Offset-Free Stochastic MPC for Uncertain Wind Energy Conversion System

The stochastic uncertainty of wind speed presents a significant challenge for ensuring reliable power control in wind energy conversion system (WECS). Stochastic model predictive control (SMPC) emerges as a promising strategy for WECS, leveraging its capacity to effectively handle wind uncertainties through probabilistic descriptions. However, the nonlinear dynamics of wind turbine systems impede the advancement of SMPC in WECS. To address this issue, an offset-free SMPC approach for WECS is proposed, aiming to achieve offset-free rated power tracking, while ensuring the security of WECS during operation in the full load region. A Luenberger observer is employed to estimate the model-plant mismatch introduced by the linearization process, while a tube-based SMPC is deployed to handle stochastic wind speed disturbances for fulfilling probabilistic constraints. Simulation results, including experiments conducted on fatigue, aerodynamics, structures, and turbulence (FAST), are presented to validate the effectiveness of the proposed strategy under different scenarios.