Experimental Measurements of WindFloat 1 Prototype Responses and Comparison With Numerical Model

This paper presents experimental results of WindFloat 1 platform and comparisons with the numerical model developed by Principle Power. The WindFloat platform is designed to support multi-megawatt wind turbines. A full-scale prototype was installed offshore Portugal from 2011 to 2016, and produced 17GWh into the Portuguese grid. An extensive monitoring system was installed, including a wave rider buoy, 6-degrees of freedom measurement devices, anemometers, strain gauges, turbine monitoring instruments. Important results obtained during the measurement campaign are described in this paper. These include power predictions, turbine and tower loads, and platform motions. Comparison with numerical simulations are also provided. The numerical analysis methodology includes fully coupled simulations, based on Orcaflex, a commercially available state-of-the-art software to compute the hydrodynamic response of floating systems, combined in the time-domain with FAST, a well-established numerical tool for the design of wind turbines. Results of these comparisons show that the numerical tools are fit for purpose, and were used to calibrate some hydrodynamic coefficients that cannot be obtained accurately with numerical analysis or scaled model tests.