolation phase.

[0051] As described above, fault recovery is performed for different operating conditions, and the fault-free and non-fault-free zones divided during the isolation phase are not allowed to be reconnected. This allows for obtaining the network topology constraints during the recovery phase, which facilitates the subsequent generation of multi-stage resilience enhancement schemes.

[0052] Furthermore, the constraints for determining the power distribution system operation model include:

[0053] Determine the constraints of the node power balance equations, branch capacity constraints, combined heat and power unit power constraints, distributed generation power constraints, node load shedding constraints, and node voltage constraints for the power distribution system operation model.

[0054] Furthermore, the constraints for determining the operation model of the district heating system include:

[0055] Determine the constraints of the operating equations of the cogeneration units in the district heating system, the thermal power constraints of the cogeneration units, the thermal power constraints of the heat pumps, the heat loss equations of the heating network pipelines, the pipeline transmission capacity constraints, the node thermal balance constraints, and the node load shedding constraints.

[0056] As can be seen from the above description, the problem of heating network reconfiguration can be solved by the above constraints.

[0057] Furthermore, combining the objective function with the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, the multi-stage resilience enhancement scheme for the integrated electric and thermal energy system is calculated, including:

[0058] Using the interior point method, based on the objective function, and according to the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience improvement scheme for the integrated electric and thermal energy system is calculated.

[0059] The multi-stage resilience enhancement scheme for the integrated electric and thermal energy system includes the output power of the power distribution system and the network topology of the district heating system within the integrated electric and thermal energy system.

[0060] As described above, the interior point method can be used to solve for the strategy of improving the synergistic resilience of the integrated electric-thermal energy system, and realize the multi-stage synergistic resilience improvement of the power distribution system and the district heating system.

[0061] Please refer to Figure 2 Another embodiment of the present invention provides a multi-stage resilience enhancement terminal for an integrated electrothermal energy system, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the above-described multi-stage resilience enhancement method for an integrated electrothermal energy system.

[0062] The multi-stage resilience enhancement method and terminal for an integrated electric and thermal energy system described above are applicable to the formulation of resilience enhancement strategies for integrated electric and thermal energy systems. They are compatible with the original energy management systems of power systems and district heating systems, and help reduce the overall system load loss and ensure the safe and stable operation of the system. The following is a detailed description of the specific implementation methods:

[0063] Example 1

[0064] Please refer to Figure 1 A multi-stage resilience enhancement method for an integrated electrothermal energy system includes the following steps:

[0065] S1. Obtain the load loss of the comprehensive electric and thermal energy, and establish an objective function with the minimum load loss as the objective.

[0066] S11. Establishing an objective function with the goal of minimizing the load loss includes:

[0067] Establish an objective function that minimizes the load loss of the combined electrothermal energy source:

[0068]

[0069] In the formula, This represents the amount of electrical load loss during the fault phase t. a represents the amount of heat load loss during the failure phase t. T Indicates the electrical load weight, b T T represents the heat load weight. t p represents the start time of fault phase t. c Let c represent the probability of failure scenario c occurring, where C represents the set of failure scenarios.

[0070] S12. Calculate the overall unload rate during the recovery phase using the first resilience index, and calculate the overall unload rate during the multi-stage fault recovery process using the second resilience index.

[0071] Among them, the first toughness index R r,c for:

[0072]

[0073] The second toughness index R c for:

[0074]

[0075] In the formula, p L h represents the amount of electrical load loss. L This indicates the amount of heat load loss.

[0076] The above resilience indicators can be used to verify the effectiveness of collaborative reconfiguration in improving system resilience.

[0077] S2. Establish network topology constraints for the integrated electric and thermal energy system during the degradation, isolation, and recovery phases; determine the constraints for the power distribution system operation model; and determine the constraints for the district heating system operation model.

[0078] S21. The network topology constraints for establishing an integrated electrothermal energy system during the degradation phase include:

[0079] S211. When a closed pipe or line fails, the nodes at both ends of the closed pipe or line shall be designated as fault zones:

[0080]

[0081]

[0082] Where, k pipe k represents the set of power distribution system lines. lineLet C represent the set of pipes in the district heating system, C represent the set of fault scenarios, t represent the fault stage, and f represent the set of faults. ij,c Indicates the fault state of line / pipe (i,j), μ ij,0 Indicates the initial connection state of line / pipe (i,j), n i,c,t This indicates the fault state of node i in the power distribution / heating system during fault phase t, where n is the fault state. j,c,t The table represents the fault state of node j in the power distribution / heating system at fault stage t, where i represents the starting point of the line and j represents the ending point of the line.

[0083] S212. Divide the nodes at both ends of a closed pipe or line into fault zones and non-fault zones simultaneously:

[0084]

[0085]

[0086] S213. When a combined heat and power (CHP) unit is designated as a fault zone in the power distribution system, the CHP units in the district heating system shall also be designated as fault zones.

[0087]

[0088] In the formula, n m,c,t During the fault phase t, the CHP unit node m in the distribution network is in a fault state, n n,c,t During the fault phase, the CHP unit node n in the heating network is in a fault state. This represents the collection of combined heat and power (CHP) units in the power distribution system. This refers to the CHP set of combined heat and power units in the heating system.

[0089] S22. The network topology constraints for establishing an integrated electric and thermal energy system during the isolation phase include:

[0090] S221. When a closed pipe or line malfunctions, disconnect the closed pipe or line:

[0091]

[0092] In the formula, s ij,0 Indicates the configuration status of the line / pipe (i,j) switch, μ ij,c,t This indicates the connection status of line / pipe (i,j) during the fault phase.

[0093] S222. After the pipeline or line in the fault area is repaired, the switches and valves are used for fault isolation, and the switches and valves in the non-fault area are used directly for fault isolation.

[0094] To ensure the safety of maintenance personnel, switches / valves configured in the fault area can only be used for fault isolation after maintenance of the pipelines / lines within the fault area. Switches / valves configured in non-fault areas can be used directly for fault isolation.

[0095]

[0096]

[0097] S223. Divide the nodes at both ends of a closed pipe or line into fault zones and non-fault zones simultaneously:

[0098]

[0099]

[0100] S224. When a combined heat and power (CHP) unit is designated as a fault zone in the power distribution system, the CHP units in the district heating system shall also be designated as fault zones.

[0101]

[0102] S23. The network topology constraints for the integrated electric and thermal energy system during the recovery phase include:

[0103] S231. After the pipeline or line in the fault area has been repaired, the switches and valves shall be used for fault recovery, and the switches and valves in the non-fault area shall be used directly for fault recovery.

[0104]

[0105] S232. Set the network topology of the power distribution system and the district heating system as a radial constraint:

[0106]

[0107]

[0108] In the formula, k bus Let k represent the set of nodes in the power distribution system. nd ω represents the set of nodes in a district heating system. ij，c，t ω ji，c，t Both represent auxiliary variables, indicating the parent-child relationship between the nodes at both ends of line (i,j) during the fault recovery phase, ω. ij，c，t =1 indicates that node i is the parent node of node j, ω sj，c，t This represents the parent-child relationship between the nodes at both ends of line (s,j) during the fault recovery phase, ω. sj，c，t=1 indicates that node s is the parent node of node j, g j p j Representing the configuration status of node j (heat station / substation), γ j，c，t d j These represent the enabled and configured states of the distributed power source, respectively. π(j) represents the set of nodes at the beginning of the line with node j as the end node, and δ(j) represents the set of nodes at the end of the line with node j as the beginning node.

[0109] S233. Screening out fault areas and non-fault areas divided during the isolation phase:

[0110]

[0111]

[0112] S24. The constraints for determining the operation model of the power distribution system include:

[0113] Determine the constraints of the node power balance equations, branch capacity constraints, combined heat and power unit power constraints, distributed generation power constraints, node load shedding constraints, and node voltage constraints for the power distribution system operation model.

[0114] Specifically, the node power balance equation is as follows:

[0115]

[0116]

[0117]

[0118] In the formula, A represents the node-branch matrix of the power grid. These represent the corrected active and reactive power injected into the nodes, respectively. These represent the active and reactive power flow of the corrected line, respectively. These represent the corrected active and reactive power outputs of CHP and DG, respectively. These represent the corrected active and reactive power demand and load shedding of the node load, respectively. The corrected power value is the ratio of the actual power to the node voltage.

[0119] Branch capacity constraints: The power transmission of disconnected / faulted transmission lines is zero, and the power transmission of closed transmission lines is not allowed to exceed its limit.

[0120]

[0121]

[0122]

[0123] In the formula, AoB represents the Hadamard product of matrices, i.e., AoB = (a ij *b ij F represents the sending-end node-branch matrix of the power grid. Indicates the transmission capacity limit of the power transmission line. This represents the corrected node voltage value, which is the derivative of the actual node voltage, and M represents a sufficiently large constant.

[0124] CHP power constraints: Within the fault zone, the active and reactive power of CHP units are zero; within the non-fault zone, the active and reactive power of CHP units are between the set safe operating upper and lower limits.

[0125]

[0126]

[0127]

[0128] In the formula, Represents the CHP-grid node matrix, p CHP , Indicates the upper and lower limits of CHP active power. q CHP , This indicates the upper and lower limits of CHP reactive power, and n indicates the region to which the heating network node belongs. 1 indicates that the node belongs to the fault zone, and 0 indicates that the node belongs to the non-fault zone.

[0129] DG (Distributed Generation) power constraints: Within the fault zone, the active and reactive power of the DG is zero; within the non-fault zone, the active and reactive power of the DG is between the set safe operating upper and lower limits.

[0130]

[0131]

[0132]

[0133] In the formula, Denotes the DG-grid node matrix, p DG , This indicates the upper and lower limits of the active power of the DG. q DG , This indicates the upper and lower limits of the reactive power of the DG.

[0134] Node load loss constraint: All electrical loads within the fault zone will be lost, while the node load loss in the non-fault zone is less than or equal to the node load.

[0135]

[0136]

[0137]

[0138]

[0139] Node voltage constraint: The corrected node voltage amplitude within the fault zone is set to 1.

[0140]

[0141]

[0142] In the formula, This indicates the corrected voltage amplitude when the node is located in the fault zone;

[0143] The voltage amplitude at nodes within the non-faulty zone is within the upper and lower limits of the set safe operating voltage for the power system. u between:

[0144]

[0145]

[0146]

[0147] In the formula, This indicates the corrected voltage amplitude when the node is located in the non-fault zone. This indicates the corrected node voltage magnitude. u This indicates the upper and lower limits of the allowed voltage at the node.

[0148] The node voltage of a closed transmission line must meet the branch power flow constraints:

[0149]

[0150] In the formula, A e To represent the power grid node-branch matrix, r and x represent the resistance and reactance of the transmission line.

[0151] S25. The constraints for determining the operation model of the power distribution system include:

[0152] Determine the constraints of the node power balance equations, branch capacity constraints, combined heat and power unit power constraints, distributed generation power constraints, node load shedding constraints, and node voltage constraints for the power distribution system operation model.

[0153] Specifically, equality and inequality constraints are set for the safe operation of the district heating system. Due to the changes in hydraulic conditions brought about by the reconfiguration of the heating network, the direction of circulating water flow in the heating network is variable, making it impossible to determine the mixing nodes and thus impossible to establish a mixing constraint model. Because the hydraulic conditions (variable flow rate) are considered, the model contains a large number of bilinear and exponential terms, exhibiting strong nonlinearity. Furthermore, the reconfiguration of the heating network itself introduces 0 and 1 variables such as valve opening and closing, making the model a mixed-integer strongly nonlinear (non-convex) model. This poses a significant challenge to solving and engineering applications of multi-stage coordinated fault recovery problems in integrated electric-thermal energy systems. Therefore, energy flow (EF) model constraints are considered, including:

[0154] Operating characteristic equation constraints of the coupling element between the power system and the district heating system—the combined heat and power (CHP) unit in the district heating system:

[0155] p CHP ≤diag( χ 1, χ 2,... χ n )h CHP ,

[0156] p CHP ≥diag( χ 1, χ 2,... χ n )h CHP ,

[0157] In the formula, p CHP This indicates the active power of the CHP unit, h CHP This indicates the thermal power of the CHP unit. χ i This represents the reciprocal of the heat-to-power ratio of the i-th CHP unit. The heat-to-power ratio of the CHP unit can be obtained from the manufacturer's instruction manual for the CHP unit.

[0158] Thermal power constraints of CHP units in district heating systems:

[0159] The thermal power of the CHP units in the fault zone is zero, while the thermal power of the CHP units in the non-fault zone is within the set safe operating upper and lower limits. h CHP , between:

[0160]

[0161] In the formula, Represents the CHP unit-heating network node correlation matrix, h CHP This indicates the lower limit of the safe operating temperature range for the thermal power of the CHP unit. This indicates the upper limit of the safe operation of the thermal power of the CHP unit, where n represents the region to which the heating network node belongs, 1 indicates that the node belongs to the fault zone, and 0 indicates that the node belongs to the non-fault zone.

[0162] Heat pump (HB) thermal power constraint in district heating systems:

[0163] The thermal power of HB in the fault zone is zero, while the thermal power of HB in the non-fault zone is within the set safe operating upper and lower limits h. HB , between:

[0164]

[0165] In the formula, H represents the HB-heat network node correlation matrix. HB HB represents thermal power, h HB This indicates the lower limit of the safe operating temperature range for HB's thermal power. This indicates the upper limit of the safe operation of HB's thermal power.

[0166] The relationship between HB thermal power and fuel consumption: h HB =ηof HB ;

[0167] In the formula, f HB This indicates the fuel consumption of HB, and η represents the ratio of HB's thermal power to its fuel consumption. η can be obtained from HB's manufacturer's instructions.

[0168] Constraints on the heat loss equation of the heating network pipeline in the district heating system:

[0169] In the formula, This represents the usable thermal power of the circulating water at the beginning of the heating network pipeline, which is the difference between the thermal power contained in the working fluid flow at the beginning of the supply water network and the thermal power contained in the corresponding working fluid flow in the return water network. This indicates the heat power loss of circulating water at the beginning and end of the pipeline.

[0170] Pipeline heat transfer capacity constraints: The heat transfer power of an open / faulty pipeline is zero; the heat transfer power of a closed pipeline is not allowed to exceed its limit.

[0171] In the formula, This indicates the upper limit of the usable thermal power of the circulating water at the beginning and end of the pipeline, in μ. i j indicates the on / off state of the pipeline.

[0172] Nodal thermal balance constraints:

[0173]

[0174] hHS =h CHP +h HB ,

[0175] In the formula, F h ,T h This represents the node-branch matrix of a district heating system. Represents the heat station node matrix, h HS Indicates the output heat power of the heating station, h L h Loss These represent the node's heat load demand and load loss, respectively.

[0176] Node load loss constraint: All electrical loads within the fault zone will be lost, while the node load loss in the non-fault zone is less than or equal to the node load.

[0177] -M(1-n)≤h L -h Loss ≤M(1-n),

[0178] 0≤h Loss ≤h L .

[0179] S3. Combining the objective function with the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience improvement scheme for the integrated electric and thermal energy system is calculated.

[0180] Specifically, using the interior point method, based on the objective function, and according to the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience improvement scheme for the integrated electric and thermal energy system is calculated.

[0181] The multi-stage resilience enhancement scheme for the integrated electric and thermal energy system includes the output power of the power distribution system, the district heating system network topology, and the output power of the substation, DG, CHP units, and electric boilers within the integrated electric and thermal energy system.

[0182] Therefore, this embodiment considers the close coupling and mutual influence of the electric heating system, realizing multi-stage collaborative resilience enhancement of the power distribution system and the district heating system. Compared with isolated consideration of power distribution network reconfiguration, collaborative reconfiguration not only improves the resilience of the DHS by redistributing heat load among heat sources, but also enhances the resilience of the campus-level integrated electric-heat energy system by optimizing and adjusting the DHS heating structure to match changes in the PDS network topology and effectively preventing fault propagation between systems. This embodiment can be practically applied to the formulation of resilience enhancement strategies for integrated electric-heat energy systems, is compatible with the original power system and district heating system energy management system, and helps reduce the overall system load loss, ensuring the safe and stable operation of the system.

[0183] Example 2

[0184] Please refer to Figure 2 A multi-stage resilience enhancement terminal 1 for an integrated electrothermal energy system includes a memory 2, a processor 3, and a computer program stored in the memory 2 and executable on the processor 3. When the processor 3 executes the computer program, it implements the various steps of the multi-stage resilience enhancement method for an integrated electrothermal energy system according to Embodiment 1.

[0185] In summary, this invention provides a multi-stage resilience enhancement method and terminal for an integrated electric and thermal energy system. It establishes an objective function with the goal of minimizing load loss, and combines the network topology constraints of the integrated electric and thermal energy system at multiple stages with the constraints of the power distribution system operation model to determine the constraints of the district heating system operation model. This allows for the solution of a multi-stage resilience enhancement scheme for the integrated electric and thermal energy system, achieving multi-stage coordinated resilience enhancement of the power distribution system and the district heating system. Compared to the isolated consideration of power distribution network reconfiguration in existing technologies, the coordinated reconfiguration in this invention not only enhances the resilience of the district heating system by redistributing heat load among heat sources, but also effectively controls the spread of system faults by optimizing and adjusting the heating structure of the district heating system to match changes in the power distribution system network topology. This improves the resilience of the park-level integrated electric and thermal energy system, helps reduce the overall system load loss, and ensures the safe and stable operation of the system.

[0186] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A multi-stage resilience enhancement method for an integrated electrothermal energy system, characterized in that, Including the following steps: Obtain the load loss of the comprehensive electrothermal energy, and establish an objective function with the minimum load loss as the objective; Establish network topology constraints for the integrated electric and thermal energy system during the degradation, isolation, and recovery phases; determine the constraints for the power distribution system operation model; and determine the constraints for the district heating system operation model. Based on the objective function and the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience enhancement scheme for the integrated electric and thermal energy system is calculated. The objective function established with the goal of minimizing the load loss includes: Establish an objective function that minimizes the load loss of the combined electrothermal energy source: ； In the formula, This represents the amount of electrical load loss during the fault phase t. a represents the amount of heat load loss during the failure phase t. T Indicates the electrical load weight, b T T represents the heat load weight. t p represents the start time of fault phase t. c Let c represent the probability of failure scenario c occurring, and C represent the set of failure scenarios. The network topology constraints for establishing the integrated electrothermal energy system during the degradation phase include: When a closed pipe or line fails, the nodes at both ends of the closed pipe or line are designated as the fault zone. The nodes at both ends of a closed pipe or line are simultaneously divided into fault zones and non-fault zones; When a combined heat and power (CHP) unit is classified as a fault zone in the power distribution system, the CHP units in the district heating system will also be classified as fault zones. The network topology constraints for establishing the integrated electrothermal energy system during the isolation phase include: When a closed pipe or line fails, the closed pipe or line will be disconnected; When the pipelines or lines in the fault area are repaired, the switches and valves are used for fault isolation, while the switches and valves in the non-fault area are used directly for fault isolation. The nodes at both ends of a closed pipe or line are simultaneously divided into fault zones and non-fault zones; When a combined heat and power (CHP) unit is classified as a fault zone in the power distribution system, the CHP units in the district heating system will also be classified as fault zones. The network topology constraints for establishing the integrated electrothermal energy system during the recovery phase include: When the pipelines or lines in the fault area are repaired, the switches and valves are used for fault recovery, while the switches and valves in the non-fault area are used directly for fault recovery. Set the network topology of the power distribution system and the district heating system as radial constraints; Screen out faulty and non-faulty areas defined during the isolation phase; The constraints for determining the operation model of the power distribution system include: Determine the constraints of the node power balance equation, branch capacity, combined heat and power unit power, distributed generation power, node load shedding, and node voltage in the power distribution system operation model. The constraints for determining the operation model of the district heating system include: Determine the constraints of the operating equations of the cogeneration units in the district heating system, the thermal power constraints of the cogeneration units, the thermal power constraints of the heat pumps, the heat loss equations of the heating network pipelines, the pipeline transmission capacity constraints, the node thermal balance constraints, and the node load shedding constraints.

2. The multi-stage resilience enhancement method for an integrated electrothermal energy system according to claim 1, characterized in that, After establishing the objective function with the goal of minimizing the load loss, the following is also included: The overall unload rate during the recovery phase is calculated using the first resilience index, and the overall unload rate during the multi-phase fault recovery process is calculated using the second resilience index. The first toughness index R r,c for: ； The second toughness index R c for: ； In the formula, p L h represents the amount of electrical load loss. L This indicates the amount of heat load loss.

3. The multi-stage resilience enhancement method for an integrated electrothermal energy system according to claim 1, characterized in that, Based on the objective function and the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, the multi-stage resilience improvement scheme for the integrated electric and thermal energy system is calculated, including: Using the interior point method, based on the objective function, and according to the constraints of the integrated electric and thermal energy system, the power distribution system, and the district heating system, a multi-stage resilience improvement scheme for the integrated electric and thermal energy system is calculated. The multi-stage resilience enhancement scheme for the integrated electric and thermal energy system includes the output power of the power distribution system and the network topology of the district heating system within the integrated electric and thermal energy system.

4. A multi-stage resilience enhancement terminal for an integrated electrothermal energy system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements each step of the multi-stage resilience enhancement method for an integrated electrothermal energy system as described in any one of claims 1 to 3.

Images