ENERGY Load Measurements on floating offshore … for web/SMI S Presentasjonar...Load Measurements...

DNV GL © 2014 SAFER, SMARTER, GREENERDNV GL © 2014 Lofot - Load Measurements on floating offshore turbines /2015-04-16.ppt

ENERGY

Load Measurements on floating offshore Wind TurbinesChallenges with Respect to IEC 61400-13

1

Dipl.-Ing. Hans-Peter Link

DNV GL © 2014

Industry consolidation

2

DNV GL © 2014

Load Measurements on floating offshore Wind Turbines (LofoT)

Current CommonProcedure

Effects of Floating Structure to

- Instrumentation- Procedures- Data analyses

Data Analyses And

UncertaintiesConclusion

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Data Analyses And


Load-Measurements Load-Simulation

Measurements for validation of numerical tools

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Aerodynamic impactNo meteorological mast available Data classification into

wind speed bins Data classification into

turbulence intensity bins Determination of wind

direction and connected filter-criteria

Air density due to missing air pressure and air temperature information

Hydrodynamic impact An Impact to consider in

addition to WS and TI? 3 dimensional Capture

Matrix? Ws TI Wave height Current speed?

Movement in 6 dof For recording of

turbine behavior adaption of instrumentation necessary

Will effect procedures for determination of calibration factors

Additional longitudinal forces

Effect of floating structure to procedure of load measurements:




Data Analyses And


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Aerodynamic impactNo meteorological mast available Wind speed and

Turbulence Intensity Data classification

into wind speed bins Data classification

into turbulence intensity bins

Wind direction Determination and

connected filter-criteria

Air density due to missing air

pressure and air temperature information

Nacelle based LiDAR

Floating LiDAR

Nacelle Anemometry

Wind speed:

• Tilt-Angle• Roll-Angle• Volume

• Distance WEC-LiDAR

• Angle of LiDAR-Beam

• Nacelle-Effects

TurbulenceIntensity:

Increase of uncert.Volume Measure>>Uncert.

Increase of Uncert. due to Volume Measurement

Increase of Uncert.




Data Analyses And


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Data Analyses And


TI vs. Power TI vs. wind speed

TI vs. timeNacelle LidAR on WINDFLOAT

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Nacelle based LiDAR

Floating LiDAR

Nacelle Anemometry

Wind direction: • Directmeasurement of Yaw-Misallignment

• WD to correct with orientation and position of buoy

• Wind vane effected by nacelle and rotor




Data Analyses And


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Nacelle based LiDAR

Floating LiDAR

Nacelle Anemometry

Air Pressure and air temperature

• Effected by Nacelle

• Air Pressure and air temp. correct

• Wind vane effected by nacelle and rotor




Data Analyses And


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Movement in 6 dof Instrumentation• Gyroscope and Inclination-Sensors for monitoring

• Heave / Surge / Sway• Pitch / Roll / Tilt

• Dual differential GPS for monitoring • Position• orientation

• Additional measures to be monitored• Longitudinal forces• Floater-Signals (e.g. Mooring lines, strain gauges, …)

ProceduresCommon procedures are effected by 6 DOF:• Pitch-Rotation for determination of calibration factors• Yaw-Rotation for determination of calibration factors• …

Data-Analyes• Additional effects will reflect in additional uncertainties• …




Data Analyses And


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Data Analyses And


Hydrodynamic impactStorm “Britta” – 2006-11-01

FINO 1+20 m C.D.

C.D. = LAT

Lowerplatform +15 m C.D.

10 m

20 m

0 m

Hs = 9.77m

Hmax~16 m

Obvious Relevance

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Data Analyses And



FINO 1+20 m C.D.

C.D. = LAT


10 m

20 m

0 m

Hs = 9.77m

Hmax~16 m

Wavebuoy

ADCP(ground based)

ADCP(horizontal)

Wave Radar

Waveheight X X X X

Wavedirection X X - X

CurrentSpeed X X X -

CurrentDirection X X X -

Changing distance and direction to

Floater

Changing distance and direction to

Floater

Changing orientation

Changing orientation

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Instrumentation• Wave height• Wave direction• Current speed• Current direction• …

Procedures to be defined for • Bin-Classification of hydrodynamics

• Ws-bins• Wave-frequency-bins

• …

Data-AnalysesHow to consider hydrodynamic impact in addition to aerodynamic impact• 3rd dimension next to WS and TI

3 dimensional Capture Matrix (ws, TI, Ws)? 4 dimensional Capture Matrix (ws, TI, Ws, Wf)?

• …




Data Analyses And

UncertaintiesConslusion


FINO 1+20 m C.D.

C.D. = LAT


10 m

20 m

0 m

Hs = 9.77m

Hmax ~16 m

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Data Analyses And


Data Analyses

How to use measurements for validation of numeric models?

Analyses of additional measures• Hydrodynamics

• Wave height (significant wave height)• Wave direction• Current speed• Current direction

• Aerodynamics• E.g. rotor aquivalent wind speed

• Floater• E.g. tension of mooring lines

• Turbine• E.g. longitudinal forces

Adaption of procedures to floating situation Aerodynamic impact

• Determination or/and correction of TI / WS / rotor equivalent ws Hydrodynamic impact

• consider hydrodynamic impact in addition to aerodynamic impact 3 dimensional Capture Matrix (ws, TI, Ws)?

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Data Analyses And


Uncertainies Evaluation of uncertainties• Additional aspects

• No met mast• Different procedures

Procedure for uncertainty-evaluation to be• Reviewed under consideration of measuring and simulating aspects

• E.g. definition of TI• E.g. defining measuring program

• …

Additional measures in one equation will result in increase of uncertainties

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Data Analyses And


Load-Measurements Load-Simulation

Measurements for validation of numerical tools

How to use measurements for validation of numerical models

Adjustment of Measurements and/or Model

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Data Analyses And


Adaption ofInstrumentation

Adaption ofProcedures

Adaption ofAnalyses

Evaluation of Uncertainties

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Measurementsfor

Model Validation

accurate / affordable / reliable

DNV GL Certification

DNV GL Measurements

Turbine Manufacturer

Floater Manufacturer





Data Analyses And


AdaptionofInstrumentation

Adaption ofProcedures

Adaption of Analyses

Evaluation of Uncertainties

Standards &

Guidelines

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Continuous monitoring of the structural integrity and periodical inspections on offshore wind turbinesContinuous monitoring of the structural integrity and periodical inspections on offshore wind turbines

Copyright: Elsam A/S




Data Analyses And


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SAFER, SMARTER, GREENER

www.dnvgl.com

Thanks for your attention!

15 April 2015Private and confidential

20

Dipl.-Ing. Hans-Peter Link Deputy Section Head, Loads & Power PerformanceDNV GL - Renewables Advisory

E-mail [email protected] +49 160 4713041 | Direct +49 4856901 46

ENERGY Load Measurements on floating offshore … for web/SMI S Presentasjonar...Load Measurements...

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