Floating support structure for offshore wind turbine and method for installing a wind turbine provided with such a support structure

A floating support structure for an offshore wind turbine, comprising a float intended to be partly immersed and on which a wind turbine mast is intended to be assembled, and a counterweight connected to the float and intended to be immersed under the float, wherein:

• the float comprises:
• a toroid or polygon-shaped main structure with at least five sides which is formed by at least one tube intended to be immersed;
• a central tubular structure having a diameter adapted to receive the mast of the wind turbine and comprising a section able to be ballasted in order to adjust the waterline of the float;
• a first series of horizontal struts evenly distributed about a vertical axis and connecting the main structure to the central structure;
• and
• a second series of oblique struts evenly distributed about a vertical axis and connecting the main structure to the central structure at an angle comprised between 15° and 60° with the horizontal struts;
• and in that the counterweight comprises a basket able to receive ballast material and ballast links connecting the basket to the main structure of the float at an angle (a) comprised between 15° and 45° with the vertical axis;
• wherein the ballast links form an angle (β) with the vertical axis given by the following equation:
• β=arctan[(Dc/2+Lh+Df)/(P−Te−Ep−Gp)]
• wherein:
• P is the water depth;
• Te is the draft measured at the bottom of the main structure;
• Ep is the thickness of the basket;
• Gp is the distance between the bottom of the basket and the seabed;
• Dc is the diameter of the central structure;
• Lh is the length of the horizontal struts;
• and Df is the diameter of the tubes of the main structure.

A floating support structure for an offshore wind turbine, comprising a float intended to be partly immersed and on which a wind turbine mast is intended to be assembled, and a counterweight connected to the float and intended to be immersed under the float, wherein:

• the float comprises:
• a toroid or polygon-shaped main structure with at least five sides which is formed by at least one tube intended to be immersed;
• a central tubular structure having a diameter adapted to receive the mast of the wind turbine and comprising a section able to be ballasted in order to adjust the waterline of the float;
• a first series of horizontal struts evenly distributed about a vertical axis and connecting the main structure to the central structure;
• and
• a second series of oblique struts evenly distributed about a vertical axis and connecting the main structure to the central structure at an angle comprised between 15° and 60° with the horizontal struts;
• and in that the counterweight comprises a basket able to receive ballast material and ballast links connecting the basket to the main structure of the float at an angle (a) comprised between 15° and 45° with the vertical axis;
• wherein the float further comprises an additional floatability structure formed by an assembly of additional floats mounted on the tube of the main structure.

A floating support structure for an offshore wind turbine, comprising a float intended to be partly immersed and on which a wind turbine mast is intended to be assembled, and a counterweight connected to the float and intended to be immersed under the float, wherein:

• the float comprises:
• a toroid or polygon-shaped main structure with at least five sides which is formed by at least one tube intended to be immersed;
• a central tubular structure having a diameter adapted to receive the mast of the wind turbine and comprising a section able to be ballasted in order to adjust the waterline of the float;
• a first series of horizontal struts evenly distributed about a vertical axis and connecting the main structure to the central structure;
• and
• a second series of oblique struts evenly distributed about a vertical axis and connecting the main structure to the central structure at an angle comprised between 15° and 60° with the horizontal struts;
• and in that the counterweight comprises a basket able to receive ballast material and ballast links connecting the basket to the main structure of the float at an angle (β) comprised between 15° and 45° with the vertical axis;
• wherein the main structure of the float is formed by an assembly of a plurality of tubes which are connected together by means of junction plates welded to the ends of the tubes.