Statistical analysis of fatigue loads in a direct drive wind turbine

Paper in proceeding, 2014

The design calculation of a wind turbine typically involves a large number of simulations of wind turbine dynamics response. In order to assess the fatigue life of drive train components, we seek to determine how the component damage can be estimated, not only in terms of its expected value, but also its distribution accounting for randomness due to turbulent wind field. It was found that for assessing the fatigue life of main shaft bearings, a quasi-static drive train model may be sufficient for a direct drive concept. Also, it was observed that both the average and variability of the damage rate vary substantially with the mean wind speed. Therefore, in addition to the mean, also the variability of the estimated accumulated component damage should be considered.