CN102684201A - Voltage threshold probability-based reactive power optimizing method for grid containing wind power plant - Google Patents

Abstract

The invention provides a voltage threshold probability-based reactive power optimizing method for a grid containing a wind power plant, which aims to solve the problem that under the condition of wind power networking, the effect of the voltage optimizing control to an automatic voltage control system is not ideal. The method comprises the steps as follows: firstly, collecting grid operation parameters, basic parameters of each wind power generator in the wind power plant, and active power output data of the wind power plant; secondly, acquiring voltage impact factor, power conversion coefficient of the wind power generators and wind power plant active power probability distribution equation through the above parameters, and further obtaining voltage threshold probability; and lastly, establishing a reactive power optimizing model on the basis of the voltage threshold probability, adopting genetic algorithm to solve the model, and obtaining a control instruction of a reactive power device. According to the invention, the voltage threshold probability-based reactive power optimizing method substitutes a conventional reactive power optimizing method for the automatic voltage control system, can enable the voltage optimizing control to the automatic voltage control system to effectively control the reactive power device in the grid under the condition of wind power networking, and ensure the safe and economic operation of the grid.

Description

A kind ofly contain wind energy turbine set reactive power optimization method based on the out-of-limit probability of voltage

Technical field

The present invention relates to the idle operation method of electric power system, particularly a kind of electric network reactive-load operation method that comprises wind energy turbine set.

Background technology

Insert the increase of quantity and capacity along with wind energy turbine set; The randomness of wind power and intermittence will be brought fluctuation more fast to system voltage; The automatic voltage control system that calculates based on the timing idle work optimization will receive very big influence and frequent operation, often not reach the effect of decreasing and guaranteeing quality of voltage of falling of its expection.

Specifically, the control strategy of area power grid automatic voltage control system is made up of the strategy of correction on the spot that starts the at any time regional idle work optimization control strategy that (such as every separated 15-30 minute) starts with regularly usually.The latter normally calculates and controls to the current time section of electrical network, and the voltage control of guiding whole day realizes the excellent control that becomes of saving energy and decreasing loss, during the local voltage that takes place is out-of-limit then goes adjustment by proofreading and correct tactful part on the spot.If the voltage fluctuation degree is less in this cycle, then automatic voltage control system can be taken into account the whole day saving energy and decreasing loss, guarantees that voltage is qualified and avoid the economy and the fail safe needs of equipment frequent operation.Yet the fluctuation of wind power is more complicated than load fluctuation property, more acutely, more frequent.Because pursuing the result fall damage, idle work optimization often cause part of nodes voltage to level off to the upper voltage limit operation; Receive the exert oneself influence of quick frequent fluctuation of wind-powered electricity generation; The voltage of these nodes will fluctuate continually and is out-of-limit every now and then, causes the frequent operation of regulating and controlling voltage equipment and influences its service life, increases system's operation risk.

The present invention is converted into the out-of-limit probability of voltage to the probability distribution equation of wind energy turbine set power and is incorporated in the reactive power optimization that contains wind energy turbine set; Thereby improved the validity of automatic voltage control system idle work optimization; Idle work optimization can be brought into play in comprising the electrical network of wind energy turbine set fall the effect of decreasing and guaranteeing quality of voltage, make electrical network can admit more clean wind energy generating.

Summary of the invention

In order to solve the problem of decreasing and guaranteeing quality of voltage of falling that wind farm grid-connected down traditional idle work optimization can not play expection, make electrical network can admit more wind power generation, the present invention proposes and contain wind energy turbine set reactive power optimization method based on the out-of-limit probability of voltage.

A kind of based on the out-of-limit probability of voltage contain wind energy turbine set reactive power optimization method, may further comprise the steps:

(1) force data of gaining merit of the blower foundation parameter of collection operation of power networks parameter, each wind energy turbine set and the long-time section of wind energy turbine set; The operation of power networks parameter comprises: power network topology, line parameter circuit value, transformer station's parameter, load parameter, generator parameter, node voltage allow range of operation, reactive-load compensation equipment parameter, node serial number set N and wind energy turbine set numbering set W; Power network topology refers to the connected mode of circuit and circuit, circuit and transformer in the electrical network, and the line parameter circuit value of each bar circuit comprises circuit unit resistance r _o, the reactance x of circuit unit _Lo, the susceptance X of circuit unit _CoWith line length L; Transformer station's parameter comprises the transformer number n _T, the equivalent resistance r of each transformer _T, equivalent reactance x _T, transformer equivalent no-load voltage ratio k _T, no-load voltage ratio upper limit k _MaxWith no-load voltage ratio lower limit k _MinThe load parameter of each node includes workload P _LNWith load or burden without work Q _LNGenerator parameter comprises as the active power of traditional power plant of PV node (meritorious exert oneself and be incorporated into the power networks the controlled node of busbar voltage) and voltage, as the active power of traditional power plant of PQ node (meritorious exerting oneself and the idle controlled node of exerting oneself) and reactive power and as the voltage and the phase angle of traditional power plant of V θ node (node that voltage and phase angle are controlled); The node voltage allowed band comprises that node voltage allows upper limit V _MaxAllow lower limit V with node voltage _MinThe reactive-load compensation equipment parameter comprises that the capacitor group of each node counts n _CWith every pool-size n _Co, each node the reactor group count n _LWith every pool-size n _LoThe underlying parameter of each wind electric field blower comprises the rated power P of blower fan _N, incision wind speed v _In, cut-out wind speed v _Out, rated wind speed v _NWith wind sweeping area A;

(2) through operation of power networks calculation of parameter electric network swim, obtain the voltage influence factor, i.e. local voltage factor of influence K _IjWith overall voltage influence factor K _iCalculate the power conversion coefficient C of blower fan through the underlying parameter of blower fan _pAsk for the dimensional parameters c and the form parameter k of the meritorious probability distribution equation of wind energy turbine set through gain merit force data and the least square fitting of wind energy turbine set; The voltage influence factor K _IjAnd K _i, the power conversion coefficient C of blower fan _pCan be used for the out-of-limit probability of computing node voltage with meritorious probability distribution equation;

(3) be target function with net damage and the peaked weighted sum of the out-of-limit probability of node voltage; With power flow equation, node voltage range of operation; Exert oneself the range constraint of transferring the files with transformer of the scope of exerting oneself that reactive power source is idle, reactive-load compensation equipment idle is that constraints is built and contained wind energy turbine set idle work optimization model based on the out-of-limit probability of voltage;

(4) adopt genetic algorithm for solving to contain wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage; Automatic voltage control system is controlled the action of reactive apparatus according to the control command of sending reactive apparatus based on the solving result that contains wind energy turbine set reactive power optimization model of the out-of-limit probability of voltage.

Above-mentioned containing in the wind energy turbine set reactive power optimization method based on the out-of-limit probability of voltage; It is according to given power network topology, line parameter circuit value, transformer station's parameter and generator parameter, load parameter that said trend is calculated, and confirms the calculating of meritorious, idle, the voltage and the phase angle of each node of electrical network through mathematical computations.It is the most basic calculating of power system analysis that trend is calculated.

Above-mentioned based on the containing in the wind energy turbine set reactive power optimization method of the out-of-limit probability of voltage, the said voltage influence factor refers to the influence degree of wind energy turbine set to a certain grid nodes voltage.The voltage influence factor is divided two kinds: i.e. local voltage factor of influence K _IjWith overall voltage influence factor K _iBoth relations do

$K_i=n_W/\left(\underset{j\∈W}{\mathrm{\Σ}}\frac{1}{K_{\mathrm{ij}}}\right)---\left(1\right)$

Local voltage factor of influence K _IjFor wind energy turbine set j acts on down separately, cause the active power variable quantity of the wind energy turbine set j that per unit node i voltage variety is required.Each wind energy turbine set is carried out twice trend calculate, the operation of power networks parameter that twice trend calculated remains unchanged, and calculates wind energy turbine set zero for the first time and sends out, and calculates that wind energy turbine set is completely sent out for the second time and with given hysteresis firm power factor φ operation, then local voltage factor of influence K _IjComputational methods do

$K_{\mathrm{ij}}=\frac{P_{\mathrm{jN}}}{\mathrm{\Δ}{V}_{\mathrm{ijMax}}}---\left(2\right)$

In the formula, P _JNInstalled capacity for wind energy turbine set j; Δ V _IjMaxVoltage variety for twice trend calculating of node i.

Overall situation voltage influence factor K _iReferring in all wind energy turbine set influences down simultaneously, causes total active power variable quantity of all wind energy turbine set that per unit node i voltage variety is required.

Above-mentioned based on the containing in the wind energy turbine set reactive power optimization method of the out-of-limit probability of voltage, it is characterized in that: said power conversion coefficient C _pRefer to the ratio of blower fan electromagnetic power and wind wheel mechanical output.Can obtain by the following formula estimation.

$C_p=\frac{{2P}_N}{\mathrm{\ρA}{v}_N^3}---\left(3\right)$

Above-mentioned the meritorious probability distribution equation of said wind energy turbine set refers to the meritorious probability expression of exerting oneself of wind energy turbine set based on the containing in the wind energy turbine set reactive power optimization method of the out-of-limit probability of voltage, and its expression formula does

$\mathrm{\&beta;}\left(P\right)=\left\{\begin{array}{cc}1-\exp [-{\left(\frac{v_{\mathrm{in}}}{c}\right)}^k]+\exp [-{\left(\frac{v_{\mathrm{out}}}{c}\right)}^k]& (0\&le;P<P_1)\\ 1-\exp [-{\left(\frac{v_p}{c}\right)}^k]+\exp [-{\left(\frac{v_{\mathrm{out}}}{c}\right)}^k]& ({\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="120530094529.png,120530094548.png"\; state="\{\{state\}\}">P</figure-callout>}}_1\&le;P<P_N)\\ 1& (P=P_N)\end{array}\right.---\left(4\right)$

In the formula, P is that the meritorious of blower fan exerted oneself; P ₁For wind speed is v _InThe meritorious of Shi Fengji exerted oneself; v _pFor exerting oneself P less than rated power and greater than P when blower fan is meritorious ₁The meritorious P corresponding air speed of exerting oneself of Shi Fengji.v _pComputational methods do

$v_p=\sqrt[3]{\frac{2P}{C_P\mathrm{A\&rho;}}}---\left(5\right)$

In the formula, C _pBe the wind energy conversion efficiency, ρ is the atmospheric density at wind wheel hub height place, and A is the wind wheel wind sweeping area.

Above-mentioned containing in the wind energy turbine set reactive power optimization method based on the out-of-limit probability of voltage; The out-of-limit probability of said voltage refers under the steady state condition; In a control cycle of automatic voltage control system, out-of-limit probability takes place in the node voltage of electrical network wind-engaging influence.The out-of-limit probability of voltage divides two kinds: the out-of-limit probability β of local voltage _IjWith the out-of-limit probability β of overall voltage _i

The out-of-limit probability β of local voltage _IjRefer to the out-of-limit probability of voltage takes place when node i is influenced separately by wind energy turbine set j.If node i voltage allows intermediate value V _i ⁰Allow the intermediate value of range of operation for node voltage.Promptly

${V_i}^0=\frac{1}{2}(V_{\mathrm{iMin}}+V_{i\max })---\left(6\right)$

In the formula, V _ImaxNode i voltage allows the upper limit and V _IminNode i voltage allows lower limit.

When node i voltage allows upper limit V _IMaxVoltage variety Δ V with twice trend calculating of node i _IjMaxAbsolute difference allow intermediate value V greater than node i voltage _i ⁰The time, the out-of-limit probability β of local voltage _IjFor

In the formula, n _jBe wind energy turbine set j blower fan number,

Referring to will

Substitution (4) in P calculate,

Referring to will

P in the substitution (4) calculates;

When node i voltage allows upper limit V _IMaxVoltage variety Δ V with twice trend calculating of node i _IjMaxAbsolute difference allow intermediate value V less than node i voltage _i ⁰The time, the out-of-limit probability β of local voltage _IjFor

In the formula; refers to the P in the substitution (4) of

calculated,

refer to the P in

substitution (4) calculated;

Therefore, the out-of-limit probability β of the overall voltage of node i _iFor

${\mathrm{\&beta;}}_i=\frac{K_i}{n_W}\underset{j\&Element;W}{\mathrm{\&Sigma;}}\frac{{\mathrm{\&beta;}}_{\mathrm{ij}}}{K_{\mathrm{ij}}}---\left(9\right)$

Above-mentioned based on the containing in the wind energy turbine set reactive power optimization method of the out-of-limit probability of voltage, the said wind energy turbine set reactive power optimization model that contains based on the out-of-limit probability of voltage comprises target function constraints two parts.

The target function that contains wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage does

$\min f={\mathrm{\&omega;}}_1{P}_L+{\mathrm{\&omega;}}_2\underset{i\&Element;N}{\mathrm{Max}}{\mathrm{\&beta;}}_i---\left(10\right)$

In the formula, P _LFor net decreases, The maximum of the out-of-limit probability of all node overall situation voltages is found the solution in expression.ω ₁, ω ₂Be weight coefficient, span is 0 ~ 1, gets ω generally speaking ₁Be 0.2, ω ₂Be 0.8.Net decreases P _LComputational methods do

$P_L=\underset{i\&Element;N,j\&Element;N}{\mathrm{\&Sigma;}}{\left|\frac{V_i-V_j}{r_{\mathrm{oij}}+x_{\mathrm{Loij}}}\right|}^2\frac{r_{\mathrm{oij}}}{L_{\mathrm{ij}}}---\left(11\right)$

In the formula, V _iAnd V _jBe respectively the voltage of i node and j node.r _OijBe circuit unit resistance, the x between node i and the node j _LoijBe the circuit unit's reactance between node i and the node j, L _IjBe the line length between node i and the node j.

The constraints that contains wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage is power flow equation constraint, the constraint of node voltage allowed band; The generator reactive range constraint of exerting oneself, the range constraint of transferring the files of idle the exert oneself constraint and the transformer of reactive-load compensation equipment.

Above-mentioned based on the containing in the wind energy turbine set reactive power optimization method of the out-of-limit probability of voltage, said genetic algorithm is a kind of intelligent search algorithm of solving-optimizing model optimal solution commonly used.

Contain the wind energy turbine set idle work optimization method and compare with existing, the present invention has following advantage:

(1) the present invention has taken into full account the randomness and intermittent influence to line voltage control of wind power, has proposed wind energy turbine set the influence out-of-limit probability of voltage and the computational methods thereof of grid nodes down first.

(2) the present invention is incorporated into the out-of-limit probability of grid nodes voltage in the modeling of reactive power optimization method; Idle work optimization method is improved the adaptability of wind power greatly, make idle work optimization method under wind farm grid-connected, still can play the effect of decreasing and guaranteeing quality of voltage of falling.

(3) institute of the present invention extracting method is applied in the existing regional idle work optimization control module of automatic voltage control system, to replace its original idle work optimization method, need not the hardware configuration of automatic voltage control system itself is made amendment.Method practical is prone to promote.

Description of drawings

Fig. 1 is based on the schematic flow sheet that contains wind energy turbine set reactive power optimization method of the out-of-limit probability of voltage.

Fig. 2 is certain urban distribution network sketch map.

Fig. 3 is the long-time meritorious sketch map of exerting oneself of wind energy turbine set Y.

Fig. 4 is that wind energy turbine set Y has actual work exert oneself probability distribution and match sketch map.

Fig. 5 a, Fig. 5 b adopt the wind energy turbine set reactive power optimization method that contains based on the out-of-limit probability of voltage to be optimized before the control and 110kV line voltage distribution map after the optimal control.

Fig. 6 a, Fig. 6 b adopt the wind energy turbine set reactive power optimization method that contains based on the out-of-limit probability of voltage to be optimized before the control and the out-of-limit probability graph of voltage after the optimal control.

Embodiment

Below in conjunction with accompanying drawing and instance practical implementation of the present invention is further specified, but enforcement of this explanation and protection are not limited thereto.

The wind energy turbine set reactive power optimization method that contains based on the out-of-limit probability of voltage comprises:

(1) gathers the operation of power networks parameter, the force data of gaining merit of the long-time section of the blower foundation parameter of each wind energy turbine set and wind energy turbine set.The operation of power networks parameter comprises: power network topology, line parameter circuit value, transformer station's parameter, load parameter, generator parameter, node voltage allow range of operation, reactive-load compensation equipment parameter, node serial number collection N and wind energy turbine set numbering W.Power network topology refers to the connected mode of circuit and circuit, circuit and transformer in the electrical network.The line parameter circuit value of each bar circuit comprises circuit unit resistance r _o, the reactance x of circuit unit _Lo, the susceptance X of circuit unit _CoWith line length L.Transformer station's parameter of each transformer station comprises the transformer number n _T, the equivalent resistance r of each transformer _T, equivalent reactance x _T, transformer equivalent no-load voltage ratio k _T, no-load voltage ratio upper limit k _MaxWith no-load voltage ratio lower limit k _MinThe load parameter of each node includes workload P _LNWith load or burden without work Q _LNGenerator parameter comprises as the active power of traditional power plant of PV node and voltage, as the active power of traditional power plant of PQ node and reactive power and as the voltage and the phase angle of traditional power plant of V θ node.The node voltage allowed band comprises that node voltage allows upper limit V _MaxAllow lower limit V with node voltage _MinThe reactive-load compensation equipment parameter comprises that the capacitor group of each node counts n _CWith every pool-size n _Co, each node the reactor group count n _LWith every pool-size n _LoThe underlying parameter of each wind electric field blower comprises the rated power P of blower fan _N, incision wind speed v _In, cut-out wind speed v _Out, rated wind speed v _N, wind sweeping area A.

(2) through operation of power networks calculation of parameter electric network swim, obtain the voltage influence factor, i.e. local voltage factor of influence K _IjWith overall voltage influence factor K _iCalculate the power conversion coefficient C of blower fan through the underlying parameter of blower fan _pAsk for the dimensional parameters c and the form parameter k of the meritorious probability distribution equation of wind energy turbine set through gain merit force data and the least square fitting of wind energy turbine set; The voltage influence factor K _IjAnd K _i, the power conversion coefficient C of blower fan _pCan be used for the out-of-limit probability of computing node voltage with meritorious probability distribution equation.

It is the most basic calculating of power system analysis that trend is calculated.Trend is calculated according to given power network topology, line parameter circuit value, transformer station's parameter and generator parameter, load parameter, confirms meritorious, idle, the voltage and the phase angle of each node of electrical network through mathematical computations.

The voltage influence factor refers to the influence degree of wind energy turbine set to a certain grid nodes voltage.The voltage influence factor is divided two kinds: i.e. local voltage factor of influence K _IjWith overall voltage influence factor K _i

Local voltage factor of influence K _IjFor wind energy turbine set j acts on down separately, cause the active power variable quantity of the wind energy turbine set j that per unit node i voltage variety is required.Each wind energy turbine set is carried out twice trend to be calculated; The operation of power networks parameter of twice trend calculating remains unchanged, and wind energy turbine set is moved with given hysteresis firm power factor φ, calculates wind energy turbine set zero for the first time and sends out (promptly meritorious exerting oneself is 0); For the second time calculate wind energy turbine set and completely send out, then local voltage factor of influence K _IjComputational methods do

$K_{\mathrm{ij}}=\frac{P_{\mathrm{jN}}}{\mathrm{\&Delta;}{V}_{\mathrm{ijMax}}}$

In the formula, P _JNInstalled capacity for wind energy turbine set j; Δ V _IjMaxVoltage variety for twice trend calculating of node i.

Overall situation voltage influence factor K _iReferring in all wind energy turbine set influences down simultaneously, causes total active power variable quantity of all wind energy turbine set that per unit node i voltage variety is required.It and local voltage factor of influence K _IjRelation do

$K_i=n_W/\left(\underset{j\&Element;W}{\mathrm{\&Sigma;}}\frac{1}{K_{\mathrm{ij}}}\right)$

Power conversion coefficient C _pRefer to the ratio of blower fan electromagnetic power and wind wheel mechanical output.Can obtain by the following formula estimation.

$C_p=\frac{2P_N}{\mathrm{\&rho;A}{\mathrm{<figure-callout\; id="3"\; label="v\; N"\; filenames="120530094529.png"\; state="\{\{state\}\}">v</figure-callout>}}_N^{}}$

Further introduce the meritorious probability distribution equation of wind energy turbine set, ρ is the atmospheric density at wind wheel hub height place, and A is the wind wheel wind sweeping area, P _NBe the rated power of blower fan, v _NRated wind speed for blower fan.

The meritorious probability distribution equation of wind energy turbine set refers to the meritorious probability expression of exerting oneself of wind energy turbine set, and its expression formula does

$\mathrm{\&beta;}\left(P\right)=\left\{\begin{array}{cc}1-\exp [-{\left(\frac{v_{\mathrm{in}}}{c}\right)}^k]+\exp [-{\left(\frac{v_{\mathrm{out}}}{c}\right)}^k]& (0\&le;P<P_1)\\ 1-\exp [-{\left(\frac{v_p}{c}\right)}^k]+\exp [-{\left(\frac{v_{\mathrm{out}}}{c}\right)]}^k& ({\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="120530094529.png,120530094548.png"\; state="\{\{state\}\}">P</figure-callout>}}_1\&le;P<P_N)\\ 1& (P=P_N)\end{array}\right.$

In the formula, P is that the meritorious of blower fan exerted oneself; P ₁For wind speed is v _InThe meritorious of Shi Fengji exerted oneself; v _pFor exerting oneself P less than rated power and greater than P when blower fan is meritorious ₁The meritorious P corresponding air speed of exerting oneself of Shi Fengji.v _pComputational methods do

$v_p=\sqrt[3]{\frac{2P}{C_P\mathrm{A\&rho;}}}$

In the formula, C _pBe the wind energy conversion efficiency, ρ is the atmospheric density at wind wheel hub height place, and A is the wind wheel wind sweeping area.

The power conversion coefficient C of blower fan _pCan be used for the out-of-limit probability of computing node voltage with the meritorious probability distribution equation of wind energy turbine set.Hereinafter is introduced the implication and the computational methods of the out-of-limit probability of voltage.

The out-of-limit probability of voltage refers under the steady state condition, and in a control cycle of automatic voltage control system, out-of-limit probability takes place the node voltage of electrical network wind-engaging influence.The out-of-limit probability of voltage divides two kinds: the out-of-limit probability β of local voltage _IjWith the out-of-limit probability β of overall voltage _i

The out-of-limit probability β of local voltage _IjRefer to the out-of-limit probability of voltage takes place when node i is influenced separately by wind energy turbine set j.If node i voltage allows intermediate value V _i ⁰Allow the intermediate value of range of operation for node voltage.Promptly

${{\mathrm{<figure-callout\; id="0"\; label="V\; i"\; filenames="120530094529.png,120530094537.png"\; state="\{\{state\}\}">V</figure-callout>}}_i}^0=\frac{1}{2}(V_{\mathrm{iMin}}+V_{i\max })$

In the formula, V _ImaxNode i voltage allows the upper limit and V _IminNode i voltage allows lower limit.

When node i voltage allows upper limit V _IMaxVoltage variety Δ V with twice trend calculating of node i _IjMaxAbsolute difference allow intermediate value V greater than node i voltage _i ⁰The time, the out-of-limit probability β of local voltage _IjFor

In the formula, n _jBe wind energy turbine set j blower fan number,

Referring to will

Substitution (4) in P calculate,

Referring to will

P in the substitution (4) calculates;

When node i voltage allows upper limit V _IMaxVoltage variety Δ V with twice trend calculating of node i _IjMaxAbsolute difference allow intermediate value V less than node i voltage _i ⁰The time, the out-of-limit probability β of local voltage _IjFor

In the formula;

refers to the P in the substitution (4) of

calculated,

refer to the P in

substitution (4) calculated;

Therefore, the out-of-limit probability β of the overall voltage of node i _iFor

${\mathrm{\&beta;}}_i=\frac{K_i}{n_W}\underset{j\&Element;W}{\mathrm{\&Sigma;}}\frac{{\mathrm{\&beta;}}_{\mathrm{ij}}}{K_{\mathrm{ij}}}$

(3) be target function with net damage and the peaked weighted sum of the out-of-limit probability of node voltage; With power flow equation constraint, the constraint of node voltage range of operation; The range constraint of exerting oneself that reactive power source is idle, the idle range constraint of transferring the files of exerting oneself constraint and transformer of reactive-load compensation equipment are that constraints is built and contained wind energy turbine set idle work optimization model based on the out-of-limit probability of voltage.

The wind energy turbine set reactive power optimization model that contains based on the out-of-limit probability of voltage comprises target function constraints two parts.

The target function that contains wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage does

$\min f={\mathrm{\&omega;}}_1{P}_L+{\mathrm{\&omega;}}_2\underset{i\&Element;N}{\mathrm{Max}}{\mathrm{\&beta;}}_i$

In the formula, P _LFor net decreases,

The maximum of the out-of-limit probability of all node overall situation voltages is found the solution in expression.ω ₁, ω ₂Be weight coefficient, span is 0 ~ 1, gets ω generally speaking ₁Be 0.2, ω ₂Be 0.8.Net decreases P _LComputational methods do

$P_L=\underset{i\&Element;N,j\&Element;N}{\mathrm{\&Sigma;}}{\left|\frac{V_i-V_j}{r_{\mathrm{oij}}+x_{\mathrm{Loij}}}\right|}^2\frac{r_{\mathrm{oij}}}{L_{\mathrm{ij}}}$

In the formula, V _iAnd V _jBe respectively the voltage of i node and j node.r _OijBe circuit unit resistance, the x between node i and the node j _LoijBe the circuit unit's reactance between node i and the node j, L _IjBe the line length between node i and the node j.

The constraints that contains wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage is power flow equation constraint, the constraint of node voltage allowed band; The generator reactive range constraint of exerting oneself, the range constraint of transferring the files of idle the exert oneself constraint and the transformer of reactive-load compensation equipment.

(4) adopt genetic algorithm for solving to contain wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage; Automatic voltage control system is controlled the action of reactive apparatus according to the control command of sending reactive apparatus based on the solving result that contains wind energy turbine set reactive power optimization model of the out-of-limit probability of voltage.Genetic algorithm is a kind of intelligent search algorithm of solving-optimizing model optimal solution commonly used.

Below being an example of calculation shows of the inventive method, is that example is carried out simulation calculation with domestic certain city A 110kV in 2011 and above upper strata electrical network.

Fig. 1 has reflected the idiographic flow that contains the wind energy turbine set reactive power optimization based on the out-of-limit probability of voltage.The practical implementation step is following:

1) the operation of power networks parameter of collection city A electrical network, the force data of gaining merit of the long-time section of the blower foundation parameter of wind energy turbine set Y and wind energy turbine set Y.

2), obtain local voltage factor of influence K through operation of power networks calculation of parameter electric network swim _Ij, and then obtain overall voltage influence factor K _iThe power conversion coefficient C of the blower foundation calculation of parameter blower fan through wind energy turbine set Y _pAsk for the parameter of the meritorious probability distribution equation of wind energy turbine set Y through gain merit force data and the least square fitting of wind energy turbine set Y;

3) be target function with net damage and the peaked weighted sum of the out-of-limit probability of node voltage; With power flow equation constraint, the constraint of node voltage range of operation; The range constraint of exerting oneself that reactive power source is idle, the idle range constraint of transferring the files of exerting oneself constraint and transformer of reactive-load compensation equipment are that constraints is built and contained wind energy turbine set idle work optimization model based on the out-of-limit probability of voltage.

4) adopt genetic algorithm for solving to contain wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage; Automatic voltage control system is controlled the action of reactive apparatus according to the control command of sending reactive apparatus based on the solving result that contains wind energy turbine set reactive power optimization model of the out-of-limit probability of voltage.

Fig. 2 has shown the power network topology of city A, only comprises a wind energy turbine set Y in the electrical network.The operation of power networks parameter is mainly gathered big mode operational factor in its summer.Because number of parameters is huge, within the rulely go out.

By the wind energy turbine set Y protocol requirement that is incorporated into the power networks, wind energy turbine set Y is with the power factor operation of constant hysteresis 0.95.Calculate through twice trend, calculate the voltage influence factor of city each node of A electrical network.

The blower foundation parameter of the wind energy turbine set Y that collects does

Table 1 MY1.5s fan parameter

Getting atmospheric density is under the atmospheric pressure, the atmospheric density in the time of 20 degrees centigrade, i.e. 1.205kg/m3.Calculating can get, C _pBe about 0.4912.

Fig. 3 has shown the wind energy turbine set Y2011 110 days force data of gaining merit of totally 31304 sampled points (5 minutes sampled points).

Fig. 4 has shown the result who adopts meritorious probability distribution equation of wind energy turbine set and least square fitting.Among the figure, dotted line is wind energy turbine set Y gain merit the actual probability distribution of force data, and solid line then is a fitting result.Fitting result: dimensional parameters c is 10.818, and form parameter k is 2.842.

Weight coefficient ω ₁, ω ₂Get 0.2,0.8 respectively.Then the target function based on the idle work optimization model that contains wind energy turbine set city A electrical network of the out-of-limit probability of voltage does

$\min f=0.2P_L+0.8\underset{i\&Element;N}{\mathrm{Max}}{\mathrm{\&beta;}}_i$

In the formula, P _LFor A net in city decreases,

The maximum of the out-of-limit probability of all node overall situation voltages of city A electrical network is found the solution in expression.Simultaneously, this model is with power flow equation constraint, the constraint of node voltage range of operation, the range constraint of exerting oneself that reactive power source is idle, and the idle range constraint of transferring the files of exerting oneself constraint and transformer of reactive-load compensation equipment is a constraints.

Fig. 5 a and Fig. 5 b have shown before the optimal control respectively and the voltage of the 110kV electrical network after the optimal control distributes.The node voltage of 100kV electrical network allows the upper limit and node voltage to allow lower limit to be respectively 106.7kV and 117.7kV.It is thus clear that through after the idle work optimization, there do not have voltage to occur to be out-of-limit, idle work optimization has guaranteed quality of voltage well.

The contrast of other two association does

Table 2 result contrast

Visible by table 2, Y net in city decreases 3.85% (being 1.05MW) that descended, and can be the remaining a lot of costs of operation of power networks.Simultaneously, the out-of-limit probability mean value of overall voltage has descended 99.15%, explains that Optimization result more can adapt to the fluctuation and the intermittence of wind energy turbine set power.

Fig. 6 a and Fig. 6 b shown successively before the Y optimal control of city with optimal control after the overall voltage out-of-limit probability of all 110kV nodes.Thus it is clear that, before the optimization, have quite a few node voltage out-of-limit (the out-of-limit probability of overall voltage of node is greater than 1) to occur; And optimize fluctuation and intermittent influence the (the out-of-limit probability of overall voltage of node is greater than 0) that the nearly all 110kV node in back does not receive wind energy turbine set power fully, only there is 1 110kV node wind-engaging film to ring.

Can prove by above execution mode example; Containing wind energy turbine set reactive power optimization method and not only can when guaranteeing quality of voltage, reduce grid net loss based on the out-of-limit probability of voltage; Reduce the operation of power networks cost, can also improve fluctuation and the intermittent adaptability of grid nodes voltage wind energy turbine set power.

Claims (6)

1. One kind based on the out-of-limit probability of voltage contain wind energy turbine set reactive power optimization method, it is characterized in that may further comprise the steps:

   (1) force data of gaining merit of the blower foundation parameter of collection operation of power networks parameter, each wind energy turbine set and the long-time section of wind energy turbine set; The operation of power networks parameter comprises: power network topology, line parameter circuit value, transformer station's parameter, load parameter, generator parameter, node voltage allow range of operation, reactive-load compensation equipment parameter, node serial number set N and wind energy turbine set numbering set W; Power network topology refers to the connected mode of circuit and circuit, circuit and transformer in the electrical network, and the line parameter circuit value of each bar circuit comprises circuit unit resistance r _o, the reactance x of circuit unit _Lo, the susceptance X of circuit unit _CoWith line length L; Transformer station's parameter comprises the transformer number n _T, the equivalent resistance r of each transformer _T, equivalent reactance x _T, transformer equivalent no-load voltage ratio k _T, no-load voltage ratio upper limit k _MaxWith no-load voltage ratio lower limit k _MinThe load parameter of each node includes workload P _LNWith load or burden without work Q _LNGenerator parameter comprises as the active power of traditional power plant of PV node and voltage, as the active power of traditional power plant of PQ node and reactive power and as the voltage and the phase angle of traditional power plant of V θ node; The node voltage allowed band comprises that node voltage allows upper limit V _MaxAllow lower limit V with node voltage _MinThe reactive-load compensation equipment parameter comprises that the capacitor group of each node counts n _CWith every pool-size n _Co, each node the reactor group count n _LWith every pool-size n _LoThe underlying parameter of each wind electric field blower comprises the rated power P of blower fan _N, incision wind speed v _In, cut-out wind speed v _Out, rated wind speed v _NWith wind sweeping area A;

   (2) through operation of power networks calculation of parameter electric network swim, obtain the voltage influence factor, i.e. local voltage factor of influence K _IjWith overall voltage influence factor K _iCalculate the power conversion coefficient C of blower fan through the underlying parameter of blower fan _pObtain the dimensional parameters c and the form parameter k of the meritorious probability distribution equation of wind energy turbine set through gain merit force data and the least square fitting of wind energy turbine set; Local voltage factor of influence K _IjWith overall voltage influence factor K _i, blower fan power conversion coefficient C _pBe used for the out-of-limit probability of computing node voltage with meritorious probability distribution equation;

   (3) decrease with net and the peaked weighted sum of the out-of-limit probability of node voltage is a target function, with power flow equation, node voltage range of operation, reactive power source is idle exerts oneself that scope, reactive-load compensation equipment idle exerted oneself and the scope of transferring the files of transformer is that constraints is built and contained wind energy turbine set idle work optimization model based on the out-of-limit probability of voltage;

   (4) adopt genetic algorithm for solving to contain wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage; Automatic voltage control system is controlled the action of reactive apparatus according to the control command of sending reactive apparatus based on the solving result that contains wind energy turbine set reactive power optimization model of the out-of-limit probability of voltage.
2. 2. according to claim 1ly contain wind energy turbine set reactive power optimization method based on the out-of-limit probability of voltage; It is characterized in that: the said voltage influence factor refers to the influence degree of wind energy turbine set to a certain grid nodes voltage, and the voltage influence factor is divided two kinds: i.e. local voltage factor of influence K _IjWith overall voltage influence factor K _i, both relations do

   $K_i=n_W/\left(\underset{j\&Element;W}{\mathrm{\&Sigma;}}\frac{1}{K_{\mathrm{ij}}}\right)---\left(1\right)$

   Local voltage factor of influence K _IjBe wind energy turbine set j, j is the element of wind energy turbine set numbering set W, and effect down separately; Cause the per unit node i, i is the element of node serial number set N, the active power variable quantity of the wind energy turbine set j that voltage variety is required; Each wind energy turbine set is carried out twice trend calculate, the operation of power networks parameter of twice trend calculating remains unchanged, and calculates wind energy turbine set zero for the first time and sends out; Calculate for the second time that wind energy turbine set is completely sent out and with given hysteresis firm power factor φ operation, then local voltage factor of influence K _IjComputational methods do

   $K_{\mathrm{ij}}=\frac{P_{\mathrm{jN}}}{\mathrm{\&Delta;}{V}_{\mathrm{ijMax}}}---\left(2\right)$

   In the formula, P _JNInstalled capacity for wind energy turbine set j; Δ V _IjMaxBe the voltage variety of twice trend calculating of node i,

   Overall situation voltage influence factor K _iReferring in all wind energy turbine set influences down simultaneously, causes total active power variable quantity of all wind energy turbine set that per unit node i voltage variety is required.
3. 3. according to claim 1 based on the out-of-limit probability of voltage contain wind energy turbine set reactive power optimization method, it is characterized in that: said power conversion coefficient C _pRefer to the ratio of blower fan electromagnetic power and wind wheel mechanical output, obtain by the following formula estimation,

   $C_p=\frac{2P_N}{\mathrm{\&rho;A}{v}_N^3}---\left(3\right).$
4. 4. according to claim 1 based on the out-of-limit probability of voltage contain wind energy turbine set reactive power optimization method, it is characterized in that: the meritorious probability distribution equation of said wind energy turbine set does

   $\mathrm{\&beta;}\left(P\right)=\left\{\begin{array}{cc}1-\exp [-{\left(\frac{v_{\mathrm{in}}}{c}\right)}^k]+\exp [-{\left(\frac{v_{\mathrm{out}}}{c}\right)}^k]& (0\&le;P<P_1)\\ 1-\exp [-{\left(\frac{v_p}{c}\right)}^k]+\exp [-{\left(\frac{v_{\mathrm{out}}}{c}\right)}^k]& (P_1\&le;P<P_N)\\ 1& (P=P_N)\end{array}\right.---\left(4\right)$

   In the formula, P is that the meritorious of blower fan exerted oneself; P ₁For wind speed is v _InThe meritorious of Shi Fengji exerted oneself; v _pFor exerting oneself P less than rated power and greater than P when blower fan is meritorious ₁The meritorious P corresponding air speed of exerting oneself of Shi Fengji, v _pComputational methods do

   $v_p=\sqrt[3]{\frac{2P}{C_P\mathrm{A\&rho;}}}---\left(5\right)$

   In the formula, C _pBe the wind energy conversion efficiency, ρ is the atmospheric density at wind wheel hub height place, and A is the wind wheel wind sweeping area.
5. 5. according to claim 1ly contain wind energy turbine set reactive power optimization method based on the out-of-limit probability of voltage; It is characterized in that: the out-of-limit probability of said voltage refers under the steady state condition; In a control cycle of automatic voltage control system; Out-of-limit probability takes place in the node voltage of electrical network wind-engaging influence, and the out-of-limit probability of voltage divides two kinds: the out-of-limit probability β of local voltage _IjWith the out-of-limit probability β of overall voltage _i

   The out-of-limit probability β of local voltage _IjRefer to when node i is influenced separately by wind energy turbine set j the out-of-limit probability of voltage takes place, establish node i voltage and allow intermediate value V _i ⁰Be the intermediate value of node voltage permission range of operation, promptly

   ${V_i}^0=\frac{1}{2}(V_{\mathrm{iMin}}+V_{i\max })---\left(6\right)$

   In the formula, V _ImaxNode i voltage allows the upper limit and V _IminNode i voltage allows lower limit;

   When node i voltage allows upper limit V _IMaxVoltage variety Δ V with twice trend calculating of node i _IjMaxAbsolute difference allow intermediate value V greater than node i voltage _i ⁰The time, the out-of-limit probability β of local voltage _IjFor

   

   In the formula, n _jBe wind energy turbine set j blower fan number,

   

   Referring to will

   

   Substitution (4) in P calculate,

   

   Referring to will

   

   P in the substitution (4) calculates;

   When node i voltage allows upper limit V _IMaxVoltage variety Δ V with twice trend calculating of node i _IjMaxAbsolute difference allow intermediate value V less than node i voltage _i ⁰The time, the out-of-limit probability β of local voltage _IjFor

   

   In the formula;

   

   refers to the P in the substitution (4) of

   

   calculated,

   

   refer to the P in

   

   substitution (4) calculated;

   Therefore, the out-of-limit probability β of the overall voltage of node i _iFor

   ${\mathrm{\&beta;}}_i=\frac{K_i}{n_W}\underset{j\&Element;W}{\mathrm{\&Sigma;}}\frac{{\mathrm{\&beta;}}_{\mathrm{ij}}}{K_{\mathrm{ij}}}---\left(9\right).$
6. 6. according to claim 1 based on the out-of-limit probability of voltage contain wind energy turbine set reactive power optimization method, it is characterized in that: the said wind energy turbine set reactive power optimization model that contains based on the out-of-limit probability of voltage comprises target function constraints two parts,

   The target function that contains wind energy turbine set reactive power optimization model based on the out-of-limit probability of voltage does

   $\min f={\mathrm{\&omega;}}_1{P}_L+{\mathrm{\&omega;}}_2\underset{i\&Element;N}{\mathrm{Max}}{\mathrm{\&beta;}}_i---\left(10\right)$

   Wherein, P _LFor net decreases;

   

   The maximum of the out-of-limit probability of all node overall situation voltages is found the solution in expression; ω ₁, ω ₂Be weight coefficient, span is 0 ~ 1, and net decreases P _LComputational methods do

   $P_L=\underset{i\&Element;N,j\&Element;N}{\mathrm{\&Sigma;}}{\left|\frac{V_i-V_j}{r_{\mathrm{oij}}+x_{\mathrm{Loij}}}\right|}^2\frac{r_{\mathrm{oij}}}{L_{\mathrm{ij}}}---\left(11\right),$

   In the formula, V _iAnd V _jBe respectively the voltage of i node and j node; r _OijBe circuit unit resistance, the x between node i and the node j _LoijBe the circuit unit's reactance between node i and the node j, L _IjBe the line length between node i and the node j.

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