CN103629047B - A kind of non-linear award setting method reducing load of wind turbine generator - Google Patents

Abstract

The present invention relates to a kind of non-linear award setting method reducing load of wind turbine generator, belong to technical field of wind power generation.Transmission shaft is regarded as the pseudo-linear system that take pneumatic torque as control inputs by the method, and adoption rate anomalous integral feedforward arithmetic calculates the command value of pneumatic torque, then adopts inverse approach to obtain the propeller pitch angle command value being used for rotational speed regulation; Pylon is regarded as the pseudo-linear system that take pneumatic thrust as control inputs, pneumatic thrust command value is steady state instruction value and small-signal command value sum, then adopts inverse approach to obtain the propeller pitch angle command value after considering tower oscillation damping; The propeller pitch angle command value obtained, after series connection anticipatory control link, obtains final award setting command value, for the award setting of Wind turbines.The present invention, while control Wind turbines invariablenes turning speed, effectively reduces the load of Wind turbines, contributes to the working life of reducing Wind turbines O&M cost and extending Wind turbines, and is suitable for engineer applied.

Description

A kind of non-linear award setting method reducing load of wind turbine generator

Technical field

The invention belongs to technical field of wind power generation, particularly a kind of non-linear award setting method reducing load of wind turbine generator.

Background technique

In recent years, along with the continuous increase of Wind turbines single-machine capacity, size and the weight of Wind turbines component of machine also increase thereupon.On the one hand, along with the continuous increase of Wind turbines dimension of machine parts, the load that unit bears becomes larger more complicated.On the other hand, the increase of mechanical part weight can cause the rising of complete machine cost, and Wind turbines production firm generally controls complete machine cost by the mode reducing component weight, thus causes component of machine flexibility to increase.In During Process of Long-term Operation, under the effect of larger complex load, the flexible component of Wind turbines can produce sustained oscillation, thus cause the limit load of component and fatigue load to increase, add the maintenance cost of Wind turbines, and reduce the working life of Wind turbines.Therefore, in order to reduce the cost of wind-power electricity generation, need to carry out Control of decreasing load to Wind turbines, to reduce the load that Wind turbines bears.Particularly when Wind turbines is operated in high wind speed working area, because wind speed is high, the loading problem of Wind turbines is given prominence to, so Control of decreasing load seems particularly important.

The load of Wind turbines is mainly produced by aerodynamic force, and by regulating propeller pitch angle effectively can change aerodynamic force, therefore award setting is the effective control device of one reducing load of wind turbine generator.In current commercialization Wind turbines, award setting is all adopt traditional gain scheduling proportional integral (GSPI substantially, Gain-ScheduledProportionalIntegral) method controls wind speed round, namely measure wind speed round and calculate the deviation with rated speed, adopt GSPI controlling method to calculate the control command of propeller pitch angle, the propeller pitch angle of Wind turbines is controlled.This control mode effectively can control rotating speed and the output power of Wind turbines, but does not consider the load reducing Wind turbines.For modern large-scale wind electricity unit, loading problem becomes and becomes increasingly conspicuous, and in order to reduce the cost of wind-power electricity generation, the variable pitch control method of design reduction load of wind turbine generator is the inexorable trend of Wind Power Development.

The model of Wind turbines has very strong non-linear, therefore brings difficulty to controlling method design.The controlling method of current existing reduction load of wind turbine generator mainly comprises linear processes two kinds of controlling methods.Document " A.D.Wright.Moderncontroldesignforflexiblewindturbines [R], TechnicalReportNREL/TP-500-35816, NREL, 2004. " and " W.E.LeitheadandS.Dominguez.CoordinatedControlDesignforWi ndTurbineControlSystems [C], EuropeanWindEnergyConference, 2006. " be all adopt linear control method, first the method carries out linearization for some operation points to Wind turbines, then the knowledge design linear control method of linear control theory is adopted based on the linearized model obtained.But this linear control method only has when Wind turbines is operated near the operation point chosen, its control is effective.In order to realize the control to whole high wind speed working area, need in whole working area, choose multiple different operation point and design linear control unit respectively, then suitable gain scheduling approach is adopted to dispatch these linearity control unit, to ensure the stable operation of whole system.Visible, the design comparison of linear control method is loaded down with trivial details, complicated.In contrast to this, a kind of more efficient method is that designed nonlinear control method can realize the control to whole high wind speed working area directly based on the nonlinear model design nonlinear control method of Wind turbines.The achievement in research of current nonlinear control method aspect is less.Document " D.Schlipf; D.J.SchlipfandM.K ü hn.NonlinearmodelpredictivecontrolofwindturbinesusingLID AR [J]; WindEnergy; 2012. " adopts nonlinear model predictive control method to carry out load-optimised control to Wind turbines, but the controlling method proposed is complicated, is difficult to practical application.

Summary of the invention

The object of the invention is the deficiency for overcoming prior art, a kind of non-linear award setting method reducing load of wind turbine generator is proposed, when running of wind generating set is in high wind speed working area, by the propeller pitch angle of regulating wind power unit blade, while control Wind turbines wind speed round is constant, suppress the porpoise of pylon to reduce pylon load, thus improve the economic benefit of wind-power electricity generation.

A kind of non-linear award setting method reducing load of wind turbine generator that the present invention proposes, is characterized in that, comprise following steps:

1) the pneumatic torque charcteristic function M of Wind turbines is obtained _a(Ω, β, v ₀), pneumatic thrust charcteristic function F _a(Ω, β, v ₀), the specified electromagnetic torque of the no-load voltage ratio i of gear-box, generator rated rotation speed of rotor Ω ^*with the free frequency f of pylon porpoise mode _t, wherein: Ω is wind speed round measured value, β is angle measurement value, v ₀for wind wheel effective wind speed measured value;

2) adopt encoder measure wind speed round, and through cutoff frequency be 3 Ω ^*wind speed round measured value Ω is obtained, wherein Ω after the low-pass filter of/2 π ^*for the rated rotation speed of rotor in step 1);

3) adopt velocity transducer to measure tower top speed, and pass through with frequency f _tcentered by frequency band-pass filter after obtain tower top velocity measurement v _t, wherein f _tfor the free frequency of the pylon porpoise mode in step 1);

4) wind speed measuring device is adopted to obtain wind wheel effective wind speed measured value v ₀;

5) transmission shaft is regarded as one with pneumatic torque M _afor the pseudo-linear system of control inputs, adopt linear scale anomalous integral feedforward arithmetic, according to no-load voltage ratio i, the specified electromagnetic torque of generator of the gear-box in step 1) with rated rotation speed of rotor Ω ^*, and step 2) in wind speed round measured value Ω, calculate pneumatic torque M _acontrol command

$M_a^{*}=K_{\mathrm{\Ω},p}({\mathrm{\Ω}}^{*}-\mathrm{\Ω})+K_{\mathrm{\Ω},i}\∫({\mathrm{\Ω}}^{*}-\mathrm{\Ω})\mathrm{dt}+M_g^{*}\·i---\left(1\right)$

Wherein: K _{Ω, p}represent scaling factor, K _{Ω, i}represent integral coefficient;

6) according to step 2) in wind speed round measured value Ω, the wind wheel effective wind speed measured value v in step 4) ₀, and the control command of pneumatic torque in step 5) calculate the award setting instruction being used for rotational speed regulation

${\mathrm{\β}}_{\mathrm{\Ω}}^{*}=M_a^{-1}(\mathrm{\Ω}{,M}_a^{*},v_0)---\left(2\right)$

Wherein for the pneumatic torque function M in step 1) _a(Ω, β, v ₀) inverse, select meet stable solution condition dM _athe stable solution of/d Ω < 0 is as control command

7) pylon is regarded as one with pneumatic thrust F _afor the pseudo-linear model of control inputs, according to the pneumatic thrust charcteristic function F in step 1) _a(Ω, β, v ₀), step 2) in wind speed round measured value Ω, the wind wheel effective wind speed measured value v in step 4) ₀, and the award setting instruction in step 6) calculate pneumatic thrust command value steady-state component

$F_{a,0}^{*}=F_a(\mathrm{\&Omega;},{\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*},v_0)---\left(3\right)$

8) according to tower top velocity measurement v in step 3) _t, calculate pneumatic thrust command value small-signal component

$F_{a,\mathrm{\&Delta;}}^{*}=-C_{\mathrm{\&Delta;T}}{v}_T---\left(4\right)$

Wherein C _{Δ T}represent the pylon damping increment expected;

9) according to the pneumatic thrust command value in step 7) steady-state component with the pneumatic thrust command value in step 8) small-signal component calculate pneumatic thrust command value

$F_a^{*}=F_{a,0}^{*}+F_{a,\mathrm{\&Delta;}}^{*}---\left(5\right)$

10) according to step 2) in wind speed round measured value Ω, the wind wheel effective wind speed measured value v in step 4) ₀, and the pneumatic thrust command value in step 9) calculate the propeller pitch angle command value after considering tower oscillation damping

${\mathrm{\&beta;}}_T^{*}=F_a^{-1}(\mathrm{\&Omega;}{,F}_a^{*},v_0)---\left(6\right)$

Wherein for the pneumatic thrust function F in step 1) _a(Ω, β, v ₀) inverse;

11) according to the propeller pitch angle command value after the damping of above-mentioned consideration tower oscillation through transfer function be:

$G_{\mathrm{lead}}\left(s\right)=\frac{\mathrm{\&alpha;Ts}+1}{\mathrm{Ts}+1},\mathrm{\&alpha;}>1---\left(7\right)$

Lead compensation link after, obtain final award setting command value β ^*, and be input to the feather final controlling element of Wind turbines, realize the control to Wind turbines propeller pitch angle.

Advantage of the present invention is:

1, controlling method of the present invention while control Wind turbines rotating speed, effectively can suppress the vibration of pylon, thus reduces the load of Wind turbines, contribute to the working life of reducing Wind turbines O&M cost and extending Wind turbines;

2, the realization of controlling method of the present invention does not need to make any change to the mechanical structure of Wind turbines self, only needs to change original controlling method, therefore has good Economy;

3, controlling method of the present invention only needs design gamma controller, just can realize the effective control to whole high wind speed working area, makes Controller gain variations more succinct, efficient;

4, the dynamic performance of controlling method of the present invention is good, and the control effects of rotational speed regulation and tower oscillation suppression aspect is obviously better than traditional GSPI controlling method;

5, controlling method of the present invention realizes simple, is conducive to practical application.

Accompanying drawing explanation

Fig. 1 is the control block diagram of the inventive method.

Fig. 2 is that the simulation result of controlling method of the present invention and traditional GSPI controlling method under turbulent flow wind speed contrasts.

Embodiment

The non-linear award setting method of the reduction load of wind turbine generator that the present invention proposes, as shown in Figure 1, details are as follows for embodiment for its control principle drawing:

1) the pneumatic torque charcteristic function M of Wind turbines is obtained _a(Ω, β, v ₀), pneumatic thrust charcteristic function F _a(Ω, β, v ₀), the specified electromagnetic torque of the no-load voltage ratio i of gear-box, generator rated rotation speed of rotor Ω ^*with the free frequency f of pylon porpoise mode _t, wherein: Ω is wind speed round measured value, β is angle measurement value, v ₀for wind wheel effective wind speed measured value (these data are provided by blower fan MANUFACTURER above);

2) adopt encoder measure wind speed round, and through cutoff frequency be 3 Ω ^*wind speed round measured value Ω is obtained, wherein Ω after the low-pass filter of/2 π ^*for the rated rotation speed of rotor in step 1);

3) adopt velocity transducer to measure tower top speed, and pass through with frequency f _tcentered by frequency band-pass filter after obtain tower top velocity measurement v _t, wherein f _tfor the free frequency of the pylon porpoise mode in step 1);

4) wind speed measuring device is adopted to obtain wind wheel effective wind speed measured value v ₀;

5) transmission shaft is regarded as one with pneumatic torque M _afor the pseudo-linear system of control inputs, adopt linear scale anomalous integral feedforward arithmetic, according to no-load voltage ratio i, the specified electromagnetic torque of generator of the gear-box in step 1) with rated rotation speed of rotor Ω ^*, and step 2) in wind speed round measured value Ω, calculate pneumatic torque M _acontrol command

$M_a^{*}=K_{\mathrm{\&Omega;},p}({\mathrm{\&Omega;}}^{*}-\mathrm{\&Omega;})+K_{\mathrm{\&Omega;},i}\&Integral;({\mathrm{\&Omega;}}^{*}-\mathrm{\&Omega;})\mathrm{dt}+M_g^{*}\&CenterDot;i---\left(1\right)$

Wherein: K _{Ω, p}represent scaling factor, K _{Ω, i}represent integral coefficient;

6) according to step 2) in wind speed round measured value Ω, the wind wheel effective wind speed measured value v in step 4) ₀, and the control command of pneumatic torque in step 5) calculate the award setting instruction being used for rotational speed regulation

${\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*}=M_a^{-1}(\mathrm{\&Omega;}{,M}_a^{*},v_0)---\left(2\right)$

Wherein for the pneumatic torque function M in step 1) _a(Ω, β, v ₀) inverse, the M that can provide according to producer is provided _a(Ω, β, v ₀) data obtain by tabling look-up, have 1 ~ 2 to separate, but stable solution uniquely exists), select to meet stable solution condition dM _athe stable solution of/d Ω < 0 is as control command

7) pylon is regarded as one with pneumatic thrust F _afor the pseudo-linear model of control inputs, according to the pneumatic thrust charcteristic function F in step 1) _a(Ω, β, v ₀), step 2) in wind speed round measured value Ω, the wind wheel effective wind speed measured value v in step 4) ₀, and the award setting instruction in step 6) calculate pneumatic thrust command value steady-state component

$F_{a,0}^{*}=F_a(\mathrm{\&Omega;},{\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*},v_0)---\left(3\right)$

8) according to tower top velocity measurement v in step 3) _t, calculate pneumatic thrust command value small-signal component

$F_{a,\mathrm{\&Delta;}}^{*}=-C_{\mathrm{\&Delta;T}}{v}_T---\left(4\right)$

Wherein C _{Δ T}represent the pylon damping increment expected;

9) according to the pneumatic thrust command value in step 7) steady-state component with the pneumatic thrust command value in step 8) small-signal component calculate pneumatic thrust command value

$F_a^{*}=F_{a,0}^{*}+F_{a,\mathrm{\&Delta;}}^{*}---\left(5\right)$

10) according to step 2) in wind speed round measured value Ω, the wind wheel effective wind speed measured value v in step 4) ₀, and the pneumatic thrust command value in step 9) calculate the propeller pitch angle command value after considering tower oscillation damping

${\mathrm{\&beta;}}_T^{*}=F_a^{-1}(\mathrm{\&Omega;}{,F}_a^{*},v_0)---\left(6\right)$

Wherein for the pneumatic thrust function F in step 1) _a(Ω, β, v ₀) inverse the F that can provide according to producer is provided _a(Ω, β, v ₀) data obtain by tabling look-up exist unique solution);

11) according to the propeller pitch angle command value after the damping of above-mentioned consideration tower oscillation through transfer function be:

$G_{\mathrm{lead}}\left(s\right)=\frac{\mathrm{\&alpha;Ts}+1}{\mathrm{Ts}+1},\mathrm{\&alpha;}>1---\left(7\right)$

Lead compensation link after, obtain final award setting command value β ^*, and be input to the feather final controlling element of Wind turbines, realize the control to Wind turbines propeller pitch angle.

Below an embodiment of the inventive method:

The control effects of controlling method of the present invention is described with instantiation below.This instance data comes from the WindPACT1.5MW Wind turbines of American National National Renewable Energy Laboratory exploitation.Flow process is related to according to aforementioned

1) the pneumatic torque charcteristic function M of Wind turbines is obtained _a(Ω, β, v ₀), pneumatic thrust charcteristic function F _a(Ω, β, v ₀), the specified electromagnetic torque of the no-load voltage ratio i=87.965 of gear-box, generator rated rotation speed of rotor Ω ^*the free frequency f of=(2 π/3) rad/s and pylon porpoise mode _t=0.406Hz, these data are provided by blower fan manufacturer;

2) adopt encoder to measure wind speed round, and after the low-pass filter that cutoff frequency is 1Hz, obtain wind speed round measured value Ω;

3) adopt velocity transducer to measure tower top speed, and after the band-pass filter of frequency centered by frequency 0.406Hz, obtain tower top velocity measurement v _t;

4) wind speed measuring device is adopted to obtain wind wheel effective wind speed measured value v ₀;

5) transmission shaft is regarded as one with pneumatic torque M _afor the pseudo-linear system of control inputs, adopt linear scale anomalous integral feedforward arithmetic, calculate pneumatic torque M _acontrol command

$M_a^{*}=5.74\&times;{10}^5({\mathrm{\&Omega;}}^{*}-\mathrm{\&Omega;})+4.1\&times;{10}^5\&Integral;({\mathrm{\&Omega;}}^{*}-\mathrm{\&Omega;})\mathrm{dt}+7.04\&times;{10}^5$

6) the award setting instruction being used for rotational speed regulation is calculated

${\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*}=M_a^{-1}(\mathrm{\&Omega;},M_a^{*},v_0)$

Choose corresponding to dM _athe stable solution conduct of/d Ω < 0

7) pylon is regarded as one with pneumatic thrust F _afor the pseudo-linear model of control inputs, calculate pneumatic thrust command value steady-state component

$F_{a,0}^{*}=F_a(\mathrm{\&Omega;},{\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*},v_0)$

8) pneumatic thrust command value is calculated small-signal component

$F_{a,\mathrm{\&Delta;}}^{*}=-5\&times;{10}^4{v}_T$

9) pneumatic thrust command value is calculated

$F_a^{*}=F_{a,0}^{*}+F_{a,\mathrm{\&Delta;}}^{*}$

10) the propeller pitch angle command value after considering tower oscillation damping is calculated

${\mathrm{\&beta;}}_T^{*}=F_a^{-1}(\mathrm{\&Omega;}{,F}_a^{*},v_0)$

11) according to the propeller pitch angle command value after the damping of above-mentioned consideration tower oscillation through transfer function be

$G_{\mathrm{lead}}\left(s\right)=\frac{0.2s+1}{0.1s+1}$

Lead compensation link after obtain final award setting command value β ^*, and be input to the feather final controlling element of Wind turbines, realize the control to Wind turbines propeller pitch angle.

The dynamics simulation software FAST of American National National Renewable Energy Laboratory exploitation is adopted to carry out simulating, verifying to controlling method of the present invention.The operating range in Wind turbines high wind speed district is 12m/s-24m/s, in order to consider the control performance of controlling method of the present invention in whole high wind speed working area, carries out emulation testing respectively to following three kinds of wind regime:

(1) mean wind velocity 14m/s, turbulence intensity 5%

(2) mean wind velocity 18m/s, turbulence intensity 15%

(3) mean wind velocity 22ms/, turbulence intensity 15%

In order to weigh the control performance of controlling method of the present invention, using traditional GSPI controlling method as benchmark, control performance is analyzed.The Control performance standard considered comprises the mean square deviation of wind speed round, the damage equivalent load (DEL of pylon porpoise, DamageEquivalentLoad), the DEL of blade flapping vibration and the effective value (RMS, RootMeanSquare) of propeller pitch angle variance ratio.Under three kinds of wind regime conditions, the control performance comparative result of controlling method of the present invention and traditional GSPI controlling method as shown in Figure 2.In figure, the value of y coordinate represents the control performance of controlling method of the present invention, with the control performance of traditional GSPI controlling method for base value, and the result after being normalized.Abscissa 1 represents the mean square deviation of wind speed round, the DEL of 2 expression pylon porpoises, and 3 represent the DEL that blade flappings vibrate, the RMS of 4 expression propeller pitch angle variance ratio.From simulation result, in whole high wind speed working area, controlling method of the present invention while effectively improving wind speed round control effects, reduce pylon load, and propeller pitch angle operating frequency can maintain previous level substantially.In addition, blade flapping vibration DEL remains unchanged substantially, and therefore controlling method of the present invention does not increase blade aerodynamic load.

Claims (1)

1. reduce a non-linear award setting method for load of wind turbine generator, it is characterized in that, comprise following steps:

1) the pneumatic torque charcteristic function M of Wind turbines is obtained _a(Ω, β, v ₀), pneumatic thrust charcteristic function F _a(Ω, β, v ₀), the specified electromagnetic torque of the no-load voltage ratio i of gear-box, generator rated rotation speed of rotor Ω ^*with the free frequency f of pylon porpoise mode _t, wherein: Ω is wind speed round measured value, β is angle measurement value, v ₀for wind wheel effective wind speed measured value;

2) adopt encoder measure wind speed round, and through cutoff frequency be 3 Ω ^*wind speed round measured value Ω is obtained, wherein Ω after the low-pass filter of/2 π ^*for step 1) in rated rotation speed of rotor;

3) adopt velocity transducer to measure tower top speed, and pass through with frequency f _tcentered by frequency band-pass filter after obtain tower top velocity measurement v _t, wherein f _tfor step 1) in the free frequency of pylon porpoise mode;

4) wind speed measuring device is adopted to obtain wind wheel effective wind speed measured value v ₀;

5) transmission shaft is regarded as one with pneumatic torque M _afor the pseudo-linear system of control inputs, adopt linear scale anomalous integral feedforward arithmetic, according to step 1) in no-load voltage ratio i, the specified electromagnetic torque of generator of gear-box with rated rotation speed of rotor Ω ^*, and step 2) in wind speed round measured value Ω, calculate pneumatic torque M _acontrol command

$M_a^{*}=K_{\mathrm{\&Omega;},p}({\mathrm{\&Omega;}}^{*}-\mathrm{\&Omega;})+K_{\mathrm{\&Omega;},i}\&Integral;({\mathrm{\&Omega;}}^{*}-\mathrm{\&Omega;})dt+M_g^{*}\&CenterDot;i---\left(1\right)$

Wherein: K _{Ω, p}represent scaling factor, K _{Ω, i}represent integral coefficient;

6) according to step 2) in wind speed round measured value Ω, step 4) in wind wheel effective wind speed measured value v ₀, and step 5) in the control command of pneumatic torque calculate the award setting instruction being used for rotational speed regulation

${\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*}=M_a^{-1}(\mathrm{\&Omega;},M_a^{*},v_0)---\left(2\right)$

Wherein for step 1) in pneumatic torque charcteristic function M _a(Ω, β, v ₀) inverse, select meet stable solution condition dM _athe stable solution of/d Ω < 0 is as control command

7) pylon is regarded as one with pneumatic thrust F _afor the pseudo-linear model of control inputs, according to step 1) in pneumatic thrust charcteristic function F _a(Ω, β, v ₀), step 2) in wind speed round measured value Ω, step 4) in wind wheel effective wind speed measured value v ₀, and step 6) in award setting instruction calculate pneumatic thrust command value steady-state component

$F_{a,0}^{*}=F_a(\mathrm{\&Omega;},{\mathrm{\&beta;}}_{\mathrm{\&Omega;}}^{*},v_0)---\left(3\right)$

8) according to step 3) middle tower top velocity measurement v _t, calculate pneumatic thrust command value small-signal component

$F_{a,\mathrm{\&Delta;}}^{*}=-C_{\mathrm{\&Delta;}T}{v}_T---\left(4\right)$

Wherein C _{Δ T}represent the pylon damping increment expected;

9) according to step 7) in pneumatic thrust command value steady-state component with step 8) in pneumatic thrust command value small-signal component calculate pneumatic thrust command value

$F_a^{*}=F_{a,0}^{*}+F_{a,\mathrm{\&Delta;}}^{*}---\left(5\right)$

10) according to step 2) in wind speed round measured value Ω, step 4) in wind wheel effective wind speed measured value v ₀, and step 9) in pneumatic thrust command value calculate the propeller pitch angle command value after considering tower oscillation damping

${\mathrm{\&beta;}}_T^{*}=F_a^{-1}(\mathrm{\&Omega;},F_a^{*},v_0)---\left(6\right)$

Wherein for step 1) in pneumatic thrust function F _a(Ω, β, v ₀) inverse;

11) according to the propeller pitch angle command value after the damping of above-mentioned consideration tower oscillation through transfer function be:

$G_{lead}\left(s\right)=\frac{\mathrm{\&alpha;}Ts+1}{Ts+1},\mathrm{\&alpha;}>1---\left(7\right)$

Lead compensation link after, obtain final award setting command value β ^*, and be input to the feather final controlling element of Wind turbines, realize the control to Wind turbines propeller pitch angle.