Integrated design of a semi-submersible floating vertical axis wind turbine (VAWT) with active blade pitch control

Fons Huijs,Koert Lindenburg,Feike Savenije,Ebert Vlasveld,Sébastien Gueydon,Carlos Simao Ferreira,Bruce Leblanc,Benoît Paillard,William Otto,Maël Gormand,Marco Caboni

doi:10.1088/1742-6596/1104/1/012022

Abstract

A semi-submersible Tri-Floater has been designed to support a 6 MW vertical axis wind turbine (VAWT) with active blade pitch control. Due to the low centre of gravity and large allowable floater tilt angle, a relatively small floater can be used to support a VAWT. Coupled simulations including hydrodynamics, mooring system, aerodynamics and control system have been performed to analyse the strongly coupled dynamics of floater and wind turbine. Software tools have been developed or upgraded to enable these simulations. Based on typical extreme operational and survival design load cases, it is illustrated that the active blade pitch control system can be successfully used to minimize the governing loads on the floater. Whereas for a VAWT with fixed blades, the parked survival conditions are typically design driving for the floating support structure, this is not the case if blade pitch control is applied. It is concluded that, compared to a horizontal axis wind turbine (HAWT) with the same rated power, a 20 percent lighter floater can be used as support structure for the VAWT with active blade pitch control.

Highlights

With the offshore wind industry moving towards larger turbines and deeper waters, the potential for floating vertical axis wind turbines (VAWT) is increasing
It is concluded that, compared to a horizontal axis wind turbine (HAWT) with the same rated power, a 20 percent lighter floater can be used as support structure for the VAWT with active blade pitch control
Governing load cases As highlighted by Galinos et al [10], the design of floating vertical axis wind turbines with fixed blades would typically be governed by high wind loads during parked survival conditions

Summary

Introduction

With the offshore wind industry moving towards larger turbines and deeper waters, the potential for floating vertical axis wind turbines (VAWT) is increasing. The VAWT can probably be scaled to larger turbine sizes more than the horizontal axis wind turbine (HAWT) [1]. The VAWT is very well suited for application on a floating support structure. Compared to a HAWT, the generator and the overall centre of gravity of a VAWT is located lower. A VAWT allows for larger floater tilt angles than a HAWT. A smaller and more cost-effective floater can be used to support a VAWT

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