Real-time hybrid aeroelastic simulation of wind turbines with various types of full-scale tuned liquid dampers

The present paper presents the real-time hybrid simulation (RTHS) technique for multimegawatt wind turbine (WT) with various types of full-scale tuned liquid dampers (TLDs). As an evolvement of the pseudodynamic testing technique, the RTHS is executed in real time, thus allowing accurate investigation of the interaction between the aeroelastic WT system and the rate-dependent nonlinear TLD device. As the numerical substructure, the WT is simulated in the computer using a 13-degree-of-freedom (13-DOF) aeroelastic model. As the physical substructure, the full-scale TLDs are manufactured and physically tested. They are synchronized with each other by real-time controllers. Taking advantage of RTHS technique, 2- and 3-MW WTs have both been simulated under various turbulent wind conditions. TLDs with different configurations have been extensively investigated, eg, various tuning ratios by varying the water level, TLD without and with damping screens (various mesh sizes of the screen considered), and TLD with flat and sloped bottoms. It is shown that a well-designed TLD is very effective in damping lateral tower vibrations of WTs. Furthermore, RTHS results and results from a proposed theoretical model are compared. This study gives comprehensive guidelines for employing various types of TLDs in large WTs and indicates huge potentials of applying RTHS technique in the area of wind energy.