Assessing code-based design wind loads for offshore wind turbines in China against typhoons

Abstract

In the areas prone to severe typhoons, such as the south and southeast China waters, offshore wind turbine design will most likely fall into Class-S, but the current design standards have not treated much detail on the technical parameters under the typhoon-induced conditions to guide the structural design. This study set out to investigate the feasibility of extreme wind conditions in existing standards for offshore wind turbines in the south and southeast China waters. The extreme wind conditions in existing standards and actual typhoon cases in the south and southeast China waters were used to compare and analyze the typhoon-induced wind effect on offshore wind turbines. This study supports evidence from previous views that the extreme wind condition specified by existing design standards does not provide a sufficient safety margin for the south and southeast China waters use. Another interesting finding is that from the perspective of the typhoon-resistant design of large-scale offshore wind turbines in the future, it is more inclined to abandon the height of the hub and use the height of 10m as the reference wind speed height to obtain a more reasonable wind speed field as input conditions. The insights gained from this study may be of assistance to the typhoon-resistant design of customized offshore wind turbines in the south and southeast China waters and would help reduce the risks and economic losses of Class-S wind turbines in other typhoon-prone areas.