Gas-electric coupling system risk assessment method and device, electronic equipment and storage medium

Abstract

This invention discloses a method, apparatus, electronic device, and storage medium for risk assessment of a gas-electric coupling system. It includes: setting the planar coordinates and time coordinates of each component in the gas-electric coupling system; determining the parameters and boundary conditions of the gas-electric coupling system at any given time based on the temperature T and wind speed v corresponding to different planar and time coordinates, performing comprehensive energy flow calculations to obtain the state variables of the gas-electric coupling system operation; setting the limit-exceeding indicators for the state variables of the gas-electric coupling system operation; determining system safety indicators based on the limit-exceeding indicators; and determining system risk indicators based on the system safety indicators and conducting risk assessment accordingly. This method can effectively identify weak links in the gas-electric coupling system under extreme weather conditions, predict the changing trend of system operation risk over time, and provide an effective and accurate assessment of system risk under extreme weather conditions, which has important reference value for ensuring the safe operation of power systems under extreme weather conditions.

Description

Technical Field

[0001] This invention relates to the field of integrated energy system operation and control technology, and in particular to a gas-electric coupling system risk assessment method, device, electronic equipment and storage medium. Background Technology

[0002] In today's era of rapid climate change, once rare weather disasters are no longer uncommon. Many accidents in the power energy system are triggered by extreme weather. In February 2021, a massive power outage caused by extreme storms in Texas, USA, resulted in estimated losses exceeding $195 billion. In this power outage, the collapse of natural gas was a significant contributing factor to the power system failure.

[0003] In existing early warning and control schemes for gas-electric coupling systems, risk assessments mostly focus on the analysis of N-1 anticipated faults, including the definition and scanning of the anticipated fault set, and a detailed analysis of the anticipated faults. This process then identifies weaknesses within the system itself, without considering the impact of external factors such as extreme weather. With the development of natural gas power generation, many regions are experiencing increasingly deeper gas-electric coupling. To ensure the safety of the power system under these circumstances, risk assessments should be conducted considering the entire gas-electric coupling system. Summary of the Invention

[0004] In order to at least partially solve the technical problems existing in the prior art, the inventors made this invention, which, through specific embodiments, provides a method, apparatus, electronic device and storage medium for risk assessment of gas-electric coupling systems.

[0005] In a first aspect, embodiments of the present invention provide a risk assessment method for a pneumatic-electric coupling system, comprising the following steps:

[0006] Set the planar coordinates (x, y) and time coordinates t for each element in the gas-electric coupling system;

[0007] Based on the temperature T and wind speed v corresponding to different plane coordinates and time coordinates, determine the parameters and boundary conditions of the gas-electric coupling system at any time.

[0008] Based on the parameters and boundary conditions of the gas-electric coupling system at any given time, a comprehensive energy flow calculation is performed to obtain the state variables of the gas-electric coupling system, which include node pressure, pipeline flow rate, bus voltage, line power, and load shedding.

[0009] Set the state quantity over-limit indicators for the operation of the gas-electric coupling system;

[0010] Based on the aforementioned state variable limit exceedance indicators, determine the system safety indicators;

[0011] Based on the system safety indicators, system risk indicators are determined, and a risk assessment is performed on the gas-electric coupling system based on the system risk indicators.

[0012] Optionally, determining the parameters and boundary conditions of the gas-electric coupling system at any given time based on the temperature T and wind speed v corresponding to different planar coordinates and time coordinates includes the following steps:

[0013] Upper limit of the mass flow rate m of the gas source The following formula is set:

[0014]

[0015] Where T0 is the reference temperature and T is the current temperature. k represents the upper limit of the mass flow rate of the gas source at the reference temperature T0. s To reflect A constant that reflects the degree of change of T;

[0016] The failure probability of the gas pipeline is set as follows:

[0017] λ gl =λ gl0 +k gl (T-T0)

[0018] Where λ gl Let λ be the probability of gas pipeline failure. gl0 k represents the failure probability of the pipeline at the reference temperature T0. gl To reflect λ gl A constant that reflects the degree of change of T;

[0019] The mass flow rate for a typical gas load is set as follows:

[0020] m gd =m gd0 +k gd (T-T0)

[0021] Where m gd For conventional gas load mass flow rate, m gd0 k represents the upper limit of the mass flow rate of the pipeline at the reference temperature T0. gd A constant that reflects the degree to which m changes with T;

[0022] The failure probability of power transmission lines is set as follows:

[0023]

[0024] Where λ el Let v be the probability of a power transmission line failure, and v be the current wind speed. dHere, l is a speed reference, l is the line length, and a and b are constants derived from line specifications and actual operating data.

[0025] The active power load of the electrical load is set as follows:

[0026] P′=P ed0 +k ed (T-T0)

[0027] Where P′ is the active load, P ed0 For the active load at the reference temperature T0, k ed It is a constant that reflects the degree of change of P′ with T.

[0028] Optionally, setting the state variable over-limit index for the operation of the pneumatic-electric coupling system includes the following steps:

[0029] Set the over-limit index PI for the node pressure and bus voltage. node as follows:

[0030]

[0031] Where i represents the node pressure and bus voltage number, x i For node pressure and bus voltage, To constrain its upper limit, x i As a lower bound constraint, w i It is a weighting coefficient;

[0032] Set the over-limit index PI for the pipeline flow rate and line power. branch as follows:

[0033]

[0034] Where l represents the pipe flow rate and line power number, x l For pipeline flow rate and line power, For x l The upper limit constraint, w l These are the weighting coefficients;

[0035] Set the over-limit index PI for the load loss. load as follows:

[0036]

[0037] Where j is the node number, For the expected load of node j, x j w represents the actual load of node j. j Let ε be the weight coefficient of node j, and ε be the scaling factor.

[0038] Optionally, determining the system safety indicators based on the state variable limit violation index includes the following steps:

[0039] The over-limit index PI of the node pressure and bus voltage. node Pipeline flow rate and line power exceeding limits (PI) branch and the over-limit index PI of load loss load The weighted sum is as follows:

[0040] PI = w n *PI node +w b *PI branch +w d *PI load

[0041] Among them, w n w b w d These are the weighting coefficients corresponding to nodes, branches, and load shedding indicators, respectively, and PI is the system safety indicator, thus determining the system safety indicator.

[0042] Optionally, determining the system risk indicators based on the system security indicators includes the following steps:

[0043] Let the failure probability of branch i in the gas-electric coupling system be λ. i Then we have:

[0044]

[0045] Where s represents the state of the gas-electric coupling system, and P(s) is the probability of state s occurring;

[0046] Based on the system safety index PI and the probability P(s) of condition s occurring, determine the system risk index:

[0047]

[0048] Wherein, RI(t) is the system risk index, s represents the state of the gas-electric coupling system, t is the time coordinate, PI(s,t) is the system safety index of the system at time t under state s, and P(s) is the probability of state s occurring.

[0049] Secondly, embodiments of the present invention provide a risk assessment device for a pneumatic-electric coupling system, comprising:

[0050] The parameter and boundary condition determination module is used to set the plane coordinates (x, y) and time coordinates t of each component in the gas-electric coupling system; and to determine the parameters and boundary conditions of the gas-electric coupling system at any time according to the temperature T and wind speed v corresponding to different plane coordinates and time coordinates.

[0051] The limit-crossing indicator setting module is used to perform comprehensive energy flow calculations based on the parameters and boundary conditions of the gas-electric coupling system at any given time, to obtain the state variables of the gas-electric coupling system, wherein the state variables include node pressure, pipeline flow, bus voltage, line power, and load shedding; and to set the limit-crossing indicators for the state variables of the gas-electric coupling system.

[0052] The risk assessment module is used to determine system safety indicators based on the state quantity limit exceedance indicators; determine system risk indicators based on the system safety indicators; and perform risk assessment on the gas-electric coupling system based on the system risk indicators.

[0053] Optionally, the parameter and boundary condition determination module is specifically used for:

[0054] Set the planar coordinates (x, y) and time coordinates t for each element in the gas-electric coupling system;

[0055] Upper limit of the mass flow rate m of the gas source The following formula is set:

[0056]

[0057] Where T0 is the reference temperature and T is the current temperature. k represents the upper limit of the mass flow rate of the gas source at the reference temperature T0. s To reflect A constant that reflects the degree of change of T;

[0058] The failure probability of the gas pipeline is set as follows:

[0059] λ gl =λ gl0 +k gl (T-T0)

[0060] Where λ gl Let λ be the probability of gas pipeline failure. gl0 k represents the failure probability of the pipeline at the reference temperature T0. gl To reflect λ gl A constant that reflects the degree of change of T;

[0061] The mass flow rate for a typical gas load is set as follows:

[0062] m gd =m gd0 +k gd (T-T0)

[0063] Where m gd For conventional gas load mass flow rate, m gd0k represents the upper limit of the mass flow rate of the pipeline at the reference temperature T0. gd A constant that reflects the degree to which m changes with T;

[0064] The failure probability of power transmission lines is set as follows:

[0065]

[0066] Where λ el Let v be the probability of a power transmission line failure, and v be the current wind speed. d Here, l is a speed reference, l is the line length, and a and b are constants derived from line specifications and actual operating data.

[0067] The active power load of the electrical load is set as follows:

[0068] P′=P ed0 +k ed (T-T0)

[0069] Where P′ is the active load, P ed0 For the active load at the reference temperature T0, k ed It is a constant that reflects the degree of change of P′ with T.

[0070] Optionally, the over-limit indicator setting module is specifically used for:

[0071] Based on the parameters and boundary conditions of the gas-electric coupling system at any given time, a comprehensive energy flow calculation is performed to obtain the state variables of the gas-electric coupling system, which include node pressure, pipeline flow rate, bus voltage, line power, and load shedding.

[0072] Set the over-limit index PI for the node pressure and bus voltage. node as follows:

[0073]

[0074] Where i represents the node pressure and bus voltage number, x i For node pressure and bus voltage, To constrain its upper limit, x i As a lower bound constraint, w i It is a weighting coefficient;

[0075] Set the over-limit index PI for the pipeline flow rate and line power. branch as follows:

[0076]

[0077] Where l represents the pipe flow rate and line power number, x lFor pipeline flow rate and line power, For x l The upper limit constraint, w l These are the weighting coefficients;

[0078] Set the over-limit index PI for the load loss. load as follows:

[0079]

[0080] Where j is the node number, For the expected load of node j, x j w represents the actual load of node j. j Let ε be the weight coefficient of node j, and ε be the scaling factor.

[0081] Optionally, the risk assessment module is specifically used for:

[0082] The over-limit index PI of the node pressure and bus voltage. node Pipeline flow rate and line power exceeding limits (PI) branch and the over-limit index PI of load loss load The weighted sum is as follows:

[0083] PI = w n *PI node +w b *PI branch +w d *PI load

[0084] Among them, w n w b w d These are the weighting coefficients corresponding to nodes, branches, and load loss indicators, respectively, and PI is the system safety indicator, thus determining the system safety indicator;

[0085] Let the failure probability of branch i in the gas-electric coupling system be λ. i Then we have:

[0086]

[0087] Where s represents the state of the gas-electric coupling system, and P(s) is the probability of state s occurring;

[0088] Based on the system safety index PI and the probability P(s) of condition s occurring, determine the system risk index:

[0089]

[0090] Wherein, RI(t) is the system risk index, s represents the state of the gas-electric coupling system, t is the time coordinate, PI(s,t) is the system safety index of the system at time t under state s, and P(s) is the probability of state s occurring.

[0091] Based on the same inventive concept, embodiments of the present invention also provide an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the aforementioned risk assessment method for a gas-electric coupling system.

[0092] Based on the same inventive concept, embodiments of the present invention also provide a computer storage medium storing computer-executable instructions, which, when executed, implement the aforementioned risk assessment method for gas-electric coupling systems.

[0093] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0094] By incorporating wind speed and temperature into the component parameters of a gas-electric coupling system, various indicators for measuring system safety were designed. Based on the probability distribution of system conditions, risk indicators for the system were proposed, and a risk assessment method for gas-electric coupling systems considering weather factors was constructed. This method can effectively identify the weak links of the gas-electric coupling system under extreme weather conditions, predict the changing trend of system operation risk over time, and conduct effective and accurate assessment of system risk under extreme weather conditions. It has important reference value for ensuring the safe operation of power systems under extreme weather conditions.

[0095] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0096] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0097] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0098] Figure 1 This is a flowchart of the risk assessment method for the gas-electric coupling system in an embodiment of the present invention;

[0099] Figure 2 This is a schematic diagram of the gas-electric coupling system structure in an embodiment of the present invention;

[0100] Figure 3 This is a graph showing the node pressure variation of the natural gas system in an embodiment of the present invention.

[0101] Figure 4 This is a schematic diagram illustrating the changes in system security indicators over time in an embodiment of the present invention;

[0102] Figure 5 This is a graph showing the change of system risk indicators over time in an embodiment of the present invention;

[0103] Figure 6 This is a schematic diagram of the structure of the risk assessment device for the gas-electric coupling system in an embodiment of the present invention;

[0104] Figure 7 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0105] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0106] To address the problems existing in the prior art, embodiments of the present invention provide a method, apparatus, electronic device, and storage medium for risk assessment of a gas-electric coupling system.

[0107] Embodiment 1 of the present invention provides a risk assessment method for a gas-electric coupling system, the process of which is as follows: Figure 1 As shown, it includes the following steps:

[0108] Step S101: Set the plane coordinates (x, y) and time coordinates t of each component in the gas-electric coupling system; determine the parameters and boundary conditions of the gas-electric coupling system at any time according to the temperature T and wind speed v corresponding to different plane coordinates and time coordinates.

[0109] For example, establish a Cartesian coordinate system and write down the plane coordinates (x, y) of each component in the system. Consider two weather variables, temperature T and wind speed v. Let t be time, then (T, v) is a function of (x, y, t). In addition to the original parameters, set the correlation between each component and (T, v).

[0110] Optionally, determining the parameters and boundary conditions of the gas-electric coupling system at any given time based on the temperature T and wind speed v corresponding to different planar coordinates and time coordinates includes the following steps:

[0111] For a given gas source, its pressure p is constant, and the upper limit of the gas source's mass flow rate m is... The following formula is set:

[0112]

[0113] Where T0 is the reference temperature and T is the current temperature. k represents the upper limit of the mass flow rate of the gas source at the reference temperature T0. s To reflect A constant that reflects the degree of change of T;

[0114] For gas pipelines, the failure probability changes with temperature. The failure probability of a gas pipeline is set as follows:

[0115] λ gl =λ gl0 +k gl (T-T0)

[0116] Where λ gl Let λ be the probability of gas pipeline failure. gl0 k represents the failure probability of the pipeline at the reference temperature T0. gl To reflect λ gl A constant that reflects the degree of change of T;

[0117] The mass flow rate for a typical gas load is set as follows:

[0118] m gd =m gd0 +k gd (T-T0)

[0119] Where m gd For conventional gas load mass flow rate, m gd0 k represents the upper limit of the mass flow rate of the pipeline at the reference temperature T0. gd A constant that reflects the degree to which m changes with T;

[0120] The failure probability of power transmission lines is set as follows:

[0121]

[0122] Where λ el Let v be the probability of a power transmission line failure, and v be the current wind speed. d Here, l is a speed reference, l is the line length, and a and b are constants derived from line specifications and actual operating data.

[0123] The active power load of the electrical load is set as follows:

[0124] P′=P ed0 +k ed (T-T0)

[0125] Where P′ is the active load, Ped0 For the active load at the reference temperature T0, k ed It is a constant that reflects the degree of change of P′ with T.

[0126] As shown in step S101, for any time t, the gas-electric coupling system has definite parameters and boundary conditions, thus enabling comprehensive energy flow calculation. The calculations yield various state variables of the system operation, including node pressures and pipeline flow rates in the natural gas network, and bus voltages and line power in the power system.

[0127] For a "normal" gas-electric coupling system, all state variables of the system operation must be kept within a certain range. Therefore, the condition of system components can be reflected by setting limit indicators.

[0128] Step S102: Based on the parameters and boundary conditions of the gas-electric coupling system at any given time, perform comprehensive energy flow calculations to obtain the state variables of the gas-electric coupling system, wherein the state variables include node pressure, pipeline flow rate, bus voltage, line power, and load shedding.

[0129] Set the state quantity over-limit indicators for the operation of the gas-electric coupling system;

[0130] Optionally, setting the state variable over-limit index for the operation of the pneumatic-electric coupling system includes the following steps:

[0131] Set the over-limit index PI for the node pressure and bus voltage. node as follows:

[0132]

[0133] Where i represents the node pressure and bus voltage number, x i For node pressure and bus voltage, To constrain its upper limit, x i As a lower bound constraint, w i It is a weighting coefficient;

[0134] Set the over-limit index PI for the pipeline flow rate and line power. branch as follows:

[0135]

[0136] Where l represents the pipe flow rate and line power number, x l For pipeline flow rate and line power, For x l The upper limit constraint, w l These are the weighting coefficients;

[0137] Set the over-limit index PI for the load loss. load as follows:

[0138]

[0139] Where j is the node number, For the expected load of node j, x j w represents the actual load of node j. j Let ε be the weight coefficient of node j, and ε be the scaling factor.

[0140] In setting the above-mentioned state variable limit indicators, weather factors (T, v) either change the system's boundary conditions, thus affecting the system's operating variables, or alter the parameters in the limit indicators. When the system's (T, v) distribution changes, the results of each item in the above-mentioned state variable limit indicators usually change; therefore, the system's safety index PI is a function of time t. When the system's condition (whether a fault occurs, where the fault occurs) is different, the system's topology and parameters will also be different, which will also affect the energy flow calculation results. Therefore, the system's safety index PI is also a function of the system condition s, i.e., PI = PI(s, t).

[0141] Step S103: Determine system safety indicators based on the state quantity limit exceedance indicators; determine system risk indicators based on the system safety indicators; and conduct a risk assessment of the gas-electric coupling system based on the system risk indicators.

[0142] Optionally, determining the system safety indicators based on the state variable limit violation index includes the following steps:

[0143] The over-limit index PI of the node pressure and bus voltage. node Pipeline flow rate and line power exceeding limits (PI) branch and the over-limit index PI of load loss load The weighted sum is as follows:

[0144] PI = w n *PI node +w b *PI branch +w d *PI load

[0145] Among them, w n w b w d These are the weighting coefficients corresponding to nodes, branches, and load shedding indicators, respectively, and PI is the system safety indicator, thus determining the system safety indicator.

[0146] Optionally, determining the system risk indicators based on the system security indicators includes the following steps:

[0147] Let the failure probability of branch i in the gas-electric coupling system be λ. i Then we have:

[0148]

[0149] Where s represents the state of the gas-electric coupling system, and P(s) is the probability of state s occurring;

[0150] Based on the system safety index PI and the probability P(s) of condition s occurring, determine the system risk index:

[0151]

[0152] Wherein, RI(t) is the system risk index, s represents the state of the gas-electric coupling system, t is the time coordinate, PI(s,t) is the system safety index of the system at time t under state s, and P(s) is the probability of state s occurring.

[0153] For example, with Figure 2 Taking the pneumatic-electric coupling system shown in the figure as an example, Represents the gas source, m in Represents the gas source flow rate injection, Represents the natural gas node and its number. Represents a compressor. Represents natural gas pipelines and their numbers, m G1 Represents the load and number of the gas turbine unit, m L1 Represents conventional natural gas loads and their designations, P d1 This represents the electrical load and its number at the corresponding node. Represents the generator and its number. Represents the power busbars and their numbers. V represents the power transmission line and its number, and Vδ represents the balancing node.

[0154] Figure 2 The position coordinates of each node are shown in Table 1.

[0155] Table 1. Location coordinates of each node

[0156]

[0157] In this embodiment, it is assumed that the low-temperature region traverses the entire system at a speed of 0.6 km / min along the positive X-axis. The temperature at each point in the system is 300 K when unaffected by the low temperature, while the temperature at the low-temperature center is 280 K. The attenuation constant of the low temperature with distance is 0.5. For a point with x-coordinate, its temperature change with time t can be expressed as:

[0158] T(x, t) = 300 - 20e -0.5|x-0.6t| (K)

[0159] Wind speed v is also a function of x and t, and its expression is similar to the temperature formula above, let it be...

[0160] v(x,t) = 5 + 10e -0.5|x-0.6t| (m / s)

[0161] Temperature and wind speed can affect a number of parameters, including the upper limit of the mass flow rate of the gas source, the probability of pipeline failure, the flow rate of the conventional gas load, the probability of power transmission line failure, and the power load, which in turn affect the following results.

[0162] The calculations illustrate the changes in various state variables over time when the system is fault-free, including nodal pressures and pipeline flow rates in the natural gas system, and bus voltages and branch power in the power system. The calculation results are presented here using nodal pressures in the natural gas system as an example. Figure 3 The curves showing the pressure changes at nodes in the natural gas system are shown. The horizontal axis represents time (in minutes), and the vertical axis represents node pressure (in bars).

[0163] In addition, energy flow calculations need to be performed on the system under each fault condition to obtain the changes in variables such as node pressure and pipeline flow of the natural gas system, and bus voltage and branch power of the power system over time under different conditions. The process is similar to that above and will not be elaborated here.

[0164] Faults 1-8 in the gas pipeline network and faults 1-4 in the power grid transmission lines are numbered sequentially as Fault 1-12. Based on the steady-state energy flow calculation results, the variation of the safety index PI(s,t) of each fault over time is obtained as follows: Figure 4 As shown, the horizontal axis represents time in minutes, the vertical axis represents the fault number, and the right-hand scale represents the safety index PI(s,t) value; the larger the value, the darker the color. Figure 4 The changes in system safety under each anticipated fault are presented. It can be seen that for the natural gas system, the safety index is highest under pipeline 1 failure, as not only does the natural gas system lose all loads, but the power system also loses two power sources, further amplifying the impact of the fault. For the power system, the safety index is highest under line 2 failure, with two significant peaks observed during the extreme weather event, which is closely related to the power system topology. It can also be seen that regardless of the fault, the system safety index reaches its maximum at the 34-minute mark. This is because at this time, the extreme weather simultaneously affects four loads, including two natural gas loads and two power loads, the largest number, thus having the greatest impact on system safety.

[0165] and Figure 4 The corresponding system risk indicators are as follows Figure 5As shown in the figure, the horizontal axis represents time in minutes, and the vertical axis represents system risk indicators. Figure 5 The changes in the overall system risk index considering the probability of each anticipated failure are presented. It can be seen that the highest system risk occurs around 4 minutes, followed by 34 minutes. Figure 4 The conclusions differ slightly. This is because, around 4 minutes, although weather factors have little impact on the gas and electricity load, a larger number of branches are affected at this time, resulting in a higher probability of system failure and a greater overall risk. This indicates that the safety indicators under a single anticipated failure are not the same as the overall system risk indicators. In safety analysis, it is necessary to clarify their respective physical meanings in order to more accurately assess the risk.

[0166] In the above method of this embodiment, by incorporating wind speed and temperature into the component parameters of the gas-electric coupling system, various indicators for measuring system safety are designed, and risk indicators for the system are proposed based on the probability distribution of system conditions. A risk assessment method for gas-electric coupling systems that considers weather factors is constructed, which can effectively identify the weak links of the gas-electric coupling system under extreme weather conditions, predict the changing trend of system operation risk over time, and effectively and accurately assess system risk under extreme weather conditions. This has important reference value for ensuring the safe operation of the power system under extreme weather conditions.

[0167] Embodiment 2 of the present invention provides a risk assessment device for a pneumatic-electric coupling system, the structure of which is as follows: Figure 7 As shown, it includes:

[0168] The parameter and boundary condition determination module 101 is used to set the plane coordinates (x, y) and time coordinates t of each element in the gas-electric coupling system; and to determine the parameters and boundary conditions of the gas-electric coupling system at any time according to the temperature T and wind speed v corresponding to different plane coordinates and time coordinates.

[0169] The limit-crossing indicator setting module 102 is used to perform comprehensive energy flow calculation based on the parameters and boundary conditions of the gas-electric coupling system at any given time, to obtain the state variables of the gas-electric coupling system, wherein the state variables include node pressure, pipeline flow, bus voltage, line power and load shedding; and to set the limit-crossing indicators of the state variables of the gas-electric coupling system.

[0170] The risk assessment module 103 is used to determine system safety indicators based on the state quantity limit exceedance indicators; determine system risk indicators based on the system safety indicators; and perform risk assessment on the gas-electric coupling system based on the system risk indicators.

[0171] Optionally, the parameter and boundary condition determination module is specifically used for:

[0172] Set the planar coordinates (x, y) and time coordinates t for each element in the gas-electric coupling system;

[0173] Upper limit of the mass flow rate m of the gas source The following formula is set:

[0174]

[0175] Where T0 is the reference temperature and T is the current temperature. k represents the upper limit of the mass flow rate of the gas source at the reference temperature T0. s To reflect A constant that reflects the degree of change of T;

[0176] The failure probability of the gas pipeline is set as follows:

[0177] λ gl =λ gl0 +k gl (T-T0)

[0178] Where λ gl Let λ be the probability of gas pipeline failure. gl0 k represents the failure probability of the pipeline at the reference temperature T0. gl To reflect λ gl A constant that reflects the degree of change of T;

[0179] The mass flow rate for a typical gas load is set as follows:

[0180] m gd =m gd0 +k gd (T-T0)

[0181] Where m gd For conventional gas load mass flow rate, m gd0 k represents the upper limit of the mass flow rate of the pipeline at the reference temperature T0. gd A constant that reflects the degree to which m changes with T;

[0182] The failure probability of power transmission lines is set as follows:

[0183]

[0184] Where λ el Let v be the probability of a power transmission line failure, and v be the current wind speed. d Here, l is a speed reference, l is the line length, and a and b are constants derived from line specifications and actual operating data.

[0185] The active power load of the electrical load is set as follows:

[0186] P′=P ed0 +k ed(T-T0)

[0187] Where P′ is the active load, P ed0 For the active load at the reference temperature T0, k ed It is a constant that reflects the degree of change of P′ with T.

[0188] Optionally, the over-limit indicator setting module is specifically used for:

[0189] Based on the parameters and boundary conditions of the gas-electric coupling system at any given time, a comprehensive energy flow calculation is performed to obtain the state variables of the gas-electric coupling system, which include node pressure, pipeline flow rate, bus voltage, line power, and load shedding.

[0190] Set the over-limit index PI for the node pressure and bus voltage. node as follows:

[0191]

[0192] Where i represents the node pressure and bus voltage number, x i For node pressure and bus voltage, To constrain its upper limit, x i As a lower bound constraint, w i It is a weighting coefficient;

[0193] Set the over-limit index PI for the pipeline flow rate and line power. branch as follows:

[0194]

[0195] Where l represents the pipe flow rate and line power number, x l For pipeline flow rate and line power, For x l The upper limit constraint, w l These are the weighting coefficients;

[0196] Set the over-limit index PI for the load loss. load as follows:

[0197]

[0198] Where j is the node number, For the expected load of node j, x j w represents the actual load of node j. j Let ε be the weight coefficient of node j, and ε be the scaling factor.

[0199] Optionally, the risk assessment module is specifically used for:

[0200] The over-limit index PI of the node pressure and bus voltage. node Pipeline flow rate and line power exceeding limits (PI) branch and the over-limit index PI of load loss load The weighted sum is as follows:

[0201] PI = w n *PI node +w b *PI branch +w d *PI load

[0202] Among them, w n w b w d These are the weighting coefficients corresponding to nodes, branches, and load loss indicators, respectively, and PI is the system safety indicator, thus determining the system safety indicator;

[0203] Let the failure probability of branch i in the gas-electric coupling system be λ. i Then we have:

[0204]

[0205] Where s represents the state of the gas-electric coupling system, and P(s) is the probability of state s occurring;

[0206] Based on the system safety index PI and the probability P(s) of condition s occurring, determine the system risk index:

[0207]

[0208] Wherein, RI(t) is the system risk index, s represents the state of the gas-electric coupling system, t is the time coordinate, PI(s,t) is the system safety index of the system at time t under state s, and P(s) is the probability of state s occurring.

[0209] A risk assessment is conducted on the gas-electric coupling system based on the system risk indicators.

[0210] For example, with Figure 2 Taking the pneumatic-electric coupling system shown in the figure as an example, Represents the gas source, m in Represents the gas source flow rate injection, Represents the natural gas node and its number. Represents a compressor. Represents natural gas pipelines and their numbers, m G1 Represents the load and number of the gas turbine unit, m L1 Represents conventional natural gas loads and their designations, P d1This represents the electrical load and its number at the corresponding node. Represents the generator and its number. Represents the power busbars and their numbers. V represents the power transmission line and its number, and Vδ represents the balancing node.

[0211] Figure 2 The position coordinates of each node are shown in Table 1.

[0212] Table 1. Location coordinates of each node

[0213]

[0214] In this embodiment, it is assumed that the low-temperature region traverses the entire system at a speed of 0.6 km / min along the positive X-axis. The temperature at each point in the system is 300 K when unaffected by the low temperature, while the temperature at the low-temperature center is 280 K. The attenuation constant of the low temperature with distance is 0.5. For a point with x-coordinate, its temperature change with time t can be expressed as:

[0215] T(x, t) = 300 - 20e -0.5|x-0.6t| (K)

[0216] Wind speed v is also a function of x and t, and its expression is similar to the temperature formula above, let it be...

[0217] v(x,t) = 5 + 10e -0.5|x-0.6t| (m / s)

[0218] Temperature and wind speed can affect a number of parameters, including the upper limit of the mass flow rate of the gas source, the probability of pipeline failure, the flow rate of the conventional gas load, the probability of power transmission line failure, and the power load, which in turn affect the following results.

[0219] The calculations illustrate the changes in various state variables over time when the system is fault-free, including nodal pressures and pipeline flow rates in the natural gas system, and bus voltages and branch power in the power system. The calculation results are presented here using nodal pressures in the natural gas system as an example. Figure 3 The curves showing the pressure changes at nodes in the natural gas system are shown. The horizontal axis represents time (in minutes), and the vertical axis represents node pressure (in bars).

[0220] In addition, energy flow calculations need to be performed on the system under each fault condition to obtain the changes in variables such as node pressure and pipeline flow of the natural gas system, and bus voltage and branch power of the power system over time under different conditions. The process is similar to that above and will not be elaborated here.

[0221] Faults 1-8 in the gas pipeline network and faults 1-4 in the power grid transmission lines are numbered sequentially as Fault 1-12. Based on the steady-state energy flow calculation results, the variation of the safety index PI(s,t) of each fault over time is obtained as follows: Figure 4 As shown, the horizontal axis represents time in minutes, the vertical axis represents the fault number, and the right-hand scale represents the safety index PI(s,t) value; the larger the value, the darker the color. Figure 4 The changes in system safety under each anticipated fault are presented. It can be seen that for the natural gas system, the safety index is highest under pipeline 1 failure, as not only does the natural gas system lose all loads, but the power system also loses two power sources, further amplifying the impact of the fault. For the power system, the safety index is highest under line 2 failure, with two significant peaks observed during the extreme weather event, which is closely related to the power system topology. It can also be seen that regardless of the fault, the system safety index reaches its maximum at the 34-minute mark. This is because at this time, the extreme weather simultaneously affects four loads, including two natural gas loads and two power loads, the largest number, thus having the greatest impact on system safety.

[0222] and Figure 4 The corresponding system risk indicators are as follows Figure 5 As shown in the figure, the horizontal axis represents time in minutes, and the vertical axis represents system risk indicators. Figure 5 The changes in the overall system risk index considering the probability of each anticipated failure are presented. It can be seen that the highest system risk occurs around 4 minutes, followed by 34 minutes. Figure 4 The conclusions differ slightly. This is because, around 4 minutes, although weather factors have little impact on the gas and electricity load, a larger number of branches are affected at this time, resulting in a higher probability of system failure and a greater overall risk. This indicates that the safety indicators under a single anticipated failure are not the same as the overall system risk indicators. In safety analysis, it is necessary to clarify their respective physical meanings in order to more accurately assess the risk.

[0223] In this embodiment, by incorporating wind speed and temperature into the component parameters of the gas-electric coupling system, various indicators for measuring system safety were designed. Based on the probability distribution of system conditions, risk indicators for the system were proposed, and a risk assessment device for the gas-electric coupling system considering weather factors was constructed. This device can effectively identify the weak links of the gas-electric coupling system under extreme weather conditions, predict the changing trend of system operation risk over time, and effectively and accurately assess system risk under extreme weather conditions. It has important reference value for ensuring the safe operation of the power system under extreme weather conditions.

[0224] Based on the same inventive concept, embodiments of the present invention also provide an electronic device, the structure of which is as follows: Figure 7 As shown, it includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned risk assessment method for gas-electric coupling systems.

[0225] Based on the same inventive concept, embodiments of the present invention also provide a computer storage medium storing computer-executable instructions, which, when executed, implement the aforementioned risk assessment method for gas-electric coupling systems.

[0226] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

Claims

1. A method for risk assessment of a gas-electric coupling system, characterized in that, The method comprises the following steps: Setting plane coordinates and time coordinates of each element in a gas-electricity coupling system; the gas-electricity coupling system comprises a natural gas system and an electricity system; the natural gas system and the electricity system are coupled through a gas-fired generator set; According to temperatures T and wind speeds v corresponding to different plane coordinates and time coordinates, determining parameters and boundary conditions of the gas-electricity coupling system at any time; the temperature influences a failure probability of a gas transmission pipeline; the wind speed influences a failure probability of an electricity transmission line; According to the determined parameters and boundary conditions of the gas-electricity coupling system at any time, performing comprehensive energy flow calculation to obtain state quantities of operation of the gas-electricity coupling system, wherein the state quantities comprise node pressure, pipeline flow, bus voltage, line power and loss of load; Setting out-of-limit indicators of the state quantities of operation of the gas-electricity coupling system: out-of-limit indicators of node pressure and bus voltage, out-of-limit indicators of pipeline flow and line power, and an out-of-limit indicator of loss of load; Summing the out-of-limit indicators of node pressure and bus voltage, the out-of-limit indicators of pipeline flow and line power, and the out-of-limit indicator of loss of load to determine a system safety indicator; According to the system safety indicator, determining a system risk indicator, and according to the system risk indicator, performing risk assessment on the gas-electricity coupling system.

2. The method of claim 1, wherein, The step of determining the parameters and boundary conditions of the gas-electricity coupling system at any time according to the temperatures T and the wind speeds v corresponding to different plane coordinates and time coordinates comprises the following steps: Mass flow rate of the gas source Upper limit of the above The following equation is set: wherein is a reference temperature, is a current temperature, is a reference temperature an upper limit of the mass flow rate of the lower gas source, is a constant reflecting a degree of change in the temperature The failure probability of the gas transmission pipeline is set as follows: wherein is the failure probability of the gas transmission pipeline, is the reference temperature is the failure probability of the lower pipeline, is a constant reflecting the degree of change in the temperature The mass flow of the conventional gas load is set as follows: wherein is the normal gas load mass flow rate, is the reference temperature is the upper limit of the mass flow rate of the down pipe, is a constant reflecting the degree of change in the degree of change in The failure probability of the electricity transmission line is set as follows: wherein is the probability of a power transmission line fault, is the current wind speed, is a speed reference, is the line length, , are constants derived from line specifications and actual operating data; The active load of the electricity load is set as follows: wherein is the active load, is the reference temperature is the active load at the reference temperature, is a constant reflecting the degree of change in the active load.

3. The method of claim 1, wherein, The step of setting the out-of-limit indicators of the state quantities of operation of the gas-electricity coupling system comprises the following steps: Setting the out-of-limit indicators of the node pressure and bus voltage As follows: where i is the node pressure and bus voltage number, is the node pressure and bus voltage, is its upper bound constraint, is its lower bound constraint, is a weight coefficient; Setting out-of-limit indicators for pipe flow and line power As follows: wherein, l is the pipeline flow and line power number, is the pipeline flow and line power, is the upper bound constraint, is the weight coefficient; setting the out-of-limit indicator of the loss of load as follows: wherein, is the node number, is the node expected load, is the node actual load, is the node weighting factor, is the expansion factor.

4. The method of claim 3, wherein, The step of determining the system safety indicator according to the out-of-limit indicators of the state quantities comprises the following steps: out-of-limit indicators of the node stress and bus voltage out-of-limit indicators of the pipe flow and line power out-of-limit indicators of loss of load are weighted and summed as follows: wherein, , , are weight coefficients corresponding to the node, branch and loss-of-load indicators, respectively, PI is the system security indicator, thereby determining the system security indicator.

5. The method of claim 1, wherein, The step of determining the system risk indicator according to the system safety indicator comprises the following steps: Let the failure probability of the gas-electric coupling system branch be then there is: wherein s represents a condition of the gas-electric coupling system, is a condition probability of occurrence; According to the system safety indicator PI and the condition The probability of occurrence , determine the system risk indicator: wherein, is the system risk indicator, s represents the condition of the gas-electric coupling system, t is a time coordinate, is the condition The system below is in time The system safety indicator, is the condition The probability of occurrence.

6. An aerotomic system risk assessment device, comprising: It comprises: A parameter and boundary condition determination module, configured to set plane coordinates and time coordinates of each element in a gas-electricity coupling system; and determine parameters and boundary conditions of the gas-electricity coupling system at any time according to temperatures T and wind speeds v corresponding to different plane coordinates and time coordinates; the gas-electricity coupling system comprises a natural gas system and an electricity system; the natural gas system and the electricity system are coupled through a gas-fired generator set; the temperature influences a failure probability of a gas transmission pipeline; and the wind speed influences a failure probability of an electricity transmission line; An out-of-limit indicator setting module, configured to perform comprehensive energy flow calculation according to the determined parameters and boundary conditions of the gas-electricity coupling system at any time to obtain state quantities of operation of the gas-electricity coupling system, wherein the state quantities comprise node pressure, pipeline flow, bus voltage, line power and loss of load; The out-of-limit indicators of the state quantities of operation of the gas-electricity coupling system are set as follows: out-of-limit indicators of node pressure and bus voltage, out-of-limit indicators of pipeline flow and line power, and an out-of-limit indicator of loss of load; The risk assessment module is configured to: weight and sum up the out-of-limit indexes of node pressure and bus voltage, the out-of-limit indexes of pipeline flow and line power, and the out-of-limit indexes of loss of load to determine a system safety index; determine a system risk index according to the system safety index; and perform risk assessment on the gas-electricity coupling system according to the system risk index.

7. The apparatus of claim 6, wherein, The parameter and boundary condition determination module is specifically configured to: Mass flow rate of the gas source Upper limit The following equation is set: wherein is a reference temperature, is a current temperature, is a reference temperature an upper limit of the mass flow rate of the lower gas source, is a constant reflecting the degree of change in the temperature The failure probability of the gas transmission pipeline is set as follows: wherein is the failure probability of the gas transmission pipeline, is the reference temperature is the failure probability of the lower pipeline, is a constant reflecting the degree of change in the temperature The mass flow of the conventional gas load is set as follows: wherein is the normal gas load mass flow rate, is the reference temperature is the upper limit of the mass flow rate of the lower pipe, is a constant reflecting the degree of change in the degree of change in The failure probability of the power transmission line is set as follows: wherein is the probability of a power transmission line fault, is the current wind speed, is a speed reference, is the line length, , are constants derived from line specifications and actual operating data; The active load of the power load is set as: wherein is the active load, is the reference temperature is the active load at the reference temperature, is a constant reflecting the degree of change in the active load.

8. The apparatus of claim 6, wherein, The out-of-limit index setting module is specifically configured to: According to the determined parameters and boundary conditions of the gas-electricity coupling system at any time, comprehensive energy flow calculation is performed to obtain state quantities of the operation of the gas-electricity coupling system, wherein the state quantities include node pressure, pipeline flow, bus voltage, line power and loss of load. Setting the out-of-limit indicators of the node pressure and bus voltage As follows: where i is the node pressure and bus voltage number, is the node pressure and bus voltage, is its upper bound constraint, is its lower bound constraint, is a weight coefficient; Setting out-of-limit indicators for pipe flow and line power As follows: wherein, l is the pipeline flow and line power number, is the pipeline flow and line power, is the upper bound constraint, is the weight coefficient; setting the out-of-limit indicator of the loss of load as follows: wherein, is the node number, is the node expected load, is the node actual load, is the node weighting factor, is the amplification factor.

9. The apparatus of claim 8, wherein, The risk assessment module is specifically configured to: out-of-limit indicators of the node stress and bus voltage out-of-limit indicators of the pipe flow and line power out-of-limit indicators of the load loss are weighted and summed as follows: wherein, , , are weight coefficients corresponding to the nodes, branches, and loss-of-load indicators, respectively, PI is the system safety indicator, thereby determining the system safety indicator. Let the failure probability of the gas-electric coupling system branch be then there is: wherein s represents a condition of the gas-electric coupling system, is a condition probability of occurrence; According to the system safety indicator PI and the condition The probability of occurrence , determine the system risk indicator: wherein, is the system risk indicator, s represents the condition of the gas-electric coupling system, t is the time coordinate, is the condition The system under discussion is in time the system safety indicator, is the condition the probability of occurrence.

10. An electronic device, comprising: The method comprises the following steps: The memory, the processor and the computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to realize the gas-electricity coupling system risk assessment method in any one of claims 1-5.

11. A computer storage medium, characterized in that, The computer storage medium stores computer executable instructions, and the computer executable instructions are executed to realize the gas-electricity coupling system risk assessment method in any one of claims 1-5.

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