NEESR-II: A Seismic Study of Wind Turbines for Renewable Energy
Ian Prowell
Presenter, Graduate Student Researcher
PI: Prof. Ahmed Elgamal Co-PI: Prof. Joel Conte
Prof. J. Enrique Luco
Prof. Chia-Ming Uang
Background and Motivation
Source: Sandia National Laboratories
Background
65 kW Nordtank (15 m rotor diameter), 900 kW NEG Micon 52m (52 m rotor diameter), and 3 MW Vestas V90 (90 m rotor diameter)
Background
Enercon 4.5MW 112 Meter RotorSource: Sandia National Laboratories
Construction of Modern Turbine BladeSource: LM Glassfiber
Motivations for Research• Coincidence of wind
resource and seismic hazard– Pacific Rim: US West
Coast, Japan, China, etc
– Mediterranean: Greece, Turkey, etc
• Require combined wind, operational, and seismic load case
Field Vibration Testing: NEES@UCLA
In-Situ Vibration Experiments• 900 kW NEG Micon• 2 hours of data while
operating• 46 hours of parked data• Tower and surrounding soil
instrumented• Forced vibration up to 15 Hz• Data recorded while rotor and
gearbox were removed• Wind speed and operational
data recorded simultaneously with vibration data
In-Situ Vibration Experiments• 1.5 MW NEG Micon• 45 hours of data while
operating• 1 hour of parked data• Tower and surrounding soil
instrumented• Wind speed and operational
data recorded simultaneously with vibration data
In-Situ Vibration Experiments: Outcomes
Side View
Front View
Side View
Front View
Side View
Front View
(a) 1st Side-to-side at 0.54 Hz (b) 1st Fore-aft at 0.56 Hz (c) 2nd Side-to-side at 3.94 Hz
Side View
Front View
Side View
Front View
Side View
Front View
(d) 2nd Fore-aft at 4.00 Hz (e) 3rd Fore-aft at 8.86 Hz (f) 3rd Side-to-side at 10.9 Hz 1
Mode Type Orientation Mean Frequency
Std. Dev. of Frequency
Mean Damping
Std. Dev. of
Damping
1st Bending Side-to-side 0.54 Hz 0.01 Hz 3.4 % 1.2 %
Fore-aft 0.56 Hz 0.01 Hz 4.0 % 1.4 %
2nd Bending Side-to-side 3.94 Hz 0.03 Hz 1.0 % 0.5 %
Fore-aft 4.00 Hz 0.03 Hz 0.9 % 0.4 %
3rd Bending Fore-aft 8.86 Hz 0.10 Hz 1.8 % 0.7 %
Side-to-side 10.9 Hz 0.04 Hz 0.7 % 0.4 %
Shake Table Testing: NEES@UCSD
Shake Table Testing• Dense instrumentation
with in- and out-of-plane components
• Input motions in two perpendicular orientations relative to nacelle
• Input motions in operational and parked conditions
SimulationExperiment
Shake Table Testing: Outcomes• Experimental validation of operational effects
and accurate simulation in using updates to NREL code for turbines
Overall Project Outcomes• Numerous publications sharing results• Provide valuable experimental evidence
supporting seismic behavior of wind turbines• Field work and shake table tests provide
basis for applying results across entire range of existing turbines
• Contributed and validated updates to NREL simulation code for turbines to simulate combined earthquake, operational, and wind loads
• Project personnel provided guidance on seismic loads in development of forthcoming AWEA/ASCE turbine permitting guidelines
Acknowledgements – Organizations • NSF - Grant No. CMMI0830422
• Oak Creek Energy Systems
• NEES@UCLA
• NEES@UCSD
• Sandia National Laboratories
• National Renewable Energy Laboratory
• Harvey Mudd College
Thank You