Presentation is loading. Please wait.

Presentation is loading. Please wait.

A Quantitative Comparison of Three Floating Wind Turbines

Similar presentations


Presentation on theme: "A Quantitative Comparison of Three Floating Wind Turbines"— Presentation transcript:

1 A Quantitative Comparison of Three Floating Wind Turbines
NOWITECH Deep Sea Offshore Wind Power Seminar January 21-22, 2009 Jason Jonkman, Ph.D. Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute • Battelle

2 Offshore Wind Technology
Onshore Shallow Water 0m-30m Transitional Depth 30m-60m Deepwater 60m+

3 Floating Wind Turbine Pioneers
Developer StatoilHydro, Norway Blue H, Netherlands Principle Power, USA SWAY, Norway Platform “Hywind” spar buoy with catenary moorings Tension-leg concept with gravity anchor “WindFloat” semi-submersible with catenary moorings Spar buoy with single taut tether Wind Turbine Siemens 2.3-MW upwind, 3-bladed Gamma 2-bladed, teetering, yaw-regulated Coordinating with suppliers for 5-MW+ units Swivels downwind Partnering with Multibrid Status $78M demonstration project in North Sea First PoC installed in Summer 2009 Plans to license technology Deployed PoC system with 80-kW turbine in Italy in summer 2007 Receiving funding from ETI for UK-based projects Extensive numerical modeling Tested in wave tank Planning demonstration projects

4 Floating Wind Turbine Concepts
+ relative advantage 0 neutral – relative disvantage TLP Spar Barge Pitch Stability Mooring Ballast Buoyancy Natural Periods + Coupled Motion Wave Sensitivity Turbine Weight Moorings Anchors Construction & Installation O&M Design Challenges Low frequency modes: Influence on aerodynamic damping & stability Large platform motions: Coupling with turbine Complicated shape: Radiation & diffraction Moorings, cables, & anchors Construction, installation & O&M

5 Modeling Requirements
Coupled aero-hydro-servo-elastic interaction Wind-inflow: Discrete events Turbulence Waves: Regular Irregular Aerodynamics: Induction Rotational augmentation Skewed wake Dynamic stall Hydrodynamics: Diffraction Radiation Hydrostatics Structural dynamics: Gravity / inertia Elasticity Foundations / moorings Control system: Yaw, torque, pitch

6 Coupled Aero-Hydro-Servo-Elastics

7 Floating Concept Analysis Process
Use same NREL 5-MW turbine & environmental conditions for all Design floater: Platform Mooring system Modify tower (if needed) Modify baseline controller (if needed) Create FAST / AeroDyn / HydroDyn model Check model by comparing frequency & time domain: RAOs PDFs Run IEC-style load cases: Identify ultimate loads Identify fatigue loads Identify instabilities Compare concepts against each other & to onshore Iterate on design: Limit-state analysis MIMO state-space control Evaluate system economics Identify hybrid features that will potentially provide the best overall characteristics

8 Three Concepts Analyzed
NREL 5-MW on OC3-Hywind Spar NREL 5-MW on ITI Energy Barge NREL 5-MW on MIT/NREL TLP

9 Sample MIT/NREL TLP Response

10 Summary of Selected Design Load Cases from IEC61400-1 & -3
Design Load Case Table Summary of Selected Design Load Cases from IEC & -3

11 Normal Operation: DLC 1.1-1.5 Ultimate Loads Blade Root Bending Moment
Low-Speed Shaft Bending Moment Yaw Bearing Bending Moment Tower Base Bending Moment

12 Floating Platform Analysis Summary
MIT/NREL TLP Behaves essentially like a land-based turbine Only slight increase in ultimate & fatigue loads Expensive anchor system OC3-Hywind Spar Buoy Only slight increase in blade loads Moderate increase in tower loads; needs strengthening Difficult manufacturing & installation at many sites ITI Enery Barge High increase in loads; needs strengthening Likely applicable only at sheltered sites Simple & inexpensive installation

13 Ongoing Work & Future Plans
Assess role of advanced control Resolve system instabilities Optimize system designs Evaluate system economics Analyze other floating concepts: Platform configuration Vary turbine size, weight, & configuration Verify under IEA OC3 Validate simulations with test data Improve simulation capabilities Develop design guidelines / standards Spar Concept by SWAY Semi-Submersible Concept

14 Model Verification through IEA OC3
The IEA “Offshore Code Comparison Collaboration” (OC3) is as an international forum for OWT dynamics model verification OC3 ran from 2005 to 2009: Phase I – Monopile + Rigid Foundation Phase II – Monopile + Flexible Foundation Phase III – Tripod Phase IV – Floating Spar Buoy Follow-on project to be started in April, 2010: Phase V – Jacket Phase VI – Floating semi submersible

15 OC3 Activities & Objectives
Discussing modeling strategies Developing a suite of benchmark models & simulations Running the simulations & processing the results Comparing & discussing the results Assessing the accuracy & reliability of simulations to establish confidence in their predictive capabilities Training new analysts how to run & apply codes correctly Investigating the capabilities / limitations of implemented theories Refining applied analysis methodologies Identifying further R&D needs Activities Objectives

16 Thank You for Your Attention
Jason Jonkman, Ph.D. +1 (303) 384 – 7026 Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute • Battelle

17 Normal Operation: DLC 1.2 Fatigue Loads Side-to-Side Fore-Aft In-Plane
Out-of-Plane Side-to-Side Fore-Aft 90° Blade Root Bending Moments Low-Speed Shaft Bending Moments Yaw Bearing Bending Moments Tower Base Bending Moments

18 DLC 6.2a Side-to-Side Instability
Idling: DLC 6.2a Side-to-Side Instability Aero-elastic interaction causes negative damping in a coupled blade-edge, tower-S-S, & platform-roll & -yaw mode Conditions: 50-yr wind event for TLP, spar, & land-based turbine Idling + loss of grid; all blades = 90º; nacelle yaw error = ±(20º to 40º) Instability diminished in barge by wave radiation Possible solutions: Modify airfoils to reduce energy absorption Allow slip of yaw drive Apply brake to keep rotor away from critical azimuths

19 Idling: DLC 2.1 & 7.1a Yaw Instability
Aero-elastic interaction causes negative damping in a mode that couples rotor azimuth with platform yaw Conditions: Normal or 1-yr wind & wave events Idling + fault; blade pitch = 0º (seized), 90º, 90º Instability in TLP & barge, not in spar or land-based turbine Possible solutions: Reduce fully feathered pitch to allow slow roll while idling Apply brake to stop rotor


Download ppt "A Quantitative Comparison of Three Floating Wind Turbines"

Similar presentations


Ads by Google