A fault response and recovery method for an electric-thermal integrated energy information-physical system

Abstract

The present invention relates to the technical field of electric-thermal integrated energy information-physical system, and discloses a fault response and recovery method for an electric-thermal integrated energy information-physical system. The multiple coupling relationships among electric power, thermal power and information systems are fully considered, the impact of the information layer on the physical layer in the fault response phase is modeled, and the fault propagation and response characteristics simulation in a multi-system deep coupling scenario is realized. The proposed resilience recovery model is also based on the ETIECPS framework, which comprehensively considers the impact of the information layer on the physical layer in the recovery phase, and realizes a rapid response and optimized fault recovery process through the collaborative recovery mechanism of the information-physical system, thereby improving the recovery efficiency and overall stability of the system under multiple attack scenarios.

Description

Technical Field

[0001] The present invention relates to the technical field of electric-thermal integrated energy information-physical system, and specifically to a fault response and recovery method for an electric-thermal integrated energy information-physical system. Background Art

[0002] With the continuous growth of global energy demand and the rapid development of renewable energy, traditional energy systems are facing many challenges. The establishment of an integrated energy system with multi-energy complementarity and multi-source coordination has received more and more attention. The traditional power system has evolved from a single power network to a system that integrates multiple energy forms (such as electricity and thermal energy). At the same time, with the deep integration of information technology, an electrical and thermal integrated energy cyber-physical system (ETIECPS) has been formed. This system not only combines the operation of physical equipment and the control of information technology, but also emphasizes the coupling and coordination of multiple energy forms such as electricity and thermal energy.

[0003] The electric-thermal integrated energy cyber-physical system (ETIECPS) is a typical integrated energy system that can achieve the optimal configuration and efficient utilization of multiple energy sources such as electricity and heat through intelligent scheduling and information processing. Through the collaborative work of sensors, data acquisition equipment, and control equipment, the energy flow and information flow in the system are closely intertwined, supporting the stability and flexibility of the energy system. However, with the complexity of the system and the interweaving of multiple energy flows, ETIECPS also brings more risks and challenges.

[0004] As ETIECPS develops, its risks are also increasing. The coupling relationship between the subsystems means that a fault or disturbance in one subsystem may spread quickly to other subsystems through the information network, causing a chain reaction. Many historical events have shown that the spread of faults or disturbances becomes faster due to the system coupling relationship, and the risks faced by the system also increase, which fully demonstrates the complexity and fragility of ETIECPS. When dealing with system failures, the traditional single system management method is no longer perfect.

[0005] Therefore, it is particularly important to study the fault response and recovery strategies of ETIECPS. Existing research is often limited to the risk control of a single energy system, such as only handling faults in power or thermal systems. There is a lack of research on the coordinated response to faults in multiple energy systems, especially in the electric-thermal integrated energy system where information and physics are deeply coupled. In ETIECPS, the high correlation between various energy systems and information systems makes it possible for faults to spread rapidly across systems. Therefore, studying how to coordinate the coordinated response and recovery strategies of multiple systems after a fault occurs to ensure that the system can be restored to a stable operating state in the shortest time has become a key issue that needs to be solved in the current technical field.

[0006] Resilience refers to the ability of a system to maintain core functions, respond quickly and resume normal operation when faced with low-probability but high-impact events. In energy systems, resilience is particularly important because it directly determines the stability and reliability of the system in emergencies. With the integration of multiple energy forms and the in-depth application of information networks, modern energy systems have increasingly higher requirements for resilience when dealing with complex environments and potential threats.

[0007] Existing research in the field of resilience mainly focuses on fault response and recovery of traditional power systems, while research on integrated energy systems and cyber-physical systems is relatively rare, and research specifically considering ETIECPS is even more limited. Research on fault response and recovery methods often focuses on the physical level of a single system, making it difficult to cope with complex fault scenarios under the deep coupling of multiple energy flows and information networks.

[0008] In traditional power systems, there are already a large number of fault response and recovery methods for extreme weather conditions. These methods usually improve the resilience of the system through disaster prediction and risk modeling, combined with network reconstruction, optimized scheduling strategies, and rapid repair of key components. With the deep coupling of multiple energy flows such as electricity, heat, and gas in integrated energy systems, the complexity of fault response and recovery has increased significantly. Fault response measures have been upgraded from a single energy processing mode to a multi-energy collaborative approach, involving linkage between multiple systems. It is necessary to conduct multi-energy risk assessment and fault simulation, optimize the scheduling plan by comprehensively considering the coupling between multiple energy flows, and formulate a coordinated recovery strategy. Efficient resource allocation and scheduling are required between different energy flows to ensure the overall resilience of the system.

[0009] With the development of cyber-physical system (CPS) technology, the complexity of fault response has been further improved. The method of improving system resilience not only needs to deal with physical-level faults, but also needs to consider information-level threats, such as information attacks and communication failures. To this end, the resilience improvement of CPS systems is usually achieved through a variety of means, including real-time detection and defense of information attacks, reasonable allocation of defense resources, and optimization of network routing to ensure the communication security and stability of the system. In addition, CPS systems also emphasize the coordinated protection of information and physical systems, and maximize the system's adaptive ability and recovery efficiency in the event of a fault by comprehensively using data analysis, intelligent scheduling and system recovery strategies. However, the research on CPS systems mainly focuses on the coupling of power systems and information systems, and the attacks considered are often concentrated at the information level, failing to fully consider the coordinated fault recovery of multiple systems under the conditions of dual coupling of information and physics.

[0010] When the power system is attacked physically, the fault may be transmitted to the thermal system through the thermoelectric coupling device, further causing abnormal operation of the thermal system. At the same time, the fault information is also transmitted to the information system through the cyber-physical coupling channel, causing the control function of the information system to be disturbed or fail, thereby aggravating the spread of the fault and possibly causing cascading failures. When the information system is attacked, the fault effect will be transmitted back to the physical system through the cyber-physical coupling channel, causing control failure or abnormality of the power and thermal systems. When facing the coordinated attack of information and physics, the system's fault propagation speed and impact range will increase significantly, and the destructiveness of the fault will be more serious. However, the multi-coupling structure not only increases the risk of the system, but also provides the possibility of improving the resilience of the system. Through reasonable coordination and control, the information system can achieve efficient deployment between the power system and the thermal system, enhance the synergy between the subsystems, ensure that the system can respond and recover faster and more effectively when facing faults, and thus improve the resilience of the entire system. Therefore, it is of great significance to establish a fault response and recovery model of ETIECPS to cope with the complex situations it faces.

[0011] Although existing research has provided relatively mature fault response and recovery methods for traditional power systems, their application in integrated energy systems and cyber-physical coupling systems is still insufficient:

[0012] First, as the coupling of multiple energy flow systems continues to deepen and the interaction of cyber-physical systems becomes increasingly complex, fault response and recovery need to be considered at the level of the entire integrated energy cyber-physical system. This means that when modeling, it is necessary not only to consider the independent operation of each subsystem, but also to explore the synergy between multiple systems in depth to ensure that the stability of the overall system can be restored quickly and effectively.

[0013] Second, in traditional energy systems, existing research focuses on fault responses at the physical level, such as natural disasters. In the research of CPS systems, most of the focus is on attacks at the information level. In these systems, the combined effects of information attacks and physical attacks are often not fully explored. For ETIECPS, fault response and recovery need to comprehensively consider multiple forms of attacks, including information attacks, physical attacks, and information-physical coupling attacks, in order to improve the overall resilience of the system and its ability to cope with complex scenarios. Therefore, how to effectively integrate fault response and recovery strategies between multiple energy flows and multiple systems in ETIECPS, especially to cope with the challenges of cross-domain fault propagation, is the key to future resilience research.

[0014] In summary, current technologies mostly focus on fault handling of a single system (such as the power system), and fail to fully consider the deep coupling relationship between electrical, thermal, and information systems, resulting in the inability to reflect the coordinated response of each system when a fault occurs. The purpose of this invention is to establish a comprehensive fault response and recovery method suitable for ETIECPS, so that in the context of multi-system coupling, coordinated response and coordinated resilience recovery can be achieved more effectively.

[0015] Existing technologies mainly deal with single physical layer attacks (such as natural disasters), but there is little discussion on the impact of information attacks, physical attacks and their synergy. This limitation makes the system more vulnerable when facing multi-level and coordinated attacks. Summary of the invention

[0016] In view of the above problems, the purpose of the present invention is to provide a fault response and recovery method for an electric-thermal integrated energy information-physical system, so that in the context of multi-system coupling, coordinated response and coordinated resilience recovery can be achieved more effectively; Binhai introduces the scenarios of information attack, physical attack and information-physical coordinated attack into the fault response and recovery model to ensure that the system can fully characterize the overall response of the system under complex attack modes. The technical solution is as follows:

[0017] A method for fault response and recovery of an electric-thermal integrated energy information-physical system, comprising the following steps:

[0018] Step 1: Establish an electric-thermal integrated energy information-physical system model:

[0019] At the physical level, the power system and thermal system are modeled, and the coupled system of the two is modeled. Through the modeling at the physical level, the flow path and interaction of energy in the physical system are established; at the information level, the corresponding information system is established for the power system and thermal system; at the information-physical coupling level, the synergistic relationship between information and physics is modeled to describe the interaction between the two;

[0020] Step 2: Establish a fault response optimization model:

[0021] Based on the electric-thermal integrated energy information-physical system model in step 1, consider the multi-level impacts under multiple fault scenarios, including the impact of load loss in the physical system on the information system, and the impact of information system failure on the physical system, and establish a fault response optimization model with the optimization goal of minimizing physical layer load loss and information layer damage;

[0022] Step 3: Jointly optimize fault response and recovery:

[0023] Based on the fault response results of the fault response optimization model, the fault response and recovery of the electric-thermal integrated energy information-physical system are jointly optimized: on the basis of the fault response optimization model, with minimizing the load loss of the physical system, minimizing the damage to the information system and shortening the fault recovery time as the optimization goals, a joint optimization model of fault response and recovery is established to reflect the response and recovery of the system to various faults; under the joint optimization model of fault response and recovery, fault response and recovery are performed on the input multiple fault scenarios, and finally the resilience curves of each system are output.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention fully integrates the coupling relationship between power, thermal and information systems in the ETIECPS architecture, and can achieve efficient coordinated response to the situation where multiple systems suffer from faults at the same time; in the fault response and recovery process, the present invention can accurately reflect the complexity of multi-system coupling and fully capture the mutual influence between the systems, thereby improving the overall recovery efficiency and response accuracy of the system.

[0026] 2. The present invention breaks through the limitation of traditional methods of only responding to single physical attacks, and can effectively respond to information attacks, physical attacks, and information-physical coordinated attacks. By fully considering the response of each system under multiple fault modes, the present invention can accurately reflect the behavior and response of the coupled system under complex and diversified attacks, so that the system's anti-interference and coupling characteristics under different attack scenarios can be fully reflected. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of the ETIECPS fault response and recovery method of the present invention.

[0028] Figure 2 It is a schematic diagram of the ETIECPS structure of the present invention.

[0029] Figure 3 This is the ETIECPS toughness curve of the present invention.

[0030] Figure 4 This is a schematic diagram of a calculation example of the present invention.

[0031] Figure 5It is a power load resilience curve diagram of various schemes of the present invention.

[0032] Figure 6 It is a thermal load toughness curve diagram of various schemes of the present invention.

[0033] Figure 7 This is a toughness curve diagram of the number of information nodes in various solutions of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention proposes a fault response and recovery method for an electrothermal integrated energy cyber-physical system (ETIECPS), the overall process of which is as follows: Figure 1 As shown in the figure, this method extends the fault response and recovery methods of single energy systems and cyber-physical systems to ETIECPS, taking into full account the complexity of multiple couplings of the system and the diverse attack modes. The resilience research of the present invention covers the fault response and recovery of cyber-physical systems under the interaction of multiple energy types, and specifically includes the following steps:

[0036] Step 1: Establish the system model of ETIECPS:

[0037] At the physical level, the power system and thermal system are modeled, and the coupled system of the two is modeled. Through the modeling at the physical level, the flow path and interaction of energy in the physical system are established. At the information level, the corresponding information system is established for the power system and thermal system. For the information-physical coupling level, the synergistic relationship between information and physics is modeled to describe the interaction between the two. Finally, the system modeling of ETIECPS is completed, and the coupling relationship and synergistic relationship between electricity, heat and information are accurately described.

[0038] The structural diagram of ETIECPS of the present invention is as follows Figure 2 As shown in the figure. ETIECPS consists of an information layer and a physical layer. The physical layer includes the power system, the thermal system and the coupling elements between the two, and the information layer includes the control center and information elements. The information layer collects data from the physical layer in real time through sensors and communication channels, and transmits control signals to the physical layer to monitor and control it. The power system and the thermal system are closely connected through coupling devices such as combined heat and power (CHP) and electric boilers (EB), forming an efficient coupling system.

[0039] (1) Coupling relationship between cyber-physical systems:

[0040] Firstly, the physical elements such as power source, heat source, load and coupling elements in the physical system are abstracted as nodes, and the information elements with monitoring, control and communication functions are also abstracted as nodes.

[0041] The power system model is expressed as ,in, and They represent the node set and line set in the power system respectively;

[0042] The thermal system model is expressed as ,in, and They represent the node set and line set of the thermal system respectively;

[0043] The information system model is represented as ,in, and They are information system nodes and line collections respectively.

[0044] Based on complex network theory, the information-physical correlation matrix is ​​used to describe the coupling relationship between information and physics. The nodes of the information system correspond one-to-one to the nodes of the physical system. The information system has a measurement and control function on the physical system, and the physical system has an energy supply function for the information system, as shown in formula (1):

[0045] (1);

[0046] in, is the cyber-physical correlation matrix; is the information connection matrix, which is expressed in detail as formula (2), and its elements The value is formula (3); is the physical connection matrix, which is expressed in detail as formula (4), and its elements The value is formula (5); Represents the measurement and control relationship between the information system and the physical system. Its elements If it is 1, it means that the information layer has a measurement and control function on the physical layer, and if it is 0, it means that there is no measurement and control function. Represents the energy supply relationship between physical nodes and information nodes. Its elements If it is 1, it means that the physical node has an energy supply relationship with the information node. The energy of the power information node is provided by the corresponding power node, and the energy of the information node in the thermal system is provided by the nearest power node.

[0047] (2);

[0048] (3);

[0049] In the formula, For the power information connection matrix, It is the thermal information connection matrix.

[0050] (4);

[0051] (5);

[0052] In the formula, is the power physical connection matrix, is the thermodynamic physics connection matrix.

[0053] (2) Information system model:

[0054] The working state of the information node is determined by two key factors: one is the power supply state of the information node, and the other is the communication connection state between the information node and the information center. These two conditions must be met at the same time for the information node to maintain normal operation. The information node maintains a communication connection with the source end, which means that there must be communication traffic between the information node and the information center. The model is established as follows.

[0055] The working status of the information node is expressed as:

[0056] (6);

[0057] In the formula, Information Node exist When both power supply and communication are in normal state, the information node works normally.

[0058] The working status of the information line is expressed as:

[0059] (7);

[0060] In the formula, For information lines exist Working status at all times. When there is communication traffic, its value is 1. .

[0061] Information equipment needs to be supplied with electricity for normal operation. If the information node is not equipped with UPS, the information node may fail due to insufficient energy supply of the physical node. The energy supply status of the information node is expressed as:

[0062] (8);

[0063] In the formula, Information Node exist Energy supply status at all times; and For power nodes The actual power load and the demand power load, is the energy coupling coefficient, which reflects the coupling degree between the information layer and the physical layer. The larger the value, the deeper the coupling between the information layer and the physical layer. With information node The relationship between Decide.

[0064] The node communication flow balance is expressed as:

[0065] (9);

[0066] In the formula, is the information node-source node association matrix; is the information node-information line association matrix; for The information flow matrix of the source end at each moment; for The working status matrix of the moment information node; for Communication flow matrix of information lines at each moment.

[0067] The line communication flow must be within the supply range and is subject to the working status of the information nodes it connects:

[0068] (10);

[0069] (11);

[0070] (12);

[0071] (13);

[0072] In the formula, is the maximum value of line communication flow; is the number of information lines, for The working status of the information node at all times; for Time information line communication flow.

[0073] The amount of information at the source must be within the supply range:

[0074] (14);

[0075] The working status of the information node is constrained by the power supply status:

[0076] (15);

[0077] (3) Power system model:

[0078] The power system model adopts the commonly used DC power flow model, and the power balance relationship is as follows:

[0079] (16);

[0080] In the formula, for The power matrix of the moment generation, ; for The power matrix of combined heat and power generation at all times; for Load power matrix at the moment; for The electric boiler load power matrix at the moment; for The branch power matrix at time , ; , , , and They are the power node-generation node association matrix, the power node-cogeneration node association matrix, the power node-load node association matrix, the power node-electric boiler node association matrix and the power node-branch association matrix.

[0081] Branch flow relationship:

[0082] (17);

[0083] In the formula, For power lines exist The branch power at the moment; For power nodes The voltage phase angle; For power nodes The voltage phase angle; For power lines impedance.

[0084] Runtime safety constraints:

[0085] (18);

[0086] (19);

[0087] (20);

[0088] In the formula, is the upper limit of line power; and Power Node The upper and lower limits of the voltage phase angle; For power nodes The generator at The power generation at the moment; and Power Node The upper and lower limits of the generator power generation capacity.

[0089] (4) Thermal system model:

[0090] The present invention uses the electrical analogy thermal power representation method to establish a thermal system model. The generalized circuit model of the heat network is a double-layer network formed by coupling the water supply network and the return water network. The water supply network has a higher temperature and transfers heat from the heat source to the heat load. After the load consumes the heat, the working fluid with a lower temperature enters the return water network, returns to the heat source, is heated again and enters the water supply network. The water supply pipe and the return water pipe are generally made of the same material and are arranged in parallel. In the study, it can be considered that the pipe parameters of the two are the same and the topological structure is symmetrical.

[0091] The relationship between heat source output and heat demand is as follows: heat source output is related to both the water supply network and the return water network.

[0092] (twenty one);

[0093] In the formula, for The heat source output matrix at each moment, ; for Thermal load power matrix at each moment, ; for The heat generation power matrix entering the water supply network at all times is related to the temperature of the heating node and is controlled by the operator; and are the heat transfer coupling matrices of the heating network and the heat recovery network, respectively, which represent the impact of a certain node temperature change on the temperatures of other nodes in the network; is the identity matrix.

[0094] (5) Coupling element model:

[0095] The coupling element in the present invention includes a cogeneration unit and an electric boiler, which is described by its operating efficiency conversion equation:

[0096] (twenty two);

[0097] (twenty three);

[0098] In the formula, for The thermal output power matrix of CHP at each moment, ; is the conversion efficiency of cogeneration, and They are the upper and lower limits of combined heat and power generation power, respectively.

[0099] (twenty four);

[0100] (25);

[0101] In the formula, for The thermal power matrix of the electric boiler heat output at each moment, ; is the conversion efficiency of the electric boiler, and They are the upper and lower limits of the electric boiler load power respectively.

[0102] Step 2: Establish a fault response optimization model:

[0103] Based on the established ETIECPS system model, a fault response optimization model is further established. This model takes into account the multi-level impacts of multiple fault scenarios, including the impact of load loss in the physical system on the information system, and the impact of information system failure on the physical system. The optimization model is established with the optimization goal of minimizing the load loss at the physical layer and the damage at the information layer, reflecting the system's response to multiple faults.

[0104] Since power lines are exposed to the air and vulnerable to physical attacks, while thermal pipelines are usually deployed underground and are physically more hidden, this model mainly considers the failure of the power system and assumes that the physical structure of the thermal system is not affected.

[0105] The toughness curve of the physical layer is as follows Figure 3 As shown, represents the time corresponding to the power system resilience curve, represents the time corresponding to the toughness curve of the thermal system, where . For the initial performance of electricity; Minimum performance for electricity; is the thermal initial performance; For ETIECPS, the fault response phase is ~ The fault recovery phase is ~ stage.

[0106] First, the model analyzes the impact of the information system on the power system and thermal system during the fault response stage. For the power system, when the measurement and control function in the information system fails, although the generator set of the power system can still cope with small-amplitude and short-cycle load fluctuations through a single frequency regulation, the failure of the automatic generation control (AGC) function will greatly limit its regulation sensitivity. At this time, the generator set can only make limited adjustments near its output state in the previous stage, and it is difficult to cope with large load changes. Therefore, if there is a load change beyond the regulation range, the control center cannot adjust in real time, resulting in a reduction in the safety margin of the system. To simplify the processing, after the unbalanced power of the system (specifically what system) is absorbed, the model (specifically what system) simplifies the process to cutting off the uncontrollable unit to achieve system power balance and frequency recovery.

[0107] (26);

[0108] In the formula, For power nodes The generator at The power generation at the moment, the power information node ( ) and its physical power generation node ( ) corresponding to.

[0109] For thermal systems, when an information node fails, the information center will not be able to obtain information about changes in thermal load and make adjustments in a timely manner. However, due to the pipeline storage effect of the thermal system, the load changes will not be immediately transmitted to the heat source. This means that even if the information node fails, the heat source will still maintain the previous heat output and will not be adjusted for the time being. Therefore, in the fault response stage, the thermal system is less sensitive to information node failure than the power system due to its buffering characteristics.

[0110] (27);

[0111] In the formula, Thermal Node exist The heat source output at the moment, the heat information node ( ) and its thermal power generation node ( ) corresponding to.

[0112] The fault response optimization model aims to minimize the proportion of power load loss, thermal load loss, and information node failure. The input variables of the model include the fault state after the attack, the state of the transmission line, and the working state of the information node.

[0113] (1) Objective function:

[0114] (28);

[0115] In the formula, Thermal Node The required heat load, For power nodes exist The power load loss at the moment, Thermal Node exist The heat load loss at the moment, for The number of loss information nodes at time, is the number of information nodes, It is the time of the fault response phase.

[0116] (2) Constraints:

[0117] 1) Information system constraints:

[0118] Same as formula (8) - formula (14);

[0119] The working status of information nodes is affected by the power supply status and whether the information system is equipped with an uninterruptible power supply (UPS). It is also affected by information attacks:

[0120] (29);

[0121] In the formula, Information Node exist The fault state after being attacked by information at any time. 0 means the information node Being effectively attacked; Information Node exist Whether the uninterruptible power supply is installed at the moment. A value of 1 indicates a valid installation.

[0122] 2) Power system constraints:

[0123] Same as formula (16), formula (19)-formula (20);

[0124] (30);

[0125] (31);

[0126] (32);

[0127] (33);

[0128] In the formula, For Line exist The fault state after being physically attacked at all times. When it is 0, the line is faulty.

[0129] Equations (30) and (31) are branch flow constraints, and equations (32) and (33) are actual power loads. Demand power load relationship constraints.

[0130] 3) Thermal system constraints:

[0131] Same as formula (21);

[0132] (34);

[0133] (35);

[0134] (36);

[0135] In the formula, for The thermal output power of the electric boiler at each moment; for The heat output power of the combined heat and power generation at the moment. Formula (34) indicates that the heat source output is composed of the combined heat and power generation and the electric boiler, and formulas (35)-(36) are the actual thermal loads Demand heat load relationship constraints.

[0136] (4) Coupling element constraints:

[0137] Same as formula (22) to formula (25).

[0138] Step 3: Joint optimization of ETIECPS fault response and recovery:

[0139] 0063. Based on the fault response results in step 2, the fault response and recovery of ETIECPS are jointly optimized. Based on the fault response model, a joint optimization model of fault response and recovery is established. The optimization of this model aims to minimize the load loss of the physical system, minimize the damage of the information system, and minimize the fault recovery time to establish an optimization model, reflecting the response and recovery of the system to multiple faults. Under the joint optimization model of fault response and recovery, fault response and recovery are performed for the input multiple fault scenarios, and finally the resilience curve of each system is output.

[0140] In this step, the ETIECPS fault response and recovery joint optimization is performed for the fault scenarios that meet the conditions output in step 2. The modeling of the fault response in step 2 is not repeated here. This step explains the establishment of the fault recovery model. For faulty information nodes, the model usually performs rapid recovery by dispatching a communication emergency vehicle or a mobile communication vehicle. For damaged power lines, automation functions are usually used for recovery. If the communication function corresponding to the damaged line fails, the circuit breaker recovery and other operations cannot be performed on it through automation functions. Manual repair is required to gradually restore its function. By synchronously restoring the information layer and the physical layer, the model improves the recovery speed and coordination of the overall system.

[0141] (1) Objective function:

[0142] The objective function of the resilience recovery optimization model for joint optimization of fault response and recovery aims to minimize the proportion of power load loss, thermal load loss, information node failure proportion and shorten the resilience recovery time, aiming to achieve the optimal overall resilience of the system.

[0143] (37);

[0144] In the formula, is the time for failure recovery, This is the time for the failure recovery phase.

[0145] (2) Constraints:

[0146] 1) Information system resilience recovery constraints:

[0147] Same as formula (8) - formula (14);

[0148] The working status of the information node is not only affected by the power supply status and whether the information system is equipped with an uninterruptible power supply (UPS), but also by the information fault recovery status:

[0149] (38);

[0150] (39);

[0151] In the formula, Information Node In time Fault recovery status. A value of 1 indicates that the fault has been recovered or no fault has occurred. A value of 0 indicates that the fault has not been recovered.

[0152] The following constraints apply to fault information sites:

[0153] (40);

[0154] (41);

[0155] (42);

[0156] In the formula, and Represents information nodes Fault in The time when the recovery starts and the time when the recovery is completed. When the flag value is 1, it means that the recovery operation of the node starts or completes at the corresponding time point; express The historical moment before the moment , Formula (42) constrains the end time of recovery to be later than the start time of recovery.

[0157] (43);

[0158] (44);

[0159] (45);

[0160] (46);

[0161] In the formula, Represents an information node In time Whether it is in recovery state. A value of 1 indicates that the node is in recovery state, and a value of 0 indicates that the node is not in recovery state. Indicates the duration of a unit of time. Indicates the time required to complete communication recovery. Indicates a communication recovery resource.

[0162] 2) Physical system resilience recovery constraints:

[0163] Same as formula (16), formula (19)-formula (20);

[0164] (47);

[0165] (48);

[0166] In the formula, Indicates power lines time The fault recovery state is 1, which means the power line fault has been restored or no fault has occurred, and 0 means the fault has not been restored. Equations (47) and (48) are branch flow constraints. The difference from the fault response stage is that the fault recovery state is affected here. constraints.

[0167] The following constraints apply to faulty power lines:

[0168] (49);

[0169] (50);

[0170] (51);

[0171] In the formula, and Respectively represent power lines Fault in The time when the recovery starts and the time when the recovery is completed are marked. When the flag value is 1, it means that the recovery operation of the node starts or is completed at the corresponding time point.

[0172] (52);

[0173] (53);

[0174] (54);

[0175] (55);

[0176] In the formula, Indicates power lines In time Whether it is in recovery state. A value of 1 indicates that the node is in recovery state, and a value of 0 indicates that the node is not in recovery state. Indicates the time required to complete the restoration of the power line. represents the additional time required for manual recovery; Formula (52) indicates that information layer failure will affect the automatic operation function, and manual recovery requires additional time, resulting in a longer recovery time; Represents a power line restoration resource.

[0177] 3) Other constraints:

[0178] Same as (21) - (25), (32) - (36);

[0179] The above nonlinear constraints are linearized and solved using a commercial solver.

[0180] Example analysis:

[0181] 1. Case introduction:

[0182] The physical system structure is as follows Figure 4As shown, this embodiment uses an electric-thermal integrated energy information-physical system consisting of a 6-node power system (power nodes B1-B6) and a 6-node thermal system (thermal nodes H1-H6), as well as an information system corresponding to the physical system nodes one by one to verify the effectiveness of the proposed fault response and recovery method. The power system and the thermal system are coupled through a combined heat and power (CHP) device and an electric boiler (EB); G1-G2 represent generator sets, D1-D3 represent power loads, and HD1-HD3 represent thermal loads; ①-⑦ represent power transmission lines, Represents the thermal circuit, Indicates a coupled link line.

[0183] The specific parameter settings in the example are as follows:

[0184] (1) The attack time is set to 0.75h, and the fault recovery time is set to 2.5h;

[0185] (2) Time required for power circuit restoration Set to 0.5h, the extra time required for recovery due to information layer failure Set to 0.25h, the time required for communication recovery Set to 0.5h;

[0186] (3) Communication recovery resources and power line restoration resources All are set to 1;

[0187] (4) Energy supply coupling coefficient According to research convention, 0.75 is taken;

[0188] (5) The simulation step size is set to 0.25h.

[0189] This parameter setting is used to simulate the response and recovery process of the electric-thermal integrated energy cyber-physical system under different fault scenarios, so as to verify the actual effect of the proposed method.

[0190] 2. Result analysis:

[0191] In order to verify the effectiveness of the proposed method, this paper selects several typical fault scenarios for testing. The settings of each scenario are as follows. The fault conditions are shown in Table 1:

[0192] Solution 1: Only physical attacks are applied to the system. Each node of the information system is equipped with a UPS (not relying on the physical system for energy supply), the information-physical coupling is weak, and the pipeline storage effect of the thermal system is considered.

[0193] Solution 2: Only physical attacks are imposed on the system. The information system relies on the physical system for energy supply, the information-physical coupling is enhanced, and the pipeline storage effect of the thermal system is considered.

[0194] Solution 3: Based on Solution 2, ignore the pipeline storage effect of the thermal system.

[0195] Solution 4: Only impose information attacks on the system. The information system relies on the physical system for energy supply, and the pipeline storage effect of the thermal system is considered.

[0196] Solution 5: Inflict cyber-physical coordinated attacks on the system. The cyber system relies on the physical system for energy, and the pipeline storage effect of the thermal system is considered.

[0197] Plan 6: Based on Plan 5, the system is equipped with sufficient defense resources, reducing the attack from multiple transmission lines (②, ④, ⑥) to one transmission line (②), and reducing the attack from multiple information nodes (the information nodes corresponding to power nodes B1 and B4) to one information node (the information node corresponding to power node B1).

[0198] Table 1 Failure scenarios of various solutions

[0199] .

[0200] The three system resilience curves of various schemes are as follows: Figure 5 , Figure 6 and Figure 7 shown.

[0201] (1) Comparison between Scheme 1 and Scheme 2: Both Scheme 1 and Scheme 2 only attack the physical system, but the information system in Scheme 1 is equipped with UPS, so its power supply is not affected by the failure of the physical system. Figure 5 It shows that the load loss in the fault response phase of Scheme 2 is greater. Figure 7 It shows that the information system in Scheme 2 has node failures, while Scheme 1 has no failed nodes. This shows that the proposed method can effectively reflect the impact of information-physical coupling. If this coupling effect is ignored in resilience research, it may lead to a large deviation in the analysis results.

[0202] (2) Comparison between Scheme 2 and Scheme 3: Both Scheme 2 and Scheme 3 were subjected to physical power attacks and caused load loss in the thermal system, reflecting the electrical-thermal coupling effect. Scheme 3 further ignores the pipe storage effect of the thermal system on the basis of Scheme 2. Figure 6It can be seen from the thermal load toughness curve that Scheme 2 considering the pipe storage effect is slower than Scheme 3 in both the fault response and recovery stages, which indicates that the delayed effect of the thermal system helps buffer load fluctuations. This result proves that the proposed method can effectively capture the electrical-thermal coupling characteristics and consider the pipe storage effect of the thermal system in the modeling, making the analysis more in line with the actual situation.

[0203] (3) Comparison between Scheme 2 and Scheme 4: Scheme 2 only imposes physical attacks on the system. Figure 7 It shows that there are faulty nodes in its information system; Scheme 4 only applies information attack, Figure 5 It shows that the physical power system also suffers from load loss, which further reflects the coupling effect between the physical system and the cyber system. This comparison result verifies that the proposed method can effectively reflect the role of cyber-physical coupling in fault propagation.

[0204] (4) Comparison of Scheme 2, Scheme 4 and Scheme 5: Scheme 2 and Scheme 4 only apply physical attack or information attack respectively, while Scheme 5 applies coordinated attack of information and physics. Comparison of resilience curves of the three systems ( Figure 5-Figure 7 ) It can be seen that the cyber-physical coordinated attack brings the greatest harm, and the resilience of the three systems in Scheme 5 is the worst. This result shows that in resilience research, considering physical or cyber attacks alone is not enough to fully evaluate system resilience. It is also necessary to pay attention to cyber-physical coordinated attacks at the same time to more accurately reflect the vulnerability of the system.

[0205] (5) Comparison between Scheme 5 and Scheme 6: Scheme 6 configures more defense resources than Scheme 5. Comparing the resilience curves, it can be seen that Scheme 6 has significantly better resilience performance than Scheme 5 in the three systems. This shows that the proposed method can not only effectively reflect the resilience performance of the system under various attack scenarios, but also sensitively capture the response of the system when defense resources increase, indicating that the proposed method has high recognition and adaptability to the performance of various response strategies.

[0206] In summary, the present invention establishes a fault response model under the ETIECPS framework, fully considers the multiple coupling relationships of power, thermal and information systems, models the impact of the information layer on the physical layer during the fault response phase, and realizes the simulation of fault propagation and response characteristics under multi-system deep coupling scenarios. The resilience recovery model proposed in the present invention is also based on the ETIECPS framework, comprehensively considers the impact of the information layer on the physical layer during the recovery phase, and realizes a rapid response and optimized fault recovery process through the collaborative recovery mechanism of the information-physical system, thereby improving the system's recovery efficiency and overall stability under multiple attack scenarios.

Claims

1. A method for fault response and recovery of an electric-thermal integrated energy information-physical system, characterized in that: The following steps are involved: Step 1: Establish an electric-thermal integrated energy information-physical system model: At the physical level, the power system and thermal system are modeled, and the coupled system of the two is modeled. Through the modeling at the physical level, the flow path and interaction of energy in the physical system are established; at the information level, the corresponding information system is established for the power system and thermal system; at the information-physical coupling level, the synergistic relationship between information and physics is modeled to describe the interaction between the two; Step 2: Establish a fault response optimization model: Based on the electric-thermal integrated energy information-physical system model in step 1, consider the multi-level impacts under multiple fault scenarios, including the impact of load loss in the physical system on the information system, and the impact of information system failure on the physical system, and establish a fault response optimization model with the optimization goal of minimizing physical layer load loss and information layer damage; The input variable of the fault response optimization model is the fault state after the attack, and the objective function is: （28）； In the formula, Thermal Node Demand heat load; For power nodes exist The power load loss at the moment; Thermal Node exist Thermal load loss at the moment; for The number of loss information nodes at the moment; is the number of information nodes; is the time of the fault response phase; A collection of nodes representing a power system; A collection of nodes representing a thermal system; Represents a power node Demand power load; Step 3: Jointly optimize fault response and recovery: Based on the fault response results of the fault response optimization model in step 2, the fault response and recovery of the electric-thermal integrated energy cyber-physical system are jointly optimized; Based on the fault response optimization model, with the optimization objectives of minimizing the load loss of the physical system, minimizing the damage of the information system, and minimizing the fault recovery time, a joint optimization model of fault response and recovery is established to reflect the response and recovery of the system to various faults. Under the joint optimization model of fault response and recovery, fault response and recovery are performed for the input multiple fault scenarios, and finally the resilience curve of each system is output. The objective function of the fault recovery model for joint optimization of fault response and recovery in step 3 is: （37）； In the formula, The time for failure recovery; The duration of the failure recovery phase; The constraints of the fault recovery model for joint optimization of fault response and recovery include: 1) Information system resilience recovery constraints: Same as formula (8) - formula (14); The working status of the information node is not only affected by the power supply status and whether the information system is equipped with an uninterruptible power supply (UPS), but also by the information fault recovery status: （38）； （39）； In the formula, Information Node In time Fault recovery status, a value of 1 indicates that the fault has been recovered or no fault has occurred, and a value of 0 indicates that the fault has not been recovered; Information Node exist The working status at all times: when both power supply and communication are in normal state, the information node works normally; Information Node exist Energy supply status at all times; Information Node exist Whether the uninterruptible power supply is installed at the moment, and a value of 1 represents a valid installation; The following constraints apply to fault information sites: （40）； （41）； （42）； In the formula, and Information Node Fault in The time when the recovery starts and the time when the recovery is completed. When the flag value is 1, it means that the recovery operation of the node starts or completes at the corresponding time point; for The historical moment before the moment, and Information Node Fault in The time when the recovery starts and the time when the recovery is completed are marked; Formula (42) constrains that the time when the recovery ends must be later than the time when the recovery starts; （43）； （44）； （45）； （46）； In the formula, Information Node In time Whether it is in recovery state. A value of 1 indicates that the node is in recovery state, and a value of 0 indicates that the node is not in recovery state. is the duration of the unit time; The time required to complete restoration of communications; recover resources for communications; 2) Physical system resilience recovery constraints: Including formula (16), formula (19)-formula (20); （47）； （48）； In the formula, For power lines time The fault recovery state of , the value of 1 indicates that the power line fault has been restored or no fault has occurred, and the value of 0 indicates that the fault has not been restored; Equation (47)-Equation (48) are branch power flow constraints; For power lines exist The branch power at the moment; For power nodes The voltage phase angle; For power nodes The voltage phase angle; For power lines Impedance; is the upper limit of line power; The following constraints apply to faulty power lines: （49）； （50）； （51）； In the formula, and Power lines Fault in The time when the recovery starts and the time when the recovery is completed. When the flag value is 1, it means that the recovery operation of the node starts or completes at the corresponding time point; and Power lines Fault in The time when the recovery starts and the time when the recovery is completed; （52）； （53）； （54）； （55）； In the formula, For power lines In time Whether it is in recovery state. A value of 1 indicates that the node is in recovery state, and a value of 0 indicates that the node is not in recovery state. The time required to complete the restoration of power lines; is the extra time required for manual recovery; Formula (52) indicates that information layer failure will affect the automatic operation function, and manual recovery requires extra time, resulting in a longer recovery time; restoring resources for power lines; 3) Other constraints: Including formula (21)-formula (25), formula (32)-formula (36).

2. The method for fault response and recovery of an electric-thermal integrated energy information-physical system according to claim 1, characterized in that: The step 1 specifically includes: Step 1.1: Establish the coupling relationship between cyber-physical systems: The physical elements and information elements in the physical system are abstracted as nodes, and the power system model is ,in and Represent the node set and line set of the power system respectively; the thermal system model is ,in and Represent the node set and line set of the thermal system respectively; the information system model is ,in and They are the node set and line set of the information system respectively; Use the information-physics correlation matrix to describe the coupling relationship between information and physics: （1）； （2）； （3）； （4）； （5）； in, is the cyber-physical correlation matrix; is the information connection matrix, ; is the physical connection matrix, ; Represents the measurement and control relationship between the information system and the physical system. Its elements If it is 1, it means that the information layer has a measurement and control function on the physical layer, and if it is 0, it means that there is no measurement and control function; Represents the energy supply relationship between physical nodes and information nodes. Its elements If it is 1, it means that the physical node has a power supply relationship with the information node, and if it is 0, it means that there is no power supply effect; For the power information connection matrix, Connect the matrix for thermal information; and is an information node; is the power physical connection matrix, is the thermophysical connection matrix; and For power nodes; Step 1.2: Build an information system model: The working status of the information node is expressed as: （6）； In the formula, Information Node exist The working status at all times: when both power supply and communication are in normal state, the information node works normally; The working status of the information line is expressed as: （7）； In the formula, For information lines exist Working status at all times, when the information line When there is communication traffic, its value is 1. ; The energy supply status of the information node is expressed as: （8）； In the formula, Information Node exist The energy supply status at all times, and Represents power nodes The actual power load and the demand power load, is the energy supply coupling coefficient, the power node With information node The relationship between Decide; The node communication flow balance is expressed as: （9）； In the formula, is the information node-source node association matrix, is the information node-information line association matrix, for The information flow matrix of the source end at each moment; for The working status matrix of the moment information node; for The communication flow matrix of the information line at the moment; The line communication flow must be within the supply range and is subject to the working status of the information nodes it connects: （10）； （11）； （12）； （13）； In the formula, is the maximum value of line communication flow, is the number of information lines, for Time information node working status, for Time information node Working status; for Time information line of communication traffic; The amount of information at the source must be within the supply range: （14）； In the formula, for The information flow of the source end at all times; The working status of the information node is constrained by the power supply status: （15）； Step 1.3: Build the power system model: The power system model adopts the DC power flow model, and the power balance relationship is as follows: （16）； In the formula, for The power matrix of power generation at each moment; for The power matrix of combined heat and power generation at all times; for Load power matrix at the moment; for The electric boiler load power matrix at the moment; for The branch power matrix at time t; , , , and They are the power node-generation node association matrix, the power node-cogeneration node association matrix, the power node-load node association matrix, the power node-electric boiler node association matrix, and the power node-branch association matrix; Branch flow relationship: （17）； In the formula, For power lines exist The branch power at the moment; For power nodes The voltage phase angle; For power nodes The voltage phase angle; For power lines Impedance; Runtime safety constraints: （18）； （19）； （20）； In the formula, is the upper limit of line power; and Power Node The upper and lower limits of the voltage phase angle; For power nodes The generator at The power generation at the time; and Power Node The upper and lower limits of the generator power generation capacity at the location; Step 1.4: Build a thermal system model: The relationship between heat source output and heat demand is as follows: （21）； In the formula, for The heat source output matrix at each moment; for Thermal load power matrix at each moment; for The heat generation power matrix entering the water supply network at all times; and are the heat transfer coupling matrices of the heating network and the heat recovery network respectively; is the identity matrix; Step 1.5: Build the coupling element model: The coupling element includes the combined heat and power generation and the electric boiler, which is described by its operating efficiency conversion equation: （22）； （23）； In the formula, for The thermal output power matrix of CHP at each moment; The conversion efficiency of combined heat and power generation; and They are the upper and lower limits of combined heat and power generation power, respectively; It is a combined heat and power generation power matrix; （24）； （25）； In the formula, for Thermal power matrix of electric boiler heat output at each moment; is the conversion efficiency of the electric boiler, and The upper and lower limits of the electric boiler load power; is the electric boiler load power matrix.

3. The method for fault response and recovery of an electric-thermal integrated energy information-physical system according to claim 2, characterized in that: The step 2 specifically includes: Step 2.1: In the fault response stage, the process of absorbing the unbalanced power of the system is simplified to the process of removing the uncontrollable units to achieve system power balance and frequency recovery, which can be expressed as: （26）； Step 2.2: In the fault response phase, the buffering characteristics of the thermal system are expressed as: （27）； In the formula, Thermal Node exist Heat output at all times; Step 2.3: Set the input variable of the fault response optimization model to the fault state after the attack, and set the objective function; Step 2.4: Set up constraints: 1) Information system constraints: The working state of the information node is affected by the power supply state, whether the information system is equipped with an uninterruptible power supply, and is also affected by information attacks. The constraints are as follows: （29）； In the formula, Information Node exist The fault state after being attacked by information at any time. 0 means the information node Under effective attack; Information Node exist Whether the uninterruptible power supply is installed at the moment, and a value of 1 represents a valid installation; It also includes: formula (8)-formula (14); 2) Power system constraints: （30）； （31）； （32）； （33）； In the formula, For Line exist The fault state after the physical attack at any moment, when it is 0, the line is faulty; Formula (30)-Formula (31) is the branch flow constraint, Formula (32)-Formula (33) is the actual power load Demand power load Relationship constraints; Also includes: Formula (16), Formula (19)-Formula (20); 3) Thermal system constraints: （34）； （35）； （36）； In the formula, They are The thermal output power of the electric boiler at each moment; They are The heat output power of the cogeneration at the moment; Formula (34) is the heat source output composed of cogeneration and electric boiler; Formula (35)-Formula (36) are the actual thermal load Demand heat load Relationship constraints; It also includes: Formula (21); 4) Coupling element constraints: Including formula (22) to formula (25).

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