An optimization method for electrical and thermal integrated energy system

Abstract

The present invention discloses an optimization method for an electric-thermal integrated energy system, which belongs to the field of optimized operation of integrated energy systems, including determining the component structure and each component structure model of the electric-thermal integrated energy system; determining the double-side coupling model of the electric-thermal integrated energy system according to the contained energy conversion equipment; designing an incentive-type integrated demand response implementation framework considering multi-energy coupling according to the market transaction mechanism of traditional incentive-type demand response; analyzing the coupling characteristics and dynamic characteristics between multiple energy sources on the user side, and determining an incentive-type integrated demand response model considering user response characteristics; constructing an optimization model of the electric-thermal integrated energy system with the goal of minimizing the cost of integrated energy service providers according to the comprehensive demand response model and the component structure of the electric-thermal integrated energy system; solving the optimization model and determining the optimization method of integrated energy service providers and users. The present invention can promote wind and solar power consumption and improve energy utilization on the basis of reducing the costs of service providers and users.

Description

Technical Field

[0001] The present invention relates to the field of optimized operation of integrated energy systems, and in particular to an optimization method for an electrical-thermal integrated energy system. Background Art

[0002] In today's world, traditional fossil energy not only pollutes the environment but also has a decreasing stock, so it is very important to develop clean energy such as wind and light. Energy conversion and coupling equipment such as cogeneration units and gas boilers in the integrated energy system are related to the conversion, distribution and effective utilization of energy, and can effectively promote the absorption of wind and light and improve energy utilization. In the context of the integrated energy system, in order to further improve the absorption level of wind and light, achieve energy conservation and emission reduction, and reduce operating costs, studying the optimized operation of the integrated energy system has become an effective way.

[0003] In the optimized operation of the integrated energy system, since the response characteristics of users have a great impact on the economy and safety of the system, the response characteristics of users to various energy sources should be considered when considering the optimized operation. In order to better deal with these problems, it is necessary to describe the energy consumption on the user side in detail. For the park integrated energy system containing electric cold and hot energy, an optimization model considering the response characteristics of multiple energy sources on the demand side is established. The response characteristics of users mainly include the complementary effects between different energy sources in the same period and between different energy sources in different periods. In the same time period, the increase in user electricity will lead to a decrease in the use of heat or cold energy. Similarly, the change in energy use on the user side in the previous period will also affect the choice of energy use in the next period. This model can not only reduce the operating cost of the park integrated energy system, reduce the user's energy purchase cost, and thus improve user satisfaction, but also promote the consumption of distributed energy such as wind and solar, and improve energy utilization.

[0004] On the energy supply side, demand response can be divided into price-based integrated demand response and incentive-based integrated demand response according to regulatory measures. That is, the purpose of changing users' energy consumption behavior is achieved by changing prices or introducing incentives. It is necessary to consider the regulatory measures on the supply side and the response characteristics on the user side in combination. How to effectively use mathematical models to describe the user's response characteristics becomes a difficulty and key.

[0005] Therefore, it is necessary to develop an incentive strategy that takes into account the user response characteristics on the demand side so as to more accurately describe the coupling relationship on the user side and improve the system economy. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an optimization method for an electrical and thermal integrated energy system, which can reduce the operating costs of integrated energy service providers and the energy purchasing costs of users, and promote the consumption of wind and light, providing the best strategy for integrated energy service providers.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] An electrical and thermal integrated energy system optimization method comprises the following steps:

[0009] Step 1, determine the component structure and each component structure model of the electrical and thermal integrated energy system;

[0010] Step 2: Determine the double-side coupling model of the electrical and thermal integrated energy system according to the energy conversion equipment involved;

[0011] Step 3: Based on the market transaction mechanism of traditional incentive-based demand response, design an incentive-based integrated demand response implementation framework that considers multi-energy coupling;

[0012] Step 4: Analyze the coupling characteristics and dynamic characteristics between multiple energy sources on the user side, and determine an incentive-based comprehensive demand response model that takes into account user response characteristics;

[0013] Step 5: Based on the incentive-based integrated demand response model of user response characteristics and the composition structure of the electric-thermal integrated energy system, an optimization model of the electric-thermal integrated energy system is constructed with the goal of minimizing the cost of the integrated energy service provider;

[0014] Step 6, solving the constructed electrical and thermal integrated energy system optimization model to determine the optimization methods for integrated energy service providers and users.

[0015] A further improvement of the technical solution of the present invention is that: in step 1, the electrical and thermal integrated energy system is divided into a supply side and a demand side;

[0016] On the supply side, integrated energy service providers purchase the corresponding energy from external power grids, gas grids and heat grids, and then convert it into energy that users can directly use through energy conversion equipment. The supply side can also access distributed energy and pass on various energy prices to users on the demand side.

[0017] On the demand side, users rely on their own energy conversion equipment to choose the energy use method that suits them best, so that the economy and comfort of users' energy use are optimized. The demand side can transmit its own energy use information to the supply side, and the energy use information includes energy type, time and usage.

[0018] A further improvement of the technical solution of the present invention is that in step 2, the supply side coupling model is:

[0019]

[0020] In the formula, p r and p h They represent the total electrical energy and total thermal energy obtained by users from the integrated energy service provider; E e 、Eg and E h are the electricity, gas and heat energy purchased by the system integrated energy service provider from the superior energy network; η T , and η GB They are transformer conversion efficiency, electric energy output efficiency and thermal energy output efficiency of cogeneration units, and gas boiler conversion efficiency. The heat exchanger conversion efficiency is 1, and there is no heat loss in the heat conversion process. The cogeneration unit operates in a heat-to-electricity mode, that is, the power generation is adjusted according to the heat load. The back-pressure unit has better economic efficiency. and They represent the allocation coefficients of the natural gas resources purchased from the upper energy network to the cogeneration unit and the gas boiler. Since all the purchased natural gas energy is allocated to the cogeneration unit and the gas boiler, Established; p w and p v is the output power of wind power and photovoltaic power connected to the system; Indicates the amount of natural gas purchased and allocated to the cogeneration unit. The amount of natural gas purchased is allocated to the gas boiler, and according to the actual situation, The controllable variables of the integrated energy service provider system are and That is, the optimal operation mode is obtained by controlling the energy distribution ratio of different equipment;

[0021] Among them, the demand side coupling model is:

[0022]

[0023] Where D e , D g and D c Respectively represent the electrical energy, thermal energy and cold energy consumed by the user after passing through the energy conversion equipment; L e and L h They represent the electric energy and thermal energy required by the user side under the most comfortable energy consumption mode, that is, when the user's energy consumption is met, p e =L e and p h =L h ; η EHP , η HE , η AC and η AF They represent the energy conversion efficiency of electric heat pump, heat exchanger, central air conditioner and absorption chiller respectively; and They represent the electric energy directly consumed by users, the total electric energy of EHP units and central air conditioners when users are most comfortable. eThe distribution coefficient in ; and are the total thermal loads L of the heat exchanger and absorption chiller when the user side comfort is the highest. h The distribution coefficient in .

[0024] The further improvement of the technical solution of the present invention is that: in step 3, the incentive-based comprehensive demand response implementation architecture is divided into three main bodies and two stages;

[0025] The first stage involves multi-energy trading markets and integrated energy service providers;

[0026] The subjects of the second phase are comprehensive energy service providers and users;

[0027] The two-stage execution process is as follows:

[0028] The first stage is the bidding stage. First, the energy dispatchers of electricity, natural gas, and heat networks will predict the future power production and use, and then send the information of excess energy that cannot be absorbed or shortage to the multi-energy trading market; the goal of the multi-energy trading market is to balance the supply and demand of various energy sources and realize energy market clearing. To achieve this goal, the multi-energy trading market will send energy imbalance information to the integrated energy service provider. The integrated energy service provider will formulate incentives to enable its users to participate in demand response to achieve the clearing goal. At the same time, the integrated energy service provider will report the adjustment plan to the multi-energy trading market; after receiving the adjustment plan from the integrated energy service provider, the multi-energy trading market will select the most appropriate one or more integrated energy service providers to implement demand response with the goal of minimizing system operation costs and market clearing. If the integrated energy service provider fails to complete the rated demand response plan, it will be fined;

[0029] The second stage is the implementation stage. After selecting the appropriate demand response strategy and the integrated energy service provider for implementation in the multi-energy trading market, the integrated energy service provider will formulate differentiated incentive subsidy prices by energy and time period according to the demand response volume it needs to complete, and complete the required different types of energy by adjusting the operating parameters of energy production and conversion equipment, while also reducing operating costs; after receiving the differentiated incentive price, the user will change his or her energy demand by using different household equipment with the goal of higher comfort and lower energy purchase costs; after the user has participated in the comprehensive demand response, the integrated energy service provider will give the user incentive subsidies according to the agreement;

[0030] The three main objectives are:

[0031] Multi-energy trading market: The optimization goal of the multi-energy trading market is to minimize the system operating cost on the basis of completing the energy power balance. The operating cost is the response target completion reward settled to the integrated energy service provider minus the penalty cost of the integrated energy service provider for not completing the response target. The goal is achieved by selecting the optimal control plan and cooperating with multiple different integrated energy service providers.

[0032] Integrated energy service providers: The optimization goal of integrated energy service providers is to minimize their own costs or maximize profits. Their own costs include the rewards for the response targets completed from the multi-energy trading market, the penalty costs for the response targets not completed, and the incentive costs of subsidies to users.

[0033] User: The user's optimization goal is to minimize his or her own energy usage cost. The usage cost is the user's lost comfort cost and energy purchase cost minus the energy subsidy income obtained from the integrated energy service provider.

[0034] A further improvement of the technical solution of the present invention is that in step 4, the incentive-based comprehensive demand response model considering the user response characteristics is:

[0035]

[0036] In the formula, r′ i.k and The value of can be positive or negative. When it is positive, it indicates that the corresponding energy type is a reduction response, and when it is negative, it indicates that the corresponding energy type is an absorption response; s MEA,k It can indicate the type of comprehensive demand response. When it is a reduction response, its value is 1, and when it is an absorption response, its value is -1; s i,k =[s e,i,k ,s h,i,k ,s i,k ] T It can indicate the energy change trend of the user. When its value is 1, it indicates that the user's usage of this type of load is decreasing. When its value is -1, it indicates that the usage of this type of energy load is increasing.

[0037] A further improvement of the technical solution of the present invention is that in step 5, when the multi-energy trading market determines to select a comprehensive energy service provider to implement comprehensive demand response, the power situation of multiple energy sources in the system that need to be balanced will be sent to the comprehensive energy service provider, and then the comprehensive energy service provider will complete the response target by adjusting the operating parameters of the energy coupling equipment and formulating differentiated incentive prices. Its goal is to minimize the total operating cost of the comprehensive energy service provider. The optimization model of the electrical and thermal comprehensive energy system is:

[0038]

[0039] In the formula, C IESPIt represents the total input cost of the integrated energy service provider; is the incentive cost given by the integrated energy service provider to users during period t; Represents the operating cost of the energy storage device; Represents the operating cost of energy conversion equipment.

[0040] A further improvement of the technical solution of the present invention is that: wherein the total operating cost of the integrated energy service provider includes incentive costs, energy storage equipment operating costs, and energy conversion equipment operating costs;

[0041] The total incentive cost given by the integrated energy service provider to the user is calculated based on the user's actual response amount, and its value is related to the user's actual response amount and the unit incentive price; the total incentive cost is expressed as:

[0042]

[0043] In the formula, p i,j,t represents the unit incentive price of the j-th energy source set by the integrated energy service provider for user i in period t; ξ i,j,t represents the actual response power of the jth energy source in the i-th user during period t; Indicates the comprehensive demand response type of the j-th energy source in period t. When it is a reduction type IDR, It is 1, and its value is -1 when it is a consumption type IDR; N is the number of users; it is stipulated here that j is 1, 2, and 3 when it represents electric energy, thermal energy, and gas energy respectively;

[0044] The electrical and thermal integrated energy system contains a large number of energy storage devices. Its operating costs include depreciation costs and maintenance costs. Its operating costs are related to the characteristics of the equipment itself and the output power. Therefore, it is equivalent to a quadratic function of the charging and discharging power. The operating cost of the energy storage equipment is expressed as:

[0045]

[0046] In the formula, α j is the cost coefficient of the j-th energy storage device; The response power provided by the j-th energy storage device to the user side during period t;

[0047] Energy conversion equipment includes electric boilers, gas turbines and cogeneration units; the operating cost of energy conversion equipment is expressed as:

[0048]

[0049] In the formula, is the baseline load of the j-th energy source at time t, that is, the energy load before the user participates in demand response; is the actual response demand of the jth energy in period t, that is, the demand target allocated by the multi-energy trading market to the integrated energy service provider; μ EB , μ GT , μ CHP They represent the unit power operating prices of energy conversion equipment electric boilers, gas turbines and cogeneration units respectively.

[0050] A further improvement of the technical solution of the present invention is that the constraint conditions of the optimization model of the electrical and thermal integrated energy system are:

[0051] In order to extend the service life of energy storage equipment, the charging and discharging power of energy storage should also meet the corresponding power limit:

[0052]

[0053] In the formula, represents the stock of the jth type of energy storage device in period t; represents the initial capacity of the j-th energy storage device; η ES Indicates the charge-discharge conversion coefficient of energy storage, which is 0.9 in the charging state and 1.1 in the discharging state; represents the maximum allowable capacity of the j-th energy storage device; v min and v max They represent the minimum energy state and maximum energy state of the energy storage device, and take values ​​of 0.1 and 0.9 respectively; Formula (17) indicates that the state of the energy storage device remains unchanged after the entire response cycle ends;

[0054] The incentive price issued by the integrated energy service provider to users must also meet certain constraints. If the price is too high, no profit can be obtained. If the price is too low, more users cannot participate in demand response. It is necessary to select a suitable price to maximize the profit on the basis of achieving the response target. The constraints are expressed as follows:

[0055]

[0056] in, Subsidized prices provided for multi-energy trading markets.

[0057] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0058] 1. When optimizing the integrated energy system, the present invention aims to minimize the cost for integrated energy service providers and users, and also takes into account the coexistence of absorption-type demand response and reduction-type demand response, and can adapt to complex scenarios.

[0059] 2. The present invention can reduce the operating costs of integrated energy service providers and the energy purchasing costs of users, and promote the consumption of wind and solar power, providing the best strategy for integrated energy service providers.

[0060] 3. The present invention can reduce the costs of integrated energy service providers and users, while improving the wind and light absorption levels. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a flow chart of the optimization method of the electrical and thermal integrated energy system of the present invention;

[0062] Figure 2 It is a schematic diagram of the structure of the electrical and thermal integrated energy system of the present invention. DETAILED DESCRIPTION

[0063] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] The English name of integrated energy service provider is integrated energy service provider, abbreviated as IESP.

[0065] like Figure 1 As shown, a method for optimizing an electrical and thermal integrated energy system comprises the following steps:

[0066] Step 1, determine the component structure and each component structure model of the electrical and thermal integrated energy system;

[0067] The integrated energy system is divided into the supply side and the demand side. On the supply side, the integrated energy service provider purchases the corresponding energy from the external power grid, gas grid and heat grid, and then converts it into energy that can be directly used by users through energy conversion equipment such as transformers, cogeneration units, gas boilers and heat exchangers. In addition, the supply side can access distributed energy such as photovoltaics and wind turbines, and the supply side transmits various energy prices to users on the demand side. On the demand side, users can rely on some energy conversion equipment they own to choose the most suitable energy use method for themselves. For example, they can use electric heat pumps, electric refrigerators, heat exchangers, absorption refrigerators and other equipment to change the energy use situation, so that the user's energy economy and comfort are optimized. The demand side can transmit its own energy use information to the supply side, including energy type, time and usage. In short, the energy supply side encourages users to adjust their energy use through price signals to reduce operating costs, and the load side reduces energy purchase costs by changing the type and quantity of energy use through conversion equipment. The combination of the two realizes coordinated operation and joint optimization of both supply and demand sides, such as Figure 2 shown.

[0068] The key equipment models of the electrical and thermal integrated energy system are as follows:

[0069] 1) CHP unit

[0070] The CHP unit consists of a gas turbine and a waste heat collection device that absorbs natural gas and converts it into electricity and heat.

[0071]

[0072] In the formula, G 1,t is the energy corresponding to the natural gas input into the cogeneration unit at time t; η gh The conversion efficiency of the combined heat and power unit to produce heat energy; H CHP,t is the heat energy produced by the cogeneration unit at time t; η ge The conversion efficiency of the combined heat and power unit to produce electricity; E CHP,t is the electricity produced by the cogeneration unit at time t.

[0073] 2) Gas boilers can convert natural gas energy into thermal energy to supply users with thermal load. Specific equipment of this type includes gas-fired water boilers, gas-fired hot water boilers, gas-fired steam boilers, etc.

[0074] H GB,t =G 2,t η h (2)

[0075] Where: H GB,t Represents the heat energy produced by the gas boiler at time t; η h Represents thermal energy conversion efficiency; G 2,t Represents the energy of natural gas input to the gas boiler at time t.

[0076] 3) Electric refrigerators can convert electrical energy into cold energy for users.

[0077] C ER,t =E t η ec (3)

[0078] In the formula, C ER,t represents the cold energy produced at time t; E t The electrical energy input to the electric refrigeration equipment; η ec is the cold energy conversion rate.

[0079] 4) Absorption chillers can convert the heat energy generated by the CHP unit into cold energy, relying on the action of the absorber-generator group to complete the refrigeration cycle. The main types are ammonia absorption chillers and lithium bromide absorption chillers.

[0080] C AC,t =H t η hc (4)

[0081] Where: C AC,t represents the cooling energy produced by the absorption refrigerator at time t; H t represents the heat energy input to the absorption refrigerator at time t, η hc Indicates the energy conversion efficiency of the device.

[0082] 5) Batteries can store excess electricity produced by the power grid or release electricity for users when electricity is scarce.

[0083]

[0084] Where W t represents the electrical energy stored in the battery at time t; w t-1 E represents the electrical energy originally present in the battery in the period before time t; c,t Indicates the charging power of the battery when storing energy, η c Indicates the energy conversion efficiency when the battery is charged; E d,t It represents the discharge power of the battery when it releases energy at time t, η d Indicates the energy conversion efficiency of the battery when discharging; θ is the percentage of energy consumed by the battery itself when storing energy; W max and W min The maximum and minimum values ​​of the energy stored in the battery depend on the physical characteristics of the device and the ambient temperature. Due to the influence of the energy storage material of the battery itself, different energy storage materials have very different working power limits.

[0085]

[0086] Where: E c,max and E c,min Respectively represent the maximum and minimum values ​​of the battery charging power; E d,max and E d,min Respectively represent the maximum and minimum values ​​of battery discharge power; I c,t and I d,t They represent the state variables of the battery when storing and releasing electrical energy at time t respectively.

[0087] Step 2: Determine the double-side coupling model of the electrical and thermal integrated energy system according to the energy conversion equipment involved;

[0088] According to the structure diagram of the electrical-thermal integrated energy system, the double-sided coupling model of the electrical-thermal integrated energy system is determined.

[0089] Among them, the supply-side coupling model is:

[0090]

[0091] In the formula, pe and p h They represent the total electrical energy and total thermal energy obtained by users from the integrated energy service provider; E e 、E g and E h are the electricity, gas and heat energy purchased by the system integrated energy service provider from the superior energy network; η T , and η GB They are transformer conversion efficiency, electric energy output efficiency and thermal energy output efficiency of cogeneration units, and gas boiler conversion efficiency. The heat exchanger conversion efficiency is 1, and there is no heat loss in the heat conversion process. The cogeneration unit operates in a heat-to-electricity mode, that is, the power generation is adjusted according to the heat load. The back-pressure unit has better economic efficiency. and They represent the allocation coefficients of the natural gas resources purchased from the upper energy network to the cogeneration unit and the gas boiler. Since all the purchased natural gas energy is allocated to the cogeneration unit and the gas boiler, Established; p w and p v is the output power of wind power and photovoltaic power connected to the system; Indicates the amount of natural gas purchased and allocated to the cogeneration unit. The amount of natural gas purchased is allocated to the gas boiler, and according to the actual situation, The controllable variables of the integrated energy service provider system are and That is, the optimal operation mode is obtained by controlling the energy distribution ratio of different equipment.

[0092] Among them, the demand side coupling model is:

[0093]

[0094] Where D e , D h and D c Respectively represent the electrical energy, thermal energy and cold energy consumed by the user after passing through the energy conversion equipment; L e and L h They represent the electric energy and thermal energy required by the user side under the most comfortable energy consumption mode, that is, when the user's energy consumption is met, p e =L e and p h =L h ; η EHP , η HE , η AC and η AF They represent the energy conversion efficiency of electric heat pump, heat exchanger, central air conditioner and absorption chiller respectively; and They represent the electric energy directly consumed by users, the total electric energy of EHP units and central air conditioners when users are most comfortable. e The distribution coefficient in ; and are the total thermal loads L of the heat exchanger and absorption chiller when the user side comfort is the highest. h Considering the practical significance, since the total electrical energy and total thermal energy are all allocated to these devices, these five coefficients satisfy formula (8), and users can obtain the optimal allocation by controlling these coefficients.

[0095] Step 3: Based on the market transaction mechanism of traditional incentive-based demand response, design an incentive-based integrated demand response implementation framework that considers multi-energy coupling;

[0096] The implementation framework of incentive-based integrated demand response is divided into three main bodies and two stages. The main bodies of the first stage are the multi-energy trading market and integrated energy service providers (IESP), and the main bodies of the second stage are integrated energy service providers (IESP) and users.

[0097] The two-stage execution process is as follows:

[0098] The first stage is the bidding stage. First, the energy dispatchers of electricity, natural gas, and heat networks will predict the future power production and use, and then send the information of excess energy that cannot be absorbed or is in short supply to the multi-energy trading market. The goal of the multi-energy trading market is to balance the supply and demand of various energy sources and achieve energy market clearing. To achieve this goal, the multi-energy trading market sends energy imbalance information to integrated energy service providers. Integrated energy service providers can achieve the clearing goal by formulating incentives to enable their users to participate in demand response. At the same time, integrated energy service providers will report the adjustment plan to the multi-energy trading market. The plan consists of the following parts: the minimum compensation price per unit of energy, the response price elasticity, and the maximum response amount of each energy. After receiving the adjustment plan from the integrated energy service provider, the multi-energy trading market selects the most suitable one or more integrated energy service providers to implement demand response with the goal of minimizing system operation costs and market clearing. If the integrated energy service provider fails to complete the rated demand response plan, it will be fined.

[0099] The second stage is the implementation stage. After selecting the appropriate demand response strategy and the integrated energy service provider for implementation in the multi-energy trading market, the integrated energy service provider will formulate differentiated incentive subsidy prices by energy and time period according to the demand response volume it needs to complete, and complete the required different types of energy by adjusting the operating parameters of energy production and conversion equipment, while also reducing operating costs; after receiving the differentiated incentive price, the user will change his or her energy demand by using different household equipment with the goal of higher comfort and lower energy purchase costs. After the user has participated in the comprehensive demand response, the integrated energy service provider will give the user incentive subsidies according to the agreement.

[0100] The three main objectives are:

[0101] Multi-energy trading market: The optimization goal of the multi-energy trading market is to minimize the system operating cost on the basis of completing the energy power balance. The operating cost is the response target completion reward settled to the integrated energy service provider minus the penalty cost of the integrated energy service provider for not completing the response target. The goal can be achieved by selecting the optimal control plan and cooperating with multiple different integrated energy service providers.

[0102] Integrated energy service providers: The optimization goal of integrated energy service providers is to minimize their own costs or maximize profits. The costs include the rewards for the response targets completed from the multi-energy trading market, the penalty costs for the response targets not completed, and the incentive costs subsidized to users.

[0103] User: The user's optimization goal is to minimize his or her own energy usage cost, which is the user's lost comfort cost and energy purchase cost minus the energy subsidy income obtained from the integrated energy service provider.

[0104] Step 4: Analyze the coupling characteristics and dynamic characteristics between multiple energy sources on the user side, and determine an incentive-based comprehensive demand response model that takes into account user response characteristics;

[0105] Analysis of demand-side coupling characteristics of integrated energy systems including electricity, gas and heat:

[0106]

[0107] In the formula, the matrix Q i,k is the coupling coefficient matrix between the electrical and thermal energy sources of user i in time period k, in which the elements represent the coupling response degree between the three energy sources of electricity and heat. The diagonal elements in the matrix represent the coupling effect between the same energy sources, and their values ​​are always 1. The non-diagonal elements represent the coupling effect degree of different energy sources, and their values ​​are all positive. A positive value indicates that when the change trends between the two energy sources are the same, that is, the same increase or decrease will reduce the response ability of each other, and different change trends, that is, the increase in the usage of one energy and the decrease in the usage of the other energy will increase the response ability of each other.

[0108] Analysis of dynamic characteristics of demand side of integrated energy system including electricity, gas and heat:

[0109]

[0110] In the formula, r′ i,k =[r′ ei,k ,r′ hi,k ,r′ gi,k ] T It indicates the actual response quantity of the three energy sources of electricity, heat and gas of the users; Indicates the active response of the user's three energy sources: electricity, heating and gas; φ i,t,k It represents the impact of the response trend in period i on the response trend in period k.

[0111] The dynamic characteristics of users on a time scale are mainly reflected in the following two aspects:

[0112] First, according to the description of the first constraint, the response change in the previous period will affect the response potential of users in the later period. Second, according to the description of the third constraint, because the actual response of users in the current period will be affected by the response in the previous period, the active response in the current period is not equal to the actual response. The function φ in the above formula i,t,k for:

[0113]

[0114] Where: i,t,k =[ω e,i,t,k ,ω h,i,t,k ,ω g,i,t,k ] T Indicates the degree of influence of the response strategy in period t on the response strategy in period `.

[0115] An incentive-based integrated demand response (IDR) model considering user response characteristics is established.

[0116]

[0117] In the formula, r′ i.k and The value of may be positive or negative. When it is positive, it indicates that the corresponding energy type is a reduction response, and when it is negative, it indicates that the corresponding energy type is an absorption response; s MEA,k It can indicate the type of comprehensive demand response. When it is a reduction response, its value is 1, and when it is an absorption response, its value is -1; s i,k =[s e,i,k ,s h,i,k ,s i,k ] TIt can indicate the energy change trend of the user. When its value is 1, it indicates that the user's usage of this type of load is decreasing. When its value is -1, it indicates that the usage of this type of energy load is increasing.

[0118] Step 5: Based on the incentive-based integrated demand response model of user response characteristics and the composition structure of the electric-thermal integrated energy system, an optimization model of the electric-thermal integrated energy system is established with the goal of minimizing the cost of the integrated energy service provider;

[0119] When the multi-energy trading market determines to select a comprehensive energy service provider to implement comprehensive demand response, the power situation of multiple energy sources that need to be balanced in the system will be sent to the comprehensive energy service provider. The comprehensive energy service provider then completes the response target by adjusting the operating parameters of the energy coupling equipment and formulating differentiated incentive prices. The goal is to minimize the total operating cost of the comprehensive energy service provider. The objective function (optimization model of the electrical and thermal comprehensive energy system) is:

[0120]

[0121] In the formula, C IESP It represents the total input cost of the integrated energy service provider; is the incentive cost given by the integrated energy service provider to users during period t; Represents the operating cost of the energy storage device; Represents the operating cost of energy conversion equipment.

[0122] The total operating costs of integrated energy service providers include incentive costs, energy storage equipment operating costs, and energy conversion equipment operating costs.

[0123] The total incentive cost given by the integrated energy service provider to the user is calculated based on the user's actual response amount, and its value is related to the user's actual response amount and the unit incentive price. The total incentive cost is expressed as:

[0124]

[0125] In the formula, p i,j,t represents the unit incentive price of the j-th energy source set by the integrated energy service provider for user i in period t; ξ i,j,t represents the actual response power of the jth energy source in the i-th user during period t; Indicates the comprehensive demand response type of the j-th energy source in period t. When it is a reduction type IDR, It is 1, and its value is -1 for the consumption type IDR; N is the number of users. Here, it is stipulated that when j is 1, 2, and 3, it represents electric energy, thermal energy, and gas energy respectively.

[0126] The electrical and thermal integrated energy system contains a large number of energy storage devices, such as thermal energy storage devices, electrical energy storage devices, etc. Its operating costs include depreciation costs and maintenance costs. Its operating costs are related to the characteristics of the equipment itself and the output power. Therefore, it can be equivalent to a quadratic function of the charging and discharging power. The operating cost of the energy storage device is expressed as:

[0127]

[0128] In the formula, α j is the cost coefficient of the j-th energy storage device; It is the response power provided by the j-th energy storage device to the user side in period t.

[0129] Energy conversion equipment includes electric boilers, gas turbines and combined heat and power units. The operating cost of energy conversion equipment is expressed as:

[0130]

[0131] In the formula, is the baseline load of the j-th energy source at time t, that is, the energy load before the user participates in demand response; is the actual response demand of the jth energy in period t, that is, the demand target allocated by the multi-energy trading market to the integrated energy service provider; μ EB , μ GT , μ CHP They represent the unit power operating prices of energy conversion equipment electric boilers, gas turbines and cogeneration units respectively.

[0132] The constraints of the comprehensive energy service provider cost model are:

[0133] In order to extend the service life of the energy storage equipment, the charging and discharging power of the energy storage should also meet the corresponding power limit.

[0134]

[0135] In the formula, represents the stock of the jth type of energy storage device in period t; represents the initial capacity of the j-th energy storage device; η ES Indicates the charge-discharge conversion coefficient of energy storage, which is 0.9 in the charging state and 1.1 in the discharging state; represents the maximum allowable capacity of the j-th energy storage device; v min and v max They represent the minimum energy state and maximum energy state of the energy storage device, and take values ​​of 0.1 and 0.9 respectively. Formula (17) indicates that the state of the energy storage device remains unchanged after the entire response cycle ends.

[0136] The incentive price issued by the integrated energy service provider to users must also meet certain constraints. If the price is too high, no profit can be obtained. If the price is too low, more users cannot participate in demand response. It is necessary to select a suitable price to maximize the profit on the basis of achieving the response target. The constraints are expressed as follows:

[0137]

[0138] In the formula, Subsidized prices provided for multi-energy trading markets.

[0139] Step 6: Solve the optimization model of the electrical and thermal integrated energy system that takes into account the user response characteristics and determine the optimization methods for energy service providers and users.

[0140] The established electric-thermal integrated energy system optimization model is a two-layer optimization model. The upper layer is the integrated energy service provider, which needs to provide incentive prices to users. The optimization goal is to minimize the operating cost, and it belongs to the leader; the lower layer is the user, who determines the response amount of its own multiple energy sources according to the incentive price provided by the integrated energy service provider and returns this information to the integrated energy service provider. Its optimization goal is to minimize the energy cost, and it belongs to the follower. The information exchange process between the above two can be regarded as a Stackelberg game model with one master and multiple followers. It is necessary to prove the existence of the only optimal equilibrium solution. The proof process is as follows.

[0141] 1) According to the established incentive-based integrated demand response model considering user response characteristics, the strategy of the upper-level integrated energy service provider needs to satisfy equations (17)-(18), and the strategy set of each IDR participant is a non-empty compact convex set;

[0142] 2) Prove that when the strategy of the upper leader is given, all lower levels have only one optimal solution.

[0143] Find the user benefit objective function about ξ i,j,t The first-order partial derivative of , we can get:

[0144]

[0145] Setting the first-order partial derivative equal to 0, we can get

[0146]

[0147] Further seeking the second-order partial derivative yields:

[0148]

[0149] Since the user's response willingness θ i,j,tis a positive value, and the second-order partial derivative is always negative, indicating that the user objective function is a strict concave function, so there must be a maximum value. Therefore, when the integrated energy service provider issues an incentive price to the user, each user has a unique optimal solution.

[0150] The above two points can prove that the IDR optimization incentive strategy proposed in the present invention has a unique Stackelberg equilibrium solution.

[0151] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for optimizing an electrical and thermal integrated energy system, characterized in that: The following steps are involved: Step 1, determine the component structure and each component structure model of the electrical and thermal integrated energy system; Step 2: Determine the double-side coupling model of the electrical and thermal integrated energy system according to the energy conversion equipment involved; Step 3: Based on the market transaction mechanism of traditional incentive-based demand response, design an incentive-based integrated demand response implementation framework that considers multi-energy coupling; Step 4: Analyze the coupling characteristics and dynamic characteristics between multiple energy sources on the user side, and determine an incentive-based comprehensive demand response model that takes into account user response characteristics; The incentive-based comprehensive demand response model considering user response characteristics is: In the formula, r′ i，k and The value of can be positive or negative. When it is positive, it indicates that the corresponding energy type is a reduction response, and when it is negative, it indicates that the corresponding energy type is an absorption response; s MEA，k It can indicate the type of comprehensive demand response. When it is a reduction response, its value is 1, and when it is an absorption response, its value is -1; s i，k =[s e，i，k ,s h，i，k ,s i，k ] T It can indicate the energy change trend of the user. When the value is 1, it means that the user's load usage of this type of load is reduced, and when the value is -1, it means that the energy load usage of this type of energy load is increased. Step 5: Based on the incentive-based integrated demand response model of user response characteristics and the composition structure of the electric-thermal integrated energy system, an optimization model of the electric-thermal integrated energy system is constructed with the goal of minimizing the cost of the integrated energy service provider; When the multi-energy trading market determines to select a comprehensive energy service provider to implement comprehensive demand response, the power situation of multiple energy sources that need to be balanced in the system will be sent to the comprehensive energy service provider. The comprehensive energy service provider will then complete the response target by adjusting the operating parameters of the energy coupling equipment and formulating differentiated incentive prices. Its goal is to minimize the total operating cost of the comprehensive energy service provider. The optimization model of the electrical and thermal comprehensive energy system is: In the formula, C IESP It represents the total input cost of the integrated energy service provider; is the incentive cost given by the integrated energy service provider to users during period t; Represents the operating cost of the energy storage device; represents the operating cost of the energy conversion equipment; Step 6, solving the constructed electrical and thermal integrated energy system optimization model to determine the optimization methods for integrated energy service providers and users.

2. The method for optimizing an electrical and thermal integrated energy system according to claim 1, characterized in that: In step 1, the electrical and thermal integrated energy system is divided into a supply side and a demand side; On the supply side, integrated energy service providers purchase the corresponding energy from external power grids, gas grids and heat grids, and then convert it into energy that users can directly use through energy conversion equipment. The supply side can also access distributed energy and pass on various energy prices to users on the demand side. On the demand side, users rely on their own energy conversion equipment to choose the energy use method that suits them best, so that the economy and comfort of users' energy use are optimized. The demand side can transmit its own energy use information to the supply side, and the energy use information includes energy type, time and usage.

3. The method for optimizing an electrical and thermal integrated energy system according to claim 2, characterized in that: In step 2, the supply-side coupling model is: In the formula, p e and p h They represent the total electrical energy and total thermal energy obtained by users from the integrated energy service provider; E e 、E g and E h They are respectively the electricity, gas and heat energy purchased by the system integrated energy service provider from the superior energy network; η T , and η GB They are transformer conversion efficiency, electric energy output efficiency and thermal energy output efficiency of cogeneration units, and gas boiler conversion efficiency. The heat exchanger conversion efficiency is 1, and there is no heat loss in the heat conversion process. The cogeneration unit operates in a heat-to-electricity mode, that is, the power generation is adjusted according to the heat load. The back-pressure unit has better economic efficiency. and They represent the allocation coefficients of the natural gas resources purchased from the upper energy network to the cogeneration unit and the gas boiler. Since all the purchased natural gas energy is allocated to the cogeneration unit and the gas boiler, Established; p w and p v is the output power of wind power and photovoltaic power connected to the system; Indicates the amount of natural gas purchased and allocated to the cogeneration unit. The amount of natural gas purchased is allocated to the gas boiler, and according to the actual situation, The controllable variables of the integrated energy service provider system are and That is, the optimal operation mode is obtained by controlling the energy distribution ratio of different equipment; Among them, the demand side coupling model is: Where D e , D h and D c Respectively represent the electrical energy, thermal energy and cold energy consumed by the user after passing through the energy conversion equipment; L e and L h They represent the electric energy and thermal energy required by the user side under the most comfortable energy consumption mode, that is, when the user's energy consumption is met, p e =L e and p h =L h ; η EHP , η HE , η AC and η AF They represent the energy conversion efficiency of electric heat pump, heat exchanger, central air conditioner and absorption chiller respectively; and They represent the electric energy directly consumed by users, the total electric energy of EHP units and central air conditioners when users are most comfortable. e The distribution coefficient in ; and are the total thermal loads L of the heat exchanger and absorption chiller when the user side comfort is the highest. h The distribution coefficient in .

4. The method for optimizing an electrical and thermal integrated energy system according to claim 1, characterized in that: In step 3, the incentive-based integrated demand response implementation framework is divided into three main bodies and two stages; The first stage involves multi-energy trading markets and integrated energy service providers; The subjects of the second phase are comprehensive energy service providers and users; The two-stage execution process is as follows: The first stage is the bidding stage. First, the energy dispatchers of electricity, natural gas, and heat networks will predict the future power production and use, and then send the information of excess energy that cannot be absorbed or shortage to the multi-energy trading market; the goal of the multi-energy trading market is to balance the supply and demand of various energy sources and realize energy market clearing. To achieve this goal, the multi-energy trading market will send energy imbalance information to the integrated energy service provider. The integrated energy service provider will formulate incentives to enable its users to participate in demand response to achieve the clearing goal. At the same time, the integrated energy service provider will report the adjustment plan to the multi-energy trading market; after receiving the adjustment plan from the integrated energy service provider, the multi-energy trading market will select the most appropriate one or more integrated energy service providers to implement demand response with the goal of minimizing system operation costs and market clearing. If the integrated energy service provider fails to complete the rated demand response plan, it will be fined; The second stage is the implementation stage. After selecting the appropriate demand response strategy and the integrated energy service provider for implementation in the multi-energy trading market, the integrated energy service provider will formulate differentiated incentive subsidy prices by energy and time period according to the demand response volume it needs to complete, and complete the required different types of energy by adjusting the operating parameters of energy production and conversion equipment, while also reducing operating costs; after receiving the differentiated incentive price, the user will change his or her energy demand by using different household equipment with the goal of higher comfort and lower energy purchase costs; after the user has participated in the comprehensive demand response, the integrated energy service provider will give the user incentive subsidies according to the agreement; The three main objectives are: Multi-energy trading market: The optimization goal of the multi-energy trading market is to minimize the system operating cost on the basis of completing the energy power balance. The operating cost is the response target completion reward settled to the integrated energy service provider minus the penalty cost of the integrated energy service provider for not completing the response target. The goal is achieved by selecting the optimal control plan and cooperating with multiple different integrated energy service providers. Integrated energy service providers: The optimization goal of integrated energy service providers is to minimize their own costs or maximize profits. Their own costs include the rewards for the response targets completed from the multi-energy trading market, the penalty costs for the response targets not completed, and the incentive costs of subsidies to users. User: The user's optimization goal is to minimize his or her own energy usage cost. The usage cost is the user's lost comfort cost and energy purchase cost minus the energy subsidy income obtained from the integrated energy service provider.

5. The method for optimizing an electrical and thermal integrated energy system according to claim 1, characterized in that: The total operating cost of the integrated energy service provider includes incentive costs, energy storage equipment operating costs, and energy conversion equipment operating costs; The total incentive cost given by the integrated energy service provider to the user is calculated based on the user's actual response amount, and its value is related to the user's actual response amount and the unit incentive price; the total incentive cost is expressed as: In the formula, p i，j，t represents the unit incentive price of the j-th energy source set by the integrated energy service provider for user i in period t; ξ i，j，t represents the actual response power of the jth energy source in the i-th user during period t; Indicates the comprehensive demand response type of the j-th energy source in period t. When it is a reduction type IDR, It is 1, and its value is -1 when it is a consumption type IDR; N is the number of users; it is stipulated here that j is 1, 2, and 3 when it represents electric energy, thermal energy, and gas energy respectively; The electrical and thermal integrated energy system contains a large number of energy storage devices. Its operating costs include depreciation costs and maintenance costs. Its operating costs are related to the characteristics of the equipment itself and the output power. Therefore, it is equivalent to a quadratic function of the charging and discharging power. The operating cost of the energy storage equipment is expressed as: In the formula, a j is the cost coefficient of the j-th energy storage device; The response power provided by the j-th energy storage device to the user side during period t; Energy conversion equipment includes electric boilers, gas turbines and cogeneration units; the operating cost of energy conversion equipment is expressed as: In the formula, is the baseline load of the j-th energy source at time t, that is, the energy load before the user participates in demand response; is the actual response demand of the jth energy in period t, that is, the demand target allocated by the multi-energy trading market to the integrated energy service provider; μ EB , μ GT , μ CHP They represent the unit power operating prices of energy conversion equipment electric boilers, gas turbines and cogeneration units respectively.

6. The method for optimizing an electrical and thermal integrated energy system according to claim 1, characterized in that: The constraints of the optimization model of the electrical and thermal integrated energy system are: In order to extend the service life of energy storage equipment, the charging and discharging power of energy storage should also meet the corresponding power limit: In the formula, represents the stock of the jth type of energy storage device in period t; represents the initial capacity of the j-th energy storage device; η ES Indicates the charge-discharge conversion coefficient of energy storage, which is 0.9 in the charging state and 1.1 in the discharging state; represents the maximum allowable capacity of the j-th energy storage device; v min and v max They represent the minimum energy state and maximum energy state of the energy storage device, and take values ​​of 0.1 and 0.9 respectively; Formula (17) indicates that the state of the energy storage device remains unchanged after the entire response cycle ends; The incentive price issued by the integrated energy service provider to users must also meet certain constraints. If the price is too high, no profit can be obtained. If the price is too low, more users cannot participate in demand response. It is necessary to select a suitable price to maximize the profit on the basis of achieving the response target. The constraints are expressed as follows: in, Subsidized prices provided for multi-energy trading markets.

Images