Simulating the response of a small horizontal-axis wind turbine during wind gust using FAST

Abstract

Small wind turbines are often erected close to their load and in urban environments where the mean velocity is lower than ideal, and the turbulence level is high. Urban environments experience wind gust events with published results indicating the number of gust events greatly exceeding the number of events assumed in International Electrotechnical Commission (IEC) standard IEC 61400.2-2013. The work presented in this paper has analysed detailed wind measurements from a site in an urban environment to identify wind gust events and has used these wind gust events as an input into a FAST model of a 5 kW horizontal-axis wind turbine. The FAST model predicted the turbine power extracted from the measured gusts are lower than the power extracted during the assumed IEC gust. The maximum energy extracted by the turbine during a gust is at least 36% lower for a measured gust event than for the assumed ideal gust event.