Torsional vibration suppression of the PMSG-based wind turbine generator using H∞ observer

This paper presents a method for torsional vibration suppression of the PMSG-based wind turbine using H_∞ observer. Due to the wind speed variation, continuous torsional torque fluctuation occurs from the drive shaft of the windmill. Twisting occurs between the wind turbine and generator due to the difference of the inertia of the windmill and the generator. As a result, the shaft may damage due to the metal fatigue of the shaft. Furthermore, measurement of the torsional torque is difficult in the actual machine. Therefore, a method for estimating the torsional torque is required. The proposed method estimates the torsional torque and suppress the torsional torque of the shaft by using the H_∞ controller.