An environmental-economic dispatch method considering the impact of carbon emission quotas and regional pollutant concentration constraints

Abstract

The present invention relates to an environmental economic dispatch method considering the influence of carbon emission quotas and regional pollutant concentration constraints. The A-value method is used to calculate the regional atmospheric environmental capacity coefficient to determine the concentration thresholds of environmental pollutants in each region. Based on the traditional benchmark value method and considering the pollutant concentration thresholds, the initial carbon emission quotas for each region are determined, thereby establishing a carbon trading cost model. The multi-source Gaussian plume diffusion model is used to establish a pollutant concentration distribution model for coal-fired power units from three dimensions of time, space, and concentration. An environmental economic dispatch optimization model is established considering pollutant concentration constraints and carbon trading costs. Compared with the prior art, the present invention allocates the initial carbon emissions quotas considering regional environmental differences, establishes an optimization model starting from controlling carbon emissions and restricting the spatio-temporal distribution of pollutant concentrations, reasonably adjusts the unit output, and alleviates the environmental pressure in regions with lower pollutant concentration thresholds.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-carbon optimization of power systems, and particularly relates to an environmental and economic dispatch method considering the influence of carbon emission quotas and regional pollutant concentration constraints. Background Art

[0002] As a tool for using market means to limit greenhouse gas emissions, carbon emissions trading has been adopted by more and more countries and regions. The low-carbon transformation of the power system is the key for the power industry to respond to climate change and implement deep emission reduction, which not only requires the support of various low-carbon technologies, but also needs to build a suitable market mechanism to provide incentives for market players to reduce carbon emissions.

[0003] The reasonable allocation of carbon emission rights is the basis for building a carbon trading market. At present, the unified carbon emission quota and the carbon emission control for the total amount do not consider the impact of regional environmental differences on carbon trading costs and emission reduction strategies, and it is difficult to balance the control of the total carbon emissions and the distribution of pollutants. Summary of the Invention

[0004] Aiming at the above problems existing in the existing low-carbon dispatch methods for regional power systems, the present invention aims to propose an environmental and economic dispatch method to achieve double constraints on the total amount of carbon emissions and the distribution of regional pollutant concentrations.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An environmental and economic dispatch method considering the influence of carbon emission quotas and regional pollutant concentration constraints, comprising the following steps:

[0007] Step 1: Calculate the regional atmospheric environmental capacity coefficient by the A-value method to determine the concentration threshold of environmental pollutants in each region;

[0008] Step 2: Based on the reference value method, determine the initial carbon emission quota for each region considering the pollutant concentration threshold, and establish a stepped carbon trading cost model;

[0009] Step 3: Establish a pollutant concentration distribution model for coal-fired power units from three dimensions of time, space, and concentration by using the multi-source Gaussian plume diffusion model;

[0010] Step 4: Take carbon trading costs, unit start-stop costs, wind and light abandonment costs, etc. as objectives, and establish an environmental and economic dispatch model considering regional environmental pollutant concentration constraints;

[0011] Step 5: Conduct refined operation simulation with an annual operation cycle, solve the model to obtain the optimal power output of the power source, the operation curves of each device, and the power distribution of coal-fired power units.

[0012] Further, in the said step 1, when solving the atmospheric environmental capacity according to the A-value method, the pollutant concentration at the regional boundary is expressed as:

[0013]

[0014]

[0015] where: A is the atmospheric environmental capacity coefficient, km 2 / a; H is the mixing layer height, m; v d , v w are the average dry deposition velocity and wet deposition velocity respectively, m / s; U is the gas advection velocity, m / s; S is the area of this region, km 2 ; c is the pollutant concentration, mg / m 3 , when A = 0, c = c0; q is the emission amount of the atmospheric pollutant at the concentration of c, t / a; t represents time.

[0016] The obtained pollutant concentration threshold of region k is:

[0017]

[0018] where, tv k is the pollutant concentration threshold of region k, that is, the maximum pollutant concentration that this region can bear, mg / m 3 ; q k is the total pollutant emission amount of region k, t; A k is the atmospheric environmental capacity coefficient of region k, km 2 / a; v k is the wind speed of region k, m / s; S k is the area of region k, km 2 ; H k is the mixing layer height of region k, m.

[0019] Further, in the said step 2, when determining the initial carbon emission quota of each region considering the pollutant concentration threshold, first, the initial carbon emission quota determined by the benchmark value method is:

[0020]

[0021] In the formula, cea k.0 represents the initial carbon emission quota of region k, quota0 is the initial carbon emission quota coefficient per unit power generation, P t.k represents the power generation of region k at time t, and T is the scheduling period.

[0022] Secondly, based on the initial carbon emission quota, the carbon emission quota is adjusted according to the regional environmental pollutant threshold. The planning area is divided into K sub-regions according to environmental differences, and the pollutant concentration threshold of sub-region k0 is tv k0 , assuming that the carbon quota coefficient per unit power generation in this region is quota0. If the regional environmental concentration threshold satisfies tv k ≤tv k+1 , then the carbon quota coefficient of region k is:

[0023]

[0024] where K is the total number of divided regions, and quota k is the carbon quota coefficient of region k considering the atmospheric environment background. ω represents the correlation coefficient between the pollutant concentration threshold and the carbon emission quota. Since there is an order-of-magnitude difference between the pollutants and carbon dioxide emissions of thermal power units, a conversion is required between the two.

[0025] Furthermore, in step 2, the stepped carbon trading cost model is:

[0026]

[0027]

[0028] In the formula, f CO2 represents the carbon trading cost function, cem k is the carbon emission of region k, Δcem k is the carbon emission trading volume of region k, cc represents the carbon emission coefficient of coal-fired units, cea k represents the carbon emission quota of region k, P C.t.k is the power of the thermal power unit in region k at time t, P t.k represents the total power of the power supply in region k at time t, θ is the length of the carbon emission interval, λ are the growth rates of the carbon trading price intervals respectively, and C1 is the basic carbon trading price.

[0029] Furthermore, in step 3, the pollutant concentration distribution model of coal-fired units is derived from the following process:

[0030] The ground concentration of an elevated continuous point source is:

[0031]

[0032] where c is the pollutant concentration; x, y, and z respectively represent the coordinate values of any point to the origin; σ y , σ z are the horizontal diffusion coefficient and vertical diffusion coefficient respectively; v is the average wind speed, m / s; the effective height of the chimney is H cIs the actual height H of the chimney cs And the plume rise height ΔH c The sum, where Q is the mass of pollutants emitted by the coal-fired power plant per unit time.

[0033] Unify the wind direction coordinate system into the geographic coordinate system:

[0034]

[0035] Among them, x and y are the coordinate variables used in the Gaussian plume diffusion model, in m; x pol 、y pol Are the coordinate variables of the point source in the geographic coordinate system, in m; x mon 、y mon Are the coordinate variables of the calculation point or monitoring point in the geographic coordinate system, in m; Is the wind direction angle (with the due south direction as the positive direction), in degrees;

[0036] Based on this, the concentration value of the emissions m of the coal-fired unit i at the coordinates (x, y, 0) can be obtained:

[0037]

[0038] Among them, Is the concentration value of the pollution m of unit i, Represents the emission of pollutant m from unit i.

[0039] Therefore, the concentration contribution value of the pollutants m of the coal-fired units in area k at time t can be expressed by the formula as:

[0040]

[0041] Among them, Represents the concentration contribution of the pollutants m of the coal-fired unit in area k at time t, Is the concentration of pollutant m of unit i at the detection point j at time t, Y is the number of pollutant concentration detection points, and N is the number of coal-fired units.

[0042] Furthermore, in the step 4, the objective function of the environmental economic dispatch model includes carbon trading cost, operation and maintenance cost, wind and light abandonment cost, fuel cost and unit start-stop cost:

[0043] min F = F cem +F om +F ab +F fuel +F sts (13)

[0044]

[0045] In the formula, F cem 、Fom , F ab , F fuel , F sts are the carbon trading cost, operation and maintenance cost, curtailment cost of wind and solar power, fuel cost, and unit start-stop cost respectively. P g.t represents the power of power source g at time t. Δcem k.t is the carbon emission trading volume in region k at time t. P r.t , are the actual output value and predicted value of wind power and photovoltaic power respectively. a i , b i , c i are the coal consumption coefficients of coal-fired unit i, PG i.t is the power of thermal power unit i at time t. ε f , ε ab are the fuel cost coefficient and curtailment cost coefficient of wind and solar power respectively. ud represents the start-stop cost coefficient, and SS i.t is the operating state of coal-fired unit i at time t, 1 for operating and 0 for shutdown.

[0046] Furthermore, in step 4, the constraint conditions of the environmental economic dispatch model include the characteristics constraints of the carbon capture unit (Carbon capture and storage, CCS), methanation unit (Methanation equipment, ME), and hybrid energy storage unit (Hybrid energy storage, HES), that is:

[0047]

[0048] Among them, η CCS represents the power consumption coefficient of CCS, V CO2.CCS.t represents the CO2 capture volume at time t, P CCS.t represents the power consumption of CCS at time t; α CCS is the capture efficiency of CCS, V CO2.t is the carbon emission of the thermal power unit; η PC is the carbon emission coefficient of the thermal power unit, P C.t is the power of the thermal power unit.

[0049]

[0050] Among them, V CH4.t , P CH4.t , η CH4 are the methane production, power consumption, and power consumption coefficient at time t respectively; V H2.CH4.t , α H2.CH4 are the hydrogen consumption and hydrogen consumption coefficient respectively; V CO2.CH4.t , α CO2.CH4They are the carbon consumption and carbon consumption coefficient respectively.

[0051]

[0052]

[0053] In the formula, η EC is the electrolytic hydrogen production efficiency, P EL.t , V HS.EC.t are the power of the electrolytic hydrogen production equipment and the hydrogen production amount at time t respectively; η FC is the fuel cell working efficiency, P FC.t , V HS.FC.t represent the power generation power and hydrogen consumption amount of the fuel cell at time t respectively; P BA.c.t is the charging power of the storage battery; P BA.d.t is the discharging power of the storage battery; η s is the charge-discharge efficiency of energy storage; SOC HS.t is the energy storage state of the hydrogen energy storage at time t, SOC HS.0 is the initial energy storage state of the hydrogen energy storage, CAP HS is the installed capacity of the hydrogen energy storage, H HS.max is the longest storage time of the hydrogen energy storage, δ s.0 represents the proportion of the initial storage amount; SOC BA.t is the energy storage state of the electrical energy storage at time t, SOC BA.0 is the initial energy storage state of the electrical energy storage, CAP BA is the installed capacity of the electrical energy storage, H BA.max is the longest storage time of the electrical energy storage.

[0054] Furthermore, in the step 4, the constraint conditions of the environmental economic dispatch model include the balance of power, hydrogen, and carbon energy flows, that is:

[0055] P C.t +P W.t +P PV.t +P H.t +P FC.t +P BA.d.t =P CCS.t +P EL.t +P CH4.t +P BA.c.t +L E.t (19)

[0056] V HS.EC.t =V HS.FC.t +V H2.CH4.t (20)

[0057] V CO2.t -V CO2.CH4.t =cem t (21)

[0058] Among them, P C.t , P W.t , P PV.t , P H.t are the power outputs of thermal power, wind power, photovoltaic power, and hydropower at time t respectively, and L E.t is the electrical load value at time t. cem t is the carbon emission at time t.

[0059] The power output of each thermal power unit needs to meet the total thermal power dispatch demand, that is:

[0060]

[0061] Furthermore, in the said step 4, the constraint conditions of the environmental economic dispatch model include the regional environmental pollutant concentration constraint:

[0062]

[0063] Among them, represents the background concentration of pollutant m in region k at time t, represents the concentration threshold of pollutant m in region k.

[0064] Finally, a refined operation simulation is carried out with a one-year operation cycle, and the optimal power output of the power source, the operation curves of each device, and the power distribution of the coal-fired units are obtained by solving this model.

[0065] Beneficial effects:

[0066] Adopting a regional differentiated carbon emission quota allocation method can effectively improve the power distribution of coal-fired units, reduce the annual operation cost, and reduce carbon emissions; at the same time, considering the environmental concentration constraint of pollutants can adjust the power output of coal-fired units and relieve the environmental pressure in regions with lower pollutant concentration thresholds. Description of the drawings

[0067] Figure 1 is the energy flow diagram of the high-proportion renewable energy power system in the embodiment cited in the present invention;

[0068] Figure 2 is the schematic diagram of the positions of the coal-fired units in the embodiment cited in the present invention;

[0069] Figure 3 is the electrical load curve in the embodiment cited in the present invention;

[0070] Figure 4 is the power curve of each device unit obtained in the embodiment cited in the present invention;

[0071] Figure 5 is the carbon emission of each region obtained in the embodiment cited in the present invention;

[0072] Figure 6This is the variation of SO2 concentration in each region obtained in the embodiments of the present invention with time. Detailed implementation manners

[0073] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0074] The following further describes the embodiments of the present invention in detail with reference to the drawings. An environmental economic dispatch method considering the influence of carbon emission quotas and regional pollutant concentration constraints includes the following steps:

[0075] Step 1: Calculate the regional atmospheric environmental capacity coefficient by using the A-value method and determine the concentration thresholds of environmental pollutants in each region;

[0076] Step 2: Determine the initial carbon emission quotas of each region based on the benchmark value method and considering the pollutant concentration thresholds, and establish a stepped carbon trading cost model;

[0077] Step 3: Establish a pollutant concentration distribution model for coal-fired power units from three dimensions of time, space and concentration by using a multi-source Gaussian plume diffusion model;

[0078] Step 4: Take carbon trading costs, unit start-stop costs, wind and light abandonment costs, etc. as objectives, and establish an environmental economic dispatch model considering regional environmental pollutant concentration constraints;

[0079] Step 5: Conduct refined operation simulation with an annual operation cycle, solve the model to obtain the optimal power output of the power source, the operation curves of each device, and the power distribution of coal-fired power units.

[0080] According to the A-value method to solve the atmospheric environmental capacity, the expression of the pollutant concentration at the regional boundary is:

[0081]

[0082]

[0083] Where: A is the atmospheric environmental capacity coefficient, km 2 / a; H is the mixing layer height, m; v d 、v w are the average dry deposition velocity and wet deposition velocity respectively, m / s; U is the gas advection velocity, m / s; S is the area of this region, km 2 ; c is the pollutant concentration, mg / m 3, when A = 0, c = c0; q is the emission of air pollutants at concentration c, t / a; t represents time.

[0084] Thus, the pollutant concentration threshold of the area k that can be obtained is:

[0085]

[0086] Among them, tv k is the pollutant concentration threshold of area k, that is, the maximum pollutant concentration that this area can bear, mg / m 3 ; q k is the total pollutant emission of area k, t; A k are the atmospheric environmental capacity coefficients of area k respectively, km 2 / a; v k is the wind speed of area k, m / s; S k is the area of area k, km 2 ; H k is the mixing layer height of area k, m.

[0087] The initial carbon emission quota determined by the benchmark value method is:

[0088]

[0089] In the formula, cea k.0 represents the free carbon emission quota of area k, quota0 is the initial carbon emission quota coefficient per unit of power generation, and P t.k represents the power generation of area k at time t, and T is the scheduling period.

[0090] Adjust the carbon emission quota according to the regional environmental pollutant threshold. The planning area is divided into K sub-areas according to environmental differences. The pollutant concentration threshold of sub-area k0 is tv k0 , assuming that the carbon quota coefficient per unit of power generation in this area is quota0. If the regional environmental concentration threshold satisfies tv k ≤tv k+1 , then the carbon quota coefficient of area k is:

[0091]

[0092] Among them, K is the total number of divided areas, and quota k is the carbon quota coefficient of area k considering the atmospheric environmental background. ω represents the correlation coefficient between the pollutant concentration threshold and the carbon emission quota. Since there is an order-of-magnitude difference between the pollutants and carbon dioxide emissions of thermal power units, conversion is required between the two.

[0093] The stepped carbon trading cost model established based on the above carbon quota is:

[0094]

[0095]

[0096] In the formula, f CO2 represents the carbon trading cost function, and cem k is the carbon emission of region k, and Δcem k is the carbon emission trading volume of region k. Cc represents the carbon emission coefficient of coal-fired units, and cea k represents the carbon emission quota of region k. P C.t.k is the power of the thermal power unit of region k at time t, and P t.k represents the total power of the power supply of region k at time t. θ is the length of the carbon emission interval, and λ are the growth rates of the carbon trading price interval respectively, and C1 is the basic carbon trading price.

[0097] The ground concentration of the elevated continuous point source is:

[0098]

[0099] Among them, c is the pollutant concentration; x, y, and z respectively represent the coordinate values of any point to the origin; σ y and σ z are the horizontal diffusion coefficient and the vertical diffusion coefficient respectively; v is the average wind speed, m / s; the effective height H c of the chimney is the sum of the actual height H cs of the chimney and the plume rise height ΔH c , and Q is the mass of pollutants emitted by the coal-fired power plant per unit time.

[0100] Unify the wind direction coordinate system into the geographic coordinate system:

[0101]

[0102] Among them, x and y are the coordinate variables used in the Gaussian plume diffusion model, m; x pol and y pol are the coordinate variables of the geographic coordinate system of the point source, m; x mon and y mon are the coordinate variables of the geographic coordinate system of the calculation point or the monitoring point, m; is the wind direction angle (with the due south direction as the positive direction), degree;

[0103] Based on this, the concentration value of the emission m of the coal-fired unit i at the coordinate (x, y, 0) can be obtained:

[0104]

[0105] Among them, is the concentration value of the pollution of unit i to m. represents the emission of pollutant m from unit i.

[0106] Therefore, the contribution value of the pollutant m concentration of the coal-fired units in area k at time t can be expressed by the formula:

[0107]

[0108] where represents the contribution of the pollutant m concentration of the coal-fired unit in area k at time t. is the concentration of pollutant m of unit i at the detection point j at time t, Y is the number of pollutant concentration detection points, and N is the number of coal-fired units.

[0109] So far, an environmental and economic dispatch model can be established. The objective function includes carbon trading cost, operation and maintenance cost, wind and light abandonment cost, fuel cost, and unit start-stop cost:

[0110] min F = F cem + F om + F ab + F fuel + F sts (13)

[0111]

[0112] In the formula, F cem 、F om 、F ab 、F fuel 、F sts are the carbon trading cost, operation and maintenance cost, wind and light abandonment cost, fuel cost, and unit start-stop cost respectively. T is the dispatch period. Δcem k.t is the carbon emission trading volume in area k at time t. C inv.g 、ε g are the unit investment cost and operation and maintenance cost coefficient of power source g, and P g.t represents the power of power source g at time t. P r.t 、 are the actual output value and predicted value of wind power and photovoltaic power respectively. a i 、b i 、c i are the coal coefficients of coal-fired unit i, and PG i.t is the power of thermal power unit i at time t. ε f 、ε ab are the fuel cost coefficient and wind and light abandonment cost coefficient respectively, ud represents the start-stop cost coefficient, and SS i.t is the operating state of coal-fired unit i at time t, 1 means operating, and 0 means shutdown.

[0113] The constraints include equipment characteristic constraints, energy flow balance constraints, and pollutant concentration distribution constraints:

[0114] (1) Carbon capture and storage (CCS):

[0115]

[0116] Among them, η CCS represents the power consumption coefficient of CCS, V CO2.CCS.t represents the CO2 capture amount at time t, P CCS.t represents the power consumption of CCS at time t; α CCS is the capture efficiency of CCS, V CO2.t is the carbon emission of the thermal power unit; η PC is the carbon emission coefficient of the thermal power unit, P C.t is the power of the thermal power unit.

[0117] (2) Methanation equipment (ME):

[0118]

[0119] Among them, V CH4.t , P CH4.t , η CH4 are the methane production, power consumption, and power consumption coefficient at time t respectively; V H2.CH4.t , α H2.CH4 are the hydrogen consumption and hydrogen consumption coefficient respectively; V CO2.CH4.t , α CO2.CH4 are the carbon consumption and carbon consumption coefficient respectively.

[0120] (3) Hybrid energy storage (HES):

[0121]

[0122]

[0123] In the formula, η EC is the hydrogen production efficiency by electrolysis, P EL.t , V HS.EC.t are the power of the hydrogen production equipment by electrolysis and the hydrogen production amount at time t respectively; η FC is the working efficiency of the fuel cell, P FC.t , V HS.FC.t represent the power generation power of the fuel cell and the hydrogen consumption amount at time t respectively; P BA.c.t is the charging power of the battery; P BA.d.t is the discharging power of the battery; η s is the charge-discharge efficiency of energy storage; SOCHS.t is the energy storage state of hydrogen energy storage at time t, SOC HS.0 is the initial energy storage state of hydrogen energy storage, CAP HS is the installed capacity of hydrogen energy storage, H HS.max is the longest storage time of hydrogen energy storage, δ s.0 represents the proportion of the initial storage amount; SOC BA.t is the energy storage state of electric energy storage at time t, SOC BA.0 is the initial energy storage state of electric energy storage, CAP BA is the installed capacity of electric energy storage, H BA.max is the longest storage time of electric energy storage.

[0124] (4) Power, hydrogen, and carbon energy flow balance:

[0125] P C.t +P W.t +P PV.t +P H.t +P FC.t +P BA.d.t =P CCS.t +P EL.t +P CH4.t +P BA.c.t +L E.t (19)

[0126] V HS.EC.t =V HS.FC.t +V H2.CH4.t (20)

[0127] V CO2.t -V CO2.CH4.t =cem t (21)

[0128] Among them, P C.t 、P W.t 、P PV.t 、P H.t are the outputs of thermal power, wind power, photovoltaic power, and hydropower at time t respectively, and L E.t is the electric load value at time t. cem t is the carbon emission at time t.

[0129] The output of each thermal power unit needs to meet the total thermal power dispatch demand, that is:

[0130]

[0131] (5) Regional environmental pollutant concentration distribution constraint:

[0132]

[0133] Among them, Denote the background concentration of pollutant m at time t in area k. Denote the concentration threshold of pollutant m in area k.

[0134] See the appendix for the system structure Figure 1 The power supply includes four types: wind, solar, water, and fire. The electric energy storage and hydrogen energy storage constitute a hybrid energy storage system. The methanation device synthesizes CH4 using the CO2 captured by the carbon capture device and the H2 produced by electrolyzing water. Among them, there are four energy material flows: electricity, hydrogen, carbon, and methane, and the arrows indicate the flow directions.

[0135] See the appendix for the unit location Figure 2 The planning area is divided into a central area k1, an urban area k2, and a suburban area k3. The coal-fired unit G1 is located in k1, G2 - G3 are located in k2, and G4 - G5 are located in k3.

[0136] The system parameters are as follows:

[0137] Table 1 System configuration

[0138]

[0139] Table 2 Coal-fired unit parameters

[0140]

[0141]

[0142] Output limit [0, 400] (MW), ramping limit 50 MW.

[0143] This embodiment sets four scenarios as follows:

[0144] Scenario 1: Optimize the dispatch with a unified carbon emission quota.

[0145] Scenario 2: Optimize the dispatch with a unified carbon emission quota considering environmental constraints.

[0146] Scenario 3: Optimize the dispatch with regional differentiated carbon emission quotas.

[0147] Scenario 4: Optimize the dispatch with regional differentiated carbon emission quotas considering environmental constraints.

[0148] Use the YALMIP toolbox in MATLAB to call GUROBI for solution. Figure 3 For the electric load curve of the embodiment, the electric load in spring and summer in this area is slightly lower than that in autumn and winter.

[0149] Figure 4Shows the power curves of each equipment unit obtained under Scenario 1. (a), (b), (c), and (d) are the power curves of wind power, hydropower, photovoltaic power, and thermal power respectively. The wind and light power generation is sufficient, and the water resources are rich in summer. Therefore, thermal power mainly plays a role in autumn and winter, and hardly participates in power supply for a long time in spring and summer; (e) is the power curve of the methanation equipment, which can reflect the amount of methane synthesized from CO2 and H2; (f) and (g) are the charge-discharge power of the electrical energy storage and hydrogen energy storage, and the remaining capacity curve of the hydrogen energy storage. The electrical-hydrogen hybrid energy storage system plays an important supporting role; with the assistance of carbon capture, electrolytic hydrogen production, and methanation equipment, the amount of abandoned wind and electricity is 0.

[0150] The carbon emissions of each region are as Figure 5 , under Scenarios 3 and 4, the total carbon emissions in regions k1 and k2 are much less than those in Scenarios 2 and 3. This part of the carbon emissions is transferred to k3 in Scenarios 3 and 4. This is because Scenarios 3 and 4 adopt regionally differentiated initial carbon emission quotas. The environmental coefficients and initial carbon emission quotas in regions k1 and k2 are relatively low, and the carbon trading costs brought by the same amount of carbon emissions are relatively high. Therefore, in power distribution, it is more inclined to give priority to using the units in region k3 for power supply. In terms of the total annual emissions, Scenarios 3 and 4 reduce carbon emissions by more than 1.5×10 4 t compared with Scenarios 1 and 2. This result shows that the regionally differentiated initial carbon emission quota has an obvious control effect on the total carbon emissions.

[0151] The variation of SO2 concentration in each region with time is as Figure 6 , (a)-(d) are the SO2 concentration distributions under Scenarios 1-4 respectively. Under Scenario 1, the SO2 concentrations in regions k1 and K2 both exceed the environmental concentration threshold, with the maximum exceeding the concentration threshold by 1.6%; after considering the regional SO2 concentration distribution in Scenario 2 and imposing constraints, the SO2 concentration distributions in each region return within the regional threshold; although the total carbon emissions are controlled in Scenario 3, there are still some moments when the SO2 concentration in region k2 exceeds the environmental concentration threshold, with the highest exceeding the threshold by 1.99%; Scenario 4 takes into account both the control of the total regional carbon emissions and the constraints on the ground concentration of SO2 at each time period, which not only meets the concentration threshold requirements but also limits the carbon emissions of each region according to environmental differences.

[0152] Considering regionally differentiated carbon quotas can effectively reduce carbon trading costs. Although the unit start-stop cost increases, the overall dispatching cost is much lower than the scheme with unified carbon quotas, and the annual operating cost is reduced by more than 2×10 7 yuan. Considering the atmospheric environment constraints makes the total dispatching cost increase slightly, but the annual operating cost increases by no more than 0.008‰ and 0.002‰. At the same time, it avoids the SO2 concentration exceeding the regional environmental concentration threshold. In the context of giving priority to environmental protection, the scheme of adopting regionally differentiated initial carbon emission quotas and considering atmospheric environment constraints will be more advantageous.

[0153] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An environmental economic dispatch method considering the influence of carbon emission quotas and regional pollutant concentration constraints, characterized in that It includes the following steps: Step 1: Calculate the regional atmospheric environmental capacity coefficient using the A-value method and determine the concentration thresholds of environmental pollutants in each region; Step 2: Based on the benchmark value method and considering the pollutant concentration thresholds, determine the initial carbon emission quotas for each region and establish a stepped carbon trading cost model; Step 3: Use the multi-source Gaussian plume diffusion model to establish a pollutant concentration distribution model for coal-fired units from three dimensions of time, space, and concentration; Step 4: Taking the carbon trading cost, unit start-stop cost, and wind and photovoltaic abandonment costs as objectives, establish an environmental and economic dispatch model considering the regional environmental pollutant concentration constraints; Step 5: Conduct operation simulation with an annual operation cycle, solve the model to obtain the optimal power output of the power source, the operation curves of each device, and the power distribution of coal-fired units; In the said Step 1, when solving the atmospheric environmental capacity using the A-value method, the pollutant concentration at the regional boundary is expressed as: (1) (2) Where: A is the atmospheric environmental capacity coefficient, km 2 / a; H is the mixing layer height, m; v d , v w are the average dry deposition velocity and wet deposition velocity, m / s respectively; U is the gas advection velocity, m / s; S is the area of this region, km 2 ; c is the pollutant concentration, mg / m 3 , when A = 0, c = c0; q is the emission amount of atmospheric pollutants at the concentration of c, t / a; t represents time; The obtained pollutant concentration threshold for region k is: (3) Among them, tv k is the pollutant concentration threshold of region k, that is, the maximum pollutant concentration that the region can withstand, mg / m 3 ; q k is the total pollutant emission of region k, t; A k is the atmospheric environmental capacity coefficient of region k, km 2 / a; v k is the wind speed of region k, m / s; S k is the area of region k, km 2 ; H k is the mixing layer height of region k, m; In the said Step 2, when considering the pollutant concentration thresholds to determine the initial carbon emission quotas for each region, first, the initial carbon emission quota determined using the benchmark value method is: (4) where cea k.0 represents the initial carbon emission quota of region k, quota0 is the initial carbon emission quota coefficient per unit of power generation, and P t.k represents the power generation of region k at time t, and T is the scheduling period; Secondly, on the basis of the initial carbon emission quota, the carbon emission quota is adjusted according to the regional environmental pollutant threshold; the planning area is divided into K sub-areas according to environmental differences, and the pollutant concentration threshold of sub-area k0 is tv k0 , assuming that the carbon quota coefficient per unit of power generation in this area is quota0, if the regional environmental concentration threshold meets tv k ≤tv k+1 , then the carbon quota coefficient of area k is: (5) where K is the total number of divided regions, and quota k is the carbon quota coefficient considering the atmospheric environmental background for region k; represents the correlation coefficient between the pollutant concentration threshold and the carbon emission quota. Since there is an order-of-magnitude difference in pollutants and carbon dioxide emissions of thermal power units, a conversion is required between the two.

2. The method according to claim 1, wherein In the said Step 2, the stepped carbon trading cost model is: (6) (7) In the formula, represents the carbon trading cost function, is the carbon emission of region k, is the carbon emission trading volume of region k, cc represents the carbon emission coefficient of coal-fired units, represents the carbon emission quota of region k, is the power of the thermal power unit in region k at time t, represents the total power of the power supply in region k at time t, is the length of the carbon emission interval, 、 is the growth rate of the carbon trading price interval, is the basic carbon trading price.

3. The method according to claim 2, wherein In the said Step 3, the pollutant concentration distribution model for coal-fired units is derived from the following process: The ground concentration of the elevated continuous point source is: (9) where c is the pollutant concentration; x, y, and z respectively represent the coordinate values of any point to the origin; σ y , σ z are the horizontal diffusion coefficient and the vertical diffusion coefficient respectively; v is the average wind speed, m / s; the effective height H c of the chimney is the sum of the actual height H cs of the chimney and the plume rise height ΔH c ; Q is the mass of pollutants emitted by the coal-fired power plant during the detection period. Unify the wind direction coordinate system into the geographic coordinate system: (10) Among them, x and y are the coordinate variables used in the Gaussian plume dispersion model, m; x pol , y pol are the coordinate variables of the geographical coordinate system of the point source, m; x mon , y mon are the coordinate variables of the geographical coordinate system of the calculation point or monitoring point, m; is the wind direction angle, with the due south direction as the positive direction, degree; Accordingly, the concentration value of the emission m of coal-fired unit i at the coordinate (x, y, 0) can be obtained: (11) Among them, is the concentration value of the pollution of unit i to m, represents the emission of pollutant m of unit i; Therefore, the concentration contribution value of pollutant m of coal-fired units in region k at time t can be expressed by the formula: (12) Among them, represents the contribution of pollutant m concentration of the coal-fired unit in area k at time t, is the pollutant m concentration of unit i at the detection point j at time t, Y is the number of pollutant concentration detection points, and N is the number of coal-fired units.

4. The method according to claim 3, wherein In the said Step 4, the objective function of the environmental and economic dispatch model includes carbon trading cost, operation and maintenance cost, wind and photovoltaic abandonment costs, fuel cost, and unit start-stop cost: (13) (14) In the formula, , , , , are the carbon trading cost, operation and maintenance cost, curtailment cost of wind and solar power, fuel cost, and unit start-stop cost of the unit respectively; Δcem k.t is the carbon emission trading volume in region k at time t; T is the scheduling period; , are the unit investment cost and operation and maintenance cost coefficient of power source g respectively, and P g.t represents the power of power source g at time t; , are the actual output value and predicted value of wind power and photovoltaic power respectively; , , are the coal consumption coefficients of coal-fired unit i respectively, is the power of thermal power unit i at time t; , are the fuel cost coefficient and curtailment cost coefficient of wind and solar power respectively, ud represents the start-stop cost coefficient, and SS i.t is the operating state of coal-fired unit i at time t, 1 means operating, and 0 means shutdown.

5. The method according to claim 4, characterized in that, In the said Step 4, the constraint conditions of the environmental and economic dispatch model include equipment characteristic constraints, that is: (1) Carbon capture and storage, CCS: (15) Among them, represents the power consumption coefficient of CCS, represents the CO2 capture amount at time t, represents the power consumption of CCS at time t; is the capture efficiency of CCS, is the carbon emission of the thermal power unit; is the carbon emission coefficient of the thermal power unit, is the power of the thermal power unit; (2) Methanation equipment, ME: (16) Among them, , , are the methane production, power consumption, and power consumption coefficient at time t, respectively; , are the hydrogen consumption and hydrogen consumption coefficient, respectively; , are the carbon consumption and carbon consumption coefficient, respectively; (3) Hybrid energy storage, HES: (17) (18) Wherein, is the efficiency of electrolytic hydrogen production, , are respectively the power of the electrolytic hydrogen production equipment and the hydrogen production amount at time t; is the working efficiency of the fuel cell, , respectively represent the power generation power and hydrogen consumption amount of the fuel cell at time t; P BA.c.t is the charging power of the battery; P BA.d.t is the discharging power of the battery; is the charge-discharge efficiency of energy storage; is the energy storage state of hydrogen energy storage at time t, is the initial energy storage state of hydrogen energy storage, is the installed capacity of hydrogen energy storage, is the longest storage time of hydrogen energy storage, represents the proportion of the initial storage amount; is the energy storage state of electrical energy storage at time t, is the initial energy storage state of electrical energy storage, is the installed capacity of electrical energy storage, is the longest storage time of electrical energy storage.

6. The method according to claim 5, wherein In the said Step 4, the constraint conditions of the environmental and economic dispatch model include the balance of power, hydrogen, and carbon energy flows, that is: (19) (20) (21) Among them, , , , are the thermal power, wind power, photovoltaic power, and hydropower outputs at time t respectively, is the electricity load value at time t; is the carbon emission at time t. The power output of each thermal power unit needs to meet the total thermal power dispatch demand, that is: (22)。 7. The method according to claim 6, characterized in that In the said Step 4, the constraint conditions of the environmental and economic dispatch model include regional environmental pollutant concentration constraints: (23) Among them, represents the background concentration of pollutant m at time t in area k, represents the concentration threshold of pollutant m in area k.

8. The method according to claim 7, characterized in that In the said Step 5, conduct refined operation simulation with an annual operation cycle, solve the model to obtain the optimal power output of the power source, the operation curves of each device, and the power distribution of coal-fired units.

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