Abstract
This paper proposes a pitch control strategy to mitigate the underwater acoustic footprint of offshore wind turbines, a measure that might soon become necessary to minimize impacts on marine life, which rely on sound for communication, navigation, and survival.
Building upon a previously proposed open-loop individual pitch control approach [1], we extend the methodology to account for varying inflow conditions and wind farm interactions. The IPC strategy modulates blade pitch at the blade-passing frequency to reduce overall sound pressure level and amplitude modulation, while being coupled with a standard collective pitch controller to ensure adaptability under under-rated and over-rated operating regimes. The approach is evaluated for three representative turbine models (NREL 5 MW, DTU 10 MW, and IEA 22 MW) and subsequently applied to a small wind farm configuration. Results demonstrate consistent underwater noise reduction across operating conditions, with lower impact on power production than standard noise reduction operation methods. At the wind farm scale, the proposed control strategy achieves a measurable reduction in underwater noise while maintaining nearly unchanged total power output. These findings indicate that individual pitch control offers a promising pathway toward quieter offshore wind farms without compromising energy generation.