Regional integrated energy system master-slave game optimization method considering energy gradient utilization

Abstract

The invention provides a regional integrated energy system master-slave game optimization method considering energy gradient utilization. The method comprises the following steps: S1, establishing a regional integrated energy system structure containing a gradient energy supply link; s2, building a master-slave game framework of participation of multiple subjects in the market transaction and decision models of the subjects; s3, formulating a master-slave game equilibrium solution; s4, acquiring initial data of loads and electric heat prices of the system; and S5, solving the model. According to user demand differences, a regional integrated energy system model containing an energy gradient utilization link is constructed, pricing methods of different grades of heat energy are provided, and each subject decision model is given according to an energy transaction process. Models of an integrated energy system operator and an integrated load aggregator are improved, and the economy and feasibility of the proposed models are verified through example comparison. Example analysis shows that by introducing the energy gradient utilization link, the income of an integrated energy system operator and an energy supplier can be improved, and the energy efficiency of the system can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of energy management technology, and specifically to a master-slave game optimization operation method for a regional integrated energy system taking into account energy cascade utilization. Background Art

[0002] Energy cascade utilization can be reasonably matched according to the quality and quality of energy, avoiding the waste of high-quality energy, and can better play the advantages of efficient and clean energy supply in the integrated energy system. However, the existing technology mainly focuses on the cascade utilization of cold energy. For example, Chinese patent document CN215638193U records the scheduling method of liquefied natural gas cold energy cascade utilization participating in the integrated energy system. Regarding the supply of thermal energy, no fine distinction is made, resulting in low energy utilization efficiency of the system and a serious problem of energy waste.

[0003] In energy market transactions, different energy prices affect the trading strategies of different entities. Master-slave game, as a mechanism to describe the participation of multiple entities in market transactions, can optimize the benefits of each entity according to the decision-making strategies of different entities. However, most existing studies focus on the interactive behaviors among multiple entities. For example, "Distributed Collaborative Optimization Operation Strategy of Community Integrated Energy System Based on Master-slave Game" analyzes the energy trading process of multiple entities in the community integrated energy system, but does not conduct in-depth research on the impact of changes in the internal strategies of a single entity, which is not conducive to optimizing market resource allocation and energy conservation and emission reduction potential. Therefore, studying the master-slave game optimization operation method of regional integrated energy system with energy cascade utilization is of great significance to improving energy utilization efficiency and accelerating the construction of a modern energy market. Summary of the invention

[0004] The present invention provides a master-slave game optimization operation method for a regional comprehensive energy system considering energy cascade utilization, constructs a regional comprehensive energy system model containing energy cascade utilization links, and establishes a master-slave game framework in which comprehensive energy system operators, energy suppliers, and comprehensive load aggregators participate in market transactions; then, energy storage equipment and incentive-type demand response are added to further improve the flexible adjustment capability of the system and tap the high energy efficiency potential of the system; through example comparison and analysis, the impact of energy cascade utilization and demand response on the economic efficiency of various entities participating in market transactions is analyzed.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: The master-slave game optimization operation method of regional comprehensive energy system considering energy cascade utilization includes the following steps: S1. According to the relationship between different thermal energy qualities, establish a regional comprehensive energy system structure with cascade energy supply links; S2. Build a master-slave game framework for multiple entities to participate in market transactions and a decision-making model for each entity; S3, formulation of equilibrium solutions for the master-slave game; S4. Obtaining initial data of system loads and electricity and heat prices; S5. Solve the model, determine the equilibrium convergence of the master-slave game, and obtain the optimal master-slave game operation method.

[0006] In the above-mentioned S1, the regional integrated energy system structure with cascade energy supply links can be divided into steam heat, high temperature heat and medium temperature heat according to its temperature. The produced energy is divided into different grades through energy conversion equipment and storage equipment, and then supplied according to load demand. The energy production equipment in the system includes gas turbines and gas boilers; the energy conversion equipment includes electric heat pumps, electric refrigerators, absorption refrigerators, absorption heat pumps and peak heaters; the energy storage equipment includes electrical energy storage and thermal energy storage; electric heat pumps and electric refrigerators convert electrical energy into medium-grade heat energy and cold energy; absorption heat pumps and peak heaters convert input heat energy into different grades of heat energy output.

[0007] In the master-slave game framework of the multi-agent market transaction in S2 mentioned above, the integrated energy system operator, energy supplier, and integrated load aggregator formulate operation strategies according to their own benefit functions and optimize the output of internal equipment to ensure the balance of energy supply and demand; During the energy trading process, the integrated energy system operator, as the leader, first formulates the purchase price of electricity and heat, the selling price of electricity and the highest-grade steam heat price based on the supply and demand relationship and market information. The energy supplier obtains the optimal output power based on its own benefit function, and the integrated load aggregator formulates the actual electricity and heat load requirements based on the price to ensure the maximum satisfaction surplus; the followers upload the optimal strategy to the integrated energy system operator, and the integrated energy system operator optimizes its own profits by minimizing the operating cost of the energy cascade utilization link.

[0008] The above-mentioned subject decision model of S2 includes: Integrated Energy System Operators: Integrated energy system operator; its objective function can be expressed as: ; Where: Revenue for supplying energy to load aggregators; The cost of purchasing energy from energy suppliers; is the grid interaction cost; The operation and maintenance cost of energy storage equipment; The operation and maintenance costs of energy cascade utilization equipment; is the response subsidy given to the load aggregator; the expressions of each item are: ; Where: ; is the energy purchase cost of the load aggregator, The energy sales revenue for energy suppliers, is the power purchased from the grid. When it is positive, it means purchasing power, and vice versa, it means selling power to the grid. , Absorbing and emitting power for electrical energy storage; , The absorption and emission of thermal energy storage; is the price of electricity sold by the grid, For the on-grid electricity price; , , They are the unit output power operation and maintenance prices of electric energy storage, thermal energy storage equipment and energy conversion equipment respectively; Energy Suppliers: The energy supplier determines the internal equipment output according to the electricity and heat prices set by the operator. The optimization goal is to maximize the profit. The objective function can be expressed as: ; Where: To earn revenue from the sale of energy to system operators; for the cost of fuel; Operation and maintenance costs of energy production equipment; The cost of wind curtailment; is the abandoned light cost; the expressions of each item are: ; Where: ; , The electrical and thermal power exported to energy suppliers; , The electricity and heat purchase prices issued by operators; , , , is the cost coefficient; For equipment The unit output power operation and maintenance price; For equipment exist Output power at the moment; , The unit price of abandoned wind and solar power; , The abandoned wind and solar power. In addition, the following constraints must be met: ; Where: , The wind power and photovoltaic power absorbed by the system; , The power generation efficiency and heat generation efficiency of the gas turbine; , Equipment Maximum and minimum output power; , Equipment The landslide rate and climbing rate; Comprehensive Load Aggregator: The integrated load aggregator conducts incentive-based demand response based on the electricity and heat prices set by the operator. The optimization goal is to maximize the user satisfaction surplus. Its objective function can be expressed as: ; Where: The residual satisfaction after user demand response; Subsidies given by operators to users after receiving demand response; is the user's energy purchase cost; the expressions of each item are: ; Where: , , , are the user’s preference coefficients for electric energy and medium-temperature thermal energy, respectively; is the actual electrical load power; is the actual medium temperature heat load power; , The electric load that can be shifted and the medium-temperature heat load that can be curtailed are formulated after the load aggregator responds to the demand; , The unit price of subsidies for shiftable electrical loads and curtailable medium-temperature thermal loads; , is the actual steam heat load power and the actual high temperature heat load power; , The electricity price and the highest-grade steam heat price sold by the operator; the actual electricity load and medium-temperature heat load of the user can be expressed as: ; Where: , For fixed electric loads and transferable electric loads; , The fixed medium-temperature heat load and the reducible medium-temperature heat load are the user groups of steam load and high-temperature load. The user groups of steam load and high-temperature load are industrial loads. In order to ensure the uninterrupted supply of industrial heat load, the reducible heat load is not considered. The user groups of medium-temperature load are commercial users and residential users. Their reducible heat load is considered. In addition, the shiftable electric load and the reducible medium-temperature heat load must also meet the following constraints: ; Where: , It can shift the electrical load and reduce the upper limit of the medium temperature heat load. The total amount of load that can be moved in one day.

[0009] The constraints of the above S2 subject decision model are as follows: Price constraints: The prices set by operators should meet the following constraints: ; Where: Indicates 24 hours a day; , The minimum and maximum prices for thermal energy; is the average electricity selling price; is the average hot selling price; Power Constraints: For the system to operate normally, it is necessary to balance the supply and demand of electricity, heat and cooling, that is, to meet the following constraints: ; Where: is the cooling load power.

[0010] In the master-slave game equilibrium of S3 above, the master-slave game model can be expressed as: ; The model covers the three elements of the game: game subjects, decision variables and benefit functions; among them, the game subjects are mainly operators, energy suppliers and load aggregators; the decision variables are the purchase and sale prices of electricity and heat set by the operators. , the electric heating power output by the energy supplier , the load aggregator can transfer the electric load and reduce the medium temperature heat load in each period ; The benefit function is the objective function of each subject; Based on the electricity and heat prices issued by the leader, the followers make the best strategy and are accepted by the leader. The game reaches the Nash equilibrium, that is, when the following equation is satisfied, there is an equilibrium solution: : .

[0011] In the above S5, the article model is determined according to the objective function of each subject participating in the game, and the genetic algorithm combined with quadratic programming is used to solve the model; among them, the upper-level operator strategy is solved by genetic algorithm, and the lower-level energy supplier and load aggregator strategy is solved by quadratic programming; the model is solved by simulation using the CPLEX solver of the MATLAB platform.

[0012] The present invention provides a master-slave game optimization method for regional integrated energy systems considering energy cascade utilization, introduces the energy cascade utilization link into the energy market transaction process, and constructs a master-slave game framework including energy suppliers, improved integrated energy system operators and load aggregators. Through comparative analysis of different examples, it has the following beneficial effects: 1) Introducing energy cascade utilization into system operators and considering incentive-based demand response into load aggregators can reduce system energy consumption and increase the profits of system operators and energy suppliers. Compared with the scheme without considering energy cascade utilization and demand response, the energy utilization efficiency of the proposed scheme is improved by 13.774%, the profits of system operators are increased by 783.19 yuan, and the profits of energy suppliers are increased by 954.112 yuan.

[0013] 2) The incentive-based demand response considered by load aggregators is closer to reality and is conducive to reducing the amount of wind and solar power curtailment from renewable energy sources; the introduction of electricity and heat storage equipment by system operators can improve the flexible adjustment capabilities of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a schematic diagram of the structure of a regional comprehensive energy system including a cascade energy supply link of the present invention; Figure 2 It is a schematic diagram of the master-slave game framework structure in which multiple subjects participate in market transactions in the present invention; Figure 3 It is a schematic diagram of the power curve of each load; Figure 4 It is a schematic diagram of the convergence of the master-slave game equilibrium; Figure 5 It is a schematic diagram of the electricity and heat price curve; Figure 6 It is a schematic diagram of the electric load curve before and after demand response; Figure 7 It is a schematic diagram of the medium temperature heat load curve before and after demand response; Figure 8 This is a schematic diagram of the actual typical day wind and solar power consumption results; Fig. 9 It is a schematic diagram of power supply and demand balance. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following content will systematically and completely describe the specific technical solutions of the present invention in combination with the drawings provided according to the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] Embodiment 1: The master-slave game optimization operation method of regional comprehensive energy system considering energy cascade utilization includes the following steps: S1. According to the relationship between different thermal energy qualities, establish a regional comprehensive energy system structure with cascade energy supply links; S2. Build a master-slave game framework for multiple entities to participate in market transactions and a decision-making model for each entity; S3, formulation of equilibrium solutions for the master-slave game; S4. Obtaining initial data of system loads and electricity and heat prices; S5. Solve the model, determine the equilibrium convergence of the master-slave game, and obtain the optimal master-slave game operation method.

[0017] Hot price by grade Energy is a commodity, and its quality and quantity can affect its price. Energy quality coefficient, as a key indicator to measure energy quality, reflects the ability of total energy in energy to be converted into useful work. Electricity, as an energy that can be completely converted into work, has an energy quality coefficient of 1; steam is a secondary energy source, and its energy quality coefficient is 0.27; high-temperature heat output has an energy quality coefficient of 0.2; and medium-temperature heat output has an energy quality coefficient of 0.16.

[0018] Regional integrated energy system structure with cascade energy supply links The energy flow structure of the regional integrated energy system with cascade energy supply links is as follows: Figure 1 As shown. In the process of energy distribution and consumption, there are differences in energy quality. Among them, thermal energy can be divided into steam heat, high temperature heat and medium temperature heat according to its temperature. Through energy conversion equipment and storage equipment, the produced energy can be divided into different grades, and then accurately supplied according to load demand.

[0019] Energy production equipment in the system includes gas turbines and gas boilers. Energy conversion equipment includes electric heat pumps, electric refrigerators, absorption refrigerators, absorption heat pumps, and peak heaters. Energy storage equipment includes electric energy storage and thermal energy storage. Among them, electric heat pumps and electric refrigerators convert electrical energy into medium-grade heat and cold energy. Absorption heat pumps and peak heaters convert input heat energy into different grades of heat output.

[0020] How it works Master-slave game framework The master-slave game framework containing the energy cascade utilization link is as follows Figure 2 The integrated energy system operators, energy suppliers, and integrated load aggregators formulate operation strategies based on their own benefit functions and optimize the output of internal equipment to ensure the balance of energy supply and demand.

[0021] In the energy trading process, the integrated energy system operator, as the leader, first formulates the purchase price of electricity and heat, the selling price of electricity and the highest-grade steam heat price according to the supply and demand relationship and market information. The energy supplier obtains the optimal output power according to its own benefit function, and the integrated load aggregator formulates the actual electricity and heat load requirements according to the price to ensure the maximum satisfaction surplus. The followers upload the optimal strategy to the integrated energy system operator, and the integrated energy system operator optimizes its own benefits by minimizing the operating cost of the energy cascade utilization link.

[0022] Decision-making model of each subject Integrated Energy System Operators: The operator of the integrated energy system acts as both a leader and a service provider in the entire system. The introduction of energy storage equipment can increase the flexibility of the system, and the introduction of energy cascade utilization can improve the energy utilization efficiency of the system. In order to encourage users to participate in demand response, subsidies are given according to the amount of demand response after users participate in demand response. Its objective function can be expressed as: ; Where: Revenue for supplying energy to load aggregators; The cost of purchasing energy from energy suppliers; is the grid interaction cost; The operation and maintenance cost of energy storage equipment; The operation and maintenance costs of energy cascade utilization equipment; is the response subsidy given to the load aggregator; the expressions of each item are: ; Where: ; is the energy purchase cost of the load aggregator, The energy sales revenue for energy suppliers, is the power purchased from the grid. When it is positive, it means purchasing power, and vice versa, it means selling power to the grid. , Absorbing and emitting power for electrical energy storage; , The absorption and emission of thermal energy storage; is the price of electricity sold by the grid, For the on-grid electricity price; , , They are the unit output power operation and maintenance prices of electric energy storage, thermal energy storage equipment and energy conversion equipment respectively; Energy Suppliers: The energy supplier determines the internal equipment output according to the electricity and heat prices set by the operator. The optimization goal is to maximize the profit. The objective function can be expressed as: ; Where: To earn revenue from the sale of energy to system operators; for the cost of fuel; Operation and maintenance costs of energy production equipment; The cost of wind curtailment; is the abandoned light cost; the expressions of each item are: ; Where: ; , The electrical and thermal power exported to energy suppliers; , The electricity and heat purchase prices issued by operators; , , , is the cost coefficient; For equipment The unit output power operation and maintenance price; For equipment exist Output power at the moment; , The unit price of abandoned wind and solar power; , The abandoned wind and solar power. In addition, the following constraints must be met: ; Where: , The wind power and photovoltaic power absorbed by the system; , The power generation efficiency and heat generation efficiency of the gas turbine; , Equipment Maximum and minimum output power; , Equipment The landslide rate and climbing rate; Comprehensive Load Aggregator: The integrated load aggregator conducts incentive-based demand response based on the electricity and heat prices set by the operator. The optimization goal is to maximize the user satisfaction surplus. Its objective function can be expressed as: ; Where: The residual satisfaction after user demand response; Subsidies given by operators to users after receiving demand response; is the user's energy purchase cost; the expressions of each item are: ; Where: , , , are the user’s preference coefficients for electric energy and medium-temperature thermal energy, respectively; is the actual electrical load power; is the actual medium temperature heat load power; , The electric load that can be shifted and the medium-temperature heat load that can be curtailed are formulated after the load aggregator responds to the demand; , The unit price of subsidies for shiftable electrical loads and curtailable medium-temperature thermal loads; , is the actual steam heat load power and the actual high temperature heat load power; , The electricity price and the highest-grade steam heat price sold by the operator; the actual electricity load and medium-temperature heat load of the user can be expressed as: ; Where: , For fixed electric loads and transferable electric loads; , The fixed medium-temperature heat load and the reducible medium-temperature heat load are the user groups of steam load and high-temperature load. The user groups of steam load and high-temperature load are industrial loads. In order to ensure the uninterrupted supply of industrial heat load, the reducible heat load is not considered. The user groups of medium-temperature load are commercial users and residential users. Their reducible heat load is considered. In addition, the shiftable electric load and the reducible medium-temperature heat load must also meet the following constraints: ; Where: , It can shift the electrical load and reduce the upper limit of the medium temperature heat load. The total amount of load that can be moved in one day.

[0023] The constraints are as follows: Price constraints: To ensure that the problem is established, the price set by the operator should meet the following constraints: ; Where: Indicates 24 hours a day; , The minimum and maximum prices for thermal energy; is the average electricity selling price; is the average hot selling price; Power Constraints: For the system to operate normally, it is necessary to balance the supply and demand of electricity, heat and cooling, that is, to meet the following constraints: ; Where: is the cooling load power.

[0024] Master-slave game equilibrium The optimal output and actual load demand set by energy suppliers and load aggregators are based on the prices set by operators. When setting prices, operators must also fully consider the optimal strategies of energy suppliers and load aggregators. Therefore, the master-slave game model has a Nash equilibrium solution; the master-slave game model can be expressed as: ; The model covers the three elements of the game: game subjects, decision variables and benefit functions; among them, the game subjects are mainly operators, energy suppliers and load aggregators; the decision variables are the purchase and sale prices of electricity and heat set by the operators. , the electric heating power output by the energy supplier , the load aggregator can transfer the electric load and reduce the medium temperature heat load in each period ; The benefit function is the objective function of each subject; Based on the electricity and heat prices issued by the leader, the followers make the best strategy and are accepted by the leader. The game reaches the Nash equilibrium, that is, when the following equation is satisfied, there is an equilibrium solution: : .

[0025] Model solving and simulation analysis Model solving and parameter setting According to the objective function of each subject involved in the game, the article model uses genetic algorithm combined with quadratic programming to solve the constructed model. Among them, the upper-level operator strategy is solved by genetic algorithm, and the lower-level energy supplier and load aggregator strategy is solved by quadratic programming. The constructed model is solved by simulation using the CPLEX solver on the MATLAB platform.

[0026] The example takes the regional integrated energy system as the research object, optimizes and solves it in units of one day, and verifies the efficiency improvement and feasibility of the proposed scheme on the system. The actual typical daily data of a certain area in northern winter are selected, and the load side electrical load, steam heat load, high temperature heat load, medium temperature heat load, and cooling load are as follows: Figure 3 shown.

[0027] Simulation Results Analysis In order to compare and analyze the improvement of system benefits by cascade utilization and demand response, four examples are set for comparative analysis. The specific scenarios are as follows: Scenario 1: Without considering the cascade utilization link and load-side demand response, all heat loads are uniformly converted into medium-temperature heat loads, and peak heaters, absorption chillers and absorption heat pumps are disabled.

[0028] Scenario 2: Without considering the cascade utilization link, but taking demand response into consideration, all heat loads are uniformly converted into medium-temperature heat loads, and peak heaters, absorption chillers and absorption heat pumps are disabled.

[0029] Scenario 3: Considering the cascade utilization link, but not considering demand response.

[0030] Scenario 4: Consider cascade utilization and demand response.

[0031] The operation results of the above four scenarios are shown in Table 1. Compared with scenario 1 and scenario 2, scenario 2 takes demand response into account at the user end, prompting the user to reduce the thermal load, thereby reducing the energy required by the entire system. From the perspective of the benefits of the various entities participating in the market transaction, the operator's revenue increased by 217.18 yuan, the revenue of the energy supplier and load aggregator increased slightly, and the energy supplier saved 260.36m³ of gas. The energy utilization efficiency formula can be used to calculate that the energy utilization efficiency of scenario 2 is 2.178% higher than that of scenario 1. Considering demand response on the load side can promote energy coupling within the system, thereby improving energy efficiency.

[0032] Table 1 Operation results in four scenarios

[0033] Comparing Scenario 1 and Scenario 3, Scenario 3 takes into account the tiered supply of thermal energy on the basis of Scenario 1. This link can accurately meet the user's demand for thermal energy of different grades. The graded supply of thermal energy can reduce energy waste, thereby reducing the energy required for the entire system. Compared with Scenario 1, the income of each subject in Scenario 3 has been greatly improved. Among them, the income of the operator increased by 628.11 yuan, the income of the energy supplier increased by 859.192 yuan, and the income of the load aggregator increased by 132.54 yuan. Compared with Scenario 1, the energy supplier in Scenario 3 saved 600.532m³ of gas, and the reduction in gas volume led to a significant increase in the income of the energy supplier. In Scenario 3, which adds a tiered thermal energy supply link, the energy utilization efficiency of the entire system is improved by 11.36%. Accurately matching load demand can reduce the energy required by the system and greatly improve the energy utilization efficiency of the system.

[0034] Compared with Scenario 1, Scenario 4 increased the operator's revenue by 783.19 yuan, the energy supplier's revenue by 954.112 yuan, and the load aggregator's revenue by 183.18 yuan. Scenario 4 takes into account the hierarchical supply of thermal energy and demand response, and the energy required by the system is greatly reduced, which is reflected in the reduction of 814.565 m³ of gas required by the energy supplier, and the energy utilization efficiency is improved by 13.774% compared with Scenario 1. Scenario 2 compared with Scenario 1, and Scenario 4 compared with Scenario 3, both introduce demand response on the load side. Although demand response reduces the energy required by the system, considering that energy suppliers will absorb more wind and solar power to increase their own profits, thereby reducing fuel costs, the cost of abandoning wind and solar power has decreased compared with Scenario 4 and Scenario 3, and compared with Scenario 2 and Scenario 1.

[0035] Taking into account scenarios 2 and 3, the thermal energy hierarchical supply considered in scenario 3 can significantly reduce the energy required by the system compared to the demand response considered in scenario 2, and improve the overall benefits of the system more significantly, as shown by an increase of 410.93 yuan in operator revenue, 813.79 yuan in energy supplier revenue, a slight increase in load aggregator revenue, a 9.182% increase in system energy efficiency, and a 340.172 m³ reduction in supplier gas consumption. The significant reduction in the energy required by the system in scenario 3 reduces the amount of wind and solar power absorbed by the system, that is, the cost of abandoning wind and solar power increases.

[0036] Scheduling results analysis In order to further verify the feasibility of the model built in this article, the operation results of scenario 4 are analyzed. Figure 4 As shown in Figure 2, at the 40th time, the game equilibrium has been reached. When the game reaches equilibrium, the price curves for purchasing, selling electricity and heating set by the operator are as follows: Figure 5 shown.

[0037] The load side considers the load curve before and after demand response. Figure 6 As shown, the medium temperature heat load curve is as follows Figure 7 As shown. For the electric load, the load is increased during valley hours (0.00-4.00, 13.00-18.00), and the load is reduced during peak hours (5.00-11.00, 23.00-24.00). After optimization, the electric load can better achieve peak shaving and valley filling to ensure stable operation of the system. For medium-temperature thermal load, by reducing the thermal load at each moment, the energy required by the system can be reduced, and the energy utilization efficiency of the system can be improved while promoting the consumption of wind and solar energy. At the peak of wind and solar energy, the load side increases the load through demand response, and the excess wind and solar energy meet the supply and demand balance of the system by abandoning wind and solar energy. The actual wind and solar output and the abandonment of wind and solar energy on a typical day are shown as follows Figure 8 shown.

[0038] The supply and demand relationship of electricity and heat power is as follows Fig. 9 As shown by Fig. 9 As can be seen from the left, the system supplies electricity through wind power, photovoltaic power consumption, and gas turbine equipment, and consumes electricity through electric heating, electric cooling, and power load. When electricity is in oversupply, the system stores part of the electricity through power storage equipment, which improves the system's regulation ability, and sells the remaining part to the power grid to obtain revenue. When electricity is in short supply, the power storage equipment releases electric power to meet demand, and the shortfall is balanced by purchasing electricity from the power grid; Fig. 9 As can be seen from the right, the gas turbine generates heat while generating electricity, and the shortfall is made up by the output of the gas boiler. The heat demand includes the heat required by the steam heat load, peak heater, absorption heat pump, and absorption chiller. The introduction of heat storage equipment can adjust the thermal power balance of the system, thereby improving the flexibility of the system.

Claims

1. A master-slave game optimization method for regional integrated energy system considering energy cascade utilization, characterized in that: The following steps are involved: S1. According to the relationship between different thermal energy qualities, establish a regional comprehensive energy system structure with cascade energy supply links; S2. Build a master-slave game framework for multiple entities to participate in market transactions and a decision-making model for each entity; S3, formulation of equilibrium solutions for master-slave games; S4. Obtaining initial data of each load and electricity and heat price of the system; S5. Solve the model, determine the equilibrium convergence of the master-slave game, and obtain the optimal master-slave game operation method.

2. According to the master-slave game optimization method of regional comprehensive energy system considering energy cascade utilization as described in claim 1, it is characterized in that: The regional integrated energy system structure with cascade energy supply links in S1 described above, thermal energy can be divided into steam heat, high temperature heat and medium temperature heat according to its temperature; the produced energy is divided into different grades through energy conversion equipment and storage equipment, and then supplied according to load demand; The energy production equipment in the system includes gas turbines and gas boilers; the energy conversion equipment includes electric heat pumps, electric refrigerators, absorption refrigerators, absorption heat pumps and peak heaters; the energy storage equipment includes electrical energy storage and thermal energy storage; electric heat pumps and electric refrigerators convert electrical energy into medium-grade heat energy and cold energy; absorption heat pumps and peak heaters convert input heat energy into different grades of heat energy output.

3. According to the master-slave game optimization operation method of regional comprehensive energy system considering energy cascade utilization as described in claim 1, it is characterized in that: In the master-slave game framework of S2 where multiple entities participate in market transactions, the integrated energy system operator, energy supplier, and integrated load aggregator formulate operation strategies based on their own benefit functions and optimize the output of internal equipment to ensure the balance of energy supply and demand; During the energy trading process, the integrated energy system operator, as the leader, first formulates the purchase price of electricity and heat, the selling price of electricity and the highest-grade steam heat price based on the supply and demand relationship and market information. The energy supplier obtains the optimal output power based on its own benefit function, and the integrated load aggregator formulates the actual electricity and heat load requirements based on the price to ensure the maximum satisfaction surplus; the followers upload the optimal strategy to the integrated energy system operator, and the integrated energy system operator optimizes its own profits by minimizing the operating cost of the energy cascade utilization link.

4. The master-slave game optimization operation method of the regional comprehensive energy system considering the energy cascade utilization according to claim 3 is characterized in that: The subject decision model of S2 includes: Integrated Energy System Operators: Integrated energy system operator; its objective function can be expressed as: ； Where: Revenue for supplying energy to load aggregators; The cost of purchasing energy from energy suppliers; is the grid interaction cost; The operation and maintenance cost of energy storage equipment; The operation and maintenance costs of energy cascade utilization equipment; is the response subsidy given to the load aggregator; the expressions of each item are: ； Where: ; is the energy purchase cost of the load aggregator, The energy sales revenue for energy suppliers, is the power purchased from the grid. When it is positive, it means purchasing power, and vice versa, it means selling power to the grid. , Absorbing and emitting power for electrical energy storage; , For the absorption and emission of thermal energy storage; is the price of electricity sold by the grid, For the on-grid electricity price; , , They are the unit output power operation and maintenance prices of electric energy storage, thermal energy storage equipment and energy conversion equipment respectively; Energy Suppliers: The energy supplier determines the internal equipment output according to the electricity and heat prices set by the operator. The optimization goal is to maximize the profit. The objective function can be expressed as: ； Where: To earn revenue from the sale of energy to system operators; for the cost of fuel; Operation and maintenance costs of energy production equipment; The cost of wind curtailment; is the abandoned light cost; the expressions of each item are: ； Where: ; , The electrical and thermal power exported to energy suppliers; , The electricity and heat purchase prices issued by operators; , , , is the cost coefficient; For equipment The unit output power operation and maintenance price; For equipment exist Output power at the moment; , The unit price of abandoned wind and solar power; , The abandoned wind and solar power. In addition, the following constraints must be met: ； Where: , The wind power and photovoltaic power absorbed by the system; , The power generation efficiency and heat generation efficiency of the gas turbine; , Equipment Maximum and minimum output power; , Equipment The landslide rate and climbing rate; Comprehensive Load Aggregator: The integrated load aggregator conducts incentive-based demand response based on the electricity and heat prices set by the operator. The optimization goal is to maximize the residual user satisfaction. Its objective function can be expressed as: ； Where: The residual satisfaction after user demand response; Subsidies given by operators to users after receiving demand response; is the user's energy purchase cost; the expressions of each item are: ； Where: , , , are the user’s preference coefficients for electric energy and medium-temperature thermal energy, respectively; is the actual electrical load power; is the actual medium temperature heat load power; , The electric load that can be shifted and the medium-temperature heat load that can be curtailed are formulated after the load aggregator responds to the demand; , The unit price of subsidies for shiftable electrical loads and curtailable medium-temperature thermal loads; , is the actual steam heat load power and the actual high temperature heat load power; , The electricity price and the highest-grade steam heat price sold by the operator; the actual electricity load and medium-temperature heat load of the user can be expressed as: ； Where: , For fixed electric loads and transferable electric loads; , The fixed medium-temperature heat load and the reducible medium-temperature heat load are the user groups of steam load and high-temperature load. The user groups of steam load and high-temperature load are industrial loads. In order to ensure the uninterrupted supply of industrial heat load, the reducible heat load is not considered. The user groups of medium-temperature load are commercial users and residential users. Their reducible heat load is considered. In addition, the shiftable electric load and the reducible medium-temperature heat load must also meet the following constraints: ； Where: , It can shift the electrical load and reduce the upper limit of the medium temperature heat load. The total amount of load that can be moved in one day.

5. The master-slave game optimization operation method of the regional comprehensive energy system considering the energy cascade utilization according to claim 4 is characterized in that: The constraints of the S2 subject decision model are as follows: Price constraints: The prices set by operators should meet the following constraints: ； Where: Indicates 24 hours a day; , The minimum and maximum prices for thermal energy; is the average electricity selling price; is the average hot selling price; Power Constraints: For the system to operate normally, it is necessary to balance the supply and demand of electricity, heat and cooling, that is, to meet the following constraints: ； Where: is the cooling load power.

6. The master-slave game optimization operation method of regional comprehensive energy system considering energy cascade utilization according to claim 5 is characterized in that: In the master-slave game equilibrium of S3, the master-slave game model can be expressed as: ； The model covers the three elements of the game: game subjects, decision variables and benefit functions; among them, the game subjects are mainly operators, energy suppliers and load aggregators; the decision variables are the purchase and sale prices of electricity and heat set by the operators. , the electric heating power output by the energy supplier , the load aggregator can transfer the electric load and reduce the medium temperature heat load in each period ; The benefit function is the objective function of each subject; Based on the electricity and heat prices issued by the leader, the followers make the best strategy and are accepted by the leader. The game reaches the Nash equilibrium, that is, when the following equation is satisfied, there is an equilibrium solution: : 。 7. The master-slave game optimization operation method of regional comprehensive energy system considering energy cascade utilization according to claim 6 is characterized in that: In the S5, the article model is determined according to the objective function of each subject participating in the game, and the genetic algorithm combined with quadratic programming is used to solve the model; wherein, the upper-level operator strategy is solved by genetic algorithm, and the lower-level energy supplier and load aggregator strategy is solved by quadratic programming; the model is solved by simulation using the CPLEX solver of the MATLAB platform.

Images