Abstract
In the near future, the offshore wind industry will experience a significant increase of turbine size and of floating wind development activities. A floating offshore wind turbine foundation offers many advantages, such as flexibility in site selection, access to better offshore wind resources, and quayside integration to avoid a costly heavy lift vessel offshore campaign. PyraWind™ is a patented three canted column semisubmersible floating foundation for ultra large offshore wind turbines. It is designed to accommodate a wind turbine, 14 MW or larger, in the center of the interconnected columns of the hull with minimal modifications to the tower, nacelle and turbine. The pyramid-shaped hull provides a stable, solid foundation for the large wind turbine under development. This paper summarizes the feasibility study conducted for the PyraWind™ concept. The design basis for wind turbine floating foundations is described and the regulatory requirements are discussed. Also included are the hydrodynamic analysis of the hull and ongoing work consisting of coupling hull hydrodynamics with wind-turbine aerodynamic loads. The fully coupled system was analyzed using OpenFAST, an aerodynamic software package for wind turbine analysis with the ability to be coupled with the hydrodynamic model. Due to the canted columns, a nonlinear analysis was performed using the coupled numerical hydrodynamic model of the platform with mooring system in extreme sea states.
Backstepping Control of Heavy Lift Operations with Crane Vessels
