Comprehensive energy system optimization scheduling method considering carbon transaction and demand response mechanism

Abstract

The invention discloses an integrated energy system optimal scheduling method considering a carbon transaction and demand response mechanism, and relates to the field of new energy, comprising the following steps: establishing a demand response mechanism model, and optimizing to obtain an energy load curve after demand response; establishing a carbon transaction model, and bringing the carbon emission cost into the total cost of system operation; establishing an optimal scheduling model of the integrated energy system, taking the operation cost of the integrated energy system as a target function, and considering constraints of power balance, wind power output, energy conversion equipment and energy storage equipment; according to the method, a comprehensive energy system optimal scheduling mechanism considering a carbon transaction and demand response mechanism is established, carbon emission and system operation cost are bound by considering a stepped carbon transaction mechanism, and the optimal scheduling result of the comprehensive energy system is obtained. Therefore, the purpose of controlling carbon emission is achieved.

Description

Technical Field

[0001] The present invention relates to the field of new energy, and in particular to an integrated energy system optimization scheduling method taking into account carbon trading and demand response mechanisms. Background Art

[0002] Integrated Energy Systems (IES) is a new type of energy management and technology solution that aims to improve energy efficiency, reduce carbon emissions and optimize energy systems. It integrates multiple forms of energy (such as electricity, heat, cold, gas, hydrogen, etc.) to achieve coordinated optimization in the production, transportation, storage and consumption of energy. After the release and implementation of the "Carbon Peak, Carbon Neutrality" action plan, the State Grid clearly proposed to "actively promote integrated energy services, focus on large public buildings in industrial parks, actively expand energy diagnosis, energy efficiency improvement, multi-energy supply and other integrated energy services, and help improve the terminal energy efficiency of the whole society."

[0003] Carbon trading is a market-based means to reduce greenhouse gas emissions through economic incentives and help achieve climate change goals. It is usually based on the principle of "cap and trade" or "carbon offset". Carbon trading was originally proposed under the framework of the Kyoto Protocol and is one of the important tools for the international community to respond to climate change. Demand response (DR) is a key load management strategy in the power system, which helps achieve a dynamic balance between power supply and demand by incentivizing or regulating the electricity consumption behavior of end users. It is a flexible resource used to promote flexible response on the load side when the pressure on the power grid increases or the electricity price changes, thereby improving the efficiency and stability of the energy system. Summary of the invention

[0004] The purpose of the present invention is to provide a comprehensive energy system optimization scheduling method taking into account carbon trading and demand response mechanisms to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for optimizing the scheduling of an integrated energy system considering carbon trading and demand response mechanisms comprises the following steps:

[0007] Step 1: Establish a demand response mechanism model, and optimize the energy load curve after demand response by considering and calculating the three types of demand response: curtailable, shiftable, and replaceable;

[0008] Step 2: Establish a carbon trading model, collect statistics on the initial carbon quota of the system, as well as the carbon emissions of each device and link in the system, and include the carbon emission cost in the total cost of system operation;

[0009] Step 3: Establish an optimal dispatching model for the integrated energy system, taking the operation cost of the integrated energy system as the objective function, and considering the constraints of power balance, wind power output, energy conversion equipment, and energy storage equipment;

[0010] Step 4, model solving, initialize the parameters of each device in the system, the initial price and time-of-use price of the electricity and gas energy markets, input the load curves of the three energy sources of electricity, heat and gas and wind power output, linearize the optimal scheduling model of the integrated energy system, and solve it to obtain the optimal scheduling result.

[0011] As a further preferred embodiment of the present invention: the demand response mechanism model includes a price-based demand response mechanism model and an alternative demand response mechanism model; the method for establishing the demand response mechanism model is as follows:

[0012] 1) The price-based demand response mechanism model is divided into curtailable load and transferable load. The price demand elasticity matrix is ​​used to describe the relationship between energy price and energy demand. It is composed of price demand elasticity coefficients and is expressed as follows:

[0013]

[0014] Where: ε uv With ε uu are the cross elastic coefficient and the self elastic coefficient (u, v = 1, 2…, t), respectively, and the expression is:

[0015]

[0016] Where: ε t,j is the elasticity coefficient of the load price at time t to j; ΔP t eL P is the load change after demand response at time t; t eL0 is the initial load at time t; Δρ j is the change in electricity price at time j after demand response; is the initial electricity price;

[0017] CL refers to the behavior of users reducing load and adjusting energy consumption according to changes in energy prices and system requirements, and SL refers to the behavior of users shifting their load demand from one time period to another according to energy prices and system requirements;

[0018]

[0019] Where: P t eCL0 is the initial load reduction at time t; is the price elasticity coefficient of CL demand; ρ j is the electricity price at time j;

[0020]

[0021] Where: ΔP t eSL is the change of SL at time t after demand response; P t eSL0 is the initial transferable load at time t; is the SL price demand elasticity coefficient.

[0022] 2) The alternative demand response mechanism model refers to the load that can be replaced by other energy sources:

[0023]

[0024] Where: ΔP t eRL , ΔP t gRL are the replaceable electricity load and the corresponding replaced gas load respectively; ε e,g is the gas-electricity substitution coefficient; v e 、v g The energy released or absorbed when a unit mass of matter is completely converted into electrical energy or gas energy respectively; are the energy utilization efficiencies of electric energy and gas energy, respectively. For this type of load, the maximum replaceable load constraint needs to be considered, and the expression is:

[0025]

[0026] Where: and are the maximum values ​​of replaceable electricity and gas loads respectively;

[0027] After comprehensively considering the three types of demand response, namely, curtailable, removable and replaceable, the user's electricity load is expressed as:

[0028] P t eLDR =P t eL0 +ΔP t eCL +ΔP t eSL +ΔP t eRL (35)

[0029] Where: P t eLDR is the electric load at time t after considering demand response.

[0030] As a further preferred solution of the present invention: the carbon trading model consists of two parts: the initial carbon emission quota and the actual carbon emission amount:

[0031] 1) Initial carbon emission quota

[0032] The calculation formula of the initial carbon emission quota function is:

[0033]

[0034] Where: is the carbon emission quota function of the equipment in the tth period; e is the carbon emission quota coefficient for electricity generation; is the power supply of the equipment in the tth period; h is the carbon emission quota coefficient for heat production; φ h-e is the electrothermal conversion coefficient; is the heat supply of the equipment in the tth period;

[0035] 2) Actual carbon emissions

[0036] The carbon emissions generated by electricity supply and heating are both included in the actual carbon emissions. The carbon emissions function of the equipment in the tth period is:

[0037]

[0038] Where: is the carbon emission of the equipment in the tth period; ω e is the carbon emission coefficient of the unit power supply; ω h is the carbon emission coefficient per unit of heating.

[0039] As a further preferred solution of the present invention: the integrated energy system optimization scheduling model takes the lowest total economic operation cost of the system as the optimization scheduling target, and the power balance of each energy source in the system, internal equipment constraints, and wind power output as constraints, which are as follows:

[0040] 1. Objective function:

[0041] The low-carbon economic dispatch model of the integrated energy park takes the lowest total economic operation cost of the system as the optimization dispatch target. The expression of the total economic operation cost function of the park is:

[0042]

[0043] Where: F total is the total economic operating cost of the system; F buy The cost of purchasing energy; is the carbon trading cost; F op The cost of running the system;

[0044] 4) Energy purchase cost

[0045]

[0046] Where: S T is the set of time periods (T is the total number of time periods); are the prices of electricity and gas purchased by the system from external sources in the tth period, respectively; are the amount of electricity and gas purchased by the system from external sources in the tth period respectively;

[0047] 5) Equipment operating costs

[0048]

[0049] Where: S EGC is a collection of energy production and consumption equipment; i,t is the operating cost of the equipment in the tth period;

[0050] 6) Carbon trading costs

[0051] The net carbon emissions of the system, i.e. the carbon emission rights trading amount, is calculated and determined by the initial carbon emissions and actual carbon emissions of the comprehensive energy system. Considering the use of a tiered carbon trading mechanism, the purchase of carbon emission rights quotas is divided into multiple intervals:

[0052]

[0053] Where: E Δ is the IES net carbon emissions; is the actual carbon emission of IES; E0 is the initial carbon emission quota of IES; λ is the carbon trading base price; l is the length of the carbon emission interval; α is the price growth rate;

[0054] (1) Initial carbon emission quota of the park

[0055] The calculation formula for the park’s initial carbon emission quota is as follows:

[0056]

[0057] Where: S0 is the set of devices that allocate carbon quotas. In this model, the devices that allocate initial carbon quotas include cogeneration units and gas boilers; The carbon emission quota allocated to the equipment for electricity and heat generation in the tth period;

[0058] (2) Actual carbon emissions of the park

[0059] The actual carbon emissions calculation formula of the park is as follows

[0060]

[0061] Where: It is a collection of carbon emission equipment. In this model, there are cogeneration units and gas boilers. The methane reactor absorbs part of CO2 during the process of converting hydrogen into natural gas. Considering the carbon capture effect of the methane reactor, is the carbon consumption of the methane reactor in the tth period;

[0062] 2. Constraints

[0063] 2) System-level constraints

[0064] It is required that within one operation cycle of the integrated energy system, the internal electricity, gas, heat and hydrogen power must meet the following balance constraints respectively:

[0065]

[0066] Where: S N For equipment collection; are the gas and hydrogen supply of the equipment in the tth period, respectively; are the consumption of electricity, gas, heat and hydrogen by the equipment in the tth period respectively;

[0067] 2) Device-level constraints

[0068] (1) Wind power generation

[0069]

[0070] Where: is the electrical power of device i in the tth period, P i min , P i max are the minimum and maximum output power of device i, respectively, c coal is the unit coal cost;

[0071] (2) Power-to-gas

[0072] The two-stage model consists of two equipment models: an electrolyzer and a methane reactor. First, the electrolyzer uses electricity to convert water into hydrogen, and then the methane reactor converts hydrogen into natural gas, which absorbs some CO2 in this process.

[0073] The electrolyzer converts electrical energy into hydrogen energy, and its model expression is:

[0074]

[0075] Where: is the conversion efficiency of the electrolyzer; P i ELmax The upper limit of the electric energy input to the electrolyzer;

[0076] The methane reactor converts hydrogen energy into gas energy, and its model expression is:

[0077]

[0078] Where: The efficiency of hydrogen fuel cell in converting hydrogen into electricity; P i HFCmax The upper limit of hydrogen input for hydrogen fuel cells;

[0079] (4) Cogeneration equipment

[0080] The model expression of hydrogen blending in fuel gas of cogeneration equipment is as follows:

[0081]

[0082] Where: κ i,t is the hydrogen blending ratio of the fuel gas of the cogeneration unit in the tth period; L mix They are the lower calorific values ​​of hydrogen, natural gas and mixed gas respectively; is the mixed gas input power of the cogeneration unit in the tth period;

[0083] Assuming that the sum of the electricity and heat production efficiencies of the cogeneration unit is a constant, the heat-to-electricity ratio can be adjusted within a certain range, so that the electricity-to-heat output ratio can be flexibly adjusted according to the real-time electricity-to-heat demand. The model expression is as follows:

[0084]

[0085] Where: is the overall efficiency of the CHP unit; are the upper and lower limits of the heat-to-electricity ratio of the cogeneration unit; P i CHPmax The maximum value of the mixed gas input power of the cogeneration unit;

[0086] (5) Gas boiler

[0087]

[0088] Where: P is the efficiency of gas-to-heat conversion of gas boiler; i GBmax The upper limit of gas input for gas boilers;

[0089] (6) Energy storage device

[0090] Unified modeling of electric, thermal, and hydrogen energy storage devices;

[0091]

[0092] Where: are the capacity percentages of the electric, thermal and hydrogen energy storage equipment in the tth period respectively; P i S is the rated capacity of the corresponding energy storage device; They are the upper and lower limits of the capacity percentage of electric, thermal and hydrogen energy storage equipment, respectively; are the charging and discharging power of the corresponding energy storage equipment in the tth time period respectively; They are the charging and discharging efficiency of electrical, thermal and hydrogen energy storage devices respectively; are binary variables, which are the charging and discharging state parameters of the corresponding energy storage device in the tth period, Indicates that it is in charging state. Indicates that it is in a state of releasing energy; They are respectively the maximum single charging and discharging power of the corresponding energy storage equipment.

[0093] Compared with the prior art, the present invention has the following beneficial effects:

[0094] (1) The present invention establishes an integrated energy system optimization scheduling mechanism that takes into account carbon trading and demand response mechanisms. By considering the tiered carbon trading mechanism, carbon emissions are tied to system operating costs, thereby achieving the purpose of controlling carbon emissions;

[0095] (2) By considering the three types of demand response, namely curtailable, relocatable and replaceable, the "peak-shaving and valley-filling" effect of flexible load is fully utilized, making the load curve smoother and reducing the difference between peak and valley. The transfer, reduction and replacement of energy demand are achieved, the utilization rate of wind power consumption and internal resources is improved, and the system's wind curtailment cost and energy purchase cost are effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] Figure 1 This is a schematic diagram of the energy supply structure of an integrated energy system according to a preferred embodiment of the present invention.

[0097] Figure 2 The figure is a flow chart of a method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0098] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0099] Figure 1 FIG. 1 is a schematic diagram of the energy supply structure of a comprehensive energy system according to a preferred embodiment of the present invention. Figure 1As shown, the framework of the integrated energy system couples four energy sources: electricity, heat, gas, and hydrogen. The cogeneration unit can burn natural gas and hydrogen to convert them into electricity and heat energy, and the hydrogen fuel cell can convert hydrogen energy into electricity, while working with wind power generation and batteries to meet the system's electricity demand. When the power supply is insufficient, purchasing electricity from the upper-level power grid is also considered. In addition to the cogeneration unit, the gas boiler burns natural gas to convert it into heat energy, and together with the heat storage tank, it meets the system's thermal load demand. The system's gas demand is provided by the power-to-gas device and purchased natural gas. The hydrogen demand is provided by the electrolyzer and hydrogen storage tank in the power-to-gas process, and hydrogen energy is converted into other forms of energy in the system through various equipment.

[0100] See also Figure 2 In an embodiment of the present invention, a comprehensive energy system optimization scheduling method considering carbon trading and demand response mechanism includes the following steps:

[0101] Step 1: Establish a demand response mechanism model, and optimize the energy load curve after demand response by considering and calculating the three types of demand response: curtailable, shiftable, and replaceable;

[0102] Step 2: Establish a carbon trading model, collect statistics on the initial carbon quota of the system, as well as the carbon emissions of each device and link in the system, and include the carbon emission cost in the total cost of system operation;

[0103] Step 3: Establish an optimal dispatching model for the integrated energy system, taking the operation cost of the integrated energy system as the objective function, and considering the constraints of power balance, wind power output, energy conversion equipment, and energy storage equipment;

[0104] Step 4, model solving, initialize the parameters of each device in the system, the initial price and time-of-use price of the electricity and gas energy markets, input the load curves of the three energy sources of electricity, heat and gas and wind power output, linearize the optimal scheduling model of the integrated energy system, and solve it to obtain the optimal scheduling result.

[0105] As a further preferred embodiment of the present invention: the demand response mechanism model includes a price-based demand response mechanism model and an alternative demand response mechanism model; the method for establishing the demand response mechanism model is as follows:

[0106] 1) The price-based demand response mechanism model is divided into curtailable load and transferable load. The price demand elasticity matrix is ​​used to describe the relationship between energy price and energy demand. It is composed of price demand elasticity coefficients and is expressed as follows:

[0107]

[0108] Where: ε uv With ε uu are the cross elastic coefficient and the self elastic coefficient (u, v = 1, 2…, t), respectively, and the expression is:

[0109]

[0110] Where: ε t,j is the elasticity coefficient of the load price at time t to j; ΔP t eL P is the load change after demand response at time t; t eL0 is the initial load at time t; Δρ j is the change in electricity price at time j after demand response; is the initial electricity price;

[0111] CL refers to the behavior of users reducing load and adjusting energy consumption according to changes in energy prices and system requirements, and SL refers to the behavior of users shifting their load demand from one time period to another according to energy prices and system requirements;

[0112]

[0113] Where: P t eCL0 is the initial load reduction at time t; is the price elasticity coefficient of CL demand; ρ j is the electricity price at time j;

[0114]

[0115] Where: ΔP t eSL is the change of SL at time t after demand response; P t eSL0 is the initial transferable load at time t; is the SL price demand elasticity coefficient.

[0116] 2) The alternative demand response mechanism model refers to the load that can be replaced by other energy sources:

[0117] ΔP t eRL =-ε e,g ΔP t gRL (59)

[0118]

[0119] Where: ΔP t eRL , ΔP t gRL are the replaceable electricity load and the corresponding replaced gas load respectively; ε e,g is the gas-electricity substitution coefficient; v e 、v gThe energy released or absorbed when a unit mass of matter is completely converted into electrical energy or gas energy respectively; are the energy utilization efficiencies of electric energy and gas energy, respectively. For this type of load, the maximum replaceable load constraint needs to be considered, and the expression is:

[0120]

[0121] Where: and are the maximum values ​​of replaceable electricity and gas loads respectively;

[0122] After comprehensively considering the three types of demand response, namely, curtailable, removable and replaceable, the user's electricity load is expressed as:

[0123] P t eLDR =P t eL0 +ΔP t eCL +ΔP t eSL +ΔP t eRL (62)

[0124] Where: P t eLDR is the electric load at time t after considering demand response.

[0125] The carbon trading model consists of two parts: initial carbon emission quota and actual carbon emissions:

[0126] 1) Initial carbon emission quota

[0127] The calculation formula of the initial carbon emission quota function is:

[0128]

[0129] Where: is the carbon emission quota function of the equipment in the tth period; e is the carbon emission quota coefficient for electricity generation; is the power supply of the equipment in the tth period; h is the carbon emission quota coefficient for heat production; φ h-e is the electrothermal conversion coefficient; is the heat supply of the equipment in the tth period;

[0130] 2) Actual carbon emissions

[0131] The carbon emissions generated by electricity supply and heating are both included in the actual carbon emissions. The carbon emissions function of the equipment in the tth period is:

[0132]

[0133] Where: is the carbon emission of the equipment in the tth period; ω e is the carbon emission coefficient of the unit power supply; ω h is the carbon emission coefficient per unit of heating.

[0134] The optimization dispatch model of the integrated energy system takes the lowest total economic operation cost of the system as the optimization dispatch target, and the power balance of each energy source in the system, internal equipment constraints, and wind power output as constraints, as follows:

[0135] 1. Objective function:

[0136] The low-carbon economic dispatch model of the integrated energy park takes the lowest total economic operation cost of the system as the optimization dispatch target. The expression of the total economic operation cost function of the park is:

[0137]

[0138] Where: F total is the total economic operating cost of the system; F buy The cost of purchasing energy; is the carbon trading cost; F op The cost of running the system;

[0139] 7) Energy purchase cost

[0140]

[0141] Where: S T is the set of time periods (T is the total number of time periods); are the prices of electricity and gas purchased by the system from external sources in the tth period, respectively; are the amount of electricity and gas purchased by the system from external sources in the tth period respectively;

[0142] 8) Equipment operating costs

[0143]

[0144] Where: S EGC is a collection of energy production and consumption equipment; i,t is the operating cost of the equipment in the tth period;

[0145] 9) Carbon trading costs

[0146] The net carbon emissions of the system, i.e. the carbon emission rights trading amount, is calculated and determined by the initial carbon emissions and actual carbon emissions of the comprehensive energy system. Considering the use of a tiered carbon trading mechanism, the purchase of carbon emission rights quotas is divided into multiple intervals:

[0147]

[0148]

[0149] Where: E Δ is the IES net carbon emissions; is the actual carbon emission of IES; E0 is the initial carbon emission quota of IES; λ is the carbon trading base price; l is the length of the carbon emission interval; α is the price growth rate;

[0150] (1) Initial carbon emission quota of the park

[0151] The calculation formula for the park’s initial carbon emission quota is as follows:

[0152]

[0153] Where: S0 is the set of devices that allocate carbon quotas. In this model, the devices that allocate initial carbon quotas include cogeneration units and gas boilers; is the carbon emission quota allocated to the equipment for electricity and heat generation in the tth period;

[0154] (2) Actual carbon emissions of the park

[0155] The actual carbon emissions calculation formula of the park is as follows

[0156]

[0157] Where: It is a collection of carbon emission equipment. In this model, there are cogeneration units and gas boilers. The methane reactor absorbs part of CO2 during the process of converting hydrogen into natural gas. Considering the carbon capture effect of the methane reactor, is the carbon consumption of the methane reactor in the tth period;

[0158] 2. Constraints

[0159] 3) System-level constraints

[0160] It is required that within one operation cycle of the integrated energy system, the internal electricity, gas, heat and hydrogen power must meet the following balance constraints respectively:

[0161]

[0162] Where: S N For equipment collection; are the gas and hydrogen supply of the equipment in the tth period, respectively; are the consumption of electricity, gas, heat and hydrogen by the equipment in the tth period respectively;

[0163] 2) Device-level constraints

[0164] (1) Wind power generation

[0165]

[0166] Where: is the electrical power of device i in the tth period, P i min , P i max are the minimum and maximum output power of device i, respectively, c coal is the unit coal cost;

[0167] (2) Power-to-gas

[0168] The two-stage model consists of two equipment models: an electrolyzer and a methane reactor. First, the electrolyzer uses electricity to convert water into hydrogen, and then the methane reactor converts hydrogen into natural gas, which absorbs some CO2 in this process.

[0169] The electrolyzer converts electrical energy into hydrogen energy, and its model expression is:

[0170]

[0171] Where: is the conversion efficiency of the electrolyzer; P i ELmax The upper limit of the electric energy input to the electrolyzer;

[0172] The methane reactor converts hydrogen energy into gas energy, and its model expression is:

[0173]

[0174] Where: The efficiency of hydrogen fuel cell in converting hydrogen into electricity; P i HFCmax The upper limit of hydrogen input for hydrogen fuel cells;

[0175] (4) Cogeneration equipment

[0176] The model expression of hydrogen blending in fuel gas of cogeneration equipment is as follows:

[0177]

[0178] Where: κ i,t is the hydrogen blending ratio of the fuel gas of the cogeneration unit in the tth period; L mix They are the lower calorific values ​​of hydrogen, natural gas and mixed gas respectively; is the mixed gas input power of the cogeneration unit in the tth period;

[0179] Assuming that the sum of the electricity and heat production efficiencies of the cogeneration unit is a constant, the heat-to-electricity ratio can be adjusted within a certain range, so that the electricity-to-heat output ratio can be flexibly adjusted according to the real-time electricity-to-heat demand. The model expression is as follows:

[0180]

[0181] Where: is the overall efficiency of the CHP unit; are the upper and lower limits of the heat-to-electricity ratio of the cogeneration unit; P i CHPmax The maximum value of the mixed gas input power of the cogeneration unit;

[0182] (5) Gas boiler

[0183]

[0184] Where: P is the efficiency of gas-to-heat conversion of gas boiler; i GBmax The upper limit of gas input for gas boilers;

[0185] (6) Energy storage device

[0186] Unified modeling of electric, thermal, and hydrogen energy storage devices;

[0187]

[0188]

[0189] Where: are the capacity percentages of the electric, thermal and hydrogen energy storage equipment in the tth period respectively; P i S is the rated capacity of the corresponding energy storage device; They are the upper and lower limits of the capacity percentage of electric, thermal and hydrogen energy storage equipment, respectively; are the charging and discharging power of the corresponding energy storage equipment in the tth time period respectively; They are the charging and discharging efficiency of electrical, thermal and hydrogen energy storage devices respectively; are binary variables, which are the charging and discharging state parameters of the corresponding energy storage device in the tth period, Indicates that it is in charging state. Indicates that it is in a state of releasing energy; They are respectively the maximum single charging and discharging power of the corresponding energy storage equipment.

[0190] The following is an explanation of the two links: 1) establishment of an integrated energy system model and 2) alternative demand response:

[0191] 1) Establishment of comprehensive energy system model

[0192] The equipment models included in the comprehensive energy system defined in the present invention are wind turbines, gas boilers, electrolyzer equipment, methane reactor equipment, hydrogen fuel cell equipment, cogeneration units, and energy storage equipment. Comprehensive energy system models containing other different types of equipment may also be used.

[0193] 2) Alternative demand response

[0194] The alternative demand response defined in the present invention analyzes the substitution between electricity and gas energy. Each integrated energy system can set different alternative demand responses according to the types of energy it contains, the mutual conversion between energies and the energy purchase demand, so as to reasonably adjust the energy use strategy.

[0195] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0196] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A comprehensive energy system optimization scheduling method considering carbon trading and demand response mechanism, characterized in that: The steps include: Step 1: Establish a demand response mechanism model, and optimize the energy load curve after demand response by considering and calculating the three types of demand response: curtailable, shiftable, and replaceable; Step 2: Establish a carbon trading model, collect statistics on the initial carbon quota of the system, as well as the carbon emissions of each device and link in the system, and include the carbon emission cost in the total cost of system operation; Step 3: Establish an optimal dispatching model for the integrated energy system, taking the operation cost of the integrated energy system as the objective function, and considering the constraints of power balance, wind power output, energy conversion equipment, and energy storage equipment; Step 4, model solving, initialize the parameters of each device in the system, the initial price and time-of-use price of the electricity and gas energy markets, input the load curves of the three energy sources of electricity, heat and gas and wind power output, linearize the optimal scheduling model of the integrated energy system, and solve it to obtain the optimal scheduling result.

2. According to claim 1, a comprehensive energy system optimization scheduling method considering carbon trading and demand response mechanism is characterized in that: The demand response mechanism model includes a price-based demand response mechanism model and an alternative demand response mechanism model; the method for establishing the demand response mechanism model is as follows: 1) The price-based demand response mechanism model is divided into curtailable load and transferable load. The price demand elasticity matrix is ​​used to describe the relationship between energy price and energy demand. It is composed of price demand elasticity coefficients and is expressed as follows: Where: ε uv With ε uu are the cross elastic coefficient and the self elastic coefficient (u, v = 1, 2…, t), respectively, and the expression is: Where: ε t,j is the elasticity coefficient of the load price at time t to j; is the load change after demand response at time t; is the initial load at time t; Δρ j is the change in electricity price at time j after demand response; is the initial electricity price; CL refers to the behavior of users reducing load and adjusting energy consumption according to changes in energy prices and system requirements, and SL refers to the behavior of users shifting their load demand from one time period to another according to energy prices and system requirements; Where: is the initial load reduction at time t; is the price elasticity coefficient of CL demand; ρ j is the electricity price at time j; Where: is the change in SL at time t after demand response; is the initial transferable load at time t; is the SL price demand elasticity coefficient; 2) The alternative demand response mechanism model refers to the load that can be replaced by other energy sources: Where: They are the replaceable electricity load and the corresponding replaced gas load respectively; ε e,g is the gas-electricity substitution coefficient; v e 、v g The energy released or absorbed when a unit mass of matter is completely converted into electrical energy or gas energy respectively; are the energy utilization efficiencies of electric energy and gas energy, respectively. For this type of load, the maximum replaceable load constraint needs to be considered, and the expression is: Where: and are the maximum values ​​of replaceable electricity and gas loads respectively; After comprehensively considering the three types of demand response, namely, curtailable, removable and replaceable, the user's electricity load is expressed as: Where: is the electric load at time t after considering demand response.

3. A comprehensive energy system optimization scheduling method considering carbon trading and demand response mechanism according to claim 1 or 2, characterized in that: The carbon trading model consists of two parts: initial carbon emission quota and actual carbon emissions: 1) Initial carbon emission quota The calculation formula of the initial carbon emission quota function is: Where: is the carbon emission quota function of the equipment in the tth period; e is the carbon emission quota coefficient for electricity generation; is the power supply of the equipment in the tth period; h is the carbon emission quota coefficient for heat production; φ h-e is the electrothermal conversion coefficient; is the heat supply of the equipment in the tth period; 2) Actual carbon emissions The carbon emissions generated by electricity supply and heating are both included in the actual carbon emissions. The carbon emissions function of the equipment in the tth period is: Where: is the carbon emission of the equipment in the tth period; ω e is the carbon emission coefficient of the unit power supply; ω h is the carbon emission coefficient per unit of heating.

4. The method for optimizing and scheduling an integrated energy system considering carbon trading and demand response mechanism according to claim 3 is characterized in that: The optimization dispatch model of the integrated energy system takes the lowest total economic operation cost of the system as the optimization dispatch target, and the power balance of each energy source in the system, internal equipment constraints, and wind power output as constraints, which are as follows:

1. Objective function: The low-carbon economic dispatch model of the integrated energy park takes the lowest total economic operation cost of the system as the optimization dispatch target. The expression of the total economic operation cost function of the park is: Where: F total is the total economic operating cost of the system; F buy The cost of purchasing energy; is the carbon trading cost; F op The cost of running the system; 1) Energy purchase cost Where: S T is the set of time periods (T is the total number of time periods); are the prices of electricity and gas purchased by the system from external sources in the tth period, respectively; are the amount of electricity and gas purchased by the system from external sources in the tth period respectively; 2) Equipment operating costs Where: S EGC is a collection of energy production and consumption equipment; i,t is the operating cost of the equipment in the tth period; 3) Carbon trading costs The net carbon emissions of the system, i.e. the carbon emission rights trading amount, is determined by calculating the initial carbon emissions and actual carbon emissions of the comprehensive energy system. Considering the use of a tiered carbon trading mechanism, the purchase of carbon emission rights quotas is divided into multiple intervals: Where: E Δ is the IES net carbon emissions; is the actual carbon emission of IES; E0 is the initial carbon emission quota of IES; λ is the carbon trading base price; l is the length of the carbon emission interval; α is the price growth rate; (1) Initial carbon emission quota of the park The calculation formula for the park’s initial carbon emission quota is as follows: Where: S0 is the set of devices that allocate carbon quotas. In this model, the devices that allocate initial carbon quotas include cogeneration units and gas boilers; The carbon emission quota allocated to the equipment for electricity and heat generation in the tth period; (2) Actual carbon emissions of the park The actual carbon emissions calculation formula of the park is as follows Where: It is a collection of carbon emission equipment. In this model, there are cogeneration units and gas boilers. The methane reactor absorbs part of CO2 during the process of converting hydrogen into natural gas. Considering the carbon capture effect of the methane reactor, is the carbon consumption of the methane reactor in the tth period; 2. Constraints 1) System-level constraints It is required that within one operation cycle of the integrated energy system, the internal electricity, gas, heat and hydrogen power must meet the following balance constraints respectively: Where: S N For equipment collection; are the gas and hydrogen supply of the equipment in the tth period, respectively; are the consumption of electricity, gas, heat and hydrogen by the equipment in the tth period respectively; 2) Device-level constraints (1) Wind power generation Where: is the electrical power of device i in the tth period, are the minimum and maximum output power of device i, respectively, c coal is the unit coal cost; (2) Power-to-gas The two-stage model consists of two equipment models: an electrolyzer and a methane reactor. First, the electrolyzer uses electricity to convert water into hydrogen, and then the methane reactor converts hydrogen into natural gas, which absorbs some CO2 in this process. The electrolyzer converts electrical energy into hydrogen energy, and its model expression is: Where: is the conversion efficiency of the electrolyzer; The upper limit of the electric energy input to the electrolyzer; The methane reactor converts hydrogen energy into gas energy, and its model expression is: Where: The efficiency of hydrogen conversion into electricity for hydrogen fuel cells; The upper limit of hydrogen input for hydrogen fuel cells; (4) Cogeneration equipment The model expression of hydrogen blending in fuel gas of cogeneration equipment is as follows: Where: κ i,t is the hydrogen blending ratio of the fuel gas of the cogeneration unit in the tth period; L mix They are the lower calorific values ​​of hydrogen, natural gas and mixed gas respectively; is the mixed gas input power of the cogeneration unit in the tth period; Assuming that the sum of the electricity and heat production efficiencies of the cogeneration unit is a constant, the heat-to-electricity ratio can be adjusted within a certain range, so that the electricity-to-heat output ratio can be flexibly adjusted according to the real-time electricity-to-heat demand. The model expression is as follows: Where: is the overall efficiency of the CHP unit; They are the upper and lower limits of the heat-to-electricity ratio of the cogeneration unit respectively; The maximum value of the mixed gas input power of the cogeneration unit; (5) Gas boiler Where: The efficiency of gas-to-heat conversion of gas boiler; The upper limit of gas input for gas boilers; (6) Energy storage device Unified modeling of electric, thermal, and hydrogen energy storage devices; Where: are the capacity percentages of the electric, thermal and hydrogen energy storage equipment in the tth period, respectively; is the rated capacity of the corresponding energy storage device; They are the upper and lower limits of the capacity percentage of electric, thermal and hydrogen energy storage equipment, respectively; are the charging and discharging power of the corresponding energy storage equipment in the tth time period respectively; They are the charging and discharging efficiency of electrical, thermal and hydrogen energy storage devices respectively; are binary variables, which are the charging and discharging state parameters of the corresponding energy storage device in the tth period, Indicates that it is in charging state. Indicates that it is in a state of releasing energy; They are respectively the maximum single charging and discharging power of the corresponding energy storage equipment.

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