CN104214044A - Independent variable pitch control method of double-fed variable-speed variable-pitch wind generating set - Google Patents

Abstract

The invention provides an independent variable pitch control method of a double-fed variable-speed variable-pitch wind generating set. The method has the following advantages that a band-pass filter is used for filtering load input capacity, signals in a specific frequency range are transformed, and the functions of removing low-frequency drifting and prohibiting high-frequency disturbance can be achieved at the same time; compared with an PI controller, an integrator is used, design difficulty of a controller can be effectively reduced, and the technique has practical application value; an azimuth angle compensation signal capable of reflecting a wind wheel position state can be generated, and accordingly accuracy of a desired output pitch angle of a fan can be maintained at different wind speeds.

Description

The independent pitch of double-fed type speed-changing oar-changing wind power generating set is apart from controlling method

Technical field

The present invention relates to the independent pitch of double-fed type speed-changing oar-changing wind power generating set apart from controlling method, particularly relate to wind generating set pitch control control technique field.

Background technique

Along with the development and perfection of the correlation techniques such as aerodynamics, control theory, Power Electronic Technique, Computer Control Technology, wind generating technology obtains the development of advancing by leaps and bounds, power generating quality improves, and cost of electricity-generating declines, and blower sizes and single-machine capacity constantly increase.But the Enlargement Tendency of wind power generating set also brings the technical problem of some complexity simultaneously.Wherein the most outstanding one is exactly, wind shear effect and tower shadow effect can cause the skewness of effective wind speed in wind wheel plane, blade can bear periodically variable aerodynamic force in rotation process, according to foline theory, the aerodynamic force of blade can be analyzed to again axial force and peripheral force, and the axial force of acute variation can make blade even pylon wave shimmy.The vibration brought thus and fatigue load problem not only affect the stability of blower fan work, and excessive fatigue stress easily causes the fatigue damage of blower fan associated components, cause various accident.The rotor diameter of unit is larger, and this problem just seems more serious.So the aerodynamic loading fatigue effectively reducing blade has become one of important content of wind power generating set maximization research.Obviously carry out controlling separately to solve the problem to each blade of wind power generating set.

Independent pitch is apart from referring to that each blade of wind energy conversion system changes propeller pitch angle independently according to respective control law.Independent pitch is the Novel pitch distance control theory and method that grow up on the basis of unified variable propeller pitch in recent years apart from control.Independent pitch apart from control not only with stable output power for controlling object, and effectively can also solve the load problem of non-uniform of the parts such as blade and pylon.Independent pitch, apart from the actual wind speed size adjustment propeller pitch angle controlling to be subject to according to pneumatic equipment blades made, makes wind mill wind wheel blade remain at the state of optimum tip-speed ratio.When wind energy conversion system works, the output power that can reduce wind energy conversion system resistance, reduce the internal stress of pneumatic equipment blades made, improve wind energy conversion system, thus extend the working life of pneumatic equipment blades made.Although install corresponding measuring device can increase separate unit wind energy conversion system cost, the generating capacity of whole wind energy turbine set improves to some extent, and also there is increase the service life of wind power generating set, and this will make the economic benefit of wind energy turbine set be improved significantly.

Consider from aerodynamics angle, when wind speed changes, the propeller pitch angle of wind machine oar leaf must make corresponding changes, and makes air-flow keep best to the angle of attack of blade, power coefficient just can be made to reach the highest.The institute during design of variable speed pitch wind wind power generating set is it is considered that the pitch that will realize at certain wind speed apparatus for lower wind machine wind wheel blade changes, and then the angle of attack of change blade.The change of each blade of wind wheel is synchronous, and namely each blade keeps identical propeller pitch angle at any time.But in fact wind speed with highly there is shear, wind speed can along with height increase and increase, the degree of increase depends on wind shear coefficient.Because wind speed is different in wind mill wind wheel swept surface, so the tip speed ratio of each blade arbitrary position in rotor swept face of blower fan is also different.According to the relation of tip speed ratio and the wind energy conversion system angle of attack, the angle of attack of pneumatic equipment blades made in whole swept surface is with the change that one-period highly occurs.According to the relation of lift coefficient and the angle of attack, resistance coefficient and the angle of attack, can know that the lift that each blade obtains at any time and resistance are different.Like this, just a problem is existed for the wind energy conversion system adopting unified variable propeller pitch to control: wind energy conversion system is in operation and there is extra resistance.Pneumatic equipment blades made will bear the extra internal stress that the unbalance stress due to blade causes, and the moment changes with the rotation of wind energy conversion system to cause blade loading.Analyze known in theory, from load angle, wind energy conversion system is implemented to control to obtain revising variable pitch control and can weaken the impact of this part fluctuations in wind speed on wind energy conversion system, both the unbalanced load that independent feathering control can reduce on wind wheel was to a certain extent carried out to each blade.

Prior art is all generally utilize generator speed deviation to generate collaborative change oar pitch angle and measure wind wheel azimythal angle and root of blade load (M _y1, M _y2, M _y3) mode generate deviation and become oar pitch angle, the Chinese patent of patent publication No. CN102102630A adopts generator power deviation to generate the y direction load (M that collaborative pitch angle measures wind wheel azimythal angle and root of blade _y1, M _y2, M _y3) and z direction load (M _z1, M _z2, M _z3) generate deviation pitch angle.Above several method both increases and becomes oar speed, also comes with some shortcomings simultaneously: (1) this by increasing the fatigue load of pitch variable bearings, therefore, the life-span of pitch variable bearings can be reduced; (2) become oar speed to accelerate to require to improve to the speed of response of motor, may need to change performance pitch motor more reliably; (3) the third method needs the blade root load measuring both direction, therefore needs more optical fiber transducer, therefore needs to increase more hardware cost; (4) because variable pitch control has certain hysteresis quality, can there is deviation as input quantity to the calculating of deviation pitch angle in the azimythal angle recorded.

Summary of the invention

The object of the invention is the defect existed for above-mentioned background technology, a kind of unbalanced load by measuring on wind wheel azimythal angle and blade is provided, reduce the controlling method of associated components fatigue load and independent pitch cost, this controlling method utilizes classical control theory to design relatively simple control strategy and realizes independent feathering control, reduce the calculation task of master controller, have the advantages that easily realize.

For achieving the above object, the independent pitch of double-fed type speed-changing oar-changing wind power generating set of the present invention, apart from controlling method, comprising:

Steps A: unified change oar control section, namely goes out the given β of unified propeller pitch angle by unified variable propeller pitch controlling calculation;

Step B: independent feathering control part, this step B comprises further:

Step 1: measure three root of blade y direction load (M respectively by load transducer and absolute value encoder _y1, M _y2, M _y3) and wind wheel azimythal angle ψ;

Step 2: utilize master controller by the y direction load (M of three paddle blade roots _y1, M _y2, M _y3) and wind wheel azimythal angle ψ carry out Coleman conversion, be transformed to tipping load component M _tiltwith driftage sharing part of the load M _yaw;

Step 3: two sharing part of the load M _tilt, M _yawrespectively change into corresponding propeller pitch angle component by the integrator of band gain, namely draw the propeller pitch angle (θ of d axle and q axle desired output ₂, θ ₃), θ ₂, θ ₃be respectively the change vane angle that conversion obtains true dip direction under d-q axle and yaw direction;

Step 4: provide wind wheel orientation offset angle Δ ψ and carry out add operation with wind wheel azimythal angle ψ: ψ+Δ ψ, by the result after computing together with expectation propeller pitch angle (θ ₂, θ ₃) carry out Coleman inverse transformation, can show that independent pitch is apart from the given (β in independent pitch angle controlling desired output ₁, β ₂, β ₃);

Step 5: to the given (β in independent pitch angle exported ₁, β ₂, β ₃) carry out lower pass-filter and the rear output of propeller pitch angle size restriction process respectively;

Step C: by the given (β in independent pitch angle processed through step 5 ₁, β ₂, β ₃) carry out add operation with the given β of unified propeller pitch angle respectively after, export the given (β+β of propeller pitch angle of blade 1 ₁), the given (β+β of propeller pitch angle of blade 2 ₂) and the given (β+β of the propeller pitch angle of blade 3 ₃).

In sum, the independent pitch of double-fed type speed-changing oar-changing wind power generating set of the present invention has the following advantages apart from controlling method tool:

1. use band-pass filter to carry out filtering to load input quantity, the signal in particular frequency range is brought conversion, the effect of removing low frequency wonder and suppressing high frequency components can be realized simultaneously;

2., relative to PI controller, adopt integrator effectively can reduce the design difficulty of controller, make this technology more have actual application value;

3. can produce the azimythal angle compensating signal of a reflection rotor position state, make wind power generating set under different wind speed, keep the accuracy of desired output propeller pitch angle.

Accompanying drawing explanation

Fig. 1 is that the independent pitch of double-fed type speed-changing oar-changing wind power generating set of the present invention is apart from controlling method Baseline Control Strategy schematic diagram.

Fig. 2 is that the independent pitch of double-fed type speed-changing oar-changing wind power generating set of the present invention is apart from the concrete control strategy schematic diagram of controlling method.

Fig. 3 is the schematic diagram of independent pitch apart from wind power generating set blade load system of coordinates in controlling method of double-fed type speed-changing oar-changing wind power generating set of the present invention.

Fig. 4 is the schematic diagram of independent pitch apart from wind power generating set hubload system of coordinates in controlling method of double-fed type speed-changing oar-changing wind power generating set of the present invention.

Embodiment

By describing technology contents of the present invention, structure characteristics in detail, being reached object and effect, hereby exemplify embodiment below and coordinate accompanying drawing to be explained in detail.

Refer to Fig. 1, the independent pitch of double-fed type speed-changing oar-changing wind power generating set of the present invention includes unified variable propeller pitch control procedure and independent pitch distance control procedure apart from controlling method.

Unified variable propeller pitch controls to calculate the given β of unified propeller pitch angle;

Independent pitch is given apart from the independent pitch angle controlling acquisition three blades, and then add unified propeller pitch angle setting value on this basis respectively, the propeller pitch angle that can obtain three blades is given.

Below in conjunction with Fig. 1 to Fig. 4, this correlation technique is described in detail.

First preferred embodiment of the independent pitch distance controlling method of double-feedback aerogenerator group of the present invention, it comprises:

Steps A: unified change oar control section, namely goes out the given β of unified propeller pitch angle by unified variable propeller pitch controlling calculation;

Step B: independent feathering control part, this step B comprises further:

Step 1: measure three blade root y direction load (M respectively by load transducer and absolute value encoder _y1, M _y2, M _y3) and wind wheel azimythal angle ψ;

Step 2: utilize master controller by the y direction load (M of three paddle blade roots _y1, M _y2, M _y3) and wind wheel azimythal angle ψ carry out Coleman conversion, be transformed to tipping load component M _tiltwith driftage sharing part of the load M _yaw;

Step 3: two sharing part of the load M _tilt, M _yawrespectively change into corresponding propeller pitch angle component by the integrator of band gain, namely draw the propeller pitch angle (θ of d axle and q axle desired output ₂, θ ₃), θ ₂, θ ₃be respectively the change vane angle that conversion obtains true dip direction under d-q axle and yaw direction;

Step 4: provide wind wheel orientation offset angle Δ ψ and carry out add operation with wind wheel azimythal angle ψ: ψ+Δ ψ, by the result after computing together with expectation propeller pitch angle (θ ₂, θ ₃) carry out Coleman inverse transformation, can show that independent pitch is apart from the given (β in independent pitch angle controlling desired output ₁, β ₂, β ₃);

Step 5: to the given (β in independent pitch angle exported ₁, β ₂, β ₃) carry out lower pass-filter and the rear output of propeller pitch angle size restriction process respectively;

Step C: by the given (β in independent pitch angle processed through step 5 ₁, β ₂, β ₃) carry out add operation with the given β of unified propeller pitch angle respectively after, export the given (β+β of propeller pitch angle of blade 1 ₁), the given (β+β of propeller pitch angle of blade 2 ₂) and the given (β+β of the propeller pitch angle of blade 3 ₃).

Load transducer in step 1 adopts optical fiber load transducer to carry out root of blade y direction load (M _y1, M _y2, M _y3) measurement.

In whole control procedure, in order to avoid signal drift and High-frequency Interference, three root of blade load (M _y1, M _y2, M _y3) before transformation of coordinates, namely before step 2, first will carry out filtering process through a band-pass filter, its representation is:

$G\left(s\right)=K_{\mathrm{nd}}\frac{2\mathrm{\ζs}/{\mathrm{\ω}}_1}{1+2\mathrm{\ζs}/{\mathrm{\ω}}_1+s^2/{{\mathrm{\ω}}_1}^2}$

In formula, K _ndgain, ω ₁for the natural frequency of band-pass filter, usually get the integral multiple of blade passing frequency, ζ is the damping ratio of band-pass filter.

In step 2, the effect of Coleman conversion is that input quantity is transformed into non-rotated coordinate system from mixed proportion (comprising rotating coordinate system and non-rotated coordinate system), realizes the change of variable between blade vane rotary system of coordinates and wheel hub fixed coordinate system.Its formula is:

$\left[\begin{array}{c}{M}_{\mathrm{tilt}}\\ M_{\mathrm{yaw}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\ωt}\right)& \cos (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})& \cos (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})\\ \sin \left(\mathrm{\ωt}\right)& \sin (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})& \sin (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{M}_{y1}\\ M_{y2}\\ M_{y3}\end{array}\right]$

In formula: M _y1, M _y2, M _y3for the load moment recorded on root of blade; M _tilt, M _yawfor transforming to tilting moment on two perpendicular d-q axles and yawing moment, then change into propeller pitch angle component (θ by tilting moment and yawing moment ₂, θ ₃), after transformation of coordinates, system is modeled as linear time invariant system, and the analytical method of conventional linear time invariant system can be adopted to carry out eigenvalue calculating.

In step 3, integrator is used for the sharing part of the load to change into propeller pitch angle component (θ ₂, θ ₃), its representation is:

in formula, K is storage gain, T _iit is integration time constant.

Coleman inverse transformation is the independent pitch angle (β in order to propeller pitch angle component transformation being become desired output ₁, β ₂, β ₃).The representation of Coleman inverse transformation is:

$\left[\begin{array}{c}{\mathrm{\β}}_1\\ {\mathrm{\β}}_2\\ {\mathrm{\β}}_3\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\ωt}\right)& \sin \left(\mathrm{\ωt}\right)\\ \cos (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})& \sin (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})\\ \cos (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})& \sin (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{\mathrm{\θ}}_2\\ {\mathrm{\θ}}_3\end{array}\right]$

In formula: β ₁, β ₂, β ₃for the fine setting of three blades calculated becomes vane angle, also namely the independent pitch distance of three blades controls the independent pitch angle of desired output; θ ₂, θ ₃for conversion obtains the change vane angle of true dip direction under d-q axle and yaw direction.

Because the variable pitch control of wind generating set pitch control distance control system has certain hysteresis quality, then wind wheel azimythal angle during input and output has deviation, and greatly, deviate is larger, often easily affects the given of independent pitch angle in wind speed change.In order to make the given output value in independent pitch angle more accurate, adding azimythal angle when carrying out Coleman inverse transformation in step 4 and compensating Δ ψ.This offset Δ ψ can be fixed value, also can according to become oar control dynamic characteristic calculate any one, when adopt according to become oar control dynamic characteristic carry out computer azimuth offset Δ ψ time, the formula of employing is: Δ ψ=ω _r* T, in formula: ω _rbe the angular velocity that wind wheel rotates, T is the operation period becoming oar controller.

The low-pass filter of the independent pitch distance controlling method step 5 of double-fed type speed-changing oar-changing wind power generating set of the present invention is used to stop in propeller pitch angle output quantity and occurs undesirable frequency, and become the sensitivity of oar controller when being reduced in high frequency components, its transfer function is:

$G\left(s\right)=\frac{1}{1+2\mathrm{\ζs}/{\mathrm{\ω}}_2+s^2/{{\mathrm{\ω}}_2}^2}$

In formula, ω ₂for the natural frequency of low-pass filter, ζ is the damping ratio of low-pass filter.

The step C of the independent pitch distance controlling method of double-fed type speed-changing oar-changing wind power generating set of the present invention includes the size conditioning step to desired output propeller pitch angle further, and this step effectively can suppress the increase becoming oar speed.

In actual moving process, becoming vane angle needs to control in limited range because being subject to the constraint of executive component machinery and physical property, therefore in step C, exports the given (β+β of propeller pitch angle of three blades (1,2,3) ₁), (β+β ₂), (β+β ₃) before, utilize saturation integral amplitude limiter limit the amplitude of desired output propeller pitch angle and become the size of oar speed, change vane angle is limited in β further _min≤ β (t)≤β _max, its variance ratio also has certain limited field, namely saturation integral amplitude limiter is utilized can effectively to suppress independent feathering control to become the increase of oar speed.

The independent pitch of the double-fed type speed-changing oar-changing wind power generating set of the second preferred embodiment is apart from unique difference of controlling method with the first preferred embodiment: do not provide wind wheel orientation offset angle Δ ψ in step 4, namely direct by wind wheel azimythal angle ψ together with expecting propeller pitch angle (θ ₂, θ ₃) carry out Coleman inverse transformation, can show that independent pitch is apart from the independent pitch angle (β controlling desired output ₁, β ₂, β ₃).

In sum, the independent pitch of double-fed type speed-changing oar-changing wind power generating set of the present invention has the following advantages apart from controlling method tool:

1. use band-pass filter to carry out filtering to load input quantity, the signal in particular frequency range is brought conversion, the effect of removing low frequency wonder and suppressing high frequency components can be realized simultaneously;

2., relative to PI controller, adopt integrator effectively can reduce the design difficulty of controller, make this technology more have actual application value;

3. can produce the azimythal angle compensating signal of a reflection rotor position state, make wind power generating set under different wind speed, keep the accuracy of desired output propeller pitch angle.

Above-described technological scheme is only the preferred embodiment of independent pitch apart from controlling method of double-fed type speed-changing oar-changing wind power generating set of the present invention, and the equivalent transformation that any independent pitch in double-fed type speed-changing oar-changing wind power generating set of the present invention is done on controlling method basis or replacement are included within the scope of the claim of this patent.

Claims (11)

1. the independent pitch of double-fed type speed-changing oar-changing wind power generating set is apart from controlling method, comprising:

Steps A: unified change oar control section, namely calculates the given β of unified propeller pitch angle by unified variable propeller pitch control algorithm;

Step B: independent feathering control part, this step B comprises further:

Step 1: measure three root of blade y direction load (M respectively by load transducer and absolute value encoder _y1, M _y2, M _y3) and wind wheel azimythal angle ψ;

Step 2: utilize master controller by the y direction load (M of three blade roots _y1, M _y2, M _y3) and wind wheel azimythal angle ψ carry out Coleman conversion, be transformed to tipping load component M _tiltwith driftage sharing part of the load M _yaw;

Step 3: two sharing part of the load M _tilt, M _yawrespectively change into corresponding propeller pitch angle component by the integrator of band gain, namely draw the propeller pitch angle (θ of d axle and q axle desired output ₂, θ ₃), θ ₂, θ ₃be respectively the change vane angle that conversion obtains true dip direction under d-q axle and yaw direction;

Step 4: provide wind wheel orientation offset angle Δ ψ and carry out add operation with wind wheel azimythal angle ψ: ψ+Δ ψ, by the result after computing together with expectation propeller pitch angle (θ ₂, θ ₃) carry out Coleman inverse transformation, can show that independent pitch is apart from the given (β in independent pitch angle controlling desired output ₁, β ₂, β ₃);

Step 5: to the given (β in independent pitch angle exported ₁, β ₂, β ₃) carry out lower pass-filter and the rear output of propeller pitch angle size restriction process respectively;

Step C: by the given (β in independent pitch angle processed through step 5 ₁, β ₂, β ₃) carry out add operation with the given β of unified propeller pitch angle respectively after, export the given (β+β of propeller pitch angle of blade 1 ₁), the given (β+β of propeller pitch angle of blade 2 ₂) and the given (β+β of the propeller pitch angle of blade 3 ₃).

2. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 1 is apart from controlling method, it is characterized in that: the load transducer in step 1 adopts optical fiber load transducer to carry out root of blade y direction load (M _y1, M _y2, M _y3) measurement.

3. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 1 is apart from controlling method, it is characterized in that: in whole change oar control procedure, in order to avoid signal drift and High-frequency Interference, root of blade load (M _y1, M _y2, M _y3) before transformation of coordinates, namely before step 2, first will carry out filtering process through a band-pass filter, its representation is:

$G\left(s\right)=K_{\mathrm{nd}}\frac{2\mathrm{\ζs}/{\mathrm{\ω}}_1}{1+2\mathrm{\ζs}/{\mathrm{\ω}}_1+s^2/{{\mathrm{\ω}}_1}^2}$

In formula, K _ndgain, ω ₁for the natural frequency of band-pass filter, usually get the integral multiple of blade passing frequency, ζ is the damping ratio of band-pass filter.

4. the independent pitch of the double-fed type speed-changing oar-changing wind power generating set according to Claims 2 or 3 is apart from controlling method, it is characterized in that: in step 2, the effect of Coleman conversion is that input quantity is transformed into non-rotated coordinate system from mixed proportion (comprising rotating coordinate system and non-rotated coordinate system), realize the change of variable between blade vane rotary system of coordinates and wheel hub fixed coordinate system, its formula is:

$\left[\begin{array}{c}{M}_{\mathrm{tilt}}\\ M_{\mathrm{yaw}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\ωt}\right)& \cos (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})& \cos (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})\\ \sin \left(\mathrm{\ωt}\right)& \sin (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})& \sin (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{M}_{y1}\\ M_{y2}\\ M_{y3}\end{array}\right]$

In formula: M _y1, M _y2, M _y3for the load moment recorded on root of blade; M _tilt, M _yawfor transforming to tilting moment on two perpendicular d-q axles and yawing moment, then change into propeller pitch angle component (θ by tilting moment and yawing moment ₂, θ ₃), after transformation of coordinates, system is modeled as linear time invariant system from periodic system, and the analytical method of conventional linear time invariant system can be adopted to carry out eigenvalue calculating.

5. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 4 is apart from controlling method, it is characterized in that: in step 3, and integrator is used for the sharing part of the load to change into propeller pitch angle component (θ ₂, θ ₃), its representation is: in formula, K is storage gain, T _iit is integration time constant.

6. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 1 is apart from controlling method, it is characterized in that: Coleman inverse transformation is the independent pitch angle (β in order to propeller pitch angle component transformation being become desired output ₁, β ₂, β ₃), the representation of Coleman inverse transformation is: $\left[\begin{array}{c}{\mathrm{\β}}_1\\ {\mathrm{\β}}_2\\ {\mathrm{\β}}_3\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\ωt}\right)& \sin \left(\mathrm{\ωt}\right)\\ \cos (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})& \sin (\mathrm{\ωt}+\frac{2\mathrm{\π}}{3})\\ \cos (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})& \sin (\mathrm{\ωt}+\frac{4\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{\mathrm{\θ}}_2\\ {\mathrm{\θ}}_3\end{array}\right]$

In formula: β ₁, β ₂, β ₃for the fine setting of three blades calculated becomes vane angle, also namely the independent pitch distance of three blades controls the independent pitch angle of desired output; θ ₂, θ ₃for conversion obtains the change vane angle of true dip direction under d-q axle and yaw direction.

7. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 1 is apart from controlling method, it is characterized in that: add azimythal angle when carrying out Coleman inverse transformation in step 4 and compensate Δ ψ, this offset Δ ψ can be fixed value, also can calculate according to the dynamic characteristic becoming oar control.

8. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 7 is apart from controlling method, it is characterized in that: when adopting the dynamic characteristic controlled according to change oar to carry out computer azimuth offset Δ ψ, the formula of employing is: Δ ψ=ω _r* T, in formula: ω _rbe the angular velocity that wind wheel rotates, T is the operation period becoming oar controller.

9. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 1 is apart from controlling method, it is characterized in that: the low-pass filter of step 5 is used to stop in propeller pitch angle output quantity and occurs undesirable frequency, become the sensitivity of oar controller when being reduced in high frequency components, its transfer function is: in formula, ω ₂for the natural frequency of low-pass filter, ζ is the damping ratio of low-pass filter.

10. the independent pitch of double-fed type speed-changing oar-changing wind power generating set according to claim 1 is apart from controlling method, it is characterized in that: in step C, exports the given (β+β of propeller pitch angle of blade (1,2,3) ₁), (β+β ₂), (β+β ₃) before, utilize saturation integral amplitude limiter limit the amplitude of desired output propeller pitch angle and become the size of oar speed further.

The independent pitch of 11. double-fed type speed-changing oar-changing wind power generating set, apart from controlling method, comprising:

Steps A: unified change oar control section, namely goes out the given β of unified propeller pitch angle by unified variable propeller pitch controlling calculation;

Step B: independent feathering control part, this step B comprises further:

Step 1: measure three root of blade y direction load (M respectively by load transducer and absolute value encoder _y1, M _y2, M _y3) and wind wheel azimythal angle ψ;

Step 2: utilize master controller by the y direction load (M of three paddle blade roots _y1, M _y2, M _y3) and wind wheel azimythal angle ψ carry out Coleman conversion, be transformed to tipping load component M _tiltwith driftage sharing part of the load M _yaw;

Step 3: two sharing part of the load M _tilt, M _yawrespectively change into corresponding propeller pitch angle component by the integrator of band gain, namely draw the propeller pitch angle (θ of d axle and q axle desired output ₂, θ ₃), θ ₂, θ ₃be respectively the change vane angle that conversion obtains true dip direction under d-q axle and yaw direction;

Step 4: to expectation propeller pitch angle (θ ₂, θ ₃) carry out Coleman inverse transformation, can show that independent pitch is apart from the given (β in independent pitch angle controlling desired output ₁, β ₂, β ₃);

Step 5: to the given (β in independent pitch angle exported ₁, β ₂, β ₃) carry out lower pass-filter and the rear output of propeller pitch angle size restriction process respectively;

Step C: by the given (β in independent pitch angle processed through step 5 ₁, β ₂, β ₃) carry out add operation with the given β of unified propeller pitch angle respectively after, export the given (β+β of propeller pitch angle of blade 1 ₁), the given (β+β of propeller pitch angle of blade 2 ₂) and the given (β+β of the propeller pitch angle of blade 3 ₃).