Optimized dispatching method for ammonia-doped combustion, pumped storage and wind power combined power generation system

Abstract

The invention belongs to a micro-grid dispatching operation method, and relates to an optimized dispatching operation method for an ammonia-doped combustion, pumped storage and wind power combined power generation system. The method comprises the following steps: constructing an optimized dispatching operation model of ammonia-doped combustion, pumped storage and wind-power combined power generation; a target function of the optimal scheduling operation model comprises a combustion stability penalty term related to an ammonia doping ratio gamma t of the thermal power generating unit; the constraint condition of the optimal scheduling operation model comprises the constraint condition of an ammonia doping ratio gamma t; and solving the optimal scheduling operation model through a target function in constraint conditions, and solving the optimal ammonia doping proportion under the constraint conditions of the ammonia doping proportion gamma t in the solving process so as to maximize the fuel cost reduction rate. According to the method, various constraint conditions are set to cope with the complex factors, and therefore it is guaranteed that the combined power generation system can stably and efficiently operate under various conditions.

Description

Technical Field

[0001] The present invention belongs to the dispatching of microgrid dispatching operation methods, and is an optimized dispatching operation method for an ammonia-combined combustion, pumped-storage, and wind power combined power generation system. Background Art

[0002] In the context of the global active promotion of energy transformation and sustainable development, reducing dependence on traditional fossil fuels and increasing the proportion of renewable energy in the energy structure have become key measures to address climate change and energy crises. As a clean and renewable energy source, wind energy has witnessed rapid development globally in recent years, with the installed capacity continuously climbing. However, wind power has significant characteristics of intermittency, volatility, and unpredictability, which pose great challenges to the stable power supply of the power system.

[0003] Pumped-storage energy storage, as a mature large-scale energy storage technology, can effectively regulate the power supply and demand balance and improve the stability and reliability of the power system by pumping water from the lower reservoir to the upper reservoir to store energy during power surplus and releasing water for power generation during power shortage. However, the combination of single pumped-storage and wind power still has certain limitations in coping with complex and changing power demands. At the same time, ammonia-combined combustion technology, as a new combustion method, has gradually come into people's view. Ammonia (NH3), as a hydrogen-containing compound with a high hydrogen content, produces almost no carbon dioxide emissions during combustion and is a promising low-carbon or even zero-carbon fuel. Introducing ammonia-combined combustion technology into the power generation system can not only reduce the use of traditional fossil fuels and lower carbon emissions but also provide a more flexible energy supply method for the power generation system.

[0004] Therefore, organically combining ammonia-combined combustion, pumped-storage, and wind power to form a combined power generation system and optimizing its dispatching operation are of great significance for improving energy utilization efficiency, ensuring the stable and reliable operation of the power system, and achieving sustainable energy development goals. However, the current optimized dispatching operation method for this new combined power generation system is still in the exploratory stage, and in-depth research is urgently needed to solve a series of key problems such as system coordinated operation and energy optimal allocation. Summary of the Invention

[0005] The purpose of the present invention is to provide an optimized dispatching operation method for an ammonia-combined combustion, pumped-storage, and wind power combined power generation system to solve the technical problems raised in the above background art.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an optimized dispatching method for an ammonia-combined combustion, pumped-storage, and wind power combined power generation system, which includes:

[0008] Construct an optimal dispatching operation model for ammonia - doped combustion, pumped - storage energy, and wind - power combined power generation;

[0009] The objective function of the optimal dispatching operation model includes a combustion stability penalty term related to the ammonia - doping ratio γ of the thermal power unit; t Related combustion stability penalty term;

[0010] The constraint conditions of the optimal dispatching operation model include the constraint conditions of the ammonia - doping ratio γ; t Constraint conditions;

[0011] Solve the optimal dispatching operation model through the objective function within the constraint conditions. During the solution process, solve for the optimal ammonia - doping ratio under the constraint conditions of the ammonia - doping ratio γ to maximize the fuel - cost reduction rate. t Under the constraint conditions of the ammonia - doping ratio γ, solve for the optimal ammonia - doping ratio to maximize the fuel - cost reduction rate.

[0012] As a preferred embodiment, the calculation formulas for the combustion stability penalty term and the ammonia - doping ratio are as follows:

[0013]

[0014] 0 ≤ γ t ≤ γ max

[0015]

[0016] Among them, C stab Represents the combustion stability penalty term, γ t Represents the ammonia - doping ratio, γ safe Is the safety threshold, k is the penalty coefficient, And Q coal Are the lower calorific values of ammonia and coal respectively; a1, b1, and c1 are the consumption characteristic coefficients of the thermal power unit; P t th ,th Is the output power of the thermal power unit at time t; And Are the coal consumption and ammonia - doping amount of the thermal power unit at time t respectively, γ max Is the maximum allowable ammonia - doping ratio, and α is the ammonia - coal calorific value equivalent substitution factor.

[0017] As a preferred embodiment, the method further includes:

[0018] When the ammonia - doping ratio is greater than the safety threshold, increase the minimum output of the thermal power unit to a preset proportion of the rated value;

[0019] When the ammonia - doping ratio is equal to the maximum allowable ammonia - doping ratio, compensate through a correction coefficient, and the formula is expressed as:

[0020]

[0021] In the formula, k η represents the correction coefficient.

[0022] As a preferred embodiment, the constraint conditions of the optimal scheduling operation model further include multi - energy ramping coordination constraints, which are expressed as:

[0023]

[0024] In the formula, P t th,th is the output power of the thermal power unit at time t, and Pte represents the power generation power of the pumped - storage power station at time t.

[0025] As a preferred embodiment, the objective function of the optimal scheduling operation model is expressed as:

[0026]

[0027]

[0028] Among them, C represents the total cost; C wt represents the wind power operation cost; C pv represents the photovoltaic power operation cost; C ab represents the curtailment of wind and solar power cost; C th represents the operation cost of the coal - fired unit; represents the carbon emission cost; C ep represents the environmental cost; P t wt 、P t pv 、P t ab 、P t th 、 P t ep respectively represent the power output of the corresponding system at time t; Δt represents the time interval; and are the operation costs of the thermal power unit and the combined heat and power unit respectively;

[0029] As a preferred embodiment, the operation cost of the combined heat and power unit

[0030]

[0031] In the formula: is the coal consumption of the combined heat and power unit at time t; a2, b2, c2 and c ν1 are the characteristic coefficients of the combined heat and power unit; and are the electric power and heat power output by the cogeneration unit in period t, respectively;

[0032] The operating cost of the thermal power unit is calculated as follows:

[0033] When the thermal power unit is in the RPR stage, the loss cost of the thermal power unit is negligible. When the thermal power unit is in the DPR stage, the calculation formula for the operating cost of the thermal power unit is:

[0034]

[0035] where τ1 and τ2 are the operating loss coefficients in the DPR1 and DPR2 stages; c unit is the unit construction cost of the unit; is the loss cost of the thermal power unit in period t, c coal is the unit price of coal.

[0036] As a preferred embodiment, the carbon emission cost is calculated by the formula:

[0037]

[0038] where: e G and e H are the carbon emission quotas per unit of power supply and the carbon emission electricity quotas per unit of heat supply, respectively; E is the carbon emission right quota; is the CO2 emission in period t; is the amount of CO2 emitted per unit of coal combustion; c e is the carbon emission quota penalty cost coefficient;

[0039] The environmental cost C ep is calculated as follows:

[0040]

[0041] where: J is the type of taxable pollutant; K is the tax amount payable per pollution equivalent; m j is the mass of the j-th pollutant generated per unit of coal combustion; η j is the removal efficiency of the j-th pollutant by the environmental protection device; G j is the pollution equivalent of the j-th pollutant.

[0042] As a preferred embodiment, the improved mixed-integer second-order cone programming (MI-SOCP) algorithm is used to solve the optimal dispatching operation model, in which the ammonia blending ratio and the output of the thermal power unit are combined into an equivalent coal consumption variable to reduce the dimension of the decision variables, expressed as:

[0043]

[0044] represents the equivalent coal consumption variable.

[0045] As a preferred embodiment, the calculation formula of the fuel cost reduction rate is:

[0046]

[0047] where c coal represents the unit price of coal.

[0048] As a preferred embodiment, the ammonia blending ratio γ t is solved using a hierarchical solution strategy. The outer loop uses a genetic algorithm to solve the integer combination of the ammonia blending ratio γ t with both the population size and the number of iterations preset. The inner loop performs continuous variable optimization on the fixed ammonia blending ratio γ t combination by calling the CPLEX solver, calculates the objective function value of the optimized scheduling operation model, and determines the optimal ammonia blending ratio γ t .

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention uses an optimized scheduling method to improve the operating efficiency of the ammonia combustion, pumped storage, and wind power combined power generation system on the premise of considering various complex factors, and details the characteristics of various power generation equipment and energy conversion links in the combined power generation system. During the implementation process, since the change in the ammonia combustion ratio will change the combustion conditions and power generation efficiency of thermal power units, the present invention introduces an ammonia-coal calorific value equivalent substitution factor and the treatment methods of thermal power units under different ammonia blending ratios, and sets various constraint conditions to cope with these complex factors, so as to ensure the stable and efficient operation of the combined power generation system under various conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is the optimized scheduling energy flow schematic diagram of the ammonia combustion - pumped storage - wind power combined power generation system in the present invention;

[0052] Figure 2 is the ammonia combustion schematic diagram in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0054] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0055] Embodiment 1

[0056] Combined with Figure 1 , it is pre-explained that the energy flow relationship of the integrated energy system applied in this embodiment includes: the integrated energy system is supplied with energy through the superior power grid, ammonia-doped combustion of thermal power units, and new energy power generation. The energy input on the source side meets the load demand through the internal coupling equipment of the system. The cogeneration unit on the source side generates electricity, and a part of the thermal power generated by the gas turbine is supplied to the heat load through the waste heat boiler, and the other part is used for power generation to supply the electrical load, realizing the thermoelectric flexibility of cogeneration. The pumped storage is used as a storage unit to further increase the system flexibility. The schematic diagram of the principle of ammonia-doped combustion is as Figure 2 .

[0057] This embodiment provides an optimized dispatching operation method for an ammonia-doped combustion, pumped storage, and wind power combined power generation system, which includes:

[0058] Step S1, constructing an optimized dispatching operation model for ammonia-doped combustion, pumped storage, and wind power combined power generation; the objective function of the optimized dispatching operation model includes the ammonia doping ratio γ of the thermal power unit tThe related combustion stability penalty term; the constraint conditions of the optimized scheduling operation model include the ammonia blending ratio γ t constraint conditions;

[0059] The objective function expression of the optimized scheduling operation model for the ammonia combustion - pumped storage combined power generation system is:

[0060]

[0061] where C represents the total cost; C wt represents the operating cost of wind power; C pv represents the operating cost of photovoltaic power; C ab represents the cost of curtailed wind and solar power; C th represents the operating cost of coal - fired units; represents the carbon emission cost; C ep represents the environmental cost; P t wt 、P t pv 、P t ab 、P t th 、 P t ep respectively represent the power output of the corresponding system at time t; Δt represents the time interval.

[0062] According to the operating characteristics of coal - fired units, the operating costs (fuel cost and loss cost) of thermal power units and the operating costs (fuel cost) of cogeneration units are calculated respectively. Then the operating cost of coal - fired units is

[0063]

[0064] In the formula and are the operating costs of thermal power units and cogeneration units respectively.

[0065] The combustion stability penalty term is expressed as:

[0066]

[0067] where γ safe = 15% is the safety valve value, and k is the penalty coefficient. When γ t > 15%, the minimum output of thermal power units is forced to increase to 50% of the rated value (originally 30%) to avoid excessive NOx caused by insufficient ammonia combustion under low - load conditions; when γ t = 20%, the boiler efficiency drops by about 2.3%, which is compensated by the correction coefficient k η = 0.977, that is

[0068]

[0069] For a thermal power unit with the technical transformation of ammonia-doped combustion, ammonia enters the boiler by replacing part of the pulverized coal at a certain heat ratio, and the actual coal consumption of the thermal power unit is:

[0070]

[0071] In the formula: a1, b1, and c1 are the consumption characteristic coefficients of the thermal power unit respectively; P t th,th is the output power of the thermal power unit in the t period; and Q coal are the lower calorific values of ammonia and coal respectively; and are the coal consumption and ammonia-doping amount of the thermal power unit in the t period respectively.

[0072] Establish the coupling equation between the ammonia-doping ratio γ t and the output P t th,th of the thermal power unit, and solve the optimal ammonia-doping ratio through nonlinear programming to ensure that under the constraint of γ max = 20%, the reduction rate of fuel cost is maximized;

[0073] In addition, define the ammonia-doping ratio γ t of the thermal power unit in the t period as

[0074]

[0075] Introduce the ammonia-coal calorific value equivalent substitution factor α. When the wind power output exceeds the load demand, the ammonia-doping ratio γ t is preferentially increased to reduce coal consumption, and at the same time, the pumped-storage power station is triggered to enter the pumping mode to store the excess wind power.

[0076] Ammonia-coal calorific value equivalent substitution factor:

[0077]

[0078] During the operation of the thermal power unit, its rotor will incur losses and increase costs. When the unit is in the RPR stage, this part can be ignored; however, when it is in the DPR (Rated Power Regulation Range) stage, the alternating thermal stress of the rotor shafting is too large, causing low-cycle fatigue loss and creep loss of the unit body, and its loss cost is too large to be ignored. In addition, according to the loss degree, the DPR (Deep Peak Regulation Range) is divided into DPR1 and DPR2. Determine the number of cycles L (Pt th,th ), and calculate the loss cost in combination with the purchase cost of the unit:

[0079]

[0080] Where: τ1 and τ2 are the operation loss coefficients in the DPR1 and DPR2 stages respectively; c unit is the unit cost of the unit; is the loss cost of the thermal power unit at time t.

[0081] Then the operation cost of the thermal power unit is:

[0082]

[0083] Where c coal is the unit price of coal;

[0084] After introducing the ammonia-doped combustion retrofit unit, the CO2 emissions of the thermal power unit can be reduced, and the reduction rate is equal to the fuel substitution rate based on calorific value. Then the carbon emission cost is:

[0085]

[0086] Where: e G and e H are the carbon emission quotas per unit of power supply and the carbon emission electricity quotas per unit of heat supply respectively; E is the carbon emission right quota; is the CO2 emission at time t; is the amount of CO2 emitted per unit of coal combustion; c e is the carbon emission quota penalty cost coefficient.

[0087]

[0088] Where: is the coal consumption of the cogeneration unit at time t; a2, b2, c2 and c ν1 are the characteristic coefficients of the cogeneration unit; and are the electric power and heat power output by the cogeneration unit at time t respectively.

[0089] During the operation of the thermal power unit, SO2 and NOx will be emitted into the environment. Although ammonia-doped combustion will bring NOx emission risks, it can be effectively regulated through methods such as staged combustion and combustion organization. Assuming that the NOx emission calculation method after ammonia-doped combustion of the thermal power unit is the same as that under pure coal combustion, the calculation formula for the environmental cost is as follows:

[0090]

[0091] Where: J is the type of taxable pollutant; K is the tax amount payable per pollution equivalent number; m j is the mass of the jth pollutant generated during unit coal combustion; η j is the removal efficiency of the jth pollutant by the environmental protection device; G j is the pollution equivalent number of the jth pollutant.

[0092] In this embodiment, the constraint conditions of the combined power generation system optimization dispatching operation model of ammonia injection combustion - pumped - storage are expressed as:

[0093] Output power constraints of wind power, photovoltaic power and coal - fired units:

[0094]

[0095] P t wt,N and P t pv,N are the output powers of wind power and photovoltaic power directly supplied to the electrical load demand at time t, respectively; is the minimum output power of the coal - fired unit.

[0096] WHB collects the waste heat generated by GT and provides the user with heat load. The model of WHB can be expressed as:

[0097] P WHB,t =Q th,t η WHB (18)

[0098] U WHB,t P WHBmin ≤P WHB,t ≤U WHB,t P WHB,max (19)

[0099] Pumped - storage constraints:

[0100]

[0101] Where, are the minimum reservoir capacity, reservoir capacity at time t, and maximum reservoir capacity of the pumped - storage power station, respectively; Q h,in (t), Q h,out (t) are the inflow and outflow flows of the pumped - storage power station at time t, respectively; η c,cx 、η d,cx are the pumping and generating efficiencies of the pumped - storage power station, respectively.

[0102] In a specific embodiment, a linear approximation is made to the pumped - storage power station constraints, and the change in reservoir capacity is expressed as an affine function of P t o / P t e 。

[0103] Pumping and power generation constraints:

[0104]

[0105] Pumped storage ramp constraint

[0106]

[0107] Wind and solar power curtailment constraints.

[0108]

[0109] In the formula: P t wt,ab and P t pv,ab are the wind power curtailment and solar power curtailment respectively; and are the maximum allowable curtailment rates of wind power and photovoltaic power respectively, which are 15% and 10% respectively

[0110] P t th,th +P t th,chp =P t th (24)

[0111]

[0112] In the formula is the required power of the thermal load in period t.

[0113] Electrical load balance constraint. The electrical load balance constraint needs to be satisfied in each scheduling period:

[0114] P t wt,N +P t pv,N +P t th =P WHB,t =Q GT,t η WHB (26)

[0115] In the formula, P t load is the electrical load demand power in period t.

[0116] Since the internal combustion conditions will be affected to a certain extent when ammonia is added to the thermal power unit, it is necessary to restrict the ammonia addition ratio:

[0117] 0 ≤ γ t ≤ γ max In formula (27): γ maxis the maximum allowable ammonia blending ratio. The upper limit of the ammonia blending ratio is set at 20%.

[0118] Ramping constraint for coal-fired units:

[0119]

[0120] In the formula and are the maximum allowable ramping powers for power supply and heat supply of thermal power units and combined heat and power units respectively.

[0121] Multi-energy ramping coordination constraint:

[0122] Jointly constrain the ramping rates of thermal power and pumped storage

[0123]

[0124] Operating region constraint:

[0125]

[0126] In the formula: and are the lower and upper limits of the power generation of the extraction condensing combined heat and power unit under the pure condensing condition respectively; is the upper limit of the heat supply power of the combined heat and power unit.

[0127] Step S2, Solve the optimal dispatch operation model with the objective function within the constraint conditions. During the solution process, solve for the optimal ammonia blending ratio under the constraint condition of the ammonia blending ratio γ t to maximize the fuel cost reduction rate.

[0128] The solution of the optimal dispatch operation model is carried out using the improved mixed-integer second-order cone programming (MI-SOCP) algorithm. Among them, the ammonia blending ratio and the output of the thermal power unit are combined into an equivalent coal consumption variable to reduce the dimension of the decision variable, expressed as:

[0129]

[0130] In the formula, represents the equivalent coal consumption variable;

[0131] The solution of the ammonia blending ratio γ t is carried out using a hierarchical solution strategy. The outer loop uses the genetic algorithm to solve the integer combination of the ammonia blending ratio γ t , both the population size and the number of iterations are preset in advance. The inner loop optimizes the continuous variables for the fixed ammonia blending ratio γ t combination, calls the CPLEX solver to calculate the objective function value of the optimal dispatch operation model to determine the optimal ammonia blending ratio γ t .

[0132]

[0133] Among them, c coal represents the unit price of coal.

[0134] In a specific embodiment, the hierarchical solution strategy includes: outer loop: solving the integer combination of the ammonia blending ratio γ t using the genetic algorithm (GA), population size = 50, number of iterations = 100; inner loop: for a fixed ammonia blending ratio γ t combination, calling the CPLEX solver for continuous variable optimization and calculating the objective function value.

[0135] In another specific embodiment, a robustness enhancement mechanism is added, introducing the wind power output fluctuation range:

[0136] P t wt ∈[0.9P t wt,pre , 1.1P t wt,pre , constructing a two-stage robust optimization model to ensure that the system still meets the constraint conditions under the worst wind power scenario;

[0137] Define that ξ > 85% is forced during the optimization process of the wind power accommodation robustness index.

[0138]

[0139] In summary, the working principle of this embodiment is system initialization and parameter setting. First, the initialization of each component of the combined power generation system is completed, including thermal power units, pumped storage power stations, wind power, and photovoltaic systems, and key operating parameters are set, such as unit output limits, pumped storage reservoir capacity, and cogeneration characteristic coefficients. Then, an optimal scheduling model is established. Based on economic and environmental protection objectives, a multi-objective function is constructed that includes the operating costs of wind power and photovoltaic power, the costs of curtailed wind and photovoltaic power, the fuel and loss costs of coal-fired units, carbon emissions, and environmental costs. The physical constraints of system operation are set, covering unit output, pumped storage charge-discharge efficiency, power / heat load balance, ammonia blending ratio limit, and ramp rate, etc., and an efficient optimization algorithm is selected to solve the model. Then, the system is optimized for scheduling. Using real-time data and prediction results, the optimal output scheme of each unit is obtained through model solving, the ammonia blending ratio of thermal power units is dynamically adjusted to reduce carbon emissions, and at the same time, the pumping / generation strategy of pumped storage is optimized to balance power supply and demand. On the premise of ensuring power and heat load requirements, wind power / photovoltaic power is preferentially absorbed, the wind and photovoltaic curtailment rates are reduced, and the coordinated operation of multiple energy sources is achieved. Finally, performance evaluation and iterative optimization are carried out. The scheduling results are evaluated from multiple dimensions, including indicators such as economic cost, carbon emissions, and system reliability. Based on the evaluation data, the model parameters and constraints are optimized, and the scheduling strategy is iteratively improved. The operating data is recorded and the rules are analyzed to provide data support for long-term system upgrades or policy formulation, and ultimately the efficient utilization of sustainable energy is realized.

[0140] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. An optimized dispatching method for an ammonia-doped combustion, pumped storage and wind power combined power generation system, characterized in that, Including: Construct an optimal dispatching operation model for ammonia-doped combustion, pumped-storage energy, and wind power combined power generation; The objective function of the optimized scheduling operation model includes a combustion stability penalty term related to the ammonia blending ratio γ of thermal power units t ; The constraint conditions of the optimized scheduling operation model include the constraint conditions of the ammonia blending ratio γ t ; Solve the optimization scheduling operation model through the objective function within the constraint conditions. During the solution process, solve for the optimal ammonia blending ratio under the constraint condition of ammonia blending ratio γ t to maximize the reduction rate of fuel cost.

2. The optimization scheduling method according to claim 1, wherein The calculation formulas for the combustion stability penalty term and the ammonia doping ratio are: 0 ≤ γ t ≤ γ max Among them, C stab represents the combustion stability penalty term, γ t represents the ammonia blending ratio, γ safe is the safety valve threshold, k is the penalty coefficient, Q NH3 and Q coal are the lower calorific values of ammonia and coal respectively; a1, b1 and c1 are the consumption characteristic coefficients of the thermal power unit; P t th,th is the output power of the thermal power unit at time t; and are the coal consumption and ammonia blending amount of the thermal power unit at time t respectively, γ max is the maximum allowable ammonia blending ratio, and α is the ammonia - coal calorific value equivalent substitution factor.

3. The optimization scheduling method according to claim 2, wherein The method further includes: When the ammonia doping ratio is greater than the safety threshold, increase the minimum output of the thermal power unit to a preset ratio of the rated value; When the ammonia doping ratio is equal to the maximum allowable ammonia doping ratio, compensation is carried out through a correction coefficient, and the formula is expressed as: where k η represents a correction coefficient.

4. The optimization scheduling method according to claim 1, characterized in that The constraint conditions of the optimal dispatching operation model further include multi-energy ramp coordination constraints, and the multi-energy ramp coordination constraints are expressed as: where P t th,th is the output power of the thermal power unit in period t, and Pte represents the power generation of the pumped-storage energy in period t.

5. The optimization scheduling method according to claim 2, wherein The objective function of the optimal dispatching operation model is expressed as: Among them, C represents the total cost; C wt represents the operating cost of wind power; C pv represents the operating cost of photovoltaic power; C ab represents the cost of curtailed wind and solar power; C th represents the operating cost of coal-fired units; represents the carbon emission cost; C ep represents the environmental cost; P t wt 、P t pv 、P t ab 、P t th 、 P t ep respectively represent the power output by the corresponding system at time t; Δt represents the time interval; and are respectively the operating costs of thermal power units and combined heat and power units.

6. The optimization scheduling method according to claim 5, wherein The operating cost of the combined heat and power unit The calculation formula is as follows: In the formula: is the coal consumption of the cogeneration unit in period t; a2, b2, c2 and c ν1 are the characteristic coefficients of the cogeneration unit; P t th,chp2 and are respectively the electric power and heat power output by the cogeneration unit in period t; Operating costs of thermal power units The calculation method is as follows: When the thermal power unit is in the RPR stage, the loss cost of the thermal power unit is negligible. When the thermal power unit is in the DPR stage, the calculation formula for the operating cost of the thermal power unit is: where τ1 and τ2 are the operating loss coefficients in the DPR1 and DPR2 stages, respectively; c unit is the unit cost of the unit; is the loss cost of the thermal power unit at time t, c coal is the unit price of coal.

7. The optimized scheduling method according to claim 6, wherein The carbon emission cost is calculated by the following formula: where: e G and e H are the carbon emission quotas of the power supply unit and the heat supply unit's carbon emission electricity quotas respectively; E is the carbon emission right quota; is the CO2 emission volume in period t; is the CO2 emission volume per unit of coal combustion; c e is the carbon emission quota penalty cost coefficient; Environmental cost C ep The calculation formula is as follows: Where: J is the type of taxable pollutant; K is the tax amount payable per pollution equivalent number; m j is the mass of the j-th pollutant generated during unit coal combustion; η j is the removal efficiency of the j-th pollutant by the environmental protection device; G j is the pollution equivalent number of the j-th pollutant.

8. The optimization scheduling method according to claim 2, wherein The optimal dispatching operation model is solved using an improved mixed-integer second-order cone programming (MI-SOCP) algorithm. Among them, the ammonia doping ratio and the output of the thermal power unit are combined into an equivalent coal consumption variable to reduce the dimension of the decision variables, which is expressed as: Indicates the equivalent coal consumption variable.

9. The optimization scheduling method according to claim 8, wherein The calculation formula for the fuel cost reduction rate is: Among them, c coal represents the unit price of coal.

10. The optimization scheduling method according to claim 9, wherein The ammonia blending ratio γ t is solved by using a hierarchical solution strategy. The outer loop uses a genetic algorithm to solve the integer combination of the ammonia blending ratio γ t . The population size and the number of iterations are both preset in advance. The inner loop performs continuous variable optimization by calling the CPLEX solver for a fixed ammonia blending ratio γ t combination, calculates the objective function value of the optimized scheduling operation model, and determines the optimal ammonia blending ratio γ t .

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