An estimation of the extreme wind speed using the Korea wind map

In this study, extreme wind speeds were estimated from the Korea wind map in order to ensure the structural safety of wind turbines. Fifteen major wind farm sites in Korea were selected as target locations for the study. The daily and monthly maximum wind speeds for a three-year span (2005–2007) were extracted from the time-series wind speed of the numerical analysis data obtained at a height of 80 m above ground, and were converted into average times of 3 s and 600 s. The Gumbel and Weibull distributions were used as the probability distribution models for the extreme values, from which the extreme wind speeds were estimated. In order to ascertain the accuracy of the extreme values estimated from the numerical analysis data, they were compared with the extreme values obtained from actual field measurement data collected at a height of 30 m above ground. The results of the comparison indicated that the extreme values for both the numerical analysis data and the field measurement data were identical. The results also showed that the Gumbel distribution model predicts the extreme wind speeds more accurately than the Weibull distribution model does. Therefore, it was decided that the monthly maximum wind speed would be selected to estimate extreme wind speeds for extreme values. Extreme values estimated from the field measurement data at 30 m high above ground. After the comparison, it was found that there was an agreement in the extreme values from both the numerical analysis data and the field measurement data. So, it was more reliable to use the Gumbel distribution as the model of extreme wind speeds than the Weibull distribution, and therefore, it was decided to select the monthly maximum wind speed in order to estimate the extreme wind speeds for extreme values.