Wind conditions for wind turbine design proposals for revision of the IEC 1400-1 standard

The International Electrotechnical Commission (IEC) TC88 formed a subcommittee to re-evaluate the external wind condition models defined in the standard for “Wind Turbine Generator Systems, Part I: Safety Requirements” 1400-1. These models define design turbulence conditions, extreme gust transients, extreme wind direction transients and extreme shear transients as well as other normal and extreme conditions. The TC88 subcommittee solicited extreme wind condition data from countries throughout the world reporting such parameters as maximum gust magnitudes, minimum gust rise times, and extreme wind shears. These data were used to modify the IEC models to be more representative of typical field conditions. Some data used for comparison together with the new models are presented.