In this paper, we present a methodology for proceeding from the short-term observations of extreme loads to the long-run load distribution of these extreme events, for both flap and edge loading in both operating and parked wind turbine conditions. First, a general approach utilizing full integration, where numerical routines are used to directly integrate the conditional short-term load distribution over the annual occurrence of wind speeds and turbulence intensities, is presented. Then starting from this general approach, a qualitative analysis is undertaken to explore the extent of the contribution of each of the three variables in the governing equation to the variability in the long-term extreme load distribution. From this analysis, lower-order models are considered, where instead of using the entire distribution of the variables, a constant fractile of the short-term extreme load distribution, turbulence intensity distribution, or both are used. Finally recommendations are given to guide the analyst to decide when simpler, yet robust, methods which account for sufficient variability in extreme load events may be employed with confidence.

Issue Section:
Technical Papers
Keywords:
wind turbines, turbulence
Topics:
Stress, Turbulence, Wind velocity, Probability, Wind turbines, Turbines
1.
American Institute of Steel 'Construction Inc., 1986, Manual of Steel Design, Load and Resistance Factor Design, First Edition, Chap. 6, American Institute of Steel Construction, Inc., pp. 142–146.
2.
IEC/TC8, 1998, 61400-1 Wind Turbine Generator Systems - Part 1: Safety Requirements, International Electrotechnical Commission, Geneva, Switzerland.
3.
McCoy, T. J., Malcom, D. J., and Griffin, D. A., 1999, “An Approach to the Development of Turbine Loads in Accordance with IEC 1400-1 and ISO 2394,” Proc. of 1999 ASME Wind Energy Symp. at 37th AIAA Areospace Sciences Meeting, AIAA-99-0020, Reno, NV, pp. 1–9.
4.
Winterstein, S. R., and Kashef, T., 1999, “Moment-Based Load and Response Models With Wind Engineering Applications.” Proc. of 1999 ASME Wind Energy Symp., at 37th AIAA Aerospace Sciences Meeting. AIAA-99-0068, Reno, NV, pp. 122–128.
5.
Manuel, L., Veers, P. S., and Winterstein, S. R., 2001, “Parametric Models for Estimating Wind Turbine Fatigue Loads for Design,” Proc. of 2001 ASME Wind Energy Symp., at 39th AIAA Areospace Sciences Meeting, AIAA-2001-0047, Reno, NV, pp. 276–287.
6.
Fitzwater, L. M., and Winterstein, S. R., 2001, “Predicting Design Wind Turbine Loads from Limited Data: Comparing Random Process and Random Peak Models,” Proc. of 2001 ASME Wind Energy Symp., at 39th AIAA Areospace Sciences Meeting, AIAA-2001-0046, Reno, NV, pp. 355–364.
7.
Ronold
,
K. O.
, and
Larsen
,
G. C.
,
1999
, “
Reliability-Based Design of Wind-Turbine Rotor Blades Against Failure in Ultimate Loading
,”
Eng. Struct.
,
22
, pp.
565
–
574
.
8.
Atlantic Orient Corporation, www.aocwind.net, 2000, AOC 15/50 Specification.
9.
Manuel, L., Kashef, T., and Winterstein, S. R., 1999, “Moment-Based Probability Modelling and Extreme Response Estimation: The FITS Routine, Version 1.2,” Tech. Report RMS–38, Reliability of Marine Structures Program, Civil and Environmental Engineering Dept., Stanford Univ., Stanford, CA.
10.
Rice, J. A., 1995, Mathematical Statistics and Data Analysis, Second Edition, Duxbury Press, Belmont, CA.
11.
Veers, P. S., and Winterstein, S. R., 1997, “Application of Measured Loads to Wind Turbine Fatigue and Reliability Analysis,” Proc. ASME Wind Energy Symp., pp. 160–169.
12.
Haver, S., Sagli, G., and Gran, T., 1998, “Long Term Response Analysis of Fixed and Floating Structures,” Proc. of Wave’98–Ocean Wave Kinematics, Dynamics and Loads on Structures, Int. OTRC Symp., pp. 240–248.
13.
Winterstein, S. R., and Engebretsen, K., 1998, “Reliability-Based Prediction of Design Loads and Responses for Floating Ocean Structures,” Proc. of 17th Int. Offshore Mech. Artic Eng. Symp., ASME, Paper No. OMAE 98-1381.
14.
Engebretsen, K., and Winterstein, S. R., 1998, “Probabilistic Specification of Metocean Criteria: Generating and Searching N-Year Contours for Extreme Response Estimation,” Tech. Rep. RMS–32, Reliability of Marine Structures Program, Civil and Environmental Engineering Dept. Stanford Univ., Stanford, CA.
Copyright © 2002
 by ASME
You do not currently have access to this content.