Wind Energy Science 

This work evaluates which wind-inflow- and wake-related parameters have the greatest influence on fatigue and ultimate loads for turbines in a small wind farm. Twenty-eight parameters were screened using an elementary effects approach to identify the parameters that lead to the largest variation in these loads of each turbine. The findings show the increased importance of non-streamwise wind components and wake parameters in fatigue and ultimate load sensitivity of downstream turbines.

The seismic soil-structure interaction of wind turbine support structures is investigated. Wind turbine support structures are modeled by the sway-rocking model and its seismic loadings are analytically derived by complex response spectrum method. To improve the prediction accuracy of the shcar force on footings, an upper limit of modal damping ratios is proposed. The proposed method is demonstrated to be capable to accurately and efficiently estimate the seismic loadings on towers and footings.

In this work, an adaptive control strategy for controlling the lifetime of wind turbine components is proposed. Performance of the lifetime controller is adapted based on real-time health status of the rotor blades to guaranty a predefined lifetime. It shows promising results in lifetime control of blades without speed regulation and tower load mitigation trade-off. It can be applied in optimizing maintenance scheduling of wind farms, which increases reliability and reduces maintenance costs.