Test of an active flap system on a 4.3 MW wind turbine

Abstract This article describes a field test performed on 4.3 MW wind turbine with one blade equipped an active flap system. The results presented focus primarily the steady state and periodic characterization of system in different deflection states. tests were between 2020 2021 northern Denmark close-to-shore conditions. is characterized based load response flapwise bending moment blades. Flap actuations are both as open-loop on-off swaps (shifting two positions at fixed time intervals) closed-loop 1P activations (cyclic activation phase counterphase azimuthal position). For swap tests, impact ranges 3% 20% depending actuation level speed. cyclic blade-to-blade fatigue comparison, showing potential reduction approximately 13%.