Island comprehensive energy low-carbon economic dispatching method integrated with hydrogen energy and green certificate-carbon transaction

Abstract

The invention discloses an island comprehensive energy low-carbon economic dispatching method integrated with hydrogen energy and green certificate-carbon transaction, and the method comprises the following steps: 1, constructing an island comprehensive energy system which comprises energy supply equipment, energy storage equipment and a carbon capture device; 2, introducing a green certificate-carbon transaction joint mechanism which comprises a carbon transaction mechanism and a green certificate mechanism; the green certificate mechanism generates a green certificate based on the new energy generating capacity, and the carbon transaction mechanism calculates the carbon transaction cost by adopting a stepped carbon transaction strategy and counteracts a part of carbon emission through the green certificate; step 3, with the purpose of minimizing the comprehensive operation cost of the island comprehensive energy system, establishing an optimal scheduling model, the operation cost including natural gas purchase cost, carbon transaction cost, green certificate cost, wind curtailment punishment cost, carbon sequestration cost and demand response compensation cost; and 4, solving the optimal scheduling model by using a solver, generating a low-carbon economic scheduling scheme, and optimizing output and energy storage charging and discharging strategies of each device.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive energy utilization technology, specifically a method for low-carbon economic dispatch of island comprehensive energy that integrates hydrogen energy and green certificate-carbon trading. Background Technology

[0002] Integrated energy systems, as a technological carrier for meeting diverse energy demands and achieving multi-energy synergy and efficient utilization, are of great significance for enhancing renewable energy absorption capacity and reducing carbon emissions. my country has vast sea areas and numerous islands, making a reliable and clean energy supply crucial for marine development. Adhering to the principles of stable power supply and developing clean energy, fully utilizing nearby new energy sources, reducing the operating costs of island microgrids, improving the utilization rate of renewable energy, and effectively ensuring the maximization of residential load demand and economic benefits are key measures for promoting island development in the future. Given the abundant renewable energy resources of islands and the advantages of hydrogen energy as a clean and adaptable energy carrier, constructing independent island integrated energy systems (IIES) based on the diversified utilization of hydrogen energy is a key path to optimizing the energy structure, improving the absorption rate of new energy sources, achieving electricity-carbon balance, and promoting the green transformation of island energy.

[0003] Hydrogen energy, with its high energy density, lack of pollution, ease of production, and zero carbon emissions, is expected to play a significant role in Integrated Energy Systems (IES). While existing technologies have explored the economic viability of hydrogen energy utilization, laying the foundation for wind power integration, there is relatively little discussion on the synergistic optimization of hydrogen-hydrogen-carbon energy integration into island microgrids. Under the constraint of "dual carbon" objectives, my country has established market mechanisms such as Carbon Emission Trading (CET) and Green Certificate Trading (GCT) to guide resource allocation towards renewable energy and suppress traditional thermal power, aiming to gradually shift the energy system towards a market-driven model. Currently, CET and GCT are widely used in Integrated Energy Systems (IES). While existing technologies have achieved some success in promoting renewable energy integration and reducing system carbon emissions through GCT and CET mechanisms, they have neglected the internal connection between the two, failing to fully leverage the low-carbon operation capabilities of IES. Therefore, it is necessary to further explore the correlation between green certificates and carbon trading mechanisms, analyze their coupled application's impact on IES, and promote their application in IIES. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a low-carbon economic dispatch method for integrated island energy that integrates hydrogen energy and green certificate-carbon trading. By integrating diversified utilization of hydrogen energy and green certificate-carbon joint trading mechanism, it solves the problems of insufficient renewable energy consumption, high carbon emissions, and high operating costs in integrated island energy systems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for integrated low-carbon economic dispatch of island energy, incorporating hydrogen energy and green certificate-carbon trading, includes the following steps: Step 1: Construct an integrated island energy system, including energy supply equipment, energy storage equipment, and carbon capture devices; wherein, the energy supply equipment includes offshore wind turbines, hydrogen electrolysis equipment, methane reactors, hydrogen fuel cells, gas boilers, refrigeration equipment, and seawater desalination devices; the energy storage equipment includes hydrogen storage tanks and hydrogen fuel cells; the carbon capture device is used to capture carbon dioxide and supply it to the methane reactor as a carbon source; Step 2: Introduce a green certificate-carbon trading joint mechanism, including a carbon trading mechanism and a green certificate mechanism; the green certificate mechanism generates green certificates based on new energy power generation, and the carbon trading mechanism uses a tiered carbon trading strategy to calculate carbon trading costs and offsets part of the carbon emissions through green certificates; Step 3: To minimize the overall operating cost of the island's integrated energy system, an optimized scheduling model is established. The operating cost includes natural gas purchase cost, carbon trading cost, green certificate cost, wind curtailment penalty cost, carbon storage cost, and demand response compensation cost. Step 4: Use the solver to solve the optimized scheduling model, generate a low-carbon economic scheduling scheme, and optimize the output of each device and the charging and discharging strategy of energy storage.

[0006] Furthermore, the hydrogen electrolysis equipment employs an electrolyzer, and the operating model of the electrolyzer is represented as follows: In the formula: for Hydrogen production capacity of the electrolyzer at any given time; The efficiency of an electrolyzer in converting electrical energy into hydrogen energy; for The power consumption of the electrolytic cell at all times; and These represent the maximum and minimum values ​​of the change in power consumption per unit time in the electrolytic cell; and These represent the maximum and minimum power consumption of the electrolytic cell, respectively. The operating model of the methane reactor is represented as follows: In the formula: for Constantly supplying hydrogen energy to the methane generator; for It continuously outputs the power of natural gas; The conversion efficiency of the methane generator; and These represent the maximum and minimum values ​​of the input hydrogen energy, respectively. The coefficient for calculating CO2; and These represent the maximum and minimum values ​​for the methane generator ramp-up, respectively. For methane generator in The amount of CO2 consumed at any given time; The operating model of the hydrogen fuel cell is represented as follows: In the formula: and They are respectively The output power of the hydrogen fuel cell in terms of electrical and thermal energy at any given time; The input power of hydrogen energy; and These are the electrical and thermal conversion efficiencies, respectively. and These are the maximum and minimum values ​​of the thermoelectric ratio, respectively. and These represent the maximum and minimum values ​​of the hydrogen energy input power, respectively. and These represent the maximum and minimum values ​​of the change in input hydrogen power per unit time; The operating model of the gas-fired boiler is as follows: In the formula: for The heat output capacity of the gas-fired boiler at all times; The heat production efficiency of a gas-fired boiler; This refers to the gas consumption power of the gas-fired boiler. This refers to the calorific value of natural gas. and These are the maximum and minimum gas consumption power of the gas-fired boiler, respectively. and These represent the maximum and minimum values ​​of the change in gas consumption power per unit time, respectively. The refrigeration equipment includes an absorption chiller and an electric chiller, and the refrigeration and constraint of the refrigeration equipment are represented as follows: In the formula: and They are respectively The cooling capacity and maximum cooling capacity of the constant-time absorption chiller; The refrigeration efficiency of an absorption chiller; and They are respectively The cooling capacity and maximum cooling capacity of the instantaneous refrigerator; The refrigeration efficiency of the electric chiller; The seawater desalination device uses reverse osmosis for seawater desalination and purification, and its energy consumption is: In the formula: The power consumption of DH; The conversion efficiency of the seawater desalination unit; The energy consumption of the carbon capture device includes stationary energy consumption and operational energy consumption, expressed as follows: In the formula: For carbon capture equipment The electrical power consumed in constantly capturing CO2; and They are respectively Basic and operating energy consumption of real-time carbon capture equipment; The power consumption per unit of CO2 captured; For carbon capture equipment The total amount of CO2 captured at any given time; and They are respectively The amount of CO2 consumed during methanation and the amount of CO2 stored at any given time; for The amount of CO2 emitted by the carbon-producing unit at any given time; The carbon capture rate of the carbon capture equipment.

[0007] The operating constraints of the energy storage device are as follows: In the formula: The energy sources are hydrogen energy and electrical energy; for Storing energy at all times; To maximize energy storage; and They are respectively Constant charging and discharging power; and They are respectively The charging and discharging efficiency of energy storage devices at all times; and These are the charging and discharging state variables, respectively, and are Boolean variables.

[0008] Furthermore, the island integrated energy system also includes a combined heat and power (CHP) unit, the operating model of which is as follows: In the formula: The power generation capacity of the combined heat and power (CHP) unit; This refers to the gas consumption of a combined heat and power (CHP) unit. The power generation efficiency of the combined heat and power (CHP) unit; This refers to the calorific value of natural gas. The electrothermal operating characteristics of the combined heat and power unit are as follows: In the formula: and for The electrical and thermal output power of the cogeneration unit at all times; and for The maximum and minimum values ​​of electrical energy output power at any given time; and for The maximum and minimum values ​​of thermal energy output power at any given time; for The operating status of the cogeneration unit at all times; , , and This refers to the corresponding electrical energy output of a combined heat and power (CHP) unit under different thermal energy output conditions. , , and This refers to the corresponding heat output of a combined heat and power unit under different electrical energy outputs. The start-up and shutdown status and ramp-up limits of the combined heat and power unit are represented as follows: In the formula: for The startup status of the cogeneration unit at all times; for The state of being constantly off; and These represent the maximum and minimum ramp rates of the combined heat and power (CHP) unit.

[0009] Furthermore, in the aforementioned green certificate-carbon trading joint mechanism, the total carbon emissions of the island integrated energy system are: in: For carbon emission rights; The total carbon emissions of the island's integrated energy system; The amount of carbon emissions that can be offset by green certificates; The green certificate quota required for microgrids; The total carbon allowance for the island's integrated energy system; the carbon trading cost after offsetting carbon emissions with new energy sources, based on carbon trading costs and green certificate costs, and: Carbon trading costs are calculated using a tiered system: In the formula: Carbon trading costs for island integrated energy systems; This serves as the base price for carbon trading; The percentage increase in transaction price; The interval length; For carbon emission rights; The cost of green certificates is calculated using a tiered approach: In the formula: The cost of green certificates borne by the island's integrated energy system; The base price for green certificate trading; The percentage increase in transaction price; The interval length; The amount of green certificates that can be used for green certificate trading.

[0010] Furthermore, the objective function of the optimized scheduling model is: in: in: Cost of purchasing natural gas; The cost of curtailing wind power; For carbon trading costs; Cost of carbon sequestration; Cost of green certificates; To compensate for costs in response to demand; The price at which gas is purchased from the natural gas network; for Real-time gas purchase capacity; The penalty cost per unit of energy curtailment; and They are respectively Unabsorbed wind and solar power; Unit cost of carbon sequestration; for Carbon emissions at any given time; , and Compensation coefficients for unit transferred electrical load and unit power cut-off and heat load, respectively; For transferable electrical loads; and These respectively indicate that the electrical and thermal loads can be reduced; The constraints of the optimized scheduling model include constraints on energy interaction with the external environment, power balance constraints, carbon quota constraints, constraints on the number of green certificates held by microgrids, and constraints on the comprehensive demand response of electricity and heat.

[0011] Furthermore, the energy interaction constraint with the external environment is expressed as: In the formula: and They are respectively The amount of gas to be purchased from the outside world at all times, and its upper limit.

[0012] Furthermore, the power balance constraint is as follows: In the formula: for New energy sources are always contributing their power; , as well as , They are respectively The charging and discharging power of hydrogen storage tanks and electrical energy storage at all times; for The cold load at any time.

[0013] Furthermore, the carbon quota constraint is as follows: In the formula: Carbon quotas for combined heat and power units; For the entire scheduling cycle; and These are the benchmarks for carbon emission allocation per unit of electricity and per unit of heat, respectively. Carbon quotas for gas-fired boilers; This refers to the output thermal power of the gas-fired boiler. The total carbon allowance for the island's integrated energy system; The constraint on the number of green certificates held by the microgrid is as follows: In the formula: The green certificate quota required for microgrids; This refers to the green certificate quantity quota coefficient; The number of green certificates obtained for microgrid renewable energy power generation; This is the conversion coefficient between new energy power generation and the number of green certificates; for At all times, the new energy source outputs electrical power; The amount of green certificates that can be used for green certificate trading.

[0014] Furthermore, the comprehensive electrothermal demand response constraint is as follows: In the formula: and These are the original electrical and thermal loads, respectively; and These are the electrical and thermal loads following the demand response; and These respectively indicate that the electrical and thermal loads can be reduced; For transferable electrical loads; and These can reduce the electrical and thermal load coefficients, respectively. This is the transferable electrical load factor.

[0015] Furthermore, the solver is a CPLEX solver, and the model is solved based on the MATLAB platform.

[0016] The beneficial effects of this invention are as follows: This invention integrates hydrogen energy and green certificate-carbon trading into a low-carbon economic dispatch method for integrated island energy systems. Addressing the challenges of insufficient renewable energy absorption capacity in integrated island energy systems, it combines diversified hydrogen energy utilization with a green certificate-carbon joint trading mechanism and presents a low-carbon economic dispatch strategy for IIES (Integrated Energy Systems). First, it deeply explores the low-carbon potential of hydrogen energy, constructing a synergistic coupling mechanism that integrates hydrogen production through electricity. This mechanism uses green certificates to offset carbon emission reduction costs and provide additional revenue, reducing dependence on fossil fuels. Finally, it establishes an operation and dispatch model aimed at minimizing the overall system operating cost and uses the CPLEX solver to generate a low-carbon economic dispatch scheme for IIES. This invention solves the problems of insufficient renewable energy absorption, high carbon emissions, and high operating costs in integrated island energy systems by integrating diversified hydrogen energy utilization and a green certificate-carbon joint trading mechanism. Attached Figure Description

[0017] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 The flowchart shows the island integrated energy low-carbon economic dispatch method that incorporates hydrogen energy and green certificate-carbon trading in this invention. Figure 2 A framework diagram of an integrated energy system for an island; Figure 3For the green certificate-carbon trading joint mechanism; Figure 4 This refers to the electrical, heating, and cooling load data for MG; Figure 5 Data on contributions to MG New Energy; Figure 6 The result is the power balance optimization result; Figure 7 The result is the result of thermal power balance optimization; Figure 8 The results are for hydrogen power balance optimization. Figure 9 The result is the result of the cold power balance optimization. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0019] I. Integrated Energy Low-Carbon Economic Dispatch Methods for Island Regions like Figure 1 As shown, this embodiment incorporates a comprehensive low-carbon economic dispatch method for island energy that integrates hydrogen energy and green certificate-carbon trading, including the following steps: Step 1: Construct an integrated energy system for the island. For example... Figure 2 As shown, the island integrated energy system of this embodiment includes energy supply equipment, energy storage equipment, and carbon capture device; wherein, the energy supply equipment includes offshore wind turbines, hydrogen electrolysis equipment, methane reactors, hydrogen fuel cells, gas boilers, refrigeration equipment, and seawater desalination devices; the energy storage equipment includes hydrogen storage tanks and hydrogen fuel cells; the carbon capture device is used to capture carbon dioxide and supply it to the methane reactor as a carbon source.

[0020] (1) Hydrogen electrolysis equipment Hydrogen production by electrolysis mainly relies on the electrolysis process to effectively convert electrical energy into hydrogen energy, achieving zero carbon dioxide emissions. The hydrogen electrolysis equipment in this embodiment uses an electrolyzer. Currently, commonly used electrolyzers are divided into alkaline electrolyzers and proton exchange membrane electrolyzers. This embodiment selects the more widely used alkaline electrolyzer. The operating model of the electrolyzer is represented as follows: In the formula: for Hydrogen production capacity of the electrolyzer at any given time; The efficiency of the electrolyzer in converting electrical energy into hydrogen energy is typically set to 85% in this embodiment. for The power consumption of the electrolytic cell at all times; and These represent the maximum and minimum values ​​of the change in power consumption per unit time in the electrolytic cell; and These represent the maximum and minimum power consumption of the electrolytic cell, respectively.

[0021] (2) Methane reactor The main function of a methane reactor is to produce methane from hydrogen. The operating model of a methane reactor is represented as follows: In the formula: for Constantly supplying hydrogen energy to the methane generator; for It continuously outputs the power of natural gas; The conversion efficiency of the methane generator; and These represent the maximum and minimum values ​​of the input hydrogen energy, respectively. The coefficient for calculating CO2; and These represent the maximum and minimum values ​​for the methane generator ramp-up, respectively. For methane generator in The amount of CO2 consumed at any given time.

[0022] (3) Hydrogen fuel cells Hydrogen fuel cells generate electricity and heat by burning hydrogen. This embodiment uses a hydrogen fuel cell with an adjustable thermoelectric ratio. The operating model of the hydrogen fuel cell is represented as follows: In the formula: and They are respectively The output power of the hydrogen fuel cell in terms of electrical and thermal energy at any given time; The input power of hydrogen energy; and These are the electro-thermal conversion efficiencies, respectively. The typical range is 40% to 60%. The typical range is 30% to 50%; and These are the maximum and minimum values ​​of the thermoelectric ratio, respectively. and These represent the maximum and minimum values ​​of the hydrogen energy input power, respectively. and These represent the maximum and minimum values ​​of the change in input hydrogen power per unit time, respectively.

[0023] (4) Gas-fired boiler The operating model of the gas-fired boiler is as follows: In the formula: for The heat output capacity of the gas-fired boiler at all times; The heat production efficiency of a gas-fired boiler; This refers to the gas consumption power of the gas-fired boiler. This refers to the calorific value of natural gas. and These are the maximum and minimum gas consumption power of the gas-fired boiler, respectively. and These represent the maximum and minimum values ​​of the change in gas consumption power per unit time, respectively.

[0024] (5) Refrigeration equipment Refrigeration equipment includes absorption chillers and electric chillers. Absorption chillers convert heat energy into cold energy; while electric chillers convert electrical energy into cold energy. The refrigeration and constraint of refrigeration equipment are represented as follows: In the formula: and They are respectively The cooling capacity and maximum cooling capacity of the constant-time absorption chiller; The refrigeration efficiency of an absorption chiller; and They are respectively The cooling capacity and maximum cooling capacity of the instantaneous refrigerator; This refers to the refrigeration efficiency of the electric chiller.

[0025] (6) Seawater desalination equipment The seawater desalination device in this embodiment uses reverse osmosis for seawater desalination and purification, and its energy consumption is: In the formula: The power consumption of DH; The conversion efficiency of the seawater desalination unit.

[0026] (7) Carbon capture device The energy consumption of a carbon capture device includes stationary energy consumption and operational energy consumption, expressed as follows: In the formula: For carbon capture equipment The electrical power consumed in constantly capturing CO2; and They are respectively Basic and operating energy consumption of real-time carbon capture equipment; The power consumption per unit of CO2 captured; For carbon capture equipment The total amount of CO2 captured at any given time; and They are respectively The amount of CO2 consumed during methanation and the amount of CO2 stored at any given time; for The amount of CO2 emitted by the carbon-producing unit at any given time; The carbon capture rate of the carbon capture equipment.

[0027] (8) Energy storage equipment The microgrid energy storage device in this embodiment includes a hydrogen storage tank and is used in conjunction with a hydrogen fuel cell. The operating constraints of the energy storage device are: In the formula: The energy sources are hydrogen energy and electrical energy; for Storing energy at all times; To maximize energy storage; and They are respectively Constant charging and discharging power; and They are respectively The charging and discharging efficiency of energy storage devices at all times; and These are the charging and discharging state variables, respectively, and are Boolean variables.

[0028] (9) Combined heat and power units The island integrated energy system in this embodiment also includes a combined heat and power (CHP) unit, and the operating model of the CHP unit is as follows: In the formula: The power generation capacity of the combined heat and power (CHP) unit; This refers to the gas consumption of a combined heat and power (CHP) unit. The power generation efficiency of the combined heat and power (CHP) unit; This refers to the calorific value of natural gas.

[0029] As a crucial coupling device between thermal and electrical systems, the combined heat and power (CHP) unit is studied in this embodiment using a common extraction-condensing CHP unit. The CHP unit operates on a "heat-driven power generation" model. Specifically, the electrothermal operating characteristics of the CHP unit are as follows: In the formula: and for The electrical and thermal output power of the cogeneration unit at all times; and for The maximum and minimum values ​​of electrical energy output power at any given time; and for The maximum and minimum values ​​of thermal energy output power at any given time; for The operating status of the cogeneration unit at any time (0 indicates stop, 1 indicates run); , , and This refers to the corresponding electrical energy output of a combined heat and power (CHP) unit under different thermal energy output conditions. , , and This refers to the corresponding heat output of a combined heat and power (CHP) unit under different electrical energy outputs.

[0030] The start-up and shutdown status and ramp-up limits of combined heat and power units are represented as follows: In the formula: for The startup status of the cogeneration unit at any time (0 indicates not started, 1 indicates started). for The current closed state (0 indicates not closed, 1 indicates closed); and These represent the maximum and minimum ramp rates of the combined heat and power (CHP) unit.

[0031] Step 2: Introduce a green certificate-carbon trading joint mechanism, including a carbon trading mechanism and a green certificate mechanism. The green certificate mechanism generates green certificates based on the amount of renewable energy generated, while the carbon trading mechanism uses a tiered carbon trading strategy to calculate carbon trading costs and offsets part of the carbon emissions through green certificates.

[0032] (1) Carbon trading mechanism The carbon trading mechanism is a market-based carbon emission control measure that allows emission entities to buy and sell carbon allowances, provided they comply with total emission controls, by allocating carbon emission allowances through government or regulatory agencies. In my country, the baseline method is typically used to determine the amount of free carbon allowances in an IIES (Environmentally Independent Emission System). Based on this, the carbon allowance constraints for IIES in this embodiment are as follows: In the formula: Carbon quotas for combined heat and power units; For the entire scheduling cycle; and These are the benchmarks for carbon emission allocation per unit of electricity and per unit of heat, respectively. Carbon quotas for gas-fired boilers; This refers to the output thermal power of the gas-fired boiler. The total carbon allowance for the island's integrated energy system.

[0033] The actual carbon emissions model of IIES can be expressed as: In the formula: For IIES The power generated by the combined heat and power unit and the gas-fired boiler Emissions; , These are the carbon emission coefficients per unit of electricity and per unit of heat, respectively. This represents the total carbon emissions of IIES.

[0034] carbon emission rights It can be calculated using the following formula: Carbon trading costs are calculated using a tiered system: In the formula: Carbon trading costs for island integrated energy systems; This serves as the base price for carbon trading; The percentage increase in transaction price; The interval length; For carbon emission rights.

[0035] (2) Green Certificate Mechanism The green certificate mechanism is a certification system established in my country to promote renewable energy generation and the use of green electricity. This mechanism, combined with the renewable energy quota system, requires users to include a certain proportion of renewable energy in their electricity consumption to promote green electricity consumption. When the number of green certificates held by the system is insufficient to meet the quota, it must be purchased to make up the difference; excess green certificates can be sold for profit. The constraints on the number of green certificates held by microgrids are as follows: In the formula: The green certificate quota required for microgrids; This refers to the green certificate quantity quota coefficient; The number of green certificates obtained for microgrid renewable energy power generation; The conversion coefficient between new energy power generation and the number of green certificates is given, with each green certificate corresponding to 1 MW·h of grid-connected wind power. for At all times, the new energy source outputs electrical power; The amount of green certificates that can be used for green certificate trading.

[0036] In the initial stages of green certificate trading, the government grants the market pricing power, allowing both parties to negotiate prices. As the correlation between green certificates and carbon trading gradually strengthens, price fluctuations in the carbon market may directly affect green certificate prices. Therefore, inspired by the tiered carbon trading model, this embodiment designs a tiered green certificate trading method. The base price of each green certificate is 50 yuan, and the cost of green certificates is calculated using a tiered method: In the formula: The cost of green certificates borne by the island's integrated energy system; The base price for green certificate trading; The percentage increase in transaction price; The interval length; The amount of green certificates that can be used for green certificate trading.

[0037] (3) Green Certificate-Carbon Trading Joint Mechanism Figure 3 The GET-CET mechanism's operational framework was demonstrated. The core of this coordination mechanism lies in fully exploring and utilizing the carbon emission reduction attributes of green certificates, achieving an organic connection between two environmental rights markets through scientific quantification methods and clear rights allocation rules. Specifically, after clearly defining and allocating green certificate rights, energy system operators calculate the corresponding carbon emission reductions based on the number of green certificates they hold using standardized accounting methods. These certified carbon emission reductions are then incorporated into the carbon emission accounting system, directly offsetting a portion of the carbon emissions generated during system operation, thereby influencing quota demand and trading strategies in the carbon trading market.

[0038] Given that my country's energy supply is primarily based on coal-fired power generation, the carbon emission reduction corresponding to green certificates is often quantified by comparing the carbon emission intensity differences between renewable energy power generation and coal-fired power generation. The specific calculation is as follows: In the formula: The amount of carbon emissions that can be offset by green certificates; , These represent the carbon emissions from new energy power generation and traditional coal-fired power generation during the dispatch cycle, respectively.

[0039] In the green certificate-carbon trading joint mechanism, the total carbon emissions of the island integrated energy system are: in: For carbon emission rights; The total carbon emissions of the island's integrated energy system; The amount of carbon emissions that can be offset by green certificates; The green certificate quota required for microgrids; The total carbon allowance for the island's integrated energy system; the carbon trading cost after offsetting carbon emissions with new energy sources based on carbon trading costs and green certificate costs.

[0040] Step 3: To minimize the overall operating cost of the island's integrated energy system, an optimized scheduling model is established. The operating cost includes natural gas purchase cost, carbon trading cost, green certificate cost, wind curtailment penalty cost, carbon storage cost, and demand response compensation cost.

[0041] This embodiment aims to minimize the overall operating cost of the system. It constructs an IIES optimization model that integrates hydrogen energy and the GCT-CET mechanism. This model deeply explores the low-carbon potential of hydrogen energy and, combined with the GCT-CET mechanism, uses green certificates to offset carbon emission reduction costs and provide additional benefits, thereby optimizing the output of each device within the system.

[0042] (1) Objective function The operating costs of IIES include the cost of purchasing natural gas. Carbon trading costs Green certificate costs Wind curtailment penalty costs Carbon sequestration costs Demand response compensation costs Specifically, the objective function for optimizing the scheduling model is: in: in: Cost of purchasing natural gas; The cost of curtailing wind power; For carbon trading costs; Cost of carbon sequestration; Cost of green certificates; To compensate for costs in response to demand; The price at which gas is purchased from the natural gas network; for Real-time gas purchase capacity; The penalty cost per unit of energy curtailment; and They are respectively Unabsorbed wind and solar power; Unit cost of carbon sequestration; for Carbon emissions at any given time; , and Compensation coefficients for unit transferred electrical load and unit power cut-off and heat load, respectively; For transferable electrical loads; and These respectively indicate that the electrical and thermal loads can be reduced.

[0043] As can be seen from the above operating costs, the IIES constructed in this embodiment has achieved full-chain coupled modeling of source-load-storage-trading by introducing strategies such as green certificate trading, tiered carbon trading, multi-stage utilization of hydrogen energy, carbon capture and storage, and comprehensive demand response.

[0044] (2) Constraints In this embodiment, the constraints of the optimized scheduling model include constraints on energy interaction with the external environment, power balance constraints, carbon quota constraints, constraints on the number of green certificates held by the microgrid, and constraints on the comprehensive demand response of electricity and heat.

[0045] (1) Energy interaction constraints with the outside world The energy interaction constraint with the external environment is represented as: In the formula: and They are respectively The amount of gas to be purchased from the outside world at all times, and its upper limit.

[0046] (2) Power balance constraint The power balance constraint is: In the formula: for New energy sources are always contributing their power; , as well as , They are respectively The charging and discharging power of hydrogen storage tanks and electrical energy storage at all times; for The cold load at any time.

[0047] (3) Carbon quota constraints Carbon quota constraints are: In the formula: Carbon quotas for combined heat and power units; For the entire scheduling cycle; and These are the benchmarks for carbon emission allocation per unit of electricity and per unit of heat, respectively. Carbon quotas for gas-fired boilers; This refers to the output thermal power of the gas-fired boiler. The total carbon allowance for the island's integrated energy system.

[0048] (4) Constraints on the number of green certificates held by microgrids The number of green certificates that microgrids can hold is subject to the following constraints: In the formula: The green certificate quota required for microgrids; This refers to the green certificate quantity quota coefficient; The number of green certificates obtained for microgrid renewable energy power generation; The conversion coefficient between new energy power generation and the number of green certificates is given, with each green certificate corresponding to 1 MW·h of grid-connected wind power. for At all times, the new energy source outputs electrical power; The amount of green certificates that can be used for green certificate trading.

[0049] (5) Constraints on the overall demand response of electricity and heat The overall demand response constraint for electric heating is: In the formula: and These are the original electrical and thermal loads, respectively; and These are the electrical and thermal loads following the demand response; and These respectively indicate that the electrical and thermal loads can be reduced; For transferable electrical loads; and These can reduce the electrical and thermal load coefficients, respectively. This is the transferable electrical load factor.

[0050] Step 4: Solve the optimized scheduling model using a solver to generate a low-carbon economic scheduling scheme and optimize the output of each device and the charging and discharging strategies of energy storage. In this embodiment, the solver is the CPLEX solver, and the model solution is implemented based on the MATLAB platform.

[0051] II. Case Analysis This embodiment uses a certain IIES in Guangdong as an example to verify the effectiveness of the constructed system and model. One scheduling cycle is 24 hours, and the unit step time is 1 hour. The system's load curve and the predicted power output of new energy sources are shown below. Figure 4-5 The operating parameters are shown in Table 1, and the relevant parameters of the GCT-CET mechanism are shown in Table 2. The gas sales price on the natural gas network... Take 0.45 yuan / m 3 This embodiment uses the CPLEX solver to solve the constructed model, and the generated economic operation scheduling strategy is as follows: Figure 6-9 As shown.

[0052] Figure 6 The demonstration showcased the power output of IIES's energy supply equipment, power consumption of energy-consuming equipment, and electrical load. During the daytime, when renewable energy output is sufficient, the system prioritizes the use of renewable energy for power generation and drives the electrolyzer for hydrogen production and energy storage equipment charging, fully utilizing excess renewable energy. During peak load periods, gas turbines and hydrogen fuel cells flexibly supplement power supply, and energy storage equipment discharges as needed to reduce peak load, effectively alleviating power supply pressure. The carbon capture system operates synchronously during peak electricity consumption periods. Although this increases power consumption, it partially offsets carbon emission costs, verifying the synergistic scheduling effect of the proposed multi-energy complementarity and carbon trading mechanism.

[0053] Figure 7 The diagram illustrates the scheduling effect of IIES thermal power. As shown, the gas turbine serves as the primary heat source, generating heat and electricity simultaneously. The gas boiler, as an auxiliary heat source, is flexibly activated during peak heat load periods to ensure a balanced heat supply. The hydrogen fuel cell provides some heat while generating electricity, further improving overall energy efficiency. The absorption chiller consumes excess heat energy for cooling, achieving combined heat, power, and cooling coupling, avoiding heat waste, and effectively improving heat utilization and the overall economic efficiency of the system.

[0054] Figure 8 The results of hydrogen energy balance optimization are presented. (By...) Figure 6 It is evident that the electrolyzer efficiently produces hydrogen during periods of surplus renewable energy generation, converting electrical energy into hydrogen for storage, thus ensuring the supply of electricity and natural gas for subsequent periods. The methane generator flexibly consumes hydrogen to produce methane, alleviating dependence on natural gas, while the fuel cell generates electricity using hydrogen during peak load periods, playing a role in peak shaving and valley filling. The hydrogen storage equipment enables cross-period regulation of hydrogen energy, improving the utilization level of renewable energy and the system's low-carbon flexibility.

[0055] Figure 9 The results of IIES cold power balance optimization are presented. (By...) Figure 7 As can be seen, the system employs a combination of electric chillers and absorption chillers for cooling, achieving a stable supply of cooling load and efficient energy utilization. The electric chillers operate first when electricity prices are low or renewable energy sources are abundant, making full use of electrical resources; the absorption chillers utilize waste heat from the system for cooling, improving the cascade utilization rate of thermal energy. During peak cooling load periods, the two cooling methods operate in tandem, effectively meeting residents' cooling needs while alleviating peak grid pressure, demonstrating the comprehensive benefits of combined cooling, heating, and power (CCHP).

[0056] In summary, the IIES constructed in this embodiment, which integrates hydrogen energy utilization in multiple stages and the GET-CET mechanism, can realize the multi-stage utilization of hydrogen energy and effectively reduce carbon emissions and improve the renewable energy absorption rate through the GET-CET mechanism.

[0057] III. Summary In summary, this embodiment addresses the practical needs of IIES in renewable energy consumption, economic operation, and low-carbon development by constructing an IIES that integrates diversified hydrogen energy utilization and the GET-CET mechanism. It encompasses equipment models covering multiple stages, including hydrogen production from electricity, hydrogen-to-methane production, hydrogen storage, and fuel cells, and introduces a coupling mechanism of tiered carbon trading and green certificate deduction, establishing an optimal scheduling model aimed at minimizing the overall system operating cost. The CPLEX solver is used to solve this model, generating a low-carbon economic scheduling scheme for the IIES. Experimental results show that the proposed model can effectively improve the renewable energy consumption level of the IIES, reduce overall operating costs and carbon emissions, and verify the feasibility and effectiveness of diversified hydrogen energy utilization and the GET-CET mechanism in improving the system's economic and environmental performance. However, this embodiment does not further consider the uncertainties of new energy output and load demand, as well as the dynamic impact of different carbon allowances and green certificate price fluctuations on the system's economics. To address these shortcomings, future research can combine interval and distributed optimization methods, introduce real market mechanisms and price feedback, and further enhance the adaptability and promotion value of the proposed model in practical engineering.

[0058] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A method for integrated low-carbon economic dispatch of island energy combining hydrogen energy and green certificate-carbon trading, characterized in that: Includes the following steps: Step 1: Construct an integrated island energy system, including energy supply equipment, energy storage equipment, and carbon capture devices; wherein, the energy supply equipment includes offshore wind turbines, hydrogen electrolysis equipment, methane reactors, hydrogen fuel cells, gas boilers, refrigeration equipment, and seawater desalination devices; the energy storage equipment includes hydrogen storage tanks and hydrogen fuel cells; the carbon capture device is used to capture carbon dioxide and supply it to the methane reactor as a carbon source; Step 2: Introduce a green certificate-carbon trading joint mechanism, including a carbon trading mechanism and a green certificate mechanism; the green certificate mechanism generates green certificates based on new energy power generation, and the carbon trading mechanism uses a tiered carbon trading strategy to calculate carbon trading costs and offsets part of the carbon emissions through green certificates; Step 3: To minimize the overall operating cost of the island's integrated energy system, an optimized scheduling model is established. The operating cost includes natural gas purchase cost, carbon trading cost, green certificate cost, wind curtailment penalty cost, carbon storage cost, and demand response compensation cost. Step 4: Use the solver to solve the optimized scheduling model, generate a low-carbon economic scheduling scheme, and optimize the output of each device and the charging and discharging strategy of energy storage.

2. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 1, characterized in that: The hydrogen electrolysis equipment uses an electrolyzer, and the operating model of the electrolyzer is represented as follows: In the formula: for Hydrogen production capacity of the electrolyzer at any given time; The efficiency of an electrolyzer in converting electrical energy into hydrogen energy; for The power consumption of the electrolytic cell at all times; and These represent the maximum and minimum values ​​of the change in power consumption per unit time in the electrolytic cell; and These represent the maximum and minimum power consumption of the electrolytic cell, respectively. The operating model of the methane reactor is represented as follows: In the formula: for Constantly supplying hydrogen energy to the methane generator; for It continuously outputs the power of natural gas; The conversion efficiency of the methane generator; and These represent the maximum and minimum values ​​of the input hydrogen energy, respectively. The coefficient for calculating CO2; and These represent the maximum and minimum values ​​for the methane generator ramp-up, respectively. For methane generator in The amount of CO2 consumed at any given time; The operating model of the hydrogen fuel cell is represented as follows: In the formula: and They are respectively The output power of the hydrogen fuel cell in terms of electrical and thermal energy at any given time; This refers to the input power of hydrogen energy; and These are the electrical and thermal conversion efficiencies, respectively. and These are the maximum and minimum values ​​of the thermoelectric ratio, respectively. and These represent the maximum and minimum values ​​of the hydrogen energy input power, respectively. and These represent the maximum and minimum values ​​of the change in input hydrogen power per unit time; The operating model of the gas-fired boiler is as follows: In the formula: for The heat output capacity of the gas-fired boiler at all times; The heat production efficiency of a gas-fired boiler; This refers to the gas consumption power of the gas-fired boiler. This refers to the calorific value of natural gas. and These are the maximum and minimum gas consumption power of the gas-fired boiler, respectively. and These represent the maximum and minimum values ​​of the change in gas consumption power per unit time, respectively. The refrigeration equipment includes an absorption chiller and an electric chiller, and the refrigeration and constraint of the refrigeration equipment are represented as follows: In the formula: and They are respectively The cooling capacity and maximum cooling capacity of the constant-time absorption chiller; The refrigeration efficiency of an absorption chiller; and They are respectively The cooling capacity and maximum cooling capacity of the instantaneous refrigerator; The refrigeration efficiency of the electric chiller; The seawater desalination device uses reverse osmosis for seawater desalination and purification, and its energy consumption is: In the formula: The power consumption of DH; The conversion efficiency of the seawater desalination unit; The energy consumption of the carbon capture device includes stationary energy consumption and operational energy consumption, expressed as follows: In the formula: For carbon capture equipment The electrical power consumed in constantly capturing CO2; and They are respectively Basic and operating energy consumption of real-time carbon capture equipment; The power consumption per unit of CO2 captured; For carbon capture equipment The total amount of CO2 captured at any given time; and They are respectively The amount of CO2 consumed during methanation and the amount of CO2 stored at any given time; for The amount of CO2 emitted by the carbon-producing unit at any given time; The carbon capture rate of the carbon capture equipment; The operating constraints of the energy storage device are as follows: In the formula: The energy sources are hydrogen energy and electrical energy; for Storing energy at all times; To maximize energy storage; and They are respectively Constant charging and discharging power; and They are respectively The charging and discharging efficiency of energy storage devices at all times; and These are the charging and discharging state variables, respectively, and are Boolean variables.

3. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 1, characterized in that: The island integrated energy system also includes a combined heat and power (CHP) unit, the operating model of which is as follows: In the formula: The power generation capacity of the combined heat and power (CHP) unit; This refers to the gas consumption of a combined heat and power (CHP) unit. The power generation efficiency of the combined heat and power (CHP) unit; This refers to the calorific value of natural gas. The electrothermal operating characteristics of the combined heat and power unit are as follows: In the formula: and for The electrical and thermal output power of the cogeneration unit at all times; and for The maximum and minimum values ​​of electrical energy output power at any given time; and for The maximum and minimum values ​​of thermal energy output power at any given time; for The operating status of the cogeneration unit at all times; , , and This refers to the corresponding electrical energy output of a combined heat and power (CHP) unit under different thermal energy output conditions. , , and This refers to the corresponding heat output of a combined heat and power unit under different electrical energy outputs. The start-up and shutdown status and ramp-up limits of the combined heat and power unit are represented as follows: In the formula: for The startup status of the cogeneration unit at all times; for The state of being constantly off; and These represent the maximum and minimum ramp rates of the combined heat and power (CHP) unit.

4. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 1, characterized in that: In the aforementioned green certificate-carbon trading joint mechanism, the total carbon emissions of the island integrated energy system are: in: For carbon emission rights; The total carbon emissions of the island's integrated energy system; The amount of carbon emissions that can be offset by green certificates; The green certificate quota required for microgrids; The total carbon allowance for the island's integrated energy system; the carbon trading cost after offsetting carbon emissions with new energy sources, based on carbon trading costs and green certificate costs, and: Carbon trading costs are calculated using a tiered system: In the formula: Carbon trading costs for island integrated energy systems; This serves as the base price for carbon trading; The percentage increase in transaction price; The interval length; For carbon emission rights; The cost of green certificates is calculated using a tiered approach: In the formula: The cost of green certificates borne by the island's integrated energy system; The base price for green certificate trading; The percentage increase in transaction price; The interval length; The amount of green certificates that can be used for green certificate trading.

5. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in any one of claims 1-4, characterized in that: The objective function of the optimized scheduling model is: in: in: Cost of purchasing natural gas; The cost of curtailing wind power; For carbon trading costs; Cost of carbon sequestration; Cost of green certificates; To compensate for costs in response to demand; The price at which gas is purchased from the natural gas network; for Real-time gas purchase capacity; The cost of energy curtailment per unit; and They are respectively Unabsorbed wind and solar power; Unit cost of carbon sequestration; for Carbon emissions at any given time; , and Compensation coefficients for unit transferred electrical load and unit power cut-off and heat load, respectively; For transferable electrical loads; and These respectively indicate that the electrical and thermal loads can be reduced; The constraints of the optimized scheduling model include constraints on energy interaction with the external environment, power balance constraints, carbon quota constraints, constraints on the number of green certificates held by microgrids, and constraints on the comprehensive demand response of electricity and heat.

6. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 5, characterized in that: The constraint on energy interaction with the external environment is expressed as follows: In the formula: and They are respectively The amount of gas to be purchased from the outside world at all times, and its upper limit.

7. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 5, characterized in that: The power balance constraint is: In the formula: for New energy sources are always contributing their power; , as well as , They are respectively The charging and discharging power of hydrogen storage tanks and electrical energy storage at all times; for The cold load at any time.

8. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 5, characterized in that: The carbon quota constraint is as follows: In the formula: Carbon quotas for combined heat and power units; For the entire scheduling cycle; and These are the benchmarks for carbon emission allocation per unit of electricity and per unit of heat, respectively. Carbon quotas for gas-fired boilers; This refers to the output thermal power of the gas-fired boiler. The total carbon allowance for the island's integrated energy system; The constraint on the number of green certificates held by the microgrid is as follows: In the formula: The green certificate quota required for microgrids; This refers to the green certificate quantity quota coefficient; The number of green certificates obtained for microgrid renewable energy power generation; This is the conversion coefficient between new energy power generation and the number of green certificates; for At all times, the new energy source outputs electrical power; The amount of green certificates that can be used for green certificate trading.

9. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 7, characterized in that: The comprehensive demand response constraint for electrothermal energy is: In the formula: and These are the original electrical and thermal loads, respectively; and These are the electrical and thermal loads following the demand response; and These respectively indicate that the electrical and thermal loads can be reduced; For transferable electrical loads; and These can reduce the electrical and thermal load coefficients, respectively. This is the transferable electrical load factor.

10. The island integrated energy low-carbon economic dispatch method incorporating hydrogen energy and green certificate-carbon trading as described in claim 1, characterized in that: The solver is the CPLEX solver, and the model is solved based on the MATLAB platform.

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