Experimental validation of optimal TMD for wind turbines using real-time hybrid simulation

A wind turbine is susceptible to harsh environmental conditions during its design life, which induces excessive vibrational loads on the turbine. These vibrations also affect the quality of the power generation. To address these issues, vibrational response control devices are generally employed. Passive tuned mass dampers (TMD) are commonly utilized for structural control due to their simplicity, inherent stability, and low maintenance. Their operation is independent of any external stimuli. A TMD is only effective if its parameters are tuned appropriately. In this paper, an optimal methodology for designing Tuned Mass Dampers (TMDs) for onshore wind turbines is presented. The design of TMDs is formulated as a control optimization problem, and the methodology can effectively account for model uncertainties. The design methodology is experimentally validated using real-time hybrid simulation (RTHS), where the tower-nacelle assembly is tested physically. The effect of the TMD and the external forces is simulated using a computer model and applied to the physical test specimen using an electromagnetic shaker. The performance of the TMD is assessed for two different external loading scenarios: aerodynamic (wind) loading and earthquake. The experimental results obtained from RTHS demonstrate the effectiveness of the optimal TMD. Also, the RTHS framework presented in this paper provides an economical means for validating optimal TMD for wind turbines.