Artificial and Natural Excitation Testing of SWiFT Vestas V27 Wind Turbines

Abstract

The Scaled Wind Farm Technology facility has been developed by Sandia National Laboratories to enable rapid, cost-efficient testing and development of transformative wind energy technology. As part of this effort, ATA Engineering was contracted by Sandia to perform modal testing on multiple fully assembled wind turbines to gain a better understanding of the structures.

This paper presents the results obtained from experimental modal analysis and operational modal analysis performed on Vestas V27 wind turbines recently installed at the Scaled Wind Farm Technology facility. Experimental modal results are compared between two identical wind turbines, identifying variability in both components and boundary conditions. Additionally, operational modal analysis was used on a single parked wind turbine under natural wind excitation. The operational modal results compare well to the results obtained from a conventional impact modal survey, providing promising results for future testing on larger turbines where measured external excitation may not be feasible.

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy under Contract DE-AC04-94AL85000.