CN102926930A - 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 to the giving more sustained attention of energy crisis and environmental pollution problem, the renewable energy sources particularly development and use of wind-power electricity generation is just presenting the trend of accelerated development.Increase along with the 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 at 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 to adopt the unified oar control that becomes, and namely to overlap the propeller pitch angle of three blades of blade pitch device control independently identical by controlling three, thereby reduce catching of wind energy, so that wind-powered electricity generation unit amount of exports is decided power.But this unified load, particularly fatigue loading that wind energy conversion system is not considered in oar control that become, along with the increase of wind energy conversion system capacity, the problem of load more and more obviously and need to be resolved hurrily.

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

The main policies of the independent feathering control that before proposes both at home and abroad is to detect the bending moment M of three propeller shanks ₁, M ₂, M ₃The Coleman conversion is passed through afterwards with M in the azimythal angle (azimuth angle) of (blade root bending moment) and rotor ₁, M ₂, M ₃Be transformed to pitch moment M _TiltWith yawing moment M _YawIn order to reduce the impact of other higher harmonicss, usually at M _TiltAnd M _YawAdd two low-pass filters (LPF) after the signal, afterwards by the propeller pitch angle θ of controller (PI, LQG etc.) output corresponding to pitch moment and yawing moment _TiltAnd θ _Yaw, through the increment θ of three blade angles of Coleman inverse transformation output expectation _B1, θ _B2, θ _B3θ _B1, θ _B2, θ _B3Give respectively the servo-system of three blades with the total propeller pitch angle of the unified propeller pitch angle addition output that becomes oar output respectively again, thereby reduce 1p load on the blade and the 0p on the wheel hub loads.If wish to eliminate the fatigue loading of wind energy conversion system wheel hub and standing part, then need to load by 2p and 4p that similar control strategy is eliminated respectively on the blade.This shows that 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 a plurality of low-pass filters and a plurality of controller, the control system very complex.

In addition, the independent feathering control technology overwhelming majority who proposes does not both at home and abroad consider the situation that wind energy conversion system is load unbalanced, yet in the process of wind energy conversion system operation, the quality of blade may change, perhaps blade damages to some extent, and perhaps blade can freeze etc. in the low situation of temperature, 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 the 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 cost, 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 the blade and the load of wind energy conversion system standing part; When detecting load uneven, start the uncompensated load Control loop to eliminate it to the fatigue load of wind energy conversion system wheel hub and standing part, the method comprises:

During the 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 with the bending moment M of three propeller shanks ₁, M ₂, M ₃Two vertical component M when conversion is converted to the wind energy conversion system balancing the load through Clarke _α, M _β

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

Step 13: corresponding to α, expectation propeller pitch angle θ during the wind energy conversion system balancing the load of β axle _α, θ _βInverse transformation obtains three blades propeller pitch angle increment size θ when the wind energy conversion system balancing the load through Clarke _B1, θ _B2, θ _B3,

Step 14: the propeller pitch angle increment size θ of three blades when the wind energy conversion system balancing the load _B1, θ _B2, θ _B3The setting value θ that unifies propeller pitch angle during respectively with the wind energy conversion system balancing the load _cAddition, propeller pitch angle θ when 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: with 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 the 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 is expected propeller pitch angle θ corresponding to d when the wind energy conversion system of q axle is load unbalanced _d, θ _q,

Step 23: corresponding to d, expectation 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 the 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 addition during respectively with the wind energy conversion system balance, output wind energy conversion system total propeller pitch angle θ when 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 the step 11, the bending moment M of three propeller shanks ₁, M ₂, M ₃Two vertical component M when conversion is converted to the wind energy conversion system balancing the load through Clarke _α, M _β, specifically realize by the following method:

$\left[\begin{array}{c}{M}_{\mathrm{\&alpha;}}\\ M_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200011.png,HDA00002388922200021.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

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

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="c\; s\; s"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">c</figure-callout>}}s}{s^{}}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hBe the resonance coefficient of the first ratio resonant controller, ω ₀Be 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, expectation propeller pitch angle θ during the wind energy conversion system balancing the load of β axle _α, θ _βInverse transformation obtains three blades propeller pitch angle increment size θ when the wind energy conversion system balancing the load through Clarke _B1, θ _B2, θ _B3,

Realize by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200041.png,HDA00002388922200042.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="3"\; label="b"\; filenames="HDA00002388922200011.png,HDA00002388922200021.png"\; state="\{\{state\}\}">b</figure-callout>}3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right].$

Preferably, step 21 is with 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 the Coleman conversion _dAnd M _qRealize by the following method:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200011.png,HDA00002388922200021.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

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

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="c\; s\; s"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">c</figure-callout>}}s}{s^{}}$

P wherein _1pAnd K _1pBe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀Be 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, expectation 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 the 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 when the wind energy conversion system balance, save the azimuthal detection of wind energy conversion system, saved the repeatedly rotation of complexity and the transformation of coordinates between the rest frame, the use of having saved simultaneously some low-pass filters.This control strategy can reduce 1p on the 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.When wind energy conversion system was uneven, this independent feathering control strategy had 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 the reliability high can effectively prolong working life of wind energy conversion system.

Description of drawings

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 representation of independent feathering control;

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

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

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 can reduce by corresponding control strategy the load of wind energy conversion system when wind energy conversion system balancing the load and imbalance.When the wind energy conversion system balancing the load, compare with traditional independent feathering control strategy, this independent feathering control strategy can save the azimuthal detection of wind energy conversion system and repeatedly complicated rotation and the transformation of coordinates between the rest frame, has saved simultaneously some low-pass filters.This control strategy can reduce 1p on the blade, and the load of 2p and above high secondary frequencies reduces the 3p load on the wind energy conversion system wheel hub simultaneously.When wind energy conversion system was load unbalanced, this independent feathering control strategy had added the control of uncompensated load outside balanced load control, can effectively reduce the 1p load on the standing part such as wind energy conversion system wheel hub.This independent feathering control can reduce the fatigue load of wind energy conversion system effectively, prolongs its service life.

The independent pitch control method of wind-power generating system provided by the invention, the control system that 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 the blade and the load of wind energy conversion system standing part; When detecting load uneven, start the uncompensated load Control loop to eliminate it to the fatigue load of wind energy conversion system wheel hub and standing part, the method comprises:

During the 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 with the bending moment M of three propeller shanks ₁, M ₂, M ₃Two vertical component M when conversion is converted to the wind energy conversion system balancing the load through Clarke _α, M _β

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

Step 13: corresponding to α, expectation propeller pitch angle θ during the wind energy conversion system balancing the load of β axle _α, θ _βInverse transformation obtains three blades propeller pitch angle increment size θ when the wind energy conversion system balancing the load through Clarke _B1, θ _B2, θ _B3, step 14: the propeller pitch angle increment size θ of three blades when the wind energy conversion system balancing the load _B1, θ _B2, θ _B3The setting value θ that unifies propeller pitch angle during respectively with the wind energy conversion system balancing the load _cAddition, propeller pitch angle θ when 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: with 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 the 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 is expected propeller pitch angle θ corresponding to d when the wind energy conversion system of q axle is load unbalanced _d, θ _q,

Step 23: corresponding to d, expectation 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 the 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 addition during respectively with the wind energy conversion system balance, output wind energy conversion system total propeller pitch angle θ when 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 the step 11, the bending moment M of three propeller shanks ₁, M ₂, M ₃Two vertical component M when conversion is converted to the wind energy conversion system balancing the load through Clarke _α, M _β, specifically realize by the following method:

$\left[\begin{array}{c}{M}_{\mathrm{\&alpha;}}\\ M_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200011.png,HDA00002388922200021.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

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

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="c\; s\; s"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">c</figure-callout>}}s}{s^{}}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hBe the resonance coefficient of the first ratio resonant controller, ω ₀Be 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, expectation propeller pitch angle θ during the wind energy conversion system balancing the load of β axle _α, θ _βInverse transformation obtains three blades propeller pitch angle increment size θ when the wind energy conversion system balancing the load through Clarke _B1, θ _B2, θ _B3,

Realize by the following method:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200041.png,HDA00002388922200042.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right].$

Step 21 is with 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 the Coleman conversion _dAnd M _qRealize by the following method:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200011.png,HDA00002388922200021.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

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

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{c}s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2{\mathrm{\&omega;}}_{c}s+{{\mathrm{\&omega;}}_0}^2}$

P wherein _1pAnd K _1pBe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀Be 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, expectation 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 the 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 the basis of traditional unified change oar control, be used for eliminating respectively the load of different frequency on the wind energy conversion system at the several very little components of propeller pitch angle stack of each blade.

Because the impact of the factors such as wind shear, tower shadow effect, wind turbulent flow, the load on the 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 the blade.The blade upper frequency is 3i ω, i=0,1,2,3 ... load cancelled out each other when transferring on the wind mill rotor wheel hub, when the load of other frequencies is transferred on the 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 the blade and 4p load, epitrochanterian 6p load is to be caused by the 5p on the blade and 7p load.When wind energy conversion system was uneven, wind mill rotor was 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 the 1p component will be larger.

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

Therefore, the concrete technical conceive of the independent pitch control method of this invention proposition is:

During the 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 with M ₁, M ₂, M ₃Conversion is converted to two vertical component M through Clarke _α, M _βM _α, M _βSignal is given ratio resonant controller 1, exports corresponding to α the expectation propeller pitch angle θ of β axle _α, θ _βθ _α, θ _βInverse transformation obtains the propeller pitch angle increment size θ of three blades through Clarke _B1, θ _B2, θ _B3θ _B1, θ _B2, θ _B3Respectively with the setting value θ that unifies propeller pitch angle _cTotal propeller pitch angle (θ is exported in addition _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: with M ₁, M ₂, M ₃Give master controller with azimuth signal, conversion obtains two vertical component M through Coleman _dAnd M _qM _d, M _qSignal is given ratio resonant controller 2, exports corresponding to d the expectation propeller pitch angle θ of q axle _d, θ _qθ _d, θ _qInverse transformation obtains the propeller pitch angle increment size θ of three blades through Coleman _I1, θ _I2, θ _I3θ _I1, θ _I2, θ _I3Total propeller pitch angle (θ is exported in propeller pitch angle reference value addition during respectively with the wind energy conversion system balance _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 1p on the blade, the 0p of the load of 2p and 4p and wind energy conversion system standing part and 3p load; When detecting blade uneven, start the uncompensated load control ring to eliminate it to the 1p fatigue load of wind mill rotor.This independent feathering control process comprises:

During the wind energy conversion system balancing the load:

1) detects the bending moment (M of three propeller shanks ₁, M ₂, M ₃) give master controller, master controller is with M ₁, M ₂, M ₃Conversion is converted to two vertical component M through Clarke _α, M _βSpecifically can embody by following formula:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200041.png,HDA00002388922200042.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right]$

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 _βThis ratio resonant controller 1 transfer function specifically can embody by following formula:

$G_{\mathrm{PR}}\left(s\right)=P+\underset{h=\mathrm{1,2,4}}{\mathrm{\&Sigma;}}\frac{K_h{\mathrm{\&omega;}}_{c}s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2{\mathrm{\&omega;}}_{c}s+{\left(h{\mathrm{\&omega;}}_0\right)}^2}$

Wherein P is the scaling factor of the first ratio resonant controller, K _hBe the resonance coefficient of the first ratio resonant controller, ω ₀Be 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 _βInverse transformation obtains the propeller pitch angle increment size θ of three blades through Clarke _B1, θ _B2, θ _B3Specifically can embody by following formula:

$\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA00002388922200041.png,HDA00002388922200042.png"\; state="\{\{state\}\}">b</figure-callout>}1}\\ {\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">b</figure-callout>}2}\\ {\mathrm{\&theta;}}_{b3}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&theta;}}_{\mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_{\mathrm{\&beta;}}\end{array}\right]$

4) θ _B1, θ _B2, θ _B3Respectively with the setting value θ that unifies propeller pitch angle _cTotal propeller pitch angle (θ is exported in addition _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) with M ₁, M ₂, M ₃Give master controller with azimuth signal, conversion obtains two vertical component M through Coleman _dAnd M _qSpecifically can embody by following formula:

$\left[\begin{array}{c}{M}_d\\ M_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos \left(\mathrm{\&omega;t}\right)& \cos (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\\ \sin \left(\mathrm{\&omega;t}\right)& \sin (\mathrm{\&omega;t}+\frac{2\mathrm{\&pi;}}{3})& \sin (\mathrm{\&omega;t}+\frac{4\mathrm{\&pi;}}{3})\end{array}\right]\left[\begin{array}{c}{M}_1\\ M_2\\ {\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA00002388922200011.png,HDA00002388922200021.png"\; state="\{\{state\}\}">M</figure-callout>}}_3\end{array}\right].$

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 _qThese ratio resonant controller 2 transfer functions specifically can embody by following formula:

$G_{\mathrm{PR}1p}\left(s\right)=P_{1p}+\frac{K_{1p}{\mathrm{\&omega;}}_{c}s}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002388922200021.png,HDA00002388922200022.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+2{\mathrm{\&omega;}}_{c}s+{{\mathrm{\&omega;}}_0}^2}$

P wherein _1pAnd K _1pBe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀Be 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 _qInverse transformation obtains the propeller pitch angle increment size θ of three blades through Coleman _I1, θ _I2, θ _I3Specifically 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 _I3Total propeller pitch angle (θ is exported in propeller pitch angle reference value addition during respectively with the wind energy conversion system balance _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 the 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 the oar control unified as seen from the figure, contain a large amount of 1p in the load of blade, 2p, 3p, 4p etc., in order to reduce the main fatigue load 1p load on the blade, with the main fatigue load 3p load that reduces on the wind energy conversion system wheel hub, by the independent feathering control that proposes, the as seen from Figure 2 1p on the blade, 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 _YawThe 0p component very little, mean M _TiltAnd M _YawMean value all changed near 0 because the 1p on the blade is the immediate cause that causes 0p on the rotor hub.Because 2p and 4p on the blade have obtained very large reducing, M _TiltAnd M _YawIn main fatigue load 3p obtained very big minimizing.

Fig. 5 is the propeller pitch angle of three blades.Become in the 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 the wind energy conversion system load.The speed of response that should be noted that the propeller pitch angle servo-system is very crucial, and concerning servo-system, eliminating more high-frequency load then needs faster speed of response, and in this invention, the pace of change of propeller pitch angle is within 10 °/s.

Can be proved absolutely to Fig. 5 that by Fig. 2 the independent feathering control that this invention proposes can reduce the load of wind energy conversion system effectively in the situation of wind energy conversion system balancing the load, increase 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.As seen when wind energy conversion system is load unbalanced, contain the load of 1p in the pitch moment of wind energy conversion system and the yawing moment, the independent pitch control method that proposes by this invention can reduce this fatigue loading significantly.

The above only is preferred embodiments of the present invention; protection scope of the present invention is not limited with above-mentioned mode of execution; as long as the equivalence that those of ordinary skills do according to disclosed content is modified or changed, all should include in the protection domain of putting down in writing 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 the blade and the load of wind energy conversion system standing part; When detecting load uneven, start the uncompensated load Control loop to eliminate it to the fatigue load of wind energy conversion system wheel hub and standing part, the method comprises:

During the 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 with the bending moment M of three propeller shanks ₁, M ₂, M ₃Two vertical component M when conversion is converted to the wind energy conversion system balancing the load through clarks _α, M _β

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

Step 13: corresponding to α, expectation propeller pitch angle θ during the wind energy conversion system balancing the load of β axle _α, θ _βInverse transformation obtains three blades propeller pitch angle increment size θ when the wind energy conversion system balancing the load through clarks _B1, θ _B2, θ _B3,

Step 14: the propeller pitch angle increment size θ of three blades when the wind energy conversion system balancing the load _B1, θ _B2, θ _B3The setting value θ that unifies propeller pitch angle during respectively with the wind energy conversion system balancing the load _cAddition, propeller pitch angle θ when 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: with 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 the Kalman 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 is expected propeller pitch angle θ corresponding to d when the wind energy conversion system of q axle is load unbalanced _d, θ _q,

Step 23: corresponding to d, expectation 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 the Kalman 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 addition during respectively with the wind energy conversion system balance, output wind energy conversion system total propeller pitch angle θ when 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 the step 11, and the bending moment M of three propeller shanks ₁, M ₂, M ₃Two vertical component M when conversion is converted to the wind energy conversion system balancing the load through clarks _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 ₀Be 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, and corresponding to α, expectation propeller pitch angle θ during the wind energy conversion system balancing the load of β axle _α, θ _βInverse transformation obtains three blades propeller pitch angle increment size θ when the wind energy conversion system balancing the load through clarks _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 with 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 the Kalman conversion _dAnd M _qRealize 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, it is characterized in that: in the step 22, the transfer function of the second ratio resonant controller is:

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

P wherein _1pAnd K _1pBe respectively ratio and the resonance coefficient of the second ratio resonant controller; ω ₀Be 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, and corresponding to d, expectation 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 the Kalman 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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