Hybrid Model Testing of Floating Wind Turbines: Test Bench for System Identification and Performance Assessment

Abstract

The present study shows preliminary results of the SOFTWIND project that aims at developing an innovative experimental test bench dedicated to floating wind turbine wave tank testing. The following methodology is based on a “software in the loop” approach that combines numerical modeling with physical modeling. The originality of the experimental approach lies in the use of an innovative set of actuators located at the top of the wind turbine tower which is in charge of emulating the response of the rotor. First, results of a sensitivity analysis on the specifications of the aerodynamic forces to be emulated are presented. Low pass filtering effect in the actuation — linked to the physical characteristics of the actuators and numerical-physical loop — are first considered through fully coupled numerical simulations for different load cases including turbulent winds, misaligned wind-wave conditions and different floaters. Then, a test bench with imposed motions has been designed for the verification of communication protocols, real-time execution for the numerical model, motion and force observers and preliminary actuator model identification. Response to rising steps combined with white noise identification of the actuator with this test bench give promising results in open loop.