Comprehensive energy system fault simulation method and system based on multi-energy flow coupling

Abstract

The invention discloses an integrated energy system fault simulation method and system based on multi-energy flow coupling, and belongs to the technical field of integrated energy systems. According to the system fault simulation method disclosed by the invention, the coupling element hydrogen fuel cell and the electrolytic cell are modeled according to the bidirectional coupling characteristic of the hydrogen energy-electric power integrated energy system, so that the defect that the prior art is generally concentrated on a single energy system (such as an electric power system or a hydrogen energy system) is overcome; according to the method, the blank that mutual influence of faults in a multi-energy coupling system is lack of deep research is overcome, meanwhile, the real fault propagation process of the comprehensive energy system is simulated to the maximum extent through the dynamic simulation technology, compared with traditional static analysis, the method is more visual and efficient, and dynamic capture of fault propagation rules can be achieved in a complex system; and researchers and operators are helped to identify potential risks in time.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated energy systems, and in particular relates to an integrated energy system fault simulation method and system based on multi-energy flow coupling. Background Art

[0002] With the continuous optimization of the global energy structure and the rapid development of clean energy technology, the advantages of integrated energy systems in terms of efficient energy utilization and clean energy consumption are becoming increasingly significant. As a clean and efficient secondary energy source, hydrogen has application scenarios covering industry, transportation and power, and has gradually become an important part of the energy field. Against this background, an integrated energy system with deep coupling of hydrogen and electricity has emerged. Through the efficient conversion and complementary synergy between hydrogen and electricity, this system achieves the optimal allocation of energy resources and the improvement of utilization efficiency, providing a new approach to energy security, environmental protection and energy transformation. However, the operational complexity of the multi-energy coupled integrated energy system has increased significantly, especially in the coordinated operation of hydrogen and power systems, where there are many potential operational risks. These risks include but are not limited to accidents that may be caused by external environmental factors such as equipment aging or failure, system operation errors, and extreme weather. These problems may lead to local failures and form a chain reaction within the system, ultimately causing a larger range of failures to spread or system collapse. For example, failures in hydrogen production, storage and transportation equipment may affect the power supply system; conversely, grid failures may also affect the normal operation of hydrogen production and energy storage equipment. This bidirectional coupling characteristic makes the propagation and evolution of faults more complex and difficult to predict.

[0003] At present, the application of simulation technology in the energy field is mostly focused on a single energy system, such as a pure electric system or a single hydrogen energy system, and few studies can fully and deeply explore the complex and subtle coupling relationship between multiple energy systems. This limitation makes it difficult for us to accurately understand and predict the behavior patterns of multiple energy systems in actual operation; in addition, traditional simulation technologies mostly rely on static models or quasi-static analysis methods, which may be sufficient when dealing with simple and stable energy systems, but in the face of complex and changeable energy systems, especially in the case of faults, its dynamic evolution process is often difficult to be truly and accurately reproduced. Therefore, the simulation results often have a large deviation from the actual situation, and cannot provide strong support for the optimal design and safe operation of the energy system; in order to overcome these challenges, we need to explore more advanced and comprehensive simulation technologies to more accurately simulate and predict the behavior of multiple energy systems under various conditions, and provide strong guarantees for the sustainable development of energy systems. Summary of the invention

[0004] The purpose of the present invention is to provide a comprehensive energy system fault simulation method and system based on multi-energy flow coupling, which is used to solve the technical problem that existing prediction methods are difficult to simulate faults in multi-energy coupling systems.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a comprehensive energy system fault simulation method based on multi-energy flow coupling, comprising the following steps:

[0007] The hydrogen-electricity integrated energy system comprises a coupled hydrogen energy subsystem and an electric power subsystem;

[0008] When a fault occurs in the hydrogen energy subsystem, an initial fault is randomly injected into the hydrogen energy subsystem, and then the fault evolution process is simulated based on whether the gas transmission volume of the hydrogen energy subsystem fed back by the injected initial fault meets the needs of the power subsystem.

[0009] When a fault occurs in the power subsystem, an initial fault is randomly injected into the power subsystem, and then the fault evolution process is simulated based on whether the power of the electrolyzer in the power subsystem fed back by the injected initial fault is affected.

[0010] Furthermore, when a fault occurs in the hydrogen energy subsystem, the fault evolution process simulation method includes the following steps:

[0011] S1: Collect and initialize the parameters of the hydrogen-electricity integrated energy system, set the simulation time interval and format it, and then enter S2;

[0012] S2: randomly inject initial faults into the hydrogen energy subsystem and proceed to S3;

[0013] S3: Collect the influence trend of the fault side on the gas transmission volume after the hydrogen energy subsystem is injected with the initial fault, draw the gas transmission volume change curve of the hydrogen energy subsystem according to the influence trend, and transfer to S4;

[0014] S4: At a certain number of simulation time intervals, according to the gas flow change curve, increase the gas flow on the non-fault side. After the simulation time interval, determine whether a normal working device and pipeline in the hydrogen energy subsystem has reached the maximum load. If so, proceed to S3, otherwise proceed to S5.

[0015] S5: The fault is transferred to the power subsystem. The hydrogen fuel cell power of the power subsystem is affected. The power subsystem starts flow dispatching to reduce the load until the power subsystem reaches a balanced state and then enters S6;

[0016] S6: Check whether each transmission line of the power subsystem exceeds the maximum load. If so, update the power subsystem topology and go to S5. If not, go to S7. If the power of the electrolytic cell of the coupling element in the system is affected, wait until the power subsystem is restored to balance and go to S3.

[0017] S7: If the gas transmission volume of the hydrogen energy subsystem after the current time node meets the gas transmission volume required by the power subsystem and reaches a balanced state, then proceed to S8; otherwise, the time node is advanced and proceed to S4;

[0018] S8: Calculate the load loss of the hydrogen-electricity integrated energy system and record the evolution process of the cascading failures of the hydrogen-electricity integrated energy system.

[0019] Further, in S1, simulating the time interval and formatting it includes the following steps:

[0020] The simulation time interval is set to △T; the △T satisfies the following relationship:

[0021] △T p <△T;

[0022] Among them, △T p It indicates the time required for the power subsystem to complete the power flow dispatch;

[0023] In S3, the influence trend of the fault side on the gas transmission volume after the hydrogen energy subsystem is injected with the initial fault is collected, and the specific process of drawing the gas transmission volume change curve of the hydrogen energy subsystem according to the influence trend includes:

[0024] The impact trend of the fault side on the gas transmission volume after the initial fault is injected into the hydrogen energy subsystem is collected, and compared with the maximum gas transmission volume on the non-fault side, the flow scheduling strategy and fault evolution strategy of the hydrogen energy subsystem are determined. The gas transmission volume change curve of the hydrogen energy subsystem is drawn based on the flow scheduling strategy and fault evolution strategy. Whenever a new fault propagates to the hydrogen energy subsystem, the gas transmission volume change curve is corrected in time.

[0025] Furthermore, when a fault occurs in the power subsystem, the fault evolution process simulation method includes the following steps:

[0026] S11: Collect and initialize the parameters of the hydrogen-electricity integrated energy system, and then proceed to S22;

[0027] S22: randomly injecting initial faults into the power subsystem and proceeding to S33;

[0028] S33: The power subsystem starts flow dispatching to reduce load until the power subsystem reaches a balanced state, and then proceeds to S44;

[0029] S44: Detect whether each transmission line of the power subsystem exceeds the maximum load. If so, update the power subsystem topology and go to S33; if not, go to S55;

[0030] S55: If the hydrogen production of the electrolyzer of the coupling element in the power subsystem is affected during the power flow dispatching process, the process proceeds to S66, otherwise the process proceeds to S77;

[0031] S66: The fault is transmitted to the hydrogen energy subsystem through the electrolyzer. The hydrogen energy subsystem adjusts the gas transmission volume to determine whether the coupled element hydrogen fuel cell in the system is affected. If so, it goes to S33, otherwise it goes to S77;

[0032] S77: Balance of hydrogen-electricity integrated energy system, calculate the load loss of hydrogen-electricity integrated energy system, and construct the chain failure propagation process.

[0033] Furthermore, the parameters collected for the hydrogen-electricity integrated energy system include a hydrogen energy subsystem data set, an electric power subsystem data set, and coupling node data;

[0034] The hydrogen energy subsystem data set includes the topological structure of the hydrogen energy subsystem, node gas transmission volume, pipeline gas flow and gas network node parameters;

[0035] The power subsystem data set includes the topological structure of the power subsystem, node injection power, line flow and transmission line parameters;

[0036] The coupling node data includes the location and energy conversion efficiency of the coupling nodes in the hydrogen-electricity integrated energy system.

[0037] Furthermore, in S2 and S22, the injection of the initial fault satisfies the conditions that cause Nk chain failures to occur in the hydrogen-electricity integrated energy system; the types of the initial faults include extreme weather, equipment failure or human error.

[0038] Furthermore, the model of the hydrogen fuel cell of the power subsystem is:

[0039] P w,m (t) = β w Q w,m (t)·HHV,w∈Ω HT ,m∈Ω BUS ;

[0040] Among them, Ω HT ——The set of all hydrogen power generation nodes in the power subsystem; Ω BUS ——The collection of all nodes in the power subsystem; P w,m (t)——output of hydrogen fuel cell node w / MW; β w——Energy conversion coefficient of hydrogen fuel cell node w; Q w,m (t)——gas consumption of hydrogen fuel cell node w / m 3 ·s -1 ; HHV——Higher heating value of hydrogen / J·kg -1 .

[0041] Furthermore, the objective function of the optimal power flow model for power subsystem power flow dispatch is:

[0042]

[0043] Among them, Ω Load ——The collection of all load nodes of the power subsystem; P L,m ——Load demand of node L / MW; C m ——Power subsystem load reduction cost weight coefficient; Ω BUS ——The collection of all nodes in the power subsystem;

[0044] The constraint equations are:

[0045]

[0046] P l =(θ m -θ n ) / X l ;

[0047]

[0048] Among them, Ω HT ——The set of all hydrogen power generation nodes in the power subsystem; Ω BUS ——The collection of all nodes in the power subsystem; P w,m ——Output of hydrogen fuel cell node w / MW; P L,m ——Load demand of node L / MW; θ m ,θ n ——The phase angle between m and n at both ends of line l / °; and ——Minimum and maximum power flows of transmission line l / MW; and ——Minimum and maximum output of hydrogen fuel cell node w / MW; ——Maximum power flow load of node L / MW.

[0049] Furthermore, the electrolytic cell model is:

[0050]

[0051] Among them, Ω P2G——The set of all coupled element electrolyzer nodes; Ω NODE ——The collection of all nodes of the hydrogen energy subsystem; Q d,i (t)——gas production at electrolytic cell node d / m 3 ·s -1 ;ω d ——Energy conversion coefficient of electrolyzer node d; HHV——Higher heating value of hydrogen / J·kg -1 ;P d,i (t)——electric energy input to the electrolyzer node d / MW;

[0052] The model for the load loss case is:

[0053]

[0054] in, ——The load of power node m at the initial time / MW; ——Power m is the load at the end of fault evolution / MW; Ω BUS ——The set of all nodes in the power subsystem; Ω Load ——The collection of all load nodes of the power subsystem; ——Total power load shedding of the hydrogen-electricity integrated energy system under cascading failures / MW.

[0055] The invention also discloses a fault simulation system of the method.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] The present invention discloses a comprehensive energy system fault simulation method based on multi-energy flow coupling. Aiming at the bidirectional coupling characteristics of the hydrogen energy-electricity comprehensive energy system, the coupling elements hydrogen fuel cell and electrolyzer are modeled, which makes up for the fact that the existing technology usually focuses on a single energy system (such as an electric power system or a hydrogen energy system) and lacks in-depth research on the mutual influence of faults in the multi-energy coupling system. From the perspective of the overall system, it provides an innovative solution for the fault analysis of the multi-energy coupling system.

[0058] Furthermore, the method of the present invention adopts dynamic simulation technology, and simulates the fault evolution process and self-regulation process in the system in real time to simulate the real fault propagation process of the integrated energy system to the greatest extent, and can more accurately predict the propagation path and range of the fault. This method is more intuitive and efficient than traditional static analysis, and can dynamically capture the fault propagation law in complex systems, helping researchers and operators to identify potential risks in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1It is a flow chart of the integrated energy system fault simulation method based on multi-energy flow coupling;

[0060] Figure 2 A flow chart of a fault simulation method when a fault occurs in a hydrogen energy subsystem;

[0061] Figure 3 The flowchart of the fault simulation method is shown in FIG. 1 when a fault occurs in the power subsystem. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0064] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0065] like Figure 1 As shown, the present invention discloses a comprehensive energy system fault simulation method based on multi-energy flow coupling, including two simulation situations: the initial fault occurs in the hydrogen energy subsystem and the initial fault occurs in the power subsystem.

[0066] When a fault occurs in the hydrogen energy subsystem, such as Figure 2 As shown, the following steps are included:

[0067] S1: Initialize the parameters of the hydrogen-electricity integrated energy system, set the simulation time interval, and then enter S2;

[0068] S2: Randomly inject an initial fault into the hydrogen energy subsystem. This initial fault can cause Nk cascading faults in the hydrogen energy-electricity integrated energy system and then enter S3;

[0069] S3: Collect the influence trend of the fault side on the gas transmission volume after the initial fault is injected into the hydrogen energy-electricity integrated energy system, draw the gas transmission volume change curve of the hydrogen energy subsystem according to the influence trend, and transfer to S4;

[0070] S4: In T n (n=1, 3, 5…), that is, within n simulation time intervals, according to the gas flow change curve, increase the gas flow on the non-fault side. After the simulation time interval, determine whether a normal working component or pipeline in the hydrogen energy subsystem has reached the maximum load. If so, go to S3, otherwise go to S5;

[0071] S5: In T 2n (n=1, 3, 5...), as the gas transmission volume changes, the hydrogen fuel cell power of the hydrogen-electricity integrated energy system is affected, and the power subsystem starts flow dispatching, and load reduction is carried out in order from low to high load importance until the power subsystem reaches a balanced state and enters S6;

[0072] S6: Check whether each transmission line of the power subsystem exceeds the power limit. If a line reaches the power limit, trip the line and update the power subsystem topology, and go to S5. Otherwise, go to S7. If the power of the electrolyzer is affected during the power subsystem flow dispatching process, go to S3 after the subsystem is restored to balance.

[0073] S7: If the gas supply of the hydrogen energy subsystem after the current time node meets the gas supply required by the power subsystem and reaches a balanced state, then go to S8; otherwise, the time node is advanced and go to S4;

[0074] S8: Calculate the load loss of the hydrogen-electricity integrated energy system; record the evolution process of cascading failures of the hydrogen-electricity integrated energy system.

[0075] When a fault occurs in the power subsystem, such as Figure 3 As shown, the following steps are included:

[0076] S11: Collect and initialize the parameters of the hydrogen-electricity integrated energy system, and then proceed to S22;

[0077] S22: randomly injecting initial faults into the power subsystem and proceeding to S33;

[0078] S33: The power subsystem starts flow dispatching and reduces loads in order of load importance from low to high until the power subsystem reaches a balanced state and then proceeds to S44;

[0079] S44: Detect whether each transmission line of the power subsystem exceeds the power upper limit. If a line reaches the power upper limit, the line is tripped, and the power system topology is updated, and the process goes to S33. Otherwise, the process goes to S55.

[0080] S55: If the hydrogen production of the electrolyzer of the power subsystem is affected during the power flow dispatching process, the process proceeds to S66; otherwise, the process proceeds to S77;

[0081] S66: The fault is transmitted to the hydrogen energy subsystem through the electrolyzer. The hydrogen energy subsystem maintains the subsystem balance by adjusting the gas output of other components and then proceeds to S77. If the gas output of the fuel cell is affected during the adjustment process, then immediately proceeds to S33.

[0082] S77: Balance of hydrogen-electricity integrated energy system, calculate the load loss of hydrogen-electricity integrated energy system, and construct the chain failure propagation process.

[0083] Preferably, in S1 and S11, the data collection and initialization contents are as follows:

[0084] The system collected data includes the power subsystem data set, hydrogen energy subsystem data set and coupling node data. The power subsystem data set includes the topological structure of the power subsystem, node injection power, line flow, transmission line parameters and other data information; the hydrogen energy subsystem data set includes the system topological structure, node gas transmission volume, pipeline gas flow, gas network node parameters and other data information; the coupling node data includes the location of the coupling node in the system, energy conversion efficiency and other information.

[0085] Preferably, in S1, the simulation time interval formatting content is as follows:

[0086] Set the simulation time interval to unit time △T, △T requirement is:

[0087] △T p ≤△T;

[0088] Among them, △T p It indicates the time required for the power subsystem to complete power flow scheduling.

[0089] Preferably, in S2 and S22, the initial fault content is set as follows:

[0090] The system simulates initial failures caused by emergencies such as extreme weather, equipment failure, and human error, including pipeline freezing, pipeline shutdown, and hydrogen storage bottle group failure; such initial failures can cause Nk chain failures in the hydrogen-electricity integrated energy system.

[0091] Preferably, in S3, the impact of the hydrogen energy subsystem on the components and gas pipeline after the initial fault is injected is collected, and the flow scheduling strategy and fault evolution strategy of the hydrogen energy subsystem are determined based on the maximum gas output of the normally working components, and the gas output change curve of the hydrogen energy subsystem is drawn, and the change curve is promptly corrected whenever a new fault propagates to the hydrogen energy subsystem.

[0092] Preferably, in S5 and S66, the hydrogen fuel cell model is:

[0093] P w,m (t) = β w Q w,m (t)·HHV,w∈Ω HT ,m∈Ω BUS ;

[0094] Among them, Ω HT ——The set of all hydrogen power generation nodes in the power subsystem; Ω BUS ——The collection of all nodes in the power subsystem; P w,m (t)——output of hydrogen fuel cell node w / MW; β w ——Energy conversion coefficient of hydrogen fuel cell node w; Q w,m (t)——gas consumption of hydrogen fuel cell node w / m 3 ·s -1 ; HHV——Higher heating value of hydrogen / J·kg -1 .

[0095] Preferably, in S5 and S33, the objective function of the optimal power flow model for power subsystem power flow dispatch is:

[0096]

[0097] Among them, Ω Load ——The collection of all load nodes of the power subsystem; P L,m ——Load demand of node L / MW; C m ——Power subsystem load reduction cost weight coefficient; Ω BUS ——The collection of all nodes in the power subsystem;

[0098] The constraint equations are:

[0099]

[0100] P l =(θ m -θ n ) / X l ;

[0101]

[0102] Among them, Ω HT ——The set of all hydrogen power generation nodes in the power subsystem; Ω BUS ——The collection of all nodes in the power subsystem; P w,m ——Output of hydrogen fuel cell node w / MW; P L,m ——Load demand of node L / MW; θ m ,θ n ——The phase angle between m and n at both ends of line l / °; and ——Minimum and maximum power flows of transmission line l / MW; and ——Minimum and maximum output of hydrogen fuel cell node w / MW; ——Maximum power flow load of node L / MW.

[0103] Preferably, in S6 and S55, the electrolytic cell model is:

[0104]

[0105] Among them, Ω P2G ——The set of all coupled element electrolyzer nodes; Ω NODE ——The collection of all nodes of the hydrogen energy subsystem; Q d,i (t)——gas production at electrolytic cell node d / m 3 ·s -1 ;ω d ——Energy conversion coefficient of electrolyzer node d; HHV——Higher heating value of hydrogen / J·kg -1 ;P d,i (t)——Electric energy input to the electrolyzer node d / MW.

[0106] Preferably, the load loss case is modeled as:

[0107]

[0108] in, ——The load of power node m at the initial time / MW; ——Power m is the load at the end of fault evolution / MW; Ω BUS ——The set of all nodes in the power subsystem; Ω Load ——The collection of all load nodes of the power subsystem; ——Total power load shedding of the hydrogen-electricity integrated energy system under cascading failures / MW.

[0109] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A comprehensive energy system fault simulation method based on multi-energy flow coupling, characterized in that: The hydrogen-electricity integrated energy system comprises a coupled hydrogen energy subsystem and an electric power subsystem; The following steps are involved: When a fault occurs in the hydrogen energy subsystem, an initial fault is randomly injected into the hydrogen energy subsystem, and then the fault evolution process is simulated based on whether the gas transmission volume of the hydrogen energy subsystem fed back by the injected initial fault meets the needs of the power subsystem. When a fault occurs in the power subsystem, an initial fault is randomly injected into the power subsystem. Then, the fault evolution process is simulated based on whether the output power of the electrolyzer in the power subsystem fed back by the injected initial fault is affected.

2. According to claim 1, a comprehensive energy system fault simulation method based on multi-energy flow coupling is characterized in that: When a fault occurs in the hydrogen energy subsystem, the fault evolution process simulation method The following steps are involved: S1: Collect and initialize the parameters of the hydrogen-electricity integrated energy system, set the simulation time interval and format it, and then enter S2; S2: randomly inject initial faults into the hydrogen energy subsystem and proceed to S3; S3: Collect the influence trend of the fault side on the gas transmission volume after the hydrogen energy subsystem is injected with the initial fault, draw the gas transmission volume change curve of the hydrogen energy subsystem according to the influence trend, and then proceed to S4; S4: At a certain number of simulation time intervals, according to the gas flow change curve, increase the gas flow on the non-fault side. After the simulation time interval, determine whether a normal working device or pipeline in the hydrogen energy subsystem has reached the maximum load. If so, proceed to S3, otherwise proceed to S5. S5: The fault is transferred to the power subsystem. The power of the hydrogen fuel cell in the power subsystem is affected. The power subsystem starts flow dispatching to reduce the load until the power subsystem reaches a balanced state and then enters S6; S6: Check whether each transmission line of the power subsystem exceeds the maximum load. If so, update the power subsystem topology and go to S5. If not, go to S7. If the electrolytic cell power of the coupling element in the system is affected, the system will enter S3 after the power subsystem is restored to balance; S7: If the gas transmission volume of the hydrogen energy subsystem after the current time node meets the gas transmission volume required by the power subsystem and reaches a balanced state, then proceed to S8; otherwise, the time node is advanced and proceed to S4; S8: Calculate the load loss of the hydrogen-electricity integrated energy system and record the evolution process of the cascading failures of the hydrogen-electricity integrated energy system.

3. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 2 is characterized in that: In S1, simulating the time interval and formatting it includes the following steps: The simulation time interval is set to △T; the △T satisfies the following relationship: △T p <△T; Among them, △T p It indicates the time required for the power subsystem to complete the power flow dispatch; In S3, the influence trend of the fault side on the gas transmission volume after the hydrogen energy subsystem is injected with the initial fault is collected, and the specific process of drawing the gas transmission volume change curve of the hydrogen energy subsystem according to the influence trend includes: The impact trend of the fault side on the gas transmission volume after the initial fault is injected into the hydrogen energy subsystem is collected, and compared with the maximum gas transmission volume on the non-fault side, the flow scheduling strategy and fault evolution strategy of the hydrogen energy subsystem are determined. The gas transmission volume change curve of the hydrogen energy subsystem is drawn based on the flow scheduling strategy and fault evolution strategy. Whenever a new fault occurs in the hydrogen energy subsystem, the gas transmission volume change curve is corrected in time.

4. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 1 is characterized in that: When a fault occurs in the power subsystem, the fault evolution process simulation method includes the following steps: S11: Collect and initialize the parameters of the hydrogen-electricity integrated energy system, and then proceed to S22; S22: randomly injecting initial faults into the power subsystem and proceeding to S33; S33: The power subsystem starts flow dispatching to reduce load until the power subsystem reaches a balanced state, and then proceeds to S44; S44: Detect whether each transmission line of the power subsystem exceeds the maximum load. If so, update the power subsystem topology and go to S33; if not, go to S55; S55: If the hydrogen production of the electrolyzer of the coupling element in the power subsystem is affected during the power flow dispatching process, the process proceeds to S66, otherwise the process proceeds to S77; S66: The fault is transmitted to the hydrogen energy subsystem through the electrolyzer. The hydrogen energy subsystem adjusts the gas transmission volume to determine whether the coupled element hydrogen fuel cell in the system is affected. If so, it goes to S33, otherwise it goes to S77; S77: Balance of hydrogen-electricity integrated energy system, calculate the load loss of hydrogen-electricity integrated energy system, and construct the chain failure propagation process.

5. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 4 is characterized in that: The parameters collected for the hydrogen-electricity integrated energy system include a hydrogen energy subsystem data set, an electric power subsystem data set, and coupling node data; The hydrogen energy subsystem data set includes the topological structure of the hydrogen energy subsystem, node gas transmission volume, pipeline gas flow and gas network node parameters; The power subsystem data set includes the topological structure of the power subsystem, node injection power, line flow and transmission line parameters; The coupling node data includes the location and energy conversion efficiency of the coupling nodes in the hydrogen-electricity integrated energy system.

6. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 4 is characterized in that: In S2 and S22, the injection of the initial fault satisfies the conditions that cause Nk chain failures to occur in the hydrogen-electricity integrated energy system; the types of the initial faults include extreme weather, equipment failure or human error.

7. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 4 is characterized in that: The model of the hydrogen fuel cell for the power subsystem is: P w,m (t)=β w Q w,m (t)·HHV,w∈Ω HT ,m∈Ω BUS ; Among them, Ω HT ——The set of all hydrogen power generation nodes in the power subsystem; Ω BUS ——The collection of all nodes in the power subsystem; P w,m (t)——output of hydrogen fuel cell node w / MW; β w ——Energy conversion coefficient of hydrogen fuel cell node w; Q w,m (t)——gas consumption of hydrogen fuel cell node w / m 3 ·s -1 ; HHV——Higher heating value of hydrogen / J·kg -1 .

8. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 4 is characterized in that: The objective function of the optimal power flow model for power subsystem power flow dispatch is: Among them, Ω Load ——The collection of all load nodes of the power subsystem; P L,m ——Load demand of node L / MW; C m ——Power subsystem load reduction cost weight coefficient; Ω BUS ——The collection of all nodes in the power subsystem; The constraint equations are: P l =(θ m -θ n ) / X l ; Among them, Ω HT ——The set of all hydrogen power generation nodes in the power subsystem; Ω BUS ——The collection of all nodes in the power subsystem; P w,m ——Output of hydrogen fuel cell node w / MW; P L,m ——Load demand of node L / MW; θ m ,θ n ——The phase angle between m and n at both ends of line l / °; and ——Minimum and maximum power flows of transmission line l / MW; and ——Minimum and maximum output of hydrogen fuel cell node w / MW; ——Maximum power flow load of node L / MW.

9. The method for simulating faults of an integrated energy system based on multi-energy flow coupling according to claim 4 is characterized in that: The electrolytic cell model is: Among them, Ω P2G ——The set of all coupled element electrolyzer nodes; Ω NODE ——The collection of all nodes of the hydrogen energy subsystem; Q d,i (t)——gas production at electrolytic cell node d / m 3 ·s -1 ;ω d ——Energy conversion coefficient of electrolyzer node d; HHV——Higher heating value of hydrogen / J·kg -1 ;P d,i (t)——electric energy input to the electrolyzer node d / MW; The model for the load loss case is: in, ——The load of power node m at the initial time / MW; ——Power m is the load at the end of fault evolution / MW; Ω BUS ——The set of all nodes in the power subsystem; Ω Load ——The collection of all load nodes of the power subsystem; ——Total power load shedding of the hydrogen-electricity integrated energy system under cascading failures / MW.

10. A comprehensive energy system fault simulation system based on multi-energy flow coupling, characterized in that: Used to execute the simulation method described in any one of claims 1 to 9.

Images