CN106156870A - A kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago - Google Patents

Abstract

The invention provides a kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago.The method considers system and runs the conditions such as constraint, unit operation constraint, Network Security Constraints, premised on guaranteeing electric power netting safe running, take into account the energy-saving and environmental protection of generation schedule, economic indicator, formulate the unit generation plan meeting power system security constraints condition, realize peak regulation, frequency modulation, the assistant service such as standby optimize with unit output plan unified Modeling, one, are effectively improved optimality and science that electrical network assistant service arranges.

Description

A kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago

Technical field

The invention belongs to dispatching of power netwoks field, relate to a kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago.

Background technology

The most energy needed for modern society produces and lives are supplied in power system, and correspondingly, this also brings its raw-material a large amount of consumings, and therefore the Optimized Operation to operation of power networks efficiency becomes important research direction.Regularity due to production activity; electric load also presents the characteristic of periodic undulations fluctuation; if not changing the number of start and stop unit only by changing unit output, often in the range of capacity having been switched on unit, it is difficult to met the change of this fluctuation of load by regulation.

In order to realize the equilibrium of supply and demand of electric energy, and the most reasonably utilize generation assets, in advance start and stop and the most important thing being scheduling arranging just to become power generation issues of exerting oneself to generating set.Generally within certain dispatching cycle, it is common that within one day, arrange generation schedule with minimum energy consumption, it is achieved with the balance of given load meet certain constraints and standby requirement.

Operation plan is according to information such as the most accurate system and bus short-term load forecasting, network topologies a few days ago, consider system and run the conditions such as constraint, unit operation constraint, Network Security Constraints, premised on guaranteeing electric power netting safe running, take into account the energy-saving and environmental protection of generation schedule, economic indicator, formulate the unit generation plan meeting power system security constraints condition.It is the important step connecting monthly plan with system real time execution, it it is the nucleus module of decision-making unit generated output next day curve, all kinds of actual motion constraints need to be considered against a rainy day, there is provided enforceability high generation schedule strong, compatible for real time execution, ensure power network safety operation.

Summary of the invention

The invention provides a kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago.The method considers system and runs the conditions such as constraint, unit operation constraint, Network Security Constraints, premised on guaranteeing electric power netting safe running, take into account the energy-saving and environmental protection of generation schedule, economic indicator, formulate the unit generation plan meeting power system security constraints condition, realize peak regulation, frequency modulation, the assistant service such as standby optimize with unit output plan unified Modeling, one, are effectively improved optimality and science that electrical network assistant service arranges.

A kind of based on electrical network planning strategy a few days ago the Real time optimal dispatch method of the present invention, sets up its corresponding mathematical model, comprises the following steps:

S1. with total generating minimum target of expense, the object function of unit output plan based on electrical network Plan rescheduling a few days ago is determined, including fuel used to generate electricity expense with enable expense.

S2. determine in Optimized model, consider unit day Contract generation Constraints of Equilibrium, day part system power Constraints of Equilibrium, the minimum and maximum technology of unit exert oneself restriction, the ramping rate constraints of unit, the constant power operation Contract constraint of part of generating units, the start-off time constraints of unit, system spinning reserve constraint multiple constraints.And calculated regenerative resource interconnection data point is fitted by plan accounting a few days ago.

Accompanying drawing explanation

Fig. 1 is the flow chart of a kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago involved in the present invention.

Detailed description of the invention

As it is shown in figure 1, the specifically comprising the following steps that of a kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago of the present invention

(1) with total generating minimum target of expense, the object function of unit output plan based on electrical network Plan rescheduling a few days ago is determined, including fuel used to generate electricity expense with enable expense.Now, object function is that system always generates electricity expense, and object function is as follows

$\begin{array}{cc}\min & F_1=\underset{t=1}{\overset{T}{\mathrm{\Σ}}}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}(f_i\left(P_{t,i}\right)\mathrm{\τ}+f_{\mathrm{si}}{u}_{i,t}(1-u_{i,t-1}))\end{array}$ Formula 1

In formula, T is scheduling day total time hop count；

N is system unit sum；

τ is the persistent period of each period；

P_{i , t}Exert oneself at the meritorious of period t for unit i, wherein

P_{i ,}T=M_{i , t}-J_{i , t}Formula 2

M_{i , t}For unit installed capacity, J_{i , t}For repair schedule capacity；

f_iFor the cost of electricity-generating function of unit i, quadratic function form is generally used to be expressed as

f_i(P_{i , t})=a_t(P_{i , t})²+b_iP_{i , t}+c_iFormula 3

a_i, b_i, c_iIt is respectively the quadratic term of unit i cost coefficient, first order and constant term coefficient；

f_siStart-up cost for unit i；

u_{i , t}For unit i in the running status of period t, during operation, its value is 1, is 0 during stoppage in transit；

(2) determine in Optimized model, consider unit day Contract generation Constraints of Equilibrium, day part system power Constraints of Equilibrium, the minimum and maximum technology of unit exert oneself restriction, the constraint of the ramping rate constraints of unit, the constant power operation Contract constraint of part of generating units, the start-off time constraints of unit, system spinning reserve and the plan multiple constraints of accounting a few days ago.

1. unit day Contract generation Constraints of Equilibrium is:

$S_{i\min }\≤\mathrm{\τ}\underset{t=1}{\overset{T}{\mathrm{\Σ}}}{P}_{i,t}\≤A_{i\max },i\∈S_{\mathrm{GCON}}$ Formula 4

In formula, A_iminAnd A_imaxIt is respectively the minimum and maximum day delivery of power plant/unit i；S_GCONFor possessing the unit set of Contract generation day decomposition value constraint.

In present stage, grid company and power plant typically sign year electricity contract or moon electricity contract.When being embodied as, needing by grid company according to electrical network month or daily load prediction data, consider the situations such as maintenance, the method for operation, the principle substantially equalized by each power plant long-term contract electricity schedule decomposes day, then formulates daily trading planning.For causing, due to reasons such as load prediction deviations, the part that performs the most according to plan, then carry out rolling of electricity and adjust the concordance ensureing to be finally completed progress.

A_iminAnd A_imaxCan be at the day decomposition value A of the annual and monthly Contract generation of unit i_iOn the basis of suitably loosen and obtain (such as ± 1%), thus as the inequality constraints of daily trading planning, relative in other document using this constraint as an equality constraint, i.e. limit daily generation equal to a certain set-point, model is that generation schedule provides looser optimizing condition herein, can realize the concordance of long-term contract electricity schedule in conjunction with the adjustment that rolls of electricity simultaneously.

2. day part system power Constraints of Equilibrium is:

$\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{P}_{i,t}=P_{D,t}t=\mathrm{1,2},...,T$ Formula 5

In formula, P_{D , t}It it is the system loading of t period.

3. the minimum and maximum technology of unit is exerted oneself restriction:

u_{i , t}P_imin≤P_{i , t}≤u_{i , t}P_imax, t=1,2 ..., T, i=1,2 ..., N formula 6

In formula, P_iminAnd P_imaxThe minimum and maximum technology being respectively unit i is exerted oneself.

4. the ramping rate constraints of unit

-τR_{d , i}≤P_{i , t}-P_{i , t-1}≤τR_{u , i}, t=1,2 ..., T, i=1,2 ..., N formula 7

In formula, R_{u , i}And R_{d , i}It is respectively the maximum raising and lowering speed of unit i active power output, unit MW/min.

5. the constant power operation Contract constraint of part of generating units, it is desirable to these units, by the Power operation determined, are not involved in unit output and adjust.

P_{i , t}=constant, t=1,2 ..., T, i ∈ S_PCONSTFormula 8

In formula, S_PCONSTFor having the unit set of invariable power constraint, equivalent outsourcing power supply typically has such requirement.

6. the start-off time constraints of unit

T_on(i)≥T_minon(i), T_off(i)≥T_minoff(i), i=1,2 ..., N formula 9

In formula, T_on(i)For the continuous operating time of unit i, unit h (hour)；T_minon(i)Minimum continuous operating time for unit i；T_off(i)Continuous downtime for unit i；T_minoff(i)Minimum downtime continuously for unit i.

7. system spinning reserve constraint

$\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{u}_{i,t}{P}_{i\max }\≥P_{D,t}+P_R,t=\mathrm{1,2},...,T$ Formula 10

In formula, P_RFor system spinning reserve capacity, simple method is to take system to put into certain percent of total capacity, and accurate method then calculates according to the reliability index of system.

Plan accounting the most a few days ago

$\left(\begin{array}{c}{r}_n=P_{D,t,n}/P_{i,t,n},t=\mathrm{1,2},...,T\\ \max r_n,{\stackrel{\&CenterDot;}{P}}_{D,t}<0\\ {\min r}_n,{\stackrel{\&CenterDot;}{P}}_{D,t}>0\end{array}\right.$ Formula 11

I.e. when needs raise unit, the preferential plan accounting a few days ago that raises is low, and when unit lowered by needs, preferential regulation plan accounting a few days ago is high.

Claims (3)

1. a Real time optimal dispatch method based on electrical network planning strategy a few days ago, it is characterised in that comprise the steps:

S1. with total generating minimum target of expense, the object function of unit output plan based on electrical network Plan rescheduling a few days ago is determined, including fuel used to generate electricity expense with enable expense.Based on future load predictive value and local unit generated output plan, it is calculated initial contact line plan；

S2. determine in Optimized model, consider unit day Contract generation Constraints of Equilibrium, day part system power Constraints of Equilibrium, the minimum and maximum technology of unit exert oneself restriction, the multiple constraints of the ramping rate constraints of unit, the constant power operation Contract constraint of part of generating units, the start-off time constraints of unit, system spinning reserve constraint.And calculated regenerative resource interconnection data point is fitted by plan accounting a few days ago.

A kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago the most according to claim 1 is characterized in that the object function of the unit output plan described in S1, and its computing formula is:

Formula 1

In formula, T is scheduling day total time hop count；

N is system unit sum；

τ is the persistent period of each period；

P_{i , t}Exert oneself at the meritorious of period t for unit i, wherein

P_{i , t}=M_{i , t}-J_{i , t}Formula 2

M_{i , t}For unit installed capacity, J_{i , t}For repair schedule capacity；

f_iFor the cost of electricity-generating function of unit i, quadratic function form is generally used to be expressed as

f_i(P_{i , t})=a_i(P_{i , t})²+b_iP_{i , t}+c_iFormula 3

a_i, b_i, c_iIt is respectively the quadratic term of unit i cost coefficient, first order and constant term coefficient；

f_siStart-up cost for unit i:

u_{i , t}For unit i in the running status of period t, during operation, its value is 1, is 0 during stoppage in transit；

A kind of Real time optimal dispatch method based on electrical network planning strategy a few days ago the most according to claim 1 is characterized in that the multiple constraints described in S1, and its computing formula is:

1. unit day Contract generation Constraints of Equilibrium is:

Formula 4

In formula, A_iminAnd A_imaxIt is respectively the minimum and maximum day delivery of power plant/unit i；S_GCONFor possessing the unit set of Contract generation day decomposition value constraint.

2. day part system power Constraints of Equilibrium is:

Formula 5

In formula, P_{D , t}It it is the system loading of t period.

3. the minimum and maximum technology of unit is exerted oneself restriction:

u_{i , t}P_imin≤P_{i , t}≤u_{i , t}P_imax, t=1,2 ..., T, i=1,2 ..., N formula 6

In formula, P_iminAnd P_imaxThe minimum and maximum technology being respectively unit i is exerted oneself.

4. the ramping rate constraints of unit

-τR_{d , i}≤P_{i , t}-P_it-1≤τR_{u , i}, t=1,2 ..., T, i=1,2 ..., N formula 7

In formula, R_{u , i}And R_{d , i}It is respectively the maximum raising and lowering speed of unit i active power output, unit MW/min.

5. the constant power operation Contract constraint of part of generating units, it is desirable to these units, by the Power operation determined, are not involved in unit output and adjust.

P_{i , t}=constant, t=1,2 ..., T, i ∈ S_PCONSTFormula 8

In formula, S_PCONSTFor having the unit set of invariable power constraint, equivalent outsourcing power supply typically has such requirement.

6. the start-off time constraints of unit

T_on(i)≥T_minon(i), T_off(i)≥T_minoff(i), i=1,2 ..., N formula 9

In formula, T_on(i)For the continuous operating time of unit i, unit h (hour)；T_minon(i)Minimum continuous operating time for unit i；T_off(i)Continuous downtime for unit i；T_minoff(i)Minimum downtime continuously for unit i.

7. system spinning reserve constraint

Formula 10

In formula, P_RFor system spinning reserve capacity, simple method is to take system to put into certain percent of total capacity, and accurate method then calculates according to the reliability index of system.

Plan accounting constraint the most a few days ago

Formula 11

I.e. when needs raise unit, the preferential plan accounting a few days ago that raises is low, and when unit lowered by needs, preferential regulation plan accounting a few days ago is high.