Fatigue Reliability of Wind Turbine Fleets: The Effect of Uncertainty on Projected Costs

Abstract

Fax (505)845-9500 ABSTRACTThe cost of repairing or replacing failed components depends on the number and timing of failures.Although the total probability of individual component failure is sometimes interpreted as the percentage of components likely to fail, this perception is often far from correct. Different amounts of common versus independent uncertainty can cause different numbers of components to be at risk of fkilure. The FAROW tool for fatigue and reli,ability analysis of wind turbines makes it possible for the first'time to conduct a detailed economic analysis of the effects of uncertainty on fleet costs. By dividing the uncertainty into common and independent parts, the percentage of components expected to fail in each year of operation is down enables the calculation of costs associated with various probability of occurrence levels, illustrating the variability in projected costs. Estimating how the numbers of components expected to fail evolves over time is also useful in calculating the present value of projected costs and in understanding the nature of the financial risk.

On the Fatigue Analysis of Wind Turbines

“…Veers [188] details the techniques used in a typical evaluation. Once know the failure probability can be incorporated into a financial analysis program to determine the financial risk for investors.…”

Reliability-based gear contact fatigue analysis for wind turbines under stochastic dynamic conditions

“…The main benefit of this method is that uncertainty of design parameters could be considered explicitly and hence the effect of uncertainty on project costs could be estimated (Veers 1995).…”

Gear Contact Fatigue Reliability Analysis for Wind Turbines Under Stochastic Dynamic Conditions Considering Inspection and Repair

“…The main benefit of this method is that uncertainty of design parameters could be considered explicitly and hence the effect of uncertainty on project costs could be estimated [13]. In addition, it is also useful for rational and optimal planning of operation (services, inspections, etc.)…”

“…Recently Dong et al [25] performed a comprehensive study on the fatigue reliability of the jacket support structure for offshore wind turbines based on time domain simulation, where the major uncertainties in the whole analysis procedure are identified and analyzed. Base on the work of Veers [13], material fatigue properties can be used to approximate all the independent uncertainty from component to component. In practice, identical material specimens tested at the same stress level can have lifetimes that differ by a factor of ten or more [13].…”

“…Base on the work of Veers [13], material fatigue properties can be used to approximate all the independent uncertainty from component to component. In practice, identical material specimens tested at the same stress level can have lifetimes that differ by a factor of ten or more [13]. A typical value for the standard deviation of the cyclesto-failure could be taken as 60% of the mean value [26].…”