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3/186EWEA 2014 Scientific Proceedings

1Scientific Proceedings

Publisher:

European Wind Energy Association (EWEA)

Responsible:

Tim Robinson,

Rue dArlon 80, B-1040 Brussels, Belgium

Tel: +32 2 213 1811 Email: [email protected]

Printed by:

Open print 9 782930 670072



2

Scientific committee

Mnica Arags,CITCEA-UPC, Spain

Sandrine Aubrun,Universit dOrlans, PRISME Laboratory, FranceGunther Auer,Acciona Energa, Spain

Marta Barreras,Gamesa, Spain

Kim Branner, Technical University of Denmark, Denmark

Feargal Brennan, Cranfield University, United Kingdom

Panagiotis Chaviaropoulos,CRES, Greece

Christopher J. Crabtree, University of Durham, United Kingdom

Alvaro Cuerva, Universidad Politcnica de Madrid, Spain

Geoff Dutton, STFC Rutherford Appleton Laboratory, United Kingdom

Agusti Egea-Alvarez, CITCEA-UPC, Spain

Sugoi Gomez-Iradi, CENER, Spain

Emilio Gomez-Lazaro, Universidad de Castilla-La Mancha. Renewable Energy Research Institute, Spain

Oriol Gomis-Bellmunt, CITCEA-UPC, Spain

Francesco Grasso,Energy Research Centre of The Netherlands, The NetherlandsSven-Erik Gryning,Technical University of Denmark, Denmark

Gerrit Haake,AREVA Wind GmbH, Germany

Martin Hansen, DTU Wind Energy, Denmark

Detlev Heinemann, University of Oldenburg, Germany

Jessica Holierhoek,Energy Research Centre of The Netherlands, The Netherlands

Andrs Honrubia-Escribano, Renewable Energy Research Institute, Spain

Melero Julio Javier, Fundacin CIRCE, Spain

Athanasios Kolios,Cranfield University, United Kingdom

William Leithead, University of Strathclyde, United Kingdom

Denja Lekou,CRES, Greece

Hristo Lilov,Fraunhofer IWES, Germany

Cornelis Lindenburg, Energy Research Centre of The Netherlands, The Netherlands

Helge Aagaard Madsen, DTU Wind Energy, Denmark

Jakob Mann, DTU Wind Energy, Denmark

Marcia Martins, Alstom Renwables, Spain

Denis Matha, University of Stuttgart, Germany

Caas Miguel, Universidad de Castilla-La Mancha, Spain

Angel Molina-Garcia,Universidad Politcnica de Cartagena, Spain

Stavros Papathanassiou,National Technical University of Athens, Greece

Antoine Peiffer, Marine Innovation and Technology, United States

Joachim Peinke, University Oldenburg, Germany

Wojciech Popko, Fraunhofer IWES, Germany

Vasilis Riziotis, NATIONAL TECHNICAL UNIVERSITY OF ATHENS, Greece

Alan Ruddell, STFC Rutherford Appleton Laboratory, United Kingdom

Javier Sanz Rodrigo, CENER, Spain

Peter Schaumann, ForWind - Leibniz University Hannover, Germany

David Schlipf, Universitt Stuttgart, Germany

Martin-Martinez Sergio,Renewable Energy Research Institute, Spain

Carlos Simao Ferreira,Delft University of Technology, The Netherlands

John Dalsgaard Srensen,Aalborg University, Denmark

Niels N. Srensen, DTU Wind Energy, Denmark

John Olav Tande, SINTEF, Norway

Garcia Tania,E.I.I., Castilla la Mancha University, Spain

Peter Tavner, Durham University, United Kingdom

Sokratis Tentzerakis, CRES, Greece

Gijs van Kuik, Delft University of Technology, The Netherlands

Zsolt Viharos, Hungarian Academy of Sciences, Hungary

Axelle Vire,Delft University of Technology, The Netherlands

Spyros Voutsinas, National Technical University of Athens, Greece

Simon Watson, Loughborough University, United Kingdom

Christof Wehmeyer, Ramboll, Denmark

Marcel Wiggert, Fraunhofer IWES, Germany



3

On behalf of the European Academy of Wind Energy

(EAWE) and the European Wind Energy Association

(EWEA), we are pleased to present the Proceedings

of the Science & Research Track of the EWEA 2014

Conference in Barcelona.

EWEAs annual conference has included a Science

& Research Track since 2007. This track provides a

platform for scientists and engineers to present their

latest results and methods, and to engage in in-depth

technical discussions and the exchange of ideas

with their peers and industry. It demonstrates that

European wind energy research is far from academic,

but instead a lively discipline that supports the

industry in developing novel competences and relevantsolutions, while adhering to strict scholarly standards.

Novelty, care for detail, and scientific excellence

characterise these sessions.

As in previous years, the track showcases highlights of

current academic thinking about wind energy, both from

leading international experts as well as from a new

generation of upcoming young researchers. In reaction

to feedback from the EWEA 2013 Science & Research

Track, the call for abstracts was broader this year, and

sessions were then structured around the received

contributions. A novelty this year is the inclusion oftwo sessions dedicated to fixed and floating support

structures, respectively, reflecting the growing

importance and interest in these subjects.

The sessions this year are:

Aspects for offshore and complex terrain

How does the wind blow behind wind turbines and

in wind farms?

Aerodynamics and rotor design

Advanced control concepts

Whole-life foundation and structure integrity

Floating wind turbines

Electrical aspects and grid integration

Innovative concepts for drive train components

Advanced operation & maintenance

These proceedings include the full papers of all oral

presentations given during the conference sessions;

these were selected due to their novelty, relevance

and interest to a general audience. In addition, a

scientific poster session has been organized for works

of a more technical nature. The full papers of both

the oral presentations and of all posters from the

Science & Research Track are also available in theonline proceedings at: www.ewea.org/annual2014/

conference/conference-proceedings/

EAWE is responsible for the scientific content, the

review process, and the chairing of sessions in the

Science & Research Track. All papers were peer-

reviewed by a Scientific Committee, consisting of

scientists from EAWE member institutes and their

associates. The peer-review process had two steps:

a review of the extended abstract by at least two

experts, and a review of the full paper by at least one

of these experts. This procedure required skill, effortand discipline from both authors and reviewers. We

thank all authors for their willingness to take part in

the procedure, and the reviewers for their hard work

alongside their daily business.

EWEA is responsible for the organisation and

logistics of the conference, and we thank their highly

professional staff and their associates for the excellent

collaboration.

Prof. Dr. Michael Muskulus,Norwegian University of Science and Technology (NTNU)EWEA 2014 Track Chair: Science & Research and Editor of the EWEA 2014 Scientific Proceedings

President of the European Academy of Wind Energy (EAWE)

Prof. Dr. Jakob Mann,Technical University of Denmark (DTU)Editor of the EWEA 2014 Scientific Proceedings

Vice-President of the European Academy of Wind Energy (EAWE)

Foreword

Organised by: Review and selection of papers:



4

Table of contents

Aspects for offshore and complex terrain

S1.1 COMPLEX TERRAIN WIND RESOURCE ESTIMATION WITH THE WIND-ATLAS METHOD:

PREDICTION ERRORS USING LINEARIZED AND NONLINEAR CFD MICRO-SCALE MODELS .................. 8

Ib Troen, DTU, Denmark

S1.2 MESOSCALE MODELLING OF THE UK OFFSHORE WIND RESOURCE ............................................................... ............... 13

Simon Watson, Loughborough University, United Kingdom

S1.3 ON THE DETERMINATION OF STABILITY CONDITIONS OVER FORESTED AREAS

FROM VELOCITY MEASUREMENTS .......................................................... ................................................................... ........................................................... 18

Davide Medici, DNV GL - Energy, Italy

How does the wind blow behind wind turbines

and in wind farms?S2.1 QUANTIFYING THE IMPACT OF WIND SPEED ON WIND TURBINE COMPONENT FAILURE RATES ...... 23

Graeme Wilson, University of Strathclyde, United Kingdom

S2.2 WIND FARM LAYOUT OPTIMIZATION WITH WAKES FROM FLUID DYNAMICS SIMULATIONS .......... 28

Jonas Schmidt, Fraunhofer IWES, Germany

S2.3 LIDAR OBSERVATIONS OF INTERACTING WIND TURBINE WAKES

IN AN ONSHORE WIND FARM ................................................................. .................................................................. .................................................................. ..... 33

Matthieu Boquet, University of Colorado at Boulder, United States

S2.4 INSTRUMENTED DRONE MEASUREMENTS OF 3D FLOW STRUCTURE

OF MULTI-MW WIND TURBINES ........................................................... .................................................................. .................................................................. ..... 37

Ndaona Chokani, ETH Zrich, Switzerland

Aerodynamics and rotor design

S3.1 PRESSURE-VELOCITY ANALYSIS OF DYNAMIC STALL ON A VERTICAL AXIS WIND TURBINE ....... 41

Laurent Beaudet, Institut Pprime, UPR 3346 CNRS Universit de Poitiers ENSMA, France

S3.2 ESTIMATION OF WIND TURBINE MODEL PROPERTIES - TOWARDS

THE VALIDATION OF COMPREHENSIVE HIGH-FIDELITY MULTIBODY MODELS .................................................... 46

Carlo Bottasso, Technische Universitt Mnchen, Germany

S3.3 DESIGN OF LOW INDUCTION ROTORS FOR USE IN LARGE OFFSHORE WIND FARMS ........................... 51

Panagiotis Chaviaropoulos, CRES, Greece

S3.4 MEXNEXT-II: THE LATEST RESULTS ON EXPERIMENTAL WIND TURBINE AERODYNAMICS ............. 56

Koen Boorsma, ECN, The Netherlands



5

Table of contents

Advanced control concepts

S4.1 MECHANICAL LOAD ANALYSIS OF PMSG WIND TURBINES

IN PRIMARY FREQUENCY REGULATION .................................................................. ................................................................... ........................................ 61

Asier Daz de Corcuera, IK4-IKERLAN, Spain

S4.2 PROVIDING FREQUENCY DROOP CONTROL USING

VARIABLE SPEED WIND TURBINES WITH AUGMENTED CONTROL ............................................................ ............................. 68

Adam Stock, Strathclyde University, United Kingdom

S4.3 SENSORLESS CONTROL OF A POWER CONVERTER F

OR A CLUSTER OF SMALL WIND TURBINES .............................................................. ................................................................... ............................. 73

Agusti Egea-Alvarez, CITCEA-UPC, Spain

S4.4 SYSTEMATIC NUMERICAL DESIGN OF OPTIMAL BLADE PITCH CONTROL

FOR VERTICAL AXIS WIND TURBINES ............................................................. ................................................................... ................................................... 76

Markus Marnett, RWTH Aachen, Germany

Whole-life foundation and structure integrity

S5.1 DESIGN TOOLS AVAILABLE FOR MONOPILE ENGINEERING ............................................................ ................................................... 79

Paul Doherty, University College Dublin, Ireland

S5.2 CLASSIFYING RESONANT FREQUENCIES AND DAMPING VALUES OF AN OFFSHORE WIND

TURBINE ON A MONOPILE FOUNDATION FOR DIFFERENT OPERATIONAL CONDITIONS ........................ 83

Wout Weijtjens, Vrije Universiteit Brussel (VUB), Belgium

S5.3 KEY PERFORMANCE INDICATORS AND TARGET VALUES

FOR MULTI-MEGAWATT OFFSHORE TURBINES ......................................................... .................................................................. ............................. 88

Panagiotis Chaviaropoulos, CRES, Greece

S5.4 FATIGUE VERIFICATION IN WIND TURBINE FOUNDATIONS

APPLYING MARKOV MATRICES TO A FEM MODEL ......................................................... .................................................................. .................. 92

Angel Diez, MS-ENERTECH, Spain

Floating wind turbines

S6.1 WIND TUNNEL TESTS ON FLOATING OFFSHORE WIND TURBINES:

DESIGN OF A 6-DOF ROBOTIC PLATFORM FOR FLOATING MOTION SIMULATION ............................................ 97

Ilmas Bayati, Politecnico di Milano, Italy

S6.2 THE 5 MW DEEPWIND FLOATING OFFSHORE VERTICAL WIND TURBINECONCEPT DESIGN - STATUS AND PERSPECTIVE ............................................................................................................................................. 101

Uwe Schmidt Paulsen, Technical University of Denmark, Denmark

S6.3 MONOLITHIC CONCRETE OFF-SHORE FLOATING STRUCTURE FOR WIND TURBINES ........................... 107

Climent Molins, Universitat Politcnica de Catalunya, Spain

S6.4 STRUCTURAL INTEGRITY CONSIDERATIONS FOR THE H2OCEAN

MULTI MODAL WIND-WAVE PLATFORM ............................................................................................................................................................................ 112

Feargal Brennan, Cranfield University, United Kingdom

S6.5 LONG TERM MOORING LOADS ASSESSMENT ON A SEMISUBMERSIBLE WIND PLATFORM .............. 116

Raul Guanche, IH Cantabria, Spain



6

Table of contents

Electrical aspects and grid integration

S7.1 PLANS FOR SIGNIFICANT AMOUNT OF WIND POWER AND

VOLTAGE STABILITY OF THE DANISH ISLAND OF BORNHOLM ................................................................................................... 121

Vladislav Akhmatov, Energinet.dk Transmission System Operator of Denmark

S7.2 A COMPARISON OF DESIGN OPTIONS FOR OFFSHORE HVDC NETWORKS

THROUGH A SEQUENTIAL MONTE-CARLO RELIABILITY ANALYSIS ...................................................................................... 126

Callum MacIver, University of Strathclyde, United Kingdom

S7.3 EVALUATION OF A COMMUNICATION-BASED FAULT RIDE-THROUGH SCHEME FOR

OFFSHORE WIND FARMS CONNECTED THROUGH VSC-HVDC LINKS............................................................................... 131

Sotirios Nanou, National Technical University of Athens, Greece

S7.4 DEVELOPMENTS AND OPPORTUNITIES IN HVDC OFFSHORE GRIDS RESEARCH ....................................... 134

Olimpo Anaya-Lara, University of Strathclyde, United Kingdom

S7.5 ECONOMIC BENEFIT CALCULATIONS OF AN OFFSHORE WIND

AND ITS HVDC GRID DELIVERY SYSTEM IN NORTH AMERICA ................................................................................................. 138

Reynaldo Nuqui, ABB, United States

Innovative concepts for drive train components

S8.1 IMPROVED COST OF ENERGY COMPARISON OF PERMANENT MAGNET GENERATORS

FOR LARGE OFFSHORE WIND TURBINES ...................................................................................................................................................................... 141

Kerri Hart, University of Strathclyde, United Kingdom

S8.2 PROPOSED STRUCTURE FOR A HTS GENERATOR

FOR DIRECT DRIVE OFFSHORE WIND TURBINES...........................................................................................................................................

145Joseph Burchell, University of Edinburgh, United Kingdom

S8.3 DESIGN ASPECTS OF CORELESS AXIAL FLUX PERMANENT MAGNET GENERATORS

FOR LOW COST SMALL WIND TURBINE APPLICATIONS ....................................................................................................................... 149

Georgios Messinis, National Technical University of Athens (NTUA), Greece

S8.4 NEW BEARINGLESS GENERATOR WITH BUOYANT ROTOR

FOR LARGE DIRECT-DRIVE WIND TURBINES ............................................................................................................................................................ 154

Deok-je Bang, Korea Electrotechnology Research Institute, Republic of Korea

Advanced operation & maintenance

S9.1 ELECTRICAL FAULT DETECTION USING MECHANICAL SIGNALS ............................................................................................... 159Christopher Crabtree, Durham University, United Kingdom

S9.2 WIND TURBINE RELIABILITY ESTIMATION FOR DIFFERENT ASSEMBLIES, FAILURE

SEVERITY CATEGORIES AND ENVIRONMENTAL CONDITIONS USING SCADA DATA .................................. 162

Christos Kaidis, Uppsala University - MECAL B.V., The Netherlands

S9.3 TRAILING EDGE MONITORING WITH ACOUSTIC EMISSION DURING

A STATIC FULL SCALE BLADE TEST ...................................................................................................................................................................................... 168

Alexandros Antoniou, Fraunhofer Institute for Wind Energy Systems, Germany

S9.4 COMPARISON OF DATA-DRIVEN AND MODEL-BASED METHODOLOGIES OF

WIND TURBINE FAULT DETECTION WITH SCADA DATA ............................................................................................................................. 172

Zhenyou Zhang, Kongsberg Maritime AS, Norway

S9.5 PREDICTION OF WIND TURBINE GEARBOX CONDITION BASED ONHYBRID PROGNOSTIC TECHNIQUES WITH ROBUST MULTIVARIATE STATISTICS

AND ARTIFICIAL NEURAL NETWORKS ............................................................................................................................................................................... 177

Jamie Godwin, University of Durham, United Kingdom



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71

Figure12:Demandedan

dDeliveredChangeinPowerOutputFive5MW

Turbine(s)withaMeanWind

Speedof9.5m/sFollowingStrategy3

Table1:PercentageReductioninEnergyCaptu

re

WindSpeedDistributio

n

I(Mean10m/s)

II(Mean8.5m/s)

III(Mean7.5m/s)

Strategy

1

2

3

1

2

3

1

2

3

%ReductioninEnergy

Capture(2MW)

5.92

4.87

3.18

7.10

5.69

3.58

8.03

6.25

3.80

%ReductioninEnergy

Capture(5MW)

7.30

6.04

3.48

9.20

7.40

4.28

10.91

8.49

4.90

%ReductioninEnergy

Capture(Ave)

6.61

5.46

3.33

8.15

6.56

3.96

9.47

7.37

4.35

Table2:P

ercentageReductioninTowerDamageEquivalentLoads(DELs)

Wind

Speed

Distribution

I(Mean10

m/s)

II(Mean8.5m/s)

III(Mean7.5m/s)

Strategy

1

2

3

1

2

3

1

2

3

Turbulence

Profile

High

Low

HighL

ow

High

Low

High

Low

High

Low

High

Low

High

Low

High

Low

High

Low

%

Change

inDELs

(2MW)

-0.0

25

0.2

5

-0.4

7-0

.25

-0.4

5

-0.4

7

-0.0

26

0.3

3

-0.5

2

-0.2

5

-0.5

-0.5

2

-0.0

29

0.3

8

-0.5

5

-0.2

4

-0.5

2

-0.5

3

%

Change

inDELs

(5MW)

-0.3

8

-0.2

1

-0.6

5-0

.39

-0.5

4

-0.5

4

-0.4

5

-0.1

6

-0.6

9

-0.3

6

-0.5

9

-0.5

5

-0.4

6

-0.1

0

-0.7

0

-0.3

1

-0.6

0

-0.5

2

%

Change

inDELs

(Average)

-0.2

0

-0.0

2

-0.5

6-0

.32

-0.5

0

-0.5

0

-0.2

4

0.0

9

-0.6

1

-0.3

1

-0.5

5

-0.5

4

-0.2

4

0.1

4

-0.6

3

-0.2

8

-0.5

6

-0.5

3

Figure10:C

hangeinPowerOutputforFive5MWW

indTurbinesataMeanWindSpeedof13.75m/s

Figure11:Cha

ngeinPowerAcrossFive2MWW

indTurbinesataMeanWindSpeedof9.5m/sFollowing

Strategy2


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95

Figure11:LowerradialSteel

Maximumf

atiguedamage=1.3

475e-04

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