Wind Turbine Control for Spatially Varying Turbulence

ABSTRACT This study investigates the influence of inflow turbulence generation simulation methods and blade pitch control strategies on the performance and blade structure loading of a large offshore wind turbine. Two inflow representations were considered: synthetic Kaimal turbulence generated in accordance with IEC design standards and large‐eddy simulation (LES) of a neutral atmospheric boundary layer with a mean hub height turbulence intensity of approximately 6%. Both inflows were applied using Taylor's frozen turbulence hypothesis and included steady induction from precursor blade element momentum theory (BEMT) simulations for turbine–flow interaction, enabling a direct comparison of inflow and control effects. The turbine is also represented in the model using a quasi‐steady BEMT code, Maya, which provides aerodynamic forces on to the device. Control strategies evaluated included collective pitch control (CPC) and individual pitch control (IPC) implemented within a proportional‐integral (PI) controller. Results show negligible differences in mean power output between CPC and IPC, indicating that IPC can be employed as a blade fatigue mitigation measure without compromising energy capture. Across both inflow types, IPC reduced the fatigue loads due to the blade root bending moment (RBM) by 11%–15%, with a greater reduction for the Kaimal turbulence. Compared to Kaimal, LES inflow produced lower overall RBM fatigue loads at the same onset wind speeds, despite exhibiting greater average blade‐to‐blade variation due to spatially varying turbulence structures. These spatial asymmetries, which were not fully mitigated by the fixed‐gain IPC, are of particular concern for floating platforms, as they can lead to unbalanced rotor thrust and potential excitation of platform surge and pitch modes. The findings indicate that IEC‐based synthetic turbulence may overpredict fatigue loads relative to more realistic offshore inflow conditions captured by LES, but that spatial variability in such inflows can challenge current control approaches.