CN109995084B - A cascade hydropower station-thermal power plant joint optimal scheduling method and system - Google Patents

Abstract

The invention discloses a method and system for joint optimal dispatching of cascade hydropower stations and thermal power plants. The method includes constructing the output model of the thermal power unit of the thermal power plant in the combined hydro-thermal power system; constructing the optimal dispatching model of the combined hydropower-thermal power system according to the output model of the thermal power unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station and the output of the wind power generating unit; using Benders The decomposition algorithm solves the optimal scheduling model of the combined hydropower-thermal power system, and obtains the optimal solution corresponding to the optimal scheduling model of the combined hydropower-thermal power system; the optimal solution includes the optimal output of the thermal power unit and the optimal output of the hydropower unit; The total energy consumption corresponding to the optimal output of the hydroelectric unit and the optimal output of the hydroelectric unit is determined as the optimal total energy consumption of the combined hydro-thermal power system. The invention can improve the power generation capacity of clean energy, achieve the purpose of saving the consumption of traditional fossil energy and reducing the emission of air pollutants.

Description

A cascade hydropower station-thermal power plant joint optimal scheduling method and system

technical field

The invention relates to the technical field of energy optimal dispatching, in particular to a cascade hydropower station-thermal power plant joint optimal dispatching method and system.

Background technique

In recent years, the environmental problems caused by a large number of fossil fuels have become increasingly prominent. People have begun to pay attention to the development and use of clean energy. New energy technologies have been continuously developed and are gradually becoming mature. The vigorous development and utilization of hydropower, wind power, solar energy and other clean energy sources for power generation has received extensive attention.

As the most important clean energy in my country, hydropower has gradually changed from the development mode of independent hydropower stations to a new mode of cascade hydropower stations in the basin in recent years. At the same time, among various renewable energy power generation technologies, wind power generation is the most mature and cost-effective power generation technology. However, due to the inherent intermittent and randomness of wind power, its large-scale grid connection will have a greater impact on the system.

To sum up, there is an urgent need for a joint system scheduling method that can improve the power generation capacity of clean energy and save the consumption of traditional fossil energy.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a cascade hydropower station-thermal power plant joint optimal scheduling method and system to improve the power generation capacity of clean energy, save the consumption of traditional fossil energy, and reduce the emission of air pollutants.

For achieving the above object, the present invention provides the following scheme:

A cascade hydropower station-thermal power plant joint optimal scheduling method, comprising:

Build the output model of the thermal power unit of the thermal power plant in the combined water and thermal power system;

According to the output model of the thermal power generation unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station and the output of the wind power generation unit, an optimal dispatch model of the hydropower-thermal power combined system is constructed;

A decomposition optimization algorithm is used to solve the optimal scheduling model of the hydropower-thermal power combined system, and the optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system is obtained; the optimal solution includes the optimal output of the thermal power unit and the hydropower unit. the optimal output;

The optimal total energy consumption of the combined hydro-thermal power system is determined from the total energy consumption corresponding to the optimal output of the thermal power unit and the optimal output of the hydroelectric unit.

Optionally, the output model of the thermal power unit of the thermal power plant is specifically:

Among them, N _T represents the number of thermal power units, P _n,t represents the output of the nth thermal power unit at time t, P _Lt represents the total load of the power grid when there are only thermal power units, and ΔP _t is the total loss of the power grid when there are only thermal power units.

Optionally, according to the output model of the thermal power unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station, and the output of the wind power generating unit, the optimal scheduling model of the hydropower-thermal power combined system is constructed, specifically including:

Objective Function of Establishing Optimal Scheduling Model for Combined Hydropower and Thermal Power System

minF _a =F _H +F _T +F _W

in,

Among them, F _a represents the total energy consumption of the combined hydro-thermal power system, F _H represents the energy consumption of the hydropower unit, F _T represents the energy consumption of the thermal power unit, F _W represents the energy consumption of the wind turbine unit, and T is the dispatch time. , N _H is the number of hydropower units, N _W is the number of fans, q _k,t is the output of the kth hydropower unit at time t, P _n,t is the output of the nth thermal power unit at time t, _{pw , t} is the output of the wth wind turbine at time t, h ^t is the number of hours in the t period, a, b, and c are the quadratic coefficient, primary coefficient and constant term of the water consumption function of the thermal power unit, and μ is the hydraulic power The coal consumption rate per unit time of the power plant, λ is the energy consumption coefficient of wind power generation;

Constraints of the optimal scheduling model of the hydropower-thermal power combined system are established; the constraints of the hydropower-thermal power combined system optimal scheduling model include power balance constraints, hydropower unit constraints, and thermal power unit constraints; the hydropower unit constraints include hydropower Unit output constraints, hydropower unit output limitation constraints, and water balance constraints; the thermal power unit constraints include thermal power unit output limitation constraints, conventional unit ramping constraints, and power grid branch power flow constraints;

The power balance constraints are

Among them, P _Dt is the total load of the combined hydropower station and thermal power plant system;

The output constraints of the hydroelectric unit are:

Among them, V _k,t is the water storage capacity of the kth hydropower unit at time t, Q _k,t is the water output of the hydropower unit, c _1k , c _2k are the secondary water storage capacity and water output in the output constraint of the hydropower unit, respectively term coefficient, c _3k is the first-order coefficient of the product of water storage and water output, c _4k , c _5k are the first-order coefficients of water storage and water output in the output constraint of the hydropower unit, and c _6k is the constant parameter;

The output limit constraints of the hydroelectric unit are:

为第k台水电机组的最小出力，

为第k台水电机组的最大出力；in,

is the minimum output of the kth hydroelectric unit,

is the maximum output of the kth hydroelectric unit;

The water balance constraints are:

表示由于时间延迟存留的水量；R_uk表示第k台水电机组的上游机组的总个数；τ_mk表示上游机组中的第m台水电机组到第k台水电机组的水输送的时间延迟；

表示上游机组中的第m台水电机组由于时间延迟产生的出水量；

表示上游机组中的第m台水电机组由于时间延迟产生的溢水量；Δt表示t-1时刻与t时刻的时间间隔；Among them, V _k,t-1 is the water storage capacity of the kth hydropower unit at time t-1, I _k,t is the water inflow of the kth hydropower unit at time t, and _Qk,t is the kth hydropower unit The water output at time t, S _k,t is the overflow volume of the kth hydropower unit at time t,

Represents the amount of water remaining due to time delay; R _uk represents the total number of upstream units of the k-th hydroelectric unit; τ _mk represents the time delay of water delivery from the m-th hydro-electric unit to the k-th hydro-electric unit in the upstream units;

Represents the water output of the m-th hydropower unit in the upstream unit due to time delay;

Represents the overflow amount of the mth hydropower unit in the upstream unit due to time delay; Δt represents the time interval between time t-1 and time t;

The output limit constraints of the thermal power unit are:

表示第n台火电机组的最小出力，

表示第n台火电机组的最小出力、最大出力；in,

represents the minimum output of the nth thermal power unit,

Indicates the minimum output and maximum output of the nth thermal power unit;

The conventional unit climbing limit constraints are:

p _down,n ≤p _n,t ≤p _up,n ,

Among them, p _down,n represents the maximum down-regulated active power of the nth thermal power unit, and p _up,n represents the maximum up-regulated active power of the nth thermal power unit;

The power flow constraint condition of the power grid branch is:

表示电网中第m条线路的最小潮流，

表示电网中第m条线路的最大潮流，

表示电网中第m条线路在t时刻的潮流。in,

represents the minimum power flow of the mth line in the grid,

represents the maximum power flow of the mth line in the grid,

Represents the power flow of the mth line in the power grid at time t.

Optionally, the Benders decomposition algorithm is used to solve the optimal scheduling model of the combined hydropower-thermal power system, and an optimal solution corresponding to the optimal scheduling model of the combined hydropower-thermal power system is obtained, specifically including:

Step 31: respectively establishing a lower-layer hydroelectric generating unit model and an upper-layer thermal generating unit model according to the optimal scheduling model of the hydropower-thermal power combined system;

Step 32: Solve the lower hydroelectric generating unit model to obtain the upper boundary value of the output q ^v of the hydroelectric generating unit and the energy consumption of the hydroelectric generating unit at the vth iteration

Step 33: Obtain the output p ^v-1 of the thermal power unit and the lower boundary value of the energy consumption of the thermal power unit in the v-1 iteration

和第v-1次迭代的火电机组的能耗量的下边界值

是否满足预设收敛条件；若是，则将第v次迭代的水电机组的出力q^v作为水电机组的最优出力，将第v-1次迭代的火电机组的出力p^v-1作为火电机组的最优出力，若否，则执行步骤35；所述预设收敛条件为

Step 34: Determine the upper boundary value of the energy consumption of the hydroelectric unit in the vth iteration

and the lower bound value of the energy consumption of the thermal power unit at the v-1th iteration

Whether the preset convergence conditions are met; if so, take the output q ^v of the hydroelectric unit at the vth iteration as the optimal output of the hydroelectric unit, and take the output p ^v-1 of the thermal power unit at the v-1 iteration as the output of the thermal power unit Optimal output, if not, go to step 35; the preset convergence condition is

并令v＝v+1，再返回所述步骤32。Step 35: Solve the upper-layer thermal power generation unit model, and obtain the lower boundary value of the output p ^v of the thermal power unit and the energy consumption of the thermal power unit of the v-th iteration

And let v=v+1, and return to step 32.

The present invention also provides a cascade hydropower station-thermal power plant joint optimal dispatching system, comprising:

The first model building module is used to build the output model of the thermal power unit of the thermal power plant in the combined water and thermal power system;

The second model building module is used for constructing a hydropower-thermal power combined system optimal dispatch model according to the output model of the thermal power unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station, and the output of the wind power generating unit;

The solving module is used to solve the optimal scheduling model of the hydropower-thermal power combined system by using the Benders decomposition algorithm, and obtain the optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system; the optimal solution includes the optimal solution of the thermal power unit. optimal output and optimal output of hydroelectric units;

The energy consumption determination module is configured to determine the optimal total energy consumption of the combined hydrothermal power system based on the total energy consumption corresponding to the optimal output of the thermal power unit and the optimal output of the hydroelectric unit.

Optionally, the first model building module is specifically:

Among them, N _T represents the number of thermal power units, P _n,t represents the output of the nth thermal power unit at time t, P _Lt represents the total load of the power grid when there are only thermal power units, and ΔP _t is the total loss of the power grid when there are only thermal power units.

Optionally, the second model building module specifically includes:

The objective function establishment unit is used to establish the objective function of the optimal dispatch model of the hydropower-thermal power combined system

minF _a =F _H +F _T +F _W

in,

Among them, F _a represents the total energy consumption of the combined hydro-thermal power system, F _H represents the energy consumption of the hydropower unit, F _T represents the energy consumption of the thermal power unit, F _W represents the energy consumption of the wind turbine unit, and T is the dispatch time. , N _H is the number of hydropower units, N _W is the number of fans, q _k,t is the output of the kth hydropower unit at time t, P _n,t is the output of the nth thermal power unit at time t, _{pw , t} is the output of the wth wind turbine at time t, h ^t is the number of hours in the t period, a, b, and c are the quadratic coefficient, primary coefficient and constant term of the water consumption function of the thermal power unit, and μ is the hydraulic power The coal consumption rate per unit time of the power plant, λ is the energy consumption coefficient of wind power generation;

The constraint condition establishment unit is used to establish the constraint conditions of the optimal scheduling model of the hydropower-thermal power combined system; the constraints of the optimal scheduling model of the hydropower-thermal power combined system include the power balance constraint condition, the hydropower unit constraint condition and the thermal power unit constraint condition; The constraints of the hydropower unit include the output constraints of the hydropower units, the output limit constraints of the hydropower units and the water balance constraints; the constraints of the thermal power units include the output constraints of the thermal power units, the conventional unit grade limit constraints and the power flow of the power grid branch Restrictions;

The power balance constraints are

Among them, P _Dt is the total load of the combined hydropower station and thermal power plant system;

The output constraints of the hydroelectric unit are:

Among them, V _k,t is the water storage capacity of the kth hydropower unit at time t, Q _k,t is the water output of the hydropower unit, c _1k , c _2k are the secondary water storage capacity and water output in the output constraint of the hydropower unit, respectively term coefficient, c _3k is the first-order coefficient of the product of water storage and water output, c _4k , c _5k are the first-order coefficients of water storage and water output in the output constraint of the hydropower unit, and c _6k is the constant parameter;

The output limit constraints of the hydroelectric unit are:

为第k台水电机组的最小出力，

为第k台水电机组的最大出力；in,

is the minimum output of the kth hydroelectric unit,

is the maximum output of the kth hydroelectric unit;

The water balance constraints are:

表示由于时间延迟存留的水量；R_uk表示第k台水电机组的上游机组的总个数；τ_mk表示上游机组中的第m台水电机组到第k台水电机组的水输送的时间延迟；

表示上游机组中的第m台水电机组由于时间延迟产生的出水量；

表示上游机组中的第m台水电机组由于时间延迟产生的溢水量；Δt表示t-1时刻与t时刻的时间间隔；Among them, V _k,t-1 is the water storage capacity of the kth hydropower unit at time t-1, I _k,t is the water inflow of the kth hydropower unit at time t, and _Qk,t is the kth hydropower unit The water output at time t, S _k,t is the overflow volume of the kth hydropower unit at time t,

Represents the amount of water remaining due to time delay; R _uk represents the total number of upstream units of the k-th hydroelectric unit; τ _mk represents the time delay of water delivery from the m-th hydro-electric unit to the k-th hydro-electric unit in the upstream units;

Represents the water output of the m-th hydropower unit in the upstream unit due to time delay;

Represents the overflow amount of the mth hydropower unit in the upstream unit due to time delay; Δt represents the time interval between time t-1 and time t;

The output limit constraints of the thermal power unit are:

表示第n台火电机组的最小出力，

表示第n台火电机组的最小出力、最大出力；in,

represents the minimum output of the nth thermal power unit,

Indicates the minimum output and maximum output of the nth thermal power unit;

The conventional unit climbing limit constraints are:

p _down,n ≤p _n,t ≤p _up,n ,

Among them, p _down,n represents the maximum down-regulated active power of the nth thermal power unit, and p _up,n represents the maximum up-regulated active power of the nth thermal power unit;

The power flow constraint condition of the power grid branch is:

表示电网中第m条线路的最小潮流，

表示电网中第m条线路的最大潮流，

表示电网中第m条线路在t时刻的潮流。in,

represents the minimum power flow of the mth line in the grid,

represents the maximum power flow of the mth line in the grid,

Represents the power flow of the mth line in the power grid at time t.

Optionally, the solving module specifically includes:

a two-layer model conversion unit, configured to respectively establish a lower-layer hydroelectric generating unit model and an upper-layer thermal generating unit model according to the optimal scheduling model of the hydropower-thermal power combined system;

The first solving unit is used to solve the model of the lower hydroelectric generating unit to obtain the upper boundary value of the output qv of the hydroelectric generating unit and the energy consumption of the hydroelectric generating unit at the ^vth iteration

The obtaining unit is used to obtain the output p ^v-1 of the thermal power unit and the lower boundary value of the energy consumption of the thermal power unit in the v-1 iteration

和第v-1次迭代的火电机组的能耗量的下边界值

是否满足预设收敛条件；若是，则将第v次迭代的水电机组的出力q^v作为水电机组的最优出力，将第v-1次迭代的火电机组的出力p^v-1作为火电机组的最优出力，若否，则转到第二求解单元；所述预设收敛条件为

The judgment unit is used to judge the upper boundary value of the energy consumption of the hydroelectric unit in the vth iteration

and the lower bound value of the energy consumption of the thermal power unit at the v-1th iteration

Whether the preset convergence conditions are met; if so, take the output q ^v of the hydroelectric unit at the vth iteration as the optimal output of the hydroelectric unit, and take the output p ^v-1 of the thermal power unit at the v-1 iteration as the output of the thermal power unit The optimal output, if not, go to the second solving unit; the preset convergence condition is

并令v＝v+1，再返回所述第一求解单元。The second solving unit is used to solve the upper-layer thermal power generating unit model, and obtain the lower boundary value of the output p ^v of the thermal power unit and the energy consumption of the thermal power unit at the vth iteration

And let v=v+1, and then return to the first solving unit.

Compared with the prior art, the beneficial effects of the present invention are:

The invention proposes a cascade hydropower station-thermal power plant joint optimal dispatching method and system. The method includes constructing the output model of the thermal power unit of the thermal power plant in the combined hydro-thermal power system; constructing the optimal scheduling model of the combined hydropower-thermal power system according to the output model of the thermal power unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station and the output of the wind power generating unit; using Benders The decomposition algorithm solves the optimal scheduling model of the hydropower-thermal power combined system, and obtains the optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system; the optimal solution includes the optimal output of the thermal power unit and the optimal output of the hydropower unit; The total energy consumption corresponding to the optimal output of the hydroelectric unit and the optimal output of the hydroelectric unit determines the optimal total energy consumption of the combined hydro-thermal power system. The invention can improve the power generation capacity of clean energy, achieve the purpose of saving the consumption of traditional fossil energy and reducing the emission of air pollutants.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is the flow chart of a kind of cascade hydropower station-thermal power plant joint optimal dispatching method according to the embodiment of the present invention;

2 is a schematic structural diagram of a combined water-thermal-power system according to an embodiment of the present invention;

3 is a schematic structural diagram of a cascade hydropower station-thermal power plant joint optimal dispatching system according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a flow chart of a method for joint optimal scheduling of cascade hydropower stations and thermal power plants according to an embodiment of the present invention.

Referring to Fig. 1, the cascade hydropower station-thermal power plant joint optimal scheduling method of the embodiment includes:

Step S1: Build the output model of the thermal power unit of the thermal power plant in the combined water and thermal power system. The combined water and thermal power system is shown in Figure 2.

The power generation system of the thermal power plant is composed of auxiliary exciter, excitation disk, main exciter (standby exciter), generator, transformer, high-voltage circuit breaker, booster station, power distribution device, etc. Power generation is generated by the high-frequency current from the auxiliary exciter (permanent magnet machine), the current sent by the auxiliary exciter is rectified by the excitation disk, and then sent to the main exciter. to the generator rotor. The generator rotor induces current by rotating its stator coil. The strong current is divided into two paths through the generator outlet, one is sent to the factory power transformer, and the other is sent to the high-voltage circuit breaker, which is sent to the power grid by the high-voltage circuit breaker.

The output model of the thermal power unit of the thermal power plant is specifically:

Among them, N _T represents the number of thermal power units, P _n,t represents the output of the nth thermal power unit at time t, P _Lt represents the total load of the power grid when there are only thermal power units, and ΔP _t is the total loss of the power grid when there are only thermal power units.

Step S2: constructing a hydropower-thermal power combined system optimal scheduling model according to the output model of the thermal power plant, the output of the hydropower set of the cascade hydropower station, and the output of the wind power generating set. Wherein, the output of the hydroelectric unit of the cascade hydropower station may be calculated according to any existing output model of the hydropower unit of the cascade hydropower station, and the output of the wind turbine may also be calculated according to any existing output model of the wind turbine.

The step S2 specifically includes:

Step 21: Taking the minimum total energy consumption of the combined hydropower system as the objective function, establish the objective function of the optimal scheduling model of the combined hydropower-thermal power system

min F _a =F _H +F _T +F _W

in,

Among them, F _a represents the total energy consumption of the combined hydro-thermal power system, F _H represents the energy consumption of the hydropower unit, F _T represents the energy consumption of the thermal power unit, F _W represents the energy consumption of the wind turbine unit, and T is the dispatch time. , N _H is the number of hydropower units, N _W is the number of fans, q _k,t is the output of the kth hydropower unit at time t, P _n,t is the output of the nth thermal power unit at time t, _{pw , t} is the output of the wth wind turbine at time t, h ^t is the number of hours in the t period, a, b, and c are the quadratic coefficient, primary coefficient and constant term of the water consumption function of the thermal power unit, and μ is the hydraulic power The coal consumption rate per unit time of the power plant, λ is the energy consumption coefficient of wind power generation.

Step 22: Establish constraints on the optimal scheduling model of the hydropower-thermal power combined system; the constraints on the optimal scheduling model for the hydropower-thermal power combined system include power balance constraints, hydropower unit constraints, and thermal power unit constraints; the hydropower unit constraints The conditions include output constraints of hydropower units, output limit constraints of hydropower units, and water balance constraints; and the thermal power unit constraints include output constraints of thermal power units, conventional unit climbing constraints, and power grid branch power flow constraints.

Wherein, the power balance constraint condition is:

Among them, P _Dt is the total load of the combined hydropower station and thermal power plant system;

The output constraints of the hydroelectric unit are:

Among them, V _k,t is the water storage capacity of the kth hydropower unit at time t, Q _k,t is the water output of the hydropower unit, c _1k , c _2k are the secondary water storage capacity and water output in the output constraint of the hydropower unit, respectively term coefficient, c _3k is the first-order coefficient of the product of water storage and water output, c _4k , c _5k are the first-order coefficients of water storage and water output in the output constraint of the hydropower unit, and c _6k is the constant parameter;

The output limit constraints of the hydroelectric unit are:

为第k台水电机组的最小出力，

为第k台水电机组的最大出力；in,

is the minimum output of the kth hydroelectric unit,

is the maximum output of the kth hydroelectric unit;

The water balance constraints are:

)表示由于时间延迟存留的水量；R_uk表示第k台水电机组的上游机组的总个数，位于第k台水电机组上游的机组为第k台水电机组的上游机组，第k台水电机组的上游机组中的水电机组从第k+1台开始，共有R_uk台；τ_mk表示上游机组中的第m台水电机组到第k台水电机组的水输送的时间延迟；

表示上游机组中的第m台水电机组由于时间延迟产生的出水量；

表示上游机组中的第m台水电机组由于时间延迟产生的溢水量；Δt表示t-1时刻与t时刻的时间间隔；Among them, V _k,t-1 is the water storage capacity of the kth hydropower unit at time t-1, I _k,t is the water inflow of the kth hydropower unit at time t, and _Qk,t is the kth hydropower unit The water output at time t, S _k,t is the overflow volume of the kth hydropower unit at time t,

) represents the amount of water remaining due to time delay; R _uk represents the total number of upstream units of the kth hydropower unit, the unit located upstream of the kth hydropower unit is the upstream unit of the kth hydropower unit, and the The hydropower units in the upstream unit start from the k+1th unit, and there are a total of R _uk units; τ _mk represents the time delay of water delivery from the mth hydropower unit in the upstream unit to the kth hydropower unit;

Represents the water output of the m-th hydropower unit in the upstream unit due to time delay;

Represents the overflow amount of the mth hydropower unit in the upstream unit due to time delay; Δt represents the time interval between time t-1 and time t;

The output limit constraints of the thermal power unit are:

表示第n台火电机组的最小出力，

表示第n台火电机组的最小出力、最大出力；in,

represents the minimum output of the nth thermal power unit,

Indicates the minimum output and maximum output of the nth thermal power unit;

The conventional unit climbing limit constraints are:

p _down,n ≤p _n,t ≤p _up,n ,

Among them, p _down,n represents the maximum down-regulated active power of the nth thermal power unit, and p _up,n represents the maximum up-regulated active power of the nth thermal power unit;

The power flow constraint condition of the power grid branch is:

表示电网中第m条线路的最小潮流，

表示电网中第m条线路的最大潮流，

表示电网中第m条线路在t时刻的潮流。in,

represents the minimum power flow of the mth line in the grid,

represents the maximum power flow of the mth line in the grid,

Represents the power flow of the mth line in the power grid at time t.

Step S3: use the Benders decomposition algorithm to solve the optimal scheduling model of the hydropower-thermal power combined system, and obtain an optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system; the optimal solution includes the optimal output of the thermal power unit and the optimal output of hydroelectric units.

The step S3 specifically includes:

Step 31: According to the optimal scheduling model of the hydropower-thermal power combined system, a lower-layer hydroelectric generating unit model and an upper-layer thermal generating unit model are established respectively.

Step 32: Solve the lower hydroelectric generating unit model to obtain the upper boundary value of the output q ^v of the hydroelectric generating unit and the energy consumption of the hydroelectric generating unit at the vth iteration

The lower hydroelectric generating unit model is

subjectto

Among them, the constraint condition c(q) represents the constraint of the hydroelectric generating unit, including the output limitation constraint and the water balance constraint of the hydroelectric generating unit, expressed as

The constraint condition d(p,q) represents the coupling constraint of the combined hydropower station and thermal power plant system, which is expressed as

p is assigned as the solution p ^v-1 obtained by the v-1 iteration of the upper thermal power generating unit, that is, p=p ^v-1 . Substitute p into the lower layer model, then the lower layer hydroelectric generating unit model is an optimization problem only about the hydropower generation variable q.

The qv value and the objective function F value are obtained by solving the lower hydroelectric generating unit model. At this time, the F value is defined as the upper boundary of the objective function after the ^vth iteration.

Among them, λ ^v is the bidirectional variable of the output p _i of the thermal power unit in the vth iteration, which is used to correct the constraint feasibility exceeding the limit and increase the sensitivity of the objective function, and λ ^v is expressed as

表示函数F对P_i求偏导。Among them, _NH is the number of hydropower units, _NT is the number of thermal power units, and N _W is the number of fans;

Represents the _partial derivative of the function F with respect to Pi.

Step 33: Obtain the output p ^v-1 of the thermal power unit and the lower boundary value of the energy consumption of the thermal power unit in the v-1 iteration

和第v-1次迭代的火电机组的能耗量的下边界值

是否满足预设收敛条件；若是，则将第v次迭代的水电机组的出力q^v作为水电机组的最优出力，将第v-1次迭代的火电机组的出力p^v-1作为火电机组的最优出力，若否，则执行步骤35；所述预设收敛条件为

Step 34: Determine the upper boundary value of the energy consumption of the hydroelectric unit in the vth iteration

and the lower bound value of the energy consumption of the thermal power unit at the v-1th iteration

Whether the preset convergence conditions are met; if so, take the output q ^v of the hydroelectric unit at the vth iteration as the optimal output of the hydroelectric unit, and take the output p ^v-1 of the thermal power unit at the v-1 iteration as the output of the thermal power unit Optimal output, if not, go to step 35; the preset convergence condition is

更新迭代次数v＝v+1，再返回所述步骤32。其中，所述上层火力发电机组模型为Step 35: Solve the upper-layer thermal power generation unit model, the objective function in the upper-layer thermal power generation unit model is a real variable, and the constraints include thermal power generation unit constraints, and the upper layer thermal power generation unit model is solved to obtain p ^v , and the objective function value lower bound

Update the number of iterations v=v+1, and then return to step 32. Wherein, the upper-layer thermal power generation unit model is

Among them, the constraint condition c(p) represents the constraints of the thermal power generation unit, including the output restriction constraint of the thermal power unit, the unit climbing limit constraint and the power flow constraint of the power grid branch, which is expressed as

Step S4: Determine the optimal total energy consumption of the combined hydro-thermal power system based on the total energy consumption corresponding to the optimal output of the thermal power unit and the optimal output of the hydroelectric unit.

The cascade hydropower station-thermal power combined optimal scheduling method in this embodiment, the hydropower-thermal power combined system optimal scheduling model considers the impact on the wind power consumption of the hydropower-thermal power combined system; the hydropower-thermal power combined system optimal scheduling model takes the minimum total energy consumption as The goal is to achieve a reasonable allocation of resources; the combined hydropower-thermal power system is a multi-dimensional, complex, nonlinear optimization problem, and the traditional optimization algorithm is difficult to calculate. The decomposition optimization algorithm is used to decompose the optimal scheduling model of the hydropower-thermal power combined system Iteratively solves the upper and lower layers alternately, reduces the computational complexity of the system, can quickly converge to the optimal value of the system, and can be used for optimization problems of large-scale large-scale systems in practical projects; It can improve the power generation capacity of clean energy and achieve the goal of saving traditional fossil energy. consumption, the purpose of reducing the emission of air pollutants.

The present invention also provides a cascade hydropower station-thermal power plant joint optimal dispatching system. FIG. 3 is a schematic structural diagram of a cascade hydropower station-thermal power plant joint optimal dispatching system according to an embodiment of the present invention.

Referring to FIG. 3, the cascade hydropower station-thermal power plant joint optimal dispatching system of the embodiment includes:

The first model building module 301 is used to build the output model of the thermal power unit of the thermal power plant in the combined water and thermal power system.

The second model building module 302 is used for constructing a hydropower-thermal power combined system optimal dispatch model according to the output model of the thermal power unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station and the output of the wind power generating unit.

The solving module 303 is used to solve the optimal scheduling model of the hydropower-thermal power combined system by using the Benders decomposition method, and obtain an optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system; the optimal solution includes the Optimal output and optimal output of hydroelectric units.

The energy consumption determination module 304 is configured to determine the optimal total energy consumption of the combined hydrothermal power system based on the total energy consumption corresponding to the optimal output of the thermal power unit and the optimal output of the hydroelectric unit.

As an optional implementation manner, the first model building module 301 is specifically:

Among them, N _T represents the number of thermal power units, P _n,t represents the output of the nth thermal power unit at time t, P _Lt represents the total load of the power grid when there are only thermal power units, and ΔP _t is the total loss of the power grid when there are only thermal power units.

As an optional implementation manner, the second model building module 302 specifically includes:

The objective function establishment unit is used to establish the objective function of the optimal dispatch model of the hydropower-thermal power combined system

minF _a =F _H +F _T +F _W

in,

Among them, F _a represents the total energy consumption of the combined hydro-thermal power system, F _H represents the energy consumption of the hydropower unit, F _T represents the energy consumption of the thermal power unit, F _W represents the energy consumption of the wind turbine unit, and T is the dispatch time. , N _H is the number of hydropower units, N _W is the number of fans, q _k,t is the output of the kth hydropower unit at time t, P _n,t is the output of the nth thermal power unit at time t, _{pw , t} is the output of the wth wind turbine at time t, h ^t is the number of hours in the t period, a, b, and c are the quadratic coefficient, primary coefficient and constant term of the water consumption function of the thermal power unit, and μ is the hydraulic power The coal consumption rate per unit time of the power plant, λ is the energy consumption coefficient of wind power generation;

The constraint condition establishment unit is used to establish the constraint conditions of the optimal scheduling model of the hydropower-thermal power combined system; the constraints of the optimal scheduling model of the hydropower-thermal power combined system include the power balance constraint condition, the hydropower unit constraint condition and the thermal power unit constraint condition; The constraints of the hydropower unit include the output constraints of the hydropower units, the output limit constraints of the hydropower units and the water balance constraints; the constraints of the thermal power units include the output constraints of the thermal power units, the conventional unit grade limit constraints and the power flow of the power grid branch Restrictions;

The power balance constraints are

Among them, P _Dt is the total load of the combined hydropower station and thermal power plant system;

The output constraints of the hydroelectric unit are:

Among them, V _k,t is the water storage capacity of the kth hydropower unit at time t, Q _k,t is the water output of the hydropower unit, c _1k , c _2k are the secondary water storage capacity and water output in the output constraint of the hydropower unit, respectively term coefficient, c _3k is the first-order coefficient of the product of water storage and water output, c _4k , c _5k are the first-order coefficients of water storage and water output in the output constraint of the hydropower unit, and c _6k is the constant parameter;

The output limit constraints of the hydroelectric unit are:

为第k台水电机组的最小出力，

为第k台水电机组的最大出力；in,

is the minimum output of the kth hydroelectric unit,

is the maximum output of the kth hydroelectric unit;

The water balance constraints are:

)表示由于时间延迟存留的水量；R_uk表示第k台水电机组的上游机组的总个数；τ_mk表示上游机组中的第m台水电机组到第k台水电机组的水输送的时间延迟；Q_m,t-τmk表示上游机组中的第m台水电机组由于时间延迟产生的出水量；S_m,t-τmk表示上游机组中的第m台水电机组由于时间延迟产生的溢水量；Δt表示t-1时刻与t时刻的时间间隔；Among them, V _k,t-1 is the water storage capacity of the kth hydropower unit at time t-1, I _k,t is the water inflow of the kth hydropower unit at time t, and _Qk,t is the kth hydropower unit The water output at time t, S _k,t is the overflow volume of the kth hydropower unit at time t,

) represents the amount of water remaining due to time delay; R _uk represents the total number of upstream units of the k-th hydropower unit; τ _mk represents the time delay of water delivery from the m-th hydro-power unit to the k-th hydro-power unit in the upstream units; Q _m,t-τmk represents the water output of the mth hydropower unit in the upstream unit due to time delay; S _m,t-τmk represents the overflow volume of the mth hydropower unit in the upstream unit due to time delay; Δt represents The time interval between time t-1 and time t;

The output limit constraints of the thermal power unit are:

表示第n台火电机组的最小出力，

表示第n台火电机组的最小出力、最大出力；in,

represents the minimum output of the nth thermal power unit,

Indicates the minimum output and maximum output of the nth thermal power unit;

The conventional unit climbing limit constraints are:

p _down,n ≤p _n,t ≤p _up,n ,

Among them, p _down,n represents the maximum down-regulated active power of the nth thermal power unit, and p _up,n represents the maximum up-regulated active power of the nth thermal power unit;

The power flow constraint condition of the power grid branch is:

表示电网中第m条线路的最小潮流，

表示电网中第m条线路的最大潮流，

表示电网中第m条线路在t时刻的潮流。in,

represents the minimum power flow of the mth line in the grid,

represents the maximum power flow of the mth line in the grid,

Represents the power flow of the mth line in the power grid at time t.

As an optional implementation manner, the solving module 303 specifically includes:

a two-layer model conversion unit, configured to respectively establish a lower-layer hydroelectric generating unit model and an upper-layer thermal generating unit model according to the optimal scheduling model of the hydropower-thermal power combined system;

The first solving unit is used to solve the model of the lower hydroelectric generating unit to obtain the upper boundary value of the output qv of the hydroelectric generating unit and the energy consumption of the hydroelectric generating unit at the ^vth iteration

The obtaining unit is used to obtain the output p ^v-1 of the thermal power unit and the lower boundary value of the energy consumption of the thermal power unit in the v-1 iteration

和第v-1次迭代的火电机组的能耗量的下边界值

是否满足预设收敛条件；若是，则将第v次迭代的水电机组的出力q^v作为水电机组的最优出力，将第v-1次迭代的火电机组的出力p^v-1作为火电机组的最优出力，若否，则转到第二求解单元；所述预设收敛条件为

The judgment unit is used to judge the upper boundary value of the energy consumption of the hydroelectric unit in the vth iteration

and the lower bound value of the energy consumption of the thermal power unit at the v-1th iteration

Whether the preset convergence conditions are met; if so, take the output q ^v of the hydroelectric unit at the vth iteration as the optimal output of the hydroelectric unit, and take the output p ^v-1 of the thermal power unit at the v-1 iteration as the output of the thermal power unit The optimal output, if not, go to the second solving unit; the preset convergence condition is

并令v＝v+1，再返回所述第一求解单元。The second solving unit is used to solve the upper-layer thermal power generating unit model, and obtain the lower boundary value of the output p ^v of the thermal power unit and the energy consumption of the thermal power unit at the vth iteration

And let v=v+1, and then return to the first solving unit.

The cascade hydropower station-thermal power plant joint optimal dispatching system in this embodiment can improve the power generation capacity of clean energy, save the consumption of traditional fossil energy, and reduce the emission of air pollutants.

For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (6)

1. a cascade hydropower station-thermal power plant joint optimal dispatch method, is characterized in that, comprises: Build the output model of the thermal power unit of the thermal power plant in the combined water and thermal power system; According to the output model of the thermal power generation unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station and the output of the wind power generation unit, an optimal scheduling model of the hydropower-thermal power combined system is constructed; Benders decomposition algorithm is used to solve the optimal scheduling model of the hydropower-thermal power combined system, and the optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system is obtained; the optimal solution includes the optimal output of the thermal power unit and the hydropower unit. the optimal output; determining the optimal total energy consumption of the combined hydro-thermal power system based on the total energy consumption corresponding to the optimal output of the thermal power unit and the optimal output of the hydroelectric unit; The Benders decomposition algorithm is used to solve the optimal scheduling model of the hydropower-thermal power combined system, and an optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system is obtained, which specifically includes: Step 31: respectively establishing a lower-layer hydroelectric generating unit model and an upper-layer thermal generating unit model according to the optimal scheduling model of the hydropower-thermal power combined system; Step 32: Solve the lower hydroelectric generating unit model to obtain the upper boundary value of the output q ^v of the hydroelectric generating unit and the energy consumption of the hydroelectric generating unit at the vth iteration

Step 33: Obtain the output p ^v-1 of the thermal power unit and the lower boundary value of the energy consumption of the thermal power unit in the v-1 iteration

Step 34: Determine the upper boundary value of the energy consumption of the hydroelectric unit in the vth iteration

and the lower bound value of the energy consumption of the thermal power unit at the v-1th iteration

Whether the preset convergence conditions are met; if so, take the output q ^v of the hydroelectric unit at the vth iteration as the optimal output of the hydroelectric unit, and take the output p ^v-1 of the thermal power unit at the v-1 iteration as the output of the thermal power unit Optimal output, if not, go to step 35; the preset convergence condition is

Step 35: Solve the upper-layer thermal power generation unit model, and obtain the lower boundary value of the output p ^v of the thermal power unit and the energy consumption of the thermal power unit of the v-th iteration

And let v=v+1, and return to step 32. 2. a kind of cascade hydropower station-thermal power plant joint optimal dispatching method according to claim 1, is characterized in that, the output model of described thermal power plant thermal power unit is specially:

Among them, N _T represents the number of thermal power units, P _n,t represents the output of the nth thermal power unit at time t, P _Lt represents the total load of the power grid when there are only thermal power units, and ΔP _t is the total loss of the power grid when there are only thermal power units. 3. a kind of cascade hydropower station-thermal power plant joint optimal dispatching method according to claim 2, is characterized in that, described according to the output model of described thermal power plant thermal power unit, the output of cascade hydropower station hydropower unit and the output of wind power generating unit Build an optimal scheduling model for a combined hydropower-thermal power system, including: Objective Function of Establishing Optimal Scheduling Model for Combined Hydropower and Thermal Power System min F _a =F _H +F _T +F _W in,

Among them, F _a represents the total energy consumption of the combined hydro-thermal power system, F _H represents the energy consumption of the hydropower unit, F _T represents the energy consumption of the thermal power unit, F _W represents the energy consumption of the wind turbine unit, and T is the dispatch time. , N _H is the number of hydropower units, N _T is the number of thermal power units, N _W is the number of fans, q _k,t is the output of the kth hydroelectric unit at time t, P _n,t is the nth unit at time t The output of the thermal power unit, p _{w, t} is the output of the wth wind turbine at time t, h ^t is the number of hours in the t period, a, b, and c are the quadratic term coefficient and primary term of the water consumption function of the thermal power unit, respectively. coefficient and constant term, μ is the coal consumption rate per unit time of the hydropower plant, λ is the energy consumption coefficient of wind power generation; Constraints of the optimal scheduling model of the hydropower-thermal power combined system are established; the constraints of the hydropower-thermal power combined system optimal scheduling model include power balance constraints, hydropower unit constraints, and thermal power unit constraints; the hydropower unit constraints include hydropower Unit output constraints, hydropower unit output limitation constraints, and water balance constraints; the thermal power unit constraints include thermal power unit output limitation constraints, conventional unit ramping constraints, and power grid branch power flow constraints; The power balance constraints are

Among them, P _Dt is the total load of the combined hydropower station and thermal power plant system; The output constraints of the hydroelectric unit are:

Among them, V _k,t is the water storage capacity of the kth hydropower unit at time t, Q _k,t is the water output of the hydropower unit, c _1k , c _2k are the secondary water storage capacity and water output in the output constraint of the hydropower unit, respectively term coefficient, c _3k is the first-order coefficient of the product of water storage and water output, c _4k , c _5k are the first-order coefficients of water storage and water output in the output constraint of the hydropower unit, and c _6k is the constant parameter; The output limit constraints of the hydroelectric unit are:

in,

is the minimum output of the kth hydroelectric unit,

is the maximum output of the kth hydroelectric unit; The water balance constraints are:

Among them, V _k,t-1 is the water storage capacity of the kth hydropower unit at time t-1, I _k,t is the water inflow of the kth hydropower unit at time t, and _Qk,t is the kth hydropower unit The water output at time t, S _k,t is the overflow volume of the kth hydroelectric unit at time t,

Represents the amount of water remaining due to time delay; R _uk represents the total number of upstream units of the k-th hydroelectric unit; τ _mk represents the time delay of water delivery from the m-th hydro-electric unit to the k-th hydro-electric unit in the upstream units;

Represents the water output of the mth hydroelectric unit in the upstream unit due to time delay;

Represents the overflow volume of the mth hydropower unit in the upstream unit due to time delay; Δt represents the time interval between time t-1 and time t; The output limit constraints of the thermal power unit are:

in,

represents the minimum output of the nth thermal power unit,

Indicates the minimum output and maximum output of the nth thermal power unit; The conventional unit climbing limit constraints are: p _down,n ≤p _n,t ≤p _up,n , Among them, p _down,n represents the maximum down-regulated active power of the nth thermal power unit, and p _up,n represents the maximum up-regulated active power of the nth thermal power unit; The power flow constraint condition of the power grid branch is:

in,

represents the minimum power flow of the mth line in the grid,

represents the maximum power flow of the mth line in the grid,

Represents the power flow of the mth line in the power grid at time t. 4. A cascade hydropower station-thermal power plant joint optimal dispatching system is characterized in that, comprising: The first model building module is used to build the output model of the thermal power unit of the thermal power plant in the combined water and thermal power system; The second model building module is used for constructing a hydropower-thermal power combined system optimal dispatch model according to the output model of the thermal power unit of the thermal power plant, the output of the hydropower unit of the cascade hydropower station, and the output of the wind power generating unit; A solving module is used to solve the optimal scheduling model of the hydropower-thermal power combined system by using a decomposition optimization algorithm, and obtain an optimal solution corresponding to the optimal scheduling model of the hydropower-thermal power combined system; the optimal solution includes the optimal solution of the thermal power unit. optimal output and optimal output of hydroelectric units; an energy consumption determination module, configured to determine the optimal total energy consumption of the combined hydro-thermal power system based on the total energy consumption corresponding to the optimal output of the thermal power unit and the optimal output of the hydroelectric unit; The solving module specifically includes: a two-layer model conversion unit, configured to respectively establish a lower-layer hydroelectric generating unit model and an upper-layer thermal generating unit model according to the optimal scheduling model of the hydropower-thermal power combined system; The first solving unit is used to solve the model of the lower hydroelectric generating unit to obtain the upper boundary value of the output qv of the hydroelectric generating unit and the energy consumption of the hydroelectric generating unit at the ^vth iteration

The obtaining unit is used to obtain the output p ^v-1 of the thermal power unit and the lower boundary value of the energy consumption of the thermal power unit in the v-1 iteration

The judgment unit is used to judge the upper boundary value of the energy consumption of the hydroelectric unit in the vth iteration

and the lower bound value of the energy consumption of the thermal power unit at the v-1th iteration

Whether the preset convergence conditions are met; if so, take the output q ^v of the hydroelectric unit at the vth iteration as the optimal output of the hydroelectric unit, and take the output p ^v-1 of the thermal power unit at the v-1 iteration as the output of the thermal power unit The optimal output, if not, go to the second solving unit; the preset convergence condition is

The second solving unit is used to solve the upper-layer thermal power generating unit model, and obtain the lower boundary value of the output p ^v of the thermal power unit and the energy consumption of the thermal power unit at the vth iteration

And let v=v+1, and then return to the first solving unit. 5. a kind of cascade hydropower station-thermal power plant joint optimal dispatching system according to claim 4, is characterized in that, described first model building module is specifically:

Among them, N _T represents the number of thermal power units, P _n,t represents the output of the nth thermal power unit at time t, P _Lt represents the total load of the power grid when there are only thermal power units, and ΔP _t is the total loss of the power grid when there are only thermal power units. 6. a kind of cascade hydropower station-thermal power plant joint optimal dispatching system according to claim 5, is characterized in that, described second model building module, specifically comprises: The objective function establishment unit is used to establish the objective function of the optimal dispatch model of the hydropower-thermal power combined system min F _a =F _H +F _T +F _W in,

Among them, F _a represents the total energy consumption of the combined hydro-thermal power system, F _H represents the energy consumption of the hydropower unit, F _T represents the energy consumption of the thermal power unit, F _W represents the energy consumption of the wind turbine unit, and T is the dispatch time. , N _H is the number of hydropower units, N _W is the number of fans, q _k,t is the output of the kth hydropower unit at time t, P _n,t is the output of the nth thermal power unit at time t, _{pw , t} is the output of the wth wind turbine at time t, h ^t is the number of hours in the t period, a, b, and c are the quadratic coefficient, primary coefficient and constant term of the water consumption function of the thermal power unit, and μ is the hydraulic power The coal consumption rate per unit time of the power plant, λ is the energy consumption coefficient of wind power generation; The constraint condition establishment unit is used to establish the constraint conditions of the optimal scheduling model of the hydropower-thermal power combined system; the constraints of the optimal scheduling model of the hydropower-thermal power combined system include the power balance constraint condition, the hydropower unit constraint condition and the thermal power unit constraint condition; The constraints of the hydropower unit include the output constraints of the hydropower units, the output limit constraints of the hydropower units and the water balance constraints; the constraints of the thermal power units include the output constraints of the thermal power units, the conventional unit grade limit constraints and the power flow of the power grid branch Restrictions; The power balance constraints are

Among them, P _Dt is the total load of the combined hydropower station and thermal power plant system; The output constraints of the hydroelectric unit are:

Among them, V _k,t is the water storage capacity of the kth hydropower unit at time t, Q _k,t is the water output of the hydropower unit, c _1k , c _2k are the secondary water storage capacity and water output in the output constraint of the hydropower unit, respectively term coefficient, c _3k is the first-order coefficient of the product of water storage and water output, c _4k , c _5k are the first-order coefficients of water storage and water output in the output constraint of the hydropower unit, and c _6k is the constant parameter; The output limit constraints of the hydroelectric unit are:

in,

is the minimum output of the kth hydroelectric unit,

is the maximum output of the kth hydroelectric unit; The water balance constraints are:

Among them, V _k,t-1 is the water storage capacity of the kth hydropower unit at time t-1, I _k,t is the water inflow of the kth hydropower unit at time t, and _Qk,t is the kth hydropower unit The water output at time t, S _k,t is the overflow volume of the kth hydropower unit at time t,

Represents the amount of water remaining due to time delay; R _uk represents the total number of upstream units of the k-th hydroelectric unit; τ _mk represents the time delay of water delivery from the m-th hydro-electric unit to the k-th hydro-electric unit in the upstream units;

Represents the water output of the m-th hydropower unit in the upstream unit due to time delay;

Represents the overflow volume of the mth hydropower unit in the upstream unit due to time delay; Δt represents the time interval between time t-1 and time t; The output limit constraints of the thermal power unit are:

in,

represents the minimum output of the nth thermal power unit,

Indicates the minimum output and maximum output of the nth thermal power unit; The conventional unit climbing limit constraints are: p _down,n ≤p _n,t ≤p _up,n , Among them, p _down,n represents the maximum down-regulated active power of the nth thermal power unit, and p _up,n represents the maximum up-regulated active power of the nth thermal power unit; The power flow constraint condition of the power grid branch is:

in,

represents the minimum power flow of the mth line in the grid,

represents the maximum power flow of the mth line in the grid,

Represents the power flow of the mth line in the power grid at time t.

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