Hybrid energy storage optimization method and device considering fused salt heat storage coupling thermal power generating unit

Abstract

The invention relates to a hybrid energy storage optimization method and device considering a fused salt heat storage coupling thermal power generating unit, and the method comprises the steps: analyzing the basic structure and energy flow relation of the fused salt heat storage coupling thermal power generating unit, and carrying out the transformation system division of the fused salt heat storage coupling thermal power generating unit; analyzing energy flow of each device of the fused salt heat storage coupling thermal power generating unit transformation system, and constructing an energy balance model and constraint conditions; building a corresponding mathematical model based on the energy balance model of each device; establishing a double-layer optimization configuration model of the corresponding hybrid energy storage system; solving the mathematical model and the double-layer optimization configuration model; according to the method, a mathematical model corresponding to molten salt heat storage coupled thermal power generating unit transformation system operation analysis is established based on the internal energy flow relation of molten salt heat storage and thermal power generating unit deep coupling, the electrochemical energy storage capacity and the molten salt heat storage capacity can be reasonably optimized through a model calculation result, multi-energy complementation of different types of energy is achieved, and the energy efficiency is improved. The system flexible adjustment capability is improved, and the system operation cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of energy system configuration, and in particular to a hybrid energy storage optimization method and device considering molten salt heat storage coupled with thermal power units. Background Art

[0002] With the large-scale development and utilization of the Shagohuang New Energy Base, the problem of new energy consumption is imminent, and higher requirements are placed on the flexible adjustment of resources in the power system. The energy storage system has the characteristics of energy time shifting, rapid response and flexible layout, which can effectively improve the regulation capacity of the power system and is a key technology to support the power transmission of the Shagohuang New Energy Base. The output of wind and solar power is characterized by randomness and volatility, and the difficulty of intraday, medium-term and long-term balance of the system increases. A single energy storage technology is difficult to meet the requirements of response speed and energy storage duration at the same time, and it is necessary to configure a certain scale of intraday and above energy storage forms. Hybrid energy storage can meet the application needs of scenarios such as smoothing the power fluctuations of new energy and promoting large-scale consumption of new energy by coupling energy storage with multiple different technical characteristics. Electrochemical energy storage has technical characteristics such as high energy density and fast response speed. The storage time is 2 to 4 hours, which can smooth the output of new energy and participate in the peak and frequency regulation of the system. It is currently the most widely used new energy storage. Molten salt has large heat storage capacity and low cost. It is mainly used in the field of heating and heat supply. The heat storage time is 6 to 15 hours. It can adjust the fluctuation of new energy for a long time, and complement electrochemical energy storage in terms of energy storage time. Molten salt heat storage coupled with coal-fired power unit transformation can realize peak shaving and valley filling of the power grid and improve the deep peak regulation capability of the unit. However, molten salt heat storage is currently only considered in the application scenario of solar thermal power generation, and there is little research on the application scenario of coupled thermal power units in the Shagohuang New Energy Base. Most of the existing technologies simulate and analyze the molten salt heat storage configuration scheme from a thermodynamic perspective. There are few studies on the participation of coal-fired power units in the power generation operation of the system after the heat storage transformation, and there is a lack of mathematical models suitable for analysis from the perspective of system operation. This means that after the molten salt heat storage is coupled with the thermal power unit transformation, there is a lack of system operation process analysis, and the electric and thermal hybrid energy storage capacity cannot be accurately configured, which is not conducive to the stable operation of the system. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the present application provides a hybrid energy storage optimization method and device considering molten salt heat storage coupled with thermal power units, which specifically adopts the following technical solutions:

[0004] A hybrid energy storage optimization method considering molten salt heat storage coupled with thermal power units is used to optimize the configuration of electrochemical energy storage and molten salt heat storage capacity in a hybrid energy storage system, which includes the following steps:

[0005] The basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit are analyzed, and the molten salt heat storage coupled thermal power unit transformation system is divided into boiler combustion device, high-pressure steam device, medium- and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device;

[0006] Based on the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, the energy flow of each device in the molten salt heat storage coupled thermal power unit transformation system is analyzed respectively, and the energy balance model of the corresponding device and the corresponding constraint conditions are constructed; wherein the energy balance model includes the energy balance model of the boiler combustion device, the energy balance model of the high-pressure steam device, the energy balance model of the medium and low-pressure steam device, the energy balance model of the superheating device, the energy balance model of the reheating device, the energy balance model of the generator device and the energy balance model of the molten salt heat storage device;

[0007] Based on the energy balance model of each device, a mathematical model of the corresponding molten salt heat storage coupled thermal power unit transformation system is constructed;

[0008] Analyze the impact of carbon emission trading on the optimal configuration of energy storage, and establish a double-layer optimal configuration model for the corresponding hybrid energy storage system; wherein the double-layer optimal configuration model includes an upper model and a lower model, the decision variables of the upper model are the rated power and rated capacity of the electrochemical energy storage and molten salt heat storage in the hybrid energy storage system, and the objective function is the total life cycle cost, including the hybrid energy storage investment cost and the system operation cost; the decision variables of the lower model are the power generation power of the thermal power unit and the charging and discharging power of the hybrid energy storage, and the objective function is the total operating cost;

[0009] The KKT method is used to solve the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system, and the optimal configuration strategy of the electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system is obtained.

[0010] Optionally, the steps of performing energy flow analysis on the boiler combustion device and constructing a corresponding energy balance model include:

[0011] Analyze the energy flow relationship of the boiler combustion device: the input energy of the boiler combustion device comes from the input power of the boiler combustion device, the output power of the superheating device and the output power of the reheating device; the output energy of the boiler combustion device enters the high-pressure steam device and the medium- and low-pressure steam devices respectively;

[0012] Based on the energy flow relationship of the boiler combustion device, the energy balance model of the boiler combustion device is: the sum of the input power of the boiler combustion device, the output power of the superheating device and the output power of the reheating device is equal to the sum of the input power of the high-pressure steam device and the medium- and low-pressure steam devices.

[0013] Optionally, the steps of performing energy flow analysis on the high-pressure steam device and constructing a corresponding energy balance model include:

[0014] Analyze the energy flow relationship of the high-pressure steam device: the input energy of the high-pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the high-pressure steam device is used to extract part of the steam to enter the input power of the superheating device, the exhaust heat power of the high-pressure steam device and the net heat energy of the high-pressure steam device;

[0015] Based on the energy flow relationship of the high-pressure steam device, the energy balance model of the high-pressure steam device is: the input power of the high-pressure steam device is equal to the sum of the input power of part of the steam extracted from the high-pressure steam device into the superheating device, the exhaust heat power of the high-pressure steam device and the net heat energy of the high-pressure steam device.

[0016] Optionally, the steps of performing energy flow analysis on the medium and low pressure steam device and constructing a corresponding energy balance model include:

[0017] Analyze the energy flow relationship of the medium and low pressure steam device: the input energy of the medium and low pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the medium and low pressure steam device is used to extract part of the steam to enter the input power of the reheating device, the exhaust heat power of the medium and low pressure steam device and the net heat energy of the medium and low pressure steam device;

[0018] Based on the energy flow relationship of the medium and low pressure steam devices, the energy balance model of the medium and low pressure steam devices is: the input power of the medium and low pressure steam devices is equal to the input power of part of the steam extracted from the medium and low pressure steam devices into the reheating device, the exhaust heat power of the medium and low pressure steam devices and the net heat energy of the medium and low pressure steam devices.

[0019] Optionally, the steps of performing energy flow analysis on the superheating device and constructing a corresponding energy balance model include:

[0020] Analyze the energy flow relationship of the superheater: the input energy of the superheater comes from the exhaust heat power of the medium and low pressure steam device and the heat release power of the molten salt heat storage device to the superheater; the output energy of the superheater flows to the input energy of the boiler combustion device;

[0021] Based on the energy flow relationship of the superheater, the energy balance model of the superheater is: the output power of the superheater is equal to the sum of the exhaust heat power of the medium and low pressure steam devices and the heat release power of the molten salt heat storage device to the superheater.

[0022] Optionally, the steps of performing energy flow analysis on the reheat device and constructing a corresponding energy balance model include:

[0023] Analyze the energy flow relationship of the reheat device: the input energy of the reheat device comes from the exhaust heat power of the high-pressure steam system; the output energy of the reheat device flows to the input energy of the boiler combustion device;

[0024] Based on the energy flow relationship of the reheat device, the energy balance model of the reheat device is: the output power of the reheat device is equal to the exhaust steam thermal power of the high-pressure steam device.

[0025] Optionally, the steps of performing energy flow analysis on the generator device and constructing a corresponding energy balance model include:

[0026] Analyze the energy flow relationship of the generator device: the output energy of the generator device comes from the thermoelectric conversion process of the net heat energy of the high-pressure steam device and the low-pressure steam device respectively;

[0027] Based on the energy flow relationship of the generator device, the energy balance model of the generator device is: the output power of the generator device is equal to the product of the thermoelectric conversion efficiency of the generator device and the sum of the net thermal energy of the high-pressure steam device and the low-pressure steam device.

[0028] Optionally: the steps of performing energy flow analysis on the molten salt heat storage device and constructing a corresponding energy balance model include:

[0029] Analyze the energy flow relationship of the molten salt heat storage device: the heat storage of the molten salt heat storage device comes from the heat storage of the previous period and the charging power of the superheating device and the reheating device; the heat storage of the molten salt heat storage device flows to the superheating device;

[0030] Based on the energy flow relationship of the molten salt heat storage device, the energy balance model of the molten salt heat storage device is: the heat storage amount between adjacent time periods of the molten salt heat storage device is equal to the sum of the difference between the heat charged and the heat released in the molten salt heat storage device and the heat not lost by the molten salt heat storage device.

[0031] Optional: The double-layer optimization configuration model of the hybrid energy storage system is:

[0032]

[0033] T cost (x, y) is the optimization objective function of the upper model; cost (x, y) is the optimization objective function of the lower model; x is the decision variable of the upper model; y is the decision variable of the lower model; f(x, y) is the constraint condition of the upper model; g(x, y) is the constraint condition of the lower model;

[0034] The data model of the upper model is:

[0035] T cost=I cost +O cost ;

[0036] Where T cost is the total life cycle cost; cost is the investment cost of the hybrid energy storage system; cost The operating costs of hybrid energy storage systems;

[0037] The average daily investment cost of the hybrid energy storage system is:

[0038]

[0039] Where C in is the average daily investment cost of the hybrid energy storage system; C bat is the average daily investment cost of electrochemical energy storage; C tes is the average daily investment cost of molten salt heat storage; γ is the discount rate; is the unit power cost of electrochemical energy storage; is the unit capacity cost of electrochemical energy storage; T bat is the useful life of electrochemical energy storage; is the rated power of electrochemical energy storage; is the rated capacity of electrochemical energy storage; The unit power cost of molten salt thermal storage; is the unit capacity cost of molten salt heat storage; T tes The service life of molten salt heat storage; is the rated power of molten salt thermal storage; is the rated capacity of molten salt heat storage;

[0040] The data model of the lower model is:

[0041] O cost =∑π r C op,r ;

[0042] Where O cost is the operating cost of the hybrid energy storage system; C op,r is the operating cost of the typical scenario r; π r is the probability of occurrence of typical scenario r;

[0043] The average daily operating cost for a typical scenario r is:

[0044] C op =C coal +C carbon +C penalty ;

[0045] Where C op is the average daily operating cost; C coalis the fuel cost consumed by thermal power units; C carbon is the carbon emission cost of thermal power units; C penalty Penalty costs for curtailing wind and solar power in hybrid energy storage systems;

[0046] The constraints of the upper model in the two-layer optimization configuration model of the hybrid energy storage system include the rated power and capacity installation restrictions of the hybrid energy storage; the constraints of the lower model include power balance constraints, thermal power unit restriction processing constraints, wind power and photovoltaic power constraints, electrochemical energy storage operation constraints, molten salt heat storage operation constraints and external transmission channel constraints.

[0047] Furthermore, the present application also discloses a hybrid energy storage optimization device considering molten salt heat storage coupled with a thermal power unit, which is used to optimize the configuration of electrochemical energy storage and molten salt heat storage capacity in a hybrid energy storage system, and the device comprises:

[0048] The structural division module is used to analyze the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and divide the molten salt heat storage coupled thermal power unit transformation system into boiler combustion device, high-pressure steam device, medium and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device;

[0049] An energy flow analysis module is used to analyze the energy flow of each device in the molten salt heat storage coupled thermal power unit transformation system based on the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and to construct an energy balance model of the corresponding device and corresponding constraints; wherein the energy balance model includes an energy balance model of a boiler combustion device, an energy balance model of a high-pressure steam device, an energy balance model of a medium- and low-pressure steam device, an energy balance model of a superheating device, an energy balance model of a reheating device, an energy balance model of a generator device, and an energy balance model of a molten salt heat storage device;

[0050] A mathematical model building module is used to build a mathematical model of the corresponding molten salt heat storage coupled thermal power unit transformation system based on the energy balance model of each device;

[0051] A two-layer optimization model building module is used to analyze the impact of carbon emission trading on the optimal configuration of energy storage, and establish a two-layer optimization configuration model for the corresponding hybrid energy storage system; wherein the two-layer optimization configuration model includes an upper model and a lower model, wherein the decision variables of the upper model are the rated power and rated capacity of the electrochemical energy storage and molten salt heat storage in the hybrid energy storage system, and the objective function is the total life cycle cost, including the hybrid energy storage investment cost and the system operation cost; wherein the decision variables of the lower model are the power generation power of the thermal power unit and the charging and discharging power of the hybrid energy storage, and the objective function is the total operating cost;

[0052] The solution result output module is used to solve the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system using the KKT method, and obtain the optimal configuration strategy of the electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system.

[0053] Beneficial Effects

[0054] The technical solution of this application has the following beneficial effects:

[0055] (1) The hybrid energy storage optimization method of this application is based on the internal energy flow relationship of the deep coupling of molten salt heat storage and thermal power units, and establishes a mathematical model for the operation analysis of the corresponding molten salt heat storage coupled thermal power unit transformation system. The deep coupling model has higher accuracy and the relevant calculation results are more in line with the actual situation. Through the model calculation results, the electrochemical energy storage and molten salt heat storage capacity can be reasonably optimized to achieve multi-energy complementarity of different types of energy, improve the system's flexible adjustment capabilities, increase the utilization rate of new energy and the proportion of renewable energy in the transmission channel, and reduce the system's operating costs.

[0056] (2) The hybrid energy storage optimization method of this application introduces the carbon emission rights trading mechanism into the energy storage optimization configuration problem. Taking into account the carbon emission trading of thermal power units, it can effectively control the carbon emissions of the units in the actual operation of the hybrid energy storage system and promote the investment and construction entities to improve their carbon asset management capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Flow chart of the hybrid energy storage optimization method in an embodiment of the present application.

[0058] Figure 2 This is a schematic diagram of the structure of the Shagohuang new energy base system in the embodiment of the present application.

[0059] Figure 3 It is a schematic diagram of the internal energy flow relationship of the molten salt heat storage coupled thermal power unit transformation system in the embodiment of the present application.

[0060] Figure 4 This is a typical wind power output curve diagram for spring, summer, autumn and winter scenarios after normalization in the embodiment of the present application.

[0061] Figure 5 This is a graph showing the typical photovoltaic output curve in spring, summer, autumn and winter scenarios after normalization in the embodiment of the present application.

[0062] Figure 6 Schematic diagram of the structure of the hybrid energy storage optimization device in the embodiment of the present application.

[0063] Figure 7 This is a structural diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0064] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and cannot be used to limit the scope of protection of the present application. It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present application.

[0065] Combination Figure 1 As shown, the embodiment of the present application specifically discloses a hybrid energy storage optimization method considering molten salt heat storage coupled with thermal power units, which is used to optimize the configuration of electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system. This embodiment is described in detail with the system structure of the Shagohuang New Energy Base containing hybrid energy storage, in which the hybrid energy storage mainly consists of two forms of energy storage: electrochemical energy storage and molten salt heat storage, in which the molten salt heat storage is configured in the form of coupled thermal power unit transformation. Figure 2 As shown in the figure, the Shagohuang New Energy Base system is mainly composed of wind power generation, photovoltaic power generation, thermal power generation, electrochemical energy storage, molten salt heat storage and external power transmission channels. The base contains two energy flow processes, electricity and heat. The power transmission demand is mainly met by wind power generation, photovoltaic power generation, thermal power generation and electrochemical energy storage through the ultra-high voltage power transmission channel, while the thermal energy part is limited to the internal circulation of the molten salt heat storage system and the thermal power unit, and does not consider the supply of heat and steam to the external system. When the output of new energy is greater than the demand for power transmission, on the one hand, the Shagohuang New Energy Base can absorb the surplus power of new energy through electrochemical energy storage, and on the other hand, the Shagohuang New Energy Base reduces the output of the thermal power units through the coupling molten salt heat storage transformation to deeply adjust the peak and promote the consumption of new energy. When the output of new energy is less than the demand for power transmission, the electrochemical energy storage releases the stored electricity, and at the same time, the molten salt heat storage releases the stored heat to work through the boiler and steam turbine, quickly increasing the output of the thermal power unit and giving full play to the peak effect, especially during the peak summer and peak winter.

[0066] In detail, the hybrid energy storage optimization method in this embodiment includes the following steps:

[0067] Step 1: Analyze the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and divide the molten salt heat storage coupled thermal power unit transformation system into boiler combustion device, high-pressure steam device, medium and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device.

[0068] The basic structure of the molten salt heat storage coupled thermal power unit transformation system in this embodiment includes four parts: a host module, a heat charging module, a heat release module and a molten salt heat storage system module. The host module includes equipment such as a boiler, a steam turbine, and a condenser; the heat charging module includes a reheat heater, a superheat heater, a phase change heater, and a preheat heater; the heat release module includes a superheater, an evaporator, and a preheater; the molten salt heat storage system adopts a double-tank molten salt system, which is composed of a high-temperature molten salt storage tank and a low-temperature molten salt storage tank.

[0069] Based on the principle analysis of the basic structure of the hybrid energy storage system, three assumptions are proposed: 1) Ignore the heat loss of the heat transfer pipeline; 2) Ignore the molten salt working fluid circulation loss; 3) Ignore the heat exchange loss of water vapor and molten salt. In order to facilitate the description of the internal energy flow relationship of the system after the molten salt heat storage coupled thermal power unit is transformed, this embodiment further divides the molten salt heat storage coupled thermal power unit transformation system into seven parts: boiler combustion device, high-pressure steam device, medium and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device. The internal energy flow relationship of the molten salt heat storage coupled thermal power unit transformation system is as follows: Figure 3 shown.

[0070] Step 2: Based on the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, the energy flow of each device in the molten salt heat storage coupled thermal power unit transformation system is analyzed respectively, and the energy balance model of the corresponding device and the corresponding constraints are constructed; wherein the energy balance model includes the energy balance model of the boiler combustion device, the energy balance model of the high-pressure steam device, the energy balance model of the medium and low-pressure steam device, the energy balance model of the superheating device, the energy balance model of the reheating device, the energy balance model of the generator device and the energy balance model of the molten salt heat storage device.

[0071] (1) The step of performing energy flow analysis on the boiler combustion device and constructing a corresponding energy balance model in step 2 of this embodiment includes:

[0072] Analyze the energy flow relationship of the boiler combustion device: the input energy of the boiler combustion device comes from the input power of the boiler combustion device, the output power of the superheating device and the output power of the reheating device; the output energy of the boiler combustion device enters the high-pressure steam device and the medium and low-pressure steam devices respectively.

[0073] Based on the energy flow relationship of the boiler combustion device, the energy balance model of the boiler combustion device is: the sum of the input power of the boiler combustion device, the output power of the superheating device and the output power of the reheating device is equal to the sum of the input power of the high-pressure steam device and the medium- and low-pressure steam devices, that is:

[0074]

[0075] Where P coal,t It represents the input power of the boiler combustion device during the period t; represents the output power of the overheating device during period t; represents the output power of the reheat device during period t; represents the input power of the high-pressure steam device during period t; Represents the input power of the low-pressure steam device during period t.

[0076] In addition, the water vapor from the boiler combustion device must satisfy the mass balance:

[0077]

[0078] Where: Indicates the quality of steam output by the superheater during period t; It represents the quality of steam output from the reheat system during period t; It represents the quality of steam input into the high pressure steam system during period t; Indicates the quality of steam input into the medium and low pressure steam system during period t.

[0079] It should be noted that the input power of the boiler combustion device comes from the energy generated by the combustion of pulverized coal:

[0080] P coal,t =η coal Q coal M t / Δt;

[0081] where η coal is the combustion efficiency of pulverized coal in the boiler; Q coal Indicates the calorific value of coal powder combustion; M t It indicates the combustion quality of pulverized coal in the boiler during a period of time; Δt indicates the time interval.

[0082] Furthermore, the mass of coal consumed by the boiler in the boiler combustion device per unit time must satisfy the following formula:

[0083] M min ≤M t ≤M max ;

[0084] Where M min is the minimum mass of pulverized coal combustion; M max It is the maximum mass of coal powder combustion.

[0085] (2) The step of performing energy flow analysis on the high-pressure steam device and constructing a corresponding energy balance model in step 2 of this embodiment includes:

[0086] Analyze the energy flow relationship of the high-pressure steam device: the input energy of the high-pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the high-pressure steam device is used to extract part of the steam to enter the input power of the superheating device, the exhaust heat power of the high-pressure steam device and the net heat energy of the high-pressure steam device;

[0087] Based on the energy flow relationship of the high-pressure steam device, the energy balance model of the high-pressure steam device is: the input power of the high-pressure steam device is equal to the sum of the input power of the part of steam extracted from the high-pressure steam device into the superheating device, the exhaust heat power of the high-pressure steam device and the net heat energy of the high-pressure steam device, that is:

[0088]

[0089] In the formula represents the input power of steam extracted from the high-pressure steam device into the superheater during period t;

[0090] It represents the exhaust power of the high-pressure steam device during the period t; Represents the net heat energy used by the high-pressure steam unit during period t.

[0091] It should be noted that the water vapor of the high-pressure steam device must satisfy the mass balance:

[0092]

[0093] In the formula represents the mass of steam extracted from the high-pressure steam device during period t; Indicates the exhaust quality of the high-pressure steam device during period t.

[0094] In addition, in order to ensure the safety and reliability of the output power, the power of steam extracted from the high-pressure steam device and the net heat energy used by the high-pressure steam device should be limited:

[0095]

[0096] Where α hpc The coefficient that limits the extraction thermal power of the high-pressure steam unit; Indicates the lower limit of net heat energy used by high pressure steam plant; Represents the upper limit of the net thermal energy used by a high pressure steam plant.

[0097] (3) The steps of performing energy flow analysis on the medium and low pressure steam device and constructing a corresponding energy balance model in step 2 of this embodiment include:

[0098] Analyze the energy flow relationship of the medium and low pressure steam device: the input energy of the medium and low pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the medium and low pressure steam device is used to extract part of the steam to enter the input power of the reheating device, the exhaust heat power of the medium and low pressure steam device and the net heat energy of the medium and low pressure steam device;

[0099] Based on the energy flow relationship of the medium and low pressure steam device, the energy balance model of the medium and low pressure steam device is: the input power of the medium and low pressure steam device is equal to the sum of the input power of the medium and low pressure steam device extracting part of the steam into the reheating device, the exhaust heat power of the medium and low pressure steam device and the net heat energy of the medium and low pressure steam device: that is:

[0100]

[0101] In the formula It represents the input power of steam extracted from the medium and low pressure steam devices into the reheat device during period t; It represents the exhaust power of medium and low pressure steam devices in period t; Represents the net heat energy used by the low-pressure steam unit during period t.

[0102] It should be noted that the water vapor of the medium and low pressure steam device described in this embodiment should satisfy the mass balance:

[0103]

[0104] In the formula It represents the quality of steam extracted from the medium and low pressure steam devices during the period t; Indicates the exhaust quality of low-pressure steam devices during period t.

[0105] Furthermore, in order to ensure the safe and reliable output of electric energy, the power of steam extracted from the medium and low pressure steam devices and the net heat energy used by the medium and low pressure steam devices should be limited:

[0106]

[0107] Where α mlpc The coefficient that limits the extraction thermal power of medium and low pressure steam units; It indicates the lower limit of the net heat energy used by medium and low pressure steam plants; Represents the upper limit of the net heat energy used by medium and low pressure steam plants.

[0108] (4) The step of performing energy flow analysis on the superheating device and constructing a corresponding energy balance model in step 2 of this embodiment includes:

[0109] The energy flow relationship of the superheater is analyzed: the input energy of the superheater comes from the exhaust heat power of the medium and low pressure steam devices and the heat release power of the molten salt heat storage device to the superheater; the output energy of the superheater flows to the input energy of the boiler combustion device; the steam is extracted from the high pressure steam device and passes through the superheater to form condensed water which returns to the boiler combustion device, which can improve the system efficiency of the molten salt heat storage coupled thermal power unit.

[0110] Based on the energy flow relationship of the superheater, the energy balance model of the superheater is: the output power of the superheater is equal to the sum of the exhaust heat power of the medium and low pressure steam device and the heat release power of the molten salt heat storage device to the superheater, that is:

[0111]

[0112] In the formula It represents the heat release power of the molten salt heat storage device to the superheater during the period t.

[0113] It should be noted that the water vapor in the superheater described in this embodiment should satisfy the mass balance:

[0114]

[0115] In addition, the output power of the superheater and the exhaust heat power of the medium and low pressure steam devices should be limited:

[0116]

[0117] Where β su Indicates the limiting factor of the output power of the overheating device; Indicates the minimum thermal power coefficient of exhaust steam from medium and low pressure steam devices; Indicates the maximum thermal power coefficient of exhaust steam from medium and low pressure steam systems.

[0118] (5) The step of performing energy flow analysis on the reheat device and constructing a corresponding energy balance model in step 2 of this embodiment includes:

[0119] Analyze the energy flow relationship of the reheat device: the input energy of the reheat device comes from the exhaust heat power of the high-pressure steam system; the output energy of the reheat device flows to the input energy of the boiler combustion device;

[0120] Based on the energy flow relationship of the reheat device, the energy balance model of the reheat device is: the output power of the reheat device is equal to the exhaust heat power of the high-pressure steam device, that is:

[0121]

[0122] Furthermore, the reheat device needs to satisfy the mass balance:

[0123]

[0124] In addition, it is also necessary to limit the output power of the reheat device and the exhaust heat power of the high-pressure steam device:

[0125]

[0126] Where βre Indicates the limiting factor of the reheat unit output power; Indicates the minimum thermal power coefficient of the exhaust steam of the high-pressure steam device; Indicates the maximum thermal power coefficient of exhaust steam from a high-pressure steam system.

[0127] (6) The step of performing energy flow analysis on the generator device and constructing a corresponding energy balance model in step 2 of this embodiment includes:

[0128] Analyze the energy flow relationship of the generator device: the output energy of the generator device comes from the thermoelectric conversion process of the net heat energy of the high-pressure steam device and the low-pressure steam device respectively;

[0129] Based on the energy flow relationship of the generator device, the energy balance model of the generator device is: the output power of the generator device is equal to the product of the thermoelectric conversion efficiency of the generator device and the sum of the net heat energy of the high-pressure steam device and the low-pressure steam device, that is:

[0130]

[0131] Where P g,t represents the generator output power in period t; η g Represents the thermoelectric conversion efficiency.

[0132] (7) The step of performing energy flow analysis on the molten salt heat storage device and constructing a corresponding energy balance model in step 2 of this embodiment includes:

[0133] Analyze the energy flow relationship of the molten salt heat storage device: The heat storage capacity of the molten salt heat storage is not only related to the charging and discharging power, but also to the heat storage capacity and heat dissipation loss in the previous period. The heat storage capacity of the molten salt heat storage device comes from the heat storage capacity of the previous period and the charging power of the superheater and reheater; the heat storage capacity of the molten salt heat storage device flows to the superheater;

[0134] Based on the energy flow relationship of the molten salt heat storage device, the energy balance model of the molten salt heat storage device is: the heat storage amount between adjacent time periods of the molten salt heat storage device is equal to the sum of the difference between the heat charged and the heat released in the molten salt heat storage device and the heat not lost by the molten salt heat storage device, that is:

[0135]

[0136] Where E tes,t and E tes,t-1 They represent the heat storage capacity of the molten salt heat storage device in period t and period t-1 respectively; represents the heat loss rate of the molten salt heat storage device; It represents the charging power of the molten salt heat storage device from the superheating device and the reheating device during the period t; and They represent the charging and releasing efficiencies of the molten salt heat storage device respectively.

[0137] The heat release power of molten salt heat storage is:

[0138]

[0139] The charging power of the molten salt heat storage is shown as follows:

[0140]

[0141] Furthermore, in order to ensure the stable and reliable operation of molten salt heat storage, the energy and charging and discharging power of molten salt heat storage need to be limited:

[0142]

[0143] in represents the minimum thermal energy of molten salt heat storage; Indicates the rated capacity of molten salt thermal storage; Indicates the rated power of molten salt thermal storage; Indicates the heat release state of molten salt heat storage in period t, which is a 0-1 variable; Indicates the charging state of the molten salt heat storage in period t, which is a 0-1 variable.

[0144] Step three: Construct a mathematical model of the corresponding molten salt heat storage coupled thermal power unit transformation system based on the energy balance model of each device; in this step three, by combining the energy balance model of the boiler combustion device, the energy balance model of the high-pressure steam device, the energy balance model of the medium and low-pressure steam device, the energy balance model of the superheating device, the energy balance model of the reheating device, the energy balance model of the generator device and the energy balance model of the molten salt heat storage device and the corresponding constraints, the mathematical model of the molten salt heat storage coupled thermal power unit transformation system can be obtained.

[0145] Step 4: Analyze the impact of carbon emission trading on the optimal configuration of energy storage, and establish a two-layer optimal configuration model for the corresponding hybrid energy storage system; wherein the two-layer optimal configuration model includes an upper model and a lower model, the decision variables of the upper model are the rated power and rated capacity of the electrochemical energy storage and molten salt heat storage in the hybrid energy storage system, and the objective function is the total life cycle cost, including the hybrid energy storage investment cost and the system operating cost; the decision variables of the lower model are the power generation power of the thermal power unit and the charging and discharging power of the hybrid energy storage, and the objective function is the total operating cost.

[0146] Specifically, the double-layer optimization configuration model of the hybrid energy storage system is:

[0147]

[0148] T cost (x, y) is the optimization objective function of the upper model; cost (x,y) is the optimization objective function of the lower model; x is the decision variable of the upper model; y is the decision variable of the lower model; f(x,y) is the constraint of the upper model; g(x,y) is the constraint of the lower model. The above two-level optimization configuration model includes two levels of optimization tasks. The lower-level operation optimization is nested in the upper-level configuration optimization, and the upper-level configuration results provide boundary conditions for the lower-level operation optimization.

[0149] The data model of the upper model is:

[0150] T cost =I cost +O cost ;

[0151] Where T cost is the total life cycle cost; cost is the investment cost of the hybrid energy storage system; cost The operating costs of hybrid energy storage systems;

[0152] The average daily investment cost of the hybrid energy storage system is:

[0153]

[0154] Where C in is the average daily investment cost of the hybrid energy storage system; C bat is the average daily investment cost of electrochemical energy storage; C tes is the average daily investment cost of molten salt heat storage; γ is the discount rate; is the unit power cost of electrochemical energy storage; is the unit capacity cost of electrochemical energy storage; T bat is the useful life of electrochemical energy storage; is the rated power of electrochemical energy storage; is the rated capacity of electrochemical energy storage; The unit power cost of molten salt thermal storage; is the unit capacity cost of molten salt heat storage; T tes The service life of molten salt heat storage; is the rated power of molten salt thermal storage; is the rated capacity of molten salt heat storage.

[0155] The data model of the lower model is:

[0156] O cost =Σπ r C op,r ;

[0157] Where Ocost is the operating cost of the hybrid energy storage system; C op,r is the operating cost of a typical scenario r; π r is the probability of occurrence of typical scenario r;

[0158] The average daily operating cost for a typical scenario r is:

[0159] C op =C coal +C carbon +C penalty ;

[0160] Where C op is the average daily operating cost; C coal is the fuel cost consumed by thermal power units; C carbon is the carbon emission cost of thermal power units; C penalty Penalty costs for curtailing wind and solar power in hybrid energy storage systems.

[0161] The fuel cost consumed by the thermal power unit and the penalty cost of wind and solar power abandonment of the hybrid energy storage system are calculated by the following formula:

[0162]

[0163] Where λ coal Indicates the unit standard coal price; M t,i represents the mass of pulverized coal consumed by thermal power unit i in period t; T represents the number of periods in the operation cycle; N represents the number of thermal power units; λ wp represents the unit wind curtailment cost; pv Indicates the unit abandoned light cost; Indicates the wind power abandoned during period t; Indicates the abandoned solar power output during period t.

[0164] The carbon emission trading cost of thermal power units can be calculated by the following formula:

[0165] C carbon,t =λ carbon (D carbon,t -D ini,t );

[0166] Where C carbon,t is the carbon emission rights trading cost of thermal power units in period t; carbon is the carbon emission rights trading price coefficient; D carbon,t is the actual carbon emissions of the thermal power unit in period t; D ini,t is the carbon emission quota of the thermal power unit in period t.

[0167] The constraints of the upper model in the two-layer optimization configuration model of the hybrid energy storage system include the rated power and capacity installation restrictions of the hybrid energy storage; the constraints of the lower model include power balance constraints, thermal power unit restriction processing constraints, wind power and photovoltaic power constraints, electrochemical energy storage operation constraints, molten salt heat storage operation constraints and external transmission channel constraints.

[0168] The hybrid energy storage rated power constraints include:

[0169]

[0170] In the formula They represent the minimum and maximum rated powers of electrochemical energy storage and molten salt thermal storage, respectively; Represent the minimum and maximum values ​​of the rated capacity of electrochemical energy storage and molten salt thermal storage, respectively.

[0171] Furthermore, the power balance constraint includes:

[0172] P wp,t +P pv,t +P g,t +P bat,t =P dc,t ;

[0173] Where P wp,t represents the actual output of wind power generation in period t; P pv,t represents the actual output of photovoltaic power generation in period t; P bat,t represents the charge and discharge power of electrochemical energy storage in time period t; P dc,t It represents the DC transmission power in time period t.

[0174] The output limit constraints of the thermal power generation units include:

[0175] Output boundary conditions of thermal power units:

[0176] Thermal power unit ramp rate limit:

[0177] In the formula Indicates the rated power of thermal power unit; Indicates the load reduction rate of thermal power units; Indicates the output ramp rate of thermal power units.

[0178] The wind power and photovoltaic power constraints include:

[0179] (1) The power generation capacity constraint range is:

[0180]

[0181] Where δ wp,t and δpv,t They represent the theoretical normalized output of wind power generation and photovoltaic power generation in period t respectively;

[0182] and They represent wind power installed capacity and photovoltaic installed capacity respectively.

[0183] (2) The new energy utilization rate constraint is:

[0184]

[0185] Where ε is the utilization rate of wind power and photovoltaic power.

[0186] (3) Wind and solar curtailment constraints include:

[0187]

[0188] The electrochemical energy storage operation constraints include:

[0189] The charge and discharge power constraints are:

[0190]

[0191] In the formula represents the discharge power of electrochemical energy storage in period t; represents the charging power of electrochemical energy storage in period t; Indicates the discharge state of the energy storage in period t, which is a 0-1 variable; Indicates the charging state of the energy storage at time period t, which is a 0-1 variable.

[0192] The charge and discharge state constraints are:

[0193] The state of charge constraints are:

[0194] Where E bat,t It represents the storage capacity of electrochemical energy storage in time period t; E bat,t-1 It represents the storage capacity of electrochemical energy storage in the period t-1; Indicates the self-discharge rate of electrochemical energy storage; Indicates the energy storage charging efficiency; Indicates the energy storage power generation efficiency.

[0195] The capacity constraint is:

[0196] In the formula Indicates the minimum storage capacity of electrochemical energy storage; Indicates the maximum storage capacity of electrochemical energy storage.

[0197] The storage capacity constraints of the initial and final states of electrochemical energy storage are:

[0198] In the formula Indicates the amount of stored electricity in the initial state; Indicates the stored power at the end state.

[0199] The molten salt thermal storage operation constraints include:

[0200] Charge and discharge thermal power constraints:

[0201] Where P tes,t It represents the charging and releasing power of molten salt heat storage in time period t.

[0202] The heat storage capacity constraints of the initial and final states of molten salt heat storage are:

[0203] In the formula represents the heat storage capacity at the initial state; Indicates the thermal storage capacity at the end state.

[0204] The outbound channel constraints include:

[0205] The power boundary condition of the transmission channel is:

[0206] In the formula and They are respectively the lower and upper limits of the system's external transmission channel power.

[0207] The power consumption constraint of the transmission channel is:

[0208] Where ζ represents the proportion of renewable energy electricity in the transmission channel.

[0209] Step 5: Use the KKT method to solve the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system to obtain the optimal configuration strategy for electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system. In this application, the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system together constitute the hybrid energy storage optimization configuration model of the Shagohuang New Energy Base in this embodiment. Analysis of the established double-layer optimization model shows that the lower-level optimization problem is a continuous differentiable convex function, and the KKT method can be used to convert the double-layer optimization problem into a single-layer optimization problem for solution. The converted single-layer model belongs to a mixed integer linear programming problem. This embodiment is based on MATLAB-2024a platform programming and uses the YALMIP toolkit to call the CPLEX mathematical optimization solver for solution.

[0210] Furthermore, this embodiment takes a large-scale new energy base in Ordos, Kubuqi Desert, Inner Mongolia Autonomous Region as an example, and uses the above-mentioned method to optimize the configuration of energy storage power and capacity in the system for verification. The system includes 8000MW of photovoltaic power generation, 4000MW of wind power generation, 4 thermal power units with a single capacity of 1000MW, and a certain proportion of supporting energy storage projects. A new ±800kV ultra-high voltage direct current transmission project from Ordos to the central and eastern regions is built, with a maximum power transmission capacity of 8000MW to meet the green and low-carbon energy consumption needs of the receiving areas. This embodiment uses the historical data of wind and solar stations in the Kubuqi Desert area of ​​Inner Mongolia Autonomous Region, selects wind power generation and photovoltaic power generation data on four typical days in spring, summer, autumn and winter, and reconstructs a 96-hour output curve for simulation analysis, and obtains the annual investment and operation of energy storage and base operation costs according to the probability weighting of the scenarios. Figure 4 and 5 As shown, it is a normalized typical day wind and solar output curve in spring, summer, autumn and winter.

[0211] This embodiment is based on a comparative analysis of three scenarios: Scenario 1 (basic scenario) Shagohuang New Energy Base is only equipped with a single electrochemical energy storage; Scenario 2 (ideal scenario) Shagohuang New Energy Base is equipped with two types of energy storage, electrochemical energy storage and molten salt heat storage. Molten salt heat storage and thermal power units are simple combinations under ideal conditions, ignoring the idealized model of the coupling relationship between thermal power units; Scenario 3 (coupling scenario) Shagohuang New Energy Base is equipped with two types of energy storage, electrochemical energy storage and molten salt heat storage, and considers the deep coupling of the molten salt heat storage transformation of the thermal power unit, that is, the method proposed in this application. The results of the hybrid energy storage optimization configuration of Shagohuang New Energy Base in each scenario are shown in Table 1:

[0212] Table 1

[0213]

[0214] From the above energy storage optimization configuration results, it can be seen that the rated power of electrochemical energy storage in the basic scenario, ideal scenario and coupling scenario is similar, and the supporting energy storage scale accounts for 19.7%, 19.0% and 20% of the installed capacity of new energy, respectively. In addition, the charging and discharging time of electrochemical energy storage in the basic scenario, ideal scenario and coupling scenario are 3.05h, 3.06h and 3.20h, respectively. On the other hand, compared with the ideal scenario, the rated power and rated capacity of molten salt thermal storage in the coupling scenario are slightly increased.

[0215] In terms of economic costs, the basic scenario has the highest total annual cost, which is 157 million yuan and 89 million yuan more than the ideal scenario and the coupled scenario, respectively, an increase of 2.3% and 1.3%, respectively. The annual fuel cost and annual carbon emission cost of thermal power units in the basic scenario are the highest, and the cost of wind and solar abandonment is also the highest. After the base has been transformed through the molten salt heat storage coupled thermal power unit, the peak load potential of the thermal power unit has been fully tapped, the flexibility of the thermal power unit has been improved, and its minimum output has been further reduced. At the same time, during the peak period of electricity consumption at the receiving end, the thermal power unit can rely on the energy released by molten salt heat storage and boiler combustion to jointly meet the load demand, reducing coal combustion and carbon emissions. After the base was equipped with electrochemical energy storage and molten salt heat storage, although the investment cost increased, the operating cost dropped significantly. Compared with the basic scenario, the energy storage investment costs of the ideal scenario and the coupled scenario increased by 79 million and 234 million yuan, respectively, an increase of 4.2% and 12.6%, respectively. The operating costs of the ideal scenario and the coupled scenario decreased by 236 million and 324 million yuan, respectively, a decrease of 4.8% and 6.6%, respectively. In addition, the coupled scenario can make full use of wind and solar resources and reduce the cost of wind and solar abandonment. Its new energy utilization rate and renewable energy share can be increased by at least 1 percentage point compared with the basic scenario. In summary, the mathematical modeling of the transformation of molten salt heat storage coupled thermal power units can improve the accuracy of the model to a certain extent, which can not only realize the complementary advantages of multiple types of energy storage, but also effectively improve the economy of the base.

[0216] At the same time, the thermal power units coupled with molten salt heat storage transformation can flexibly participate in the system peak regulation and absorb new energy, reducing the cost of wind and solar power abandonment in the base. The connected new energy will replace the thermal power start-up capacity, further reducing the fuel cost required for boiler combustion. Overall, the increase in the annual carbon emission cost of the base is smaller than the decrease in the cost of wind and solar power abandonment and the annual fuel cost, so the total operating cost of the base shows a downward trend.

[0217] In addition, Figure 6 As shown, the present application also discloses a hybrid energy storage optimization device considering molten salt heat storage coupled with a thermal power unit, which is used for optimizing the configuration of electrochemical energy storage and molten salt heat storage capacity in a hybrid energy system, and the device comprises:

[0218] The structural division module is used to analyze the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and divide the molten salt heat storage coupled thermal power unit transformation system into boiler combustion device, high-pressure steam device, medium and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device;

[0219] An energy flow analysis module is used to analyze the energy flow of each device in the molten salt heat storage coupled thermal power unit transformation system based on the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and to construct an energy balance model of the corresponding device and corresponding constraints; wherein the energy balance model includes an energy balance model of a boiler combustion device, an energy balance model of a high-pressure steam device, an energy balance model of a medium- and low-pressure steam device, an energy balance model of a superheating device, an energy balance model of a reheating device, an energy balance model of a generator device, and an energy balance model of a molten salt heat storage device;

[0220] A mathematical model building module is used to build a mathematical model of the corresponding molten salt heat storage coupled thermal power unit transformation system based on the energy balance model of each device;

[0221] A two-layer optimization model building module is used to analyze the impact of carbon emission trading on the optimal configuration of energy storage, and establish a two-layer optimization configuration model for the corresponding hybrid energy storage system; wherein the two-layer optimization configuration model includes an upper model and a lower model, wherein the decision variables of the upper model are the rated power and rated capacity of the electrochemical energy storage and molten salt heat storage in the hybrid energy storage system, and the objective function is the total life cycle cost, including the hybrid energy storage investment cost and the system operation cost; wherein the decision variables of the lower model are the power generation power of the thermal power unit and the charging and discharging power of the hybrid energy storage, and the objective function is the total operating cost;

[0222] The solution result output module is used to solve the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system using the KKT method, and obtain the optimal configuration strategy of the electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system.

[0223] The device provided in the embodiment of the present application can achieve Figure 1 To avoid repetition, the various processes implemented by the method embodiment will not be described again here.

[0224] like Figure 7 As shown, the embodiment of the present application also provides an electronic device, including a processor and a memory, a program or instruction stored in the memory and executable on the processor, and when the program or instruction is executed by the processor, the following is achieved: Figure 1 The various processes of the method embodiment shown in the figure can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0225] The embodiment of the present application also provides a readable storage medium on which a program or instruction is stored. When the program or instruction is executed by a processor, the above Figure 1 The various processes of the method embodiments described above can achieve the same technical effect, and will not be described again here to avoid repetition.

[0226] The present application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the above Figure 1 The various processes of the method embodiments described above can achieve the same technical effect, and will not be described again here to avoid repetition.

[0227] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0228] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0229] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another device, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0230] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0231] In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0232] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, etc., various media that can store program codes.

[0233] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a device (which can be a terminal or a platform, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0234] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A hybrid energy storage optimization method considering molten salt heat storage coupled with thermal power units, which is used to optimize the configuration of electrochemical energy storage and molten salt heat storage capacity in a hybrid energy storage system, characterized in that: The steps include: The basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit are analyzed, and the molten salt heat storage coupled thermal power unit transformation system is divided into boiler combustion device, high-pressure steam device, medium- and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device; Based on the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, the energy flow of each device in the molten salt heat storage coupled thermal power unit transformation system is analyzed respectively, and the energy balance model of the corresponding device and the corresponding constraint conditions are constructed; wherein the energy balance model includes the energy balance model of the boiler combustion device, the energy balance model of the high-pressure steam device, the energy balance model of the medium and low-pressure steam device, the energy balance model of the superheating device, the energy balance model of the reheating device, the energy balance model of the generator device and the energy balance model of the molten salt heat storage device; Based on the energy balance model of each device, a mathematical model of the corresponding molten salt heat storage coupled thermal power unit transformation system is constructed; Analyze the impact of carbon emission trading on the optimal configuration of energy storage, and establish a double-layer optimal configuration model for the corresponding hybrid energy storage system; wherein the double-layer optimal configuration model includes an upper model and a lower model, the decision variables of the upper model are the rated power and rated capacity of the electrochemical energy storage and molten salt heat storage in the hybrid energy storage system, and the objective function is the total life cycle cost, including the hybrid energy storage investment cost and the system operation cost; the decision variables of the lower model are the power generation power of the thermal power unit and the charging and discharging power of the hybrid energy storage, and the objective function is the total operating cost; The KKT method is used to solve the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system, and the optimal configuration strategy of the electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system is obtained.

2. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the boiler combustion device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the boiler combustion device: the input energy of the boiler combustion device comes from the input power of the boiler combustion device, the output power of the superheating device and the output power of the reheating device; the output energy of the boiler combustion device enters the high-pressure steam device and the medium- and low-pressure steam devices respectively; Based on the energy flow relationship of the boiler combustion device, the energy balance model of the boiler combustion device is: the sum of the input power of the boiler combustion device, the output power of the superheating device and the output power of the reheating device is equal to the sum of the input power of the high-pressure steam device and the medium- and low-pressure steam devices.

3. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the high pressure steam device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the high-pressure steam device: the input energy of the high-pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the high-pressure steam device is used to extract part of the steam to enter the input power of the superheating device, the exhaust heat power of the high-pressure steam device and the net heat energy of the high-pressure steam device; Based on the energy flow relationship of the high-pressure steam device, the energy balance model of the high-pressure steam device is: the input power of the high-pressure steam device is equal to the sum of the input power of part of the steam extracted from the high-pressure steam device into the superheating device, the exhaust heat power of the high-pressure steam device and the net heat energy of the high-pressure steam device.

4. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the medium and low pressure steam device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the medium and low pressure steam device: the input energy of the medium and low pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the medium and low pressure steam device is used to extract part of the steam to enter the input power of the reheating device, the exhaust heat power of the medium and low pressure steam device and the net heat energy of the medium and low pressure steam device; Based on the energy flow relationship of the medium and low pressure steam devices, the energy balance model of the medium and low pressure steam devices is: the input power of the medium and low pressure steam devices is equal to the input power of part of the steam extracted from the medium and low pressure steam devices into the reheating device, the exhaust heat power of the medium and low pressure steam devices and the net heat energy of the medium and low pressure steam devices.

5. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the superheating device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the superheater: the input energy of the superheater comes from the exhaust heat power of the medium and low pressure steam device and the heat release power of the molten salt heat storage device to the superheater; the output energy of the superheater flows to the input energy of the boiler combustion device; Based on the energy flow relationship of the superheater, the energy balance model of the superheater is: the output power of the superheater is equal to the sum of the exhaust heat power of the medium and low pressure steam devices and the heat release power of the molten salt heat storage device to the superheater.

6. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the reheat device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the reheat device: the input energy of the reheat device comes from the exhaust heat power of the high-pressure steam system; the output energy of the reheat device flows to the input energy of the boiler combustion device; Based on the energy flow relationship of the reheat device, the energy balance model of the reheat device is: the output power of the reheat device is equal to the exhaust steam thermal power of the high-pressure steam device.

7. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the generator device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the generator device: the output energy of the generator device comes from the thermoelectric conversion process of the net heat energy of the high-pressure steam device and the low-pressure steam device respectively; Based on the energy flow relationship of the generator device, the energy balance model of the generator device is: the output power of the generator device is equal to the product of the thermoelectric conversion efficiency of the generator device and the sum of the net thermal energy of the high-pressure steam device and the low-pressure steam device.

8. The hybrid energy storage optimization method according to claim 1, characterized in that: The steps of performing energy flow analysis on the molten salt heat storage device and constructing a corresponding energy balance model include: Analyze the energy flow relationship of the molten salt heat storage device: the heat storage of the molten salt heat storage device comes from the heat storage of the previous period and the charging power of the superheating device and the reheating device; the heat storage of the molten salt heat storage device flows to the superheating device; Based on the energy flow relationship of the molten salt heat storage device, the energy balance model of the molten salt heat storage device is: the heat storage amount between adjacent time periods of the molten salt heat storage device is equal to the sum of the difference between the heat charged and the heat released in the molten salt heat storage device and the heat not lost by the molten salt heat storage device.

9. The hybrid energy storage optimization method according to claim 1, characterized in that: The two-layer optimization configuration model of the hybrid energy storage system is: T cost (x, y) is the optimization objective function of the upper model; cost (x, y) is the optimization objective function of the lower model; x is the decision variable of the upper model; y is the decision variable of the lower model; f(x, y) is the constraint condition of the upper model; g(x, y) is the constraint condition of the lower model; The data model of the upper model is: T cost =I cost +O cost ; Where T cost is the total life cycle cost; cost is the investment cost of the hybrid energy storage system; cost The operating costs of hybrid energy storage systems; The average daily investment cost of the hybrid energy storage system is: Where C in is the average daily investment cost of the hybrid energy storage system; C bat is the average daily investment cost of electrochemical energy storage; C tes is the average daily investment cost of molten salt heat storage; γ is the discount rate; is the unit power cost of electrochemical energy storage; is the unit capacity cost of electrochemical energy storage; T bat is the useful life of electrochemical energy storage; is the rated power of electrochemical energy storage; is the rated capacity of electrochemical energy storage; The unit power cost of molten salt thermal storage; The unit capacity cost of molten salt thermal storage; T tes The service life of molten salt heat storage; is the rated power of molten salt thermal storage; is the rated capacity of molten salt heat storage; The data model of the lower model is: O cost =∑π r C op,r ; Where O cost is the operating cost of the hybrid energy storage system; C op,r is the operating cost of the typical scenario r; π r is the probability of occurrence of typical scenario r; The average daily operating cost for a typical scenario r is: C op =C coal +C carbon +C penalty ; Where C op is the average daily operating cost; C coal is the fuel cost consumed by thermal power units; C carbon is the carbon emission cost of thermal power units; C penalty Penalty costs for curtailing wind and solar power in hybrid energy storage systems; The constraints of the upper model in the two-layer optimization configuration model of the hybrid energy storage system include the rated power and capacity installation restrictions of the hybrid energy storage; the constraints of the lower model include power balance constraints, thermal power unit restriction processing constraints, wind power and photovoltaic power constraints, electrochemical energy storage operation constraints, molten salt heat storage operation constraints and external transmission channel constraints.

10. A hybrid energy storage optimization device considering molten salt heat storage coupled with thermal power units, used for optimizing the configuration of electrochemical energy storage and molten salt heat storage capacity in a hybrid energy storage system, characterized in that: The device comprises: The structural division module is used to analyze the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and divide the molten salt heat storage coupled thermal power unit transformation system into boiler combustion device, high-pressure steam device, medium and low-pressure steam device, superheating device, reheating device, generator device and molten salt heat storage device; An energy flow analysis module is used to analyze the energy flow of each device in the molten salt heat storage coupled thermal power unit transformation system based on the basic structure and energy flow relationship of the molten salt heat storage coupled thermal power unit, and to construct an energy balance model of the corresponding device and corresponding constraints; wherein the energy balance model includes an energy balance model of a boiler combustion device, an energy balance model of a high-pressure steam device, an energy balance model of a medium- and low-pressure steam device, an energy balance model of a superheating device, an energy balance model of a reheating device, an energy balance model of a generator device, and an energy balance model of a molten salt heat storage device; A mathematical model building module is used to build a mathematical model of the corresponding molten salt heat storage coupled thermal power unit transformation system based on the energy balance model of each device; A two-layer optimization model building module is used to analyze the impact of carbon emission trading on the optimal configuration of energy storage, and establish a two-layer optimization configuration model for the corresponding hybrid energy storage system; wherein the two-layer optimization configuration model includes an upper model and a lower model, wherein the decision variables of the upper model are the rated power and rated capacity of the electrochemical energy storage and molten salt heat storage in the hybrid energy storage system, and the objective function is the total life cycle cost, including the hybrid energy storage investment cost and the system operation cost; wherein the decision variables of the lower model are the power generation power of the thermal power unit and the charging and discharging power of the hybrid energy storage, and the objective function is the total operating cost; The solution result output module is used to solve the mathematical model of the molten salt heat storage coupled thermal power unit transformation system and the double-layer optimization configuration model of the hybrid energy storage system using the KKT method, and obtain the optimal configuration strategy of the electrochemical energy storage and molten salt heat storage capacity in the hybrid energy storage system.

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