Integrated simulation challenges with the DeepWind floating vertical axis wind turbine concept D. Verelst, H.A. Madsen, M. Borg, U.S. Paulsen, H.G. Svendsen, P.A. Berthelsen 12th Deep Sea Offshore Wind R&D Conference EERA DeepWind’2015
DTU Wind Energy, Technical University of Denmark
Outline • Context • Simulation tool • Design Approach • Integrated Simulation Challenges • Future Design Cycles • Conclusions
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DTU Wind Energy, Technical University of Denmark
Context
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Need to lower the cost of offshore wind energy
Novel Designs
Challenges for current simulation tools
DTU Wind Energy, Technical University of Denmark
Simulation Tool
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Aerodynamics
Hydrodynamics
Mooring dynamics Structural dynamics
Controller-generator dynamics
HAWC2
DTU Wind Energy, Technical University of Denmark
Simulation Tool
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Aerodynamics
Hydrodynamics
Mooring dynamics Structural dynamics
Controller-generator dynamics
HAWC2
DTU Wind Energy, Technical University of Denmark
Design Approach
DeepWind floating vertical axis wind turbine concept
Rotor & tower
Floating support
structure & mooring system
Generator & electrical system
Turbine controller
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DTU Wind Energy, Technical University of Denmark
Integrated Simulation Challenges Overview
Simultaneous development of design & design tool
↓ New tool capabilities, design changes, improved reference data
↓ Challenging design environment
↓ Issues with integrated simulation instabilities
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DTU Wind Energy, Technical University of Denmark
Integrated Simulation Challenges Stable operation – U=8m/s
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Torq
ue
Gen
erat
or
hous
ing
yaw
DTU Wind Energy, Technical University of Denmark
Integrated Simulation Challenges Stable operation – U=8m/s
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Flap
wis
e de
fln.
Edge
wis
e de
fln.
Blade mid-point
DTU Wind Energy, Technical University of Denmark
Integrated Simulation Challenges Blade Instabilities
• Very large 2p load fluctuations. • Stall controlled rotor → low, possibly negative blade edgewise damping
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DTU Wind Energy, Technical University of Denmark
Integrated Simulation Challenges Blade Instabilities
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DTU Wind Energy, Technical University of Denmark
Integrated Simulation Challenges Controller/Drivetrain Instabilities
• Conventional PI controller with gain scheduler • Simplified aerodynamic load model
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DTU Wind Energy, Technical University of Denmark
Future Design Cycles
Need to increase design iterations within limited timescale
↓ Multi-Discipinary Design, Analysis & Optimization
(MDAO)
↓ Integration of design and simulation tools
e.g. OpenMDAO, FUSED-wind
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DTU Wind Energy, Technical University of Denmark
Single Environment
Future Design Cycles
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Create simplified subsystem models
Integrate simplifiied models into system
model
Use simplified system model in an optimization context
Translate simplified model into a
complex model
Stability anaylsis: Linearize complex
model around operating points
Use complex model for further
optimisation
DTU Wind Energy, Technical University of Denmark
Conclusions • Design tool that integrates all phenomena taking place
• Independent subsystem design approach
• Simulation challenges when integrating subsystems
• Improve future design cycles
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Need for efficient integrated simulation tools and MDAO
DTU Wind Energy, Technical University of Denmark
Acknowledgements
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The work is a result of the contributions within the DeepWind project which is supported by the European Commission, Grant 256769 FP7 Energy 2010- Future emerging technologies, and by the DeepWind beneficiaries:
DTU(DK), AAU(DK), TUDELFT(NL), TUTRENTO(I), DHI(DK), SINTEF(N), MARINTEK(N), MARIN(NL), NREL(USA), STATOIL(N), VESTAS(DK) and NENUPHAR(F).
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 256769
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