Experimental and analytical performance assessment of a wind turbine

Abstract

In this study, the performance assessment of the wind turbine in the Sar tepe Campus of the Boğaziçi University under wind and seismic loadings is performed. For this purpose, the nite element model of the wind turbine is developed in SAP2000 software. In the model, the foundation is also included to consider the soil exibility on dynamic properties. The soil around piles is modeled with soil springs and the sti nesses of these springs are determined according to the API guideline. Then, FEM updating is performed with two parameters which are steel Young's modulus and soil spring coe cient percentage. In the development of the error function used in the FEM updating process, natural frequencies and mode shapes of the rst three modes are used. Then, a nonlinear model of the wind turbine considering the soil exibility is developed in ANSYS software and pushover analysis is performed. The in uence of considering dead load and initial imperfection is also investigated in the pushover analysis. Then, demand and capacity curves are compared, and performance point is obtained. Seismic fragility analysis considering wind load action of various mean wind speeds is performed with 11 earthquake records selected according to the design spectrum. Then, the resonance phenomenon is investigated to see whether the wind turbine experiences an additional excitation because of resonance but results show that additional excitation is not seen due to resonance e ect. Finally, the theoretical buckling capacity of the wind turbine is calculated according to two di erent references and it is seen that analytical calculations give reasonable buckling capacities.