Modelling the structural loading of a small wind turbine at a highly turbulent site via modifications to the Kaimal turbulence spectra

This paper compares turbine blade load statistics for inflow turbulence fields based on the open terrain standard Kaimal spectra, as suggested in the standard IEC61400-2 that covers the design and safety standard of small wind turbines, and measured turbulence spectra from a built environment site. The findings show that for extreme, high turbulent intensity winds, the measured spectra predict isolated loading events around twice the magnitude of loads predicted by use of the standard spectra. The work suggests the need for improvements to the standard in order to model the non-Gaussian wind statistics that occur in extreme events such as sudden strong gusts.