CN102926930B - Independent variable pitch control method of wind power generation system - Google Patents

Abstract

The invention discloses an independent variable pitch control method of a wind power generation system. The independent variable pitch control method of the wind power generation system is characterized in that a control system adopted in the control method comprises two control closed loops, namely a balanced load control closed loop and an unbalanced load control closed loop, are respectively used to deal with a load balanced situation and a load unbalanced situation of a wind turbine. On the condition of balance, the balanced load control closed loop is used to eliminate load on blades and on a fixed portion of the wind turbine; and when the unbalanced load is detected, the unbalanced load control closed loop is started to eliminate fatigue load on a hub and the fixed portion of the wind turbine. Under the conditions that the wind turbine load is balanced or unbalanced, the independent variable pitch control method of the wind power generation system not only reduces the load on the blades, the load of the fixed portion of the wind turbine is also reduced greatly.

Description

A kind of independent pitch control method of wind-power generating system

Technical field

The present invention relates to wind power generation field, particularly the independent pitch control method of wind-power generating system.

Background technique

Along with the whole society is to the giving more sustained attention of energy crisis and environmental pollution problem, the renewable energy sources particularly exploitation of wind-power electricity generation is just presenting the trend of accelerated development.Along with the increase of wind turbine pool-size, the height of the rotor diameter of wind energy conversion system, the weight in cabin, pylon all increases rapidly, to such an extent as to the factors such as wind shear, tower shadow effect, wind turbulent flow produce increasing load on wind energy conversion system, finally can reduce the service life of wind energy conversion system.

At present, popular wind-power generating system is main on rated wind speed adopts the unified oar control that becomes, and by controlling three, to overlap the propeller pitch angle of three blades of blade pitch device control independently identical, thereby reduce catching of wind energy, makes wind-powered electricity generation unit amount of exports determine power.But the load, particularly fatigue loading of wind energy conversion system are not considered in the control of this unified change oar, and along with the increase of wind energy conversion system capacity, the problem of load is more and more obvious and urgently to be resolved hurrily.

The target of the independent feathering control before proposing is both at home and abroad mainly the 1p load reducing on blade, thereby reduces the 0p load of wind wheel hub and standing part.But the fatigue loading of wind energy conversion system standing part is mainly because 3p load causes, therefore the fatigue loading of its standing part does not reduce.

The main policies of the independent feathering control before proposing is both at home and abroad to detect the bending moment M of three propeller shanks ₁, M ₂, M ₃the azimythal angle (azimuth angle) of (blade root bending moment) and rotor, converts M by Coleman afterwards ₁, M ₂, M ₃be transformed to pitch moment M _tiltwith yawing moment M _yaw.In order to reduce the impact of other higher harmonicss, conventionally at M _tiltand M _yawafter signal, add two low-pass filters (LPF), afterwards the propeller pitch angle θ corresponding to pitch moment and yawing moment by controller (PI, LQG etc.) output _tiltand θ _yaw, the increment θ of three blade angles expecting through Coleman inverse transformation output _b1, θ _b2, θ _b3.θ _b1, θ _b2, θ _b3be added the total propeller pitch angle of output with the unified propeller pitch angle that becomes oar output respectively again and give respectively the servo-system of three blades, thereby reduce the 0p load on 1p load and the wheel hub on blade.If wish to eliminate the fatigue loading of wind energy conversion system wheel hub and standing part, need to eliminate respectively 2p and the 4p load on blade by similar control strategy.As can be seen here, in order to eliminate the load of wind energy conversion system, existing independent pitch system need to, through repeatedly complicated Coleman conversion and inverse transformation, need multiple low-pass filters and multiple controller, and control system is quite complicated.

In addition, the independent feathering control technology overwhelming majority who proposes both at home and abroad does not consider the situation that wind energy conversion system is load unbalanced, but in the process of wind energy conversion system operation, the quality of blade may change, or blade damages to some extent, or on blade, can freeze etc. in the situation that temperature is low, all can cause the imbalance of wind energy conversion system load, increase fatigue load, therefore can reduce the service life of wind energy conversion system.

Summary of the invention

Technical problem: in view of deficiency and the complexity of existing wind-power generating system independent feathering control, the object of the present invention is to provide a kind of independent pitch control method of wind-power generating system, in wind energy conversion system balancing the load or unbalanced situation, not only can reduce the load on blade, the load of wind energy conversion system standing part has also obtained reducing.The method has been simplified the complexity of control system, reduces costs, and has improved arithmetic speed, and reliability is high, can more effectively reduce the fatigue load of wind energy conversion system.

Technological scheme: for solving the problems of the technologies described above, the invention provides a kind of independent pitch control method of wind-power generating system, the control system that this controlling method adopts comprises two Control loops, be balanced load Control loop and uncompensated load Control loop, be used for respectively processing wind energy conversion system balancing the load and unbalanced situation, under balance, balance load Control loop is eliminated load on blade and the load of wind energy conversion system standing part; In the time load uneven being detected, start uncompensated load Control loop to eliminate its fatigue load to wind energy conversion system wheel hub and standing part, the method comprises:

When wind energy conversion system balancing the load:

Step 11: the bending moment M that detects respectively three propeller shanks ₁, M ₂, M ₃give master controller, master controller is by the bending moment M of three propeller shanks ₁, M ₂, M ₃two vertical component M when conversion is converted to wind energy conversion system balancing the load through Clarke _α, M _β;

Step 12: two vertical component M when wind energy conversion system balancing the load _α, M _βsignal is given the first ratio resonant controller, and output, corresponding to α, is expected propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _β,

Step 13: corresponding to α, expect propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _βthrough Clarke, inverse transformation obtains three blades propeller pitch angle increment size θ in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3,

Step 14: the propeller pitch angle increment size θ of three blades in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3during respectively with wind energy conversion system balancing the load, unify the setting value θ of propeller pitch angle _cbe added propeller pitch angle θ while exporting total wind energy conversion system balancing the load _c+ θ _b1, θ _c+ θ _b2, θ _c+ θ _b3give respectively the servo-system of three blades;

When wind energy conversion system is load unbalanced:

Step 21: by the bending moment M of three propeller shanks ₁, M ₂, M ₃give master controller with azimuth signal, obtain wind energy conversion system two vertical component M when load unbalanced through Coleman conversion _dand M _q;

Step 22: vertical component M when wind energy conversion system is load unbalanced _d, M _qsignal is given the second ratio resonant controller, and output, corresponding to d, is expected propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _q,

Step 23: corresponding to d, expect propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _qobtain the propeller pitch angle increment size θ of wind energy conversion system three blades when load unbalanced through Coleman inverse transformation _i1, θ _i2, θ _i3,

Step 24: the propeller pitch angle increment size θ of three blades when wind energy conversion system is load unbalanced _i1, θ _i2, θ _i3propeller pitch angle reference value during respectively with wind energy conversion system balance is added, total propeller pitch angle θ when output wind energy conversion system is load unbalanced _c+ θ _b1+ θ _i1, θ _c+ θ _b2+ θ _i2, θ _c+ θ _b3+ θ _i3give respectively the servo-system of three blades.

Preferably, in step 11, the bending moment M of three propeller shanks ₁, M ₂, M ₃two vertical component M when conversion is converted to wind energy conversion system balancing the load through Clarke _α, M _β, specifically realize by the following method:

$\left[\begin{array}{c}{M}_{\mathrm{\&alpha;}}\\ M_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

Preferably, the independent pitch control method of wind-power generating system, is characterized in that:

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="c\; s\; s"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">c</figure-callout>}}s}{s^{}}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hbe the resonance coefficient of the first ratio resonant controller, ω ₀for resonant frequency, ω _cin order to prevent G _pR(s) parameter of the too large introducing of gain; ω _c<< ω ₀, h=1,2,4; S is Laplace operator, G _pR(s) be the transfer function of the first ratio resonant controller.

Preferably, step 13, corresponding to α, expects propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _βthrough Clarke, inverse transformation obtains three blades propeller pitch angle increment size θ in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3,

Realize by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="3"\; label="b"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">b</figure-callout>}3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right].$

Preferably, step 21, by the bending moment M of three propeller shanks ₁, M ₂, M ₃give master controller with azimuth signal, obtain wind energy conversion system two vertical component M when load unbalanced through Coleman conversion _dand M _q; Realize by the following method:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

Preferably, in step 22, the transfer function of the second ratio resonant controller is:

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="c\; s\; s"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">c</figure-callout>}}s}{s^{}}$

Wherein P _1pand K _1pbe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀for resonant frequency, ω _cin order to prevent G _pR1p(s) parameter of the too large introducing of gain, s is Laplace operator, G _pR1p(s) be the transfer function of the second ratio resonant controller.

Preferably, step 23, corresponding to d, expects propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _qobtain the propeller pitch angle increment size θ of wind energy conversion system three blades when load unbalanced through Coleman inverse transformation _i1, θ _i2, θ _i3, embody by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{i1}\\ {\mathrm{\&theta;}}_{i2}\\ {\mathrm{\&theta;}}_{i3}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\&omega;t}\right)& \sin \left(\mathrm{\&omega;t}\right)\\ \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})\\ \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_d\\ {\mathrm{\&theta;}}_q\end{array}\right].$

Beneficial effect: the independent feathering control relatively, this independent feathering control is in the time of wind energy conversion system balance, save the azimuthal detection of wind energy conversion system, saved the repeatedly transformation of coordinates between rotation and the rest frame of complexity, the use of simultaneously having saved some low-pass filters.This control strategy can reduce 1p on blade, the load of 2p and above high secondary frequencies, and the 3p that can reduce wind energy conversion system wheel hub and standing part simultaneously loads.In the time that wind energy conversion system is uneven, this independent feathering control strategy has added the control of uncompensated load outside balanced load control, can effectively reduce the 1p load of wind energy conversion system standing part.

This independent feathering control technology can reduce the fatigue load of system more effectively, has simple in structurely, and processing rate is fast, and reliability high can effectively extend working life of wind energy conversion system.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of the independent feathering control of the technology of the present invention;

Fig. 2 is the spectrogram of propeller shank bending moment;

Fig. 3 is pitch moment M _tiltspectrogram;

Fig. 4 is yawing moment M _yawspectrogram;

Fig. 5 is the propeller pitch angle schematic diagram of independent feathering control;

Fig. 6 is the pitch moment M of wind energy conversion system when load unbalanced _tiltschematic diagram;

Fig. 7 is the yawing moment M of wind energy conversion system when load unbalanced _yawschematic diagram.

Embodiment

Below in conjunction with accompanying drawing, the present invention will be further described.

The independent pitch control method of wind-power generating system provided by the invention, this controlling method, in the time of wind energy conversion system balancing the load and imbalance, can reduce by corresponding control strategy the load of wind energy conversion system.In the time of wind energy conversion system balancing the load, compared with traditional independent feathering control strategy, this independent feathering control strategy can save the azimuthal detection of wind energy conversion system and the repeatedly transformation of coordinates between complicated rotation and rest frame, has saved some low-pass filters simultaneously.This control strategy can reduce 1p on blade, and the load of 2p and above high secondary frequencies reduces the 3p load on wind energy conversion system wheel hub simultaneously.In the time that wind energy conversion system is load unbalanced, this independent feathering control strategy has added the control of uncompensated load outside balanced load control, can effectively reduce the 1p load on the standing parts such as wind energy conversion system wheel hub.This independent feathering control can reduce the fatigue load of wind energy conversion system effectively, extends its service life.

The independent pitch control method of wind-power generating system provided by the invention, the control system adopting comprises two Control loops, be balanced load Control loop and uncompensated load Control loop, be used for respectively processing wind energy conversion system balancing the load and unbalanced situation, under balance, balance load Control loop is eliminated load on blade and the load of wind energy conversion system standing part; In the time load uneven being detected, start uncompensated load Control loop to eliminate its fatigue load to wind energy conversion system wheel hub and standing part, the method comprises:

When wind energy conversion system balancing the load:

Step 11: the bending moment M that detects respectively three propeller shanks ₁, M ₂, M ₃give master controller, master controller is by the bending moment M of three propeller shanks ₁, M ₂, M ₃two vertical component M when conversion is converted to wind energy conversion system balancing the load through Clarke _α, M _β;

Step 12: two vertical component M when wind energy conversion system balancing the load _α, M _βsignal is given the first ratio resonant controller, and output, corresponding to α, is expected propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _β,

Step 13: corresponding to α, expect propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _βthrough Clarke, inverse transformation obtains three blades propeller pitch angle increment size θ in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3, step 14: the propeller pitch angle increment size θ of three blades in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3during respectively with wind energy conversion system balancing the load, unify the setting value θ of propeller pitch angle _cbe added propeller pitch angle θ while exporting total wind energy conversion system balancing the load _c+ θ _b1, θ _c+ θ _b2, θ _c+ θ _b3give respectively the servo-system of three blades;

When wind energy conversion system is load unbalanced:

Step 21: by the bending moment M of three propeller shanks ₁, M ₂, M ₃give master controller with azimuth signal, obtain wind energy conversion system two vertical component M when load unbalanced through Coleman conversion _dand M _q;

Step 22: vertical component M when wind energy conversion system is load unbalanced _d, M _qsignal is given the second ratio resonant controller, and output, corresponding to d, is expected propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _q,

Step 23: corresponding to d, expect propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _qobtain the propeller pitch angle increment size θ of wind energy conversion system three blades when load unbalanced through Coleman inverse transformation _i1, θ _i2, θ _i3,

Step 24: the propeller pitch angle increment size θ of three blades when wind energy conversion system is load unbalanced _i1, θ _i2, θ _i3propeller pitch angle reference value during respectively with wind energy conversion system balance is added, total propeller pitch angle θ when output wind energy conversion system is load unbalanced _c+ θ _b1+ θ _i1, θ _c+ θ _b2+ θ _i2, θ _c+ θ _b3+ θ _i3give respectively the servo-system of three blades.

Preferably, in step 11, the bending moment M of three propeller shanks ₁, M ₂, M ₃two vertical component M when conversion is converted to wind energy conversion system balancing the load through Clarke _α, M _β, specifically realize by the following method:

$\left[\begin{array}{c}{M}_{\mathrm{\&alpha;}}\\ M_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

Preferably, the independent pitch control method of wind-power generating system, is characterized in that:

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="c\; s\; s"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">c</figure-callout>}}s}{s^{}}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hbe the resonance coefficient of the first ratio resonant controller, ω ₀for resonant frequency, ω _cin order to prevent G _pR(s) parameter of the too large introducing of gain; ω _c<< ω ₀, h=1,2,4; S is Laplace operator, G _pR(s) be the transfer function of the first ratio resonant controller.Step 13, corresponding to α, expects propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _βthrough Clarke, inverse transformation obtains three blades propeller pitch angle increment size θ in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3,

Realize by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right].$

Step 21, by the bending moment M of three propeller shanks ₁, M ₂, M ₃give master controller with azimuth signal, obtain wind energy conversion system two vertical component M when load unbalanced through Coleman conversion _dand M _q; Realize by the following method:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

Preferably, in step 22, the transfer function of the second ratio resonant controller is:

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{c}s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2{\mathrm{\&omega;}}_{c}s+{{\mathrm{\&omega;}}_0}^2}$

Wherein P _1pand K _1pbe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀for resonant frequency, ω _cin order to prevent G _pR1p(s) parameter of the too large introducing of gain, s is Laplace operator, G _pR1p(s) be the transfer function of the second ratio resonant controller.

Step 23, corresponding to d, expects propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _qobtain the propeller pitch angle increment size θ of wind energy conversion system three blades when load unbalanced through Coleman inverse transformation _i1, θ _i2, θ _i3, embody by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{i1}\\ {\mathrm{\&theta;}}_{i2}\\ {\mathrm{\&theta;}}_{i3}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\&omega;t}\right)& \sin \left(\mathrm{\&omega;t}\right)\\ \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})\\ \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_d\\ {\mathrm{\&theta;}}_q\end{array}\right].$

Technical conceive of the present invention is: on traditional unified basis that becomes oar control, several very little components that superpose on the propeller pitch angle of each blade are respectively used for eliminating the load of different frequency on wind energy conversion system.

Due to the impact of the factors such as wind shear, tower shadow effect, wind turbulent flow, the load on wind machine oar leaf has comprised 0p, 1p, 2p, 3p, 4p ... aliquot.By analysis, the pitch moment M of wind energy conversion system _tiltwith yawing moment M _yawto be caused by the load on blade.Blade upper frequency is 3i ω, i=0,1,2,3 ... load cancelled out each other while transferring on wind mill rotor wheel hub, when the load of other frequencies is transferred on rotor frequency become from the multiple of 3p recently.So rotor and other static parts will be born 3p, the equifrequent load of 6p.Such as, epitrochanterian 3p load is to be caused by the 2p on blade and 4p load, epitrochanterian 6p load is to be caused by the 5p on blade and 7p load.In the time that wind energy conversion system is uneven, wind mill rotor is except bearing 0p, 3p, and outside the load such as 6p, it also will bear the load of 1p, and the disequilibrium of wind energy conversion system is higher, and 1p component will be larger.

Therefore, the 1p load reducing on blade can effectively reduce the fatigue loading on blade, has reduced the 0p load on wind mill rotor simultaneously.But epitrochanterian fatigue loading is mainly to be caused by the 3p load on it, because epitrochanterian 3p causes by the 2p on blade and 4p, so can load to reduce epitrochanterian fatigue loading by the 2p and the 4p that reduce blade.Epitrochanterian 6p also can produce certain fatigue loading in addition, but very high because of its requirement of servo-system to propeller pitch angle, loads therefore generally do not consider to reduce 6p.

The concrete technical conceive of the independent pitch control method that therefore, this invention proposes is:

When wind energy conversion system balancing the load: the bending moment (M that detects three propeller shanks ₁, M ₂, M ₃) give master controller, master controller is by M ₁, M ₂, M ₃through Clarke, conversion is converted to two vertical component M _α, M _β.M _α, M _βsignal is given ratio resonant controller 1, exports corresponding to α the expectation propeller pitch angle θ of β axle _α, θ _β.θ _α, θ _βthrough Clarke, inverse transformation obtains the propeller pitch angle increment size θ of three blades _b1, θ _b2, θ _b3.θ _b1, θ _b2, θ _b3respectively with the setting value θ that unifies propeller pitch angle _cbe added, export total propeller pitch angle (θ _c+ θ _b1, θ _c+ θ _b2, θ _c+ θ _b3) servo-system of giving respectively three blades.

When wind energy conversion system is load unbalanced: by M ₁, M ₂, M ₃give master controller with azimuth signal, through Coleman, conversion obtains two vertical component M _dand M _q.M _d, M _qsignal is given ratio resonant controller 2, exports corresponding to d the expectation propeller pitch angle θ of q axle _d, θ _q.θ _d, θ _qthrough Coleman, inverse transformation obtains the propeller pitch angle increment size θ of three blades _i1, θ _i2, θ _i3.θ _i1, θ _i2, θ _i3propeller pitch angle reference value during respectively with wind energy conversion system balance is added, and exports total propeller pitch angle (θ _c+ θ _b1+ θ _i1, θ _c+ θ _b2+ θ _i2, θ _c+ θ _b3+ θ _i3) servo-system of giving respectively three blades.

Fig. 1 invents the independent feathering control schematic diagram of proposition for this reason.This control system has two Control loops, is used for respectively processing wind energy conversion system balancing the load and unbalanced situation.Under normal balance, only need balance load Control loop to eliminate the 1p on blade, the 0p of the load of 2p and 4p and wind energy conversion system standing part and 3p load; In the time blade uneven being detected, start uncompensated load control ring to eliminate its 1p fatigue load to wind mill rotor.This independent feathering control process comprises:

When wind energy conversion system balancing the load:

1) detect the bending moment (M of three propeller shanks ₁, M ₂, M ₃) give master controller, master controller is by M ₁, M ₂, M ₃through Clarke, conversion is converted to two vertical component M _α, M _β.Specifically can embody by following formula:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right]$

2) M _α, M _βsignal is given ratio resonant controller 1, exports corresponding to α the expectation propeller pitch angle θ of β axle _α, θ _β.This ratio resonant controller 1 transfer function specifically can embody by following formula:

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{c}s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2{\mathrm{\&omega;}}_{c}s+{\left(h{\mathrm{\&omega;}}_0\right)}^2}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hbe the resonance coefficient of the first ratio resonant controller, ω ₀for resonant frequency, ω _cin order to prevent G _pR(s) parameter of the too large introducing of gain; ω _c<< ω ₀, h=1,2,4; S is Laplace operator, G _pR(s) be the transfer function of the first ratio resonant controller.

3) θ _α, θ _βthrough Clarke, inverse transformation obtains the propeller pitch angle increment size θ of three blades _b1, θ _b2, θ _b3.Specifically can embody by following formula:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right]$

4) θ _b1, θ _b2, θ _b3respectively with the setting value θ that unifies propeller pitch angle _cbe added, export total propeller pitch angle (θ _c+ θ _b1, θ _c+ θ _b2, θ _c+ θ _b3) servo-system of giving respectively three blades.

When wind energy conversion system is load unbalanced, start uncompensated load control:

1) by M ₁, M ₂, M ₃give master controller with azimuth signal, through Coleman, conversion obtains two vertical component M _dand M _q.Specifically can embody by following formula:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

2) M _d, M _qsignal is given ratio resonant controller 2, exports corresponding to d the expectation propeller pitch angle θ of q axle _d, θ _q.These ratio resonant controller 2 transfer functions specifically can embody by following formula:

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{c}s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002388922200022.png,HDA00002388922200031.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2{\mathrm{\&omega;}}_{c}s+{{\mathrm{\&omega;}}_0}^2}$

Wherein P _1pand K _1pbe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀for resonant frequency, ω _cin order to prevent G _pR1p(s) parameter of the too large introducing of gain, s is Laplace operator, G _pR1p(s) be the transfer function of the second ratio resonant controller.

3) θ _d, θ _qthrough Coleman, inverse transformation obtains the propeller pitch angle increment size θ of three blades _i1, θ _i2, θ _i3.Specifically can embody by following formula:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{i1}\\ {\mathrm{\&theta;}}_{i2}\\ {\mathrm{\&theta;}}_{i3}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\&omega;t}\right)& \sin \left(\mathrm{\&omega;t}\right)\\ \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})\\ \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_d\\ {\mathrm{\&theta;}}_q\end{array}\right]$

4) θ _i1, θ _i2, θ _i3propeller pitch angle reference value during respectively with wind energy conversion system balance is added, and exports total propeller pitch angle (θ _c+ θ _b1+ θ _i1, θ _c+ θ _b2+ θ _i2, θ _c+ θ _b3+ θ _i3) servo-system of giving respectively three blades.System analysis figure when Fig. 2 is wind energy conversion system balancing the load to Fig. 5.

Fig. 2 is the spectrogram of propeller shank bending moment.On rated wind speed, the rotating speed of wind energy conversion system is 2.147rad/s, and the frequency of corresponding 1p is 0.342Hz.Become under oar control unified as seen from the figure, in the load of blade, contain a large amount of 1p, 2p, 3p, 4p etc., in order to reduce the main fatigue load 1p load on blade, with the main fatigue load 3p load reducing on wind energy conversion system wheel hub, by the independent feathering control proposing, the 1p on blade as seen from Figure 2,2p, the load of 4p has all obtained great minimizing.

Fig. 3 is pitch moment M _tiltspectrogram, Fig. 4 is yawing moment M _yawspectrogram.Can clearly find out, compare the unified oar control that becomes, under independent feathering control, M _tiltand M _yaw0p component very little, mean M _tiltand M _yawmean value all changed near 0 because the 1p on blade is the immediate cause that causes 0p on rotor hub.Because the 2p on blade and 4p have obtained reducing very greatly, M _tiltand M _yawin main fatigue load 3p obtained very big minimizing.

Fig. 5 is the propeller pitch angle of three blades.Become in oar control unified, the propeller pitch angle of three blades is identical, can not effectively reduce the load of wind energy conversion system.In independent feathering control, the propeller pitch angle of three blades can be adjusted in real time independently according to the load of wind energy conversion system, effectively reduces wind energy conversion system load.The speed of response that should be noted that propeller pitch angle servo-system is very crucial, and concerning servo-system, eliminating more high-frequency load needs faster speed of response, and in this invention, the pace of change of propeller pitch angle is within 10 °/s.

Can be absolutely proved to Fig. 5 by Fig. 2, the independent feathering control that this invention proposes can effectively reduce the load of wind energy conversion system in the situation that of wind energy conversion system balancing the load, increases the service life of wind energy conversion system.This controlling method is simple, is easy to carry out.

Fig. 6 is the system analysis figure of wind energy conversion system when load unbalanced to Fig. 7.

Fig. 6 and Fig. 7 are pitch moment M _tiltwith yawing moment M _yawspectrogram.Visible in the time that wind energy conversion system is load unbalanced, in the pitch moment of wind energy conversion system and yawing moment, contain the load of 1p, the independent pitch control method proposing by this invention can reduce this fatigue loading significantly.

The foregoing is only preferred embodiments of the present invention; protection scope of the present invention is not limited with above-mentioned mode of execution; in every case the equivalence that those of ordinary skills do according to disclosed content is modified or is changed, and all should include in the protection domain of recording in claims.

Claims (7)

1. the independent pitch control method of a wind-power generating system, it is characterized in that: the control system that this controlling method adopts comprises two Control loops, be balanced load Control loop and uncompensated load Control loop, be used for respectively processing wind energy conversion system balancing the load and unbalanced situation, under balance, balance load Control loop is eliminated load on blade and the load of wind energy conversion system standing part; In the time load uneven being detected, start uncompensated load Control loop to eliminate its fatigue load to wind energy conversion system wheel hub and standing part, the method comprises:

When wind energy conversion system balancing the load:

Step 11: the bending moment M that detects respectively three propeller shanks ₁, M ₂, M ₃give master controller, master controller is by the bending moment M of three propeller shanks ₁, M ₂, M ₃two vertical component M when conversion is converted to wind energy conversion system balancing the load through Clarke _α, M _β;

Step 12: two vertical component M when wind energy conversion system balancing the load _α, M _βsignal is given the first ratio resonant controller, and output, corresponding to α, is expected propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _β,

Step 13: corresponding to α, expect propeller pitch angle θ when the wind energy conversion system balancing the load of β axle _α, θ _βthrough Clarke, inverse transformation obtains three blades propeller pitch angle increment size θ in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3,

Step 14: the propeller pitch angle increment size θ of three blades in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3during respectively with wind energy conversion system balancing the load, unify the setting value θ of propeller pitch angle _cbe added propeller pitch angle θ while exporting total wind energy conversion system balancing the load _c+ θ _b1, θ _c+ θ _b2, θ _c+ θ _b3give respectively the servo-system of three blades;

When wind energy conversion system is load unbalanced:

Step 21: by the bending moment M of three propeller shanks ₁, M ₂, M ₃give master controller with azimuth signal, obtain wind energy conversion system two vertical component M when load unbalanced through Coleman conversion _dand M _q;

Step 22: vertical component M when wind energy conversion system is load unbalanced _d, M _qsignal is given the second ratio resonant controller, and output, corresponding to d, is expected propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _q,

Step 23: corresponding to d, expect propeller pitch angle θ when the wind energy conversion system of q axle is load unbalanced _d, θ _qobtain the propeller pitch angle increment size θ of wind energy conversion system three blades when load unbalanced through Coleman inverse transformation _i1, θ _i2, θ _i3,

Step 24: the propeller pitch angle increment size θ of three blades when wind energy conversion system is load unbalanced _i1, θ _i2, θ _i3propeller pitch angle reference value during respectively with wind energy conversion system balance is added, total propeller pitch angle θ when output wind energy conversion system is load unbalanced _c+ θ _b1+ θ _i1, θ _c+ θ _b2+ θ _i2, θ _c+ θ _b3+ θ _i3give respectively the servo-system of three blades.

2. the independent pitch control method of wind-power generating system according to claim 1, is characterized in that: in step 11, and the bending moment M of three propeller shanks ₁, M ₂, M ₃two vertical component M when conversion is converted to wind energy conversion system balancing the load through Clarke _α, M _β, specifically realize by the following method:

$\left[\begin{array}{c}{M}_{\mathrm{\&alpha;}}\\ M_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ M_3\end{array}\right].$

3. the independent pitch control method of wind-power generating system according to claim 1, is characterized in that:

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{c}s}{s^2+2{\mathrm{\&omega;}}_{c}s+{\left(h{\mathrm{\&omega;}}_0\right)}^2}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hbe the resonance coefficient of the first ratio resonant controller, ω ₀for resonant frequency, ω _cin order to prevent G _pR(s) the large parameter of introducing of gain; ω _c<< ω ₀, h=1,2,4; S is Laplace operator, G _pR(s) be the transfer function of the first ratio resonant controller.

4. the independent pitch control method of wind-power generating system according to claim 1, is characterized in that: step 13, corresponding to α, when the wind energy conversion system balancing the load of β axle, expect propeller pitch angle θ _α, θ _βthrough Clarke, inverse transformation obtains three blades propeller pitch angle increment size θ in the time of wind energy conversion system balancing the load _b1, θ _b2, θ _b3, realize by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{b1}\\ {\mathrm{\&theta;}}_{b2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right].$

5. the independent pitch control method of wind-power generating system according to claim 1, is characterized in that: step 21, and by the bending moment M of three propeller shanks ₁, M ₂, M ₃give master controller with azimuth signal, obtain wind energy conversion system two vertical component M when load unbalanced through Coleman conversion _dand M _q; Realize by the following method:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ M_3\end{array}\right].$

6. the independent pitch control method of wind-power generating system according to claim 1, is characterized in that: in step 22, the transfer function of the second ratio resonant controller is:

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{c}s}{s^2+2{\mathrm{\&omega;}}_{c}s+{{\mathrm{\&omega;}}_0}^2}$

Wherein P _1pand K _1pbe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀for resonant frequency, ω _cin order to prevent G _pR1p(s) the large parameter of introducing of gain, s is Laplace operator, G _pR1p(s) be the transfer function of the second ratio resonant controller.

7. the independent pitch control method of wind-power generating system according to claim 1, is characterized in that: step 23, corresponding to d, when the wind energy conversion system of q axle is load unbalanced, expect propeller pitch angle θ _d, θ _qobtain the propeller pitch angle increment size θ of wind energy conversion system three blades when load unbalanced through Coleman inverse transformation _i1, θ _i2, θ _i3, embody by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{i1}\\ {\mathrm{\&theta;}}_{i2}\\ {\mathrm{\&theta;}}_{i3}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\&omega;t}\right)& \sin \left(\mathrm{\&omega;t}\right)\\ \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})\\ \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_d\\ {\mathrm{\&theta;}}_q\end{array}\right].$

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