Identification of the dynamics of large wind turbines by using photogrammetry

Abstract

In this work, the initial results of the infield tests performed to investigate the feasibility of using photogrammetry in monitoring the dynamics of large scale wind turbines in operation are presented. Within the scope of the work, the response of a wind turbine, with a rotor diameter of eighty meters, was captured by using four CCD cameras simultaneously while the turbine was in operation. The captured response was then analyzed by using two different system identification techniques based on Least Square Complex Exponential (LSCE) method and Sub-space System Identification (SSI) while the dynamic characteristics (the frequencies, damping ratios and mode shapes) of the turbine were derived. Possible effects of very high modal damping ratios and relatively short measurement periods on the identified results were also considered. ©2010 Society for Experimental Mechanics Inc.