CN104832368A - Concentrated wind energy type wind turbine set variable-pitch control method based on power multiplication characteristic - Google Patents

Abstract

The invention belongs to the technical field of wind power generation and particularly relates to a concentrated wind energy type wind turbine set variable-pitch control method based on a power multiplication characteristic. According to the control method, through research on a traditional concentrated wind energy type wind turbine set structure and a power characteristic, a subsection power tracking type fuzzy-PID variable-pitch control strategy is put forward. Through adoption of the basic theory and method of fuzzy mathematics, regular conditions and operation are represented through a fuzzy set and stored in a computer knowledge base as knowledge, best setting of PID parameters is realized automatically by using fuzzy reasoning by a computer according to actual response conditions of a control system, the power change characteristic of a concentrated wind energy type wind turbine set is fully considered by subsection fuzzy control, and the working condition of the turbine set is controlled section by section, so that the non-linearization degree of a controlled object in each section is reduced, meanwhile, setting of parameters Kp, Ki and Kd is simplified and the advantages of simple structure, good stability, high working reliability and high convenience in adjustment are fully developed.

Description

Based on the concentarted wind energy Wind turbines variable pitch control method of PD characteristic

Technical field

The invention belongs to technical field of wind power generation, particularly relate to a kind of concentarted wind energy Wind turbines variable pitch control method based on PD characteristic.

Background technique

The theoretical foundation of concentarted wind energy Wind turbines is that concentrated wind energy is theoretical.The core of concentrated wind energy theory is law of conservation of energy, by thin wind energy through the acceleration of concentrated wind energy device, rectification and the generating of homogenization rear driving vane rotary, thus improve the energy flux density of wind energy, improve the unstability of wind energy, improve wind energy grade.Concentarted wind energy Wind turbines relies on its congenital advantage, can be widely used in various wind speed, various air density area.

Concentarted wind energy Wind turbines has the n of its uniqueness ³power characteristic.High wind speed is interval, and the wind chugging rate acted on concentarted wind energy Wind turbines wind wheel is excessive, and conventional feather speed can not follow the tracks of wind changed power.Thus, a kind of special variable pitch control method is needed.

And under conventional variable pitch control strategy, feather speed is not all higher than 6 °/s, directly apply to the problem that can not solve power tracking on concentarted wind energy Wind turbines, more system destabilizing factor can be brought on the contrary, and rigid raising feather speed can cause system unstability.

It is simple that PID controls to have control principle, the advantages such as easy to use, strong adaptability, strong robustness, antijamming capability are strong, but due to conventional PID parameters setting method numerous and diverse, its parameter is often not easily adjusted and is caused poor performance.

When system mathematic model unknown or uncertain time, particularly for control system of wind turbines---non-linear, multi-variable system, fuzzy control can reach gratifying effect.

Summary of the invention

The technological deficiency that the fix pitch HAWT control mode adopted to solve current above-mentioned concentarted wind energy Wind turbines exists, by the analysis and research to the special wind power characteristic of concentarted wind energy Wind turbines, the present invention proposes a kind of concentarted wind energy Wind turbines variable pitch control method based on PD characteristic, comprising:

Step 1, according to different wind speed; concentarted wind energy Wind turbines operating mode is divided into six stages: treat the wind stage, power rises to the stage, power buffer stage, rated power stablize the output stage, cut out stage, feathering stoppage protection stage in advance; wherein front double teacher corresponding following wind speed interval respectively: [0, V _cut-in), [V _cut-in, V _95%ref), [V _95%ref, V _105%ref), [V _105%ref, V _180%ref), [V _180%ref, V _cut-out), wherein, V _cut-infor incision wind speed, V _95%refbe the rated wind speed of 95%, V _105%refbe the rated wind speed of 105%, V _180%refbe the rated wind speed of 180%, V _cut-outfor cut-out wind speed;

Step 2, when wind speed was in until the wind stage, the blade working of concentarted wind energy Wind turbines is under zero propeller pitch angle state, and variable-pitch control system is standby, and wind treated by complete machine;

Step 3, when wind speed be in power rise to the stage time, under the state that the blade working of concentarted wind energy Wind turbines is zero at propeller pitch angle, and carry out power tracking monitoring;

Step 4, when wind speed is in power buffer stage, power buffer stage is divided into buffering Interval I [V _95%ref, V _ref) and buffer area between II [V _ref, V _105%ref), thus between two buffer areas on carry out the linearization that is similar to, choose different domains, use different fuzzy control rules to carry out subsection fuzzy PID control; V _reffor rated wind speed;

Step 5, when wind speed be in rated power stablize the output stage time, rated power being stablized the output stage is divided into specified Interval I [V _105%ref, V _150%ref) and specified interval II [V _150%ref, V _180%ref), thus choose different domains in two specified intervals, use different fuzzy control rules, to reduce error, carry out subsection fuzzy PID control, V _150%refit is the rated wind speed of 180%;

Step 6, when wind speed be in cut out the stage in advance time, the aerodynamic brake characteristic of blade, rotating speed are joined in control strategy and carry out fuzzy-adaptation PID control; When wind speed exceeds threshold value in this stage, then directly feathering is shut down, and enters into the feathering stoppage protection stage;

Step 7, be in [V when wind speed _cut-out,+∞) interval time, blade is adjusted to full feathering state rapidly by variable-pitch control system; Stoppage protection aerogenerator unit safe.

Described subsection fuzzy PID control method comprises independently fuzzy tuning K _p, K _i, K _dlink, PID controlling unit, Error Feedback link, concrete steps are as follows:

Step 101, respectively with wind speed V, power P, power variation rate PC for coordinate axes, the word set choosing linguistic variable is { NB, NM, NS, ZR, PS, PM, PB}, i.e. { negative large, in negative, negative little, zero, just little, center, honest };

Step 102, application wind speed, power, power variation rate membership function determine word variable generation three-dimensional system of coordinate V, P, PC}, each coordinate axes of this three-dimensional system of coordinate has independently unit scaling;

Step 103, adjusting by the fringe to wind speed, power, power variation rate, and a unique corresponding coordinate points, by all coordinate points (V, P, PC) of adjusting as independent variable territory, act on PID controlled variable K _p, K _i, K _dfunction of adjusting;

Step 104, set the error of output power as E, error be changed to EC, propeller pitch angle be changed to U, the word set choosing the linguistic variable of E, EC, U is { NB, NM, NS, ZR, PS, PM, PB}, i.e. { negative large, in negative, negative little, zero, just little, center, honest };

Step 105, be givenly input as step signal, select following domain and relevant membership function thus, the fuzzy set of getting input E and EC for NB, NM, NS, ZR, PS, PM, PB}, domain is e={-30,30}, ec={-60,60}; In like manner, output K is got _pdomain be {-0.3,0.3}; Get and export K _idomain be {-0.06,0.06}; Get and export K _ddomain be {-3,3}.

Described PID controlled variable K _p, K _i, K _dfunction expression of adjusting be:

$\left[\begin{array}{c}{K}_p\\ K_i\\ K_d\end{array}\right]=\left[\begin{array}{c}{K}_p^{\′}(V,P,\mathrm{PC})\\ K_i^{\′}(V,P,\mathrm{PC})\\ K_d^{\′}(V,P,\mathrm{PC})\end{array}\right]+\left[\begin{array}{c}{\mathrm{\Δ}}_p\\ {\mathrm{\Δ}}_i\\ {\mathrm{\Δ}}_d\end{array}\right]$

K ' in formula _p(V, P, PC), K ' _i(V, P, PC), K ' _d(V, P, PC) is fuzzy-adaptation PID control variable transitions function respectively, Δ _p, Δ _i, Δ _dit is controlled quentity controlled variable error minus feedback.

Beneficial effect of the present invention is:

1, the present invention is by the tracking to power, carries out subsection fuzzy PID variable pitch control in different wind speed sections to concentarted wind energy Wind turbines, improves the precision controlled, guarantees that concentrated type Wind turbines is at different wind speed Duan Junneng optimized running.

2, the present invention has played the advantage of concentarted wind energy Wind turbines effectively, can significantly improve the cut-out wind speed of concentarted wind energy Wind turbines, reduces and abandons wind.Under large wind speed operating mode, in the process that wind energy increases suddenly, can be " partly cutting out " wind speed interval by the wind speed area definition between the cut-out wind speed of traditional 25m/s to the new cut-out wind speed defined, reduce the cost of generating, improve the economic benefit of unit, ensure that the safety grid-connection of Wind turbines runs.

3, the invention enables the research and development of concentarted wind energy Wind turbines large scale computer to become possibility, making to build Large Scale Wind Farm Integration with concentarted wind energy Wind turbines for unit becomes possibility, and will greatly reduce the cost per unit of wind-powered electricity generation, economic benefit, social benefit are rich.

4, feather fuzzy PID control strategy can suppress Security and the stability of the operation adding unit.Thus also reduce the maintenance, repair cost of unit.

Accompanying drawing explanation

Fig. 1 is the structural drawing of fuzzy-adaptation PID control in the present invention.

Fig. 2 is the flow chart of fuzzy-adaptation PID control in the present invention.

The wind conditions of Fig. 3 tri-kinds of states.

The power situation of Fig. 4 tri-kinds of states.

The propeller pitch angle situation of Fig. 5 tri-kinds of states.

The change oar rate behavior of Fig. 6 tri-kinds of states.

The blade root place of the blade 1 of Fig. 7 tri-kinds of states becomes oar moment of flexure.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment is elaborated.

The technological deficiency that the fix pitch HAWT control mode that the object of the invention is to adopt to solve current above-mentioned concentarted wind energy Wind turbines exists, by the analysis and research to the special wind power characteristic of concentarted wind energy Wind turbines, provide a kind of variable pitch control strategy adapting to the special power characteristic of concentarted wind energy Wind turbines.

Within the unit time, flow through the wind energy that wind wheel absorbs is:

$P=\frac{1}{2}{C}_p{\mathrm{AmV}}^2=\frac{1}{2}{C}_p\mathrm{A\ρV}\·V^2=\frac{1}{2}{C}_p\mathrm{A\ρ}{V}^3$ (formula 1)

P in formula---flow through in the unit time wind energy that wind wheel absorbs, w;

P '---air, through concentrated wind energy device, flows through in the unit time wind energy that wind wheel absorbs, w;

M---air flows through the quality of unit area within the unit time, kg;

ρ---air density, kg/m ³

V---wind speed, m/s

C _p---power coefficient

A---swept area of rotor

When air is after concentrated wind energy device, V becomes greatly original n times, now by formula 1, can obtain:

$P^{,}=\frac{1}{2}{C}_p\mathrm{A\ρ}{\left(\mathrm{nV}\right)}^3=n^3\frac{1}{2}{C}_p\mathrm{A\ρ}{V}^3=n^{3}P$ (formula 2)

It can thus be appreciated that concentrated by the wind energy of concentarted wind energy blower fan generator set, the flow velocity of average natural wind can increase to original n doubly, and output power can be n times of plain edition wind-driven generator.And decline through the turbulivity of natural wind, obviously increase from low wind speed section to the range of decrease of high wind speed section.This can show, output power can make greatly under same nominal power, and the high-speed rotary part of concentarted wind energy Wind turbines, the diameter of impeller are less than plain edition wind power generator impeller diameter, and weight is lighter, inertia is less, for variable pitch control brings certain convenience.

Due to the power characteristic of concentarted wind energy Wind turbines uniqueness, unit wind speed changes the n that the changed power brought is plain edition Wind turbines changed power ³doubly, too high in chugging rate, for the accuracy of variable pitch control, real-time all bring great difficulty.

In Wind turbines variable pitch control, K _p, K _i, K _dparameter is not easily adjusted makes PID control accuracy, stability is subject to great impact.And the changed power of concentarted wind energy Wind turbines is exceedingly fast, classical PID controls as easy as rolling off a log because arithmetic speed is excessively slow, the unreasonable power that causes of parameter tuning controls not in time, causes burning machine.Parameter tuning we use basic theories and the method for fuzzy mathematics, the condition of rule, operation fuzzy set are represented, and using these fuzzy control rules and for information about as knowledge stored in computer literacy storehouse, then computer is according to the real response situation of control system, use fuzzy reasoning, automatic realization the best to pid parameter is adjusted, Here it is fuzzy-adaptation PID control.

First carry out describing to segmented power tracking type fuzzy-adaptation PID control principle.

The power characteristic of concentarted wind energy Wind turbines, has larger difference with plain edition Wind turbines.Due to the effect of concentrated wind energy device, natural wind speed will be accelerated n doubly, and from formula 2, wind energy by become original doubly.This just means, concentarted wind energy Wind turbines in the dynamic load that will overcome under common Wind turbines declared working condition of low wind speed section; When concentarted wind energy Wind turbines works in rated wind speed, blower fan will overcome the dynamic load of common blower fan high wind speed section; And Concentrated Wind Energy Turbine is when working in high wind speed section close to plain edition wind-driven generator cut-out wind speed, plain edition Wind turbines closes oar already shuts down to ensure security of system, but concentarted wind energy Wind turbines still needs continuous firing.This just makes to seem particularly important to the operating mode segmentation of concentarted wind energy Wind turbines and the control response of high wind speed section.

Among concentarted wind energy Wind turbines segmented power tracking type fuzzy variable pitch control strategy, it is a core idea that segmented power follows the tracks of fuzzy-adaptation PID control.By segmentation, whole control interval is divided into some operation intervals with relative general character.Concentarted wind energy Wind turbines has unique power characteristic, whole operation interval is divided into the nonlinear degree that several operation intervals are conducive to weakening each interval.Avoid applying unified fuzzy control rule on whole strong nonlinearity operation interval, cause the decline of control accuracy.

(1) concentration-type Wind turbines operating mode divides

1) the wind stage is treated

Treat that wind stage definitions is [0, V _cut-in).In this stage, the blade working of concentarted wind energy Wind turbines is under zero propeller pitch angle state, and variable-pitch control system is standby, and wind treated by complete machine.This stage is without fuzzy-adaptation PID control.

2) power rises to the stage

Power rises to stage definitions for [V _cut-in, V _95%ref).In this stage, under the state that the blade working of concentarted wind energy Wind turbines is zero at propeller pitch angle.In this stage without fuzzy-adaptation PID control, only carry out power tracking monitoring.

3) power buffer stage

Power buffer stage is defined as buffering Interval I [V _95%ref, V _ref) and buffer area between II [V _ref, V _105%ref).

According to derivation:

$\begin{array}{c}{\mathrm{\ΔP}}_{\mathrm{HI}}=(P_{\mathrm{ref}}-P_{95\%\mathrm{ref}})/5\\ =[n^3\frac{1}{2}\mathrm{\ρ}{V_{\mathrm{ref}}}^3-n^3\frac{1}{2}\mathrm{\ρ}{\left(0.95V_{\mathrm{ref}}\right)}^3]/5\≈{0.014n}^3\mathrm{\ρ}{V_{\mathrm{ref}}}^3\end{array}$ (formula 3)

$\begin{array}{c}{\mathrm{\ΔP}}_{\mathrm{HII}}=(P_{105\%\mathrm{ref}}-P_{\mathrm{ref}})/5\\ =[n^3\frac{1}{2}\mathrm{\ρ}{\left(1.05V_{\mathrm{ref}}\right)}^3-n^3\frac{1}{2}\mathrm{\ρ}{V_{\mathrm{ref}}}^3]/5\≈{0.016n}^3\mathrm{\ρ}{V_{\mathrm{ref}}}^3\end{array}$ (formula 4)

Known, in order to avoid the power oscillation that plain edition blower fan causes near rated power, herein buffer stage is divided into buffering Interval I [V _95%ref, V _ref) and buffer area between II [V _ref, V _105%ref), thus between two buffer areas on carry out the linearization that is similar to, choose different domains, use different fuzzy control rules to carry out subsection fuzzy PID control.This structural design can smooth power, avoids power oscillation, protection unit.

And this fuzzy-adaptation PID control needs to be based upon on the basis of the monitoring of unit electromotive power output, wind speed, generator speed and propeller pitch angle.

4) rated power stablizes the output stage

Rated power stable output stage definitions is specified Interval I [V _105%ref, V _150%ref) and specified interval II [V _150%ref, V _180%ref).Unit is at [V _105%ref, V _180%ref) interval presents strong nonlinear characteristic, fuzzy-adaptation PID control is carried out in this interval, chooses unified control law and will have a strong impact on the accuracy of system.

As calculated:

$\begin{array}{c}{\mathrm{\ΔP}}_{\mathrm{WI}}=(P_{150\%\mathrm{ref}}-P_{105\%\mathrm{ref}})/45\\ =[n^3\frac{1}{2}\mathrm{\ρ}{\left(1.5V_{\mathrm{ref}}\right)}^3-n^3\frac{1}{2}\mathrm{\ρ}{\left(1.05V_{\mathrm{ref}}\right)}^3]/45\≈{0.025n}^3\mathrm{\ρ}{V_{\mathrm{ref}}}^3\end{array}$ (formula 5)

$\begin{array}{c}{\mathrm{\ΔP}}_{\mathrm{WII}}=(P_{180\%\mathrm{ref}}-P_{150\%\mathrm{ref}})/30\\ =[n^3\frac{1}{2}\mathrm{\ρ}{(1.8V_{\mathrm{ref}})}^3-n^3\frac{1}{2}\mathrm{\ρ}{\left(1.5V_{\mathrm{ref}}\right)}^3]/30\≈{0.041n}^3\mathrm{\ρ}{V_{\mathrm{ref}}}^3\end{array}$ (formula 6)

Known, needing rated power to stablize the output stage is divided into specified Interval I [V _105%ref, V _150%ref) and specified interval II [V _150%ref, V _180%ref), thus choose different domains in two specified intervals, use different fuzzy control rules, to reduce error, carry out subsection fuzzy PID control.While avoiding overshoot, the unit that the undermodulation also avoided causes damages, and plays the function of system protection.Finally reach stable power tracking, realize maximal wind-energy capture.

5) stage " is cut out " in advance

" cut out " stage definitions in advance for interval [V _180%ref, V _cut-out).Due to the 1-n of concentration-type Wind turbines ³power characteristic.In this stage, concentarted wind energy running of wind generating set is under reduced power state.Now wind power is very violent with wind speed change, and even when cut-out wind speed, the wind speed acted on blade is equivalent to act on the extreme wind speeds on the common blower fan of part.Now the propeller pitch angle of the blade of Wind turbines only to work under large propeller pitch angle state just can smooth working in this stage.This stage running is under reduced power state, and under concentarted wind energy Wind turbines takes full advantage of large propeller pitch angle state, wind energy capture ability reduces, and blade also partly plays the function of aerodynamic brake.Four-stage is comparatively needed to add unique control strategy in this stage.Need to consider the aerodynamic brake characteristic of blade.Formulate the fuzzy-adaptation PID control in this stage.

Because this stage needs to monitor computing with regard to wind power, wind wheel aerodynamic brake characteristic, wind speed, rotating speed simultaneously simultaneously.When wind speed fluctuates acutely in this stage, directly can shut down by feathering, enter into the feathering stoppage protection stage.

6) the feathering stoppage protection stage

Entering the feathering stoppage protection stage can meet any one in following two conditions: one, when work wind speed falls into interval [V _cut-out,+∞).Two, " cutting out in advance " stage that fluctuations in wind speed is violent.

When wind speed is greater than cut-out wind speed V _cut-outtime, blade will be adjusted to full feathering state with prestissimo by variable-pitch control system.Stoppage protection aerogenerator unit safe.Under " cutting out in advance " state that fluctuations in wind speed is violent, the limit load suffered by Wind turbines all will injure the safety of Wind turbines greatly, and therefore, Wind turbines needs with prestissimo, blade to be modulated full feathering state, to evade windburn.

When work wind speed satisfies condition for the moment, this stage does not need to carry out subsection fuzzy PID control, directly triggers feather actuator.When satisfy condition two time, subsection fuzzy PID controller is out of service, and triggers variable pitch controlling mechanism, perform feathering protection.

Fuzzy-adaptation PID control structure principle chart as shown in Figure 1.PID control flow as shown in Figure 2.

(2) segmented power tracking type Fuzzy PID Control Rules

This invention segmented power tracking type fuzzy-adaptation PID control, proposes a kind of three dimensionality fuzzy control theory.

Control theory structure, as shown in Figure 1.Respectively with wind speed V, power P, power variation rate PC for coordinate axes, the word set choosing linguistic variable is { NB, NM, NS, ZR, PS, PM, PB}, i.e. { negative large, in negative, negative little, zero, just little, center, honest }.The membership function of application wind speed, power, power variation rate determine that { V, P, PC}, each coordinate axes of this three-dimensional system of coordinate has independently unit scaling for the generation three-dimensional system of coordinate of word variable.By adjusting of the fringe to wind speed, power, power variation rate, and a unique corresponding coordinate points.And by all coordinate points (V, P, PC) of adjusting as independent variable territory, act on K _p, K _i, K _dto adjust function:

$\left[\begin{array}{c}{K}_p\\ K_i\\ K_d\end{array}\right]=\left[\begin{array}{c}{K}_p^{\′}(V,P,\mathrm{PC})\\ K_i^{\′}(V,P,\mathrm{PC})\\ K_d^{\′}(V,P,\mathrm{PC})\end{array}\right]+\left[\begin{array}{c}{\mathrm{\Δ}}_p\\ {\mathrm{\Δ}}_i\\ {\mathrm{\Δ}}_d\end{array}\right]$ (formula 7)

K ' in formula _p(V, P, PC), K ' _i(V, P, PC), K ' _d(V, P, PC) is fuzzy-adaptation PID control variable transitions function, Δ _p, Δ _i, Δ _dthat controlled quentity controlled variable error returns feedback.And the principle of PID controlled variable transfer function design is: when error is large or larger, selects controlled quentity controlled variable to eliminate error as early as possible, and when error is little or less, select controlled quentity controlled variable will note preventing overshoot, with the stability of system for main starting point.Choosing of membership function, carries out custom-made by each parameter such as capacity of concentration-type Wind turbines.

Emulate based on segmented power tracking type variable pitch control strategy, simulation process is as follows:

Choose the class wind field that turbulivity is higher.

Turbulivity I _ref=0.16;

The average reference wind speed V of 10 minutes _ref=50m/s;

The extreme wind speeds V met for 50 years one _e50(z)=1.4V _ref(z/z _hub) ^0.11;

The extreme wind speeds V met for 1 year one _e1(z)=0.8V _e50(z);

Longitudinal scale of turbulence ${\mathrm{\Λ}}_1=\left\{\begin{array}{cc}0.7z& z\≤60m\\ 42m& z>60m\end{array}\right.;$

Turbulent flow standard deviation ₁=I _ref(0.75V _hub+ b), b=5.6m/s;

Extreme fitful wind model $V_{\mathrm{gust}}=\min \{1.35(V_{e1}-V_{\mathrm{hub}}),3.3({\mathrm{\σ}}_1/1+0.1D/{\mathrm{\Λ}}_1)\};$

Wind speed $V(z,t)=\left\{\begin{array}{cc}V\left(z\right)-0.37V_{\mathrm{gust}}\sin (3\mathrm{\&pi;t}/T)(1-\cos (2\mathrm{\&pi;t}/T))& t_{\mathrm{start}}\&le;t\&le;t_{\mathrm{start}}+T\\ V\left(z\right)& t<t_{\mathrm{start}},t>t_{\mathrm{start}}+T\end{array}\right.;$

Emulation duration T=10.5s.

Computation model is the demo_a model in GH Bladed, and design parameter is:

Unit rated power P _e=2MW, rotor diameter D=80m, hub height z _hub=60m, wheel hub wind speed V _hub=12m/s, obtains σ according to above calculation of parameter ₁=2.336m/s, V _e1=56m/s, V _gust=6.47m/s.

Concentrated type unit wind speed increases to original 1.8 times and calculates the parameter made new advances and be:

σ ₁＝3.488m/s V _e1＝100.8m/s V _gust＝9.669m/s

Calculate three kinds of situations, the extreme fitful wind under rated wind speed, the extreme fitful wind under high wind speed, the extreme fitful wind under high change oar speed (12 °/s).

Through simulating, verifying, this controlling method can effectively be applied among concentarted wind energy Wind turbines, carries out power tracking and control.Simulation result is shown in Fig. 3-7.

The present invention carries out segmented fuzzy variable pitch control by power tracking to Wind turbines.For the limitation that PID controller parameter is adjusted not easily, use basic theories and the method for fuzzy mathematics, the condition of rule, operation fuzzy set represents, and using these fuzzy control rules and for information about as knowledge stored in computer literacy storehouse, then computer is according to the real response situation of control system, use fuzzy reasoning, automatic realization the best to pid parameter is adjusted, and subsection fuzzy controls to have fully taken into account concentarted wind energy Wind turbines changed power characteristic, the working state of unit is carried out Discrete control, namely the non-linearization degree of controlled device can be reduced in each interval, simultaneously also by parameter K _p, K _i, K _dadjust and simplify, given full play to that its structure is simple, good stability, reliable operation, advantage easy to adjust.

In controlling method, add " power buffering " and " cutting out in advance " stage, by stages section adopts the pid parameter be suitable for carry out variable pitch control, reduces concentarted wind energy Wind turbines 1-n ³the power oscillation that power characteristic causes.Improve the accuracy of control, real-time.

Variable pitch control strategy is by the control to propeller pitch angle, reduce the incision wind speed of traditional concentarted wind energy Wind turbines, wind-driven generator can be devoted oneself to work under lower wind speed, also improve the excision wind speed of unit simultaneously, make the absorption wind energy that unit can be stable under higher wind speed.Widened the operation interval of unit, improve unit to various wind regime adaptive capacity.

Therefore fuzzy variable pitch control strategy makes concentarted wind energy Wind turbines to maximization, industrialization, is incorporated into the power networks and develops into possibility.

The above; be only the present invention's preferably embodiment, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.

Claims (3)

1., based on a concentarted wind energy Wind turbines variable pitch control method for PD characteristic, it is characterized in that, comprising:

Step 1, according to different wind speed; concentarted wind energy Wind turbines operating mode is divided into six stages: treat the wind stage, power rises to the stage, power buffer stage, rated power stablize the output stage, cut out stage, feathering stoppage protection stage in advance; wherein front double teacher corresponding following wind speed interval respectively: [0, V _cut-in), [V _cut-in, V _95%ref), [V _95%ref, V _105%ref), [V _105%ref, V _180%ref), [V _180%ref, V _cut-out), wherein, V _cut-infor incision wind speed, V _95%refbe the rated wind speed of 95%, V _105%refbe the rated wind speed of 105%, V _180%refbe the rated wind speed of 180%, V _cut-outfor cut-out wind speed;

Step 2, when wind speed was in until the wind stage, the blade working of concentarted wind energy Wind turbines is under zero propeller pitch angle state, and variable-pitch control system is standby, and wind treated by complete machine;

Step 3, when wind speed be in power rise to the stage time, under the state that the blade working of concentarted wind energy Wind turbines is zero at propeller pitch angle, and carry out power tracking monitoring;

Step 4, when wind speed is in power buffer stage, power buffer stage is divided into buffering Interval I [V _95%, V _ref) and buffer area between II [V _ref, V _105%ref), thus between two buffer areas on carry out the linearization that is similar to, choose different domains, use different fuzzy control rules to carry out subsection fuzzy PID control; V _reffor rated wind speed;

Step 5, when wind speed be in rated power stablize the output stage time, rated power being stablized the output stage is divided into specified Interval I [V _105%ref, V _150%ref) and specified interval II [V _150%ref, V _180%ref), thus choose different domains in two specified intervals, use different fuzzy control rules, to reduce error, carry out subsection fuzzy PID control, V _150%refit is the rated wind speed of 180%;

Step 6, when wind speed be in cut out the stage in advance time, the aerodynamic brake characteristic of blade, rotating speed are joined in control strategy and carry out fuzzy-adaptation PID control; When wind speed exceeds threshold value in this stage, then directly feathering is shut down, and enters into the feathering stoppage protection stage;

Step 7, be in [V when wind speed _cut-out,+∞) interval time, blade is adjusted to full feathering state rapidly by variable-pitch control system; Stoppage protection aerogenerator unit safe.

2. method according to claim 1, it is characterized in that, described subsection fuzzy PID control method comprises independently fuzzy tuning K _p, K _i, K _dlink, PID controlling unit, Error Feedback link, concrete steps are as follows:

Step 101, respectively with wind speed V, power P, power variation rate PC for coordinate axes, the word set choosing linguistic variable is { NB, NM, NS, ZR, PS, PM, PB}, i.e. { negative large, in negative, negative little, zero, just little, center, honest };

Step 102, application wind speed, power, power variation rate membership function determine word variable generation three-dimensional system of coordinate V, P, PC}, each coordinate axes of this three-dimensional system of coordinate has independently unit scaling;

Step 103, adjusting by the fringe to wind speed, power, power variation rate, and a unique corresponding coordinate points, by all coordinate points (V, P, PC) of adjusting as independent variable territory, act on PID controlled variable K _p, K _i, K _dfunction of adjusting;

Step 104, set the error of output power as E, error be changed to EC, propeller pitch angle be changed to U, the word set choosing the linguistic variable of E, EC, U is { NB, NM, NS, ZR, PS, PM, PB}, i.e. { negative large, in negative, negative little, zero, just little, center, honest };

Step 105, be givenly input as step signal, select following domain and relevant membership function thus, the fuzzy set of getting input E and EC for NB, NM, NS, ZR, PS, PM, PB}, domain is e={-30,30}, ec={-60,60}; In like manner, output K is got _pdomain be {-0.3,0.3}; Get and export K _idomain be {-0.06,0.06}; Get and export K _ddomain be {-3,3}.

3. method according to claim 2, is characterized in that, described PID controlled variable K _p, K _i, K _dfunction expression of adjusting be:

$\left[\begin{array}{c}{K}_p\\ K_i\\ K_d\end{array}\right]=\left[\begin{array}{c}{K}_p^{\&prime;}(V,P,\mathrm{PC})\\ K_i^{\&prime;}(V,P,\mathrm{PC})\\ K_d^{\&prime;}(V,P,\mathrm{PC})\end{array}\right]+\left[\begin{array}{c}{\mathrm{\&Delta;}}_p\\ {\mathrm{\&Delta;}}_i\\ {\mathrm{\&Delta;}}_d\end{array}\right]$

K ' in formula _p(V, P, PC), K ' _i(V, P, PC), K ' _d(V, P, PC) is fuzzy-adaptation PID control variable transitions function respectively, Δ _p, Δ _i, Δ _dit is controlled quentity controlled variable error minus feedback.