Analysis and simulation study on typhoon wind speed characteristics based on offshore wind turbine structure

Typhoons feature high wind speeds, rapid wind direction changes, and intense turbulence, which bring severe threats to the safe operation of offshore wind turbines. Based on field measurements obtained using a three-dimensional ultrasonic anemometer at an offshore wind farm in Zhejiang Province, China, this paper systematically analyzes the mean and fluctuating wind characteristics under typhoon conditions. Two typical time-varying evolution patterns of mean wind speed are summarized, and the variation rules of wind direction angle are investigated. The results show that the longitudinal turbulence intensity ranges from 0.2 to 0.4 at the height of 35 m. The probability distribution of fluctuating wind speed approximates a Gaussian distribution, and the frequency-domain energy distribution generally follows the von Karman turbulence spectrum. In accordance with the measured typhoon wind statistical properties, the harmonic superposition method is adopted to generate typhoon wind field time histories. On this basis, the typhoon wind speed simulation software is compiled and its reliability and accuracy are validated against measured data. The findings of this study can provide technical support for wind field reconstruction and structural safety evaluation of offshore wind turbines subjected to typhoon loads.