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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
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plit
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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.
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
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100
150
200
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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
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Filtered Result
Balanced Rotor 23% Asymmetry 46% Asymmetry
(a)
(b)
0 50 100 150 200 250 300 350 400 450102
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104
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106
Fre
qu
en
cy [H
z]
Result from Iterative DFTlocal
(Calculation Time = 1.016s (0.22883%))
Fault Frequency, ff
0 50 100 150 200 250 300 350 400 4500
5
10x 10
4
Am
plit
ud
e
Amplitude of Fault Frequency
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?
What results were found?
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]
Result from Iterative DFTlocal
(Calculation Time = 0.969s (0.21824%))
Fault Frequency, f
f
0 50 100 150 200 250 300 350 400 4500
50
100
Am
plit
ud
e
Amplitude of Fault Frequency
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]
Result from Iterative DFTlocal
(Calculation Time = 0.953s (0.21464%))
Fault Frequency, f
f
0 50 100 150 200 250 300 350 400 45040
60
80
100
Am
plit
ud
e
Amplitude of Fault Frequency
0 50 100 150 200 250 300 350 400 45040
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Am
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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
What issue does this research
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
What results were found?
turbulent different, replicating the varying conditions we
seeinthereal world.
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20
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gra
l Le
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th S
cale
(m
m)
0.05
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0.15
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rbu
len
ce I
nte
nsi
ty,I
u (
%)
Mesh size
100mmMesh size
50mm
0
10
20 40 60
Inte
gra
l Le
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th S
cale
(m
m)
Streamwise Location (x/Mesh size)
0
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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.
Impact of this research to the wind
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.
Impact of this research to the wind
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
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
-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
How can the research result be used?
Who can use the research results?
What issue does this research
address?
Impact of this research to the wind
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.
What method does this
research use?
What results were found?
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
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-1
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0
0.5
1
1.5
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-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.
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]
What issue does this research
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,
What results were found?
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
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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.
How can the research result be used?
Who can use the research results?
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
How can the research result be
used?
Who can use the research results?
What issue does this research
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
What results were found?
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?
Who can use the research results?
What issue does this research address?
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.
What method does this research use?
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.
What results were found?
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.
What method does this
research use?
What results were found?
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
Rotor Side Converter
0.00 0.50 1.00 1.50 2.00 ...
...
...
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-2.0
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0.0
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y (
kA
)
ir_d (kA) ir_q (kA)
-3.0
-2.0
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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
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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
Offshore Networks ConnectionAntonio Luque, Institute for Energy and Environment
Strathclyde University
What issue does this research address?
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
What method does this research use?
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
What issue does this research
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
Who can use the research results?
Academics in the field of high performance computing, specifically applied to electromagnetics.
Impact of this research to the wind
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.
How can the research result be used?
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)
What results were found?
What method does this research use?
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.
What results were found?
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.
How can the research result be used?
Who can use the research results?
What issue does this research
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.
Impact of this research to the wind
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
How can the research result be used?
Who can use the research results?
What issue does this
research address?
Impact of this research to the wind
industry?
Wind Turbine Controllers A Technique for Delivering Synthetic Inertia
Adam Stock, Industrial Control Centre University of Strathclyde
What method does this
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.
What results were found?
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.
What issue does this research
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).
Impact of this research to the wind
industry?
Design Limits For Very Large Wind Turbines
David Thompson, University of Strathclyde
Who can use the research results?
Wind Turbine Manufacturers and Developers andmembers of the research community.
What results are expected?
What method does this
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.
How can the research result be used?
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
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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.
Impact of this research to the wind
industry?
What issue does this research
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.
What method does this
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.
What results were found?
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.
Who can use the research results?
Wind Turbine Manufacturers, Operators and CMSDevelopers.
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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
How can the research result be used?
Who can use the research results?
What issue does this research
address?
Condition monitoring for modern largewind turbines, particularly in the offshoreenvironment, to detect and identify WTdrive train faults .
Impact of this research to the wind
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.
What method does this
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.
What results were found?
10-1
100
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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.
How can the research result be used?
Who can use the research results?
What issue does this research
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.
Impact of this research to the wind
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
What method does this
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?
What issue does this research
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
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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
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ength
%
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liner trend line
-10
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ength(
%)
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+/-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.
How can the research result be used?
Who can use the research results?
What issue does this research
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
Impact of this research to the wind
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.
What method does this
research use?
Wake flow of single wind turbine at a neutral stratified atmospheric boundary layer
What results were found?
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?