Method and system for optimizing operation of integrated energy system and verifying stability of electric energy flow

Abstract

The invention discloses a comprehensive energy system optimization operation and electric energy flow stability verification method and system. The method comprises the steps that the energy flow topology of a low-carbon city comprehensive energy system is determined; collecting electric energy flow stable operation guide rule data of the low-carbon urban integrated energy system for determining the energy flow topology; establishing an optimized operation model of the low-carbon urban comprehensive energy system, and determining an objective function of the optimized operation model; the optimized operation model of the low-carbon city integrated energy system comprises a low-carbon city integrated energy system carbon transaction cost model, a low-carbon city integrated energy system optimized operation main body model and a low-carbon city integrated energy system optimized operation constraint model; based on the optimized operation model, establishing an electric energy flow stable operation verification model of the low-carbon urban integrated energy system; and verifying the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow.

Description

Technical Field

[0001] The present invention relates to the technical field of low-carbon dispatching operation of power systems, and more specifically, to a method and system for optimizing operation of an integrated energy system and verifying the stability of electric energy flow. Background Art

[0002] Due to the development of urban energy demand, the energy pressure of the integrated energy system has increased sharply, and thus faced the problem of carbon emission management and treatment. In order to solve the high emission environmental problem caused by high energy consumption, it is urgent to adopt a carbon trading mechanism to optimize system resource allocation and promote energy conservation and emission reduction.

[0003] The carbon trading mechanism is a trading system that allows carbon emission rights to be bought and sold in the market. Since carbon assets are not commodities and have no significant development value, the commercialization characteristics of carbon emission rights can promote the optimization of energy structure, improve energy efficiency, and ultimately reduce greenhouse gas emissions. If the carbon emissions of carbon emission sources in the low-carbon city's integrated energy system are within the carbon emission quota planned by the government, the excess carbon emission quota can be allocated to the carbon trading market and participate in carbon trading. If the carbon emissions of carbon emission sources in the low-carbon city's integrated energy system exceed the carbon emission quota, the excess must be purchased from the carbon trading market. Unlike mandatory emission reductions, under the carbon trading mechanism, enterprises will actively participate in carbon emission reductions in order to maximize economic benefits.

[0004] In view of the low-carbon operation requirements of low-carbon urban integrated energy systems, it is of great significance to comprehensively consider the carbon trading mechanism and carbon trading costs for the formulation of low-carbon optimized operation strategies for cities. In addition, due to the coupling problem of power flow and thermal energy flow in modern urban integrated energy systems, considering the safe and stable operation of the power grid will become the basic requirement for the optimized operation of future low-carbon integrated energy systems.

[0005] Therefore, a technology is needed to achieve the optimized operation of the integrated energy system and the stable verification of the power flow suitable for low-carbon cities. Summary of the invention

[0006] The technical solution of the present invention provides a method and system for verifying the optimized operation of an integrated energy system and the stability of electric energy flow, so as to solve the problem of how to verify the optimized operation of an integrated energy system and the stability of electric energy flow.

[0007] In order to solve the above problems, the present invention provides a method for optimizing the operation of an integrated energy system and verifying the stability of electric energy flow, the method comprising:

[0008] Determine the energy flow topology of low-carbon urban integrated energy systems;

[0009] Collecting data on stable operation of electric energy flow of the low-carbon urban integrated energy system to determine the energy flow topology;

[0010] Establishing an optimal operation model of the low-carbon city integrated energy system and determining the objective function of the optimal operation model; the optimal operation model of the low-carbon city integrated energy system includes a carbon transaction cost model of the low-carbon city integrated energy system, an optimal operation subject model of the low-carbon city integrated energy system and an optimal operation constraint model of the low-carbon city integrated energy system;

[0011] Based on the optimized operation model, a stable operation verification model of electric energy flow of the low-carbon urban integrated energy system is established;

[0012] The electric energy flow stable operation capability is verified based on the electric energy flow stable operation verification model.

[0013] Preferably, determining the energy flow topology of the low-carbon urban integrated energy system includes:

[0014] Based on the energy supply, energy consumption and electricity load data of the low-carbon city comprehensive energy system, the energy flow topology of the low-carbon city comprehensive energy system is determined.

[0015] Preferably, the collecting of the electric energy flow stable operation guideline data of the low-carbon urban integrated energy system, wherein the electric energy flow stable operation guideline data comprises:

[0016] The upper and lower boundary values ​​of power fluctuation of electric energy flow are

[0017] The upper and lower boundary values ​​of the power flow frequency fluctuation are

[0018] Preferably, the electric energy flow stable operation verification model includes a low-carbon city integrated energy system carbon trading cost model:

[0019] The total equivalent calorific value of the low-carbon urban integrated energy system is the carbon emission quota allocated to the source unit. The carbon emission quota Q at time t is e,t for:

[0020]

[0021] Among them, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t;

[0022] The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for:

[0023]

[0024] Among them, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively, and satisfy:

[0025] γ GT =γ GB =τ·C arc ·C c ·δ oc

[0026] Among them, τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δ oc The carbon oxidation rate of coal for carbon-fired projects;

[0027] Carbon trading cost C at time t Ca,t for:

[0028] C Ca,t =α Ca (Q Act,t -Q e,t )

[0029] Among them, α Ca is the carbon trading market price.

[0030] Preferably, the electric energy flow stable operation verification model of the low-carbon city integrated energy system is established, wherein the electric energy flow stable operation verification model includes a low-carbon city integrated energy system optimization operation subject model:

[0031] The goal of the low-carbon city integrated energy system optimization operation subject model is to minimize the comprehensive operation cost of the low-carbon city integrated energy system, including energy purchase cost, operation and maintenance cost, carbon trading cost and carbon storage cost, as follows:

[0032]

[0033] Among them, f is the comprehensive operating cost of the low-carbon urban integrated energy system, T represents an operating cycle, and C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost;

[0034] The energy acquisition cost of the low-carbon urban integrated energy system is:

[0035]

[0036] in, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,t is the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively;

[0037] The carbon trading cost of the low-carbon city integrated energy system is:

[0038]

[0039] The operation and maintenance cost of the low-carbon urban integrated energy system is:

[0040]

[0041] Among them, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in the low-carbon urban integrated energy system during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in economic optimization in the low-carbon urban integrated energy system;

[0042] The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated:

[0043]

[0044] The cost of carbon sequestration is:

[0045]

[0046] Among them, η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the low-carbon city comprehensive energy system in period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture plants, ECs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

[0047] Preferably, the electric energy flow stable operation verification model of the low-carbon city integrated energy system is established, wherein the electric energy flow stable operation verification model includes an optimized operation constraint model of the low-carbon city integrated energy system:

[0048] The optimization operation constraint model of the low-carbon city comprehensive energy system includes: wind power output constraint, photovoltaic output constraint, energy balance constraint, CHP constraint, equipment energy conversion constraint, electricity consumption willingness constraint, energy storage operation constraint, and electric vehicle charging and discharging constraint;

[0049] The wind power output constraint is that the actual wind power output is often less than the predicted output:

[0050]

[0051] in, They are the actual wind power output and predicted wind power output at time t respectively;

[0052] The photovoltaic output constraint is that the actual photovoltaic output is often less than the predicted output:

[0053]

[0054] in, They are the actual photovoltaic output and predicted output at time t respectively;

[0055] The energy balance constraint is that the low-carbon city comprehensive energy system includes electric energy flow, thermal energy flow and gas energy flow, all of which must meet the energy balance constraint:

[0056]

[0057] in, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption, and GB gas consumption at time t;

[0058] Cogeneration constraints include electricity and heat generation constraints of cogeneration and gas-to-electricity and gas-to-heat constraints of gas boilers:

[0059]

[0060] in, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHB is the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC The power generation efficiency of the waste heat power generation device;

[0061] The equipment energy conversion constraint is that the conversion amount of electrical load and thermal load shall not exceed the upper and lower limits:

[0062]

[0063] in, are the minimum and maximum replacement amounts of the replaceable electric load, x are the minimum and maximum replacement amounts of the replaceable heat load respectively; ΔP t Re , ΔP t Rh They are the replaceable electric load and replaceable thermal load at time t respectively;

[0064] The power consumption willingness constraint is to define the power consumption response willingness coefficient as the difference between the constant 1 and the power consumption substitution coefficient; the power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load:

[0065]

[0066] χ ACL ≥χ ACLmin

[0067] In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin is the minimum value of the electricity consumption response willingness coefficient; is the initial load at time t, is the initial load reduction at time t, is the load that can be adjusted at time t;

[0068] Energy storage operation constraints require that energy storage equipment meet the following constraints:

[0069]

[0070] in, is the remaining capacity of the ith energy storage device at the end of the 24th hour, is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,t They are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t;

[0071] The charging and discharging constraints of electric vehicles are:

[0072]

[0073] in, They are the charging and discharging start and stop status flags of the i-th electric vehicle in time period t;

[0074] The active power transmission constraint of DC transmission is:

[0075]

[0076] in, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

[0077] Preferably, the step of establishing a stable operation verification model of electric energy flow of the low-carbon urban integrated energy system includes:

[0078] The internal energy supply and consumption unit model of the low-carbon urban comprehensive energy system is:

[0079]

[0080] Among them, G PV is the photovoltaic transfer function, k PV is the photovoltaic time coefficient, U PV is the photovoltaic DC side voltage, C PV is the photovoltaic capacitance, H PV is the photovoltaic equivalent inertia time constant, s is the Laplace operator calculated in the frequency domain, G HVDC is the high voltage DC transfer function, α HVDC is the high voltage DC droop control coefficient, T HVDC is the high voltage DC time response coefficient, G W is the fan transfer function, k df is the fan inertia response coefficient, kpf is the fan primary frequency modulation response coefficient, T ω is the rotor inertia response time constant, T β is the pitch angle response time constant, G sg is the speed regulator transfer function, G st is the turbine transfer function, T g is the speed regulator response time constant, k R is the mechanical power factor, F H is the work coefficient of the high pressure cylinder, T R is the time response coefficient of thermal power, R is the frequency modulation coefficient of thermal power, G E is the energy storage transfer function, k E is the primary frequency modulation coefficient of energy storage, T E is the time response coefficient of energy storage, G CHP is the transfer function of the combined heat and power plant, δ CHP is the primary frequency modulation coefficient of the cogeneration unit, T CHP is the time response coefficient of the cogeneration device, G RAC is the air conditioning transfer function, δ RAC is the primary frequency modulation coefficient of the air conditioner, T RAC is the air conditioning time response coefficient, G EV is the electric vehicle transfer function, δ EV is the primary frequency modulation coefficient of electric vehicles, T EV is the time response coefficient of the electric vehicle;

[0081] The communication model between regions is:

[0082]

[0083] Among them, M area1 is the equivalent inertia coefficient of region 1, M area2 is the equivalent inertia coefficient of region 2, D area1 is the equivalent damping coefficient of region 1, D area2 is the equivalent damping coefficient of region 2, ΔP WT is the change in active power of the fan, ΔP PV is the change in photovoltaic active power, θ 1 is the transmission coefficient of region 1, θ 2 is the transfer coefficient of region 2, θ 3 is the transmission coefficient of region 3, Δf 1 is the frequency deviation of region 1, Δf PS is the frequency deviation in region 2, Δf IES is the frequency deviation of the power flow in the integrated energy system, ΔP R is the active power variation of thermal power units, M IES is the equivalent inertia coefficient of the comprehensive energy system, D IESis the equivalent damping coefficient of the comprehensive energy system, ΔP E is the change in energy storage active power, ΔP CHP is the active power change of the cogeneration device, ΔP RAC is the change in active power of the air conditioning system, ΔP EV is the active power variation of the electric vehicle system.

[0084] Preferably, the verifying the electric energy flow stable operation capability based on the electric energy flow stable operation verification model includes:

[0085] The active power stable operation capability index model of the low-carbon urban integrated energy system AP :

[0086]

[0087] Among them, P Rated For the grid capacity of low-carbon urban integrated energy system, are the upper and lower boundary values ​​of power fluctuation of electric energy flow, respectively, and ΔP is the active power change of any node in the electric energy flow;

[0088] The frequency stability operation capability index model of the low-carbon urban integrated energy system SF :

[0089]

[0090] Among them, f Rated The power frequency of the low-carbon city integrated energy system grid, are the upper and lower boundary values ​​of the frequency fluctuation of the power flow, respectively, and Δf is the frequency change of any node in the power flow.

[0091] Based on another aspect of the present invention, the present invention provides a comprehensive energy system optimization operation and power flow stability verification system, the system comprising:

[0092] Initial unit to determine the energy flow topology of the low-carbon urban integrated energy system;

[0093] A collection unit, used for collecting stable operation guideline data of electric energy flow of the low-carbon urban integrated energy system to determine the energy flow topology;

[0094] An establishment unit is used to establish an optimal operation model of the low-carbon city integrated energy system and determine the objective function of the optimal operation model; the optimal operation model of the low-carbon city integrated energy system includes a carbon trading cost model of the low-carbon city integrated energy system, an optimal operation subject model of the low-carbon city integrated energy system and an optimal operation constraint model of the low-carbon city integrated energy system; based on the optimal operation model, an electric energy flow stable operation verification model of the low-carbon city integrated energy system is established;

[0095] A verification unit is used to verify the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow.

[0096] Preferably, the initial unit is used to determine the energy flow topology of the low-carbon urban integrated energy system, including:

[0097] Based on the energy supply, energy consumption and electricity load data of the low-carbon city comprehensive energy system, the energy flow topology of the low-carbon city comprehensive energy system is determined.

[0098] Preferably, the collection unit is used to collect the electric energy flow stable operation guide data of the low-carbon urban integrated energy system, wherein the electric energy flow stable operation guide data includes:

[0099] The upper and lower boundary values ​​of power fluctuation of electric energy flow are

[0100] The upper and lower boundary values ​​of the power flow frequency fluctuation are

[0101] Preferably, the electric energy flow stable operation verification model includes a low-carbon city integrated energy system carbon trading cost model:

[0102] The total equivalent calorific value of the low-carbon urban integrated energy system is the carbon emission quota allocated to the source unit. The carbon emission quota Q at time t is e,t for:

[0103]

[0104] Among them, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t;

[0105] The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for:

[0106]

[0107] Among them, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively, and satisfy:

[0108] γ GT =γ GB =τ·C arc ·Cc ·δ oc

[0109] Among them, τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δ oc The carbon oxidation rate of coal for carbon-fired projects;

[0110] Carbon trading cost C at time t Ca,t for:

[0111] C Ca,t =α Ca (Q Act,t -Q e,t )

[0112] Among them, α Ca is the carbon trading market price.

[0113] Preferably, the establishing unit is used to establish a stable operation verification model of electric energy flow of the low-carbon city integrated energy system, wherein the stable operation verification model of electric energy flow includes an optimized operation subject model of the low-carbon city integrated energy system:

[0114] The goal of the low-carbon city integrated energy system optimization operation subject model is to minimize the comprehensive operation cost of the low-carbon city integrated energy system, including energy purchase cost, operation and maintenance cost, carbon trading cost and carbon storage cost, as follows:

[0115]

[0116] Among them, f is the comprehensive operating cost of the low-carbon urban integrated energy system, T represents an operating cycle, and C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost;

[0117] The energy acquisition cost of the low-carbon urban integrated energy system is:

[0118]

[0119] in, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,t is the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively;

[0120] The carbon trading cost of the low-carbon city integrated energy system is:

[0121]

[0122] The operation and maintenance cost of the low-carbon urban integrated energy system is:

[0123]

[0124] Among them, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in the low-carbon urban integrated energy system during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in economic optimization in the low-carbon urban integrated energy system;

[0125] The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated:

[0126]

[0127] The cost of carbon sequestration is:

[0128]

[0129] Among them, η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the low-carbon city comprehensive energy system in period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture power plants, E Cs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

[0130] Preferably, the establishing unit is used to establish the electric energy flow stable operation verification model of the low-carbon city integrated energy system, wherein the electric energy flow stable operation verification model includes the low-carbon city integrated energy system optimization operation constraint model:

[0131] The optimization operation constraint model of the low-carbon city comprehensive energy system includes: wind power output constraint, photovoltaic output constraint, energy balance constraint, CHP constraint, equipment energy conversion constraint, electricity consumption willingness constraint, energy storage operation constraint, and electric vehicle charging and discharging constraint;

[0132] The wind power output constraint is that the actual wind power output is often less than the predicted output:

[0133]

[0134] in, They are the actual wind power output and predicted wind power output at time t respectively;

[0135] The photovoltaic output constraint is that the actual photovoltaic output is often less than the predicted output:

[0136]

[0137] in, They are the actual photovoltaic output and predicted output at time t respectively;

[0138] The energy balance constraint is that the low-carbon city comprehensive energy system includes electric energy flow, thermal energy flow and gas energy flow, all of which must meet the energy balance constraint:

[0139]

[0140] in, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption, and GB gas consumption at time t;

[0141] Cogeneration constraints include electricity and heat generation constraints of cogeneration and gas-to-electricity and gas-to-heat constraints of gas boilers:

[0142]

[0143] in, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHBis the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC The power generation efficiency of the waste heat power generation device;

[0144] The equipment energy conversion constraint is that the conversion amount of electrical load and thermal load shall not exceed the upper and lower limits:

[0145]

[0146] in, are the minimum and maximum replacement amounts of the replaceable electric load, x are the minimum and maximum replacement amounts of the replaceable heat load respectively; ΔP t Re , ΔP t Rh They are the replaceable electric load and replaceable thermal load at time t respectively;

[0147] The power consumption willingness constraint is to define the power consumption response willingness coefficient as the difference between the constant 1 and the power consumption substitution coefficient; the power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load:

[0148]

[0149] χ ACL ≥χ ACLmin

[0150] In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin is the minimum value of the electricity consumption response willingness coefficient; is the initial load at time t, is the initial load reduction at time t, is the load that can be adjusted at time t;

[0151] Energy storage operation constraints require that energy storage equipment meet the following constraints:

[0152]

[0153] in, is the remaining capacity of the ith energy storage device at the end of the 24th hour, is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,tThey are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t;

[0154] The charging and discharging constraints of electric vehicles are:

[0155]

[0156] in, They are the charging and discharging start and stop status flags of the i-th electric vehicle in time period t;

[0157] The active power transmission constraint of DC transmission is:

[0158]

[0159] in, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

[0160] Preferably, the step of establishing a stable operation verification model of electric energy flow of the low-carbon urban integrated energy system includes:

[0161] The internal energy supply and consumption unit model of the low-carbon urban comprehensive energy system is:

[0162]

[0163] Among them, G PV is the photovoltaic transfer function, k PV is the photovoltaic time coefficient, U PV is the photovoltaic DC side voltage, C PV is the photovoltaic capacitance, H PV is the photovoltaic equivalent inertia time constant, s is the Laplace operator calculated in the frequency domain, G HVDC is the high voltage DC transfer function, α HVDC is the high voltage DC droop control coefficient, T HVDC is the high voltage DC time response coefficient, G W is the fan transfer function, k df is the fan inertia response coefficient, k pf is the fan primary frequency modulation response coefficient, T ω is the rotor inertia response time constant, T β is the pitch angle response time constant, G sg is the speed regulator transfer function, G st is the turbine transfer function, T g is the speed regulator response time constant, k R is the mechanical power factor, F H is the work coefficient of the high pressure cylinder, TR is the time response coefficient of thermal power, R is the frequency modulation coefficient of thermal power, G E is the energy storage transfer function, k E is the primary frequency modulation coefficient of energy storage, T E is the time response coefficient of energy storage, G CHP is the transfer function of the combined heat and power plant, δ CHP is the primary frequency modulation coefficient of the cogeneration unit, T CHP is the time response coefficient of the cogeneration device, G RAC is the air conditioning transfer function, δ RAC is the primary frequency modulation coefficient of the air conditioner, T RAC is the air conditioning time response coefficient, G EV is the electric vehicle transfer function, δ EV is the primary frequency modulation coefficient of electric vehicles, T EV is the time response coefficient of the electric vehicle;

[0164] The communication model between regions is:

[0165]

[0166] Among them, M area1 is the equivalent inertia coefficient of region 1, M area2 is the equivalent inertia coefficient of region 2, D area1 is the equivalent damping coefficient of region 1, D area2 is the equivalent damping coefficient of region 2, ΔP WT is the change in active power of the fan, ΔP PV is the change in photovoltaic active power, θ 1 is the transmission coefficient of region 1, θ 2 is the transfer coefficient of region 2, θ 3 is the transmission coefficient of region 3, Δf 1 is the frequency deviation of region 1, Δf PS is the frequency deviation in region 2, Δf IES is the frequency deviation of the power flow in the integrated energy system, ΔP R is the active power variation of thermal power units, M IES is the equivalent inertia coefficient of the comprehensive energy system, D IES is the equivalent damping coefficient of the comprehensive energy system, ΔP E is the change in energy storage active power, ΔP CHP is the active power change of the cogeneration device, ΔP RAC is the change in active power of the air conditioning system, ΔP EV is the active power variation of the electric vehicle system.

[0167] Preferably, the verification unit is used to verify the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow, including:

[0168] The active power stable operation capability index model of the low-carbon urban integrated energy system AP :

[0169]

[0170] Among them, P Rated For the grid capacity of low-carbon urban integrated energy system, are the upper and lower boundary values ​​of power fluctuation of electric energy flow, respectively, and ΔP is the active power change of any node in the electric energy flow;

[0171] The frequency stability operation capability index model of the low-carbon urban integrated energy system SF :

[0172]

[0173] Among them, f Rated The power frequency of the low-carbon city integrated energy system grid, are the upper and lower boundary values ​​of the frequency fluctuation of the power flow, respectively, and Δf is the frequency change of any node in the power flow.

[0174] The technical solution of the present invention provides a method and system for optimizing the operation of an integrated energy system and verifying the stability of electric energy flow, wherein the method includes: determining the energy flow topology of a low-carbon city integrated energy system; collecting the electric energy flow stable operation guideline data of the low-carbon city integrated energy system that determines the energy flow topology; establishing an optimized operation model of the low-carbon city integrated energy system, and determining the objective function of the optimized operation model; the optimized operation model of the low-carbon city integrated energy system includes a carbon trading cost model of the low-carbon city integrated energy system, an optimized operation subject model of the low-carbon city integrated energy system, and an optimized operation constraint model of the low-carbon city integrated energy system; based on the optimized operation model, establishing a stable operation verification model of the electric energy flow of the low-carbon city integrated energy system; and verifying the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow. The technical solution of the present invention establishes a carbon trading cost model of the low-carbon city integrated energy system; proposes an optimized operation model of the low-carbon city integrated energy system; proposes a stable operation verification model of the electric energy flow of the low-carbon city integrated energy system; and proposes a final accounting model of the stable operation capability of the electric energy flow of the low-carbon city integrated energy system, which provides a reference for the construction of the optimized operation strategy of low-carbon cities under the current "dual carbon" goal. BRIEF DESCRIPTION OF THE DRAWINGS

[0175] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0176] Figure 1A flow chart of a method for optimizing operation of a comprehensive energy system and verifying the stability of electric energy flow according to a preferred embodiment of the present invention;

[0177] Figure 2 A flow chart of a method for optimizing operation of a comprehensive energy system and verifying the stability of electric energy flow according to a preferred embodiment of the present invention;

[0178] Figure 3 A structural diagram of a low-carbon city integrated energy system electric energy flow stable operation verification model according to a preferred embodiment of the present invention;

[0179] Figure 4 It is a diagram showing the power transmission results of the electric energy flow air conditioning of the integrated energy system according to the preferred embodiment of the present invention;

[0180] Figure 5 Install the external temperature for the integrated energy system electric energy flow air conditioner according to the preferred embodiment of the present invention;

[0181] Figure 6 is the total operating cost of the integrated energy system according to the preferred embodiment of the present invention at different gas turbine operating efficiencies;

[0182] Figure 7 A frequency characteristic curve of a power system according to a preferred embodiment of the present invention;

[0183] Figure 8 A frequency characteristic curve of a comprehensive energy system according to a preferred embodiment of the present invention; and

[0184] Fig. 9 This is a structural diagram of a comprehensive energy system optimization operation and power flow stability verification system according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0185] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0186] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0187] Figure 1The present invention is a flowchart of a method for optimizing operation of an integrated energy system and verifying the stability of electric energy flow according to a preferred embodiment of the present invention.

[0188] The present invention proposes an integrated energy system optimization operation and power flow stability verification model suitable for low-carbon cities, establishes a low-carbon optimization operation model for the integrated energy system in low-carbon cities, and establishes a power flow stability verification model within the integrated energy system in low-carbon cities.

[0189] The present invention provides a comprehensive energy system optimization operation and power flow stability verification model and system suitable for low-carbon cities, which solves the technical problem of lack of low-carbon optimization operation verification method for low-carbon comprehensive energy systems.

[0190] like Figure 1 As shown, the present invention provides a method for optimizing the operation of a comprehensive energy system and verifying the stability of electric energy flow, the method comprising:

[0191] Step 101: Determine the energy flow topology of the low-carbon urban integrated energy system;

[0192] Preferably, determining the energy flow topology of the low-carbon urban integrated energy system includes:

[0193] Based on the energy supply, energy consumption and electricity load data of the low-carbon urban integrated energy system, the energy flow topology of the low-carbon urban integrated energy system is determined.

[0194] The present invention determines the energy flow topology of the low-carbon urban integrated energy system;

[0195] The present invention collects energy supply, energy consumption and electricity load data of a low-carbon city comprehensive energy system, and determines the energy flow topology of the low-carbon city comprehensive energy system.

[0196] Step 102: Collecting stable operation guideline data of electric energy flow of a low-carbon urban integrated energy system that determines the energy flow topology;

[0197] Preferably, the electric energy flow stable operation guideline data of the low-carbon urban integrated energy system is collected, wherein the electric energy flow stable operation guideline data includes:

[0198] The upper and lower boundary values ​​of power fluctuation of electric energy flow are

[0199] The upper and lower boundary values ​​of the power flow frequency fluctuation are

[0200] The present invention collects data on stable operation guidelines for electric energy flow in a low-carbon urban integrated energy system.

[0201] The present invention collects data on stable operation guidelines for electric energy flow in a low-carbon urban integrated energy system.

[0202] Determine the upper and lower boundary values ​​of power fluctuation of electric energy flow respectively:

[0203] Determine the upper and lower boundary values ​​of the power flow frequency fluctuation respectively:

[0204] Step 103: Establish an optimal operation model of a low-carbon city integrated energy system and determine the objective function of the optimal operation model; the optimal operation model of a low-carbon city integrated energy system includes a carbon transaction cost model of a low-carbon city integrated energy system, an optimal operation subject model of a low-carbon city integrated energy system and an optimal operation constraint model of a low-carbon city integrated energy system;

[0205] Preferably, the electric energy flow stable operation verification model includes a low-carbon city integrated energy system carbon trading cost model:

[0206] The total equivalent calorific value of the low-carbon city comprehensive energy system is used to allocate carbon emission quotas to the source units. The carbon emission quota Q at time t is e,t for:

[0207]

[0208] Among them, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t;

[0209] The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for:

[0210]

[0211] Among them, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively, and satisfy:

[0212] γ GT =γ GB =τ·C arc ·C c ·δ oc

[0213] Among them, τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δ oc The carbon oxidation rate of coal for carbon-fired projects;

[0214] Carbon trading cost C at time t Ca,t for:

[0215] C Ca,t =α Ca (Q Act,t -Q e,t )

[0216] Among them, α Ca is the carbon trading market price.

[0217] Preferably, a power flow stable operation verification model of a low-carbon city integrated energy system is established, wherein the power flow stable operation verification model includes an optimized operation subject model of a low-carbon city integrated energy system:

[0218] The goal of the low-carbon city integrated energy system optimization operation subject model is to minimize the comprehensive operation cost of the low-carbon city integrated energy system, including energy purchase cost, operation and maintenance cost, carbon trading cost and carbon storage cost, as follows:

[0219]

[0220] Among them, f is the comprehensive operating cost of the low-carbon urban integrated energy system, T represents an operating cycle, and C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost;

[0221] The energy acquisition cost of the low-carbon urban integrated energy system is:

[0222]

[0223] in, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,t is the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively;

[0224] The carbon trading cost of the low-carbon city integrated energy system is:

[0225]

[0226] The operation and maintenance cost of the low-carbon urban integrated energy system is:

[0227]

[0228] Among them, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in the low-carbon urban integrated energy system during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in economic optimization in the low-carbon urban integrated energy system;

[0229] The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated:

[0230]

[0231] The cost of carbon sequestration is:

[0232]

[0233] Among them, η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the low-carbon city comprehensive energy system in period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture power plants, E Cs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

[0234] Preferably, a power flow stable operation verification model of a low-carbon city integrated energy system is established, wherein the power flow stable operation verification model includes an optimized operation constraint model of a low-carbon city integrated energy system:

[0235] The optimal operation constraint model of the low-carbon city integrated energy system includes: wind power output constraint, photovoltaic output constraint, energy balance constraint, CHP constraint, equipment energy conversion constraint, electricity consumption willingness constraint, energy storage operation constraint, and electric vehicle charging and discharging constraint;

[0236] The wind power output constraint is that the actual wind power output is often less than the predicted output:

[0237]

[0238] in, They are the actual wind power output and predicted wind power output at time t respectively;

[0239] The photovoltaic output constraint is that the actual photovoltaic output is often less than the predicted output:

[0240]

[0241] in, They are the actual photovoltaic output and predicted output at time t respectively;

[0242] The energy balance constraint is that the low-carbon city comprehensive energy system includes electricity flow, heat flow and gas flow, all of which must meet the energy balance constraint:

[0243]

[0244] in, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption, and GB gas consumption at time t;

[0245] Cogeneration constraints include electricity and heat generation constraints of cogeneration and gas-to-electricity and gas-to-heat constraints of gas boilers:

[0246]

[0247] in, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHB is the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC The power generation efficiency of the waste heat power generation device;

[0248] The equipment energy conversion constraint is that the conversion amount of electrical load and thermal load shall not exceed the upper and lower limits:

[0249]

[0250] in, are the minimum and maximum replacement amounts of the replaceable electric load, x are the minimum and maximum replacement amounts of the replaceable heat load respectively; ΔP t Re , ΔP t Rh They are the replaceable electric load and replaceable thermal load at time t respectively;

[0251] The power consumption willingness constraint is to define the power consumption response willingness coefficient as the difference between the constant 1 and the power consumption substitution coefficient; the power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load:

[0252]

[0253] χ ACL ≥χ ACLmin

[0254] In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin is the minimum value of the electricity consumption response willingness coefficient; is the initial load at time t, is the initial load reduction at time t, is the load that can be adjusted at time t;

[0255] Energy storage operation constraints require that energy storage equipment meet the following constraints:

[0256]

[0257] in, is the remaining capacity of the ith energy storage device at the end of the 24th hour, is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,t They are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t;

[0258] The charging and discharging constraints of electric vehicles are:

[0259]

[0260] in, They are the charging and discharging start and stop status flags of the i-th electric vehicle in time period t;

[0261] The active power transmission constraint of DC transmission is:

[0262]

[0263] in, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

[0264] like Figure 2 As shown, the present invention establishes a carbon trading cost model for a low-carbon city integrated energy system;

[0265] The present invention establishes an optimized operation model of a low-carbon city comprehensive energy system, including establishing a carbon transaction cost model of a low-carbon city comprehensive energy system:

[0266] The total equivalent calorific value of the integrated energy system is used to allocate carbon emission quotas to the source units. The carbon emission quota Q at time t is e,t for:

[0267]

[0268] In the formula, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t.

[0269] The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for:

[0270]

[0271] In the formula, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively. And they satisfy:

[0272] γ GT =γ GB =τ·C arc ·C c ·δ oc

[0273] Where τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δoc It is the carbon oxidation rate of coal in carbon-fired projects.

[0274] Carbon trading cost C at time t Ca,t for:

[0275] C Ca,t =α Ca (Q Act,t -Q e,t )

[0276] In the formula, α Ca is the carbon trading market price.

[0277] The present invention establishes an optimized operation model of a low-carbon city comprehensive energy system, and also includes:

[0278] (1) Establish a low-carbon city integrated energy system optimization operation subject model;

[0279] (2) Establish an optimal operation constraint model for the integrated energy system of low-carbon cities.

[0280] The present invention establishes a low-carbon city comprehensive energy system optimization operation subject model:

[0281] The goal is to minimize the comprehensive operating cost of the low-carbon urban integrated energy system, which mainly includes energy purchase costs, operation and maintenance costs, carbon trading costs and carbon storage costs, as follows:

[0282]

[0283] Where, f is the comprehensive operating cost of IES, T represents an operating cycle, C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost.

[0284] The energy acquisition cost of the low-carbon urban integrated energy system is:

[0285]

[0286] In the formula, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,tis the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively.

[0287] The carbon trading cost of the low-carbon city integrated energy system is:

[0288]

[0289] The operation and maintenance cost of the low-carbon urban integrated energy system is:

[0290]

[0291] In the formula, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in IES during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in the economic optimization of IES.

[0292] The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated:

[0293]

[0294] The cost of carbon sequestration is:

[0295]

[0296] Where η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the system during period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture power plants, E Cs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

[0297] The present invention establishes an optimized operation constraint model for a low-carbon urban integrated energy system:

[0298] IES optimized operation constraints include: wind power output constraints, photovoltaic output constraints, energy balance constraints, CHP constraints, equipment energy conversion constraints, electricity consumption willingness constraints, energy storage operation constraints, and electric vehicle charging and discharging constraints.

[0299] (1) Wind power output constraints

[0300] The actual output of wind power is often less than the predicted output:

[0301]

[0302] In the formula, are the actual wind power output and predicted wind power output at time t respectively.

[0303] (2) Photovoltaic output constraints

[0304] Similar to wind power output characteristics, the actual output of photovoltaic power is often less than the predicted output:

[0305]

[0306] In the formula, They are the actual photovoltaic output and predicted output at time t respectively.

[0307] (3) Energy balance constraints

[0308] The urban integrated energy system includes electrical energy flow, thermal energy flow and gas energy flow, all of which need to meet energy balance constraints. Therefore, the following conditions must be met:

[0309]

[0310] In the formula, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption and GB gas consumption at time t respectively.

[0311] (4) Cogeneration constraints

[0312] Cogeneration constraints include the electricity and heat generation constraints of cogeneration and the gas-to-electricity and gas-to-heat constraints of gas boilers, as follows:

[0313]

[0314] In the formula, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHBis the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC is the power generation efficiency of the waste heat power generation device.

[0315] (5) Equipment energy conversion constraints

[0316] The conversion amount of electrical load and thermal load shall not exceed the upper and lower limits:

[0317]

[0318] In the formula, are the minimum and maximum replacement amounts of the replaceable electric load, are the minimum and maximum replacement amounts of replaceable heat load respectively.

[0319] (6) Constraints on electricity consumption

[0320] The power consumption response willingness coefficient is defined as the difference between the constant 1 and the power consumption substitution coefficient. The power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load, that is,

[0321]

[0322] χ ACL ≥χ ACLmin

[0323] In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin It is the minimum value of the electricity consumption response willingness coefficient.

[0324] (7) Energy storage operation constraints

[0325] In order to ensure the sustainable dispatch of energy storage equipment, the remaining capacity of the energy storage equipment is equal at the beginning and end of the dispatch cycle; at the same time, in order to prevent the impact of excessive charging and discharging frequency on the battery life, the energy storage equipment needs to meet the following constraints:

[0326]

[0327] In the formula, is the remaining capacity of the ith energy storage device at the end of the 24th hour, is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,tThey are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t.

[0328] (8) Electric vehicle charging and discharging constraints

[0329]

[0330] In the formula, They are respectively the charging and discharging start and stop status flags of the i-th electric vehicle in time period t.

[0331] (9) DC power transmission constraints

[0332]

[0333] In the formula, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

[0334] Step 104: Based on the optimized operation model, a power flow stable operation verification model of the low-carbon urban integrated energy system is established;

[0335] Preferably, a stable operation verification model of electric energy flow of a low-carbon urban integrated energy system is established, including:

[0336] The internal energy supply and consumption unit model of the low-carbon city comprehensive energy system is:

[0337]

[0338] Among them, G PV is the photovoltaic transfer function, k PV is the photovoltaic time coefficient, U PV is the photovoltaic DC side voltage, C PV is the photovoltaic capacitance, H PV is the photovoltaic equivalent inertia time constant, s is the Laplace operator calculated in the frequency domain, G HVDC is the high voltage DC transfer function, α HVDC is the high voltage DC droop control coefficient, T HVDC is the high voltage DC time response coefficient, G W is the fan transfer function, k df is the fan inertia response coefficient, k pf is the fan primary frequency modulation response coefficient, T ω is the rotor inertia response time constant, T β is the pitch angle response time constant, G sg is the speed regulator transfer function, G st is the turbine transfer function, Tg is the speed regulator response time constant, k R is the mechanical power factor, F H is the work coefficient of the high pressure cylinder, T R is the time response coefficient of thermal power, R is the frequency modulation coefficient of thermal power, G E is the energy storage transfer function, k E is the primary frequency modulation coefficient of energy storage, T E is the time response coefficient of energy storage, G CHP is the transfer function of the combined heat and power plant, δ CHP is the primary frequency modulation coefficient of the cogeneration unit, T CHP is the time response coefficient of the cogeneration device, G RAC is the air conditioning transfer function, δ RAC is the primary frequency modulation coefficient of the air conditioner, T RAC is the air conditioning time response coefficient, G EV is the electric vehicle transfer function, δ EV is the primary frequency modulation coefficient of electric vehicles, T EV is the time response coefficient of the electric vehicle;

[0339] The communication model between regions is:

[0340]

[0341] Among them, M area1 is the equivalent inertia coefficient of region 1, M area2 is the equivalent inertia coefficient of region 2, D area1 is the equivalent damping coefficient of region 1, D area2 is the equivalent damping coefficient of region 2, ΔP WT is the change in active power of the fan, ΔP PV is the change in photovoltaic active power, θ 1 is the transmission coefficient of region 1, θ 2 is the transfer coefficient of region 2, θ 3 is the transmission coefficient of region 3, Δf 1 is the frequency deviation of region 1, Δf PS is the frequency deviation in region 2, Δf IES is the frequency deviation of the power flow in the integrated energy system, ΔP R is the active power variation of thermal power units, M IES is the equivalent inertia coefficient of the comprehensive energy system, D IES is the equivalent damping coefficient of the comprehensive energy system, ΔP E is the change in energy storage active power, ΔP CHP is the active power change of the cogeneration device, ΔP RAC is the change in active power of the air conditioning system, ΔP EV is the active power variation of the electric vehicle system.

[0342] The present invention establishes a verification model for the stable operation of electric energy flow in a low-carbon urban integrated energy system;

[0343] The present invention establishes a verification model for the stable operation of electric energy flow in a low-carbon urban integrated energy system.

[0344] The internal energy supply and consumption unit model of the urban integrated energy system is:

[0345]

[0346] The communication model between regions is:

[0347]

[0348] All parameters in the formula are explained as follows:

[0349]

[0350] Step 105: Verify the stable operation capability of the power flow based on the stable operation verification model of the power flow.

[0351] Preferably, the electric energy flow stable operation capability is verified based on the electric energy flow stable operation verification model, including:

[0352] Active power stable operation capability index model of low-carbon urban integrated energy system AP :

[0353]

[0354] Among them, P Rated For the grid capacity of low-carbon urban integrated energy system, are the upper and lower boundary values ​​of power fluctuation of electric energy flow, respectively, and ΔP is the active power change of any node in the electric energy flow;

[0355] Frequency stability operation capability index model of low-carbon urban integrated energy system SF :

[0356]

[0357] Among them, f Rated For low-carbon city integrated energy system power grid frequency, are the upper and lower boundary values ​​of the frequency fluctuation of the power flow, respectively, and Δf is the frequency change of any node in the power flow.

[0358] The present invention performs a final accounting of the stable operation capacity of the electric energy flow of a low-carbon urban integrated energy system.

[0359] System active power stable operation capability index model AP :

[0360]

[0361] Where P Rated Grid capacity for low-carbon urban integrated energy systems.

[0362] System frequency stable operation capability index model SF :

[0363]

[0364] In the formula, f Rated is the power frequency of the low-carbon city integrated energy system grid. 1 , Δf PS , Δf IES Both can be used as the system frequency stable operation capability indicator model SF Δf in the. Figure 3 shown.

[0365] The present invention establishes a carbon trading cost model for a low-carbon city's integrated energy system; proposes an optimized operation model for a low-carbon city's integrated energy system; proposes a verification model for the stable operation of electric energy flow in a low-carbon city's integrated energy system; and proposes a final accounting model for the stable operation capacity of electric energy flow in a low-carbon city's integrated energy system, providing a reference for the construction of an optimized operation strategy for low-carbon cities under the current "dual carbon" goal.

[0366] Figure 4 This is a structural diagram of a comprehensive energy system optimization operation and power flow stability verification system according to a preferred embodiment of the present invention.

[0367] like Figure 4 As shown, the present invention provides a comprehensive energy system optimization operation and power flow stability verification system, the system comprising:

[0368] Initial unit 401, for determining the energy flow topology of the low-carbon urban integrated energy system;

[0369] Preferably, the initial unit 401, used to determine the energy flow topology of the low-carbon urban integrated energy system, includes:

[0370] Based on the energy supply, energy consumption and electricity load data of the low-carbon urban integrated energy system, the energy flow topology of the low-carbon urban integrated energy system is determined.

[0371] The collection unit 402 is used to collect the electric energy flow stable operation guideline data of the low-carbon urban integrated energy system that determines the energy flow topology;

[0372] Preferably, the collection unit 402 is used to collect the electric energy flow stable operation guide data of the low-carbon urban integrated energy system, wherein the electric energy flow stable operation guide data includes:

[0373] The upper and lower boundary values ​​of power fluctuation of electric energy flow are

[0374] The upper and lower boundary values ​​of the power flow frequency fluctuation are

[0375] Establishing unit 403, used to establish an optimized operation model of a low-carbon city integrated energy system and determine the objective function of the optimized operation model; the optimized operation model of the low-carbon city integrated energy system includes a carbon trading cost model of the low-carbon city integrated energy system, an optimized operation subject model of the low-carbon city integrated energy system and an optimized operation constraint model of the low-carbon city integrated energy system; based on the optimized operation model, establish a stable operation verification model of electric energy flow of the low-carbon city integrated energy system;

[0376] Preferably, the electric energy flow stable operation verification model includes a low-carbon city integrated energy system carbon trading cost model:

[0377] The total equivalent calorific value of the low-carbon city comprehensive energy system is used to allocate carbon emission quotas to the source units. The carbon emission quota Q at time t is e,t for:

[0378]

[0379] Among them, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t;

[0380] The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for:

[0381]

[0382] Among them, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively, and satisfy:

[0383] γ GT =γ GB =τ·C arc ·C c ·δ oc

[0384] Among them, τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δ oc The carbon oxidation rate of coal for carbon-fired projects;

[0385] Carbon trading cost C at time t Ca,t for:

[0386] C Ca,t =α Ca (Q Act,t -Q e,t )

[0387] Among them, α Ca is the carbon trading market price.

[0388] Preferably, the establishing unit is used to establish a power flow stable operation verification model of the low-carbon city integrated energy system, wherein the power flow stable operation verification model includes an optimized operation subject model of the low-carbon city integrated energy system:

[0389] The goal of the low-carbon city integrated energy system optimization operation subject model is to minimize the comprehensive operation cost of the low-carbon city integrated energy system, including energy purchase cost, operation and maintenance cost, carbon trading cost and carbon storage cost, as follows:

[0390]

[0391] Among them, f is the comprehensive operating cost of the low-carbon urban integrated energy system, T represents an operating cycle, and C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost;

[0392] The energy acquisition cost of the low-carbon urban integrated energy system is:

[0393]

[0394] in, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,tis the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively;

[0395] The carbon trading cost of the low-carbon city integrated energy system is:

[0396]

[0397] The operation and maintenance cost of the low-carbon urban integrated energy system is:

[0398]

[0399] Among them, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in the low-carbon urban integrated energy system during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in economic optimization in the low-carbon urban integrated energy system;

[0400] The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated:

[0401]

[0402] The cost of carbon sequestration is:

[0403]

[0404] Among them, η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the low-carbon city comprehensive energy system in period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture plants, E Cs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

[0405] Preferably, the establishing unit is used to establish a power flow stable operation verification model of the low-carbon city integrated energy system, wherein the power flow stable operation verification model includes an optimized operation constraint model of the low-carbon city integrated energy system:

[0406] The optimal operation constraint model of the low-carbon city integrated energy system includes: wind power output constraint, photovoltaic output constraint, energy balance constraint, CHP constraint, equipment energy conversion constraint, electricity consumption willingness constraint, energy storage operation constraint, and electric vehicle charging and discharging constraint;

[0407] The wind power output constraint is that the actual wind power output is often less than the predicted output:

[0408]

[0409] in, They are the actual wind power output and predicted wind power output at time t respectively;

[0410] The photovoltaic output constraint is that the actual photovoltaic output is often less than the predicted output:

[0411]

[0412] in, They are the actual photovoltaic output and predicted output at time t respectively;

[0413] The energy balance constraint is that the low-carbon city comprehensive energy system includes electricity flow, heat flow and gas flow, all of which must meet the energy balance constraint:

[0414]

[0415] in, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption, and GB gas consumption at time t;

[0416] Cogeneration constraints include electricity and heat generation constraints of cogeneration and gas-to-electricity and gas-to-heat constraints of gas boilers:

[0417]

[0418] in, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHBis the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC The power generation efficiency of the waste heat power generation device;

[0419] The equipment energy conversion constraint is that the conversion amount of electrical load and thermal load shall not exceed the upper and lower limits:

[0420]

[0421] in, are the minimum and maximum replacement amounts of the replaceable electric load, are the minimum and maximum replacement amounts of the replaceable heat load respectively; ΔP t Re , ΔP t Rh They are the replaceable electric load and replaceable thermal load at time t respectively;

[0422] The power consumption willingness constraint is to define the power consumption response willingness coefficient as the difference between the constant 1 and the power consumption substitution coefficient; the power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load:

[0423]

[0424] χ ACL ≥χ ACLmin

[0425] In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin is the minimum value of the electricity consumption response willingness coefficient; is the initial load at time t, is the initial load reduction at time t, is the adjustable load at time t; the energy storage operation constraint is that the energy storage equipment needs to meet the following constraints:

[0426]

[0427] in, is the remaining capacity of the ith energy storage device at the end of the 24th hour, is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,t They are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t;

[0428] The charging and discharging constraints of electric vehicles are:

[0429]

[0430] in, They are the charging and discharging start and stop status flags of the i-th electric vehicle in time period t;

[0431] The active power transmission constraint of DC transmission is:

[0432]

[0433] in, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

[0434] Preferably, a stable operation verification model of electric energy flow of a low-carbon urban integrated energy system is established, including:

[0435] The internal energy supply and consumption unit model of the low-carbon city comprehensive energy system is:

[0436]

[0437] Among them, G PV is the photovoltaic transfer function, k PV is the photovoltaic time coefficient, U PV is the photovoltaic DC side voltage, C PV is the photovoltaic capacitance, H PV is the photovoltaic equivalent inertia time constant, s is the Laplace operator calculated in the frequency domain, G HVDC is the high voltage DC transfer function, α HVDC is the high voltage DC droop control coefficient, T HVDC is the high voltage DC time response coefficient, G W is the fan transfer function, k df is the fan inertia response coefficient, k pf is the fan primary frequency modulation response coefficient, T ω is the rotor inertia response time constant, T β is the pitch angle response time constant, G sg is the speed regulator transfer function, G st is the turbine transfer function, T g is the speed regulator response time constant, k R is the mechanical power factor, F H is the work coefficient of the high pressure cylinder, T R is the time response coefficient of thermal power, R is the frequency modulation coefficient of thermal power, GE is the energy storage transfer function, k E is the primary frequency modulation coefficient of energy storage, T E is the time response coefficient of energy storage, G CHP is the transfer function of the combined heat and power plant, δ CHP is the primary frequency modulation coefficient of the cogeneration unit, T CHP is the time response coefficient of the cogeneration device, G RAC is the air conditioning transfer function, δ RAC is the primary frequency modulation coefficient of the air conditioner, T RAC is the air conditioning time response coefficient, G EV is the electric vehicle transfer function, δ EV is the primary frequency modulation coefficient of electric vehicles, T EV is the time response coefficient of the electric vehicle;

[0438] The communication model between regions is:

[0439]

[0440] Among them, M area1 is the equivalent inertia coefficient of region 1, M area2 is the equivalent inertia coefficient of region 2, D area1 is the equivalent damping coefficient of region 1, D area2 is the equivalent damping coefficient of region 2, ΔP WT is the change in active power of the fan, ΔP PV is the change in photovoltaic active power, θ 1 is the transmission coefficient of region 1, θ 2 is the transfer coefficient of region 2, θ 3 is the transmission coefficient of region 3, Δf 1 is the frequency deviation of region 1, Δf PS is the frequency deviation in region 2, Δf IES is the frequency deviation of the power flow in the integrated energy system, ΔP R is the active power variation of thermal power units, M IES is the equivalent inertia coefficient of the comprehensive energy system, D IES is the equivalent damping coefficient of the comprehensive energy system, ΔP E is the change in energy storage active power, ΔP CHP is the active power change of the cogeneration device, ΔP RAC is the change in active power of the air conditioning system, ΔP EV is the active power variation of the electric vehicle system.

[0441] The verification unit 404 is used to verify the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow.

[0442] Preferably, the verification unit 404 is used to verify the stable operation capability of the power flow based on the stable operation verification model of the power flow, including:

[0443] Active power stable operation capability index model of low-carbon urban integrated energy system AP :

[0444]

[0445] Among them, P Rated For the grid capacity of low-carbon urban integrated energy system, are the upper and lower boundary values ​​of power fluctuation of electric energy flow, respectively, and ΔP is the active power change of any node in the electric energy flow;

[0446] Frequency stability operation capability index model of low-carbon urban integrated energy system SF :

[0447]

[0448] Among them, f Rated For low-carbon city integrated energy system power grid frequency, are the upper and lower boundary values ​​of the frequency fluctuation of the power flow, respectively, and Δf is the frequency change of any node in the power flow.

[0449] A system for optimizing operation of an integrated energy system and verifying stability of electric energy flow according to a preferred embodiment of the present invention corresponds to a method for optimizing operation of an integrated energy system and verifying stability of electric energy flow according to another preferred embodiment of the present invention, and will not be described in detail here.

[0450] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0451] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0452] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0453] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0454] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0455] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0456] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0457] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / / the [means, component, etc.]" are to be openly interpreted as at least one instance of a means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A method for optimizing the operation of an integrated energy system and verifying the stability of electric energy flow, the method comprising: Determine the energy flow topology of low-carbon urban integrated energy systems; Collecting data on stable operation of electric energy flow of the low-carbon urban integrated energy system to determine the energy flow topology; Establishing an optimal operation model of the low-carbon city integrated energy system and determining the objective function of the optimal operation model; the optimal operation model of the low-carbon city integrated energy system includes a carbon transaction cost model of the low-carbon city integrated energy system, an optimal operation subject model of the low-carbon city integrated energy system and an optimal operation constraint model of the low-carbon city integrated energy system; Based on the optimized operation model, a stable operation verification model of electric energy flow of the low-carbon urban integrated energy system is established; The electric energy flow stable operation capability is verified based on the electric energy flow stable operation verification model.

2. According to the method of claim 1, the step of determining the energy flow topology of the low-carbon urban integrated energy system comprises: Based on the energy supply, energy consumption and electricity load data of the low-carbon city comprehensive energy system, the energy flow topology of the low-carbon city comprehensive energy system is determined.

3. The method according to claim 1, wherein the collecting of the electric energy flow stable operation guideline data of the low-carbon urban integrated energy system, wherein the electric energy flow stable operation guideline data comprises: The upper and lower boundary values ​​of power fluctuation of electric energy flow are The upper and lower boundary values ​​of the power flow frequency fluctuation are 4. According to the method of claim 1, the electric energy flow stable operation verification model includes a carbon trading cost model of a low-carbon city integrated energy system: The total equivalent calorific value of the low-carbon urban integrated energy system is the carbon emission quota allocated to the source unit. The carbon emission quota Q at time t is e,t for: in, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t; The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for: Among them, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively, and satisfy: c GT =c GB =τ·C arc ·C c ·d oc Among them, τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δ oc The carbon oxidation rate of coal for carbon-fired projects; Carbon trading cost C at time t Ca,t for: C Ca,t =α Ca (Q Act,t -Q e,t ) Among them, α Ca is the carbon trading market price.

5. According to the method of claim 4, the electric energy flow stable operation verification model of the low-carbon city integrated energy system is established, wherein the electric energy flow stable operation verification model includes a low-carbon city integrated energy system optimization operation subject model: The goal of the low-carbon city integrated energy system optimization operation subject model is to minimize the comprehensive operation cost of the low-carbon city integrated energy system, including energy purchase cost, operation and maintenance cost, carbon trading cost and carbon storage cost, as follows: in, f is the comprehensive operating cost of the low-carbon urban integrated energy system, T represents an operating cycle, C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost; The energy acquisition cost of the low-carbon urban integrated energy system is: in, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,t is the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively; The carbon trading cost of the low-carbon city integrated energy system is: The operation and maintenance cost of the low-carbon urban integrated energy system is: Among them, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in the low-carbon urban integrated energy system during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in economic optimization in the low-carbon urban integrated energy system; The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated: The cost of carbon sequestration is: Among them, η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the low-carbon city comprehensive energy system in period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture power plants, E Cs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

6. The method according to claim 5, wherein the electric energy flow stable operation verification model of the low-carbon city integrated energy system is established, wherein the electric energy flow stable operation verification model includes an optimized operation constraint model of the low-carbon city integrated energy system: The optimization operation constraint model of the low-carbon city comprehensive energy system includes: wind power output constraint, photovoltaic output constraint, energy balance constraint, CHP constraint, equipment energy conversion constraint, electricity consumption willingness constraint, energy storage operation constraint, and electric vehicle charging and discharging constraint; The wind power output constraint is that the actual wind power output is often less than the predicted output: in, They are the actual wind power output and predicted wind power output at time t respectively; The photovoltaic output constraint is that the actual photovoltaic output is often less than the predicted output: in, They are the actual photovoltaic output and predicted output at time t respectively; The energy balance constraint is that the low-carbon city comprehensive energy system includes electric energy flow, thermal energy flow and gas energy flow, all of which must meet the energy balance constraint: in, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption, and GB gas consumption at time t; Cogeneration constraints include electricity and heat generation constraints of cogeneration and gas-to-electricity and gas-to-heat constraints of gas boilers: in, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHB is the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC The power generation efficiency of the waste heat power generation device; The equipment energy conversion constraint is that the conversion amount of electrical load and thermal load shall not exceed the upper and lower limits: in, are the minimum and maximum replacement amounts of the replaceable electric load, x are the minimum and maximum replacement amounts of replaceable heat load respectively; They are the replaceable electric load and replaceable thermal load at time t respectively; The power consumption willingness constraint is to define the power consumption response willingness coefficient as the difference between the constant 1 and the power consumption substitution coefficient; the power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load: x ACL ≥x ACLmin In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin is the minimum value of the electricity consumption response willingness coefficient; is the initial load at time t, is the initial load reduction at time t, is the load that can be adjusted at time t; Energy storage operation constraints require that energy storage equipment meet the following constraints: in, is the remaining capacity of the ith energy storage device at the end of the 24th hour, P i 0 is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,t They are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t; The charging and discharging constraints of electric vehicles are: in, They are the charging and discharging start and stop status flags of the i-th electric vehicle in time period t; The active power transmission constraint of DC transmission is: in, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

7. According to the method of claim 1, the step of establishing a stable operation verification model of electric energy flow of the low-carbon urban integrated energy system comprises: The internal energy supply and consumption unit model of the low-carbon urban comprehensive energy system is: Among them, G PV is the photovoltaic transfer function, k PV is the photovoltaic time coefficient, U PV is the photovoltaic DC side voltage, C PV is the photovoltaic capacitance, H PV is the photovoltaic equivalent inertia time constant, s is the Laplace operator calculated in the frequency domain, G HVDC is the high voltage DC transfer function, α HVDC is the high voltage DC droop control coefficient, T HVDC is the high voltage DC time response coefficient, G W is the fan transfer function, k df is the fan inertia response coefficient, k pf is the fan primary frequency modulation response coefficient, T ω is the rotor inertia response time constant, T β is the pitch angle response time constant, G sg is the speed regulator transfer function, G st is the turbine transfer function, T g k is the speed regulator response time constant, R is the mechanical power factor, F H is the work coefficient of the high pressure cylinder, T R is the time response coefficient of thermal power, R is the frequency modulation coefficient of thermal power, G E is the energy storage transfer function, k E is the primary frequency modulation coefficient of energy storage, T E is the time response coefficient of energy storage, G CHP is the transfer function of the combined heat and power plant, δ CHP is the primary frequency modulation coefficient of the cogeneration unit, T CHP is the time response coefficient of the cogeneration device, G RAC is the air conditioning transfer function, δ RAC is the primary frequency modulation coefficient of the air conditioner, T RAC is the air conditioning time response coefficient, G EV is the electric vehicle transfer function, δ EV is the primary frequency modulation coefficient of electric vehicles, T EV is the electric vehicle time response coefficient; The communication model between regions is: Among them, M area1 is the equivalent inertia coefficient of region 1, M area2 is the equivalent inertia coefficient of region 2, D area1 is the equivalent damping coefficient of region 1, D area2 is the equivalent damping coefficient of region 2, ΔP WT is the change in active power of the fan, ΔP PV is the change in photovoltaic active power, θ1 is the transfer coefficient of area 1, θ2 is the transfer coefficient of area 2, θ3 is the transfer coefficient of area 3, Δf1 is the frequency deviation of area 1, Δf PS is the frequency deviation in region 2, Δf IES is the frequency deviation of the power flow in the integrated energy system, ΔP R is the active power variation of thermal power units, M IES is the equivalent inertia coefficient of the comprehensive energy system, D IES is the equivalent damping coefficient of the comprehensive energy system, ΔP E is the change in active energy storage, ΔP CHP is the active power change of the cogeneration device, ΔP RAC is the active power change of the air conditioning system, ΔP EV is the active power variation of the electric vehicle system.

8. The method according to claim 1, wherein the step of verifying the stable operation capability of the electric energy flow based on the electric energy flow stable operation verification model comprises: The active power stable operation capability index model of the low-carbon urban integrated energy system AP : Among them, P Rated For the grid capacity of low-carbon urban integrated energy system, are the upper and lower boundary values ​​of power fluctuation of electric energy flow, respectively, and ΔP is the active power change of any node in the electric energy flow; The frequency stability operation capability index model of the low-carbon city comprehensive energy system SF : Among them, f Rated The power frequency of the low-carbon city integrated energy system grid, are the upper and lower boundary values ​​of the frequency fluctuation of the power flow, respectively, and Δf is the frequency change of any node in the power flow.

9. A system for optimizing operation of a comprehensive energy system and verifying the stability of electric energy flow, the system comprising: Initial unit to determine the energy flow topology of the low-carbon urban integrated energy system; A collection unit, used for collecting stable operation guideline data of electric energy flow of the low-carbon urban integrated energy system to determine the energy flow topology; An establishment unit is used to establish an optimal operation model of the low-carbon city integrated energy system and determine the objective function of the optimal operation model; the optimal operation model of the low-carbon city integrated energy system includes a carbon trading cost model of the low-carbon city integrated energy system, an optimal operation subject model of the low-carbon city integrated energy system and an optimal operation constraint model of the low-carbon city integrated energy system; based on the optimal operation model, an electric energy flow stable operation verification model of the low-carbon city integrated energy system is established; A verification unit is used to verify the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow.

10. The system according to claim 9, wherein the initial unit is used to determine the energy flow topology of the low-carbon urban integrated energy system, comprising: Based on the energy supply, energy consumption and electricity load data of the low-carbon city comprehensive energy system, the energy flow topology of the low-carbon city comprehensive energy system is determined.

11. The system according to claim 9, wherein the collection unit is used to collect the electric energy flow stable operation guideline data of the low-carbon urban integrated energy system, wherein the electric energy flow stable operation guideline data includes: The upper and lower boundary values ​​of power fluctuation of electric energy flow are The upper and lower boundary values ​​of the power flow frequency fluctuation are 12. The system according to claim 9, wherein the electric energy flow stable operation verification model comprises a carbon trading cost model of a low-carbon city integrated energy system: The total equivalent calorific value of the low-carbon urban integrated energy system is the carbon emission quota allocated to the source unit. The carbon emission quota Q at time t is e,t for: in, γ is the regional unit electricity carbon emission allocation, are the electrical and thermal power output of the gas turbine at time t, η Δ is the power equivalent coefficient, is the thermal power output of the gas boiler at time t; The actual carbon emissions of the system at time t is Q Act,t is the sum of the gas boiler and gas turbine, then the actual carbon emissions of the system at time t is Q Act,t for: Among them, γ GT , γ GB are the carbon emission coefficients of GT and GB respectively, and satisfy: c GT =c GB =τ·C arc ·C c ·d oc Among them, τ is the relative molecular mass of carbon dioxide and carbon, C arc The low base calorific value of the carbon used in the carbon-fired project, C c is the carbon content per unit calorific value of the carbon-burning project, δ oc The carbon oxidation rate of coal for carbon-fired projects; Carbon trading cost C at time t Ca,t for: C Ca,t =α Ca (Q Act,t -Q e,t ) Among them, α Ca is the carbon trading market price.

13. The system according to claim 12, wherein the establishing unit is used to establish a stable operation verification model of electric energy flow of the low-carbon city integrated energy system, wherein the stable operation verification model of electric energy flow comprises an optimized operation subject model of the low-carbon city integrated energy system: The goal of the low-carbon city integrated energy system optimization operation subject model is to minimize the comprehensive operation cost of the low-carbon city integrated energy system, including energy purchase cost, operation and maintenance cost, carbon trading cost and carbon storage cost, as follows: in, f is the comprehensive operating cost of the low-carbon urban integrated energy system, T represents an operating cycle, C BuyEne,t is the energy purchase cost in period t, C Ca,t is the carbon trading cost in period t, C Oper,t is the operation and maintenance cost in period t, C Cs,t is the carbon storage cost in period t, C BuyEne , C Ca , C Oper , C Cs They are total energy purchase cost, carbon trading cost, operation and maintenance cost, and carbon sequestration cost; The energy acquisition cost of the low-carbon urban integrated energy system is: in, They represent the electricity prices for interactive purchase and sale of electricity from the upper power grid at time t, They represent the active power purchased and sold by the ith power consumption unit at time t, V buy,τ,t is the volume of natural gas purchased by the τth gas unit at time t, λ G,t is the unit natural gas price at time t, n G 、n e are the number of gas units and electricity units respectively; The carbon trading cost of the low-carbon city integrated energy system is: The operation and maintenance cost of the low-carbon urban integrated energy system is: Among them, C Oper,i,t is the operation and maintenance cost of the i-th equipment unit in the low-carbon urban integrated energy system during period t, κ i is the operation and maintenance coefficient of the i-th equipment unit, P i,t is the output of the i-th equipment unit, and N is the number of equipment units participating in economic optimization in the low-carbon urban integrated energy system; The carbon sequestration cost of the low-carbon urban integrated energy system is related to the amount of methane generated: The cost of carbon sequestration is: Among them, η P2G,t is the operating efficiency of P2G in period t, P P2G,t is the power consumed by P2G during period t, H g is the calorific value of natural gas, is the methane generation of the system during period t, Q C_CO2,t is the carbon dioxide utilization of the low-carbon city comprehensive energy system in period t, ρ CO2 is the density of carbon dioxide, m Cs is the number of carbon capture power plants, E Cs,i,t is the total amount of carbon dioxide captured by the i-th carbon capture power plant during period t.

14. The system according to claim 13, wherein the establishing unit is used to establish the electric energy flow stable operation verification model of the low-carbon city integrated energy system, wherein the electric energy flow stable operation verification model includes the low-carbon city integrated energy system optimization operation constraint model: The optimization operation constraint model of the low-carbon city comprehensive energy system includes: wind power output constraint, photovoltaic output constraint, energy balance constraint, CHP constraint, equipment energy conversion constraint, electricity consumption willingness constraint, energy storage operation constraint, and electric vehicle charging and discharging constraint; The wind power output constraint is that the actual wind power output is often less than the predicted output: in, They are the actual wind power output and predicted wind power output at time t respectively; The photovoltaic output constraint is that the actual photovoltaic output is often less than the predicted output: in, They are the actual photovoltaic output and predicted output at time t respectively; The energy balance constraint is that the low-carbon city comprehensive energy system includes electric energy flow, thermal energy flow and gas energy flow, all of which must meet the energy balance constraint: in, They represent the active power purchased and sold by the integrated energy system and the upper power grid at time t, are the power consumed and heat generated by HP at time t, are the CHP power generation, heat generation and natural gas consumption at time t, are the battery discharge and charge powers at time t, are the heat release and storage power of the heat storage tank at time t, are the electrical load and thermal load at time t before DR, V buy,t , They are the total gas consumption of gas energy flow, CHP gas consumption, and GB gas consumption at time t; Cogeneration constraints include electricity and heat generation constraints of cogeneration and gas-to-electricity and gas-to-heat constraints of gas boilers: in, is the power generated by the low-temperature waste heat device, ρ t is the ratio of the waste heat generated by GT at time t allocated to WHB for heat generation, η WHB is the heat conversion efficiency of WHB, are the gas-to-electricity and gas-to-heat efficiencies of GT, H g is the calorific value of natural gas, is the proportion of waste heat generated by GT at time t allocated to the waste heat power generation device, η ORC The power generation efficiency of the waste heat power generation device; The equipment energy conversion constraint is that the conversion amount of electrical load and thermal load shall not exceed the upper and lower limits: in, are the minimum and maximum replacement amounts of the replaceable electric load, x are the minimum and maximum replacement amounts of the replaceable heat load respectively; ΔP t Re , ΔP t Rh They are the replaceable electric load and replaceable thermal load at time t respectively; The power consumption willingness constraint is to define the power consumption response willingness coefficient as the difference between the constant 1 and the power consumption substitution coefficient; the power consumption substitution coefficient is defined as the ratio of the absolute value of the sum of the initial load, the load change that can be reduced, the load change that can be adjusted, and the replaceable load at time t in the power consumption cycle to the initial load: x ACL ≥x ACLmin In the formula, χ ACL , χ Deac are the electricity consumption response willingness coefficient and electricity substitution coefficient, respectively, ACLmin is the minimum value of the electricity consumption response willingness coefficient; is the initial load at time t, is the initial load reduction at time t, is the load that can be adjusted at time t; Energy storage operation constraints require that energy storage equipment meet the following constraints: in, is the remaining capacity of the ith energy storage device at the end of the 24th hour, is the initial capacity of the i-th energy storage device, Z E,in,t , Z E,out,t They are the charge and discharge status flags of the energy storage battery. They are respectively the charging and discharging start and stop status flags of the i-th energy storage device in time period t; The charging and discharging constraints of electric vehicles are: in, They are the charging and discharging start and stop status flags of the i-th electric vehicle in time period t; The active power transmission constraint of DC transmission is: in, are the lower and upper limits of active power transmission of the DC transmission system, ΔP HVDC,t is the active power flowing through the HVDC at time t.

15. The system according to claim 9, wherein the step of establishing a stable operation verification model of electric energy flow of the low-carbon urban integrated energy system comprises: The internal energy supply and consumption unit model of the low-carbon urban comprehensive energy system is: Among them, G PV is the photovoltaic transfer function, k PV is the photovoltaic time coefficient, U PV is the photovoltaic DC side voltage, C PV is the photovoltaic capacitance, H PV is the photovoltaic equivalent inertia time constant, s is the Laplace operator calculated in the frequency domain, G HVDC is the high voltage DC transfer function, α HVDC is the high voltage DC droop control coefficient, T HVDC is the high voltage DC time response coefficient, G W is the fan transfer function, k df is the fan inertia response coefficient, k pf is the fan primary frequency modulation response coefficient, T ω is the rotor inertia response time constant, T β is the pitch angle response time constant, G sg is the speed regulator transfer function, G st is the turbine transfer function, T g k is the speed regulator response time constant, R is the mechanical power factor, F H is the work coefficient of the high pressure cylinder, T R is the time response coefficient of thermal power, R is the frequency modulation coefficient of thermal power, G E is the energy storage transfer function, k E is the primary frequency modulation coefficient of energy storage, T E is the time response coefficient of energy storage, G CHP is the transfer function of the combined heat and power plant, δ CHP is the primary frequency modulation coefficient of the cogeneration unit, T CHP is the time response coefficient of the cogeneration device, G RAC is the air conditioning transfer function, δ RAC is the primary frequency modulation coefficient of the air conditioner, T RAC is the air conditioning time response coefficient, G EV is the electric vehicle transfer function, δ EV is the primary frequency modulation coefficient of electric vehicles, T EV is the electric vehicle time response coefficient; The communication model between regions is: Among them, M area1 is the equivalent inertia coefficient of region 1, M area2 is the equivalent inertia coefficient of region 2, D area1 is the equivalent damping coefficient of region 1, D area2 is the equivalent damping coefficient of region 2, ΔP WT is the change in active power of the fan, ΔP PV is the change in photovoltaic active power, θ1 is the transfer coefficient of area 1, θ2 is the transfer coefficient of area 2, θ3 is the transfer coefficient of area 3, Δf1 is the frequency deviation of area 1, Δf PS is the frequency deviation in region 2, Δf IES is the frequency deviation of the power flow in the integrated energy system, ΔP R is the active power variation of thermal power units, M IES is the equivalent inertia coefficient of the comprehensive energy system, D IES is the equivalent damping coefficient of the comprehensive energy system, ΔP E is the change in active energy storage, ΔP CHP is the active power change of the cogeneration device, ΔP RAC is the active power change of the air conditioning system, ΔP EV is the active power variation of the electric vehicle system.

16. The system according to claim 9, wherein the verification unit is used to verify the stable operation capability of the electric energy flow based on the stable operation verification model of the electric energy flow, comprising: The active power stable operation capability index model of the low-carbon urban integrated energy system AP : Among them, P Rated For the grid capacity of low-carbon urban integrated energy system, are the upper and lower boundary values ​​of power fluctuation of electric energy flow, respectively, and ΔP is the active power change of any node in the electric energy flow; The frequency stability operation capability index model of the low-carbon city comprehensive energy system SF : Among them, f Rated The power frequency of the low-carbon city integrated energy system grid, are the upper and lower boundary values ​​of the frequency fluctuation of the power flow, respectively, and Δf is the frequency change of any node in the power flow.

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