Optimal active control strategy for flutter suppression in wind turbine blades based on unsteady aerodynamics

Classical flutter in wind turbine blades threatens structural safety and reduces system reliability, posing a critical challenge in large wind turbine design and operation. This paper addresses the flutter issue by developing a precise aeroelastic model and an efficient active control strategy. Initially, an aeroelastic coupling model was created using Theodorsen's unsteady aerodynamic theory and Lagrangian equations, validated through wind tunnel tests of the NACA_64_618 airfoil. Building on this, a novel aeroelastic model with discontinuous control surfaces for wind turbine blades was proposed. An optimal active control law, using an electric motor as the actuator, was derived to enhance control practicality. Numerical simulations on a typical wind turbine blade section were performed using Simulink to analyze the impact of the control strategy on aeroelastic responses. Comparative studies showed that this method effectively mitigates blade flutter by adjusting the aerodynamic force distribution. The results validate the model and control framework, providing a new theoretical approach for aeroelastic analysis and active control of large wind turbine blades.