Multi-time scale and coupling fault considering multi-energy security evaluation method and system

Abstract

This invention proposes a multi-energy safety assessment method and system considering multiple time scales and coupled faults. The method includes: establishing an intermediate time-scale model and a long-time-scale model of the integrated energy system; conducting a safety assessment for each fault scenario in a fault scenario set; wherein, using the long-time-scale model to perform an N-1 safety scan of the fault scenarios considering coupled faults, calculating system risk assessment indicators; when the system risk assessment indicators reflect that the fault scenario may lead to water hammer consequences, using the intermediate time-scale model to calculate the overpressure value generated during the water hammer process; and generating the final safety assessment result of the integrated energy system based on the safety assessment results of each fault scenario. This invention can capture the water hammer effect of the heating network and the cascading faults caused by the coupling of the logical and geographical layers, which are often overlooked in traditional assessments, achieving a more comprehensive and accurate safety assessment of the integrated energy system and helping to improve the operational safety of the system.

Description

Technical Field

[0001] This invention belongs to the field of integrated energy system operation and control technology, and specifically relates to a multi-energy safety assessment method and device that considers multiple time scales and coupled faults. Background Technology

[0002] Integrated Energy Systems (IES) achieve cascaded energy utilization through electro-thermal coupling and other methods, representing the future direction of energy development. Compared with single-energy systems, IES can fully utilize the complementary characteristics of different energy carriers, improving overall economic efficiency. However, ensuring the safe and stable operation of IES faces new technical challenges, among which multi-timescale characteristics and multi-energy flow coupling are particularly prominent.

[0003] Traditional safety assessments often overlook the fluid dynamics in district heating networks. In near-incompressible liquids, sudden valve operation can cause drastic changes in velocity and pressure, severely impacting pipelines. The resulting water hammer effect is a major cause of pipeline rupture. Because the characteristic timescale of water hammer lies between that of the power grid (milliseconds) and the heating network (hours), it is typically omitted in conventional assessments. Furthermore, in integrated energy systems, multi-energy coupling makes cascaded faults more insidious and far-reaching, allowing faults to propagate between subsystems. Heating network control equipment, such as valves and circulating pumps, typically requires a power supply; therefore, load shedding from the power grid can propagate disturbances to the heating network through the control layer.

[0004] Existing studies on the safety assessment of integrated energy systems have the following shortcomings: 1) The types of faults considered are usually focused on the components that directly perform energy conversion, with limited attention paid to the coupling effects originating from the control layer; 2) Many existing studies model the power grid as a fast subsystem and the heating network as a slow subsystem, thus ignoring hydraulic dynamics, even though water hammer may cause major system failures. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a multi-energy safety assessment method and device that considers multiple time scales and coupled faults. This invention captures the chain-like fault propagation in multi-energy coupled systems by explicitly modeling hydraulic transients and their resulting water hammer effect, and establishes a multi-level coupled fault classification system, thereby achieving a more comprehensive safety assessment.

[0006] A first aspect of this invention proposes a multi-energy security assessment method considering multiple time scales and coupled faults, comprising:

[0007] Establish intermediate timescale models and long timescale models of the integrated energy system, wherein the intermediate timescale model is a hydraulic transient model;

[0008] A safety assessment is performed on each fault scenario in the fault scenario set; wherein, the fault scenario is subjected to an N-1 safety scan using the long-time scale model considering coupled faults, and the system risk assessment index is calculated; when the system risk assessment index reflects that the fault scenario is a scenario that may lead to water hammer consequences, the overpressure value generated during the water hammer process is calculated using the intermediate time scale model.

[0009] Based on the safety assessment results for each failure scenario, the final safety assessment result of the integrated energy system is generated.

[0010] In a specific embodiment of the present invention, the intermediate timescale model construction process is as follows:

[0011] 1) Obtain the equations of motion and continuity equations for the hydraulic dynamic process:

[0012]

[0013]

[0014] In the formula, Represents gravitational acceleration. The pressure of the liquid inside the pipe. For liquid flow rate, The coefficient of friction of the pipe. The inner diameter of the pipe. The wave velocity of the pressure wave. This represents the displacement along the axial direction of the pipe. Indicates time;

[0015] 2) Based on the results of step 1), establish the expression for water hammer overpressure:

[0016]

[0017] In the formula, This represents the maximum overpressure value during the water hammer process. This represents the fluid velocity in the pipe after a water hammer occurs.

[0018] In one specific embodiment of the present invention, the long-time scale model is used to calculate the state of the heating network, specifically including:

[0019] Based on the connection relationship of the heating network, the pipeline flow rate, and the supply water temperature of the heat source node in the water supply network and the return water temperature of the load node in the return water network, the supply water temperature and return water temperature of each node in the heating network are calculated according to the flow conservation constraint, the temperature mixing constraint of the node and the temperature propagation loss constraint.

[0020] In one specific embodiment of the present invention, it further includes:

[0021] The process for constructing the temperature propagation loss constraint is as follows:

[0022] 1) Obtain the relationship between the outlet temperature and the inlet temperature of the supply and return water in the heating network under the condition of no heat loss:

[0023]

[0024]

[0025] In the formula, Let t be the outlet temperature of the water supply pipe under conditions of no heat loss. Let t be the outlet temperature of the return water pipe under the condition of no heat loss at time t; , and These are the coefficients calculated from parameters such as pipe flow rate, pipe diameter, and length at time t;

[0026] in:

[0027] The calculation expression is:

[0028]

[0029] In the formula, and Indicates pipeline exist Time and Mass flow rate at any given moment; and These are intermediate variables in the calculation process; The selected time interval is used for calculation; Ab is the pipe area. For the density of the liquid, This refers to the length of the pipe.

[0030] in:

[0031]

[0032]

[0033] In the formula, Indicates pipeline exist Quality flow rate at any given moment;

[0034] The calculation expression is:

[0035]

[0036] The calculation expression is:

[0037]

[0038] 2) Obtain the supply and return water outlet temperatures of the heating network after considering heat loss:

[0039]

[0040]

[0041] In the formula, Let t be the outlet temperature of the water supply pipe after considering heat loss; Let t be the outlet temperature of the return water pipe after considering heat loss; Let t be the outdoor temperature. Let be the heat transfer coefficient of pipe b, and c be the specific heat of the liquid.

[0042] In one specific embodiment of the present invention, considering coupling faults includes:

[0043] For an integrated energy system with electrothermal coupling, the coupling is divided into three layers: energy layer, logical layer, and geographical layer, where:

[0044] Energy layer coupling cascade events are cascades triggered within an integrated energy system when energy-related variables exceed a threshold and persist for a specified time, represented as:

[0045]

[0046] In the formula, This represents the comprehensive energy-related physical quantity at time t; For various fault types The threshold of the corresponding physical quantity; The moment the fault occurred; The set time period length;

[0047] Logic layer coupling cascade events refer to the interactions caused by the coupling relationships between the logic layers of various subsystems within an integrated energy system.

[0048] Geographic-layer coupling cascade events are interactions caused by the spatial proximity of subsystems within an integrated energy system.

[0049] In one specific embodiment of the present invention, the system risk assessment indicators include:

[0050] Line overload risk value index:

[0051]

[0052] In the formula, This indicates the probability of a corresponding line fault. This represents the line transmission power value. This represents the maximum transmission power allowed to pass through the line.

[0053] Indicators of risk value for exceeding temperature limits in heating networks:

[0054]

[0055] In the formula, This indicates the probability of a corresponding temperature-related fault occurring. Specific heat capacity of the liquid inside the pipe For the flow velocity in the pipe, For the temperature of the heating network nodes, This refers to the maximum allowable temperature value for a heating network node.

[0056] Loss of load risk index:

[0057]

[0058] In the formula, This represents the probability of load failure. This represents the power value corresponding to the load.

[0059] In one specific embodiment of the present invention, generating the final safety assessment result of the integrated energy system includes:

[0060] If no hydraulic transient calculations are performed under any of the fault scenarios, then no water hammer effect occurs in the integrated energy system. In particular, if the risk assessment indicators of each system calculated under each fault scenario do not exceed the corresponding safety threshold, then no risk is generated in the integrated energy system.

[0061] If the integrated energy system has performed hydraulic transient calculations under any fault scenario, the calculated water hammer overpressure value is compared with the pipeline safety pressure threshold. If the water hammer overpressure value under each fault scenario in which hydraulic transient calculations are performed does not exceed the limit, then the integrated energy system has not generated any risk.

[0062] A second aspect of the present invention provides a multi-energy security assessment system considering multiple time scales and coupled faults, comprising:

[0063] A multi-timescale model construction module is used to establish intermediate timescale models and long-timescale models of a comprehensive energy system, wherein the intermediate timescale model is a hydraulic transient model.

[0064] The scenario safety assessment module is used to perform a safety assessment on each fault scenario in the fault scenario set. Specifically, the fault scenario is subjected to an N-1 safety scan using the long-time scale model, taking into account coupled faults, and the system risk assessment index is calculated. When the system risk assessment index reflects that the fault scenario may lead to water hammer consequences, the overpressure value generated during the water hammer process is calculated using the intermediate time scale model.

[0065] The comprehensive assessment module is used to generate the final safety assessment result of the integrated energy system based on the safety assessment results of each failure scenario.

[0066] A third aspect of the present invention provides an electronic device comprising:

[0067] At least one processor; and a memory communicatively connected to said at least one processor;

[0068] The memory stores instructions that can be executed by the at least one processor, the instructions being configured to perform the aforementioned multi-energy security assessment method that considers multiple time scales and coupled faults.

[0069] A fourth aspect of the present invention provides a computer-readable storage medium storing computer instructions for causing the computer to execute the above-described multi-energy security assessment method considering multiple time scales and coupled faults.

[0070] Features and beneficial effects of the present invention:

[0071] 1) This invention establishes a multi-timescale model that includes intermediate timescale hydraulic transients, filling the gap in traditional assessments that ignore water hammer effects. It can effectively identify pipeline overpressure risks caused by rapid valve operation or pump shutdown, and avoid blind spots in safety assessments caused by ignoring hydraulic transients.

[0072] 2) This invention proposes a multi-dimensional coupled fault classification system that includes an energy layer, a logic layer, and a geographical layer. In particular, it reveals the hidden fault chain in which power grid faults trigger hydraulic shocks in heating networks through the logic layer (control power supply failure), thus expanding the dimensions of fault analysis for integrated energy systems.

[0073] 3) This invention can clearly depict the spatiotemporal propagation process of faults in multi-energy systems, providing a more accurate basis for the safety protection of integrated energy systems. Attached Figure Description

[0074] Figure 1 This is an overall flowchart of a multi-energy security assessment method considering multiple time scales and coupled faults, according to an embodiment of the present invention. Detailed Implementation

[0075] This invention proposes a multi-energy security assessment method and apparatus that considers multiple time scales and coupled faults, which will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0076] A first aspect of this invention proposes a multi-energy security assessment method considering multiple time scales and coupled faults, comprising:

[0077] Establish intermediate timescale models and long timescale models of the integrated energy system, wherein the intermediate timescale model is a hydraulic transient model;

[0078] A safety assessment is performed on each fault scenario in the fault scenario set; wherein, the fault scenario is subjected to an N-1 safety scan using the long-time scale model considering coupled faults, and the system risk assessment index is calculated; when the system risk assessment index reflects that the fault scenario is a scenario that may lead to water hammer consequences, the overpressure value generated during the water hammer process is calculated using the intermediate time scale model.

[0079] Based on the safety assessment results for each failure scenario, the final safety assessment result of the integrated energy system is generated.

[0080] In one specific embodiment of the present invention, the overall process of the multi-energy security assessment method considering multiple time scales and coupled faults is as follows: Figure 1 As shown, it includes the following steps:

[0081] 1) Establish a multi-timescale model of the integrated energy system.

[0082] Safety issues arising from a single fault in an integrated energy system can evolve across different time scales. These time scales can be categorized based on the duration of the dynamic process. This embodiment focuses on the hydraulic transient process at an intermediate time scale (seconds to minutes) and the long-term dynamic process of the heating network at an hour scale; the specific steps are as follows:

[0083] 1-1) Establish an intermediate timescale model, i.e., a hydraulic transient model; the specific steps are as follows:

[0084] 1-1-1) Obtain the equations of motion and continuity equations for the hydraulic dynamic process. This embodiment considers a single pipe with constant pipe material, wall thickness, and inner diameter:

[0085]

[0086]

[0087] In the formula, Represents gravitational acceleration. The pressure of the liquid inside the pipe. For liquid flow rate, The coefficient of friction of the pipe. The inner diameter of the pipe. This represents the wave speed of the pressure wave. This represents the displacement along the axial direction of the pipe. Indicates time.

[0088] 1-1-2) Establish the expression for water hammer overpressure.

[0089] In this embodiment, starting from the partial differential equations in step 1-1-1), simplification and derivation yield the following expression for calculating the overpressure caused by water hammer when the valve is closed:

[0090]

[0091] In the formula, This represents the maximum overpressure value during the water hammer process. This represents the fluid velocity in the pipeline after water hammer occurs. For water hammer caused by valve closure, it can be considered...

[0092] 1-2) Establish a long-term scale model.

[0093] In this embodiment, a long-term model is used to calculate the state of the heating network. There are many mature methods for calculating the state of the heating network. The basic approach is to use the network's connections, pipe flow rates, and the supply water temperatures of heat source nodes in the supply network and load nodes in the return water network as known quantities. Based on well-established constraints such as flow conservation, node temperature mixing, and temperature propagation loss, the supply and return water temperatures of each node in the entire heating network are calculated. The overall calculation result is used as the state calculation result of the heating network. This calculated heating network state will be used for subsequent routine evaluations and performance index calculations.

[0094] The above process is quite mature, but the expression for the temperature propagation loss constraint varies depending on the method used. In this embodiment, the historical temperature sequence of the first section of the pipe is used to calculate the temperature at the end of the pipe, which avoids the huge computational burden of the finite difference method while maintaining high accuracy.

[0095] Specifically, for a single pipe, we have:

[0096] 1-2-1) Obtain the relationship between the outlet temperature and inlet temperature of the supply and return water in the heating network under the condition of no heat loss:

[0097]

[0098]

[0099] In the formula, Let t be the outlet temperature of the water supply pipe under conditions of no heat loss. Let t be the outlet temperature of the return water pipe under the condition of no heat loss. , and These are coefficients calculated from parameters such as pipe flow rate, pipe diameter, and length at time t. Where:

[0100] The calculation expression is:

[0101]

[0102] In the formula, and Indicates pipeline exist Time and Mass flow rate at any given moment. and These are intermediate variables in the calculation process. The selected time interval is used for calculation. Ab is the pipe area. For the density of the liquid, This represents the length of the pipe.

[0103] in:

[0104]

[0105]

[0106] In the formula, Indicates pipeline exist The mass flow rate at any given time can be calculated from the historical flow rate of the pipeline.

[0107] The calculation expression is:

[0108]

[0109] The calculation expression is:

[0110]

[0111] 1-2-2) Obtain the supply and return water outlet temperatures of the heating network after considering heat loss:

[0112]

[0113]

[0114] In the formula, Let t be the outlet temperature of the water supply pipe after considering heat loss; Let t be the outlet temperature of the return water pipe after considering heat loss; Let t be the outdoor temperature. Let be the heat transfer coefficient of pipe b, and c be the specific heat of the liquid.

[0115] Based on the above formula, this method can be used to obtain the temperature propagation loss in the pipeline.

[0116] 2) Establish a set of fault scenarios.

[0117] In this embodiment, a set of fault scenarios to be considered during the comprehensive safety assessment is defined based on the specific circumstances of the electrothermal coupling system. Common fault types include: grid line interruption, grid generator failure and disconnection, electrothermal coupling CHP unit failure, and sudden changes in grid or heating network load. The set of fault scenarios is defined in conjunction with the specific circumstances of the example.

[0118] 3) Randomly select one fault scenario from the fault scenario set in step 2) as the current fault scenario, and conduct a comprehensive energy system safety assessment under the current fault scenario; the specific steps are as follows:

[0119] 3-1) Under the current fault scenario, perform a routine safety assessment and calculate performance metrics.

[0120] In this embodiment, the conventional safety assessment includes power grid flow calculation and heating network status calculation. The heating network status calculation requires the use of the long-term scale model established in steps 1-2) to perform an N-1 safety scan for the current fault scenario and calculate performance indicators, specifically including line overload risk value indicators, heating network temperature exceeding limit risk value indicators, and load shedding risk value indicators.

[0121] In this embodiment, for an electrothermal coupled integrated energy system, the performance indicators for measuring its safety are affected by the type of fault. This embodiment divides these couplings into three layers: energy layer, logical layer, and geographical layer. Different performance indicator calculation methods exist for coupling faults at different layers (the energy, logical, and geographical layers do not have a strict correspondence with the indicators; cascading events at these three layers may trigger different faults, which may require different indicators; that is, each layer may potentially use all three corresponding indicators). Wherein:

[0122] Energy layer coupled cascading events: The normal operation of an integrated energy system must meet safety constraints, such as branch power transmission limits, district heating node temperature limits, and unit output limits. These constraints are not strictly instantaneous; for example, line tripping requires overload to persist for a certain period. Therefore, energy layer faults can be viewed as cascading events triggered when energy-related variables exceed thresholds and persist for a specified time. Such coupled faults are represented as:

[0123]

[0124] In the formula, It can represent comprehensive energy-related physical quantities such as branch power flow, district heating node temperature, or unit output at time t. For various fault types The threshold value corresponding to the physical quantity. For example, for a branch power flow fault, This represents the integral value of branch power over time when the branch power exceeds the limit and accumulates to the point where it may cause an interruption. The moment the fault occurred; The set time period length is related to the actual situation of the system. Taking branch power flow as an example, its value can be selected according to the actual system, such as 15 seconds, 30 seconds, 15 minutes, etc.

[0125] Logic Layer Coupling Cascade Events: Interactions arising from the coupling relationships between the logic layers of various subsystems within an integrated energy system. Specifically, in an integrated energy system, coupling relationships exist between the various logic layers. When an abnormal action occurs in one layer, this logical relationship can continue to affect other systems. Coupling occurs not only at the energy layer but also at the logic (control) layer, having a substantial impact on operation. In a district heating system, control equipment (such as circulating pumps and valves) in the hydraulic circulation network controls hydraulic conditions and is typically used as electrical loads. Power system faults that trigger load shedding can cause these devices to fail, leading to hydraulic imbalance and interruption of heating, thus propagating the fault from the power grid to the hydraulic network, and then to the heating network.

[0126] Geographically Coupled Cascading Events: Geographic coupling refers to the interactions caused by the spatial proximity of subsystems within an integrated energy system. For example, when a district heating pipeline is close to power system assets, a rupture and leak in the hot water main may flood the surrounding area and cause failures in adjacent electrical equipment; subsequent power system failures, in turn, may trigger a chain of cascading events, extending the chain of failures. When constructing cascading failure chains, geographically proximate components can be modeled using the probability of triggering the next stage event based on proximity.

[0127] This embodiment establishes system risk assessment indicators for different fault types, including:

[0128] Line overload risk value index:

[0129]

[0130] In the formula, This indicates the probability of a corresponding line fault. This represents the line transmission power value. This represents the maximum transmission power allowed to pass through the line.

[0131] Indicators of risk value for exceeding temperature limits in heating networks:

[0132]

[0133] In the formula, This indicates the probability of a corresponding temperature-related fault occurring. Specific heat capacity of the liquid inside the pipe For the flow velocity in the pipe, For the temperature of the heating network nodes, This represents the maximum allowable temperature value for a heating network node.

[0134] Loss of load risk index:

[0135]

[0136] In the formula, This represents the probability of load failure. This represents the power value corresponding to the load.

[0137] 3-2) Based on the results of step 3-1), a judgment is made corresponding to the current fault scenario, wherein:

[0138] If the current fault scenario is identified as one that could lead to severe water hammer consequences, such as a power grid failure causing a loss of power to a critical valve or pump in the heating network, resulting in unplanned valve closure, then hydraulic transient calculations are performed. The intermediate timescale model established in step 1-1) is used to calculate the overpressure value generated during the water hammer process. Otherwise, hydraulic transient calculations are not required in the current fault scenario.

[0139] 4) Remove the fault scenarios selected in step 3) from the fault scenario set in step 2), and then determine:

[0140] If the fault scenario set is not empty, return to step 3) and perform a safety assessment for the next fault scenario.

[0141] If the fault scenario set is empty, proceed to step 5).

[0142] 5) Based on the safety assessment results under all failure scenarios, generate the final safety assessment results of the integrated energy system.

[0143] If no hydraulic transient calculations are performed in any of the fault scenarios, indicating that the integrated energy system has not experienced water hammer, then the system safety is determined based on the system risk assessment indicators calculated in step 3-1) under each fault scenario. Specifically, a safety threshold is set for each indicator based on the specific circumstances of the system instance. If none of the calculated system risk assessment indicators for each scenario exceed the corresponding safety threshold, the integrated energy system is considered to be free of risk. If any indicator exceeds the corresponding safety threshold in some scenarios, it is recorded as important information regarding the overall system safety risk assessment.

[0144] If the integrated energy system has performed hydraulic transient calculations under any fault scenario, the calculated water hammer overpressure value is compared with the pipeline safety pressure threshold. If the water hammer overpressure value under each fault scenario in which hydraulic transient calculations are performed does not exceed the limit, the integrated energy system is considered to have no risk; otherwise, the scenarios in which the limit is exceeded are recorded.

[0145] In summary, the overall security risk assessment of the system can be obtained.

[0146] Furthermore, in this embodiment, based on the overall security risk assessment of the system, targeted system security enhancement measures can be implemented. For example, for scenarios where risk indicators exceed the threshold, security reinforcement measures can be implemented, including increasing line capacity and adding temporary heating and insulation equipment for loads where the heating network temperature exceeds the limit.

[0147] To achieve the above embodiments, a second aspect of the present invention proposes a multi-energy security assessment system considering multiple time scales and coupled faults, comprising:

[0148] A multi-timescale model construction module is used to establish intermediate timescale models and long-timescale models of a comprehensive energy system, wherein the intermediate timescale model is a hydraulic transient model.

[0149] The scenario safety assessment module is used to perform a safety assessment on each fault scenario in the fault scenario set. Specifically, the fault scenario is subjected to an N-1 safety scan using the long-time scale model, taking into account coupled faults, and the system risk assessment index is calculated. When the system risk assessment index reflects that the fault scenario may lead to water hammer consequences, the overpressure value generated during the water hammer process is calculated using the intermediate time scale model.

[0150] The comprehensive assessment module is used to generate the final safety assessment result of the integrated energy system based on the safety assessment results of each failure scenario.

[0151] In a specific embodiment of the present invention, the intermediate timescale model construction process is as follows:

[0152] 1) Obtain the equations of motion and continuity equations for the hydraulic dynamic process:

[0153]

[0154]

[0155] In the formula, Represents gravitational acceleration. The pressure of the liquid inside the pipe. For liquid flow rate, The coefficient of friction of the pipe. The inner diameter of the pipe. The wave velocity of the pressure wave. This represents the displacement along the axial direction of the pipe. Indicates time;

[0156] 2) Based on the results of step 1), establish the expression for water hammer overpressure:

[0157]

[0158] In the formula, This represents the maximum overpressure value during the water hammer process. This represents the fluid velocity in the pipe after a water hammer occurs.

[0159] In one specific embodiment of the present invention, the long-time scale model is used to calculate the state of the heating network, specifically including:

[0160] Based on the connection relationship of the heating network, the pipeline flow rate, and the supply water temperature of the heat source node in the water supply network and the return water temperature of the load node in the return water network, the supply water temperature and return water temperature of each node in the heating network are calculated according to the flow conservation constraint, the temperature mixing constraint of the node and the temperature propagation loss constraint.

[0161] In one specific embodiment of the present invention, it further includes:

[0162] The process for constructing the temperature propagation loss constraint is as follows:

[0163] 1) Obtain the relationship between the outlet temperature and the inlet temperature of the supply and return water in the heating network under the condition of no heat loss:

[0164]

[0165]

[0166] In the formula, Let t be the outlet temperature of the water supply pipe under conditions of no heat loss. Let t be the outlet temperature of the return water pipe under the condition of no heat loss at time t; , and These are the coefficients calculated from parameters such as pipe flow rate, pipe diameter, and length at time t;

[0167] in:

[0168] The calculation expression is:

[0169]

[0170] In the formula, and Indicates pipeline exist Time and Mass flow rate at any given moment; and These are intermediate variables in the calculation process; The selected time interval is used for calculation; Ab is the pipe area. For the density of the liquid, This refers to the length of the pipe.

[0171] in:

[0172]

[0173]

[0174] In the formula, Indicates pipeline exist Quality flow rate at any given moment;

[0175] The calculation expression is:

[0176]

[0177] The calculation expression is:

[0178]

[0179] 2) Obtain the supply and return water outlet temperatures of the heating network after considering heat loss:

[0180]

[0181]

[0182] In the formula, Let t be the outlet temperature of the water supply pipe after considering heat loss; Let t be the outlet temperature of the return water pipe after considering heat loss; Let t be the outdoor temperature. Let be the heat transfer coefficient of pipe b, and c be the specific heat of the liquid.

[0183] In one specific embodiment of the present invention, considering coupling faults includes:

[0184] For an integrated energy system with electrothermal coupling, the coupling is divided into three layers: energy layer, logical layer, and geographical layer, where:

[0185] Energy layer coupling cascade events are cascades triggered within an integrated energy system when energy-related variables exceed a threshold and persist for a specified time, represented as:

[0186]

[0187] In the formula, This represents the comprehensive energy-related physical quantity at time t; For various fault types The threshold of the corresponding physical quantity; The moment the fault occurred; The set time period length;

[0188] Logic layer coupling cascade events refer to the interactions caused by the coupling relationships between the logic layers of various subsystems within an integrated energy system.

[0189] Geographic-layer coupling cascade events are interactions caused by the spatial proximity of subsystems within an integrated energy system.

[0190] In one specific embodiment of the present invention, the system risk assessment indicators include:

[0191] Line overload risk value index:

[0192]

[0193] In the formula, This indicates the probability of a corresponding line fault. This represents the line transmission power value. This represents the maximum transmission power allowed to pass through the line.

[0194] Indicators of risk value for exceeding temperature limits in heating networks:

[0195]

[0196] In the formula, This indicates the probability of a corresponding temperature-related fault occurring. Specific heat capacity of the liquid inside the pipe For the flow velocity in the pipe, For the temperature of the heating network nodes, This refers to the maximum allowable temperature value for a heating network node.

[0197] Loss of load risk index:

[0198]

[0199] In the formula, This represents the probability of load failure. This represents the power value corresponding to the load.

[0200] In one specific embodiment of the present invention, generating the final safety assessment result of the integrated energy system includes:

[0201] If no hydraulic transient calculations are performed under any of the fault scenarios, then no water hammer effect occurs in the integrated energy system. In particular, if the risk assessment indicators of each system calculated under each fault scenario do not exceed the corresponding safety threshold, then no risk is generated in the integrated energy system.

[0202] If the integrated energy system has performed hydraulic transient calculations under any fault scenario, the calculated water hammer overpressure value is compared with the pipeline safety pressure threshold. If the water hammer overpressure value under each fault scenario in which hydraulic transient calculations are performed does not exceed the limit, then the integrated energy system has not generated any risk.

[0203] This enables the explicit modeling of hydraulic transients and their resulting water hammer effect, capturing chain-like fault propagation in multi-energy coupled systems, establishing a multi-level coupled fault classification system, and thus achieving a more comprehensive safety assessment.

[0204] To implement the above embodiments, a third aspect of the present invention provides an electronic device, comprising:

[0205] At least one processor; and a memory communicatively connected to said at least one processor;

[0206] The memory stores instructions that can be executed by the at least one processor, the instructions being configured to perform the aforementioned multi-energy security assessment method that considers multiple time scales and coupled faults.

[0207] To implement the above embodiments, a fourth aspect of the present invention provides a computer-readable storage medium storing computer instructions for causing the computer to execute the above-described multi-energy security assessment method considering multiple time scales and coupled faults.

[0208] It should be noted that the computer-readable medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0209] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform a multi-energy security assessment method considering multiple time scales and coupled faults according to the above embodiments.

[0210] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0211] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0212] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0213] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0214] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0215] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0216] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0217] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0218] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A multi-energy security assessment method considering multiple time scales and coupled faults, characterized in that, include: Establish intermediate timescale models and long timescale models of the integrated energy system, wherein the intermediate timescale model is a hydraulic transient model; A safety assessment is performed on each fault scenario in the fault scenario set; wherein, the fault scenario is subjected to an N-1 safety scan using the long-time scale model considering coupled faults, and the system risk assessment index is calculated; when the system risk assessment index reflects that the fault scenario is a scenario that may lead to water hammer consequences, the overpressure value generated during the water hammer process is calculated using the intermediate time scale model. Based on the safety assessment results for each failure scenario, the final safety assessment result of the integrated energy system is generated.

2. The method according to claim 1, characterized in that, The process of constructing the intermediate timescale model is as follows: 1) Obtain the equations of motion and continuity equations for the hydraulic dynamic process: In the formula, Represents gravitational acceleration. The pressure of the liquid inside the pipe. For liquid flow rate, The coefficient of friction of the pipe. The inner diameter of the pipe. The wave velocity of the pressure wave. This represents the displacement along the axial direction of the pipe. Indicates time; 2) Based on the results of step 1), establish the expression for water hammer overpressure: In the formula, This represents the maximum overpressure value during the water hammer process. This represents the fluid velocity in the pipe after a water hammer occurs.

3. The method according to claim 1, characterized in that, The long-term model is used to calculate the state of the heating network, specifically including: Based on the connection relationship of the heating network, the pipeline flow rate, and the supply water temperature of the heat source node in the water supply network and the return water temperature of the load node in the return water network, the supply water temperature and return water temperature of each node in the heating network are calculated according to the flow conservation constraint, the temperature mixing constraint of the node and the temperature propagation loss constraint.

4. The method according to claim 3, characterized in that, Also includes: The process for constructing the temperature propagation loss constraint is as follows: 1) Obtain the relationship between the outlet temperature and the inlet temperature of the supply and return water in the heating network under the condition of no heat loss: In the formula, Let t be the outlet temperature of the water supply pipe under conditions of no heat loss. Let t be the outlet temperature of the return water pipe under the condition of no heat loss at time t; , and These are the coefficients calculated from parameters such as pipe flow rate, pipe diameter, and length at time t; in: The calculation expression is: In the formula, and Indicates pipeline exist Time and Mass flow rate at any given moment; and These are intermediate variables in the calculation process; The selected time interval is used for calculation; Ab is the pipe area. For the density of the liquid, This refers to the length of the pipe. in: In the formula, Indicates pipeline exist Quality flow rate at any given moment; The calculation expression is: The calculation expression is: 2) Obtain the supply and return water outlet temperatures of the heating network after considering heat loss: In the formula, Let t be the outlet temperature of the water supply pipe after considering heat loss; Let t be the outlet temperature of the return water pipe after considering heat loss; Let t be the outdoor temperature. Let be the heat transfer coefficient of pipe b, and c be the specific heat of the liquid.

5. The method according to claim 3, characterized in that, The consideration of coupled faults includes: For an integrated energy system with electrothermal coupling, the coupling is divided into three layers: energy layer, logical layer, and geographical layer, where: Energy layer coupling cascade events are cascades triggered within an integrated energy system when energy-related variables exceed a threshold and persist for a specified time, represented as: In the formula, This represents the comprehensive energy-related physical quantity at time t; For various fault types The threshold of the corresponding physical quantity; The moment the fault occurred; The set time period length; Logic layer coupling cascade events refer to the interactions caused by the coupling relationships between the logic layers of various subsystems within an integrated energy system. Geographic-layer coupling cascade events are interactions caused by the spatial proximity of subsystems within an integrated energy system.

6. The method according to claim 5, characterized in that, The system risk assessment indicators include: Line overload risk value index: In the formula, This indicates the probability of a corresponding line fault. This represents the line transmission power value. This represents the maximum transmission power allowed to pass through the line. Indicators of risk value for exceeding temperature limits in heating networks: In the formula, This indicates the probability of a corresponding temperature-related fault occurring. Specific heat capacity of the liquid inside the pipe For the flow velocity in the pipe, For the temperature of the heating network nodes, This refers to the maximum allowable temperature value for a heating network node. Loss of load risk index: In the formula, This represents the probability of load failure. This represents the power value corresponding to the load.

7. The method according to claim 6, characterized in that, The generation of the final safety assessment result of the integrated energy system includes: If no hydraulic transient calculations are performed under any of the fault scenarios, then no water hammer effect occurs in the integrated energy system. In particular, if the risk assessment indicators of each system calculated under each fault scenario do not exceed the corresponding safety threshold, then no risk is generated in the integrated energy system. If the integrated energy system has performed hydraulic transient calculations under any fault scenario, the calculated water hammer overpressure value is compared with the pipeline safety pressure threshold. If the water hammer overpressure value under each fault scenario in which hydraulic transient calculations are performed does not exceed the limit, then the integrated energy system has not generated any risk.

8. A multi-energy security assessment system considering multiple time scales and coupled faults, characterized in that, include: A multi-timescale model construction module is used to establish intermediate timescale models and long-timescale models of a comprehensive energy system, wherein the intermediate timescale model is a hydraulic transient model. The scenario safety assessment module is used to perform a safety assessment on each fault scenario in the fault scenario set. Specifically, the fault scenario is subjected to an N-1 safety scan using the long-time scale model, taking into account coupled faults, and the system risk assessment index is calculated. When the system risk assessment index reflects that the fault scenario may lead to water hammer consequences, the overpressure value generated during the water hammer process is calculated using the intermediate time scale model. The comprehensive assessment module is used to generate the final safety assessment result of the integrated energy system based on the safety assessment results of each failure scenario.

9. An electronic device, characterized in that, include: At least one processor; And, a memory communicatively connected to the at least one processor; The memory stores instructions executable by the at least one processor, the instructions being configured to perform the method described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method according to any one of claims 1-7.

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