Supergen Wind 2011 General Assembly poster list · PDF fileSupergen Wind 2011 General Assembly poster list 1. ... Wind Turbine Wake Modelling 10. ... and temperature probes to measure

Supergen Wind 2011 General Assembly poster list

1. John Barton – Condition Monitoring for Improved Maintenance Schedules and

Increased Turbine availability

2. Antony Beddard – Connection to Shore Reliability

3. Chris Crabtree – Wind Turbine Condition Monitoring Techniques

4. Geoff Dutton – Wind Turbine Structural Blade Model

5. Thomas Farr – Wind Turbine Aerodynamics

6. Feng Gao – Numerical simulation of wave loading on offshore wind turbine mounts

7. Siyu Gao – Survey on Offshore Wind Power Technologies and Wind Turbine Modelling

8. Amir Hajdaei – Fatigue Performance of Structural Elements for Future Wind Turbine

9. David Hankin, Michael Graham – Wind Turbine Wake Modelling

10. Terry Ho – Offshore Wind Farm Electrical Systems and Grid Connection

11. James Hughes – Mesoscale Modelling Offshore Wind

12. Ting Lei – Wind Turbine Power Electronic System Reliability

13. Antonio Luque – Offshore Networks Connection

14. Jamie Luxmoore – Experimental study of wave loading on wind turbine support structures

15. Michael Robert McGlynn – GPU Accelerated Computation of Wind Turbine Radar Cross-Sections

16. Laith Rashid – Modelling the Impact of Offshore Wind Farms on Radar

17. Alan Ruddell – Integration of energy storage

18. Adam Sayer – Wind Flow Over Forested Terrain

19. Adam Stock – Wind Turbine Controllers

20. David Thompson – Design Limits For Very Large Wind Turbines

21. Damian Vilchis, Sinisa Durovic and Sandy Smith – Wind Turbine Generator Condition Monitoring

22. Mahmoud Zaggout – Condition Monitoring Using the Wind Turbine Generator Control Loop

23. Donatella Zappalá – Automation of Wind Turbine Condition Monitoring

24. Chi Zhang and Paul Hogg – Cost-effective manufacturing wind turbines with novel materials

25. Kuangyi Zhang and Paul Hogg – Fatigue issues of ± 45° glass fibre/epoxy composite for wind turbine blades

26. Shanying Zhang and Philip Hancock – Wind Tunnel Simulation of Wake Interaction

Please note that the posters are A2 size. When print, either choose suitable paper size, or shrink the document for printing.

How can the research result be used?

Who can use the research results?

What issue does this research

address?

Unplanned shutdowns reduce turbineavailability and therefore energy yield. Theyoften also result in costly deployment ofequipment, e.g. ships and jack-up barges formaintenance. Some parts of a turbine, forexample the gearbox require a lot of timeand equipment to replace. Gearbox failuresare often caused by bearing wear, in turncaused by shaft misalignment.

Impact of this research to the wind

industry?

Condition Monitoring for Improved Maintenance Schedules and

Increased Turbine AvailabilityDoctor John Barton, Centre for Renewable Energy Systems Technology, Dept. Of Electronic and

Electrical Engineering, Loughborough University

Wind Turbine Manufacturers, Installers, Operatorsand Developers.

This data is important to operators and developersin the optimisation of their maintenanceschedules. If vibration and wear problems can bedetected early, then some mechanical failures canbe prevented. Moreover, maintenance can bescheduled to minimize the number of site visits.

Doctor John Barton+44 (0)1509 [email protected]

A Physics-Of-Failure approach will be developed.A model of the turbine system will enable anunderstanding of vibrations and failure processes.The method will be read across to commercialsized turbines and to other turbine components.

What method does this

research use?

What results were found?

A 25kW turbine at West Beacon Farm has been instrumented with vibration sensors and temperature probes to measure gearbox and bearing vibration and any resulting rises in temperature. In addition, the 3 phase voltages and currents of the generator have been recorded at a frequency of 4kHz to detect any cyclic changes in power output due to vibration problems. Finally, a light-dependent resistor detects when the sun is shining, to prevent false alarms caused by solar heat gain. The turbine works at variable speed, so vibration linked to gearbox and bearing problems will change with the rotation speed, and may be intermittent in nature.• Data has been recorded between March and October 2010• Labview data acquisition system written• Wavelet frequency analysis provides optimum balance between frequency resolution and time-dependent amplitude changes.

0

0.2

0.4

0.6

0.8

1

1.2

1.4

3 3.5 4 4.5 5 5.5 6 6.5 7

Am

plit

ud

e

Log 10 of cycles Per Hour

Voltage 0

Voltage 1

Voltage 2

Voltage 3

Voltage 4

Voltage 5

Some vibration frequencies have already beendetected and identified.

Possible blade passing frequency

GeneratorAC frequencyand its 2nd

harmonic

Alias of electronic power converterPWMfrequency

Research Applications

Research Method

Reliability of the HVDC

Connection

Many Round 3 offshore wind farms are locateda distance from the shore where high voltagedirect current (HVDC) transmission ispreferable to high voltage alternating current(HVAC) transmission. The reliability of theHVDC transmission system, as well as its effecton both the connected windfarms and the ACgrid, is the focus of my research.

Connection to Shore Reliability

Antony Beddard, Power Conversion Group,The University of Manchester

The review of HVDC CB topologies wasproduced with information from academicpapers, published patents and commerciallyavailable documentation. Software packagessuch as PSCAD and SimPower systems werealso used to simulate selected topologies.

For details contact: Antony [email protected]

A HVDC circuit breaker technology report hasbeen produced and may be useful fortransmission and distribution (T&D)manufacturers as well as grid operators. Thisresearch is also likely to be used for thepublication of academic papers.

Multi-terminal HVDC

Protection

HVDC Breaker Topologies

The ability to interconnect HVDC transmissionsystems has many benefits including improvednetwork security and reduction in offshore assetrequirements. However, the lack of HVDC circuitbreakers is a major stumbling block withoutwhich a single dc cable fault could paralyse thepower flow for all of the interconnected systems.The first objective of my research has been toassess candidate HVDC circuit breaker topologies.

A number of topologies have been assessedand the two most promising types of circuitbreaker (CB) are shown below:-

(i)Solid-State CB (ii)Hybrid CB

The solid-state circuit breaker (SSCB) offersvery fast interruption speed, but has high on-state losses, whereas the Hybrid circuitbreaker has low on-state losses, but arelatively slow interruption speed. Currentlythe SSCB is the preferred candidate sincefaster interruption is of greater importancethan on-state losses.

Another topology, which has been designedas part of this project has been shown tohave low on-state losses in comparison to theSSCB, combined with a fast interruptionspeed in comparison to the Hybrid CB.

http://www.supergen-wind.org.uk/people/AntonyBeddard.html

0 50 100 150 200 250 300 350 400 450153

154

155

156

Fre

qu

en

cy [H

z]

Result from Iterative DFTlocal

(Calculation Time = 1.046s (0.23559%))

Fault Frequency, ff

0 50 100 150 200 250 300 350 400 4500

50

100

150

200

Am

plit

ud

e

Amplitude of Fault Frequency

0 50 100 150 200 250 300 350 400 4500

50

100

150

200

Time [s]

Am

plit

ud

e

Filtered Result

Balanced Rotor 23% Asymmetry 46% Asymmetry

(a)

(b)

0 50 100 150 200 250 300 350 400 450102

103

104

105

106

Fre

qu

en

cy [H

z]



Fault Frequency, ff

0 50 100 150 200 250 300 350 400 4500

5

10x 10

4

Am

plit

ud

e


0 50 100 150 200 250 300 350 400 4500

5

10x 10

4

Time [s]

Am

plit

ud

e

Filtered Result

Balanced Rotor 23% Asymmetry 46% Asymmetry

(c)

(d)

How can the research be used?

What issue does this research address?

With the wind industry focusing on wind turbine (WT) reliability and productivity, a condition-based, lessreactive maintenance strategy is required. Condition monitoring systems (CMS) allow operators to assessthe health of individual WTs and make diagnoses and prognoses. Drive train faults have been shown tocontribute significantly to WT downtime.

Wind Turbine Condition Monitoring Techniques

Christopher J. Crabtree, New & Renewable Energy Group,Durham University

Dr Christopher J. Crabtree+44 (0)191 334 [email protected]

The algorithm could be integrated into existingCMSs rather than creating a complete new systemas structures are already available. The algorithmsignificantly reduces processing times againststandard Fourier analysis and reduces the need forspecialist analysis of complex, noisy spectraproduced from WT CM signals, giving clear resultsfor maintenance and management staff.

What method is used?


The Durham test rig is driven using speed profilesderived from a detailed WT model to emulatevariable WT conditions. Fault-like conditions can beapplied on demand. Since WT speed variesconstantly, the frequencies of fault-related spectralcomponents indicative of drive train faults also varywith time. The magnitude of a fault-relatedcomponent changes in the presence of a fault.Therefore, faults could be detected by examiningspectral component magnitude with time.The algorithm developed reduces processingrequirements as only fault-related information iscalculated rather than complete, wind-bandspectra. The stages of analysis are:• Calculate the required sample length of both the

analysis signals and machine speed signal;• Calculate the fault-related frequency of interest

from mean speed signal within time window;• Apply Fourier analysis across the narrow

frequency band around the frequency of interest;• Extract the peak amplitude (peak finding) within

the frequency window;• Repeat along entire signal and plot the peak

amplitude of each iteration against time.

Wound Rotor

Induction Generator

~

Resistive Load

Banks (Rotor)

Grid

Connection

Data Acquisition

Hardware

Current &

Voltage

Transducers

Variable

Speed Drive

Data Acquisition & Control

Environment

X & Y

Proximeters

Accelerometer

Torque

Transducer &

Shaft

TachometerGearbox DC Motor

DC

Ta

ch

om

ete

r

Experimental

Balance Plane

3 Phase

Supply

Experimental

Balance Plane

Rotor Electrical Asymmetry

0 50 100 150 200 250 300 350 400 45025.5

26

26.5

27

Fre

qu

en

cy [H

z]



Fault Frequency, f

f

0 50 100 150 200 250 300 350 400 4500

50

100

Am

plit

ud

e


0 50 100 150 200 250 300 350 400 4500

50

100

Time [s]

Am

plit

ud

e

Filtered Result

0 50 100 150 200 250 300 350 400 45025.5

26

26.5

27

Fre

qu

en

cy [H

z]



Fault Frequency, f

f

0 50 100 150 200 250 300 350 400 45040

60

80

100

Am

plit

ud

e


0 50 100 150 200 250 300 350 400 45040

60

80

100

Time [s]

Am

plit

ud

e

Filtered Result

(a)

(b)

(c)

(d)

Balanced Shaft92g, 80mm

(G 13.4)

92g, 230mm

(G 38.5)Balanced Shaft

92g, 80mm

(G 13.4)

92g, 230mm

(G 38.5)

High Speed Shaft Mass Unbalance

Who can use this model?

What issue is this research is addressing?

• A fully parametric structural wind turbine blade model has been developed and applied to a generic 5MW blade design

• The current quasi-static version of the model incorporates realistic gravity and aerodynamic loading and a full dynamic implementation is under development

• The model is available as a test-bed for materials and blade control device innovation

Wind TurbineStructural Blade Model

Dr Geoff Dutton, George EllwoodEnergy Research Unit

STFC Rutherford Appleton Laboratory

The parametric blade model is a research tool. It requires a complex set of input parameters including materials specification, layup and failure analysis. It is best used by the researchers who developed the code in collaboration with one or more of:• materials suppliers,• blade manufacturers,• full scale test laboratories,• blade condition monitoring companies

Dr Geoff Dutton+44 (0)1235 [email protected]

How can the model be used?

Distributed aerodynamic loading (via XFOIL)

• to assess the performance of innovative materials in appropriate blade locations with realistic loading conditions

• to assess the structural implications of active and passive blade control devices

• to determine the appropriate location of condition monitoring devices

• to analyse and interpret the outputs from full scale laboratory blade tests

Thermoelastic stress distribution (model)Thermoelastic stress distribution (test)

Impact of this work to the wind industry?

This work contributes to the understanding of structural load paths and static and fatigue damage processes in wind turbine blades. The model has been applied in the interpretation of condition monitoring (i.e. thermoelasticstress analysis) results from full scale blade tests. Future developments will address the impact of upstream blade wakes and/or dynamic control action on blade loads.

Wind Turbine AerodynamicsThomas Farr, Fluids Research Group

University of Surrey


address?

University of Surrey

address?The research focuses on the effect the turbine has on the

upstream turbulence and how this effect changes as it

passes through the turbine. The blockage caused by the

turbine has two effects on this turbulence; deceleration

and divergence of streamline causes the intensities of the

fluctuating components of velocity to increase, but the

blocking effectof theturbine impedesthis increase.

A

U0,p0

A0U1

p1 P1’

U2

A2,p2

Impact Hot-wire anemometry is used to measure the

What method does this research use?

Diagram of streamline divergence

Impact

industry

Hot-wire anemometry is used to measure the

background turbulence produced by two grids with

different dimensions. The grids produce turbulence that

at various longitudinal positions have different

characteristics. This will be used as the background

turbulence to test the turbines. Later the same

experiments will be made in the atmospheric boundary

What

experiments will be made in the atmospheric boundary

layer.

The results shown have highlighted four locations where;

the turbulence levels are the same, but lengthscales are

different, and the lengthscales are the same and


turbulent different, replicating the varying conditions we

seeinthereal world.

10

20

30

40

50

Inte

gra

l Le

ng

th S

cale

(m

m)

0.05

0.1

0.15

0.2

0.25

Tu

rbu

len

ce I

nte

nsi

ty,I

u (

%)

Mesh size

100mmMesh size

50mm

0

10

20 40 60

Inte

gra

l Le

ng

th S

cale

(m

m)

Streamwise Location (x/Mesh size)

0

0 20 40 60

Tu

rbu

len

ce I

nte

nsi

ty,I

u (

%)

Streamwise Position (x/Mesh size)

Results from preliminary experiments

Wind Turbine AerodynamicsThomas Farr, Fluids Research Group

University of SurreyUniversity of Surrey

1.4

1.5

1.6

1.7

u'/U ratio; w'/U

(u'/U)/(u'/U)o(w'/U)/(w'/U)o

Who can use the research results?Turbulence information is used to calculate the dynamic

Turbulence intensity amplification with increasing

thrust coefficient

1.0

1.1

1.2

1.3

1.4

0 0.2 0.4 0.6 0.8 1

u'/U ratio; w'/U

ratio

CT

Who ?Turbulence information is used to calculate the dynamic

blade loading that large rotors experience. This turbulence is

produced by atmospheric conditions as well as turbine

wakes. It is important for wind turbine manufacturers to

design the blades with enough strength for these extreme

loading conditions.


How can the research result be used?The data can be used to predict wake development and

calculate blade loading characteristics, including maximum

loading andwind farm planning.


industry?The research will provide information and have implications

for blade loading and windfarm layout.

What is the next step?The turbine will be subjected to various conditions and

Setup for further analysis

Thomas Farr

[email protected]

The turbine will be subjected to various conditions and

measurements will include three-component and phase-

locked measurements to give flow details, up and

downstream of theturbine

[email protected]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-3.14 -1.57 0 1.57 3.14

F/F

0

Phase

Numerical

Linear theory

Second orderExperimental




address?


industry?

Numerical simulation of wave loading on offshore wind turbine

mountsF Gao, C G Mingham and D M Causon

School of Computing, Mathematics & Digital TechnologyManchester Metropolitan University

Dr. Feng Gao+44 (0)161 247 [email protected]

The code allows the simulating of a wide range ofscenarios of wave impact on wind turbine mountsby simply changing parameters in the model.


research use?


Wave loading on an offshore wind turbinemount is an important factor for its structuralstability. In this work package a 3D numericalmodel is developed to simulate irregular andbreaking waves on a range of mountconfigurations, and to calculate the resultingflow properties and wave loadings (Fig 1).

This work will contribute to the understanding ofwave run-up on offshore wind turbine mounts. Itwill also provide information about the impactforces of waves breaking on the mounts.

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-3.14 -1.57 0 1.57 3.14

F/F

0

Phase

Numerical Linear theorySecond orderExperimental

-100-80-60-40-20

020406080

0 2 4 6 8 10

Ho

rizo

nta

l F

orc

e (N

)

t (s)

Fig 1: Simulation of horizontal force on a cylinder.

An two-phase flow solver, AMAZON-3D, hasbeen developed to simulate wave loading on avertical cylinder. The solver uses the artificialcompressibility method to solve theincompressible Navier-Stokes Equations. Asurface-capturing method is used to treat thefree surface as a contact discontinuity in thedensity field. The Cartesian cut cell technique isused to generate the mesh which has flexibilityto deal with complex geometries.

The numerical code was validated bycomparing some experimental and theoreticalresults with numerical results. In regular linearwaves wave run-up and wave loading on avertical cylinder good agreement was obtained(Fig 2).

(a) ka = 0.271, kH = 0.178 (b) ka = 0.481, kH = 0.438

Fig 2: Comparison of dimensionless horizontal force withexperimental and up to 2nd order potential diffraction theory.

The code will be extended to simulate irregularand breaking wave run-up and impacts onmonopile and jacket type mounts.

Wind turbine manufacturers and any interestedparties.

http://www.mmu.ac.uk/

The survey has summarized the

offshore wind power technologies to

date and has made projections on

the trend.

Types of different wind turbines hasbeen summarized and compared.

Developments of power electronicsand grid linkages have beeninvestigated and summarized.

Installation of different offshore windturbine foundations and substationshave been studied. Requiredequipment and specialist vessels havebeen identified.

Different generations of offshoresubstations have been summarized.Their main electrical components havebeen identified.

Projections on offshore energy havebeen made.

Survey on Offshore Wind Power Technologies and Wind Turbine

ModellingSiyu Gao, Power Conversion Group

University of Manchester

The wind turbine model aims to

combine the mechanical and

electrical properties of the turbine to

give comprehensive results.

The model is currently being built and isbased on permanent magnetsynchronous type wind turbine.

The wind turbine model is being built

in PSCAD.

Testing the SVPWM Modulator

The results of the survey have

suggested the possibility of a hybrid

form of offshore power generation.

It is possible to combine offshore windgeneration with tidal/wave generation.

Multiple research studies based ondifferent concepts are being carried out.

The survey provides adequate

insights and information of modern

offshore wind power.

The survey is part of a research projectwith Siemens.

The wind turbine model should be

able to predict the behaviours of the

actual turbine once finished.

The model will include a two-massmodel of the drive train.

The model will try to integrate a variablewind speed model.

Siyu [email protected]


address?The structural failure of wind turbine blades underthe influence of fatigue is a well known issue inwind turbines. To be precise, this problem risesfrom detachment or failure of spar/ spar-skin . Theblade alone cost about 25% of total cost of windturbine, any structural damage would be verycostly to deal with.

Fatigue Performance of Structural Elements for Future

Wind TurbineAmir H. Hajdaei, Prof. Paul J. Hogg

Northwest Composite Centre, University of Manchester

What method does this research

use?T-sections as a representative element of bladespar have been modified in different ways andtested under static and dynamic load (Fig. 1) .Addition of veil layer materials (i.e polyamide andpolyester veil), using 3D woven structures,


polyester veil), using 3D woven structures,stitching and changing composite fabric from glassto carbon or a combination of them, are some ofthe modifications would be done on samples.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Defl

ec

tio

n (m

m)

Lo

ad

(k

N)

Load(kN) Deflection(mm)

I-0: No Veil, C-1: 1 Layer Carbon veil, C-2: 2 Layers Carbon veil, PE-1: 1 Layer Polyesterveil, PE-2: 2 Layers Polyester veil, PA-1: 1 Layer Polyamide veil, PA-2: 2 Layers Polyamideveil, F091: Resin with Nano particles, 3001: Resin with Nano and Rubber particles

Fig. 1: T-section sample and the test rig

Fig.2: Tensile strength and deflection for different samples

Fatigue Performance of Structural Elements for Future

Wind TurbineAmir H. Hajdaei, Prof. Paul J. Hogg

Northwest Composite Centre, University of Manchester

0 5000 10000 15000 20000 25000 30000 35000 40000

Cycle Number

Fatigue data

3001

I-PA-2

I-PA-1

I-N91

Fatigue tests have been carried out at the 6 MPastress level for all samples, as shown in Fig. 3 graph, the sample made from resin containing nano and rubber particles experienced the highest number of fatigue cycle before breaking.

Fig.3: Number of fatigue cycles before breaking

It could be concluded from the graph in Fig.2 thatsample with rubber particles (3001) has themaximum tensile strength among these samples.



Impact of this research on the wind

industry?

Wind Turbine Manufacturers and Designers.

There would be two major benefits:• First by developing a structure with longerworking life, installation of the wind turbineswould be more economical and they will be morereliable• Second, use of 3D woven structure formanufacturing the blade would be much fasterthan the traditional layer by layer composite layup.

The result would help to manufacture the windturbine blade easier and with longer working lifetime. This will make the wind turbines morereliable and economical .

number of fatigue cycle before breaking.

Amirhossein [email protected]

+44 (0)161 30 65704

Wind Turbine Wake Modelling

David Hankin & Professor J. Michael R. GrahamUnsteady Aerodynamics, Imperial College London

Professor J. Michael R. Graham+44 (0)20 7594 [email protected]

David Hankin+44 (0)207 594 5042

[email protected]

How can the research result be

used?



address?

The calculation of aerodynamic loading on therotor disc in unsteady flow conditions such asthose of turbulent inflow and wind shear.

The developed code will be interfaced with theRutherford Appleton Lab structural dynamicscode to form an aeroelastic model of the rotor.

Impact of this research to the

wind industry?

Anyone interested in the aerodynamics of largearrays of wind turbines. In particular, wind turbineoperators and designers.

The developed code can be used to simulate theflow conditions surrounding a turbine in an arrayand determine the loading and efficiency of therotor.

What does this research use?

method


A free wake Vortex Lattice Method panel codehas been developed that is:

• Applied to mean camber surface.

• Capable of modelling:

Twist

Camber

Pitch

• Unsteady load calculations.

For computational efficiency the velocity isrepresented on a grid.

The unsteady response to various inlet conditionsto the rotor can be investigated, including theeffects of an upstream rotor wake.

Step response of the Power Coefficient.

The results will be used to develop further semi-empirical models to predict unsteady effects onrotor induction factors and loading for use inindustry standard BEM codes.

How can the research results be used?



The power electronics have some of the highest failurerates in a wind turbine system (Figure 1). Issues withefficiency, performance and the dynamics of the systemsare also considered in the research, as well as reliability.

Impact of this research to the

wind industry?

Offshore Wind Farm Electrical Systems and Grid ConnectionTerry Chi Young Ho, PhD, New & Renewable Energy Group

Durham University

Offshore wind farm developers, operatorsand manufacturers who wish to extend thereliability and life of the electrical systemand reduce the cost of its maintenance.

Terry Chi Young Ho+44 (0)191 33 [email protected]

The research can be use to simplify electrical systems andenhance their reliability, and reduce cost where possible.


One concept topology of interest is a radial connection fromwind turbine generator directly to the offshore substationplatform (Figure 2). All primary power electronics are centredin one location and can potentially be transformerless.Considering 5MW turbines and a distances up to 5km to theplatform: a standard 2 level converter modules at 690V is notpossible without transformers as currents reach 4185A, butcan be possible with medium voltage levels from 3.3kV with 3to 5 level converters with manageable currents of 875A,3phase. This is <5% loss over 5km copper cable with cross-sectional area of 1000mm2 (3.6cm diameter) for each core.PSCAD results are yet to be carried out to compare systemstability and dynamic response.


The research is mainly focused on the connectionbetween the wind turbine generators and the offshoresubstation where the power is collected before beingtransmitted onshore to the grid by HVDC .

A range of connection topologies were looked into andcompared. Simulation tools such as MATLAB and PSCADare used to model them.

Shifting the power converter componentsand transformers from the wind turbinehelps to keep it light weight, compact,simpler and less costly to install andassemble.If all power electronics are located at thestation along with the HVDC converters, theliquid cooling system can also be centralisedand shared, redundancies can be addedeasily in this system, and all the componentswould be more accessible, thereforemaintenance is quicker and less costly, thuseliminating the downtime and ultimatelymaximising wind energy production.

Offshore platformWind Turbine Generators

Pow

er collectio

n system

to HVDC

Figure 2: Direct connection concept, centralised power electronics

Figure 1: Contribution to overall failure rate (source: Reliawind)

Converter

The issue

Accurate resource estimation is of great

importance to the wind energy industry.

More accurate estimations optimise the

running of farms extensively, increasing

output and boosting the value of the

industry. Currently wind resource along with

a few other variables are measured directly

by meteorological masts the cost of which

typically runs to six figures, Mesoscale

models offer a viable alternative and offer a

more extensive suite of variables critical to

the accurate assessment of wind resource,

for example stability and turbulence.

Impact

Mesoscale Modelling Offshore Wind

James Hughes CREST

Loughborough University

Development of this

technology will be of

particular interest to

turbine manufacturers,

farm operators and

utility companies for

whom progress would

result in greater

knowledge of

operating parameters,

improved wind farm

efficiency and an

increased value of the

power on the trading

floors.

The benefit of Mesoscale models is the variety of

outputs which can be produced varying spatially

and temporally. Shorter term forecasts can predict

windspeed by the hour for example at particular

locations (fig 2). In the long term resource maps

are a very beneficial output (fig 3) which can

show average trends or seasonal forecasts for

example. The problem with mesoscale modelling

is the accuracy of the forecasts at specific

locations. Wind power cubes with speed and this

is a potentially significant problem. Results from a

preliminary study at Scroby Sands (Cunney,

2009) suggests wind speed error of 4-16% which

is greater than point observations from masts.


research use?


Figure 3. Annual mean wind speed at 100m.

http://www.renewables-

atlas.info/downloads/documents/Renewable_Atlas_Pages_A4_A

pril08.pdf

Mesoscale models solve the full suite of

dynamical equations as with GCM’s but for a

reduced spatial area from 1-1000’s Km. The

models are initialised with comprehensive

atmospheric conditions, usually from

reanalysis products and can be successively

nested to increase the resolution for

particular locations (fig 1.) while maintaining

large scale circulation features. During the

run real-time data can be assimilated to

‘nudge’ the model to the observed values.

Figure 1. Nesting a mesoscale model to produce high resolution outputs of surface variables.

http://fvcom.smast.umassd.edu/research_projects/LSuperior/images/mm5_model.jpg

Figure 2 Observed (Uo) and modelled (Uwrf) wind speed at 33 and 51m, Scroby sands day 209, 1996.

(Cunney, M. 2009. ‘Mesoscale modelling of coastal winds.’ Loughborough University, Unpublished).

James Hughes

01509 635312

[email protected]

Rotor Side Converter

0.00 0.50 1.00 1.50 2.00 ...

...

...

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

y (

kA

)

ir_d (kA) ir_q (kA)

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

y (

kA

)

Ir_a (kA) Ir_b (kA) Ir_c (kA)

Work package outcomes

Evaluating converter reliabilities

Electronic subassemblies in wind turbines havehigh failure rates but relatively short down time.This research is intended to investigate theconverter failure mechanism by investigating asingle wind turbine model in PSCAD. Bothmechanical and electrical stresses on theconverter should be examined. The purpose isto identify what dynamic behaviours can affectpower electronics operation and then find waysto limit or avoid the risks within a design.

Impact

Wind Turbine Power Electronic System Reliability

Ting Lei, Power Conversion GroupManchester University

Power electronic subassembly faults are asignificant factor contributing to WT downtime.This is not easy to identify and isolate due to itscomplexity and difficult to diagnose. Thedevelopment of a realistic model will facilitatethe solution of challenges faced by enhancingoverall reliability of large offshore wind turbines.

Ting Lei Tel: +44 (0)161 306 [email protected]

The developed DFIG PSCAD model, oncevalidated, can be used for the comparison withother WT models (e.g. synchronous WT), thusallowing the evaluation of converter performancein different WT concepts. The analytic resultsabout failure root cause will contribute to earlydetection of deterioration, improved designmeasures and better quality control inmanufacture.

DFIG/FMEA modelling

Results to date

A DFIG control model of the wind turbine hasalready been established by another PhD student,but has been modified in this project. Thesimulation is based on stator-flux orientedcontrol and is shown below. A preliminary FMEAhas been carried out on the electronics of severaltypes of wind turbine, considering majorcomponents. Risk priority numbers are assignedbased on industry surveys and analysis. Thequantitative results have been compared withfield data.

PSCAD DFIG model

Identify Failure Mechanism

Simulation & Experiment

Find Failure Modes

FMEA Results or Field data

Simulation

Modify

Hardware & Software

Validate tocheck it’srealizable

Grid Side Converter

0.00 0.50 1.00 1.50 2.00 ...

...

...

-0.050

0.400

y (

kV

)

vg_d (kV) vg_q (kV)

-1.00

1.00

y (

kA

)

ig_d ig_q

A dynamic model for converter reliability studiesshall be developed in PSCAD, considering all thefailure modes obtained in FMEA or field data.This involves some software simulation (PSCAD)and experimental validation.

Fig 1 Methodology Flow Chart

Fig 2 PSCAD DFIG Control Simulation

mailto:[email protected]



Offshore Networks ConnectionAntonio Luque, Institute for Energy and Environment

Strathclyde University


The research focuses on offshore wind farms powerconverter control. Development of back to back controlsystems for HVDC links.

The objective considers implementation of a multi-pointconnection schemes in Matlab&Simulink and the creationof the offshore platform to control the power output.The design strategies:• Electrical arrays for offshore wind farms• Development of models for transient studies• Control strategies design and verification• Dynamic performance assessment


The research strategy is based on the implementation of the DC networks VSC-HVDC, back to back converter. The converter control method is analysed by the implementation of the inner and outer controller scheme:1. Power controller2. VAC Controller 3. VDC Controller

it had been found that use of multi-terminal system couldimprove the transient instability against disturbances.The improvement in the control system would let windfarms be connected during these disturbances and helpnetwork introducing reactive power and active power.

Impact of this research to the wind industry?

Antonio LuquePhD [email protected]

The increment of the offshore wind energy and the lack ofinfinity DC busbar will raise control problems. Futurebusbar schemes will be DC, where multiple wind farmswould be connected and controlled independently.The development of the DC offshore busbar “platform”will contribute to control the voltage during transientinstabilities. The platform will contain the VSC converterwhich will help to recovery voltage by the injection ofactive and reactive power in the network.The dynamic models of the different control system willderive in realistic future control strategies.

Outer and Inner Current Controller

Both controllers are the Key to obtain the desired powers.The development of these controllers would let the windindustry to improve the control stability and the quality ofthe power output.

In previous research

Manufacturers and operators

could benefit from the research.

Deep water wind farms require

new support structure solutions.

Current plans to site newoffshore wind farms indeeper water presentmany engineeringchallenges. Jacket typesupport structures arelikely to be used in 30 - 60m deep water. Jacketshave been widely used bythe oil and gas industry,but are relatively new andpoorly understood in windturbine applications.

Jacket type support structures can be

optimised for site conditions

Experimental study of wave loading on wind turbine

support structuresJamie Luxmoore

Lancaster Environment Centre, Lancaster University

Jamie Luxmoore+44 (0)7963 [email protected]

Experimental study is essential

to understanding wave loads

Wave loading on wind turbines is

complex and poorly understood.

Wind turbines are tall, light structures, withwind loads applied at the top, resulting in largeoverturning moments. Wave loading is appliedlower on the structure, but in extremeconditions the loads can be large. As thestructures get taller, the wave period mayapproach the natural frequency of the structure.Wave slam and run-up may affect accessfacilities and cause high peak loads.

Scale model testing will allow

comparison of different support structures.

The Total Environment Simulator wave tank at TheDeep in Hull can produce a realistic spectrum ofirregular waves. Instrumented 1/100th scale modelsof a jacket and a monopile support structure will beconstructed and tested in a range of wave conditions.

A thorough understanding of wave loading on windturbine support structures will allow optimiseddesign for the site conditions. The use of jacketsupport structures will reduce mount weight andincrease stiffness. This will reduce the cost of thestructure and increase confidence in mountreliability.

Wind turbine maintenance access could be improvedby design for site wave conditions and structureweight and cost could be reduced.

Irregular waves, complex structures and highlydynamic turbulent flows mean the problem isnot suitable for theoretical analysis. Anexperimental measurement programme isneeded to support numerical modelling effortsand to help to understand the mechanism ofwave loading on jacket support structures.

Source: Talisman EnergySource: Hull University TES website


address?

The impact of an offshore wind turbine onradar signals is assessed by numericalcomputation of its radar cross section(RCS). High compute speed (Fig 1),necessary for such an electrically largeproblem, is achieved using using theintrinsic parallelism of graphics processingunits (GPUs).

GPU Accelerated Computation of Wind Turbine Radar Cross-Sections

Michael Robert McGlynnSchool of Computing, Mathematics and Digital Technology

Manchester Metropolitan University

Supervisors: CG Mingham, DM Causon, A Brown


Academics in the field of high performance computing, specifically applied to electromagnetics.


industry?

This research will provide the industry with a moreaccurate description of the RCS of a wind turbine.The model could be used as a tool to analyse thechanges in RCS of a wind turbine incorporatingradar absorbing material.


The results will help assist in the planning stages of awind farm by consulting on the impact wind turbineshave on radar operations. The results will also allowfor benchmarking of future computation of largescale problems implemented on parallel GPUs.

So far the SPEM method has been verified by comparisons with the classical Finite Difference Time Domain (FDTD) method in both 1D (Fig 2) and 2D. The RCS of a perfectly electrically conducting cylinder (PEC) was calculated numerically using a combination of the FDTD method and a near-to-far-field transformation (Fig 3)



Development of an accurate numerical solution this large scale problem uses the Smoothed Particle Electromagnetics Method (SPEM) particle based and massively parallel GPU computing.

Figure 1. Comparison between 1D FDTD and the SPEM methods.

Figure 2. Comparison between numerical and exact RCS results relating to the electromagnetic scattering from a PEC cylinder.

Michael [email protected]

Figure 3. Compute time comparison between serial CPU and parallel GPU implementations.

Impact Modelling of wind farms

Modelling the Impact of Offshore Wind Farms on Radar

Dr Laith Rashid, Prof Anthony Brown Microwave and Communication Systems Research Group

The University of Manchester

To address the radar interference it is important tomodel these effects prior to the construction ofthe wind farm. Due to their size, modelling thescattering using commercially available tools acomputationally tedious task.

Marine Navigational Radar

Offshore wind farmscover large areas andmay have an impacton marine radarsoperating near thewind farm. Such effectmay include the

cluttering of the radar display due to high returnsfrom the wind farm and multiple reflections ofthe radar signal within the farm. This can be seenthe measurements in Figure 1a

Air Traffic Control (ATC) Radar

Wind turbines are largestructures that reflects a largeportion of the radar pulses. Thismay cause returns from smalltargets near the wind farm to belost within the wind farm clutter.

Additionally, ATC radars use Doppler processing todistinguish between static clutter and movingtargets. At certain illumination, the returns fromthe rotating blade may be similar to that of asmall aircraft. Measured Doppler signature isshown in Figure 1b.

Measured Vs Modelled Results

Figure 1 (a) Marine radar display near North Hoyle (b)Measured Doppler signature of the Swaffham (source: BWEA)

Figure 2 (a) Modelled radar display as shown in Fig 1a (b)Modelled Doppler signature of generic turbine (blades only)

Dr Laith Rashid+44 (0)161 [email protected]

Conclusions and Future Research

The developed modes show promising results thatare in good agreement with measured data.Future developments include modelling theinteraction with the local terrain and introducingpossible mitigation measures through stealthtreatment and data fusion. This may enable earlyidentification and resolving potential interferenceissues with radars.

This research aims to develop models to simulatethe impact of wind farms in a computationallyefficient manner. Scattering from the turbine asan entity and the farm in totality can be modelledusing unique meshing algorithms and simplifyingassumptions. Results are shown in Figure 2.

Issues addressed

Theme 3 is investigating offshore configuration and controlstrategies, and the offshore to onshore connection andtransmission scheme. Several possible scenarios are envisaged,with offshore wind farms and AC networks connected to shoreusing HVDC links (far offshore) and AC links (near offshore).

Several potential needs for storage are foreseen:•To enhance stability in the offshore AC network in the steadystate, and following external and internal disturbances andtransients•To avoid turbine trips due to offshore and onshore faults•To avoid curtailment of wind farm output

Impact of the research

Supergen WindTask 3.4 Integration of energy storage

Alan Ruddell, STFC Rutherford Appleton Laboratory, OX11 0QX

The research results will answer important questions:

•Is storage required offshore, and what are the benefits?•What are the requirements (esp. power and energy)?•What are the appropriate technologies?•How can storage be controlled to optimise the integrated system?•What will be the cost and lifetime?

The results will have an impact on the design of offshore networks,converters and control systems.

Approach

Results

Application Power Storage time Response Cycling Technology location

a) stability low -

medium

seconds sub-sec high supercapacitor,

flywheel

offshore

b) turbine

trips

high seconds - minutes sub-sec low flywheel,

battery

offshore

c) avoiding

curtailment

high hours slow low battery, flow

cell

onshore

The various scenarios envisaged in Theme 3 set the scene for investigation of the type, location and control strategy for energy storage, with the main focus on storage located offshore.

Research on integration of energy storage will include the following tasks:•Development of outline requirements specifications and assessment of applicable energy storage technologies for offshore applications.•Defining performance requirements and development of energy storage sub-system models.•Simulation of power systems, and investigation of strategies to enhance performance of the integrated system.

•a hybrid technology solution for a) and b) could be possible, to provide a range of cycling and power capability•a high energy solution for c) offers other services, e.g. arbitrage•a fast response solution for c) could also offer stability improvements

High-speedcomposite flywheel (UPT)

Li-ion battery module (Exide)

Outline storage requirements include definition of:•Power and energy•Response time•Charge and discharge rates•Cycling lifetime•Size, weight, and environmental specifications

Technologies identified are:

Supercapacitor75V power module (Maxwell Technologies)

Dr Alan RuddellSTFC Rutherford Appleton Laboratory01235 [email protected]

This initial data indicates that there is potential for siting ofwind turbines in or near to forested areas without largedetriment to normal operating performance. This enables abroadening of the scope within which wind turbines can beviably located.


Research is being conducted through the use of windtunnelmodelling (Fig.1) withLDAacquisition techniques.This is applied together with a novel approach tomodelling of forests in a wind tunnel environment usingdiscrete porous fences (Fig. 2). The use of this procedureallows for measurements to be conducted during the‘development’ phase of the flow through dense foliage.Combined with the subsequent interaction of the flowabove the porous fences, the research technique can beemployed to assess the modification to atmosphericboundary layer at wind turbine height above a forestedregions aswell asdownstream.




address?

Experimental analysis is being conducted into themodification of wind characteristics over forestedregions. The data obtained will yield an insight into thenature of the flow that could typically be encounteredby wind turbines located downstream or amongst suchareas.


industry?

Wind Flow Over Forested Terrain

Adam Sayer, Fluids Research GroupUniversity of Surrey

Wind turbine manufacturers, operators and developers alikemay find the results of particular interest. As furthermeasurements are made the results can be refined enablingall interested parties to determine the specific merits of sitingwindturbines in forested terrain.

Theresearch conducted canbeused in thecalculation of theflow characteristics and fatigue loads exerted on turbineblades due to modification of the flow from a range offorestedtreespecies.

What method does this research

use?

A brief selection of results from wind tunnel modelling (Fig. 3) suggests that whilst expected modification within and just above the 'forested’ region is observed, recovery above the canopy indicates little change to the average wind speed across a turbine rotor. However there is a notable increase in turbulence fluctuations in the lower half of the rotor height signifying a possible increase in blade fatigue.

Adam Sayer+44 (0)1483 [email protected]

Figure 1: EnfloWind Tunnel at the University of Surrey

Figure 2: Use of discrete porous fences to simulate rows of trees

Unmodified Boundary Layer Profiles

Typical 2MW Rotor Height Region

Typical Forest Height Region

Figure 3: Results for U/Urefand u’/U (x-axis) indicating the modification of the boundary layer within the working height of a 2MW wind turbine

Modified Profiles by Porous Fences



What issue does this

research address?


industry?

Wind Turbine Controllers A Technique for Delivering Synthetic Inertia

Adam Stock, Industrial Control Centre University of Strathclyde


research use?

Preliminary results of the first method show that it could be very effective for providing synthetic inertia, equalling and perhaps even exceeding the current inertia response provided by more traditional power plants.


This research builds on the Simulink models developed in Supergen stage 1. These models are used to develop a new controller that will allow the wind turbine to supply extra power when the grid frequency drops below a set level. Two methods are being investigated to achieve this. One involves adding additional torque to the torque demand controller and allowing the turbine to reduce speed – effectively converting some of the kinetic energy in the rotor into electrical energy. For the second method the turbine operates with a small pitch angle already in place. When the extra power is required the turbine alters the pitch angle and changes control strategy to supply extra power.

This Graph shows the frequency response of the grid with zero synthetic inertia (green), an “ideal” synthetic inertia (red) and the output with the controller used to generate synthetic inertia that has been developed during this research (blue)

Under a “Gone Green Scenario” there could be 29GW of wind generation by 2020, with the total renewable share expected to grow to up to 36%. One disadvantage of this is a reduction in natural grid inertia that is usually supplied by conventional plants, which in turn can lead to system security issues, whereby the grid frequency may drop too far too quickly during a sudden surge in demand or dip in supply. In order to combat this problem, this research is being conducted to find a novel controller based method for boosting grid frequency in the event of a surge in demand or drop in supply. This technique could allow wind turbines to fill the 36% of generation that is envisioned by 2020.

Adam Stock +44 (0)7730 586296 [email protected]

If the techniques developed by this research are shown to work it will allow energy firms to press ahead with the expansion of the wind energy sector without having to invest heavily in separate systems to provide system inertia. This technique could even be applied to existing turbines without any additional hardware.

Wind turbine developers and operators will both benefit from this research as it will allow Wind Turbines to contribute a larger share of total energy generation.

This results of this research will be able to be used to implement new control techniques for wind turbines to provide synthetic inertia.


address?

With the focus of the industry shifting tooffshore installations the desire for muchlarger wind turbines is growing.

This research will explore the potentialdesign limits that may be encountered aswind turbine designs become very large(>7.5MW).


industry?

Design Limits For Very Large Wind Turbines

David Thompson, University of Strathclyde


Wind Turbine Manufacturers and Developers andmembers of the research community.

What results are expected?


research use?

Integration of the Structural Loads andMaterials Theme of Phase 1 and acomprehensive assessment of design limitsas the devices are scaled up.

David [email protected]

The final objective of this project is a criticalassessment documenting potential turbinedesign limits and an assessment of currentmodels and design tools.

By identifying turbine design limitations anddeveloping the current design tools andtechniques the industry will be better equippedto produce much larger turbines. Incentives forincreasing turbine size are largely economicalwith the appeal of achieving an optimum specificcost of energy. The optimum specific costs foroffshore installations is pushed towards bladediameters of around 80m because of the addedcosts of subsea foundations and power take-off.


Knowledge of the limits of the current technologycan be used to help direct future research in thestructural mechanics and dynamics and thecontrol design of turbines.

Reference: W. E. Leithead: Wind Turbine Scaling and Control, Supergen 2nd Training Seminar

Periodic air-gap variation as a function of the BPF

0.3 0.2 0.1 0.0 0.1 0.2 0.3

0.02

0.04

0.06

0.08

0.10

0.12

0.14

rotor displacement

eccentr

icity

This work is focused on investigating wind turbinedoubly-fed induction generator electrical andmechanical fault detection. This research aims toidentify spectral fault signature in the machineelectrical signals in order to achieve non-invasive

fault detection.


industry?


address?

Wind Turbine Generator Condition MonitoringDr Damian Vilchis, Dr Sinisa Durovic & Professor Sandy Smith,

Power Conversion GroupThe University of Manchester

On-going researchCurrent work involves the development of conditionmonitoring techniques for detection of incipient rollingbearing faults. The mathematical model is being extendedto incorporate the ball pass frequency (BPF) over a bearingrace defect thus allowing the simulation and detection ofthe BPF related harmonic frequencies for a DFIG. The testrig is undergoing modifications in order to enableexperimental research of bearing fault effects. Mechanicalfault detection in other generator types (Direct-drivePM/Wound field SG) will also be investigated.

The identified fault detection principles can be embeddedin a condition monitoring system (CMS) to improve theoperating cost, availability and reliability of windgenerators. CMS plays a pivotal role in establishing acondition-based maintenance and repair policy, which canbe more beneficial than corrective and preventivemaintenance.


research use?

- Winding and brushgear fault specific spectralcomponents are identified in the current and powersignals.- Analytical expressions are derived that link the faultfrequencies to the generator operating conditions. Theexpressions enable real time monitoring of faultfrequencies of interest for variable wind conditions.


The research is based on a generator model that isverified by experimental results. The model employscomplex conductor distribution theory and canaccommodate arbitrary winding/brushgear faults. Apurpose built laboratory DFIG test rig is used forexperimental research and model validation.


Wind Turbine Manufacturers, Operators and CMSDevelopers.

0 100 200 300 400 500 600 700 800-60

-50

-40

-30

-20

-10

0

Frequency [Hz]

Nor

mal

ized

spe

ctru

m [d

B]

MODEL

RIG

273.8 Hz

373.8 Hz597.6 Hz

697.6 Hz150 Hz

250 Hz 350 Hz

450 Hz

0 100 200 300 400 500 600 700 800-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

Frequency [Hz]

Nor

mal

ized

spe

ctru

m [d

B]

MODEL

RIG

112 Hz

212 Hz

150 Hz

373.8 Hz

435.7 Hz

273.8 Hz

535.7 Hz

597.6 Hz

697.6 Hz

250 Hz 350 Hz

Healthy machine Stator open-circuit fault

DFIG stator current spectrum

Brushgear fault was introduced at ≈15 sec

Measured stator current spectrum for variable speed operation

ContactDamian.Vilchis-rodriguez @manchester.ac.uk

[email protected]

[email protected]




address?

Condition monitoring for modern largewind turbines, particularly in the offshoreenvironment, to detect and identify WTdrive train faults .


industry?

Condition Monitoring Using the Wind Turbine Generator Control Loop

Mahmoud Zaggout, New & Renewable Energy GroupDurham University

WT condition monitoring system Manufacturers,Operators and Developers.

Conventional condition monitoring techniquesrequire the deployment of a variety of costlysensors and computationally intensive analysistechniques. In this research, the monitoring basedon observing the current or voltage signals ofcontrol loops. These signals are available at nocost, requiring no new sensors.

Mahmoud Zaggout+44 (0)191 33 [email protected]

The results allow to improve the current conditionmonitoring system performance and reduce thecost.


research use?

This research will focus on; firstly, understandthe generator control loop in a WT anddetermine which signals are most likely toyield monitoring signals which will determinecondition and the deterioration of condition.Secondly, simulation will be carried out of areal large wind turbine using Matlab.Representative faults will be applied and theeffects on the control loop signals observed.Thirdly, A comprehensive model of the 30 kWTest Rig established in the school will beconstructed in Matlab and Labview to monitorthe wind turbine drive train. Then, develop theTest Rig to close loop and representative faultswill be applied and observed. Finally, developthe real Test Rig into a closed loop and testingthose theories experimentally.


10-1

100

101

102

103

10-8

10-6

10-4

10-2

100

102

Frequency (Hz)P

SD

(P

ow

er

pe

r H

z)

Measured

Simulated

121.3 Hz

0.30 Hz

0.35 Hz

22.90 Hz

23.20 Hz

121.62 Hz

Figure 1: A future diagrammatic representation of the Test Rig

Figure 2: Torsional PSD for experimental Test Rig and its Matlab model

Experimental investigation of electrical andmechanical faults by Durham University testrig. The rig is designed with components andcharacteristics similar to those of operationalWT drive trains and comprises a 4-pole, 30kWwound rotor induction generator driventhrough a 5:1 gearbox by a 54kW DC motor.The rig is equipped with SKF WindCon 3.0, acommercially available CM system.

The aim of this research is to program intoWindCon an iterative localised discrete Fouriertransform (IDFTlocal) algorithm [1] for fault-related frequency detection.

Figure 1. WindCon process overview of Durham test rig . a) Woundrotor induction generator; b) Experimental balance planes; c)Gearbox; d) DC motor.

WindCon diagnosis usually requires the manualinvestigation of faults by experienced CMengineers. The incorporation of refined frequencytracking techniques into this CMS would result inan increasing degree of automation in the analysisof non-stationary, variable speed and load signalsgenerated by WTs, reducing the man-power costs.This is one of the major challenges for the reliabledevelopment of large offshore wind farm.

WindCon ability of online automatic detection of 3fault-like conditions on the test rig:

o Rotor electrical asymmetryo High speed mass unbalanceo Gear tooth failure

Eliminate the need for post-processing ofmonitored signals in the IDFTlocal algorithm.




address?

The automation of condition monitoring (CM)and diagnostic techniques for early detection ofincipient faults in wind turbine (WT)components. This allows to take remedial actionprior to the point of catastrophic failures,optimizing the performance of WT.


industry?

WT Turbine Manufacturers, Operators andMaintenance Management Staff. Developers ofWT CMSs.

Main implications for offshore WTs are thereduction of downtime, hence the increase ofavailability, by applying Condition-BasedMaintenance (CBM) strategies based on the useof effective and reliable CM systems.

PhD Research StudentDonatella Zappalá+44 (0)191 33 [email protected]

Automation of Wind Turbine Condition Monitoring

Donatella Zappalá, New & Renewable Energy GroupDurham University


research use?

What results are expected?

References:[1] Crabtree, C. J., Condition Monitoring Techniques for Wind Turbines,PhD Thesis, Durham University, November 2010.

Who can use and How can

use this research result?


result address?

Who to contact?

The current challenge faced by structuraldesigners is becoming increasingly difficult as theimposed design criteria of wind turbine bladesrequires to reduce the manufacturing cost ofblades without sacrificing their fatigue resistanceperformance. Therefore, novel materials andrapid manufacturing techniques have become themain driving forces in the wind turbine bladeindustry. In this research, composites materialsmade by 2D stitching and 3D textiles weavingtechniques were compared to conventional non-crimp fabrics (NCFs). In order to maximize theadvantages of 2D-stitched and 3D-woven fabricswithin the low-cost vacuum assisted resin infusionprocess, a rapid one-shot infusion process wasalso developed.

Impact of this research

result to the wind industry?

Research outputs for industrial applicationwww.supergen-wind.org.uk

Cost-effective manufacturing wind

turbines with novel materials

Chi Zhang Paul HoggNorthwest Composites Centre, University of Manchester

This research result can be used by manufacturersand developers of Wind Turbine Blades. Moredetails of our research outputs includingpublications can be found on the Supergenwebsite.

Fig 3. Design of one-shot vacuum assisted resin infusion process

Professor Paul Hogg Head of the school of materials+44 (0)161 306 3551 [email protected]

Chi Zhang Research Associate+44 (0)161 275 8167 [email protected]

Inlet

outlet

Fig 2. Fatigue properties of 3D woven composites on the warp direction after tension-tension fatigue

20

30

40

50

60

70

80

90

100

10 100 1,000 10,000 100,000 1,000,000 10,000,000

Load Cycles to Failure

Str

es

s L

ev

e/%

F003

F004

F006

F018

2D plain woven

3D angle-interlocked

3D layer-to-layer (hybrid)

3D layer-to-layer

R=0.1

Fig 1. Tomography images of unstitched (left) and stitched(right) samples tested after 15,000 fatigue cycles (justbefore the sample failed) under the maximum fatiguestress of 382.9MPa.

Interlaminar cracks and delaminations

Resin-riched area around stitch

Manufacturing an integral wind turbine blade byusing 3D weaving techniques together with rapidcuring process, such as Quickstep® and infraredheating, can increase the production rate andhence reduces the cost. Currently, our main workis focused on the development of 3D-wovenpreforms for the shear web and jointing areas.

Future work

Wind turbines are fatigue-

critical machines

Wind turbines are fatigue-critical machinesthat require comprehensive and detailedanalyses on the fatigue issues and the failuremechanism to guarantee the wind turbinesrunning under normal operating conditionsand the wind turbine blade is mainly made upof composite materials, thus furtherunderstanding and more research needs to bedone concerns to the fatigue issues ofcomposite. Current research focuses on thetension fatigue and torsion fatigue properties..

Impact of this research to

the wind industry

Fatigue issues of ± 45° glass fibre/epoxy composite for wind

turbine bladesKuangyi Zhang Paul Hogg

Northwest Composites Centre, University of Manchester

Testing procedure

Composite samples were manufactured byusing vacuum assisted resin infusion process.Apply both static and cyclic tensile andtorsional loads on the 45° glass/epoxycomposite coupons. Calculate the tensilestrength and torsion rigidity, count the numberof cycles to failure.

Kuangyi Zhang

+44 (0)161 306 [email protected]

Results &discussions

y = -13.138x + 94.751

y = -2.6499x + 53.915

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7

Str

ength

%

Log(N)

+/-45 Glass/Epoxy

liner trend line

-10

0

10

20

30

40

50

60

70

80

0 1 2 3 4 5 6 7

Str

ength（

%）

LogN

+/-36 degree

+/-27 degree

+/-18 degree

+/-9 degree

+/-36 degree

+/- 27 degree

+/-18 degree

+/-9 degree

1.There is a limit point for the fatigue properties of±45° glass/epoxy composite when applied cyclictension load. The composite shows better fatigueproperties before the limit than after the limits.2.The cyclic torsional load has accelerated thefailure of the specimen when applied both torsionand tension fatigue under same frequency andsame phase. Furthermore, the number of cycles tofailure decreases as the twist angle of torsioncyclic load increase gradually.

Testing equipments

Instron® hydraulic fatigue testing machines.

More tests will be processed in other composite

materials, e.g. ±45°/0°, 3D, woven and 2D glass

fibre reinforced with epoxy resin.

LMGJ t

• Torsional rigidity, GJ (ref: [1])

xy

zx

k

xy

G

G

h

bc

c

k

k

ccc

bhcGGJ

...5,3,14

2

3

2tan

21

32)(

)(

= TorquetM

= twist angle (rad) per unit length (ω = πθ/180)

L = length of coupon (between clamps)

b = width of coupon

h = thickness of coupon

zxxy GG / = In-plane and out-of-plane shear moduli

[1] S.G. Lekhnitskii, Theory of elasticity of an anisotropic elastic body, Holden-Day, Inc., San Francisco (1963) p. 197–205.

This interesting results of the combination oftension fatigue and torsion fatigue show that thefracture mechanism of blade composite is veryimportant when we try to get the optimisticefficiency and proper lifetime of the wind turbine.




address?

The wake of a wind turbine produces avelocity deficit and higher turbulence intensitywhich affects the performance and loads ofdownstream machines. For wind farmoptimization, it is vital to understand thedevelopment and interactions of the wakesunder various conditions, including stable andunstable conditions


industry?

Wind Tunnel Simulation of Wake Interaction

Shanying Zhang and Philip E Hancock, EnFlo laboratoryUniversity of Surrey

Wind farm developers, designers, andresearchers in the wind energy industry.

With experimental data, various analyticalmodels and CFD schemes can be validated forpredicting the wake dynamics within offshorewind farms. Besides, the detailed experimentalresults will improve our understanding of thephysics of the wake interactions, and how theireffects can be minimized.

Dr Shanying Zhang+44 (0)148 368 [email protected]

This project will produce a reliable database forwind farm designers and researchers to validatetheir models in predicting wind farm efficiency.


research use?

Wake flow of single wind turbine at a neutral stratified atmospheric boundary layer


Wind tunnel simulation is being employed toreproduce various atmospheric boundarylayer conditions. Arrays of scaled-down windturbine models (1:300) will be investigated.The Enflo wind tunnel is a unique nationalfacility.

A matrix of wind turbines (3x3 or 3x4) will betested at neutral, stable and unstableatmospheric boundary conditions.

What is the next step?

Documents

Supergen Wind 2011 General Assembly poster list · PDF fileSupergen Wind 2011 General Assembly poster list 1. ... Wind Turbine Wake Modelling 10. ... and temperature probes to measure