J0503-1-2 Turbulent Characteristics in Domestic Sites in Relation to IEC-61400 NTM model

Abstract

Wind data at 290 points widely distributed in domestic potential wind farm sites were assessed in view of turbulence with regards to Turbulence model (NTM) in IEC91400-1Ed.3. While observed mean 15m/s turbulence intensity exceeded NTM cat.A value(=0.16) only at 20% of the investigated sites, observed 90% quantile exceeded NTM cat.A representative value at 48% of the sites. This discrepancy in the NTM coverage between mean and 90% quantile mainly comes from the fact that estimation of variance of σ in NTM is far below observation. Some idea of modification to NTM model to adequately describe the observation is presented.