A method for optimizing operation of an integrated energy system considering power market transactions

Abstract

The application discloses a kind of integrated energy system optimization operation method considering electric power market transaction.The application method comprehensively considers green certificate-carbon trading interactive mechanism, detailed P2G segmented operation and heat-power ratio adjustable technology, constructs the optimization operation target with minimum purchase energy cost, carbon trading cost, green certificate trading cost, energy abandonment cost, segmented processing to traditional electric-gas system, detailed green hydrogen produced in utilization process, secondly research heat-power ratio adjustable technology of combined heat and power and hydrogen fuel cell equipment, improve system flexibility, reduce energy abandonment cost;Finally, introduce green certificate-carbon trading interactive mechanism, establish the linkage between carbon emission trading and green certificate trading, in the form of marketization, improve new energy consumption rate and renewable energy utilization rate.

Description

Technical Field

[0001] This invention belongs to the field of integrated energy system optimization and scheduling, and proposes an optimized operation model for green hydrogen systems that comprehensively considers the green certificate-carbon trading interaction mechanism, refined P2G segmented operation, and adjustable heat-to-power ratio technology. Background Technology

[0002] With the growth of global energy demand and the increasing prominence of environmental issues, the supply of traditional fossil fuels faces numerous challenges. Therefore, my country is actively promoting the development and utilization of renewable energy, increasing the proportion of renewable energy power, and reducing the consumption of traditional fossil fuels. The power-to-gas (P2G) integrated energy system establishes a multi-energy complementary architecture encompassing cooling, heating, power generation, and gas supply, which can provide diverse energy needs for users within the system. However, its operation involves the production and utilization of multiple energy sources, which can easily lead to energy cascade losses and low utilization rates. Furthermore, the diversity of energy demands places high demands on the flexible absorption capacity of the P2G system.

[0003] To encourage proactive energy conservation and emission reduction within the system and to advance the marketization of renewable energy, it is necessary to implement carbon trading (CET) and green certificate trade (GCT) mechanisms. Currently, my country's exploration of the green certificate and carbon trading markets is still in its initial stages. The supply and demand relationship among market participants is difficult to balance, and the flexibility of GCT cooperation with other electricity markets is limited. Summary of the Invention

[0004] In summary, existing technologies for promoting wind power consumption using P2G have neglected the potential benefits of segmented production, resulting in significant energy cascade losses. They also rarely consider the advantages of adjustable heat-to-power ratio (HE / G ratio) technology in combined heat and power (CHP) systems. Furthermore, the interaction mechanism between green certificate trading and carbon trading urgently needs further research. To address the shortcomings of existing methods, this invention comprehensively considers the green certificate-carbon trading interaction mechanism, segmented P2G operation, and adjustable HE / G ratio technology. It constructs an optimized operation objective that minimizes energy purchase costs, carbon trading costs, green certificate trading costs, and curtailment costs. This invention proposes a comprehensive energy system green certificate-carbon trading interaction optimization method that considers adjustable HE / G ratio and segmented P2G operation. This method segments the traditional power-to-gas system, refining the utilization of green hydrogen generated during the process. Secondly, it studies the adjustable HE / G ratio technology of CHP and hydrogen fuel cell equipment to improve system flexibility and reduce curtailment costs. Finally, it introduces a green certificate-carbon trading interaction mechanism to establish a linkage between carbon emission trading and green certificate trading, thereby increasing the renewable energy consumption rate and utilization rate through market mechanisms.

[0005] To achieve the above-mentioned objectives, a method for optimizing the operation of a comprehensive energy system that considers electricity market transactions includes the following steps:

[0006] Step 1: Construct a segmented and refined P2G runtime architecture.

[0007] Step 2: Establish a combined heat and power (CHP) unit model based on adjustable heat and power ratio. On the basis of the coordinated operation of gas-fired CHP and hydrogen fuel cell (HFC) equipment, introduce adjustable heat and power ratio technology. Considering the P2G segmented refined operation architecture in Step 1, comprehensively construct an IES optimized operation model for electro-hydrogen production. This model enables the IES to adapt to the electric and heat load demand in different time periods and flexibly adjust the output strategy according to time-of-use electricity prices, thereby improving the economic efficiency of system operation.

[0008] Step 3: Construct a joint trading market framework for carbon trading (CET) and green certificate trading (GCT) based on the green certificate-carbon trading interaction mechanism.

[0009] Step 4: Based on the established joint trading market framework of carbon trading (CET) and green certificate trading (GCT) and the IES optimized operation model of hydrogen production from electricity, construct an objective function that minimizes the total operating cost. Taking into account renewable energy output constraints, grid power interaction constraints, energy storage constraints, equipment operation constraints, power balance constraints, and market trading constraints, construct a comprehensive energy system optimized operation model with embedded adjustable heat-to-power ratio and P2G segmented operation constraints under the carbon-green certificate trading mechanism. Solve the comprehensive energy system optimized operation model to achieve green certificate-carbon trading interaction optimization.

[0010] Furthermore, the specific method for step 1 is as follows:

[0011] The conventional power-to-gas (P2G) process is refined into two stages by combining a hydrogen fuel cell (HFC), an electrolyzer (EL), and a methane reactor (MR). In the first stage, the input electrical energy is converted into hydrogen energy via the EL, and the CO2 generated in the system is collected and stored by a CO2 collection device. In the second stage, a portion of the hydrogen energy is used as an intermediate input in the P2G process to synthesize natural gas with CO2 in the MR, while another portion is directly converted into electricity and heat energy by the HFC. The remaining hydrogen energy is stored in a hydrogen storage tank. The above equipment model is described as follows:

[0012] 1) EL device model:

[0013]

[0014] In the formula: P e,EL (t) represents the electrical energy input to EL during time period t; η is the hydrogen energy output by EL during time period t; EL The energy conversion efficiency of EL; These are the upper and lower limits of the electrical energy input to EL, respectively; These represent the upper and lower limits of EL's ramp rate, respectively.

[0015] 2) MR equipment model:

[0016]

[0017] In the formula: The hydrogen energy input to MR during time period t; P MR,g (t) represents the natural gas power output by MR during time period t; η MR The energy conversion efficiency of MR; These are the upper and lower limits of hydrogen energy input to MR, respectively; These represent the upper and lower limits of MR's ramp rate, respectively.

[0018] Furthermore, the specific method for step two is as follows:

[0019] The principle behind adjustable heat-to-power ratio (CHP) technology is as follows: by controlling the air intake of the generator set, the power generation is adjusted in real time. Simultaneously, the supplementary combustion boiler adjusts the heat supply by controlling the supplementary combustion amount; thus, the CHP system can be flexibly adjusted according to actual needs to maximize energy efficiency. Its working model is as follows:

[0020]

[0021] In the formula: P g,CHP (t) represents the natural gas power input to CHP during time period t; P CHP,e (t), P CHP,h (t) represents the electrical and thermal power output of CHP during time period t; These represent the efficiency of converting natural gas into electricity and heat, respectively. These are the upper and lower limits of the natural gas power input to CHP, respectively; These are the upper and lower limits of CHP power ramp-up, respectively. These are the upper and lower limits of the thermoelectric ratio of CHP, respectively.

[0022] Similarly, HFCs burn hydrogen for both power and heat supply. By changing the flow rate of the cooling circulating water, the heat-to-power ratio can be adjusted according to the real-time electrothermal load. The working model is as follows:

[0023]

[0024] In the formula: P represents the hydrogen power input to the HFC during time period t; HFC,e (t), P HFC,h (t) represents the electrical and thermal power output of the HFC during time period t; η HFC,e η HFC,h These represent the efficiencies of HFC in converting energy into electricity and heat, respectively. These are the upper and lower limits of hydrogen energy input to HFCs, respectively. These represent the upper and lower limits of HFC ramp rate; These represent the upper and lower limits of the thermoelectric ratio of HFC.

[0025] The model established above is embedded into the P2G segmented refined operation model in step one to obtain the IES optimized operation model for electro-hydrogen production.

[0026] Furthermore, the specific method for step three is as follows:

[0027] 1) GCT Mechanism. GCT can be used to verify and track the generation and source of renewable energy. The GCT mechanism converts the actual consumption of renewable energy generation into green certificates (referred to as green certificates). Renewable energy consumption quotas are determined by relevant regulatory authorities. Companies that fail to meet their quotas need to purchase green certificates from the market to meet their targets. Conversely, they can convert their renewable energy generation into green certificates for sale. This constrains the consumption of renewable energy by IES (Environmental Engineering Systems). The calculation method for green certificate transaction costs is as follows:

[0028]

[0029] In the formula: C GCT λ represents the transaction cost of green certificates; ρ represents the unit price of green certificate transactions; ρ represents the green certificate quota coefficient that IES needs to hold; δ represents the quantification coefficient for converting renewable energy generation into green certificates; P PV (t), P WT (t) represents the output power of distributed photovoltaic and wind power at time t, respectively; P e,Load (t) represents the electrical load at time t; P HFC,e (t) represents the electrical power generated by the hydrogen consumption of the HFC device at time t.

[0030] 2) CET Mechanism. The carbon trading mechanism is a market mechanism based on carbon emission rights. Producers formulate reasonable production plans based on carbon allowances issued by regulatory authorities. When actual carbon emissions exceed the available carbon emission allowances, they must purchase carbon emission rights in the carbon trading market; conversely, they can sell the remaining carbon emission allowances on the market. The calculation process for carbon emission costs can be expressed as follows:

[0031]

[0032] In the formula: C CET σ represents the carbon emission trading cost; k represents the unit carbon trading price; γ represents the tier length; and γ represents the unit price growth rate. st This refers to the carbon emissions trading volume.

[0033] The integrated energy system purchases electricity from its parent system via thermal power generation. Following the baseline method, the energy system's electricity purchases, CHP (Consumer Health Product), and GB (Gross National Standard) are the three sources of carbon emissions. Therefore, the specific carbon emissions can be expressed as:

[0034]

[0035] In the formula: P e,buy (t) represents the amount of electricity the system purchases from the grid during time period t; B stg For the carbon emissions generated; B s β1 represents the carbon emissions allocated per unit of power; β2 represents the carbon emissions allocated per unit of power; B MR ω represents the actual amount of CO2 absorbed by MR; ω is the CO2 absorption coefficient during the MR hydrogen-to-natural gas conversion process.

[0036] 3) GCT-CET Interaction Mechanism. Information on renewable energy generation and consumption within the system can be obtained through green certificate trading. Therefore, by comparing the carbon emissions of renewable energy and traditional thermal power generation, the carbon emission reduction of green electricity used by enterprises compared to traditional electricity can be calculated. The established green certificate-carbon trading interaction mechanism allows IES (Engineering, Procurement, and Construction) companies to partially convert green certificates into carbon emission allowances. The specific calculation method for this conversion is as follows:

[0037]

[0038] In the formula: B green Carbon emission allowances obtained by converting renewable energy power generation into green certificates; κ is the conversion coefficient.

[0039] In the normal trading mode of the green certificate market and the carbon trading market, the GCT-CET interaction mechanism forms a link between the two markets, thereby constructing a joint trading market framework for carbon trading (CET) and green certificate trading (GCT).

[0040] Furthermore, the specific method for step four is as follows:

[0041] An integrated energy system optimization operation model is constructed under the carbon-green certificate trading mechanism, which incorporates adjustable heat-to-power ratio and P2G segmented operation constraints. The model consists of two parts: objective function and operation constraints.

[0042] Based on the aforementioned CET and GCT joint trading market framework, carbon trading costs and green certificate trading costs are obtained; based on the IES optimized operation model for hydrogen production via electricity, the energy purchase cost and curtailment cost of the IES are obtained. Taking into account the energy purchase cost of the IES... Cost of curtailment Carbon trading cost C CET Transaction costs of green certificates C GCT The objective function that minimizes the total operating cost F is constructed as follows:

[0043]

[0044] in:

[0045] Energy purchase cost for:

[0046]

[0047] In the formula: Let t be the interaction price between the power grid and the upstream power grid. Let P be the price of gas purchased from the upstream gas network at time t. g,buy (t) represents the amount of gas purchased from the upper-level gas network during time period t.

[0048] Cost of curtailment for

[0049]

[0050] Where: δ WT The cost of wind curtailment penalty per unit; P WT,cut (t) represents the wind curtailment power during time period t; δ PV The cost of per unit of abandoned light penalty; P PV,cut (t) represents the abandoned light power during time period t.

[0051] By establishing various operational constraints as boundary conditions for solving the objective function, the proposed constraints include:

[0052] 1) Renewable energy output constraints:

[0053]

[0054] In the formula: P WT (t) represents the wind power output during time period t; P represents the upper limit of wind power output. PV (t) represents the photovoltaic output power during time period t; This represents the upper limit of photovoltaic output power.

[0055] 2) Power constraints between power grids:

[0056]

[0057] In the formula: P grid (t) represents the power exchanged with the upstream power grid at time t. Let t be the maximum power exchanged with the upstream power grid.

[0058] 3) Energy storage operation constraints:

[0059] Since the models of electric, thermal, gas, and hydrogen energy storage devices are similar, a unified model is used to model the constraints of energy storage devices.

[0060]

[0061] In the formula: These represent the charging and discharging power of the nth type of energy storage device during time period t; Let the maximum power of the nth type of energy storage device during a single charge and discharge cycle be denoted as . All are binary variables, representing the charging and discharging state parameters of the nth type of energy storage device during time period t, P ES,n (t) represents the final output power of the nth type of energy storage device; These are the charging and discharging efficiencies of the nth type of energy storage device, respectively; S n (t) represents the real-time capacity of the nth type of energy storage device during time period t; Let n be the rated capacity of the nth type of energy storage device; These represent the upper and lower limits of the capacity of the nth type of energy storage device, respectively.

[0062] 4) Energy purchase constraints:

[0063]

[0064] In the formula: These are the limits for purchasing gas and electricity for different time periods.

[0065] 5) Power balance constraints:

[0066] P e,buy (t)=P e,Load (t)+P e,EL (t)+P ES,e (t)-P WT (t)-P HFC,e (t) (16)

[0067] In the formula: P ES,e (t) represents the power input to the energy storage device during time period t.

[0068] 6) Gas power balance constraint:

[0069] P g,buy (t)=P g,Load (t)+P ES,g (t)+P g,CHP (t)+P g,GB (t)+P MR,g (t) (17)

[0070] In the formula: P g,Load (t) represents the gas load during time period t; P ES,g (t) represents the power input to the energy storage device during time period t.

[0071] 7) Thermal power balance constraint:

[0072] P HFC,h (t)+P CHP,h (t)+P GB,h (t)=P h,Load (t)+P ES,h (t)(18)

[0073] In the formula: P h,Load (t) represents the heat load during time period t; P ES,h (t) represents the power input to the thermal storage device during time period t.

[0074] 8) Hydrogen balance constraint:

[0075]

[0076] In the formula: The power input to the hydrogen storage device during time period t.

[0077] 9) Carbon market constraints:

[0078]

[0079] In the formula: C CET,i and C CET,o These represent the total amount of carbon emission rights that IES purchases and sells to external carbon markets, respectively. and These represent the existing stock and the upper limit of carbon emission rights in the market, respectively.

[0080] 10) Constraints in the green certificate market:

[0081]

[0082] In the formula: C GCT,i and C GCT,o These represent the number of green certificates that IES buys and sells to the green certificate market, respectively. and These represent the existing stock and the maximum shortfall of green certificates in the market, respectively; B tra The number of green certificates converted into carbon allowances; B GCT This represents the number of green certificates traded in the market.

[0083] The YALMIP toolbox and CPLEX solver were used on the MATLAB software platform to solve the integrated energy system optimization operation model.

[0084] The beneficial effects of this invention are as follows:

[0085] By utilizing a segmented and refined P2G operating architecture to reduce hydrogen energy cascade losses, and through combined heat and power generation with adjustable cooling circulating water flow rate and adjustable heat-to-power ratio technology for hydrogen fuel cell equipment, the IES (Environmental Engineering System) can adapt to changes in electrical and thermal load demand at different times. Secondly, the green certificate-carbon trading interaction mechanism improves the absorption capacity of renewable energy while constraining the system's carbon emissions. The conversion mechanism between green certificates and carbon emission rights increases investment flexibility between the two markets, incentivizes the production and absorption of clean energy, thereby achieving more efficient resource allocation and more comprehensive environmental benefits. Attached Figure Description

[0086] Figure 1 A chart showing time-of-use electricity and gas prices;

[0087] Figure 2 Forecast output and load curves for renewable energy sources;

[0088] Figure 3 This is a system structure block diagram according to an embodiment of the present invention;

[0089] Figure 4 This is a diagram illustrating the operational framework of the green certificate-carbon trading interaction mechanism according to an embodiment of the present invention.

[0090] Figure 5 Thermoelectric ratio curves of HFC and CHP;

[0091] Figure 6 This is an energy flow diagram. Detailed Implementation

[0092] The following describes an optimized operation method for a comprehensive energy system considering electricity market transactions, established by the present invention with reference to the accompanying drawings and embodiments. The implementation process is as follows:

[0093] Step 1: Construct a segmented and refined P2G operation architecture. The traditional P2G process converts input electrical energy into natural gas through EL and MR equipment, generating a large amount of hydrogen in the process. Hydrogen is a green, zero-carbon, flexible, and efficient secondary energy source. Therefore, segmenting the electricity-to-gas process can fully utilize the hydrogen energy generated during the process.

[0094] The traditional power-to-gas (P2G) process is refined into two stages by combining a hydrogen fuel cell (HFC), an electrolyzer (EL), and a methane reactor (MR). In the first stage, the input electrical energy is converted into hydrogen energy via the EL, and the CO2 generated in the system is collected and stored by a CO2 collection device. In the second stage, a portion of the hydrogen energy is used as an intermediate input in the P2G process to synthesize natural gas with CO2 in the MR, while the other portion is directly converted into electricity and heat energy by the HFC. The remaining hydrogen energy is stored in a hydrogen storage tank. Compared to first synthesizing methane and then burning it with gas precipitate (GB) and carbon dioxide (CHP), direct hydrogen energy conversion via HFC reduces energy cascade losses. Furthermore, hydrogen has higher combustion efficiency than natural gas and produces no carbon emissions. The equipment model described above is as follows:

[0095] 1) EL device model:

[0096]

[0097] In the formula: P e,EL (t) represents the electrical energy input to EL during time period t; η is the hydrogen energy output by EL during time period t; EL The energy conversion efficiency of EL; These are the upper and lower limits of the electrical energy input to EL, respectively; These represent the upper and lower limits of EL's ramp rate, respectively.

[0098] 2) MR equipment model:

[0099]

[0100] In the formula: The hydrogen energy input to MR during time period t; P MR,g (t) represents the natural gas power output by MR during time period t; η MR The energy conversion efficiency of MR; These are the upper and lower limits of hydrogen energy input to MR, respectively; These represent the upper and lower limits of MR's ramp rate, respectively.

[0101] Step 2: Establish a combined heat and power (CHP) unit model based on adjustable heat and power ratio. On the basis of the coordinated operation of gas-fired CHP and hydrogen fuel cell (HFC) equipment, introduce adjustable heat and power ratio technology. Considering the P2G segmented refined operation architecture in Step 1, comprehensively construct an IES optimized operation model for electro-hydrogen production. This model enables the IES to adapt to the electric and heat load demand in different time periods and flexibly adjust the output strategy according to time-of-use electricity prices, thereby improving the economic efficiency of system operation.

[0102] The principle behind adjustable heat-to-power ratio (CHP) technology is as follows: by controlling the air intake of the generator set, the power generation is adjusted in real time. Simultaneously, the supplementary combustion boiler adjusts the heat supply by controlling the supplementary combustion amount; thus, the CHP system can be flexibly adjusted according to actual needs to maximize energy efficiency. Its working model is as follows:

[0103]

[0104] In the formula: P g,CHP (t) represents the natural gas power input to CHP during time period t; P CHP,e (t), P CHP,h (t) represents the electrical and thermal power output of CHP during time period t; These represent the efficiency of converting natural gas into electricity and heat, respectively. These are the upper and lower limits of the natural gas power input to CHP, respectively; These are the upper and lower limits of CHP power ramp-up, respectively. These are the upper and lower limits of the thermoelectric ratio of CHP, respectively.

[0105] Similarly, HFCs burn hydrogen for both power and heat supply. Traditional models have a fixed heat-to-power ratio and generally operate in a "heat-driven power generation" or "power-driven heat generation" mode, resulting in poor operational flexibility. By changing the flow rate of the cooling circulating water, the heat-to-power ratio can be adjusted according to the real-time electrothermal load. The working model is as follows:

[0106]

[0107] In the formula: P represents the hydrogen power input to the HFC during time period t; HFC,e (t), P HFC,h (t) represents the electrical and thermal power output of the HFC during time period t; η HFC,e η HFC,h These represent the efficiencies of HFC in converting energy into electricity and heat, respectively. These are the upper and lower limits of hydrogen energy input to HFCs, respectively. These represent the upper and lower limits of HFC ramp rate; These represent the upper and lower limits of the thermoelectric ratio of HFC.

[0108] The model established above is embedded into the P2G segmented refined operation model in step one to obtain the IES optimized operation model for electro-hydrogen production.

[0109] Step 3: Construct a joint trading market framework for carbon trading (CET) and green certificate trading (GCT) based on the green certificate-carbon trading interaction mechanism. This involves obtaining information on renewable energy generation and consumption within the integrated energy system through green certificate trading. By comparing the carbon emissions of renewable energy and traditional thermal power generation, the carbon emission reduction achieved by enterprises using green electricity relative to traditional electricity can be calculated. Under the green certificate-carbon trading interaction mechanism, IES can convert excess emissions into carbon emission allowances while obtaining green certificates.

[0110] To enhance the richness and flexibility of the electricity market, this invention constructs a joint trading market framework of CET and GCT. The combined effect of these two markets allows renewable energy output to be better integrated into the system. The specific trading mechanism framework proposed in this invention is as follows: Figure 4 As shown.

[0111] 1) GCT Mechanism. GCT can be used to verify and track the generation and source of renewable energy. The GCT mechanism converts the actual consumption of renewable energy generation into green certificates (referred to as green certificates). Renewable energy consumption quotas are determined by relevant regulatory authorities. Companies that fail to meet their quotas need to purchase green certificates from the market to meet their targets. Conversely, they can convert their renewable energy generation into green certificates for sale. This constrains the consumption of renewable energy by IES (Environmental Engineering Systems). The calculation method for green certificate transaction costs is as follows:

[0112]

[0113] In the formula: C GCT λ represents the transaction cost of green certificates; ρ represents the unit price of green certificate transactions; ρ represents the green certificate quota coefficient that IES needs to hold; δ represents the quantification coefficient for converting renewable energy generation into green certificates; P PV (t), P WT (t) represents the output power of distributed photovoltaic and wind power at time t, respectively; P e,Load (t) represents the electrical load at time t; P HFC,e (t) represents the electrical power generated by the hydrogen consumption of the HFC device at time t.

[0114] 2) CET Mechanism. The carbon trading mechanism is a market mechanism based on carbon emission rights. Producers formulate reasonable production plans based on carbon allowances issued by regulatory authorities. When actual carbon emissions exceed the available carbon emission allowances, they must purchase carbon emission rights in the carbon trading market; conversely, they can sell the remaining carbon emission allowances on the market. The calculation process for carbon emission costs can be expressed as follows:

[0115]

[0116] In the formula: C CET σ represents the carbon emission trading cost; k represents the unit carbon trading price; γ represents the tier length; and γ represents the unit price growth rate.st This refers to the carbon emissions trading volume.

[0117] The integrated energy system purchases electricity from its parent system via thermal power generation. Following the baseline method, the energy system's electricity purchases, CHP (Consumer Health Product), and GB (Gross National Standard) are the three sources of carbon emissions. Therefore, the specific carbon emissions can be expressed as:

[0118]

[0119] In the formula: P e,buy (t) represents the amount of electricity the system purchases from the grid during time period t; B stg For the carbon emissions generated; B s β1 represents the carbon emissions allocated per unit of power; β2 represents the carbon emissions allocated per unit of power; B MR ω represents the actual amount of CO2 absorbed by MR; ω is the CO2 absorption coefficient during the MR hydrogen-to-natural gas conversion process.

[0120] 3) GCT-CET Interaction Mechanism. Information on renewable energy generation and consumption within the system can be obtained through green certificate trading. Therefore, by comparing the carbon emissions of renewable energy and traditional thermal power generation, the carbon emission reduction of green electricity used by enterprises compared to traditional electricity can be calculated. The established green certificate-carbon trading interaction mechanism allows IES (Engineering, Procurement, and Construction) companies to partially convert green certificates into carbon emission allowances. The specific calculation method for this conversion is as follows:

[0121]

[0122] In the formula: B green Carbon emission allowances obtained by converting renewable energy power generation into green certificates; κ is the conversion coefficient.

[0123] In the normal trading mode of the green certificate market and the carbon trading market, the GCT-CET interaction mechanism forms a link between the two markets, thereby constructing a joint trading market framework for carbon trading (CET) and green certificate trading (GCT). Participants can plan their investment levels within this market framework, which greatly improves market flexibility.

[0124] Step 4: Based on the established joint trading market framework of carbon trading (CET) and green certificate trading (GCT) and the IES optimization operation model of hydrogen production from electricity, construct the objective function that minimizes the total operating cost. Taking into account renewable energy output constraints, grid power interaction constraints, energy storage constraints, equipment operation constraints, power balance constraints, and market trading constraints, construct a comprehensive energy system optimization operation model under the carbon-green certificate trading mechanism, embedding adjustable heat-to-power ratio and P2G segmented operation constraints. Solve the comprehensive energy system optimization operation model to achieve green certificate-carbon trading interaction optimization. Specific operations are as follows:

[0125] An integrated energy system optimization operation model is constructed under the carbon-green certificate trading mechanism, which incorporates adjustable heat-to-power ratio and P2G segmented operation constraints. The model consists of two parts: objective function and operation constraints.

[0126] Based on the aforementioned CET and GCT joint trading market framework, carbon trading costs and green certificate trading costs are obtained; based on the IES optimized operation model for hydrogen production via electricity, the energy purchase cost and curtailment cost of the IES are obtained. Taking into account the energy purchase cost of the IES... Cost of curtailment Carbon trading cost C CET Transaction costs of green certificates C GCT The objective function that minimizes the total operating cost F is constructed as follows:

[0127]

[0128] in:

[0129] Energy purchase cost for:

[0130]

[0131] In the formula: Let t be the interaction price between the power grid and the upstream power grid. Let P be the price of gas purchased from the upstream gas network at time t. g,buy (t) represents the amount of gas purchased from the upper-level gas network during time period t.

[0132] Cost of curtailment for

[0133]

[0134] Where: δ WT The cost of wind curtailment penalty per unit; P WT,cut (t) represents the wind curtailment power during time period t; δ PV The cost of per unit of abandoned light penalty; P PV,cut (t) represents the abandoned light power during time period t.

[0135] By establishing various operational constraints as boundary conditions for solving the objective function, the constraints proposed in this invention include:

[0136] 1) Renewable energy output constraints:

[0137]

[0138] In the formula: P WT (t) represents the wind power output during time period t; P represents the upper limit of wind power output. PV (t) represents the photovoltaic output power during time period t; This represents the upper limit of photovoltaic output power.

[0139] 2) Power constraints between power grids:

[0140]

[0141] In the formula: P grid (t) represents the power exchanged with the upstream power grid at time t. Let t be the maximum power exchanged with the upstream power grid.

[0142] 3) Energy storage operation constraints:

[0143] Since the models of electric, thermal, gas, and hydrogen energy storage devices are similar, a unified model is used to model the constraints of energy storage devices.

[0144]

[0145] In the formula: These represent the charging and discharging power of the nth type of energy storage device during time period t; Let the maximum power of the nth type of energy storage device during a single charge and discharge cycle be denoted as . All are binary variables, representing the charging and discharging state parameters of the nth type of energy storage device during time period t, P ES,n (t) represents the final output power of the nth type of energy storage device; These are the charging and discharging efficiencies of the nth type of energy storage device, respectively; S n (t) represents the real-time capacity of the nth type of energy storage device during time period t; Let n be the rated capacity of the nth type of energy storage device; These represent the upper and lower limits of the capacity of the nth type of energy storage device, respectively.

[0146] 4) Energy purchase constraints:

[0147]

[0148] In the formula: These are the limits for purchasing gas and electricity for different time periods.

[0149] 5) Power balance constraints:

[0150] P e,buy (t)=P e,Load (t)+P e,EL (t)+P ES,e (t)-P WT (t)-P HFC,e (t) (16)

[0151] In the formula: P ES,e (t) represents the power input to the energy storage device during time period t.

[0152] 6) Gas power balance constraint:

[0153] P g,buy (t)=P g,Load (t)+P ES,g (t)+P g,CHP (t)+P g,GB (t)-P MR,g (t) (17)

[0154] In the formula: P g,Load (t) represents the gas load during time period t; P ES,g (t) represents the power input to the energy storage device during time period t.

[0155] 7) Thermal power balance constraint:

[0156] P HFC,h (t)+P CHP,h (t)+P GB,h (t)=P h,Load (t)+P ES,h (t) (18)

[0157] In the formula: P h,Load (t) represents the heat load during time period t; P ES,h (t) represents the power input to the thermal storage device during time period t.

[0158] 8) Hydrogen balance constraint:

[0159]

[0160] In the formula: The power input to the hydrogen storage device during time period t.

[0161] 9) Carbon market constraints:

[0162]

[0163] In the formula: C CET,i and C CET,o These represent the total amount of carbon emission rights that IES purchases and sells to external carbon markets, respectively. and These represent the existing stock and the upper limit of carbon emission rights in the market, respectively.

[0164] 10) Constraints in the green certificate market:

[0165]

[0166] In the formula: C GCT,i and C GCT,o These represent the number of green certificates that IES buys and sells to the green certificate market, respectively. and These represent the existing stock and the maximum shortfall of green certificates in the market, respectively; Btra The number of green certificates converted into carbon allowances; B GCT This represents the number of green certificates traded in the market.

[0167] The models established in this invention are all mixed-integer linear programming models. The integrated energy system optimization operation model is solved using the YALMIP toolbox and CPLEX solver on the MATLAB software platform, realizing the green certificate-carbon trading interaction optimization.

[0168] Step 5: By setting up an experimental group and comparing it with the integrated energy system green certificate-carbon trading interaction optimization operation scheme proposed in this invention, which considers adjustable heat-to-power ratio and P2G segmented operation, the green and low-carbon nature and economic feasibility of the proposed model are verified.

[0169] The specific energy flow diagram of the IES that integrates multiple energy sources in this invention is as follows: Figure 6 As shown, a segmented P2G operation architecture based on an adjustable thermoelectric ratio is constructed as follows: Figure 3 As shown, through a joint trading model of carbon trading and green certificate trading, renewable energy output can be better integrated into the system. The specific operational framework of the green certificate-carbon trading interaction mechanism is as follows: Figure 4 As shown in the table. Finally, to verify the synergistic optimization effect of the proposed model on system operation economy and low-carbon green development, an IES in a park in Northwest China was selected as a case study for verification. The scheduling cycle is 24 hours a day. The main parameters of each energy conversion device in the IES are shown in Table 1, and the parameters of each energy storage device are shown in Table 2.

[0170] Table 1 Parameters of Energy Conversion Equipment

[0171] EL 500 87 100 MR 250 60 50 HFC 250 95 50 GB 800 95 160 CHP 600 92 120

[0172] Table 2 Parameters of Energy Storage Devices

[0173] Energy storage 450 90、10 90 thermal storage 500 90、10 100 Gas storage 150 90、10 30 hydrogen storage 200 90、10 40

[0174] To demonstrate the model's flexible scheduling capabilities, time-of-use pricing is adopted, with specific prices as follows: Figure 1 As shown, the various loads and the projected output curves of renewable energy in this region are as follows: Figure 2 As shown. The scheduling models established in this invention are all mixed-integer linear programming models. The IES optimization running model is solved using the YALMIP toolbox and CPLEX solver on the MATLAB software platform.

[0175] 2. Analysis of the Green Certificate-Carbon Trading Interaction Mechanism

[0176] To verify the effectiveness of the green certificate-carbon trading interaction mechanism proposed in this invention, three operating schemes were set up for comparative analysis of optimization results. Scheme 1: IES operation without considering the green certificate-carbon trading interaction mechanism; Scheme 2: IES operation considering only the carbon trading mechanism; Scheme 3: IES operation considering the green certificate-carbon trading interaction mechanism. The optimization comparison results of the three schemes are shown in Table 3.

[0177] Table 3 Comparison of Benefits Before and After Considering the Green Certificate-Carbon Trading Interaction Mechanism

[0178]

[0179] 3. Energy efficiency analysis of segmented operation of P2G with adjustable electrothermal ratio

[0180] To verify the effectiveness of the proposed P2G segmented refined operation model under the green certificate-carbon trading interaction mechanism, two additional schemes were set up for comparative analysis with Scheme 3. Scheme 4: The system uses traditional P2G equipment for power generation; Scheme 5: The traditional P2G equipment is replaced with a combination of EL, MR, and HFC equipment for segmented joint operation. The operating results under the two schemes are shown in Table 4. The specific system heat-to-power ratio adjustment is as follows: Figure 5 As shown.

[0181] Table 4 Comparison of Benefits Before and After P2G Segmented Operation

[0182]

[0183] The above description, in conjunction with specific / preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. Those skilled in the art can make various substitutions or modifications to these described embodiments without departing from the inventive concept, and all such substitutions or modifications should be considered within the scope of protection of the present invention.

[0184] The parts of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A method for optimizing the operation of a comprehensive energy system considering electricity market transactions, characterized in that, Includes the following steps: Step 1: Construct a segmented and refined P2G runtime architecture; Step 2: Establish a combined heat and power (CHP) unit model based on adjustable heat and power ratio. On the basis of the coordinated operation of gas-fired CHP and hydrogen fuel cell (HFC) equipment, introduce adjustable heat and power ratio technology. Considering the segmented and refined operation architecture of P2G in Step 1, comprehensively construct an IES optimized operation model for electro-hydrogen production. This model enables the IES to adapt to the electric and heat load demand in different time periods and flexibly adjust the output strategy according to the time-of-use electricity price, thereby improving the economic efficiency of system operation. Step 3: Construct a joint trading market framework for carbon trading (CET) and green certificate trading (GCT) based on the green certificate-carbon trading interaction mechanism; 1) GCT Mechanism; GCT can be used to verify and track the generation and source of renewable energy. The GCT mechanism converts the actual consumption of renewable energy generation into green certificates (referred to as green certificates). The renewable energy consumption quota is determined by relevant regulatory authorities. Companies that fail to meet their quotas need to purchase green certificates from the market to meet their quota targets. Conversely, they can convert their renewable energy generation into green certificates for sale; thus constraining the consumption of renewable energy by IES (Environmental Engineering Systems). The calculation method for green certificate transaction costs is as follows: （5） In the formula: For green certificate transaction costs; The unit price for green certificate transactions; This represents the green certificate quota coefficient that IES needs to hold; A quantitative coefficient for converting renewable energy power generation into green certificates; , They are time points Output power of distributed photovoltaic and wind power; for Electrical load at any given moment; for The electrical power generated by hydrogen consumption in the HFC unit at any given moment; 2) CET Mechanism; The carbon trading mechanism is a market mechanism based on carbon emission rights; producers formulate reasonable production plans based on carbon allowances issued by regulatory authorities. When actual carbon emissions exceed the available carbon emission allowances, they need to purchase carbon emission rights in the carbon trading market; conversely, they can sell the remaining carbon emission allowances in the market. The calculation process of carbon emission costs can be expressed as follows: （6） In the formula: Costs associated with carbon emissions trading; The price is the unit price for carbon trading. The length of the step; This represents the unit price growth rate. For carbon emissions trading volume; The integrated energy system purchases electricity from its superior power source through thermal power generation. Following the baseline method, the energy system's electricity purchases, CHP (Consumer Health Product), and GB (Gross National Energy Administration) constitute the sources of carbon emissions. Therefore, the specific carbon emissions can be expressed as: （7） In the formula: for The electricity purchased from the power grid during specific time periods; The amount of carbon emissions generated; The allocated carbon emissions; Carbon emissions per unit of power; Carbon emissions per unit of power; This represents the actual amount of CO2 absorbed by the MR. The CO2 absorption coefficient during the MR hydrogen-to-natural gas conversion process; 3) GCT-CET Interaction Mechanism: Information on renewable energy generation and consumption within the system can be obtained through green certificate trading. Therefore, by comparing the carbon emissions of renewable energy and traditional thermal power generation, the carbon emission reduction of green electricity used by enterprises relative to traditional electricity can be calculated. Through the established green certificate-carbon trading interaction mechanism, IES can partially convert green certificates into carbon emission allowances while obtaining them. The specific calculation method for this conversion is as follows: （8） In the formula: Carbon emission allowances obtained by converting renewable energy power generation into green certificates; The conversion factor; In the normal trading mode of the green certificate market and the carbon trading market, the GCT-CET interaction mechanism forms a link between the two markets, thereby constructing a joint trading market framework for carbon trading CET and green certificate trading GCT. Step 4: Based on the established joint trading market framework of carbon trading (CET) and green certificate trading (GCT) and the IES optimized operation model of hydrogen production from electricity, construct the objective function that minimizes the total operating cost. Taking into account renewable energy output constraints, grid power interaction constraints, energy storage constraints, equipment operation constraints, power balance constraints, and market trading constraints, construct a comprehensive energy system optimized operation model with embedded adjustable heat-to-power ratio and P2G segmented operation constraints under the carbon-green certificate trading mechanism. Solve the comprehensive energy system optimized operation model to achieve green certificate-carbon trading interaction optimization.

2. The method for optimizing the operation of a comprehensive energy system considering electricity market transactions according to claim 1, characterized in that, The specific method for step 1 is as follows: The traditional power-to-gas (P2G) process is refined into two stages by combining a hydrogen fuel cell (HFC), an electrolyzer (EL), and a methane reactor (MR). In the first stage, the input electrical energy is converted into hydrogen energy via the EL, and the CO2 generated in the system is collected and stored by a CO2 collection device. In the second stage, a portion of the hydrogen energy is used as an intermediate input in the P2G process to synthesize natural gas with CO2 in the MR, while the other portion is directly converted into electricity and heat energy by the HFC. The remaining hydrogen energy is stored in a hydrogen storage tank. The equipment model described above is as follows: 1) EL device model: （1） In the formula: for The electrical energy input to EL during the specified time period; for Hydrogen energy output by EL during the time period; The energy conversion efficiency of EL; , These are the upper and lower limits of the electrical energy input to EL, respectively; , These represent the upper and lower limits of EL's ramp rate, respectively. 2) MR equipment model: （2） In the formula: for Hydrogen energy input to MR during the time period; for Natural gas power output by MR during the time period; The energy conversion efficiency of MR; , These are the upper and lower limits of hydrogen energy input to MR, respectively; , These represent the upper and lower limits of the MR climb rate.

3. The method for optimizing the operation of a comprehensive energy system considering electricity market transactions according to claim 2, characterized in that, The specific method for step two is as follows: The principle behind the adjustable heat-to-power ratio (CHP) technology is as follows: by controlling the air intake of the generator set, the power generation is adjusted in real time; at the same time, the supplementary combustion boiler adjusts the heat supply by controlling the supplementary combustion amount; thus, the CHP system can be flexibly adjusted according to actual needs to maximize energy utilization efficiency. Its working model is as follows: （3） In the formula: for The natural gas power input to CHP during the specified time period; , They are respectively The electrical and thermal power output of CHP during the time period; , These represent the efficiency of converting natural gas into electricity and heat, respectively. , These are the upper and lower limits of the natural gas power input to CHP, respectively; , These are the upper and lower limits of CHP power ramp-up, respectively. , These are the upper and lower limits of the thermoelectric ratio of CHP, respectively. Similarly, HFCs burn hydrogen for both power and heat supply. By changing the flow rate of the cooling circulating water, the heat-to-power ratio can be adjusted according to the real-time electrothermal load. The working model is as follows: （4） In the formula: for Hydrogen power input to HFC during the time period; , They are respectively The electrical and thermal power output of HFC during the time period; , These represent the efficiencies of HFC in converting energy into electricity and heat, respectively. , These are the upper and lower limits of hydrogen energy input to HFCs, respectively. , These represent the upper and lower limits of HFC ramp rate; , These are the upper and lower limits of the thermoelectric ratio of HFC, respectively. The model established above is embedded into the P2G segmented refined operation model in step one to obtain the IES optimized operation model for electro-hydrogen production.

4. The method for optimizing the operation of a comprehensive energy system considering electricity market transactions according to claim 3, characterized in that, The specific method for step four is as follows: A comprehensive energy system optimization operation model is constructed under the carbon-green certificate trading mechanism, which incorporates adjustable heat-to-power ratio and P2G segmented operation constraints, including two parts: objective function and operation constraints. Based on the aforementioned CET and GCT joint trading market framework, carbon trading costs and green certificate trading costs are obtained; based on the IES optimized operation model for hydrogen production by electricity, the energy purchase cost and curtailment cost of the IES are obtained; taking into account the energy purchase cost of the IES... Cost of energy curtailment Carbon trading costs Transaction costs of green certificates The objective function that minimizes the total operating cost F is constructed as follows: （9） in: Energy purchase cost for: （10） In the formula: for The interactive electricity price between the power grid and the higher-level power grid at all times. for Always check gas prices online from higher-level suppliers; for The time period is determined by the amount of gas purchased from the superior gas network; Cost of curtailment for （11） In the formula: The cost of wind curtailment penalty per unit; for Wind curtailment power during the period; Cost of per unit of abandoned light penalty; for The amount of light discarded during a given period; By establishing various operational constraints as boundary conditions for solving the objective function, the proposed constraints include: 1) Renewable energy output constraints: （11） In the formula: for Wind power output during specific time periods; This is the upper limit of wind power output; for Photovoltaic output power during the period; This represents the upper limit of photovoltaic output power. 2) Power constraints between power grids: （13） In the formula: for Constantly interacting with the upstream power grid for power. for Maximum power exchanged with the upstream power grid at all times; 3) Energy storage operation constraints: Since the models of electric, thermal, gas, and hydrogen energy storage devices are similar, a unified model is used to model the constraints of energy storage devices. （14） In the formula: , The first Type of energy storage device Charging and discharging power during the time period; For the first The maximum charge and discharge power of this type of energy storage device during a single charge / discharge cycle; , All are binary variables, respectively the first... Type of energy storage device Time period charging and discharging status parameters, For the first The final output power of this type of energy storage device; , The first The charging and discharging efficiency of this type of energy storage device; For the first Type of energy storage device Real-time capacity for a given time period; For the first The rated capacity of the energy storage device; , The first The upper and lower limits of the capacity of this type of energy storage device; 4) Energy purchase constraints: （15） In the formula: , These are the gas and electricity purchase limits for different time periods; 5) Power balance constraints: （16） In the formula: for The power input to the energy storage device during the time period; 6) Gas power balance constraint: （17） In the formula: for Gas load during the period; for The power input to the energy storage device during the time period; 7) Thermal power balance constraint: （18） In the formula: for Heat load during the period; for The power input to the thermal storage device during the time period; 8) Hydrogen balance constraint: （19） In the formula: for The power input to the hydrogen storage device during the time period; 9) Carbon market constraints: （20） In the formula: and These represent the total amount of carbon emission rights that IES purchases and sells to external carbon markets, respectively. and These represent the existing stock and the upper limit of carbon emission rights in the market, respectively. 10) Constraints in the green certificate market: （21） In the formula: and These represent the number of green certificates that IES buys and sells to the green certificate market, respectively. and These represent the existing stock of green certificates in the market and the upper limit of the shortfall; The number of green certificates converted into carbon allowances; The number of green certificates traded in the market; The YALMIP toolbox and CPLEX solver were used on the MATLAB software platform to solve the integrated energy system optimization operation model.

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