Non-Gaussian Extension of Current Wind Field Models in IEC 61400-1 and their Impact on Wind Turbine Loading

We present a non-Gaussian extension of current wind field models in IEC 61400-1 that considers the empirically observed presence of strong, anomalous wind field fluctuations in atmospheric turbulence. Our method is based on so-called superstatistics [J. Friedrich et al. PRX Energy 1 (2), 023006 (2022)], which represents a Gaussian mixture of Kaimal- or Mann-type wind fields with locally fluctuating covariances. An additional parameter, the intermittency parameter μ, determines the heavy-tail behavior of the probabilities of fluctuations of those superstatistical Mann or Kaimal wind fields and can be estimated site-dependently from atmospheric turbulence measurements. Using aeroelastic simulations, we explicitly demonstrate that non-Gaussian properties have a non-negligible influence on both extreme and fatigue loads of different wind turbines. Furthermore, we discuss the implications of our findings for the future design of wind turbines with increasing rotor diameter.