CN101949363A - Method for grouping wind generating sets by taking input wind speed and random fluctuation of wind direction of wind farm into consideration - Google Patents

Abstract

The invention discloses a method for grouping wind generating sets, which takes the input wind speed and the random fluctuation of wind direction of a wind farm into consideration as well as wake effect among the wind generating sets, and then provides the method for grouping the wind generating sets by using the correlation coefficients of the wind generating sets. The technical scheme of the method is as follows: considering the wake effects among the wind generating sets and then determining the input wind speeds of the wind generating sets; studying the influence of wind direction change on the input wind speed of the wind generating set; calculating the correlation coefficients of the wind generating sets in each wind speed and wind direction intervals of the wind farm so as to obtain a three-dimensional correlation coefficient matrix; and in each wind speed interval under a same wind direction, arranging the wind generating sets with the same correlation coefficients into a group so as to complete the process of grouping the wind generating sets. The method overcomes the influences of the actions (grouping the wind generating sets without considering the influences of the wind speed and wind direction changes and the wake effects between the wind generating sets or only according to one of the factors above) on wind generating set grouping; and by using the method of the invention, the grouping situation of the wind generating sets can be inquired easily when the wind speed and the wind direction change, and the equivalent input wind speed of each wind generating set can be calculated so as to build a stochastic model of the wind farm and then determine the output power of the wind farm; the output characteristics of the wind farm connected to the grid and the influence on the operation characteristics of the grid are studied, and accurate wind power data can be provided for the electric network management departments.

Description

Take into account the wind-powered electricity generation unit group technology of wind energy turbine set input wind speed and direction random fluctuation

Technical field

The present invention relates to a kind of wind-powered electricity generation unit group technology, particularly a kind of wind-powered electricity generation unit group technology of considering wake effect between wind energy turbine set input wind speed, wind direction random fluctuation and wind-powered electricity generation unit is used for the modeling of large-scale wind electricity field and the analysis of being incorporated into the power networks.

Background technique

Along with the fast development of China recent years wind-power electricity generation, carry out research and assessment that wind energy turbine set inserts electric power system, carrying out system and key node, to admit the wind-powered electricity generation Research on ability be the major issue that presses for solution in the current wind-powered electricity generation development.From the angle of electric power system, what wind energy turbine set was carried out that research institute is concerned about is not that the characteristic of the inner every typhoon group of motors of wind energy turbine set but wind energy turbine set are made as a whole dynamic characteristic and to the influence of electric power system.Need set up when therefore, wind energy turbine set inserts Power System Analysis to satisfy and analyze the dynamic model that requires.

Wind energy turbine set is different from conventional power station, and wind energy turbine set is made up of the wind-powered electricity generation machine group of a large amount of dispersed placement.Because the wind wheel of upstream wind-powered electricity generation unit blocks downstream wind-powered electricity generation unit wind wheel, the input wind speed of downstream wind-powered electricity generation unit just is lower than the input wind speed of upstream wind-powered electricity generation unit, and the wind-powered electricity generation unit is at a distance of near more, and the influence between them is big more.The large-scale wind electricity field is made up of tens even hundreds of typhoon group of motors usually, and in order to make full use of land resources, these wind-powered electricity generation units can not be at a distance of too far away.In the wind energy turbine set input wind speed of every typhoon group of motors except all along with wind energy turbine set the wind comes from the wind speed and the wind direction of the wind comes from fluctuation and fluctuating, wake effect between the wind-powered electricity generation unit also may make the wind-powered electricity generation unit input wind speed of different infields have notable difference, causes the running state of wind-powered electricity generation unit in the synchronization wind energy turbine set incomplete same.Therefore, under setting up the fluctuations in wind speed situation during dynamic model of grid connected wind power field, should at first consider the influence of wake effect between the random fluctuation of wind energy turbine set input wind speed and direction and wind-powered electricity generation unit, runnability according to the wind-powered electricity generation unit is divided into groups to the wind-powered electricity generation unit, and then sets up the wind energy turbine set Equivalent Model.

At present, existing wind-powered electricity generation unit group technology has:

(1) all wind-powered electricity generation units in the wind energy turbine set is classified as one group.It in two kinds of situation, the one, do not consider the wake effect between the wind-powered electricity generation unit, think that the input wind speed of all wind-powered electricity generation units is all identical in the wind energy turbine set, they are classified as one group and equivalence become a typhoon group of motors, set up the wind energy turbine set Equivalent Model then; The 2nd, the input wind speed difference of consideration wind-powered electricity generation unit, but still the different wind-powered electricity generation unit of input wind speed is classified as one group, in wind-powered electricity generation unit equivalent process, wind energy conversion system is different with the generator processing method, just the generator to the wind-powered electricity generation unit carries out equivalence, and not to the wind energy conversion system equivalence, like this being classified as one group the equivalent equivalent generator of one-tenth of wind-powered electricity generation unit and the combination of many wind energy conversion systems.

(2) be linked to that all wind-powered electricity generation units all are classified as one group on same the current collection circuit, and their equivalences are become a typhoon group of motors.

(3) for the wind energy turbine set of wind-powered electricity generation unit arranged rule, divide into groups according to wind-powered electricity generation unit mounting point.As marine wind electric field, suppose identically with the wind energy turbine set vertical every motor exhaust group input wind speed of wind direction of the wind comes from, every motor exhaust group is classified as one group and equivalence becomes an equivalent wind-powered electricity generation unit.

(4) when wind-powered electricity generation unit arranged is irregular, the double-fed fan motor unit is divided into groups according to the characteristic root of the mechanical transient mathematical model of generator.

(5) utilize the power coherence in the power system dynamic equivalence method to determine that the wind-powered electricity generation unit in the wind energy turbine set divides into groups, use relevant equivalent method pattern wind energy turbine set is carried out equivalence.

In sum, when the wind-powered electricity generation unit is divided into groups, do not consider that wake effect is to the influence of wind-powered electricity generation unit grouping between wind energy turbine set input wind speed and direction change at random and wind-powered electricity generation unit.Wake effect directly influences the input wind speed of every typhoon group of motors between wind energy turbine set input wind speed, wind direction and wind-powered electricity generation unit, and changes with the random fluctuation of wind speed and direction, so the grouping of wind-powered electricity generation unit also should be a change at random in the wind energy turbine set.Therefore, the operation conditions of taking into account the wind-powered electricity generation unit rationally to the wind-powered electricity generation unit grouping to set up the wind energy turbine set dynamic model be very necessary and have practical significance.

Summary of the invention

The objective of the invention is to consider wake effect between the random fluctuation of wind energy turbine set input wind speed, wind direction and wind-powered electricity generation unit to the grouping of wind-powered electricity generation unit influence, give chapter and verse 3 dimension correlation matrixs to the method that the wind-powered electricity generation unit divides into groups, provide the method for calculating wind-powered electricity generation unit correlation coefficient and the method for utilizing every group of wind-powered electricity generation unit equivalence of this coefficient calculations input wind speed.Utilize the method can set up the stochastic model of wind energy turbine set, wind energy turbine set output characteristics during the random fluctuation of research wind energy turbine set input wind speed and direction.

The present invention for achieving the above object, the technological scheme of employing is:

1. wind-powered electricity generation unit input wind speed determines

Wind can be represented with N.O.Jensen wake model as shown in Figure 1 by the approach of upstream wind wheel propagates down stream.Fig. 1 apoplexy group of motors is installed in 0 place, and x is along the distance of leaving the wind-powered electricity generation unit through the wind direction behind the wind wheel; r _RotIt is the wind wheel radius; A _RotBe the area that wind wheel scanned; α is the conical tip factor; R (x) is the projection radius of wind wheel at x place conical surface, also is the wake flow radius of wind wheel at the x place:

r(x)＝r _rot+tanα·x (1)

In the formula: tan α=k is the wake flow decay constant, its expression wind through behind wind wheel when being directed downwards of rotor shaft propagated, the length that 1 meter wind wheel projection plane of every propagation radius increases can be provided by following empirical correlation:

$k=\frac{0.5}{\ln \left(\frac{Z}{r_e}\right)}---\left(2\right)$

In the formula: Z is a horizontal fan axle center height; r _eBe roughness of ground surface.According to the wind energy turbine set topography and landform character, the value of k is as shown in table 1.

The value of table 1 wake flow decay constant

Classification of landform	Wake flow decay constant k	Topograph
			The sea level	0.04	Lake surface, sea
Mix on water and land	0.052	Mix on the water surface and land, also is suitable for very level and smooth landform
			Very open grassland	0.063	There are not the fence that intersects, the building of dispersion, level and smooth mountain
Open grassland	0.075	8 meters high buildings and obstacle are arranged beyond 1250 meters
			The grassland that building is arranged	0.083	8 meters high buildings and obstacle are arranged beyond 800 meters
Trees and grassland	0.092	The vegetation that 8 meters high buildings and obstacle, level of confidentiality are arranged beyond 250 meters

Forest and village	0.1	Village, small town
			Large town	0.108	Large town
The big city	0.117	The big city

After considering the wake effect of 0 place's wind-powered electricity generation unit, at the input wind speed v of x place wind wheel _w(x) be:

$v_w\left(x\right)=v_0[1-{\left(\frac{r_{\mathrm{rot}}}{\mathrm{kx}+r_{\mathrm{rot}}}\right)}^2(1-\sqrt{1-C_T})]---\left(3\right)$

In the formula: C _TBe thrust coefficient.According to the feature of wind wheel input wind speed, general k has two kinds of values: as for marine wind electric field, when wind wheel input wind speed is that k does not equal 0.04 when being subjected to the wind speed of upstream wind energy conversion system wake effect, otherwise k equals 0.08.

Be installed in the area (A that x place wind mill wind wheel is scanned _Rot) degree of being blocked by its upstream wind wheel projection conical surface A (x) can become following situation by approximate representation: block fully, quasi-full is blocked, partial occlusion and not blocking.For partial occlusion, can represent two kinds of situations as Fig. 2 (a) and (b) according to the difference of area of overlap.

The area of overlap A of wind wheel among Fig. 2 (a) _ShadFor:

$A_{\mathrm{shad}}=A_1+A_2=r^2\left(x\right)\&CenterDot;{\cos }^{-1}({\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000290326900011.png,HSA00000290326900021.png"\; state="\{\{state\}\}">d</figure-callout>}}_1/r\left(x\right))+{\mathrm{<figure-callout\; id="2"\; label="r\; rot"\; filenames="HSA00000290326900022.png,HSA00000290326900032.png"\; state="\{\{state\}\}">r</figure-callout>}}_{\mathrm{rot}}^{}\&CenterDot;{\cos }^{-1}((d-d_1)/r_{\mathrm{rot}})-d\&CenterDot;Z---\left(4\right)$

The area of overlap A of wind wheel among Fig. 2 (b) _ShadFor:

$A_{\mathrm{shad}}={\mathrm{<figure-callout\; id="1"\; label="A"\; filenames="HSA00000290326900011.png,HSA00000290326900021.png"\; state="\{\{state\}\}">A</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="A"\; filenames="HSA00000290326900022.png,HSA00000290326900032.png"\; state="\{\{state\}\}">A</figure-callout>}}_2$

$=r^2\left(x\right){\cos }^{-1}\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HSA00000290326900022.png,HSA00000290326900032.png"\; state="\{\{state\}\}">d</figure-callout>}}^2+r^2\left(x\right)-r_{\mathrm{rot}}^2}{2d\&CenterDot;r\left(x\right)}\right)+r_{\mathrm{rot}}^2{\cos }^{-1}\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HSA00000290326900022.png,HSA00000290326900032.png"\; state="\{\{state\}\}">d</figure-callout>}}^2+r_{\mathrm{rot}}^2-r^2\left(x\right)}{2d\&CenterDot;r_{\mathrm{rot}}}\right)-d\&CenterDot;Z---\left(5\right)$

Because the wind wheel of arbitrary wind-power machine all might blocked by its upstream wind mill wind wheel in varying degrees in the wind energy turbine set, therefore in calculating wind energy turbine set, arbitrarily during the input wind speed of typhoon wheel, must consider that all the other wind energy conversion systems are to its influence in the wind energy turbine set.Momentum conservation law according to air-flow in the unit time draws the wind speed v that acts on any typhoon wheel _i(t):

$v_i\left(t\right)=\sqrt{v_{i0}^2\left(t\right)+\underset{k\&NotEqual;i}{\overset{n}{\underset{k=1}{\mathrm{\&Sigma;}}}}{\mathrm{\&beta;}}_k\&CenterDot;(v_{w0-\mathrm{ki}}^2\left(t\right)-v_{i0}^2\left(t\right))}---\left(6\right)$

In the formula: v _W0-ki(t) k platform wind energy conversion system acts on speed on the i platform wind energy conversion system when considering wake effect between the wind-powered electricity generation unit; v _I0(t) be the input wind speed on the i platform wind energy conversion system when not considering the wind wheel eclipse effect;

Be illustrated in i platform wind energy conversion system place, the ratio of the area of contour of k typhoon wheel and i typhoon wheel wind sweeping area; N is total platform number of wind energy conversion system.

2. wind direction changes the influence to wake effect between the wind-powered electricity generation unit

The yaw device of wind-powered electricity generation unit will make wind wheel aim at the direction of the wind comes from according to the recording anemometer and the wind vane of hub height when wind direction changes, and the wake effect zone of wind-powered electricity generation unit is box haul and becoming also, and influencing each other between the wind-powered electricity generation unit of upstream and downstream also will change.

Below with two typhoon group of motors WT as shown in Figure 3 _iAnd WT _kFor example is analyzed the influence of wind direction to wake effect between the wind-powered electricity generation unit.WT _iAnd WT _kPosition coordinate be respectively (x _i, y _i) and (x _k, y _k), two typhoon motor group distance d _IkFor:

$d_{\mathrm{ik}}=\sqrt{{(x_i-x_k)}^2+{(y_i-y_k)}^2}---\left(7\right)$

Wind direction is γ ₁The time, upstream blower fan WT _iAt downstream blower fan WT _kThe wake flow radius at place

For:

$r_{{\mathrm{\&gamma;}}_1}\left(x\right)=r_{\mathrm{rot}}+k*x=r_{\mathrm{rot}}+k*d_{\mathrm{ik}}=r_{\mathrm{rot}}+k*\sqrt{{(x_i-x_k)}^2+{(y_i-y_k)}^2}---\left(8\right)$

When wind direction is γ ₂The time, because the effect of wind energy conversion system device for regulating direction, the wind energy conversion system of normal operation makes wind wheel aim at wind direction always, causes upstream wind energy conversion system WT _iAlong wind direction γ ₂At downstream wind energy conversion system WT _kThe wake flow radius at place For:

$r_{{\mathrm{\&gamma;}}_2}\left(x\right)=r_{\mathrm{rot}}+k*\sqrt{{(x_i-x_k)}^2+{(y_i-y_k)}^2}*\cos \mathrm{\&alpha;}---\left(9\right)$

Comparison type (8) and (9) are to find out, wind direction is by γ ₁Become γ ₂The Shi Shangyou wind energy conversion system reduces at the wake flow radius at downstream wind energy conversion system place,

Substitution formula (4) and (5) can get, and wind direction is by γ ₁Become γ ₂The area of overlap of back upstream and downstream wind wheel also will reduce.Therefore, when wind direction changes, influencing each other between the wind-powered electricity generation unit of upstream and downstream also will change.It can also be seen that from formula (8) and (9), for wind-powered electricity generation machine set type and all fixed wind energy turbine set of location arrangements, after the input wind direction was determined, the upstream wind energy conversion system was also determined the screening area of downstream wind energy conversion system in the wind energy turbine set, and it has nothing to do with the input wind speed of wind-powered electricity generation unit.

3. utilize the method for wind-powered electricity generation unit correlation coefficient to the grouping of wind-powered electricity generation unit

The computing block diagram of the correlation coefficient of wind-powered electricity generation unit as shown in Figure 4.By the calculating to each wind speed and direction windward group of motors correlation coefficient of wind energy turbine set can obtain as shown in Figure 53 the dimension correlation matrixs.3 maintain the line display wind direction of matrix number, and its line number depends on the interval of selected wind direction; Matrix column is corresponding to the platform number of wind-powered electricity generation unit; The 3rd axle of matrix of the coefficients is corresponding to the input wind speed of wind energy turbine set, and its columns depends on the interval of selected wind speed; Each Elements C I is the correlation coefficient of wind-powered electricity generation unit in the matrix of the coefficients.

By calculating:

(1) each wind speed at interval in, if the identical wind-powered electricity generation unit of correlation coefficient is classified as one group, be identical in the grouping situation of same wind direction leeward group of motors.

(2) although the grouping of the at interval interior wind-powered electricity generation unit of each wind speed is identical under the same wind direction, the correlation coefficient of the at interval interior same group of wind-powered electricity generation unit of different wind speed is different.

By the correlation coefficient computational methods as can be seen, the correlation coefficient of every group of wind-powered electricity generation unit is except outside the Pass having with wind energy turbine set input wind speed, wind direction, and is also relevant with selected step-length and iterations.Under the situation of known wind energy turbine set input wind speed and direction, utilize wind-powered electricity generation unit correlation coefficient can calculate the input wind speed of every typhoon group of motors, wind speed v is imported in the equivalence that further draws every group of wind-powered electricity generation unit _Ei:

$v_{\mathrm{ei}}=v_{\inf }-{\mathrm{CI}}_i\&times;v_{\mathrm{step}}+\frac{v_{\mathrm{<figure-callout\; id="2"\; label="step"\; filenames="HSA00000290326900022.png,HSA00000290326900032.png"\; state="\{\{state\}\}">step</figure-callout>}}}{2}\mathrm{sgn}({\mathrm{CI}}_i-1)+v_{\mathrm{step}}\mathrm{NOT}\left\{\mathrm{sgn}({\mathrm{CI}}_i-1)\right\}---\left(10\right)$

In the formula: v _EiIt is i group wind-powered electricity generation unit equivalent wind speed; v _InfBe wind energy turbine set input wind speed; v _StepBe the wind speed step-length; CI _iIt is the correlation coefficient of i group wind-powered electricity generation unit; Sgn () is a sign function; NOT () is non-function.

For the wind energy turbine set of determining, can calculate the correlation coefficient of the at interval interior wind-powered electricity generation unit of each wind speed and direction by above-mentioned way.When wind energy turbine set input wind speed and direction changes, can draw the wind-powered electricity generation unit grouping situation corresponding under each wind speed and direction and the correlation coefficient of every group of wind-powered electricity generation unit by inquiry, calculate the equivalence input wind speed of every group of wind-powered electricity generation unit then according to the input recording anemometer of wind energy turbine set, prepare for setting up the wind energy turbine set model.

Beneficial effect of the present invention is embodied in: the wind-powered electricity generation unit group technology of utilizing the present invention to propose, overcome do not consider to the wind comes from wind energy turbine set in the past wind speed, the wind direction of the wind comes from change and the wind-powered electricity generation unit between wake effect, or only according to the wherein a certain factor influence that grouping brings to the wind-powered electricity generation unit; Wind-powered electricity generation unit grouping situation when utilizing the method can conveniently inquire about the variation of wind energy turbine set input wind speed and direction, and wind speed is imported in the equivalence that calculates every group of wind-powered electricity generation unit, set up the stochastic model of wind energy turbine set, further the decision wind energy turbine set exerts oneself, the output characteristics of research grid connected wind power field and to the influence of operation of power networks characteristic provides wind-powered electricity generation data comparatively accurately for rationally the arrange production plan, minimizing system reserve capacity of dispatching of power netwoks department simultaneously.

The explanation of accompanying drawing table

Fig. 1 N.O.Jensen wake model;

Fig. 2 wind wheel partial occlusion schematic representation

When changing, simplifies Fig. 3 wind direction wake model influence area schematic representation;

Definite block diagram of correlation coefficient in Fig. 4 correlation matrix;

Fig. 5 describes 3 of the interior wind-powered electricity generation unit coherence of wind energy turbine set and maintains matrix number;

The arranged of wind-powered electricity generation unit in Fig. 6 wind energy turbine set;

Fig. 7 flow diagram;

The correlation coefficient of 16 typhoon group of motors in wind energy turbine set during Fig. 8 wind direction γ=45 °;

Specific embodiments

Utilize drawings and Examples that the present invention is further described below.The wind-powered electricity generation unit group technology of taking into account the random fluctuation of wind energy turbine set input wind speed and direction that the present invention proposes is used to solve and traditional all wind-powered electricity generation units in the wind energy turbine set is classified as one group or arrange the problem that grouping etc. can't be handled according to the wind-powered electricity generation unit.Specific embodiments is as follows:

1. wind energy turbine set is 1.5MW by 16 capacity double-fed speed change wind-powered electricity generation unit is formed, the arranged of wind-powered electricity generation unit as shown in Figure 6 in the wind energy turbine set, impeller diameter is 70m, hub height is 65m, in the wind energy turbine set in every motor exhaust group between the adjacent two typhoon group of motors apart from d=400m, between adjacent two motor exhaust groups apart from δ=400m.

2. utilize Matlab that wake effect and wind direction between consideration wind-powered electricity generation unit are influenced the wind speed model and carry out emulation, flow diagram as shown in Figure 7, when wind direction γ=45 a ° wind speed was respectively 8m/s, 10m/s, 15m/s, the input wind speed of every typhoon group of motors was as shown in table 2 in the wind energy turbine set.

3. wind direction γ=45 °, when wind speed was respectively 8m/s, 10m/s, 15m/s, the correlation coefficient of wind-powered electricity generation unit as shown in Figure 8 in the wind energy turbine set.

4. utilize wind-powered electricity generation unit correlation coefficient shown in Figure 8 that the wind-powered electricity generation unit that correlation coefficient in the wind energy turbine set equates is classified as one group, then 16 typhoon group of motors can be divided into 4 groups, and WT1～WT6, WT9 are one group, and WT7, WT8, WT10～WT12 are one group, WT13～WT15 is one group, and WT16 is one group.

The input wind speed of wind-powered electricity generation unit when table 2 wind direction γ=45 °, wind speed variation

Claims (6)

1. take into account the wind-powered electricity generation unit group technology of wind energy turbine set input wind speed and direction random fluctuation, it is characterized in that: considered that wake effect, wind-powered electricity generation unit arranged and wind direction are to the influence of wind-powered electricity generation unit wake effect between the wind-powered electricity generation unit; Consider the random fluctuation of wind energy turbine set input wind speed and direction, proposed to utilize the method for 3 dimension correlation matrixs the grouping of wind-powered electricity generation unit.

2. a kind of influence of considering wind direction to the grouping of wind-powered electricity generation unit according to claim 1, it is characterized in that: consider that the wind-powered electricity generation unit makes wind wheel rotate along with wind direction changes according to the recording anemometer and the wind vane of hub height, calculates the screening area of upstream and downstream wind-powered electricity generation unit.

3. to the method for wind-powered electricity generation unit grouping, it is characterized in that: the method that has proposed to calculate wind-powered electricity generation unit correlation coefficient under a kind of random fluctuation situation of considering wind energy turbine set input wind speed and direction according to claim 1.

4. under a kind of random fluctuation situation of considering wind energy turbine set input wind speed and direction according to claim 1 to the method for wind-powered electricity generation unit grouping, it is characterized in that: according to 3 dimension correlation matrixs of wind-powered electricity generation unit, the wind-powered electricity generation unit that proposes in each wind speed interval correlation coefficient to be equated under same wind direction is classified as one group group technology.

5. under a kind of random fluctuation situation of considering wind energy turbine set input wind speed and direction according to claim 1 to the method for wind-powered electricity generation unit grouping, it is characterized in that: proposed at known wind energy turbine set input wind speed, utilized the correlation coefficient of wind-powered electricity generation unit to calculate the method for the equivalence input wind speed of every group of wind-powered electricity generation unit.

6. under a kind of random fluctuation situation of considering wind energy turbine set input wind speed and direction according to claim 1 to the method for wind-powered electricity generation unit grouping, it is characterized in that: utilize 3 dimension correlation matrixs that the wind-powered electricity generation unit is divided into groups, can realize the wind-powered electricity generation unit being divided into groups, and prepare for setting up the wind energy turbine set stochastic model with the random fluctuation of wind energy turbine set input wind speed and direction.

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