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

This article focuses on assessing the spatiotemporal impacts of typhoons on the inflow wind speed fields of large offshore wind turbines (LOWTs) in Chinese waters, a region frequently affected by severe typhoons. Using a data-driven typhoon wind speed field model and extreme value estimation methods, the study analyzes worst-case scenarios based on the five most powerful typhoons over the past 30 years, with Typhoon Rammasun as the primary case. Results reveal significant spatial and temporal variability in wind speeds within the same offshore wind farm (OWF), with differences in mean and extreme wind speeds exceeding design standards by large margins, explaining why turbines in the same farm may experience varying damage levels during identical typhoon events. The study also finds that commonly used peak and gust factor values in design codes underestimate the pulsation intensity of typhoon-induced winds, proposing a logarithmic height-dependent gust factor profile to improve design accuracy. These findings underscore the necessity of incorporating spatiotemporal typhoon variability into the structural design and safety assessment of LOWTs to enhance resilience against extreme typhoon loads.