Multi-objective wake steering optimization for monopile offshore wind turbines considering pile-soil interaction

Wake effects reduce downstream wind turbine power output, significantly impacting offshore wind farm performance. While wake steering strategies can mitigate these adverse effects, they also influence the dynamic response and fatigue damage of both upstream and downstream turbines. However, existing studies have overlooked the critical role of pile-soil interaction (PSI) in this context. This study investigates a 3×3 offshore wind farm with monopile foundations, examining how wake steering affects turbine dynamic response and fatigue damage when PSI is considered. Using coupled FAST.Farm (version 3.4.1) and Abaqus (version 2020) simulations, we conduct multi-objective optimization targeting both total power output enhancement and tower base fatigue damage mitigation. Results reveal that PSI significantly amplifies turbine dynamic response and fatigue damage under wake steering conditions. As yaw angle increases, upstream turbine fatigue damage decreases by up to 76.5%, while downstream turbines show variable responses. Both lower inflow speeds and reduced turbulence intensity facilitate power output enhancement, with total power increasing by 12.2% (at 10% turbulence intensity) and 7.5% (at 7 m/s inflow speed) compared to baseline cases. Maximum tower base fatigue damage decreases across all scenarios, with peak reduction of 65.4% occurring at 11.4 m/s. These findings highlight the importance of considering PSI in wake steering optimization and provide practical guidelines for offshore wind farm control strategies.