On-Condition Evaluation of How Inertial and Aerodynamic Characteristics Affect the Dynamics of a Small Wind Turbine System

Abstract

With the goal of developing system performance integrity monitoring tools for wind turbines the dynamic analysis of a small horizontal-axis wind turbine subjected to changes in the inertial and aerodynamic properties are investigated. The identification of the threeblade turbine modal properties, i.e. natural frequencies, damping ratios, and mode shapes, is provided for a rotor subjected to simulated operating conditions during wind tunnel tests. Several wind speeds and different angular speeds are considered by controlling the inflow to the rotor and its generated power. An identification procedure to infer about how dynamic properties are changing from the data recorded during the simulated operating conditions is developed. The operational deflection shape identification procedure proposed accounts for the presence of harmonic loading and uses dynamic strain measured from Fiber Bragg Grating (FBG) transducers bonded on the surface, suction side, of the three-blades wind turbine.