A source-load-storage resource flexibility supply-demand balance optimization method and device

Abstract

The application discloses a flexible supply-demand balance optimization method and device of a source-load-storage resource. The method comprises the following steps: calculating the flexibility demand of a power system in real time; performing two-stage robust scheduling; wherein, in the first stage, the flue gas diversion ratio of a carbon capture unit and the CO2 rich liquid quantity released by a rich liquid storage tank are used for regulating the operation cost, the carbon trading cost and the flexibility supply capacity; wherein, in the second stage, the flue gas diversion ratio of the carbon capture unit and the CO2 rich liquid quantity released by the rich liquid storage tank are used for regulating the flexibility shortage penalty cost. The carbon capture power plant provides greater flexibility for the supply-demand balance of the power system.

Description

TECHNICAL FIELD

[0001] The application relates to a source-load-storage resource flexibility supply-demand balance optimization method and device. BACKGROUND

[0002] Traditional thermal power plants have a small contribution to the flexibility of the power system. For example, refer to the optimization configuration method considering multi-type flexibility resource collaborative complementation proposed in Chinese invention patent application CN116154863A. Carbon capture power plants can provide greater flexibility, so it is necessary to quantitatively describe the flexibility of carbon capture power plants, and then use it for the scheduling of the power system.

[0003] In addition, the characterization of flexibility demand needs to be improved. For example, Chinese invention patent application CN117937428A proposes a two-stage robust capacity optimization configuration method considering flexibility demand constraints. Since the method is a static resource configuration rather than a dynamic resource scheduling, the characterization of flexibility demand does not consider the uncertainty of the net load at the start period. SUMMARY

[0004] The application provides a source-load-storage resource flexibility supply-demand balance optimization method and device.

[0005] The technical scheme of the application is as follows: a source-load-storage resource flexibility supply-demand balance optimization method, wherein the source end of electric power includes a carbon capture power plant, and the method comprises:

[0006] real-time calculation of the flexibility demand of the power system;

[0007] two-stage robust scheduling;

[0008] In the first stage, the operation parameters of the source end are determined with the first cost as the optimization target and the first constraint as the constraint, the first cost includes the start-stop cost, the operation cost and the carbon trading cost, the first constraint includes the flexibility balance constraint and the rich liquid treatment capacity constraint of the carbon capture power plant, the storage tank liquid balance constraint and the storage tank volume limitation constraint, and the operation parameters of the source end include the flue gas split ratio of the carbon capture unit in the carbon capture power plant and the CO2 rich liquid amount released by the rich liquid storage tank, and the flue gas split ratio of the carbon capture unit and the CO2 rich liquid amount released by the rich liquid storage tank are used to regulate the operation cost, the carbon trading cost and the flexibility supply capacity.

[0009] In the second stage, the operation parameters of the source end are determined with the second cost as the optimization target and the second constraint as the constraint, the second cost includes the flexibility shortage penalty cost, and the second constraint includes the rich liquid treatment capacity constraint of the carbon capture power plant, the storage tank liquid balance constraint and the storage tank volume limitation constraint, and the flue gas split ratio of the carbon capture unit and the CO2 rich liquid amount released by the rich liquid storage tank in the operation parameters of the source end are used to regulate the flexibility shortage penalty cost.

[0010] Optionally, the flue gas split ratio of the s-th carbon capture power plant at time t is denoted as . The amount of CO2 in the CO2-rich liquid released from the rich liquid storage tank at time t by the s-th carbon capture power plant is denoted as […].

[0011] The contribution of the carbon capture unit of the s-th carbon capture power plant to the operating cost of the power system at time t is expressed as: The unit cost of transporting and storing CO2 Let be the amount of CO2 contained in the CO2-rich liquor being processed by the s-th carbon capture power plant at time t. σ cap For capture efficiency, e s Let be the carbon emission intensity of the power generation unit in the s-th carbon capture power plant. Let be the power output of the power generation unit in the s-th carbon capture power plant at time t.

[0012] Optionally, the flue gas split ratio of the s-th carbon capture power plant at time t is denoted as .

[0013] The contribution of the s-th carbon capture power plant to the carbon trading cost at time t is expressed as: The price for carbon emission trading; The free carbon allowance for the s-th carbon capture power plant at time t, Let E be the amount of CO2 captured by the s-th carbon capture power plant at time t. s，t Let be the total carbon emissions of the s-th carbon capture power plant at time t. σ represents the amount of carbon emissions captured by the s-th carbon capture power plant at time t. cap For capture efficiency, e s Let be the carbon emission intensity of the power generation unit in the s-th carbon capture power plant. Let be the power output of the power generation unit in the s-th carbon capture power plant at time t.

[0014] Optionally, the flue gas split ratio of the s-th carbon capture power plant at time t is denoted as . The amount of CO2 in the CO2-rich liquid released from the rich liquid storage tank at time t by the s-th carbon capture power plant is denoted as […]. The upward flexibility provided by the carbon capture unit in the s-th carbon capture power plant at time t is denoted as . The down-flexibility supply provided by the carbon capture unit in the s-th carbon capture power plant at time t is denoted as .

[0015] in Energy consumption of carbon capture unit of the s-th carbon capture power plant at time t, Lower bound of energy consumption of carbon capture unit of the s-th carbon capture power plant, Upper bound of energy consumption of carbon capture unit of the s-th carbon capture power plant;

[0016]

[0017] Fixed energy consumption of carbon capture unit, being negative, Operating energy consumption of carbon capture unit of the s-th carbon capture power plant at time t, being negative, φ is energy consumption of processing unit CO2, σ cap Capture efficiency, e s Carbon emission intensity of power generation unit in the s-th carbon capture power plant, Power output of power generation unit in the s-th carbon capture power plant at time t.

[0018] Optionally, in the first stage and the second stage, the flexibility demand of the power system is determined according to the following formula:

[0019] Wherein, Upward flexibility demand at time t, Downward flexibility demand at time t, Upper bound of fluctuation of net load at time t-1, Lower bound of fluctuation of net load at time t-1, Upper bound of fluctuation of net load at time t, Lower bound of fluctuation of net load at time t.

[0020] Optionally, in the first stage and the second stage, the rich liquid treatment amount constraint is: CO2 amount contained in the CO2 rich liquid amount being treated by the s-th carbon capture power plant at time t, ω is the maximum working coefficient of carbon capture, σ cap Capture efficiency, e s Carbon emission intensity of power generation unit in the s-th carbon capture power plant, Maximum power of power generation unit in the s-th carbon capture power plant.

[0021] Optionally, in the first stage, the storage tank liquid balance constraint is: V s，t Rich liquid volume released by the rich liquid storage tank of the s-th carbon capture power plant, Rich liquid volume of the rich liquid storage tank of the s-th carbon capture power plant at time t, at time t-1, at the initial time of the scheduling decision period, at the end time of the scheduling decision period, respectively, Vtis the lean liquid volume of the lean liquid storage tank of the s-th carbon capture plant at time t, Vt-1is the lean liquid volume of the lean liquid storage tank of the s-th carbon capture plant at time t-1, V0is the lean liquid volume of the lean liquid storage tank of the s-th carbon capture plant at the initial time of the scheduling decision period, Vt+1is the lean liquid volume of the lean liquid storage tank of the s-th carbon capture plant at the end time of the scheduling decision period,

[0022] M is the amount of CO2 contained in the CO2 rich liquid released by the rich liquid storage tank at time t, MEA is the molar mass of the absorbent, q is the molar mass of CO2, re is the stripping amount of the regeneration tower, l R is the absorbent solution concentration, p R is the absorbent solution density.

[0023] The liquid balance constraint of the first stage storage tank is: is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at time t after the second stage adjustment, is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at time t-1 after the second stage adjustment, is the rich liquid volume of the rich liquid storage tank at time t after the second stage adjustment; is the storage amount of the lean liquid storage tank of the s-th carbon capture plant at time t after the second stage adjustment, is the storage amount of the lean liquid storage tank of the s-th carbon capture plant at time t-1 after the second stage adjustment, Vtis the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at the initial time of the scheduling decision period after the second stage adjustment, Vt+1is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at the end time of the scheduling decision period after the second stage adjustment, Vtis the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at the initial time of the scheduling decision period after the second stage adjustment, Vt+1is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at the end time of the scheduling decision period after the second stage adjustment,

[0024] M is the amount of CO2 contained in the CO2 rich liquid released by the rich liquid storage tank at time t after the second stage adjustment, MEA is the molar mass of the absorbent, q is the molar mass of CO2, re is the stripping amount of the regeneration tower, l R is the absorbent solution concentration, p R is the absorbent solution density.

[0025] Optionally, the volume limit constraint of the first stage storage tank is: Vtis the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at time t after the second stage adjustment, Vtis the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at time t after the second stage adjustment, Vt+1is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture plant at the end time of the scheduling decision period after the second stage adjustment, max is the maximum volume of the storage tank;

[0026] The volume restriction constraint of the second stage storage tank is: is the rich liquid amount of the rich liquid storage tank of the s th carbon capture power plant at time t after the second stage adjustment, is the storage amount of the lean liquid storage tank of the s th carbon capture power plant at time t after the second stage adjustment, V max is the maximum volume of the storage tank.

[0027] The technical solution of the present application is as follows: a source-load-storage resource flexibility supply-demand balance optimization device, comprising a memory and a processor, the memory stores a program, and the processor runs the program to execute the above-mentioned method.

[0028] The technical solution of the present application is as follows: a program product, which executes the above-mentioned method when running.

[0029] In the present application, the carbon capture power plant provides greater flexibility for the power system, whether it is the first stage of flexible supply-demand balance or the second stage of flexible supply-demand imbalance, by adjusting the flue gas diversion ratio of the carbon capture unit and the CO2 rich liquid amount released by the rich liquid storage tank, the flexibility supply capacity of the power system can be effectively improved, and the overall economic benefit of the power system is maximized. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the working flowchart of the carbon capture unit of the carbon capture power plant.

[0031] Figure 2 is the flowchart of the source-load-storage resource flexibility supply-demand balance optimization method of the present application.

[0032] Figure 3 is the structural schematic diagram of the source-load-storage resource flexibility supply-demand balance optimization device of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described below in conjunction with specific embodiments, but the protection scope of the present application is not limited thereto.

[0034] Note: The following is a description of the carbon capture power plant as a shutdown unit, it should be understood that it can also be a single generator set in the carbon capture power plant as a shutdown unit. A carbon capture power plant, for example, includes multiple generator sets and includes one carbon capture unit. Multiple generator sets are independently controlled to shut down or start.

[0035] Note: The following shows the design idea and running process of the source-load-storage resource flexibility supply-demand balance optimization method of the present application.

[0036] Note: The concentration of the rich liquid is stable, and the amount of rich liquid released from the rich liquid storage tank (e.g., the volume of rich liquid) is in a proportional relationship with the amount of CO2 contained in the released rich liquid, which is essentially the same parameter to be regulated.

[0037] The carbon capture power plant is split into a power generation unit and a carbon capture unit. The workflow of the carbon capture unit is shown in FIG. 1. Figure 1 .

[0038] All the flue gas generated by the power generation unit is discharged into the carbon capture unit. A part of the flue gas is directly discharged after being cooled by a cooler and then passing through a bypass of the absorption tower. The rest of the flue gas is cooled by the cooler and then pretreated to remove particulate matter, sulfur compounds, and other substances that may interfere with the CO2 capture process. The pretreated flue gas is introduced into the absorption tower, where CO2 reacts with an ethanolamine (MEA, an absorbent) solution to form a rich liquid. The rich liquid is then pumped into the regeneration tower by a rich liquid pump. Excess rich liquid is stored in a rich liquid storage tank. The rich liquid and the lean liquid exchange heat in a heat exchanger. In the regeneration tower, CO2 is released from the rich liquid by heating or reducing the pressure, thereby regenerating the rich liquid and separating CO2. The MEA solution becomes lean liquid after the separation of CO2, and the lean liquid is pumped by a lean liquid pump and then added with absorbent in a mixer to participate in the next CO2 flue gas absorption, thereby realizing recycling. Excess lean liquid is stored in a lean liquid storage tank.

[0039] The ethanolamine in the present application is an example of an absorbent used to capture carbon dioxide in the flue gas. The absorbent reacts chemically with CO2, and then desorbs by heating to release CO2, thereby achieving CO2 capture.

[0040] The operation process of the carbon capture power plant is modeled as follows:

[0041]

[0042] In the formula: Pstis the total power output by the s-th carbon capture power plant at time t; Pstis the power output by the power generation unit in the s-th carbon capture power plant at time t; Cstis the fixed energy consumption of the carbon capture unit in the s-th carbon capture power plant (negative value); Cstis the operating energy consumption of the carbon capture unit in the s-th carbon capture power plant at time t (negative value); φ is the energy consumption per unit of CO2 processed; Cstis the amount of CO2 contained in the amount of CO2 rich liquid being processed by the s-th carbon capture power plant at time t; Cstis the amount of CO2 contained in the amount of CO2 rich liquid released from the rich liquid storage tank of the s-th carbon capture power plant at time t; e s Cstis the carbon emission intensity of the power generation unit in the s-th carbon capture power plant; σcap is the capture efficiency; is the flue gas split ratio of the s-th carbon capture power plant at time t.

[0043] The flexibility supply capability of the carbon capture power plant is modeled as follows:

[0044]

[0045] In the formula: is the upward flexible supply of the s-th carbon capture power plant at time t; is the downward flexible supply of the s-th carbon capture power plant at time t; is the upward flexible supply of the power generation unit of the s-th carbon capture power plant at time t; is the downward flexible supply of the power generation unit of the s-th carbon capture power plant at time t; is the upward flexible supply of the carbon capture unit of the s-th carbon capture power plant at time t, is the downward flexible supply of the carbon capture unit of the s-th carbon capture power plant at time t; is the power of the power generation unit of the s-th carbon capture power plant at time t; is the upper limit of the power of the power generation unit of the s-th carbon capture power plant; is the lower limit of the power of the power generation unit of the s-th carbon capture power plant; is the upward ramping rate of the power generation unit of the s-th carbon capture power plant; is the downward ramping rate of the power generation unit of the s-th carbon capture power plant; Δt is the scheduling length; is the energy consumption (negative value) of the carbon capture unit of the s-th carbon capture power plant at time t; is the upper limit of the energy consumption (negative value) of the carbon capture unit of the s-th carbon capture power plant; is the lower limit of the energy consumption (negative value) of the carbon capture unit of the s-th carbon capture power plant.

[0046] The present application regards the carbon capture power plant as a flexible resource on the power supply side, and further fully excavates the flexibility potential of pumped storage and adjustable load resources, and calls multiple types of flexible resources to meet the flexibility demand. Some embodiments of the present application depict the flexibility supply capability of the power system from the source-load-storage three angles. In other embodiments, the regulation method at the load end and the energy storage end is designed according to other known technologies.

[0047] The power supply side flexibility is mainly provided by the thermal power plant (especially the thermal power plant without carbon capture unit) except the carbon capture power plant; the pumped storage has the advantage of large storage capacity, and has stronger supply capacity for the flexibility of the power system, so it is selected as the energy storage side resource. The power system can control the contracted transferable load users by issuing dispatching instructions, and can transfer the electricity demand of the users to the remaining period to provide flexibility, such as electric vehicles, part of industrial load, etc. The mathematical expression of the flexibility supply capacity of the above-mentioned resources is as follows.

[0048]

[0049] In the formula: is the upward flexibility supply of the thermal power plant i at time t, is the downward flexibility supply of the thermal power plant i at time t; is the power of the thermal power plant i at time t, is the upper limit of the power of the thermal power plant i, is the lower limit of the power of the thermal power plant i, is the upward ramp rate of the thermal power plant i; is the downward ramp rate of the thermal power plant i, and Δt is the dispatching time length.

[0050]

[0051] In the formula: is the upward flexibility supply of the transferable load at time t, is the downward flexibility supply of the transferable load at time t; t TL is the power of the transferable load at time t, is the upper limit of the power of the transferable load, is the lower limit of the power of the transferable load.

[0052]

[0053] In the formula: is the upward flexibility supply of the pumped storage at time t, is the downward flexibility supply of the pumped storage at time t; t PS is the power of the pumped storage at time t (when the value is positive, it indicates power generation, and when the value is negative, it indicates pumping), is the upper limit of the power generation of the pumped storage, is the upper limit of the pumping of the pumped storage; is the storage capacity of the pumped storage at time t, max is the upper limit of the storage capacity of the pumped storage, min is the lower limit of the storage capacity of the pumped storage; η C is the pumping efficiency of the pumped storage, ηD is the generation efficiency of pumped storage power; and Δt is the scheduling time length.

[0054]

[0055] In the formula: is the total upward flexibility supply of the power system at time t, is the total downward flexibility supply of the power system at time t; A G is the number of thermal power plants, A ICCPP is the number of carbon capture power plants, s is the number of carbon capture power plants, and i is the number of thermal power plants.

[0056] Affected by the double uncertainties of new energy generation and load, the net load presents the characteristics of variability and uncertainty. The variability is due to the changes of predicted load demand and new energy generation output, causing the net load to change over time; the uncertainty refers to the prediction deviation of new energy generation and load output, which will cause unpredictable fluctuations of the net load. The system needs to have enough regulation capacity to envelope the fluctuation range of the net load, thus generating flexibility demand.

[0057] The present application assumes that the prediction errors of wind power and load are subject to normal distribution, as shown below:

[0058]

[0059] In the formula: P L，t is the actual power of the load at time t, is the predicted power of the load at time t, δ L，t is the prediction error of the load at time t; P W，t is the actual power of the wind power at time t, is the predicted power of the wind power at time t, δ W，t is the prediction error of the wind power at time t, P W，total is the total installed capacity of wind power. The above 0.03, 1 / 5, 1 / 50 are typical values of the set coefficients, and k, l and m are used to represent these set coefficients, and the formula can be written as the following expression:

[0060]

[0061] Based on the day-ahead prediction values of wind power and load, according to the established probability distribution model, the upward and downward prediction error rates of the output of wind power and load at each time sequence can be sampled to obtain the interval range of the prediction error, and the decision maker can select the confidence level in the [0, 1] interval to adjust the prediction error interval range according to his own risk preference. The embodiment of the present application takes the conservative preference to obtain the prediction error interval with a confidence level of 0.9 to obtain the final prediction error interval:

[0062]

[0063] wherein: is the upper bound of the prediction error of the load at time t, is the lower bound of the prediction error of the load at time t, is the upper bound of the prediction error of the wind power at time t, is the lower bound of the prediction error of the wind power at time t.

[0064] The essence of the flexibility requirement is caused by the uncertainty of the net load. Therefore, before depicting the flexibility requirement, the uncertainty interval of the net load should be depicted first. When the maximum positive deviation of the load and the maximum negative deviation of the wind power occur, the upper limit of the net load is obtained; when the maximum negative deviation of the load and the maximum positive deviation of the wind power occur, the lower limit of the net load is obtained.

[0065]

[0066] wherein: P net，t is the actual value of the net load at time t, is the predicted value of the net load at time t; is the upper limit of the fluctuation of the net load at time t, is the lower limit of the fluctuation of the net load at time t.

[0067] Considering that the flexibility has a directional feature, it can be divided into upward and downward directions. The flexibility requirement is depicted as follows:

[0068]

[0069] wherein: is the upper limit of the fluctuation of the net load at time t-1, is the lower limit of the fluctuation of the net load at time t-1; is the upward flexibility requirement at time t, is the downward flexibility requirement at time t.

[0070] When the upward flexibility requirement and the downward flexibility requirement are determined, both the upper and lower limits of the fluctuation of the net load at the current time and the upper and lower limits of the fluctuation of the net load at the previous time are considered. This processing mode takes into account that the prediction of the net load at the current time and the previous time is uncertain, and guarantees sufficient climbing ability in subsequent real-time dispatching operations.

[0071] In the conventional interval method, the upward flexibility demand at time t is calculated according to the fluctuation upper limit of the net load at time t and the value of the net load at time t-1, and the downward flexibility demand at time t is calculated according to the fluctuation lower limit of the net load at time t and the value of the net load at time t-1. The conventional interval method only considers the uncertainty at the end point (t), and ignores the uncertainty at the start point (t-1), which will lead to the deviation of the calculated flexibility demand interval from the actual demand.

[0072] A source-load-storage two-stage robust optimization scheduling model considering flexibility is established, with the minimum system comprehensive operation cost as the target. In the first stage, the operation state and output of the thermal power plant, carbon capture power plant and pumped storage are obtained in the deterministic scenario according to the day-ahead net load prediction value. In the second stage, based on the optimization result of the first stage, the output of the carbon capture device, pumped storage and transferable load that can quickly respond to the dispatching instruction is adjusted to cope with the uncertain factors in the system, with the minimum adjustment cost as the objective function, considering the “extremely severe scenario” with the largest net load prediction error. Then the result is fed back to the first stage, and the optimal day-ahead scheduling strategy is obtained through iteration.

[0073] The two-stage robust scheduling model takes the minimum total system scheduling cost as the optimization objective, and the optimization objective function is as follows:

[0074]

[0075] In the formula, C total is the total operation cost; f1 is the first stage objective function, f2 is the second stage objective function, V is the uncertainty set, x is the first stage decision variable, and y is the second stage decision variable.

[0076] f1 is the first stage optimization objective, which aims to determine the economic dispatching plan with the minimum operation cost in the deterministic scenario, and the optimization objective includes the start-stop cost, operation cost and carbon trading cost. Since the carbon capture power plant is transformed from the thermal power plant, the cost and constraints of the thermal power plant are also applicable to the carbon capture power plant. In formula (19), s is the number of power plants in the set composed of the thermal power plant and the carbon capture power plant.

[0077]

[0078]

[0079] In the formula, C status is the unit start-stop cost, C OP is the fuel cost, is the carbon trading cost; A s is the total number of carbon capture power plants and thermal power plants, t is time, T is the scheduling decision period, and in the embodiment of the present application, T is 24h, is the start-up cost coefficient of the s-th power plant, is the shut-down cost coefficient of the s-th power plant; is a Boolean variable representing the on-state of the s-th power plant at time t (1 means on, 0 means other states); is a Boolean variable representing the off-state of the s-th power plant at time t (1 means off, 0 means other states); is the power of the generating unit of the s-th power plant at time t; is the start-up cost coefficient of the pumped storage, is the shut-down cost coefficient of the pumped storage; is a state variable representing the power generation state of the pumped storage at time t (1 means power generation, 0 means other states), is a state variable representing the pumping state of the pumped storage at time t (1 means pumping, 0 means other states);a s is the quadratic term coefficient in the power generation cost function of the s-th power plant, b s is the linear term coefficient in the power generation cost function of the s-th power plant, c s is the constant term coefficient in the power generation cost function of the s-th power plant; p e is the pumped hydroelectricity price; is the unit cost of CO2 transportation and storage (e.g. the amount of money spent to handle one ton of CO2); is the carbon emission trading price; is the free carbon quota of the s-th power plant at time t, is the amount of CO2 captured by carbon capture and storage of the s-th power plant at time t (0 for ordinary thermal power plants), E s，t is the total carbon emission of the s-th power plant at time t.

[0080] The first-stage constraints are as follows.

[0081] This is the power balance constraint, the net power output of the source, load and storage resources should be equal to the load.

[0082] This is the flexibility balance constraint, the first stage should ensure that the total supply of flexibility is greater than or equal to the demand for flexibility.

[0083] This is the unit output constraint, the power should be within the limit range.

[0084] This is the unit ramping constraint, the power change amplitude should be within the limit range.

[0085] This is the start-stop time constraint, coal-fired units generally have minimum start-up time and minimum shutdown time. In the formula: t on is the minimum start-up time, t off is the minimum shutdown time, t0 is the time when the unit must be started up and shut down at the initial time, is the state variable of the thermal power unit i at time t, which is 1 when it is started up and 0 when it is shut down. is the state variable of the thermal power unit i at time t-1, which is 1 when it is started up and 0 when it is shut down, is the power of the power generation unit of the s-th carbon capture power plant at t-1, is the power of the thermal power plant i at t-1.

[0086] This is the rich liquid volume constraint of the process, the rich liquid volume being processed cannot be higher than the rich liquid volume generated when the power plant is at maximum output. In the formula: ω is the maximum working coefficient of carbon capture, is the maximum power of the power generation unit in the s-th carbon capture power plant.

[0087] This is the volume expression of the solution released by the rich liquid storage tank of the s-th carbon capture power plant at time t.

[0088] This is the volume expression of the liquid in the rich liquid / poor liquid storage tank at time t; the circulation of rich liquid and poor liquid is considered as a 1:1 relationship, how much rich liquid flows out at time t, how much poor liquid is stored. The storage tank balance expression at the beginning and end of the scheduling period, how much it is at the beginning, it should also be balanced at the end, so that the next scheduling period can be continued.

[0089] This is the volume limit range that the storage tank should be in.

[0090] In the above formula: V s，t is the solution volume spent by the rich liquid storage tank of the s-th carbon capture power plant to release CO2 at time t, M MEA is the molar mass of the absorbent, is the molar mass of CO2, q re is the amount of analysis of the regeneration tower, l R is the concentration of alcohol amine solution, ρ R is the density of alcohol amine solution, is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture power plant at time t, t-1, respectively, is the poor liquid volume of the poor liquid storage tank of the s-th carbon capture power plant at time t, t-1, respectively; is the solution volume of the rich liquid storage tank of the s-th carbon capture power plant at the beginning, V is the solution volume of the lean liquid storage tank of the s-th carbon capture power plant at the beginning time, V is the solution volume of the rich liquid storage tank of the s-th carbon capture power plant at the end time, V is the solution volume of the lean liquid storage tank of the s-th carbon capture power plant at the end time; V max V is the maximum volume of the storage tank.

[0091] This constraint indicates that the pumped storage power is within the limit range.

[0092] This constraint indicates that the pumped storage can only be in one state, either pumping or generating.

[0093]

[0094] This constraint indicates that the pumped storage cannot switch between pumping and generating unlimitedly, and should be within the limit number of times.

[0095] This constraint indicates that the storage capacity of the pumped storage is within the limit range.

[0096] This constraint is the expression for calculating the storage capacity of the pumped storage.

[0097] This constraint indicates that the initial and final storage capacities of the pumped storage should be balanced.

[0098] In the above formula: V is the lower limit of the generating power of the pumped storage, V is the lower limit of the pumping power of the pumped storage, V is the upper limit of the generating power of the pumped storage, V is the upper limit of the pumping power of the pumped storage, V is the generating state variable of the pumped storage at t-1 (taking value 1 indicates being in generating state, and taking value 0 indicates being in other state), V is the pumping state variable of the pumped storage at t-1 (taking value 1 indicates being in pumping state, and taking value 0 indicates being in other state), N j V is the maximum number of start-stop times of the pumped storage within a scheduling decision period, V is the initial inventory of the pumped storage at 0 point, V is the final inventory of the pumped storage at 24 point, V represents the storage capacity of the pumped storage at t, V represents the storage capacity of the pumped storage at t-1, E min , E max V and V are the lower and upper limits of the storage capacity of the pumped storage, respectively.

[0099] Note: The above is an example of scheduling decision cycle for 24h.

[0100] The second stage optimization goal aims to find the most flexible scheduling scheme in an uncertain scenario. The objective function includes flexibility shortage penalty cost, power adjustment cost, and transferable load calling cost. The specific calculation method is as follows.

[0101] f2=C punish +C adjust +C DR (35); indicating that the second stage takes the minimum of penalty cost + adjustment cost + load side scheduling cost as the objective function.

[0102] This is the calculation method of each cost.

[0103] In the above formula: C punish is the flexibility shortage penalty cost, C adjust is the power adjustment cost, C DR is the calling cost of transferable load, c up is the penalty cost coefficient of upward flexibility shortage, c dn is the penalty cost coefficient of downward flexibility shortage, is the upward flexibility shortage at time t, is the downward flexibility shortage at time t, I IC is the compensation cost coefficient of carbon capture power plant, I PS is the compensation cost coefficient of pumped storage, is the adjustment power of the s-th carbon capture power plant at time t in the second stage, ΔP t PS is the adjustment power of pumped storage at time t in the second stage, I TL is the compensation cost coefficient of transferable load, P t TL is the power of transferable load at time t.

[0104] The constraint conditions of the second stage are as follows:

[0105]

[0106] The second stage carries out power readjustment, and this formula is the expression of power rebalancing.

[0107] The second stage may have flexibility shortage, and at this time the flexibility supply + shortage should be greater than or equal to the flexibility demand.

[0108] That is, the rich liquid quantity of readjustment processing is also limited by constraints.

[0109] is the amount of rich liquid released by the rich liquid storage tank of the s-th carbon capture power plant at time t after the second stage adjustment.

[0110] This is the expression of the solution volume in the storage tank after the re-adjustment, etc.

[0111] This is the volume limit constraint of the storage tank after the re-adjustment.

[0112] In the above formula: A ICCPP is the number of carbon capture power plants, is the amount of CO2 contained in the amount of CO2-rich liquid processed by the s-th carbon capture power plant at time t after the second stage adjustment, is the amount of CO2 contained in the amount of rich liquid released by the s-th carbon capture power plant at time t after the second stage adjustment, is the amount of rich liquid in the rich liquid storage tank of the s-th carbon capture power plant at time t after the second stage adjustment, is the amount of rich liquid in the rich liquid storage tank of the s-th carbon capture power plant at time t-1 after the second stage adjustment. is the amount of rich liquid flowing out at time t after the second stage adjustment; is the storage amount of the s-th carbon capture power plant's lean liquid storage tank at time t after the second stage adjustment, is the storage amount of the s-th carbon capture power plant's lean liquid storage tank at time t-1 after the second stage adjustment.

[0113]

[0114] In the formula: P t PS，* is the power of pumped storage at time t after the second stage adjustment, is the inventory of pumped storage at time t after the second stage adjustment, is the inventory of pumped storage at time t-1 after the second stage adjustment.

[0115] Formula (16) is a flexible demand interval considering the uncertainty of the two time points, and formula (21) is a flexible supply and demand balance formula in the day-ahead stage, and through accurate description of flexible demand and supply and demand balance guarantee, the flexible penalty cost in formula (36) can be reduced. The flexible demand interval considering the uncertainty of the starting time and the ending time can accurately describe the net load fluctuation within the allowable error range, and can also avoid the penalty caused by insufficient real-time climbing ability due to the "false balance" of day-ahead flexible supply and demand. The carbon capture power plant is taken as an important provider of flexible supply in the application, the system carbon emission is reduced, and there is no shortage of flexibility, the total dispatching cost is reduced, and the system low carbon and flexibility can be improved together. The two-stage robust optimization model proposed in the application can reduce the compensation cost and penalty cost caused by real-time deviation, and the greater the prediction error, the better the effect. In addition, by changing the uncertain parameters and confidence, the conservativeness of the model can be adjusted, which is beneficial to the decision maker to balance the system operation flexibility, robustness and economy.

[0116] The above wind power is an example of new energy power generation, and new energy power generation may also include solar power generation, which can be mathematically described according to the prior art.

[0117] Reference Figure 2 The above method is summarized as follows: the flexible supply and demand balance optimization method of source-load-storage resources includes: step 101, calculating the flexible demand of the power system in real time; step 102, performing two-stage robust scheduling;

[0118] In the first stage, the operation parameters of the source end are determined with the first cost as the optimization target and the first constraint as the constraint, the first cost includes start-stop cost, operation cost and carbon trading cost, the first constraint includes flexible balance constraint and carbon capture power plant rich liquid treatment capacity constraint, storage tank liquid balance constraint, storage tank volume limitation constraint, and the operation parameters of the source end include the flue gas split ratio of the carbon capture unit in the carbon capture power plant and the CO2 rich liquid amount released by the rich liquid storage tank, and the flue gas split ratio of the carbon capture unit and the CO2 rich liquid amount released by the rich liquid storage tank are used to regulate the operation cost, the carbon trading cost and the flexible supply capacity;

[0119] In the second stage, the operation parameters of the source end are determined with the second cost as the optimization target and the second constraint as the constraint, the second cost includes flexible shortage penalty cost, and the second constraint includes carbon capture power plant rich liquid treatment capacity constraint, storage tank liquid balance constraint, storage tank volume limitation constraint, and the flue gas split ratio of the carbon capture unit and the CO2 rich liquid amount released by the rich liquid storage tank are used to regulate the flexible shortage penalty cost.

[0120] Based on the same inventive concept, the embodiments of the present application also provide a source-load storage resource flexibility supply-demand balance optimization device, comprising a memory and a processor, the memory stores a program, and the processor runs the program to execute the foregoing method.

[0121] The processor is, for example, any type of processor such as a central processing unit (CPU), a graphics processing unit (GPU), etc. The memory is, for example, any type of memory such as a hard disk, a U disk, a flash memory, an optical disk, etc.

[0122] Based on the same inventive concept, the embodiments of the present application also provide a program product which, when executed, performs the foregoing method.

[0123] The various embodiments of the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments.

[0124] The scope of protection of the present application is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various modifications and changes to the present application without departing from the scope and spirit of the present application. If these modifications and changes belong to the scope of the claims of the present application and their equivalent technologies, the intention of the present application also includes these modifications and changes.

Claims

1. A flexible supply-demand balance optimization method for source-load-storage resources, wherein, The source end of the electric power includes a carbon capture power plant, and the method comprises: calculating the flexibility requirement of the electric power system in real time; performing two-stage robust scheduling; wherein, in the first stage, the operation parameters of the source end are determined with the first cost as the optimization target and the first constraint as the constraint, the first cost includes start-stop cost, operation cost and carbon trading cost, and the first constraint includes flexibility balance constraint and rich liquid treatment capacity constraint of the carbon capture power plant, storage tank liquid balance constraint, and storage tank volume limitation constraint, the flexibility balance constraint is that the total upward flexibility supply of the electric power system at time t is greater than or equal to the upward flexibility requirement of the electric power system at time t and the total downward flexibility supply of the electric power system at time t is greater than or equal to the downward flexibility requirement of the electric power system at time t, and the operation parameters of the source end include the flue gas diversion ratio of the carbon capture unit in the carbon capture power plant and the CO2 rich liquid release amount of the rich liquid storage tank, and the flue gas diversion ratio of the carbon capture unit and the CO2 rich liquid release amount of the rich liquid storage tank are used to regulate the operation cost, the carbon trading cost and the flexibility supply capacity; wherein, in the second stage, the operation parameters of the source end are determined with the second cost as the optimization target and the second constraint as the constraint, the second cost includes flexibility shortage penalty cost, and the second constraint includes the rich liquid treatment capacity constraint of the carbon capture power plant, the storage tank liquid balance constraint, and the storage tank volume limitation constraint, and the flue gas diversion ratio of the carbon capture unit and the CO2 rich liquid release amount of the rich liquid storage tank in the operation parameters of the source end are used to regulate the flexibility shortage penalty cost; wherein, the total upward flexibility supply of the electric power system at time t includes the upward flexibility supply of the carbon capture power plant at time t, the upward flexibility supply of the thermal power plant at time t, the upward flexibility supply of the transferable load at time t and the upward flexibility supply of the pumped storage at time t, and the total downward flexibility supply of the electric power system at time t includes the downward flexibility supply of the carbon capture power plant at time t, the downward flexibility supply of the thermal power plant at time t, the downward flexibility supply of the transferable load at time t and the downward flexibility supply of the pumped storage at time t; Upward flexibility supply of the s-th carbon capture power plant at time t Downward flexibility supply of the s-th carbon capture power plant at time t respectively: Provide upward flexibility for the power generation unit of the s-th carbon capture power plant at time t; Downward flexibility supply for the power generation unit of the s-th carbon capture power plant at time t; Provide upward flexibility for the carbon capture unit of the s-th carbon capture power plant at time t. Provide downward flexibility for the carbon capture unit of the s-th carbon capture power plant at time t; Let be the output power of the power generation unit of the s-th carbon capture power plant at time t; Let be the upper limit of the output power of the power generation unit of the s-th carbon capture power plant; This represents the lower limit of the output power of the power generation unit of the s-th carbon capture power plant; Let be the uphill ramp rate of the power generation unit of the s-th carbon capture power plant; Let be the downhill ramp rate of the power generation unit of the s-th carbon capture power plant; Δt is the dispatch duration. Let be the energy consumption of the carbon capture unit of the s-th carbon capture power plant at time t; Let be the upper limit of energy consumption for the carbon capture unit of the s-th carbon capture power plant; Let be the lower limit of energy consumption for the carbon capture unit of the s-th carbon capture power plant; Wherein, the flue gas split ratio of the carbon capture unit in the s-th carbon capture power plant at time t is denoted as The CO2 amount contained in the CO2-rich liquid released by the rich liquid storage tank of the s-th carbon capture power plant at time t is denoted as is the fixed energy consumption of the carbon capture unit, which is negative, is the operation energy consumption of the carbon capture unit of the s-th carbon capture power plant at time t, which is negative, φ is the energy consumption for processing a unit of CO2, σ cap is the capture efficiency, e s is the carbon emission intensity of the power generation unit in the s-th carbon capture power plant; wherein, the upward flexibility requirement and the downward flexibility requirement of the electric power system at time t are determined according to the following formula: wherein, is the upward flexibility demand of the power system at time t, is the downward flexibility demand of the power system at time t, is the upper fluctuation bound of the net load at time t-1, is the lower fluctuation bound of the net load at time t-1, is the upper fluctuation bound of the net load at time t, is the lower fluctuation bound of the net load at time t.

2. The method according to claim 1, characterized in that, The contribution of the carbon capture unit of the s-th carbon capture power plant to the operational cost of the power system at time t is denoted as the cost for transporting and storing the unit CO2, the amount of CO2 contained in the amount of CO2-rich liquid being processed by the s-th carbon capture power plant at time t, 3. The method according to claim 1, characterized in that, The contribution of the s-th carbon capture plant to the carbon trading cost at time t is denoted as is the carbon emission trading price; is the free carbon quota of the s-th carbon capture plant at time t;E s，t is the total carbon emission of the s-th carbon capture plant at time t; denotes the amount of carbon emissions captured by the s-th carbon capture plant at time t.

4. The method of claim 1, wherein, In the first and second stages, the rich liquid treatment amount is constrained as follows: The amount of CO2 contained in the CO2 rich liquid being treated at time t by the s-th carbon capture plant, ω is the maximum working coefficient of carbon capture.

5. The method of claim 1, wherein, The liquid balance constraints of the first stage storage tank are: V s，t is the rich liquid volume released by the rich liquid storage tank of the s-th carbon capture power plant at time t, is the rich liquid volume of the rich liquid storage tank of the s-th carbon capture power plant at time t, time t-1, the initial time of the scheduling decision period, and the end time of the scheduling decision period, in turn, is the lean liquid volume of the lean liquid storage tank of the s-th carbon capture power plant at time t, time t-1, the initial time of the scheduling decision period, and the end time of the scheduling decision period, in turn. M MEA Molar mass of the absorbent, Molar mass of CO2, q re Regeneration column, l R Absorbent solution concentration, p R Absorbent solution density; The liquid balance constraint of the second stage storage tank is: is the rich liquid volume of the rich liquid storage tank of the s th carbon capture power plant after the second stage adjustment at time t, is the rich liquid volume of the rich liquid storage tank of the s th carbon capture power plant after the second stage adjustment at time t-1, is the rich liquid volume of the rich liquid storage tank of the s th carbon capture power plant after the second stage adjustment at time t, is the lean liquid volume of the lean liquid storage tank of the s th carbon capture power plant after the second stage adjustment at time t, is the lean liquid volume of the lean liquid storage tank of the s th carbon capture power plant after the second stage adjustment at time t-1, CO2 amount contained in the CO2 rich liquid amount released by the rich liquid storage tank of the s-th carbon capture power plant at time t after the second stage adjustment.

6. The method of claim 1, wherein, The volume limit constraint of the first stage storage tank is: Vrich,s(t) is the rich liquid volume of the s-th carbon capture power plant at time t, Vlean,s(t) is the lean liquid volume of the s-th carbon capture power plant at time t, V max Vmax is the maximum volume of the storage tank; The volume restriction of the storage tank in the second stage is: is the rich liquid volume of the rich liquid storage tank of the s th carbon capture power plant at time t after the second stage adjustment, is the lean liquid volume of the lean liquid storage tank of the s th carbon capture power plant at time t after the second stage adjustment.

7. A device for optimizing the balance between supply and demand of flexibility of a source-load-storage resource, characterized in that a memory and a processor, the memory stores a program, and the processor runs the program to execute the method in any one of claims 1 to 6.

8. A program product, characterized by The program product comprises a computer program which, when run by a processor, executes the method in any one of claims 1 to 6. The program product comprises a computer program which, when run by a processor, executes the method in any one of claims 1 to 6.

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