CN101592126A - The wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method - Google Patents

Abstract

The present invention has announced a kind of wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method, belongs to wind power generating set operation control technique field.Controlling method of the present invention comprises the steps: at first, in unit starting is incorporated into the power networks the process that just begins to generate electricity, regulates the rotational speed omega of unit; Secondly, when wind speed changes, the direction that the relative variation of the wind speed of measuring according to air velocity transducer increases or reduces, determine that generating unit speed control needs the increase of variation or the direction of minimizing, size according to the variation of measuring wind speed value relative quantity, by tip speed ratio λ calculation expression, calculate and determine the needed control variable quantity of rotating speed; Once more, by increasing or reduce the coarse adjustment of unit output power; At last, the mechanical output P that wind turbine is absorbed _mSatisfy dP _mThe condition of/d ω=0 makes unit operation in C _PThe summit of-λ curve or with its quite approaching point.The present invention can realize the rapid track and control to direct-drive permanent magnet synchronous aerogenerator group maximal wind-energy capture, improves the power benefit of unit.

Description

The wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method

Technical field

Wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method of the present invention belongs to wind power generating set operation control technique field.

Background technique

Wind energy is the renewable energy sources of cleaning, reaching its maturity and the through engineering approaches utilization of wind generating technology, make the wind-powered electricity generation cause come into one's own and greatly develop that along with the quick growth of wind-powered electricity generation unit electric motor power, people more and more pay attention to the safe and stable operation and the power benefit of wind-powered electricity generation unit in countries in the world.The direct-drive permanent magnet synchronous aerogenerator group has not only reduced failure rate of machinery owing to saved heavy gear case transmission mechanism, has also improved unit generation efficient, thereby has become the development trend of wind-powered electricity generation unit.Because the special machine structural characteristics of wind turbine, the size of the mechanical output of its absorption not only depends on the size that acts on wind speed, also depend on generating unit speed, thereby how to regulate the rotating speed of unit, and make unit realize maximal wind-energy capture, become the key of wind-powered electricity generation unit operation control technique.

For realizing the maximal wind-energy capture of unit, the operation control technique that the wind-powered electricity generation unit adopts has multiple, be divided into the input torque of controlling unit and the output torque of controlling unit generally, typical practice has: when (1) changes when wind speed, according to the output power P of the given optimization of producer _eP with wind speed v _e-v curve, the output power of corresponding adjustment and assurance unit.The defective of this method is: the high-acruracy survey that must depend on wind speed, and in the engineering reality, the wind wheel area of MW level unit is very big, with the measuring wind speed value of which measuring point as the actual equivalent stressed wind speed of unit, also need further research, thereby with respect to the tracking of the maximal wind-energy capture operating point under each measuring point wind speed, its degree of regulation, governing speed can't guarantee.(2) the mechanical output representation that absorbs according to wind turbine $P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3,$ C in the formula _PBe the wind energy capture coefficient, ρ is air density (kg/m ³), S is wind wheel area (m ²), v is the upstream wind speed (m/s) of impeller, trying to achieve and acting on epitrochanterian machine torque is T _m=P _m/ ω does to derive accordingly, and T is arranged _m=k _Optω ², coefficient $k_{\mathrm{opt}}=\frac{1}{2}{C}_P\mathrm{\ρS}{\left(\frac{R}{\mathrm{\λ}}\right)}^3,$ λ is a tip speed ratio, $\mathrm{\λ}=\frac{\mathrm{\ωR}}{v},$ R is impeller radius (m), with this torque adjustment instruction as generator, regulates the rotating speed of unit, makes unit follow the tracks of the operation of maximal wind-energy capture operating point.The defective of this method is: in coefficient k _OptDuring calculating, also need directly to apply to wind speed v measured value, thereby degree of regulation, governing speed can't guarantee also.(3) the mechanical output P that absorbs according to wind turbine _mSatisfy $\frac{d{P}_m}{\mathrm{d\ω}}=0$ Control target, the utilization class methods of climbing the mountain increase repeatedly exploratoryly or reduce the rotary speed instruction step-length, wait unit stable once more after, calculate the size of nearest twice power and relatively judgement $\frac{d{P}_m}{\mathrm{d\ω}}=0$ Variation tendency, the trend of retaining, wait set steady operation after, continue to sound out, until $\frac{d{P}_m}{\mathrm{d\ω}}=0,$ Make unit operation in the maximal wind-energy capture operating point.In theory, this method has certain rationality, the defective of its Project Realization is: the randomness of wind speed and fast sex change (seldom have several seconds constant), determined that control technique realizes having rapidity, " wait " of the exploratory and adjustment process of the class methods of climbing the mountain can not adapt to the demand of quick control.In a word, existing operation control technique is needing to be optimized aspect the control of adjusting fast and accurately that realizes generator maximum wind energy capture.

When wind speed changes, desirable unit operation mode is: wind speed changes to some values, this constantly, preferably the rotating speed of unit just in time runs on and the corresponding optimum value of this air speed value, certain this state only under the situation that wind speed is accurately estimated, and needs by rotational speed regulation strategy fast, make rotating speed operate in the expectation optimum in advance, this does not accomplish certainly on engineering.

Summary of the invention

The synchronous wind power generator group of the direct-drive permanent-magnetism maximal wind-energy capture tracking and controlling method that provides a kind of quick validity high is provided technical problem to be solved by this invention.This method is utilized the relative change information of wind speed, accurately determines the size and Orientation of rotational speed regulation target, the mechanical output P that wind turbine is absorbed _mSatisfy $\frac{d{P}_m}{\mathrm{d\ω}}=0$ Maximal wind-energy capture operating point control requirement, reduced time of control computing again, realized control fast and accurately.

The present invention adopts following technological scheme for achieving the above object:

Wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method of the present invention is characterized in that comprising the steps:

The first step: judge increase or the direction of minimizing and the size of regulated quantity that the wind power generating set rotating speed need be regulated, the current wind speed that runs on of described wind power generating set is v ₀, output power is P _E0, rotating speed is ω ₀Operating point, as current wind speed v ₀Change into v ₁, regulate as follows:

Work as v ₁＞v ₀Then rotating speed is regulated to the direction that increases, and works as v ₁＜v ₀Then rotating speed is regulated to reducing direction, and the wind speed variable quantity is Δ v=|v ₁-v ₀|, the size of rotational speed regulation amount is Δ ω=Δ v λ _Max/ R changeed for second step; Work as v ₁=v ₀, directly changeed for the 3rd step, wherein λ _MaxBe best tip speed ratio, ${\mathrm{\λ}}_{\max }=\frac{{\mathrm{\ω}}_{\mathrm{opt}}R}{v},$ R is an impeller radius, ω _OptBe optimum speed corresponding to the upstream wind speed v of impeller, down with;

Second step: adopt the described rotational speed regulation amount of first step Δ ω to obtain rotary speed instruction ω _Ref=ω ₀+ Δ ω, the output power instruction $P_{\mathrm{ref}}=P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3=\frac{1}{2}{C}_P\mathrm{\ρS}\·{\left(\frac{R{\mathrm{\ω}}_{\mathrm{ref}}}{{\mathrm{\λ}}_{\max }}\right)}^3,$ Adopt output power instruction P _RefObtain the output current instruction with line voltage U $I_{\mathrm{ref}}=P_{\mathrm{ref}}/\left(\sqrt{3}U\right),$ With the instruction of the output current under abc coordinate I _RefCarry out the direct-axis current setting value i of transformation of coordinates under the synchronously rotating reference frame dq coordinate _{D ref}With friendship shaft current setting value i _{Q ref}, with direct-axis current setting value i _{D ref}With friendship shaft current setting value i _{Q ref}Regulate wind power generating set through frequency variator and make the output current of wind power generating set reach setting value, wherein C _PBe the wind energy capture coefficient, ρ is an air density, and S is the wind wheel area, P _mBe mechanical output;

The 3rd step: the rotational speed omega after wind-driven generator runs on adjusting ₁=ω ₀+ Δ ω adopts mechanical output $P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3=\frac{1}{2}{C}_P\mathrm{\ρS}{\left(\frac{R{\mathrm{\ω}}_1}{\mathrm{\λ}}\right)}^3$ The thread of the direction that the check rotating speed increases and reduces: when

Be tending towards 0, then keep the rotation speed change direction, directly cause $\frac{d{P}_m}{d{\mathrm{\ω}}_1}=0$ Just stop, returning the first step; When wind speed in checkout procedure has changed to next new value, then get back to the first step immediately.

The strategy that this controlling method takes rotational speed regulation to realize step by step by a coarse adjustment of rotating speed and the method that combines of thin tuning repeatedly, has improved degree of regulation, has realized that the wind energy maximum catches the accurate tracking of operating point.When a coarse adjustment of rotating speed, utilize the relative change information of wind speed, determine the rotational speed regulation aim parameter more accurately, adopt the method for regulating the unit output power, change instantaneous section effect torque of wind turbine and rotor part, make it obtain instantaneous acceleration and deceleration torque, and realize the quick adjustment of rotating speed.Repeatedly during thin tuning, progressively dwindle the change step of output power at rotating speed, just progressively dwindle the change in rotational speed step-length, guarantee the realization of maximum power point operation constraint conditio, make the maximal wind-energy capture operating point be able to accurate location.

The advantage of controlling method of the present invention is: the step of enforcement is clear, and is independent with the governing loop maintenance of other functions of unit, simple with the interface of frequency variator governing loop, is easy to realize on engineering, do not influence realization and operation that other functions of unit are regulated.Both can with unit existing controller switchover operation in parallel, can implant the corresponding link of existing controller again, can realize that maximal wind-energy capture accurate fast of permanent magnet synchronous wind generator group followed the tracks of operation, significantly improve the power benefit of unit.

Description of drawings

Fig. 1 is the control procedure block diagram.

The flow diagram that Fig. 2 realizes for control algorithm.

Embodiment

Be elaborated below in conjunction with the technological scheme of accompanying drawing to invention:

As shown in Figure 1, the concrete regulating step of direct-drive permanent magnet synchronous aerogenerator group maximal wind-energy capture rapid track and control method of the present invention is as follows:

The first step: judge increase or the direction of minimizing and the size of regulated quantity that generating unit speed need be regulated.If the current wind speed v that runs on of unit ₀, output power P _E0, rotational speed omega ₀Operating point, existing wind speed changes, and becomes v ₁, compare v ₁, v ₀Size, if v ₁＞v ₀Then rotating speed need be regulated to the direction that increases, if v ₁＜v ₀, then rotating speed need be regulated to reducing direction, calculates Δ v=|v ₁-v ₀|, the size of rotational speed regulation amount is Δ ω=Δ v λ _Max/ R, λ _MaxBe best tip speed ratio, corresponding to specific wind wheel unit, λ _MaxBe a constant of determining, ${\mathrm{\λ}}_{\max }=\frac{{\mathrm{\ω}}_{\mathrm{opt}}R}{v},$ R is impeller radius (m), ω _OptBe optimum speed, changeed for second step corresponding to wind speed v.If v ₁=v ₀, directly changeed for the 3rd step.

Second step: get ω _Ref=ω ₀+ Δ ω calculates $P_{\mathrm{ref}}=P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3=\frac{1}{2}{C}_P\mathrm{\ρS}\·{\left(\frac{R{\mathrm{\ω}}_{\mathrm{ref}}}{{\mathrm{\λ}}_{\max }}\right)}^3,$ C in the formula _PBe the wind energy capture coefficient, ρ is air density (kg/m ³), S is wind wheel area (m ²), v is the upstream wind speed (m/s) of impeller, by P _RefMeasure U with line voltage, calculate $I_{\mathrm{ref}}=P_{\mathrm{ref}}/\left(\sqrt{3}U\right),$ According to voltage oriented or electric current (magnetic field) orientation, carry out the abc coordinate to synchronously rotating reference frame dq0 conversion, obtain the direct-axis current setting value i that frequency variator is regulated (rotational speed regulation) input _{D ref}, hand over shaft current setting value i _{Q ref}, in view of the above frequency variator (rotating speed) is implemented to regulate, make the output current of unit reach setting value, thereby carried out the quick and more accurate adjusting of a step of rotating speed.

When wind speed suddenlys change, for shortening the time that rotating speed is once regulated, according to equation of rotor motion $J\frac{\mathrm{d\ω}}{\mathrm{dt}}=T_m-T_e-D(\mathrm{\ω}-1),$ T _e=P _e/ ω, J is a rotor moment of inertia in the formula, T _mFor acting on epitrochanterian machine torque, T _eFor acting on epitrochanterian electromagnetic torque, D is the damping constant of the machine driven system at rotor place, on the engineering, because the adjusting time constant of mechanical link is big, and the adjusting time constant of electromagnetism link is little, can be earlier (in 0.02～0.04 second) output power of oppositely regulating unit fast, to unit torque impact momentum, impel rotating speed to change fast, as the needs rotating speed when increasing direction and regulate, the active power Pe that earlier quick (in 0.02～0.04 second) minimizing unit sends is 0.5Pe, makes rotating speed obtain the momentum that quickens suddenly, once after the adjusting, unit is again by the active power maximum power point corresponding points operation of sending, otherwise, need rotating speed when reducing the direction adjusting, (in 0.02～0.04 second) increases the active power P that unit sends fast earlier _eBe 1.5P _e(be no more than rated power, be made as rated power when surpassing) makes rotating speed obtain the momentum that slows down suddenly, and after once regulating, unit is again by the active power maximum power point corresponding points operation of sending.Regulate like this, can shorten the time that rotating speed is once regulated greatly, improve the rapidity of regulating.

The 3rd step: the operating point ω after rotating speed runs on once adjusting ₁=ω ₀+ Δ ω, begin to carry out the thin tuning of rotating speed, for shortening the adjusting time, can use multithreading to divide the strategy of opening operation, as being example: each two thread of direction that rotating speed increases and reduces with four thread computings, the rotation speed change step-length that thread is set is bigger, and the rotation speed change step-length that thread is set is smaller, in these four threads by $P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3=\frac{1}{2}{C}_P\mathrm{\ρS}{\left(\frac{R{\mathrm{\ω}}_1}{\mathrm{\λ}}\right)}^3$ The mechanical output P that checks that thread that wind turbine is absorbed respectively _mSatisfy

Be tending towards 0 direction, keep this rotation speed change direction, four threads of repeatedly setting directly cause $\frac{d{P}_m}{\mathrm{d\ω}}=0$ Just stop, waiting for that next measuring point wind speed changes, and gets back to the first step.Certainly, if in this calculating process, wind speed has changed to next new value, then gets back to for second step immediately, the quick tracking below continuing.Algorithm flow chart such as Fig. 2.

Claims (3)

1, a kind of wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method is characterized in that comprising the steps:

The first step: judge increase or the direction of minimizing and the size of regulated quantity that the wind power generating set rotating speed need be regulated, the current wind speed that runs on of described wind power generating set is v ₀, output power is P _E0, rotating speed is ω ₀Operating point, as current wind speed v ₀Change into v ₁, regulate as follows:

Work as v ₁＞v ₀Then rotating speed is regulated to the direction that increases, and works as v ₁＜v ₀Then rotating speed is regulated to reducing direction, and the wind speed variable quantity is Δ v=|v ₁-v ₀|, the size of rotational speed regulation amount is Δ ω=Δ v λ _Max/ R changeed for second step; Work as v ₁=v ₀, directly changeed for the 3rd step, wherein λ _MaxBe best tip speed ratio, ${\mathrm{\λ}}_{\max }=\frac{{\mathrm{\ω}}_{\mathrm{opt}}R}{v},$ R is an impeller radius, ω _OptBe optimum speed corresponding to the upstream wind speed v of impeller, down with;

Second step: adopt the described rotational speed regulation amount of first step Δ ω to obtain rotary speed instruction ω _Ref=ω ₀+ Δ ω, the output power instruction $P_{\mathrm{ref}}=P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3=\frac{1}{2}{C}_P\mathrm{\ρS}\·{\left(\frac{R{\mathrm{\ω}}_{\mathrm{ref}}}{{\mathrm{\λ}}_{\max }}\right)}^3,$ Adopt output power instruction P _RefObtain the output current instruction with line voltage U $I_{\mathrm{ref}}=P_{\mathrm{ref}}/\left(\sqrt{3}U\right),$ With the instruction of the output current under abc coordinate I _RefCarry out the direct-axis current setting value i of transformation of coordinates under the synchronously rotating reference frame dq coordinate _{D ref}With friendship shaft current setting value i _{Q ref}, with direct-axis current setting value i _{D ref}With friendship shaft current setting value i _{Q ref}Regulate wind power generating set through frequency variator and make the output current of wind power generating set reach setting value, wherein C _PBe the wind energy capture coefficient, ρ is an air density, and S is the wind wheel area, P _mBe mechanical output;

The 3rd step: the rotational speed omega after wind-driven generator runs on adjusting ₁=ω ₀+ Δ ω adopts mechanical output $P_m=\frac{1}{2}{C}_P\mathrm{\ρS}{v}^3=\frac{1}{2}{C}_P\mathrm{\ρS}{\left(\frac{R{\mathrm{\ω}}_1}{\mathrm{\λ}}\right)}^3$ The thread of the direction that the check rotating speed increases and reduces: when

Be tending towards 0, then keep the rotation speed change direction, directly cause $\frac{{\mathrm{dP}}_m}{d{\mathrm{\ω}}_1}=0$ Just stop, returning the first step; When wind speed in checkout procedure has changed to next new value, then get back to the first step immediately.

2, wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method according to claim 1, it is characterized in that described second step also comprises wind speed sudden change controlling method, when wind speed suddenlys change, promptly in 0.02～0.04 second, oppositely regulate the output power of unit earlier fast, to wind power generating set torque impact momentum, concrete steps are as follows:

A) when rotating speed when increasing direction and regulate, in 0.02～0.04 second, reduce the active power P that wind power generating set is sent earlier fast _eBe 0.5P _e, after once regulating, wind power generating set is again by the active power maximum power point corresponding points operation of sending;

B) when rotating speed when reducing direction and regulate, in 0.02～0.04 second, increase the active power P that wind power generating set is sent earlier fast _eBe 1.5P _e, after once regulating, wind power generating set is moved by the active power maximum power point corresponding points of sending again, the active power 1.5P that the wind power generating set after wherein increasing is sent _eBe no more than rated power, the active power 1.5P that the wind power generating set after increasing is sent _eBe made as rated power when surpassing rated power.

3, wind energy capture of directly driven permanent magnet synchronous wind generating set tracking and controlling method according to claim 1 and 2, it is characterized in that described the 3rd step verifies as the multithreading check, Thread Count is 4n, and wherein n is a natural number, each 2n of direction thread that rotating speed increases and reduces.

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