FaizalHafiz,

WindEnergyResearchGroup,SETCenter

CONTROL ASPECTS OF WIND TURBINES

Presentation Outline

PowerinWind

MaximumPowerPointTracking

ConnectionTopologies

ActivePowerControl– How?

GridIntegration:Challenges

GridIntegration:PossibleSolutions

IntelligentControl

2

Power in the wind

Thetotalpowerthatisavailabletoawindinwatts,Pw 0.5mw v2 0.5ρAv3,

where,mw ρAvρ densityoftheair(kg/m3)A theexposedarea(m2)v thevelocity(m/s)

Themechanicalpower,Pm cp Pw 0.5cp mw v2 0.5ρcp Av3

where,cp performancecoefficient

3

Power in the wind – Bet’z Limit

Assume,inletwindvelocityis‘vi’ andtheoutputvelocityis‘vo’andthemassflowrate,mw,throughthesystemisapproximately‘ρ Avave’

where, .

Wind Power,Pw

1

Solvingformaximumvalue,

P P 0.593

Power in the wind

Cp isafunctionofbothλ&θ(pitchangle),

Cp f λ,θ

where,

Tipspeedratio,λ ωt R/vwind

ωt turbinerotationalspeed

R rotorradius

vwind windspeed.0 5 10 15

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

Tip speed ratio

Cp

Power in the wind

0 0.5 1 1.5 2 2.5 3 3.5-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4x 106

rotational speed

Mec

hani

cal p

ower

4 m/s6 m/s 7 m/s

8 m/s

9 m/s

10 m/s

11 m/s

12 m/s

13 m/s

14 m/s15 m/s

6

Power Curve ‐ Hysteresis

General Structure of WECS8

Danish Concept – Fixed Speed 9

Direct in line wind turbine system10

Doubly Fed Induction Generator (DFIG)

11

Active Power ControlHowdotheydoit?

12

Model of Wound Rotor Induction Machine13

cri32πrθcosbri3

2πrθcosarirθcossrLcsibsimut,sLasileak,sLself,sLasλ

where,dtcsdλ

csisRcsvdtbsdλ

bsisRbsvdtasdλ

asisRasv

winding,statorforequationsframe,abc in model Machine

&,

Reference Frame Theory

i ds

i driqs

iqr

120θcos120θcos

cosθ

120θsin120θsin

sinθ1sT

given by,rmation isse transfoand inver

120θcos120θsin

120θcos120θsin

cosθsinθ

32

sT

,is axes abc from axes q-d intoquantity convert to matrix tionTransforma

Control Concept –Line Voltage Oriented Control

15

dsisrdsvqsλand

qsλdrissLmL

dsiqsλ

dsiqsλqsidsλeT

by,givenisframeorientedvoltagelineintorqueneticElectromag

,

MPPT‐Maximum Power Point Tracking

Turbinecharacteristicsandtrackingcharacteristic Referencecurrentcalculationsfortrackingmaximumpowerpoint.

*eT

qsλmLssL*

dri

*driqsλ

ssLmL*

eT

Rotor Side Current Controller

Kp3 +ki3 /s

S*Lrr

Kp2 +ki2 /s

S*Lrr

Kp2 +ki2 /s

S*Lm

S*Lm

QrefIqr*

Idr*

Iqr

Idr

Ids

Iqs

Vqr*

Vdr*

Vq’

Vd’

Q

x2

x3 x4

Lss / Lmλs

MPPT

Te*

dsmsdrrrs'

q*

qr

qsmsqrrrs'

d*

dr

iLsωiLsωvv

iLsωiLsωvv

17

dsisrdsvqsλ

qsλdtdsdλ

sω1

dsisrdsv

*eT

qsλmLssL*

dri

Rotor Side Converter Control

dsisrdsvqsλ

qsλdtdsdλ

sω1

dsisrdsv

*eT

qsλmLssL*

dri

18

Grid Integration

19

Grid Integration

Concerns:

LVRT,GridSupportServices,EconomicConcerns

PossibleSolutions:

Ancillarygridsupportservices

WindPowerForecasts

IntelligentControl:NatureMimickingAlgorithms

Grid Inertia

GirdInertia:Supply– Demand

mismatch

SynchronousGenerator:Inherent

Response

WindTurbines

Inertia?

PrimaryFrequency

Support?Courtesy:GEEnergy

Intelligent Inertia Emulation

Objectives, AdaptiveInertiaControllerforIndividualWT WFlevelcontrol&Co‐ordination Short‐TermWindForecasting

Inertial Response: Challenge

6 7 8 9 10 11 12 13 14 150.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

Wind Speed (m/s)

Rot

or S

peed

and

Act

ive

Pow

er (p

u)

wrPe

G. Lalor, A. Mullane, and M. O'Malley, "Frequency control andwind turbine technologies," Power Systems, IEEETransactions on, vol. 20, pp. 1905‐1913, 2005.

Inertial Response: Possible Solution

Inertial Response: Possible Solution

0 10 20 30 40 50 60 70 80

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Time (s)

WT

Act

ive

Pow

er (p

u)

No SupportSOP-2PD

Wind Speed : 7.0 m/s

0 10 20 30 40 50 60 70 80 90 1000.72

0.74

0.76

0.78

0.8

0.82

0.84

0.86

0.88

0.9

Time (s)

WT

Rot

or S

peed

(pu)

No SupportSOP2PD

Wind Speed : 7.0 m/s

0 5 10 15 20 25 30 35 40 45 5048.2

48.4

48.6

48.8

49

49.2

49.4

49.6

49.8

50

Time (s)

Freq

uenc

y (H

z)

No SupportSOP-2PD

Wind Speed : 7.0 m/s

Inertial Response: Opportunities

0.05

0.1

0.15

0.2

0.25

0.3

7 89 10 11 12 13 14 15

0

20

40

60

Additional Power,Psupport (pu) Wind Speed (m/s)

Tim

e to

hit

the

min

imum

roto

r spe

edTs

uppo

rt,m

ax (s

)

Inertia Emulation: Proposed Approach ‐ 1

0 5 10 15 20 25 30 35 40 45 5048.2

48.4

48.6

48.8

49

49.2

49.4

49.6

49.8

50

Time (s)

Freq

uenc

y (H

z)

No SupportSOP-1SOP-2PDOSOP

Wind Speed : 7.0 m/s

Inertia Emulation: Proposed Approach ‐ 2

0 50 100 150 200 250

48.5

49

49.5

50

Time (s)

Freq

uenc

y (H

z)

No SupportPDAIC

A B

MPPT, Desirable?

29

Effects of Aggregation30

1 Wind t u r b in e 30 Wind turbines 150 Wind turbines 300 Wind turbines

Reproduced from “Wind Power in Power Systems”, Wiley, Ed. Thomas Ackermann, pp. 37

Further Possibilities 

FutureResearch Effectofwakesoninertialsupport ActivePowerControlforPrimaryFrequencySupport(PFS) Co‐ordinationofWTsforPFS WindFarmlevelControl Short‐TermWindForecasting

Nature Inspired Algorithms 

Nature Inspired Algorithms 

NeuralComputation– thebrain

EvolutionaryComputation– evolution

SwarmIntelligence– groupbehavior

Swarm Intelligence

Collectivebehaviorsof(unsophisticated)agents Nocentralizedcontrol Collective(ordistributed)problemsolving Leveragethepowerofcomplexadaptivesystemstosolvedifficultnon‐linear

stochasticproblems

Swarm in Action

Research 

JournalPublications:1. F.HafizandA.Abdennour,"Ateam‐orientedapproachtoparticleswarms,"AppliedSoftComputing(IF:2.86),

Elsevier,vol.13,pp.3776‐3791,2013.

2. F.HafizandA.Abdennour,“Optimaluseofkineticenergyfortheinertialsupportfromvariablespeedwindturbines”,RenewableEnergy(IF:3.36),Volume80,Pages629‐643,August2015.

3. F.HafizandA.Abdennour,"ANeuro‐FuzzyAdaptiveInertiaControllerforVariableSpeedWindTurbines,"RenewableEnergy,Elsevier(IF:3.36),UnderReview

4. F.HafizandA.Abdennour,"ParticleSwarmAlgorithmvariantsfortheQuadraticAssignmentProblems‐ Aprobabilisticlearningapproach",ExpertSystemswithApplications,Elsevier,(IF:2.24),pp.413‐431,2016

5. F.HafizandA.Abdennour,"Discreteteamorientedparticleswarmstosolvethequadraticassignmentproblems",IEEETransactionsonSystem,ManandCybernetics:Systems(IF:2.17),UnderReview

ConferenceProceedings: F.HafizandA.Abdennour,"OptimalInertialSupportfromtheVariableSpeedWindTurbinesusingParticleSwarm

Optimization",9thIFACSymposiumonControlofPowerandEnergySystems(CPES),2015

F.M.F.Hafiz,R.Roy,R.Maurya,andS.Ghoshal;"PSOOptimizedSmallSignalStabilityAnalysisofDFIGforWECS";CurrentTrendsinTechnology,Nirma University,Ahmadabad;286‐292;ExcelIndiaPublishers;2008.

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