CN105134490A - Method for improving economy of wind turbine generator set - Google Patents

Abstract

The invention discloses a method for improving economy of a wind turbine generator set. According to the method, the incoming wind speed and wind direction of high wind turbine generators are measured accurately and introduced into a yaw control system of the set as control variables to participate in optimization of yawing control and maximum Cp tracking control, so that wind wheels capture wind energy to the largest extent; the generated power is increased, and the economy of the set is improved.

Description

Improve the method for wind power generating set Economy

Technical field

The present invention relates to wind generating technology, specifically, is a kind of method improving wind power generating set Economy.

Background technique

Wind energy due to have widely distributed, can reuse and the advantage such as technology maturation, one of renewable energy sources form having become most practicability.Modal Wind Power Utilization mode is in the past few decades that the wind power generating set capturing wind energy by being equipped with wind wheel generates electricity.The wind wheel of current wind power generating set operates in bottom, near-earth boundary layer mostly, wind regime affects larger by earth's surface situation, wind speed presents the feature such as randomness, discontinuity, and wind energy is one not managed resource, and the output characteristics improving wind power generating set by changing wind regime is impossible.

The instrument for wind measurement of current wind power generating set is mainly arranged on vane and the wind vane of nacelle top, for upwind wind power generating set, its wind speed and direction recorded not is the wind regime before wind wheel, and be through the wind regime after rotating wind wheel (as shown in Figure 2 B place wind regime), be subject to the impacts such as wind wheel rotation disturbance and wake flow, not there is authenticity and real-time.In addition, vane, wind vane are Mechanical measurement instrument, have rotary inertia, and China's blower fan major part is arranged on, and dust storm is large, the field locations of very cold, easily corrodes and icing effect by dust storm, causes measuring accuracy low, fragile.Therefore, the wind speed recorded, wind direction are generally used for the start and stop protection of blower fan and simple control etc. of going off course, and for control strategy, are not reliable, effective input quantities.

At present on controlling for the research improving wind power generating set and exert oneself, substantially all from optimization driftage to wind and optimize maximum Cp tracing control two aspect and carry out, its common requirement is exactly the Measurement accuracy for incoming flow wind regime, and wind wheel is parts with very large rotating inertia, this just proposes again a control overflow to the optimization of maximum Cp tracing control, namely needs to predict in advance wind regime information with the shortcoming such as delayed compensating that huge inertia brings.

Summary of the invention

In order to improve the performance driving economy of blower fan, the invention provides a kind of technological scheme, the wind regime signal of lidar is introduced control system, solves the shortcomings such as traditional vane and wind direction mapping wind poor accuracy, reliability are low, optimize maximum Cp tracing control and driftage controls to improve generated energy wind.

Technological scheme of the present invention is:

A kind of method improving wind power generating set Economy, incoming flow wind speed, the wind direction of Measurement accuracy height wind-driven generator, and it can be used as controlled variable to introduce set yaw control system, participate in optimizing driftage to control and maximum Cp tracing control wind, make wind wheel capturing wind energy to greatest extent, increase generated output, improve unit economy.

The incoming flow wind speed of described measurement wind-driven generator, the concrete grammar of wind direction is, a set of measuring device is set, if wind power generating set front certain distance is measuring point, to measuring point Emission Lasers, after laser beam encounters the particle in measuring point air, there is scattering, the laser beam of scattering being returned contrasts with laser beam when launching, draw movement velocity and the direction of measuring point atmospheric particles, according to particle principle is followed to air motion, the movement velocity of particle equals air motion speed, the moving direction of particle and air motion direction, thus learn the wind speed and direction of measuring point.

Described measuring device comprises laser generator, transmitter, receiver, signal processor, described laser generator gives off laser beam, described transmitter by laser beam beaming to measuring point, described receiver receives the laser beam of returning from measuring point scattering, described signal processor processes the laser beam that scattering is returned, and draws the wind speed and direction measured value of measuring point.

Beneficial effect of the present invention:

Implement technique scheme, wind speed, the wind direction signals of wind power generating set front certain distance is recorded by LDV technique, be not vulnerable to the impacts such as wind wheel rotation disturbance and wake flow, relative to traditional anemoscope and wind vane, its accuracy and reliability are greatly improved, being recorded signal is incorporated in control algorithm, on original control basis, optimize driftage to control and maximum Cp tracing control wind, make wind wheel capturing wind energy to greatest extent, increase generated output, thus improve Economy.

Accompanying drawing explanation

Fig. 1 is LDV technique schematic diagram.

Fig. 2 is principle of the invention figure.

Fig. 3 is that driftage is to wind schematic diagram.

Fig. 4 is torque feedforward control block diagram.

Fig. 5 is the tip speed ratio curve of best propeller pitch angle.

Fig. 6 is torque feedforward control block diagram.

Embodiment

First, consider to introduce wind speed as control inputs, but the wind speed that traditional instrument for wind measurement records can not be used as controlled quentity controlled variable input, therefore considers to adopt new measuring wind method.New method of measurement needs to have following feature:

1. can detect the wind speed of a blower fan front segment distance far away, wind direction situation;

2. be not vulnerable to the impact of wind wheel rotation and wake flow;

3. can work under Various Complex wild environment;

4. measurement accuracy is good, and reliability is high;

5., from site operation angle, be easy to install, test and safeguard.

Anemometry laser radar is that light source is to atmospheric emission laser pulse with laser, receive the backscatter signal of atmospheric particles (mainly particulate and atmospheric molecule), calculate wind speed by the Doppler shift analyzing Emission Lasers and scattering laser, Fig. 1 is LDV technique schematic diagram.

Laser generator produces light source, launched by transmitter, transmitter can carry out fixed point and focus on, to determine the position needing the wind speed measured, after laser beam encounters the particle determined in distance air, carry out scattering, receiver receives the laser beam that scattering is returned, by contrasting with laser beam when launching, draw the movement velocity of measuring point particle.

Because the particulate in air has good followability to air motion, and as described above, and atmospheric particles is mainly caused by particulate and atmospheric molecule scattering the scattering of laser beam, therefore can draw the following conclusions:

Atmospheric particles movement velocity=wind speed

Atmospheric particles moving direction=wind direction

Thus also just recorded wind speed and direction.

Secondly, introduce air-blower control according to the wind speed recorded, assist controlling torque by fluctuations in wind speed, directly control driftage by wind vector, improve effective absorption of wind energy.

This programme mainly contains following advantage:

1, adopt lidar measurement wind wheel front certain distance wind direction, measurement result does not affect by wind wheel rotation, wake flow etc., and accuracy is good, reliability is high, thus can reduce wind deflection, improves wind energy and absorbs, improve wind energy utilization.If wind vector is excessive, exceedes design maximum yaw angle, can shut down in advance to ensure safety.

2, a feedforward control link is introduced, wind speed is regarded as a kind of disturbance, when there is fluctuation in wind speed, regulated by rotary speed-torque controller again after not needing the fluctuation of speed by the time, but directly respond fluctuations in wind speed, assist controlling torque system according to wind speed, improve speed of response, keep optimum tip-speed ratio, improve output characteristics.

3, for the seat in the plane of extreme terrain, its long-term wind regime data can be analyzed, formulate sector management scheme etc. to check its wind regime conditioned disjunction.

4, when carrying out LOAD FOR, need to carry out modeling to wind, the wake effect of upstream blower fan is particularly inevitably subject at wind field middle and lower reaches blower fan, therefore the rationality of wake model also can be verified by the wake flow wind speed of actual measurement, revised our simulated environment by measured data, improve the accuracy of LOAD FOR.

5, the stability of Feedforward Controller Design not influential system, therefore still according to original design method design speed-torque controller, can carry out the design of feedforward pilot controller, thus ensure that new controller has good compatibility on this basis again.

The present invention is by LDV technique measuring wind wind direction, realize the detection in advance to certain distance wind regime before wind wheel, thus avoid the impacts such as wind wheel rotation disturbance and wake flow, ensure that accurate letter and the reliability of signal, in order to optimize driftage, wind is controlled and maximum Cp tracing control, achieve blower fan optimal design, it realizes principle as shown in Figure 2.Fig. 2 represents a horizontal axis upwind wind power generating set, by being arranged on the LDV technique on the meteorological frame of nacelle top, the wind speed of blower fan front incoming flow, the wind direction information wind speed of A place (in the Fig. 2) can be detected.

1. optimize driftage to control wind

Wind direction has randomness and discontinuity, and uncontrollable, therefore, in order to capturing wind energy to greatest extent, needs adjustment wind wheel direction in real time, makes wind wheel all the time just to incoming flow wind direction.

Traditional mechanical type flow direction vane, major part is all arranged on nacelle rear (shown in Fig. 2), is therefore unavoidably subject to wake of rotor impact, wind direction measurement result is inaccurate, thus blower fan is not necessarily in just to incoming flow wind speed direction, and wind deflection is comparatively large, finally affects blower fan generated energy.

When there is the deviation of θ angle in incoming flow wind speed and wind wheel plane of rotation normal direction (shown in Fig. 3), the active constituent of incoming flow wind speed V is:

V ₁＝Vcosθ(1)

The most strong wind power P that blower fan can absorb _maxfor:

$P_{\max }=\frac{1}{2}{\mathrm{\ρ\πR}}^2{C}_p({\mathrm{\λ}}_{opt},{\mathrm{\β}}_{opt}){\left(V\cos \mathrm{\θ}\right)}^3---\left(2\right)$

Adopt lidar optimization driftage to wind, its maximum advantage is the input controlled as driftage by wind wheel front certain distance wind direction, thus the impact of wind wheel rotation and wake flow is not vulnerable to, improve degree of accuracy and reliability, more effective complete driftage wind is controlled, thus improve wind energy absorption, increase generated energy.

2. optimize maximum Cp tracing control

The wind speed that LDV technique is monitored, as control inputs amount, participates in controlling, and controls, on basis, to increase a wind speed feedforward control unit at original rotary speed-torque, as shown in Figure 4, is the torque controller after optimization in dotted line frame.

Generator adopts maximum C at gear shift stage _ptracking Control Strategy, as long as namely meet optimum tip-speed ratio such as formula (3), blower fan just can reach maximum C _pwind energy absorbs, and traditional controller is only input quantity with generator speed, and control strategy is such as formula shown in (4), (5).

$\mathrm{\λ}=\frac{\mathrm{\Ω}}{v}R---\left(3\right)$

$k=\frac{1}{2}{\mathrm{\ρ\πR}}^5\frac{C_p({\mathrm{\λ}}_{opt},{\mathrm{\β}}_{opt})}{G^3{\mathrm{\λ}}_{opt}^3}---\left(4\right)$

T _c＝kω ²(5)

Wherein: λ is tip speed ratio, λ _optfor optimum tip-speed ratio, Ω is wind speed round, and R is wind wheel radius, and ρ is air density, and G is gear-box speed increasing ratio, β _optfor best propeller pitch angle, v is wind speed, and ω is generator speed.

It can thus be appreciated that, remain on optimum tip-speed ratio λ to ask unit _optlower operation, then need rotating speed follow the change of incoming flow wind speed all the time and change, but due to wind wheel be parts with very large rotating inertia, when wind speed is converted into rotation speed change by wind wheel, then adopt rotary speed-torque to control, be difficult to keep optimum tip-speed ratio λ _optrun, actual is at λ _optneighbouring operation, thus cause C _pdecline, Fig. 5 represents, if the average turbulent flow of wind speed is about 15%, then unit actual motion is in the deviation area of tip speed ratio 8.1-10.9, and 15% is not large for the turbulent flow value of little wind, and additional driftage is not good to wind, then may cause C _ppoorer.

Compensate one of method of wind wheel huge inertia, utilize controls in advance link (feedforward control) exactly, carry high-revolving acceleration or retardation changes respond wind speed.Such as, in one section of fitful wind, if wind speed can be utilized to change acceleration or the speed-down action of predicting rotating speed, just can realize participating in direct torque in advance to compensate the huge inertia of wind wheel.

Utilize the resulting torque of blower fan can predict the fluctuation situation of wind speed round such as formula (6), be introduced into traditional T _ccontrol, then be multiplied by a factor of influence K _oTRto ensure unit operation safety, such as formula (7), control block diagram as shown in Figure 6.

$T_{aero}-T_{shaft}=J\stackrel{\·}{\mathrm{\ω}}---\left(6\right)$

T _dem＝kω ²-K _OTR(T _aero-kω ²)(7)

$T_{aero}=\frac{1}{2}{\mathrm{\ρ\πR}}^2{C}_p({\mathrm{\λ}}_{opt},{\mathrm{\β}}_{opt})v_{LIDAR}^2---\left(8\right)$

Wherein, T _aerofor pneumatic torque, T _shaftshaft torque, T _demfor given torque, J is the rotary inertia of wind wheel, v _lIDARfor the wind speed of lidar measurement.

Shown in Fig. 6, after utilizing the wind speed of certain distance before lidar measurement blower fan, utilize resulting torque can predict the acceleration or deceleration process of wind speed round, an additional feedforward control unit on the basis of traditional controller (in dotted line frame), carry out rotary speed-torque control in advance, ensure to run under optimum tip-speed ratio as far as possible, make to diminish between the deviation area in Fig. 5.

Adopt LDV technique to improve the invention of wind power generating set Economy, improve wind energy utilization, reduce costs significant.And it has easy realization, do not need to do too much transformation to existing operation blower fan system, there is adaptability widely simultaneously, can use under various circumstances, the present invention does not too much limit equipment, and choosing equipment is easy, realize risk less, there is good application advantage.

Claims (3)

1. improve a method for wind power generating set Economy, incoming flow wind speed, the wind direction of Measurement accuracy height wind-driven generator, and it can be used as controlled variable to introduce set yaw control system, participate in optimizing driftage and wind to be controlled and maximum cptracing control, makes wind wheel capturing wind energy to greatest extent, increases generated output, improves unit economy.

2. the method improving wind power generating set Economy as claimed in claim 1, it is characterized in that: the incoming flow wind speed of described measurement wind-driven generator, the concrete grammar of wind direction is, a set of measuring device is set, if wind power generating set front certain distance is measuring point, to measuring point Emission Lasers, after laser beam encounters the particle in measuring point air, there is scattering, the laser beam of scattering being returned contrasts with laser beam when launching, draw movement velocity and the direction of measuring point atmospheric particles, according to particle principle is followed to air motion, the movement velocity of particle equals air motion speed, the moving direction of particle and air motion direction, thus learn the wind speed and direction of measuring point.

3. the method improving wind power generating set Economy as claimed in claim 2, it is characterized in that: described measuring device comprises laser generator, transmitter, receiver, signal processor, described laser generator gives off laser beam, described transmitter by laser beam beaming to measuring point, described receiver receives the laser beam of returning from measuring point scattering, described signal processor processes the laser beam that scattering is returned, and draws the wind speed and direction measured value of measuring point.