CN104343628A - Variable pitch control method for wind turbine generator with dead-time compensation device - Google Patents

Abstract

The invention discloses a variable pitch control method for a wind turbine generator with a dead-time compensation device, and belongs to the field of control system of the wind turbine generator. The variable pitch control method comprises the following steps: establishing a mathematic model of the wind turbine generator, obtaining a mathematic expression between an expected value of a pitch angle outputted by a variable pitch controller and an actual value of a pitch angle outputted by a variable pitch executing mechanism, designing the dead-time compensation device of the variable pitch executing mechanism, obtaining the mathematic expression of a pitch angle compensation value, measuring the wind speed around the wind turbine and active power outputted by the wind driven generator, calculating the pitch angle expected value, respectively transferring the value to the variable pitch executing mechanism and the dead-time compensation device of the variable pitch executing mechanism, calculating the pitch angle actual value and the pitch angle compensation value and transferring the values to a phase modulator inside the wind turbine, and adjusting the wind turbine by the phase modulator inside the wind turbine. The method well eliminates the interference and influence of the dead zone of the variable pitch executing mechanism on the whole system during the operation process of the wind turbine generator, promotes the running state of the wind turbine generator, and ensures the stability in power output.

Description

A kind of Wind turbines variable pitch control method containing dead-zone compensator

Technical field

The invention belongs to control system of wind turbines field, be specifically related to a kind of Wind turbines variable pitch control method containing dead-zone compensator.

Background technique

Wind energy, as a kind of clean renewable energy sources, is more and more subject to the attention of countries in the world, and is developed fast.For the utilization of wind energy, be mainly fixed against Wind turbines to carry out transformation of energy.Control system of wind turbines is the core that unit normally runs, and its control technique is one of key technology of Wind turbines, and close with other part relations of Wind turbines, it controls accurately, perfect function will directly affect the safety and efficiency of whole unit.

Variable pitch control technology is widely used as a kind of main flow control technique of Wind turbines, but, the character such as due to wind energy, there is very strong randomness, intermittence and can not regulate and control, add feather actuator and there is dead band and other many uncertain factors, variable-pitch control system is made to have the features such as parametrical nonlinearity, parameter time varying, hysteresis quality, the particularly impact that brings of feather actuator dead band, make the regulating and controlling of pitch-variable system there is deviation, cause Wind turbines output power unstable.

Summary of the invention

For the deficiency that prior art exists, the invention provides a kind of Wind turbines variable pitch control method containing dead-zone compensator.

Technological scheme of the present invention:

Step 1: the mathematical model setting up Wind turbines, obtains the propeller pitch angle expected value β that Variable-pitch Controller exports _rthe mathematic(al) representation of the propeller pitch angle actual value β exported with feather actuator:

$\mathrm{\β}=\frac{1}{\mathrm{\τs}+1}{\mathrm{\β}}_r---\left(1\right)$

In formula: τ is time constant; S is complex frequency, is supplementing of Fourier transformation.

Obtain the mathematic(al) representation that wind power capability caught by wind turbine simultaneously:

$C_p(\mathrm{\λ},\mathrm{\β})=(0.44-0.0167\mathrm{\β})\sin \left[\frac{\mathrm{\π}(\mathrm{\λ}-2)}{15-0.3\mathrm{\β}}\right]-0.00184(\mathrm{\λ}-2)\mathrm{\β}---\left(2\right)$

In formula: C _p(λ, β) is power coefficient.

Step 2: according to the propeller pitch angle expected value β of the Variable-pitch Controller output that step 1 obtains _rthe mathematic(al) representation of the propeller pitch angle actual value β exported with feather actuator, the dead-zone compensator of design feather actuator, obtains propeller pitch angle offset Δ β _rmathematic(al) representation, carry out as follows:

Step 2.1: the mathematical model setting up feather actuator dead band;

The mathematical model in the feather actuator dead band used in the present invention is as follows:

$D^{\&prime;}\left(u\right)=\left\{\begin{array}{cc}{g}_r\left(u\right),& u\&GreaterEqual;b_r\\ 0,& b_l<u<b_r\\ g_l\left(u\right),& u\&le;b_l\end{array}\right.---\left(3\right)$

In formula: D ' (u) represents the function expression about feather actuator dead band; b _rfor leaving feather actuator deadband upper limit wind speed size, m/s; b _lfor entering feather actuator deadband lower limit wind speed size, m/s; U is the input in feather actuator dead band; g _ru () is for working as u>=b _rtime feather actuator Dead zone representation; g _lu () is for working as u≤b _ltime feather actuator Dead zone representation;

Step 2.2: to the estimation of nonlinear dynamic function f (x);

f(x)＝W ₁ ^*Tσ(V ₁ ^TX ₁)+ε ₁(4)

In formula: X ₁=[x ₁x ₂x _n1] ^t∈ R ⁿ⁺¹; V ₁for the weight matrix between first nerves network input layer and hidden layer; W ₁ ^*for the desirable weight matrix between first nerves network hidden layer and output layer; ε ₁for first nerves network reconfiguration error; σ is activation primitive, and concrete form is $\mathrm{\&sigma;}\left(z\right)={\left[\begin{array}{cc}\stackrel{\&OverBar;}{\mathrm{\&sigma;}}& 1\end{array}\right]}^T\&Element;R^{l+1};$

Consider threshold function, activation primitive of the present invention is elected as wherein, have in the present invention l is node in hidden layer, and the broad sense that z represents whole system exports; And the output of the first nerves network of reality is

$\hat{f}={W_1}^T\mathrm{\&sigma;}\left({V_1}^T{X}_1\right)---\left(5\right)$

In formula, W ₁for the actual weight matrix between first nerves network hidden layer and output layer; Then the network-evaluated error of first nerves can be expressed as

$\hat{f}-f\left(x\right)={{\tilde{W}}_1}^T\mathrm{\&sigma;}-{\mathrm{\&epsiv;}}_1---\left(6\right)$

In formula: for neural network weight evaluated error;

Step 2.3: the compensator in design feather actuator dead band, obtains propeller pitch angle offset Δ β _rmathematic(al) representation;

The output of nervus opticus network is utilized in design of Compensator offset system fading margin error η (u) caused by feather actuator dead band, wherein nervus opticus network is input as u _c;

Nervus opticus network is utilized to obtain propeller pitch angle offset Δ β _rgeneralized Mathematical representation be

In formula: W ₂for the actual weight matrix between nervus opticus network hidden layer and output layer; X ₂=[x ₁x ₂x _n1] ^t∈ R ⁿ⁺¹; V ₂for the weight matrix between nervus opticus network input layer and hidden layer; ε ₂for nervus opticus network reconfiguration error.

Step 3: utilize air velocity transducer to measure the wind speed v of wind turbine periphery, utilizes Hall voltage, current sensor to record the voltage and current of wind-driven generator output respectively, and both are multiplied and obtain the active-power P of wind-driven generator output.

Step 4: Variable-pitch Controller calculates propeller pitch angle expected value β _rand be sent to the dead-zone compensator of feather actuator and feather actuator respectively;

Step 5: feather actuator calculates propeller pitch angle actual value β and sends the interior phase modulation device of wind turbine to, meanwhile, the dead-zone compensator of feather actuator calculates propeller pitch angle offset Δ β _rand send the interior phase modulation device of wind turbine to;

Step 6: according to the pitch angle value received, i.e. propeller pitch angle actual value β and propeller pitch angle offset Δ β _r, the interior phase modulation device of wind turbine regulates wind turbine.

Beneficial effect:

There is dead band in feather actuator and Wind turbines is objective reality by its very large risk affected, therefore build a set of perfect variable pitch control method containing dead-zone compensator being exclusively used in Wind turbines and there is urgency and necessity.Variable pitch control method of the present invention solves following Problems existing:

(1) consider that the data volume in Wind turbines has the features such as ambiguity, randomness, uncertainty and redundancy, utilize variable pitch control method of the present invention, successfully overcome currently available technology and can only regard feather actuator dead band as perfect condition and the actual shortcoming solved cannot be gone;

(2) improve the overall performance of Wind turbines and the control accuracy of pitch-variable system, essentially eliminate feather actuator dead band to the impact of Wind turbines.Be specifically designed to the use of the variable pitch control method containing dead-zone compensator of Wind turbines, well solve in running of wind generating set, feather actuator dead band, on the interference of whole system and impact, can be good at the running state promoting Wind turbines, the stability that guaranteed output exports.

Accompanying drawing explanation

Fig. 1 is the Wind turbines variable pitch control structural representation of one embodiment of the present invention;

Fig. 2 is the dead zone area schematic diagram of the feather actuator of one embodiment of the present invention;

Fig. 3 is the Wind turbines variable pitch control method flow chart containing dead-zone compensator of one embodiment of the present invention;

Fig. 4 is the Wind turbines variable pitch control structural representation containing dead-zone compensator of one embodiment of the present invention;

Fig. 5 is the wind turbine rotating speed analogous diagram of one embodiment of the present invention;

Fig. 6 is the wind driven generator output power analogous diagram of one embodiment of the present invention.

Embodiment

By describing technology contents of the present invention in detail, being reached object and effect, be described in further detail below in conjunction with the drawings and the specific embodiments.

As shown in Figure 1, be a Wind turbines variable pitch control structural representation not adding dead-zone compensator, comprise wind turbine, transmission system, wind-driven generator and pitch-variable system, pitch-variable system comprises again Variable-pitch Controller and feather actuator.Wind turbine is the driving link of Wind turbines, for capturing wind energy; The wind energy that wind turbine is caught by transmission system passes to wind-driven generator; Wind-driven generator is through electromagnetic conversion, and active power of output, pitch-variable system is then by regulating the propeller pitch angle of wind turbine to regulate Wind energy extraction size, thus ensures that Wind turbines can export constant performance number, meets system requirements.Wherein, the active-power P that Variable-pitch Controller exports according to the wind-driven generator received and the wind speed v of wind turbine periphery, the propeller pitch angle expected value β utilizing the calculated with mathematical model of Wind turbines to go out to regulate _r, and this value is sent to feather actuator to perform.But actuator exists dead band due to feather, as shown in Figure 2, at wind speed v higher than rated wind speed v ₁be less than cut-out wind speed v ₂time, pitch-variable system is started working, the region 2 namely in accompanying drawing 2.In this section of region, due to feather there is dead band in actuator, when causing final feather actuator to perform send wind turbine to pitch angle value be not β _r, but producing the pitch angle value actual value β of certain deviation, namely feather actuator actual output pitch angle value, the departure size produced is β '=β _r-β.Owing to there is certain deviation, so cause the interior phase modulation device of wind turbine wind turbine not to be adjusted to the position that should regulate, thus have impact on the output of the active-power P of wind-driven generator.

Based on this, produce a propeller pitch angle offset Δ β by the dead-zone compensator of a design feather actuator in the present invention _roffset propeller pitch angle departure β ', make the pitch angle value being ultimately delivered to wind turbine interior phase modulation device reach propeller pitch angle expected value β as far as possible _r.

The Wind turbines variable pitch control method containing dead-zone compensator of present embodiment, as shown in Figure 3, comprises following concrete steps:

Step 1: the mathematical model setting up Wind turbines, obtains the propeller pitch angle expected value β that Variable-pitch Controller exports _rthe mathematic(al) representation of propeller pitch angle actual value β that exports of mathematic(al) representation, feather actuator;

Step 1.1: the mathematical model setting up wind turbine;

Wind turbine is the device of mechanical energy by wind energy transformation, and theoretical according to Bates, the power that wind turbine is caught from wind energy and machine torque are:

$P_r=\frac{1}{2}\mathrm{\&rho;\&pi;}{R}^2{v}^3{C}_p(\mathrm{\&lambda;},\mathrm{\&beta;})---\left(8\right)$

$T_r=\frac{1}{2}\mathrm{\&rho;\&pi;}{R}^2{v}^3{C}_T(\mathrm{\&lambda;},\mathrm{\&beta;})---\left(9\right)$

In formula: P _rfor the power that wind turbine is caught, w; T _rfor the machine torque of wind wheel, Nm; λ is tip speed ratio; ρ is the density of air, kg/m ³; R is the radius of wind wheel, m; V is wind speed, m/s; β is propeller pitch angle actual value, rad; C _t(λ, β) is machine torque coefficient; C _p(λ, β) is power coefficient;

C _t(λ, β) and C _pthe relation of (λ, β) can be showed by following representation:

C _p(λ，β)＝λC _T(λ，β) (10)

Power coefficient C _p(λ, β) represents the ability that wind power caught by wind turbine, and the present invention adopts following formula to be similar to:

$C_p(\mathrm{\&lambda;},\mathrm{\&beta;})=(0.44-0.167\mathrm{\&beta;})\sin \left[\frac{\mathrm{\&pi;}(\mathrm{\&lambda;}-2)}{15-0.3\mathrm{\&beta;}}\right]-0.00184(\mathrm{\&lambda;}-2)\mathrm{\&beta;}---\left(2\right)$

Step 1.2: the mathematical model setting up wind-driven generator;

According to the mathematical model of wind turbine, the wind energy size that wind turbine is caught can be drawn.Wind turbine as driving link by caught wind energy P _rsend transmission system to, wind energy transformation is that mechanical energy sends wind-driven generator to by transmission system again, and the torque that final transmission system sends wind-driven generator to is T _g, wind-driven generator is converted into required electric energy according to the mechanical energy sent by electromagnetic conversion again, and for the ease of calculating, the mathematical model of the wind-driven generator that present embodiment is set up is as follows:

$(J_r+V_i^2{J}_g){\stackrel{.}{\mathrm{\&omega;}}}_r=T_r-T_D-v_i{T}_e---\left(11\right)$

$T_D=C_1+\frac{C_2}{{\mathrm{\&omega;}}_r}+C_3{\mathrm{\&omega;}}_r---\left(12\right)$

In formula: J _rfor wind wheel rotary inertia, kgm ²; J _gfor wind-driven generator rotary inertia, kgm ²; ω _rfor wind turbine actual speed, r/min; v _ifor reduction speed ratio; T _efor wind-driven generator electromagnetic torque, Nm; T _dfor wind-driven generator resisting moment, Nm; C ₁, C ₂, C ₃for damping constant;

Step 1.3: the mathematical model setting up Variable-pitch Controller, obtains the propeller pitch angle expected value β that Variable-pitch Controller exports _rthe mathematic(al) representation of the propeller pitch angle actual value β exported with feather actuator;

By the wind turbine set up and the mathematical model of wind-driven generator, can draw wind energy that in present embodiment, wind turbine is caught and wind-driven generator change the electric energy of output.In accompanying drawing 2 region 2, need to regulate propeller pitch angle by pitch-variable system thus ensure that wind driven generator output power is constant.For pitch-variable system, comprise Variable-pitch Controller and feather actuator two-part, the present invention needs the mathematical model by setting up Variable-pitch Controller, obtains the propeller pitch angle expected value β that Variable-pitch Controller exports _rthe mathematic(al) representation of the propeller pitch angle actual value β exported with feather actuator.

The mathematical model of the Variable-pitch Controller that present embodiment is set up is as follows:

$\frac{1}{\mathrm{\&tau;}}\stackrel{.}{\mathrm{\&beta;}}={\mathrm{\&beta;}}_r-\mathrm{\&beta;}---\left(13\right)$

$T_D=C_1+\frac{C_2}{{\mathrm{\&omega;}}_r}+C_3{\mathrm{\&omega;}}_r---\left(14\right)$

In formula: τ is time constant; β _rfor propeller pitch angle expected value, rad;

The propeller pitch angle expected value β that the Variable-pitch Controller obtained exports _rthe mathematic(al) representation of propeller pitch angle actual value β that exports of mathematic(al) representation, feather actuator, be common relation, shown in (1):

$\mathrm{\&beta;}=\frac{1}{\mathrm{\&tau;s}+1}{\mathrm{\&beta;}}_r---\left(1\right)$

In formula: s is complex frequency, be supplementing of Fourier transformation.

Step 2: according to the result of step 1, the dead-zone compensator of design feather actuator, obtains propeller pitch angle offset Δ β _rmathematic(al) representation;

Step 2.1: the mathematical model setting up feather actuator dead band;

The mathematical model in the feather actuator dead band used in present embodiment is as follows:

$D^{\&prime;}\left(u\right)=\left\{\begin{array}{cc}{g}_r\left(u\right),& u\&GreaterEqual;b_r\\ 0,& b_l<u<b_r\\ g_l\left(u\right),& u\&le;b_l\end{array}\right.---\left(3\right)$

In formula: D ' (u) represents the function expression about feather actuator dead band; b _rfor leaving feather actuator deadband upper limit wind speed size, m/s; b _lfor entering feather actuator deadband lower limit wind speed size, m/s; U is the input in feather actuator dead band; g _ru () is for working as u>=b _rtime feather actuator Dead zone representation; g _lu () is for working as u≤b _ltime feather actuator Dead zone representation;

Step 2.2: to the estimation of nonlinear dynamic function f (x);

In order to design the dead-zone compensator of feather actuator, the present invention must carry out dynamic estimation to controlled system, namely nonlinear dynamic function f (x) for controlled system is estimated, then the estimated value obtained is input to dead-zone compensator as a compensation reference.According to neural network function approximation theory, in present embodiment, estimated by the nonlinear dynamic function of a simple first nerves network to controlled system.Suppose that weights between the hidden layer of this first nerves network and input layer no longer regulate after given at random, then have:

f(x)＝W ₁ ^*Tσ(V ₁ ^TX ₁)+ε1 (4)

In formula: X ₁=[x ₁x ₂x _n1] ^t∈ R ⁿ⁺¹; V ₁for the weight matrix between first nerves network input layer and hidden layer; W ₁ ^*for the desirable weight matrix between first nerves network hidden layer and output layer; ε ₁for first nerves network reconfiguration error; σ is activation primitive, and concrete form is $\mathrm{\&sigma;}\left(z\right)={\left[\begin{array}{cc}\stackrel{\&OverBar;}{\mathrm{\&sigma;}}\left(z\right)& 1\end{array}\right]}^T\&Element;R^{l+1};$

Consider threshold function, the activation primitive in present embodiment is elected as wherein, l is node in hidden layer, and the broad sense that z represents whole system exports; And the output of the first nerves network of reality is

$\hat{f}={W_1}^T\mathrm{\&sigma;}\left({V_1}^T{X}_1\right)---\left(5\right)$

In formula, W ₁for the actual weight matrix between first nerves network hidden layer and output layer;

Then the network-evaluated error of first nerves can be expressed as

$\hat{f}-f\left(x\right)={{\tilde{W}}_1}^T\mathrm{\&sigma;}-{\mathrm{\&epsiv;}}_1---\left(6\right)$

In formula: for neural network weight evaluated error;

Step 2.3: the compensator in design feather actuator dead band, obtains propeller pitch angle offset Δ β _rmathematic(al) representation;

The output of nervus opticus network is utilized in the dead-zone compensator design of feather actuator offset and performed by feather, system fading margin error η (u) that mechanism dead band causes, wherein nervus opticus network is input as u _c;

Nervus opticus network is utilized to obtain propeller pitch angle offset Δ β _rgeneralized Mathematical representation be

In formula: W ₂for the actual weight matrix between nervus opticus network hidden layer and output layer; X ₂=[x ₁x ₂x _n1] ^t∈ R ⁿ⁺¹; V ₂for the weight matrix between nervus opticus network input layer and hidden layer; ε ₂for nervus opticus network reconfiguration error.

As shown in Figure 4, the present invention has added the system deviation that a dead-zone compensator brings to make up feather actuator dead band at place of feather actuator.As shown in Figure 4, Variable-pitch Controller is except will by drawn propeller pitch angle expected value β _rsend to outside feather actuator, also to send feather actuator dead-zone compensator to, meanwhile, feather actuator also will send its final exported propeller pitch angle actual value β to feather actuator dead-zone compensator, dead-zone compensator then by above-mentioned intrinsic nerve network algorithm and error and error set point, finally provides answered propeller pitch angle offset Δ β _r, and sending this propeller pitch angle offset to wind turbine interior phase modulation device, wind turbine interior phase modulation device then receives the propeller pitch angle offset Δ β from feather actuator dead-zone compensator simultaneously _rwith the propeller pitch angle actual value β of feather actuator.The interior phase modulation device of wind turbine regulates wind turbine according to received pitch angle value again.

Step 3: the active-power P that the wind speed v of measure field wind turbine periphery and wind-driven generator export also is sent to Variable-pitch Controller;

Present embodiment adds air velocity transducer and power sensor in wind power generating set, as shown in Figure 4.Air velocity transducer is utilized to measure wind turbine periphery wind speed v, here the EE65 wind speed transducer that air velocity transducer model adopts Shanghai Wei Chuan precision type instrument Co., Ltd to produce, its measuring range is 0-20m/s, output signal is 4-20mA/0-10V, precision is ± 0.2m/s, working environment is-25-50 DEG C, and output signal amplitude is directly proportional to wind speed size.

The power signal of wind-driven generator is input to Variable-pitch Controller through power sensor, finally completes the control of the rated power to wind power generating set.Here power sensor adopts Hall current sensor and Hall voltage sensor to detect electric current and voltage respectively, just obtains the active power of output P of wind-driven generator according to detected Current Voltage.In the present invention, voltage transducer model is the LV 200-AW/2 that lime company of Switzerland (LEM) produces, and the specified effective current in former limit is 20mA, employing ± 15-24V Power supply, and precision is ± 0.5%; Current sensor model is the LA28-NP that lime company of Switzerland (LEM) produces, and the specified effective value electric current in former limit is 25mA, employing ± 15V Power supply, and precision is ± 0.5%, and primary current measuring range is 0 ~ ± 36A.

The active-power P exported by wind speed v and the wind-driven generator of the on-the-spot wind turbine periphery of above sensor measurement is also sent to Variable-pitch Controller.Final measured wherein one group of data and actual wind-power generating system parameter as shown in the table:

Parameter set by table 1 testing wind power generation system

τ＝0.2s	R＝15m	η＝0.871	v f＝28.32
				ρ＝1.25kg/m 2	J g＝32kg·m 2	J r＝350000kg·m 2	v＝9m/s
C 1＝1000N·m	C 3＝100s/rad	C 2＝1000rad/s	ω * r＝22.3(r·min -1)

Step 4: Variable-pitch Controller calculates propeller pitch angle expected value β _rand be sent to the dead-zone compensator of feather actuator and feather actuator respectively;

In the present embodiment, the feather actuator of simulation software MATLAB/Simulink to Wind turbines is utilized to emulate.

The simulation process of present embodiment be based on a rated power be 600KW feather Wind turbines on realize.The structure of first nerves network and nervus opticus network is elected to be respectively into 2-21-1 (namely, input the number of plies be 2, the implicit number of plies be 21 and export the number of plies be 1) and 3-11-1 (that is, input the number of plies be 3, the implicit number of plies be 11 and export the number of plies be 1), the initial value W of weights ₁with settings W ₂be respectively 0.1 and 0.1, the initial value of other the weight at these two networks is set as 0.01.Activation primitive is set as unipolarity S type function

By the parameter that the data setting in table 1 in step 3 is emulated Wind turbines, directly send the data in step 3 measured by sensor to Variable-pitch Controller as input value, then Variable-pitch Controller utilizes the calculated with mathematical model set up in step 1 to go out propeller pitch angle expected value β _r, in the simulation process of present embodiment, can't propeller pitch angle expected value β _rconcrete numerical value show, but be sent to the dead-zone compensator of feather actuator and feather actuator respectively;

Step 5: feather actuator calculates propeller pitch angle actual value β and sends the interior phase modulation device of wind turbine to, meanwhile, the dead-zone compensator of feather actuator calculates propeller pitch angle offset Δ β _ralso the interior phase modulation device of wind turbine is sent to;

In the MATLAB/Simulink emulation of present embodiment, the propeller pitch angle expected value β that step 4 calculates by the simulation model built _rbe updated to the propeller pitch angle expected value β of the Variable-pitch Controller output obtained in step 1 _rmathematic(al) representation and the mathematic(al) representation of propeller pitch angle actual value β that exports of feather actuator, draw feather actuator propeller pitch angle actual value β and send the interior phase modulation device of wind turbine to, meanwhile, the dead-zone compensator of the feather actuator propeller pitch angle expected value β that utilizes the parameter value of table 1 in step 3 and step 4 to obtain according to the mathematic(al) representation in step 2 _rcalculate propeller pitch angle offset Δ β _rand send the interior phase modulation device of wind turbine to;

Step 6: according to the pitch angle value received, i.e. propeller pitch angle actual value β and propeller pitch angle offset Δ β _r, the interior phase modulation device of wind turbine regulates wind turbine.

Accompanying drawing 5 and accompanying drawing 6 are respectively the analogous diagram of the active power of wind turbine rotating speed and wind-driven generator output.As shown in Figure 5, the rotating speed of wind turbine remains near rated speed substantially, and change steadily, does not occur large fluctuation.As can be seen from accompanying drawing 6, active power exports substantially constant, substantially maintains 600KW, and fluctuating up and down is also in very low range.The variable pitch control method that these two analogous diagram well describe the Wind turbines containing dead-zone compensator of the present invention has good effect, substantially counteracts deviation that feather actuator dead band produces to the impact of Wind turbines.

Although the foregoing describe the specific embodiment of the present invention, the those skilled in the art in related domain should be appreciated that these only illustrate, can make various changes or modifications, and do not deviate from principle of the present invention and essence to these mode of executions.Scope of the present invention is only defined by the appended claims.

Claims (4)

1. the Wind turbines variable pitch control method containing dead-zone compensator, is characterized in that: comprise the steps:

Step 1: the mathematical model setting up Wind turbines, obtains the propeller pitch angle expected value β that Variable-pitch Controller exports _rthe mathematic(al) representation of propeller pitch angle actual value β that exports of mathematic(al) representation, feather actuator;

Step 2: according to the result of step 1, the dead-zone compensator of design feather actuator, obtains the mathematic(al) representation of propeller pitch angle offset;

Step 3: the active-power P that the wind speed v of measure field wind turbine periphery and wind-driven generator export also is sent to Variable-pitch Controller;

Step 4: Variable-pitch Controller calculates propeller pitch angle expected value β _rand be sent to the dead-zone compensator of feather actuator and feather actuator respectively;

Step 5: feather actuator calculates propeller pitch angle actual value β and sends the interior phase modulation device of wind turbine to, meanwhile, the dead-zone compensator of feather actuator calculates propeller pitch angle offset Δ β _ralso the interior phase modulation device of wind turbine is sent to;

Step 6: according to the pitch angle value received, i.e. propeller pitch angle actual value β and propeller pitch angle offset Δ β _r, the interior phase modulation device of wind turbine regulates wind turbine.

2. the Wind turbines variable pitch control method containing dead-zone compensator according to claim 1, is characterized in that: the propeller pitch angle expected value β that the Variable-pitch Controller obtained in described step 1 exports _rthe mathematic(al) representation of propeller pitch angle actual value β that exports of mathematic(al) representation, feather actuator, be common relation, shown in (1):

$\mathrm{\&beta;}=\frac{1}{\mathrm{\&tau;s}+1}{\mathrm{\&beta;}}_r---\left(1\right)$

In formula: τ is time constant; S is complex frequency, is supplementing of Fourier transformation;

Obtain the mathematic(al) representation that wind power capability caught by wind turbine, shown in (2) simultaneously:

$C_p(\mathrm{\&lambda;},\mathrm{\&beta;})=(0.44-0.0167\mathrm{\&beta;})\sin \left[\frac{\mathrm{\&pi;}(\mathrm{\&lambda;}-2)}{15-0.3\mathrm{\&beta;}}\right]-0.00184(\mathrm{\&lambda;}-2)\mathrm{\&beta;}---\left(2\right)$

In formula: C _p(λ, β) is power coefficient.

3. the Wind turbines variable pitch control method containing dead-zone compensator according to claim 1, is characterized in that: the dead-zone compensator of the design feather actuator in described step 2, obtains propeller pitch angle offset Δ β _rmathematic(al) representation, method is carried out as follows:

Step 2.1: the mathematical model setting up feather actuator dead band;

The mathematical model in feather actuator dead band is such as formula shown in (3):

$D^{\&prime;}\left(u\right)=\left\{\begin{array}{cc}{g}_r\left(u\right),& u\&GreaterEqual;b_r\\ 0,& b_l<u<b_r\\ g_l\left(u\right),& u\&le;b_l\end{array}\right.---\left(3\right)$

In formula: D ' (u) represents the function expression about feather actuator dead band; b _rfor leaving feather actuator deadband upper limit wind speed size, m/s; b _lfor entering feather actuator deadband lower limit wind speed size, m/s; U is the input in feather actuator dead band; g _ru () is for working as u>=b _rtime feather actuator Dead zone representation; g _lu () is for working as u≤b _ltime feather actuator Dead zone representation;

Step 2.2: utilize first nerves network, estimates nonlinear dynamic function f (x) of Wind turbines;

f(x)＝W ₁ ^*Tσ(V ₁ ^TX ₁)+ε ₁(4)

In formula: X ₁=[X ₁x ₂x _n1] ^t∈ R ⁿ⁺¹; V ₁for the weight matrix between first nerves network input layer and hidden layer; W ₁ ^*for the desirable weight matrix between first nerves network hidden layer and output layer; ε ₁for first nerves network reconfiguration error;

σ is activation primitive, considers threshold function, and activation primitive is elected as wherein, l is the number of hidden nodes, and the broad sense that z represents whole system exports; And the output of the first nerves network of reality, namely the estimated value of nonlinear dynamic function f (x) of Wind turbines is

$\hat{f}={W_1}^T\mathrm{\&sigma;}\left({V_1}^T{X}_1\right)---\left(5\right)$

In formula, W ₁for the actual weight matrix between first nerves network hidden layer and output layer; Then the network-evaluated error of first nerves is expressed as

$\hat{f}-f\left(x\right)={{\tilde{W}}_1}^T\mathrm{\&sigma;}-{\mathrm{\&epsiv;}}_1---\left(6\right)$

In formula: for neural network weight evaluated error;

Step 2.3: the compensator in design feather actuator dead band, and using the estimated value of step 2.2 gained as compensation reference, obtain propeller pitch angle offset Δ β _rmathematic(al) representation;

The output of nervus opticus network is utilized in design of Compensator offset system fading margin error η (u) caused by feather actuator dead band, wherein nervus opticus network is input as u _c;

Nervus opticus network is utilized to obtain propeller pitch angle offset Δ β _rgeneralized Mathematical representation be

In formula: W ₂for the actual weight matrix between nervus opticus network hidden layer and output layer; X ₂=[x ₁x ₂x _n1] ^t∈ R ⁿ⁺¹; V ₂for the weight matrix between nervus opticus network input layer and hidden layer; ε ₂for nervus opticus network reconfiguration error.

4. the Wind turbines variable pitch control method containing dead-zone compensator according to claim 1, it is characterized in that: utilize the wind speed v of air velocity transducer measure field wind turbine periphery in described step 3, utilize Hall voltage, current sensor to record the voltage and current of wind-driven generator output respectively, both are multiplied and obtain the active-power P of wind-driven generator output.