Session: 09-01-01 Wind Turbine Aerodynamics and Control

Submission Number: 157429

Experimental Emulation of Shutdown and Start-Up Procedures in Wave Basin Tests of a 15MW Floating Offshore Wind Turbine 

In the current scenario of increasing demand for renewable energy sources and decarbonization of economic activities, floating offshore wind turbines (FOWT) are deemed a key technology to support energy transition. As with many new emerging technologies developed for offshore environment, research in this field usually relies on experiments performed with scaled models in wave basins. In the case of FOWTs, these tests focus on wave interactions, but also require the proper emulation of wind forces and the effects of the turbine’s control system. An efficient means to emulate the effect of wind on the floating structure requires the aerodynamic loads to be computed by a numerical model concomitantly to the wave experiment. The estimated wind forces are then applied to the model by means of an electromechanical device composed of several drone propellers, configuring an experimental approach known as Software-in-the-Loop (SiL). Such approach not only allows the emulation of aerodynamics loads with constant or turbulent winds, but also to mimic transient stages of system start-up and shutdown. The present work assesses a set of experimental results obtained for a 1:45 model scale of a semisubmersible platform supporting the IEA-15MW reference wind turbine, with emphasis on the dynamics during the turbine’s start-up and shutdown transient stages. A start-up control strategy was implemented in the SIL algorithm and tested in different environmental scenarios of waves and winds. Likewise, a shutdown control was also implemented and tested both with manual commands from a fictitious operator and automatically, in the latter case adopting a wind speed limit as a trigger for the shutdown procedure. The motions of the FOWT during these transient stages were recorded and compared to those predicted from numerical simulations using OpenFAST. It is shown that a fair agreement is obtained, despite minor differences in control strategies between the SiL algorithm and ROSCO turbine controller. No critical dynamic effects were observed during the transients, at least for the environmental conditions that were tested.

Presenting Author: Pedro C. de Mello Universidade de São Paulo - Escola Politécnica - Dpto de Eng Naval.

Presenting Author Biography: Pedro C. de Mello was born in São Paulo,Brazil, in 1976. He received the B.S. degree in electrical engineering from São Paulo State University (UNESP), Ilha Solteira, in 2002, the M.S. degree in oceanic engineering from the Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, in 2006, and the Ph.D. degree in mechatronic engineering from the University of São Paulo (USP), São Paulo, in 2012. From 2004 to2005, he was a Research in LabOceano ocean basin with UFRJ. Since 2006 until today, he was a Research in Numerical Offshore Tank with the University of São Paulo. Since 2012, he has been the wave basin coordinator of Numerical Offshore Tank with the University of São Paulo. From 2017 to 2018, he was an Assistant Professor with the Naval and Oceanic Engineering Department, University of São Paulo.