Active damping of torsional resonance in wind turbine drivetrains

Two mitigation methods for torsional resonance are tested on a 750 kw wind turbine using the NREL software FAST in the MATLAB/Simulink environment. One mitigation method is an active vibration absorber and the other method uses rotor angular acceleration measurements to provide virtual inertia for resonance detuning. The wind turbine representation uses a five mass gearbox model, a PMSG model, and aerodynamic simulation of the tower shadow effect. The two mitigation methods are tested by subjecting them to a frequency scan of wind to demonstrate the resonant condition and its mitigation using the methods. The vibration absorber shows better performance with shaft oscillation reduction than that of the virtual inertia.