Hybrid energy storage optimization method and device considering molten salt heat storage coupled with thermal power unit

Abstract

The application relates to a mixed energy storage optimization method and device considering molten salt heat storage coupled with a thermal power generating unit, which comprises the following steps: analyzing the basic structure and energy flow relationship of the molten salt heat storage coupled with the thermal power generating unit, and dividing the molten salt heat storage coupled with the thermal power generating unit into a system; analyzing the energy flow of each device of the molten salt heat storage coupled with the thermal power generating unit system, and constructing an energy balance model and constraint conditions; constructing a corresponding mathematical model based on the energy balance model of each device; establishing a corresponding double-layer optimization configuration model of the mixed energy storage system; and solving the mathematical model and the double-layer optimization configuration model; the method is based on the internal energy flow relationship of the deep coupling of the molten salt heat storage and the thermal power generating unit, a mathematical model for analyzing the operation of the molten salt heat storage coupled with the thermal power generating unit system is established, the capacity of the electrochemical energy storage and the molten salt heat storage can be reasonably optimized through the model calculation result, different types of energy can be complemented, the flexible adjustment capacity of the system can be improved, and the operation cost of the system can be reduced.

Description

TECHNICAL FIELD

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

[0002] With large-scale development and utilization of Shagehuang new energy base, new energy consumption problem is imminent, and higher requirements are put forward for flexible adjustment resources of power system. Energy storage system has the characteristics of energy time shift, fast response and flexible arrangement, which can effectively improve the adjustment ability of power system, and is the key technology to support power transmission of Shagehuang new energy base. The output of wind and light has the characteristics of randomness and fluctuation, and the difficulty of system daily, medium and short term, long term balance is increased, and single energy storage technology cannot meet the requirements of response speed, energy storage time and other requirements, and a certain scale of daily and above various energy storage forms need to be configured. Hybrid energy storage can meet the application demand of suppressing new energy power fluctuation and promoting large-scale consumption of new energy by coupling energy storage with different technical characteristics. Electrochemical energy storage has the technical characteristics of high energy density and fast response, and the storage time is 2-4 hours, which can smooth the output of new energy and participate in system peak regulation and frequency modulation. It is the most widely used new type of energy storage at present. Molten salt heat storage has large capacity and low cost, and is mainly used in heating and heat supply fields. The heat storage time is 6-15 hours, which can adjust the fluctuation of new energy for a long time, and the molten salt heat storage coupled with coal-fired power generating units can realize peak clipping and valley filling of power grid and improve the deep peak regulation capacity of units. However, at present, molten salt heat storage is only considered in the application scene of photo-thermal power generation, and there is little research on the application scene of coupling with thermal power generating units in Shagehuang new energy base. Most of the existing technologies simulate and analyze molten salt heat storage configuration scheme from the perspective of thermodynamics, and there are few researches on the participation of coal-fired power generating units in system power generation after heat storage modification, and there is lack of mathematical model suitable for system operation angle analysis. This makes it difficult to analyze the system operation process after the modification of molten salt heat storage coupled with thermal power generating units, and it is difficult to accurately configure the capacity of electrochemical energy storage and thermal energy storage. SUMMARY

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

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

[0005] The basic structure and energy flow relationship of molten salt heat storage coupled with thermal power generating units are analyzed, and the molten salt heat storage coupled with thermal power generating unit modification system is divided into a boiler combustion device, a high-pressure steam device, a medium and low-pressure steam device, a superheating device, a reheating device, a generator device and a 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 of the molten salt heat storage coupled thermal power unit reconstruction system is analyzed, and the energy balance model of the corresponding device and the corresponding constraint condition are constructed; wherein the energy balance model includes a boiler combustion device energy balance model, a high-pressure steam device energy balance model, a medium-low pressure steam device energy balance model, a superheating device energy balance model, a reheating device energy balance model, a generator device energy balance model, and a molten salt heat storage device energy balance model;

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

[0008] The influence of carbon emission trading on the optimization configuration of energy storage is analyzed, and a corresponding mixed energy storage system double-layer optimization configuration model is established; wherein the double-layer optimization 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 the molten salt heat storage in the mixed energy storage system, and the target function is the total cost of the whole life cycle, including the investment cost of the mixed energy storage 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 mixed energy storage, and the target function is the total operation cost;

[0009] The mathematical model of the molten salt heat storage coupled thermal power unit reconstruction system and the double-layer optimization configuration model of the mixed energy storage system are solved by using the KKT method, and the optimization configuration strategy of the capacity of the electrochemical energy storage and the molten salt heat storage in the mixed energy storage system is obtained.

[0010] Optionally, the step of analyzing the energy flow of the boiler combustion device and constructing the corresponding energy balance model comprises:

[0011] The energy flow relationship of the boiler combustion device is analyzed: 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-low pressure steam device 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-low pressure steam device.

[0013] Optionally, the step of analyzing the energy flow of the high-pressure steam device and constructing the corresponding energy balance model comprises:

[0014] analyzing 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 for the input power of the extraction of part of the steam 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;

[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 the extraction of part of the steam 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 step of analyzing the energy flow of the medium-low pressure steam device and constructing the corresponding energy balance model comprises:

[0017] analyzing the energy flow relationship of the medium-low pressure steam device: the input energy of the medium-low pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the medium-low pressure steam device is used for the input power of the extraction of part of the steam into the reheating device, the exhaust heat power of the medium-low pressure steam device, and the net heat energy of the medium-low pressure steam device;

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

[0019] Optionally, the step of analyzing the energy flow of the superheating device and constructing the corresponding energy balance model comprises:

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

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

[0022] Optionally, the step of analyzing the energy flow of the reheating device and constructing the corresponding energy balance model comprises:

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

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

[0025] Optionally, the step of analyzing the energy flow of the generator device and constructing the corresponding energy balance model comprises:

[0026] analyzing 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;

[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 heat energy of the high-pressure steam device and the low-pressure steam device.

[0028] Optionally, the step of analyzing the energy flow of the molten salt heat storage device and constructing the corresponding energy balance model comprises:

[0029] analyzing the energy flow relationship of the molten salt heat storage device: the heat storage amount of the molten salt heat storage device comes from the heat storage amount of the previous period and the charging power of the superheating device and the reheating device; the heat storage amount 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 periods of the molten salt heat storage device is equal to the sum of the charging amount and the discharging amount in the molten salt heat storage device minus the heat loss of the molten salt heat storage device.

[0031] Optionally, 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 layer model; O cost (x,y) is the optimization objective function of the lower layer model; x is the decision variable of the upper layer model; y is the decision variable of the lower layer model; f(x,y) is the constraint condition of the upper layer model; g(x,y) is the constraint condition of the lower layer model;

[0034] Wherein the data model of the upper layer model is:

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

[0036] In the formula, T cost is the total cost of the whole life cycle; I cost is the investment cost of the hybrid energy storage system; O cost is the operation cost of the hybrid energy storage system;

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

[0038]

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

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

[0041] O cost =∑π r C op,r ;

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

[0043] The daily average operation cost of the hybrid energy storage system for a typical scenario r is:

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

[0045] In the formula, C op is the daily average operation cost; C coala fuel cost consumed by the thermal power unit; C carbon a carbon emission cost of the thermal power unit; C penalty a wind curtailment and light curtailment penalty cost of the hybrid energy storage system;

[0046] wherein the constraint conditions of the upper model of the hybrid energy storage system double-layer optimization configuration model include hybrid energy storage rated power and capacity installation limits; and the constraint conditions of the lower model include power balance constraints, thermal power unit limit processing constraints, wind power and photovoltaic power constraints, electrochemical energy storage operation constraints, molten salt thermal storage operation constraints, and external transmission channel constraints.

[0047] Further, the application also discloses a hybrid energy storage optimization device considering molten salt thermal storage coupled with a thermal power unit, which is used for optimizing and configuring electrochemical energy storage and molten salt thermal storage capacity in a hybrid energy storage system, and the device comprises:

[0048] a structure division module, which is used for analyzing a basic structure and an energy flow relationship of the molten salt thermal storage coupled with the thermal power unit, and dividing the molten salt thermal storage coupled with the thermal power unit into a boiler combustion device, a high-pressure steam device, a medium-low pressure steam device, a superheating device, a reheating device, a generator device, and a molten salt thermal storage device;

[0049] an energy flow analysis module, which is used for analyzing energy flow of each device of the molten salt thermal storage coupled with the thermal power unit based on the basic structure and the energy flow relationship of the molten salt thermal storage coupled with the thermal power unit, and constructing an energy balance model and corresponding constraint conditions of the corresponding device; wherein the energy balance model includes an energy balance model of the boiler combustion device, an energy balance model of the high-pressure steam device, an energy balance model of the medium-low pressure steam device, an energy balance model of the superheating device, an energy balance model of the reheating device, an energy balance model of the generator device, and an energy balance model of the molten salt thermal storage device;

[0050] a mathematical model construction module, which is used for constructing a mathematical model of the molten salt thermal storage coupled with the thermal power unit based on the energy balance model of each device;

[0051] a double-layer optimization model construction module, which is used for analyzing the influence of carbon emission trading on energy storage optimization configuration, and establishing a corresponding hybrid energy storage system double-layer optimization configuration model; wherein the double-layer optimization configuration model includes an upper model and a lower model, the decision variable of the upper model is rated power and rated capacity of electrochemical energy storage and molten salt thermal storage in the hybrid energy storage system, and the target function is total life cycle cost, including hybrid energy storage investment cost and system operation cost; the decision variable of the lower model is thermal power unit power generation and hybrid energy storage charging and discharging power, and the target function is total operation cost;

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

[0053] Advantages

[0054] The technical solution of the present application has the following advantages:

[0055] (1) The hybrid energy storage optimization method of the present application is based on the internal energy flow relationship of the molten salt heat storage coupled thermal power unit, and a mathematical model for analyzing the operation of the molten salt heat storage coupled thermal power unit retrofit system is established. The deep coupling model has higher precision, and the calculation results are more in line with the actual situation. The model calculation results can be used to reasonably optimize the electrochemical energy storage and the molten salt heat storage capacity, realize the multi-energy complementation of different types of energy, improve the flexible adjustment capability of the system, improve the utilization rate of new energy and the proportion of renewable energy in the power transmission channel, and reduce the operation cost of the system.

[0056] (2) The carbon emission trading mechanism is introduced into the energy storage optimization configuration problem in the hybrid energy storage optimization method of the present application. The carbon emission trading of the thermal power unit can effectively control the carbon emission of the unit in the actual operation of the hybrid energy storage system, and promote the investment and construction subject to improve the carbon asset management capability. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 The figure is a flowchart of the hybrid energy storage optimization method in the embodiments of the present application.

[0058] Figure 2 The figure is a structural schematic diagram of the Shaguo Huang new energy base system in the embodiments of the present application.

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

[0060] Figure 4 The figure is a typical output curve diagram of wind power under the normalized spring, summer, autumn and winter scenes in the embodiments of the present application.

[0061] Figure 5 The figure is a typical output curve diagram of photovoltaic under the normalized spring, summer, autumn and winter scenes in the embodiments of the present application.

[0062] Figure 6 The figure is a structural schematic diagram of the hybrid energy storage optimization device in the embodiments of the present application.

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

[0064] The application will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application. It should be pointed out that the following detailed description is exemplary and is intended to provide further illustration of the application.

[0065] In combination Figure 1 The embodiment of the application specifically discloses a mixed energy storage optimization method considering molten salt heat storage coupled with a thermal power generating unit, which is used for optimizing configuration of electrochemical energy storage and molten salt heat storage capacity in a mixed energy storage system. The embodiment takes a Shaguo Huang new energy base system structure containing mixed energy storage as an example for detailed description, wherein the mixed energy storage is mainly composed of electrochemical energy storage and molten salt heat storage, and the molten salt heat storage is configured in the form of a coupled thermal power generating unit. As shown in the figure, Figure 2 As shown in the figure, the Shaguo Huang 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 an external power transmission channel. The base internally contains two energy flow processes of electricity and heat, wherein the external power transmission demand is mainly met by wind power generation, photovoltaic power generation, thermal power generation and electrochemical energy storage through an extra-high voltage power transmission channel, and the heat energy part is limited to the molten salt heat storage system and the internal circulation of the thermal power generating unit, and does not consider heat supply to the external system. When the new energy output is greater than the power transmission demand, on the one hand, the Shaguo Huang new energy base can absorb the excess new energy through the electrochemical energy storage, and on the other hand, the Shaguo Huang new energy base can reduce the output depth of the peak shaving through the thermal power generating unit coupled with the molten salt heat storage, so as to promote new energy consumption. When the new energy output is less than the power transmission demand, the electrochemical energy storage releases the stored power, and at the same time, the molten salt heat storage releases the stored heat to do work through the boiler and the steam turbine, so as to quickly increase the output of the thermal power generating unit, and fully play the role of peak shaving, especially during the peak summer and peak winter periods.

[0066] In detail, the above-mentioned mixed energy storage optimization method in the embodiment includes the following steps:

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

[0068] The basic structure of the molten salt heat storage coupled with the thermal power generating unit in the embodiment includes four parts of a main unit module, a heat charging module, a heat releasing module and a molten salt heat storage system module, wherein the main unit module includes a boiler, a steam turbine, a condenser and the like; the heat charging module includes a reheating heater, a superheating heater, a phase change heater and a preheating heater; the heat releasing module includes a superheater, an evaporator and a preheater; and 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) ignoring the heat loss of the heat transfer pipeline; 2) ignoring the circulating loss of the molten salt working medium; 3) ignoring the heat transfer loss of water vapor and molten salt. In order to facilitate the description of the internal energy flow relationship of the molten salt heat storage coupled thermal power unit reconstruction system, the molten salt heat storage coupled thermal power unit reconstruction system is further divided 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 reconstruction system is as shown in Figure 3 .

[0070] Step two: 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 of the molten salt heat storage coupled thermal power unit reconstruction system is analyzed, and the energy balance model of the corresponding device and the corresponding constraint condition 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 analyzing the energy flow of the boiler combustion device and constructing the corresponding energy balance model in step two of the embodiment includes:

[0072] The energy flow relationship of the boiler combustion device is analyzed: 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 device 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 device, that is:

[0074]

[0075] wherein P coal,t represents the input power of the boiler combustion device at t period; represents the output power of the superheating device at t period; represents the output power of the reheating device at t period; represents the input power of the high-pressure steam device at t period; represents the input power of the medium and low-pressure steam device at t period.

[0076] In addition, the water vapor of the boiler combustion device needs to satisfy the mass balance:

[0077]

[0078] In the formula: represents the mass of steam output by the superheating device at time t; represents the mass of steam output by the reheating system at time t; represents the mass of steam input into the high-pressure steam system at time t; represents the mass of steam input into the medium-low pressure steam system at time 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 the pulverized coal in the boiler; Q coal represents the calorific value of the pulverized coal combustion; M t represents the mass of the pulverized coal burned by the boiler at time t; and Δt represents the time interval.

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

[0083] M min ≤ M t ≤ M max ;

[0084] In the formula, M min is the minimum mass of the pulverized coal combustion; and M max is the maximum mass of the pulverized coal 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 two of the embodiment includes:

[0086] The energy flow relationship of the high-pressure steam device is analyzed: 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 for extracting part of the steam into 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 that the input power of the high-pressure steam device is equal to the sum of the input power of the extracted steam 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, i.e.,

[0088]

[0089] wherein represents the input power of the extracted steam from the high-pressure steam device into the superheating device at the t period;

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

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

[0092]

[0093] wherein represents the mass of the extracted steam from the high-pressure steam device at the t period; represents the mass of the exhaust steam of the high-pressure steam device at the t period.

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

[0095]

[0096] wherein α hpc represents the coefficient for limiting the exhaust heat power of the high-pressure steam device; represents the lower limit of the net heat energy used by the high-pressure steam device; represents the upper limit of the net heat energy used by the high-pressure steam device.

[0097] (3) The step of performing energy flow analysis on the medium-low pressure steam device and constructing the corresponding energy balance model in step two of the embodiment includes:

[0098] The energy flow relationship of the medium-low pressure steam device is analyzed: the input energy of the medium-low pressure steam device comes from part of the output energy of the boiler combustion device; the output energy of the medium-low pressure steam device is used for the input power of the extracted steam into the reheating device, the exhaust heat power of the medium-low pressure steam device, and the net heat energy of the medium-low pressure steam device;

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

[0100]

[0101] In the formula, W (t) represents the input power of the steam extracted from the medium-low pressure steam device into the reheating device at the t period;

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

[0103]

[0104] In the formula, m (t) represents the mass of the steam extracted from the medium-low pressure steam device at the t period;

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

[0106]

[0107] In the formula, a represents the coefficient for limiting the exhaust heat power of the medium-low pressure steam device; mlpc

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

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

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

[0111]

[0112] In the formula, Qsh(t) represents the heat release power of the molten salt heat storage device to the superheating device at the t period.

[0113] It should be noted that the water vapor of the superheating device in the embodiment should satisfy the mass balance:

[0114]

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

[0116]

[0117] In the formula, βsh represents the limit coefficient of the output power of the superheating device. su

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

[0119] The energy flow relationship of the reheating device is analyzed: the input energy of the reheating device comes from the exhaust steam heat power of the high pressure steam system; and the output energy of the reheating device flows to the input energy of the boiler combustion device.

[0120] Based on the energy flow relationship of the reheating device, the energy balance model of the reheating device is that the output power of the reheating device is equal to the exhaust steam heat power of the high pressure steam device, i.e.,

[0121]

[0122] Further, the reheating device should satisfy the mass balance:

[0123]

[0124] In addition, the output power of the reheating device and the exhaust steam heat power of the high pressure steam device should be limited:

[0125]

[0126] In the formula, βrh represents the limit coefficient of the output power of the reheating device.​​​​re a coefficient representing the limit of the output power of the reheating device; a coefficient representing the minimum thermal power of the exhaust steam of the high-pressure steam device; a coefficient representing the maximum thermal power of the exhaust steam of the high-pressure steam device.

[0127] (6) The step of analyzing the energy flow of the generator device and constructing the energy balance model of the generator device in the second step of the embodiment includes:

[0128] analyzing the energy flow relationship of the generator device: the output energy of the generator device is from the thermoelectric conversion process of the net thermal energy of the high-pressure steam device and the low-pressure steam device;

[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 thermal energy of the high-pressure steam device and the low-pressure steam device, that is:

[0130]

[0131] In the formula, P g,t represents the output power of the generator at time t; η g represents the thermoelectric conversion efficiency.

[0132] (7) The step of analyzing the energy flow of the molten salt heat storage device and constructing the corresponding energy balance model in the second step of the embodiment includes:

[0133] Analyzing the energy flow relationship of the molten salt heat storage device: the heat storage amount of the molten salt heat storage is not only related to the charging and discharging power, but also related to the heat storage amount of the previous period and the heat loss. The heat storage amount of the molten salt heat storage device comes from the heat storage amount of the previous period and the charging power of the superheating device and the reheating device; the heat storage amount of the molten salt heat storage device flows to the superheating device;

[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 periods of the molten salt heat storage device is equal to the sum of the difference between the charging amount and the discharging amount in the molten salt heat storage device and the non-heat loss amount of the molten salt heat storage device, that is:

[0135]

[0136] In the formula, E tes,t and E tes,t-1 respectively represent the heat storage amount of the molten salt heat storage device at time t and time t-1; represents the heat loss rate of the molten salt heat storage device; represents the charging power of the molten salt heat storage device from the superheating device and the reheating device at time t; and respectively represent the charging and discharging efficiency of the molten salt heat storage device.

[0137] where the discharging power of the molten salt heat storage is:

[0138]

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

[0140]

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

[0142]

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

[0144] Step three: based on the energy balance model of each device, a mathematical model of the molten salt heat storage coupled with the power plant reconstruction system is constructed; in this step three, by simultaneously solving the above 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 constraint conditions, the mathematical model of the molten salt heat storage coupled with the power plant reconstruction system is obtained.

[0145] Step four: analyze the influence of carbon emission trading on the optimal configuration of energy storage, and establish a corresponding double-layer optimization configuration model of the hybrid energy storage system; wherein the double-layer optimization 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 the molten salt heat storage in the hybrid energy storage system, and the objective function is the total cost of the whole life cycle, including the investment cost of the hybrid energy storage and the system operation cost; the decision variables of the lower model are the power generation power of the power plant and the charging and discharging power of the hybrid energy storage, and the objective function is the total operation 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; O 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 above-mentioned double-layer optimization configuration model includes two levels of optimization tasks, and the lower running optimization is nested in the upper configuration optimization, and the upper configuration result provides boundary conditions for the lower running optimization.

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

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

[0151] In the formula, T cost is the total life cycle cost; I cost is the investment cost of the hybrid energy storage system; O cost is the operation cost of the hybrid energy storage system;

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

[0153]

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

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

[0156] O cost = Σπ r C op,r ;

[0157] In the formula, Ocost is the operation cost of the hybrid energy storage system; C op,r is the operation cost of the typical scenario r; π r is the probability of the typical scenario r;

[0158] The daily average operation cost of a typical scenario r is:

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

[0160] In the formula, C op is the daily average operation cost; C coal is the fuel cost consumed by the thermal power unit; C carbon is the carbon emission cost of the thermal power unit; C penalty is the wind and light curtailment penalty cost of the hybrid energy storage system.

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

[0162]

[0163] In the formula, λ coal represents the unit coal price; M t,i represents the mass of pulverized coal consumed by the thermal power unit i at the t period; 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; λ pv represents the unit light curtailment cost; represents the wind curtailment output at the t period; represents the light curtailment output at the t period.

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

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

[0166] In the formula, C carbon,t is the carbon emission right trading cost of the thermal power unit at the t period; λ carbon is the carbon emission right trading price coefficient; D carbon,t is the actual carbon emission amount of the thermal power unit at the t period; D ini,t is the carbon emission quota of the thermal power unit at the t period.

[0167] The constraint conditions of the upper model of the mixed energy storage system double-layer optimization configuration model include mixed energy storage rated power and capacity installation limit; the constraint conditions of the lower model include power balance constraint, thermal power unit limit processing constraint, wind power and photovoltaic power constraint, electrochemical energy storage operation constraint, molten salt heat storage operation constraint, and external sending channel constraint.

[0168] The mixed energy storage rated power constraint includes:

[0169]

[0170] In the formula, respectively represent the minimum and maximum values of the rated power of the electrochemical energy storage and the molten salt heat storage; respectively represent the minimum and maximum values of the rated capacity of the electrochemical energy storage and the molten salt heat storage.

[0171] Further, the power balance constraint includes:

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

[0173] In the formula, P wp,t represents the actual output of wind power generation at the t period; P pv,t represents the actual output of photovoltaic power generation at the t period; P bat,t represents the electrochemical energy storage charging and discharging power at the t period; P dc,t represents the direct current external sending power at the t period.

[0174] The thermal power unit limit output constraint includes:

[0175] Thermal power unit output boundary condition:

[0176] Thermal power unit climbing rate limit:

[0177] In the formula, represents the rated power of the thermal power unit; represents the load shedding rate of the thermal power unit; represents the output climbing rate of the thermal power unit.

[0178] The wind power and photovoltaic power constraint includes:

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

[0180]

[0181] In the formula, 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 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 at time 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 represents the amount of electrochemical energy stored 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 initial state and the end state of the electrochemical energy storage are subject to the energy storage power constraint:

[0198] In the formula represents the energy storage power of the initial state; represents the energy storage power of the end state.

[0199] The molten salt heat storage operation constraint includes:

[0200] The charging and discharging power constraint:

[0201] In the formula P tes,t represents the charging and discharging power of the molten salt heat storage at t.

[0202] The initial state and the end state of the molten salt heat storage are subject to the heat storage capacity constraint:

[0203] In the formula represents the heat storage capacity of the initial state; represents the heat storage capacity of the end state.

[0204] The delivery channel constraint includes:

[0205] The delivery channel power boundary condition is:

[0206] In the formula and are the lower limit and the upper limit of the system delivery channel power, respectively.

[0207] The delivery power channel power constraint is:

[0208] In the formula ζ represents the proportion of renewable energy power in the delivery power channel.

[0209] Step five: the KKT method is used to solve the mathematical model of the molten salt heat storage coupled with the thermal power unit reconstruction system and the double-layer optimization configuration model of the hybrid energy storage system, and the optimization configuration strategy of the electrochemical energy storage and the molten salt heat storage capacity in the hybrid energy storage system is obtained. In this application, the above-mentioned mathematical model of the molten salt heat storage coupled with the thermal power unit reconstruction system and the double-layer optimization configuration model of the hybrid energy storage system jointly constitute the hybrid energy storage optimization configuration model of Shaguo Barren New Energy Base in this embodiment. It can be known from the analysis of the double-layer optimization model that the lower layer optimization problem is a continuously differentiable convex function, and the KKT method can be used to convert the double-layer optimization problem into a single-layer optimization problem for solving. The single-layer model after conversion belongs to a mixed integer linear programming problem, and in this embodiment, the MATLAB-2024a platform is programmed to use the YALMIP tool package to call the CPLEX mathematical optimization solver for solving.

[0210] Further, the present embodiment takes a large new energy base in Ordos of Inner Mongolia Autonomous Region as an example, and verifies the optimization configuration of the energy storage power and capacity in the system by using the above method. The system includes photovoltaic power generation of 8000 MW, wind power generation of 4000 MW, 4 single-machine capacity of 1000 MW thermal power units, supporting a certain proportion of energy storage projects, newly built Ordos to central and eastern regions 1 return ± 800 kV UHV DC transmission project with a maximum power transmission capacity of 8000 MW, which meets the green and low-carbon energy consumption demand of the receiving end area. The present embodiment selects the wind power generation and photovoltaic power generation data of four typical days of spring, summer, autumn and winter based on the historical data of the wind and light field station in the Kubuqi Desert area of Inner Mongolia Autonomous Region, and simulates and analyzes the reconstructed 96-hour output curve, and obtains the annual investment and operation cost of the energy storage according to the probability weighting of the scene. As shown in Figure 4 and 5 , which is the normalized wind and light output curve diagram of the typical day of spring, summer, autumn and winter.

[0211] The present embodiment compares and analyzes three scenes: scene 1 (basic scene) Shagehuang new energy base supporting only single electrochemical energy storage; scene 2 (ideal scene) Shagehuang new energy base supporting electrochemical energy storage and molten salt heat storage two kinds of energy storage, molten salt heat storage and thermal power unit are ideal simple combination under the condition, ignoring the ideal model of the coupling relationship of thermal power unit; scene 3 (coupling scene) Shagehuang new energy base supporting electrochemical energy storage and molten salt heat storage two kinds of energy storage, and considering the deep coupling condition of thermal power unit molten salt heat storage transformation, that is, the method proposed in the present application. The mixed energy storage optimization configuration results of Shagehuang new energy base under each scene are shown in Table 1:

[0212] Table 1

[0213]

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

[0215] In terms of economic cost, the total annual cost of the basic scenario is the highest, which is 1.57 million yuan and 0.89 million yuan higher than that of the ideal scenario and the coupling scenario, with an increase of 2.3% and 1.3% respectively. The annual fuel cost and the annual carbon emission cost of the thermal power unit in the basic scenario are the highest, and the cost of abandoned wind and light is also the highest. After the base is coupled with the thermal power unit by molten salt heat storage, the peak shaving potential of the thermal power unit is fully tapped, and the flexibility of the thermal power unit is improved, so that the minimum output of the thermal power unit is further reduced. At the same time, during the peak period of power consumption at the receiving end, the thermal power unit can rely on the energy released by the molten salt heat storage and the boiler combustion to meet the load demand, thereby reducing the coal combustion and the carbon emission. After the base is equipped with electrochemical energy storage and molten salt heat storage, although the investment cost increases, the operation cost significantly decreases. Compared with the basic scenario, the investment cost of the ideal scenario and the coupling scenario increases by 0.79 million yuan and 2.34 million yuan, with an increase of 4.2% and 12.6% respectively, and the operation cost of the ideal scenario and the coupling scenario decreases by 2.36 million yuan and 3.24 million yuan, with a decrease of 4.8% and 6.6% respectively. In addition, the coupling scenario can fully utilize the wind and light resources and reduce the cost of abandoned wind and light, and the utilization rate of new energy and the proportion of renewable energy in the basic scenario can be increased by at least about 1%. In summary, the mathematical modeling of the molten salt heat storage coupled with the thermal power unit can improve the accuracy of the model to some extent, which not only can realize the complementary advantages of multiple types of energy storage, but also can effectively improve the economy of the base.

[0216] At the same time, the thermal power unit coupled with the molten salt heat storage can flexibly participate in system peak shaving and new energy consumption, reduce the cost of abandoned wind and light, and the connected new energy will replace the thermal power start-up capacity, further reduce the fuel cost required by the boiler combustion, and overall, the increase amplitude of the annual carbon emission cost of the base is less than the decrease amplitude of the cost of abandoned wind and light and the annual fuel cost, so the total operation cost of the base presents a downward trend.

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

[0218] a structure division module, which is used for analyzing the basic structure and energy flow relationship of the molten salt heat storage coupled with the thermal power unit, and dividing the molten salt heat storage coupled with the thermal power unit into a boiler combustion device, a high-pressure steam device, a medium-low pressure steam device, a superheating device, a reheating device, a generator device and a molten salt heat storage device;

[0219] An energy flow analysis module is configured to analyze energy flow of each device of the molten salt heat storage coupled thermal power unit retrofit system based on 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 constraint conditions; wherein the energy balance model comprises 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-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 construction module is configured to construct a mathematical model of the molten salt heat storage coupled thermal power unit retrofit system based on the energy balance model of each device.

[0221] A double-layer optimization model construction module is configured to analyze the influence of carbon emission trading on energy storage optimization configuration, and to establish a double-layer optimization configuration model of the hybrid energy storage system; wherein the double-layer optimization configuration model comprises an upper-layer model and a lower-layer model, the decision variable of the upper-layer model is rated power and rated capacity of the electrochemical energy storage and the molten salt heat storage in the hybrid energy storage system, and the target function is total life cycle cost including hybrid energy storage investment cost and system operation cost; the decision variable of the lower-layer model is power generation of the thermal power unit and power of the hybrid energy storage charging and discharging, and the target function is total operation cost.

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

[0223] The device provided by the embodiment of the present application can realize Figure 1 The method embodiment realizes various processes, and details are not repeated here to avoid repetition.

[0224] As Figure 7 indicated, the embodiment of the present application further provides an electronic device, which comprises a processor and a memory, a program or instructions stored on the memory and executable on the processor, and the program or instructions are executed by the processor to realize various processes of the method embodiment as Figure 1 indicated and achieve the same technical effects, and details are not repeated here to avoid repetition.

[0225] The embodiment of the present application further provides a readable storage medium, which stores a program or instructions, and the program or instructions are executed by the processor to realize various processes of the method embodiment as Figure 1 indicated and achieve the same technical effects, and details are not repeated here to avoid repetition.

[0226] The embodiment of the present application further provides a computer program product, comprising computer instructions, which, when executed by a processor, implement the above-mentioned Figure 1 The various processes of the method embodiment are implemented, and the same technical effects can be achieved. To avoid repetition, they will not be described here.

[0227] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the 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 the processes should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. The sequence number of the above-mentioned embodiments of the present application is only for description, not representing the pros and cons of the embodiments.

[0228] It should be noted that in this paper, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a…" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0229] In several embodiments provided by 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, and actual implementation can have another division manner, 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 or direct coupling or communication connection between the various components shown or discussed can be through some interface, indirect coupling or communication connection between devices or units, which can be electrical, mechanical or other forms.

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

[0231] In addition, all the functional units in the embodiments of the present application can be integrated in one processing unit, or each unit can be a separate unit, or two or more units can be integrated in one unit; the integrated unit can be realized in the form of hardware, or in the form of hardware plus software function unit.

[0232] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by relevant hardware instructed by programs. The aforementioned programs can be stored in a computer readable storage medium, and when the programs are executed, the steps of the above-mentioned method embodiments are executed. The aforementioned storage medium includes mobile storage devices, read-only memory (ROM), magnetic discs or optical discs, and various media that can store program codes.

[0233] Alternatively, when the integrated units of the present application are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application can be embodied in the form of software products, and the computer software products are stored in a storage medium, including a number of instructions to make a device (which can be a terminal or a platform) execute all or part of the methods described in the embodiments of the present application. The aforementioned storage medium includes mobile storage devices, ROM, magnetic discs or optical discs, and various media that can store program codes.

[0234] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be regarded as the protection scope 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 the 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 were analyzed, and the molten salt heat storage coupled thermal power unit transformation system was divided into a boiler combustion unit, a high-pressure steam unit, a medium- and low-pressure steam unit, a superheating unit, a reheating unit, a generator unit, and a molten salt heat storage unit. 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 emissions trading on the optimal configuration of energy storage and establish a corresponding two-layer optimization configuration model for the hybrid energy storage system; 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 thermal 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 charge and discharge 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 two-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 devices: the input energy of the medium and low pressure steam devices comes from part of the output energy of the boiler combustion device; the output energy of the medium and low pressure steam devices is used to extract part of the steam to enter the input power of the reheat 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; 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 sum of 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 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; 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 heat 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 superheater and reheater; the heat storage of the molten salt heat storage device flows to the superheater; 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 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; I 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 service 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 a boiler combustion unit, a high-pressure steam unit, a medium- and low-pressure steam unit, a superheating unit, a reheating unit, a generator unit, and a molten salt heat storage unit; 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 and corresponding constraint conditions for the corresponding device; 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; 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 construction module is used to analyze the impact of carbon emissions 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 thermal 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; wherein the decision variables of the lower model are the power generation power of the thermal power unit and the charge and discharge 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 two-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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