Extreme wind speed analysis
High wind speeds pose a threat to the integrity of structures, particularly those at exposed sites such as wind turbines. Therefore safety considerations must be balanced against the additional cost of ‘over-design’. Accurate estimation of the occurrence of extreme wind speeds is an important factor in achieving the correct balance.
Both a wind-resistant design and a structural safety assessment require reliable extreme wind speed modeling. The extreme speeds may cover a 50-year or even a 100-year return period. When a certain amount of extreme data is obtained, a statistical cumulative distribution function can be used to describe the distribution status of the extreme values. Extreme wind speed is often used to evaluate offshore wind energy sites and to determine the required structural strength of a wind turbine design.
Our extreme wind evaluation is based on wind measurement data of a measurement station at/close to the site (12 months of data are necessary) and in compliance with IEC61400-12-1 and IEC61400-1 further applicable international standards, the technical guideline TR6 in its latest version and the internal testing method BBB-PrV04. The site evaluation will be executed by application of WAsP Engineering and WindPRO. T The results of the analysis will be in compliance with the “Site Parameter Requirements” of the chosen WTG manufacturer.
To ensure the stability of wind turbines during the average operation time (generally 20 years), a turbulence prognosis is essential. Wind Minds calculates the turbulence intensity in compliance with DIBT and IEC guidelines, based on wind measurements on site (if available), map material, satellite data, site inspections, etc.
The effective turbulence intensity is understood as characteristic parameter of the turbulence load for a given wind farm configuration at the investigated site. It is a very important criterion to be considered in every wind farm planning process. The effective turbulence intensity represents a combination of ambient turbulence and wake turbulence. The ambient turbulence is generated by the site’s general wind conditions and is significantly affected by terrain roughness and terrain profile – obvioulsy to alesser extent on offshore sites. The wake turbulence is produced by the trailing effect of the turbines and is thus determined by the wind farm configuration (number, rotor diameter, distances, etc.).
Our turbulence analysis is based on CFD analysis applying Windsim, on wind measurement data of a measurement station at/close to the site and in compliance with IEC61400-12-1 and IEC61400-1, further applicable international standards, the technical guideline TR6 in its latest version and the internal testing method BBB-PrV03. If necessary the site evaluation will be executed with additional application of WAsP Engineering and WindPRO. The results of the analysis will be in compliance with the “Site Parameter Requirements” of the chosen WTG manufacturer.