Spatiotemporal typhoon impacts on wind speed field of offshore wind farms in the worst scenario of Chinese waters

The comprehensive examination of typhoon impacts on offshore wind power in Chinese waters, which are prone to severe typhoons, remains largely unexplored. This paper takes a step toward assessing extreme design wind conditions for offshore wind turbines in Chinese waters and investigates typhoon-induced wind conditions considering their spatiotemporal effects. For this purpose, a spatiotemporal analysis framework for typhoons was proposed that includes a data-driven typhoon wind speed field model and estimation method of the extreme wind speed. The wind speed field model introduces a measured correction coefficient to enhance the generalization across various observed typhoons, thereby accurately capturing spatiotemporal typhoon effects. The analysis framework was applied to dozens of typical worst-case scenarios of typhoons passing through offshore wind farms in Chinese waters. These scenarios were selected based on typhoon observation data from the past 30 years. The quantitative analysis assesses and discusses the spatiotemporal impacts of typhoons on the mean wind speed, fluctuating wind speed, extreme wind speed, peak factor, and gust factor. The results indicate significant spatiotemporal impacts of typhoons on the inflow wind speed field. The maximum gust wind speed difference could exceed tenfold at various times or for different turbines. This study offers an interpretation of why wind turbines within the same wind farm may experience varying degrees of damage during identical typhoon attacks. By examining the spatiotemporal variation characteristics of typhoons and the corresponding induced wind speed fields, this paper highlights the significance of these factors for typhoon-resistant design in offshore wind farms, thus aiding in ensuring the structural safety of offshore wind turbines.