FLOATING WIND TURBINE SYSTEMS AND METHODS
A method of operating a downwind floating wind turbine comprising the downwind floating wind turbine floating in a body of water assuming mean heel angle within a range, the mean heel angle defined by a mean pitch angle of a central axis Y of a tower of the downwind floating wind turbine in a direction of wind; and the downwind floating wind turbine operating with a maximum rotor misalignment from a horizontal axis that is perpendicular to gravity while assuming the mean heel angle. The tower includes a turbine with a nacelle, hub and a plurality of blades extending from the hub, the plurality of blades configured to rotate about a rotor axis R, the rotor axis R having rotor tilt angle defined by an angle of rotor axis R relative to a perpendicular axis to the central axis Y.
1 . A method of operating a downwind floating wind turbine, the method comprising:
the downwind floating wind turbine floating in a body of water passively assuming mean heel angle of equal to or between 8° and 10° defined by a mean pitch angle of a central axis Y of a tower of the downwind floating wind turbine in a direction of wind, the downwind floating wind turbine passively assuming the mean heel angle from a force generated by the wind; and
the downwind floating wind turbine operating with a maximum rotor misalignment between −1° and −7° degrees from a horizontal axis that is perpendicular to gravity while assuming the mean heel angle of equal to or between 8° and 10°,
wherein the downwind floating wind turbine comprises:
the tower that includes a turbine with a nacelle, hub and a plurality of blades extending from the hub, the plurality of blades configured to rotate about a rotor axis R, with the plurality of blades having a blade plane B that is perpendicular to the rotor axis R, the rotor axis R having static tilt angle defined by an angle of rotor axis R relative to a perpendicular axis to the central axis Y with the downwind floating wind turbine having a static tilt angle of between 3° and 7° such that the rotor axis R has a misalignment of between 3° and 7° degrees in a vertical position, and°
a hull assembly that includes:
a central column coupled to a base of the tower at a top of the central column, the central column having a central column axis coincident with the central axis Y,
a plurality of at least three outer columns including a first outer column, a second outer column and a third outer column, the plurality of at least three outer columns surrounding and equally spaced about the central column about the central axis Y;
a plurality of upper truss members, including at least a first upper truss member, a second upper truss member and a third upper truss member that respectively couple the first, second and third outer columns with the central column;
a plurality of lower truss members including at least a first lower truss member, a second lower truss member and a third lower truss member that respectively couple the first, second and third outer columns with the central column; and
a plurality of cross-beams, including at least a first-cross beam, a second cross-beam and a third cross-beam, that respectively couple and extend diagonally between the first, second and third outer columns and the central column,
wherein the downwind floating wind turbine is configured to assume an erected configuration passively floating in the body of water, on a surface of the body of water without being coupled to a floor of the body of water, where the tower extends vertically above the surface of the body of water with the three outer columns and the central column partially submerged in the body of water, with the downwind floating wind turbine floating in the body of water at least based on buoyancy of the three outer columns and the central column.
2 . The method of operating the downwind floating wind turbine of claim 1 , wherein a rotor tilt angle is configured to be changed.
3 . The method of operating the downwind floating wind turbine of claim 2 , wherein the downwind floating wind turbine is configured to operate as a teetering downwind floating wind turbine and comprises a teetered hub that allows a rotor tilt angle to be changed.
4 . The method of operating the downwind floating wind turbine of claim 1 , wherein the central column and the three outer columns are configured to be filled with water that acts as ballast for the hull assembly.
5 . A method of operating a downwind floating wind turbine comprising:
the downwind floating wind turbine floating in a body of water passively assuming mean heel angle of equal to or between 8° and 10° defined by a mean pitch angle of a central axis Y of a tower of the downwind floating wind turbine in a direction of wind, the downwind floating wind turbine passively assuming the mean heel angle from a force generated by the wind; and
the downwind floating wind turbine operating with a maximum rotor misalignment between −1° and −7° degrees from a horizontal axis that is perpendicular to gravity while assuming the mean heel angle of equal to or between 8° and 10°,
wherein the tower includes a turbine with a nacelle, hub and a plurality of blades extending from the hub, the plurality of blades configured to rotate about a rotor axis R, with the plurality of blades having a blade plane B that is perpendicular to the rotor axis R, the rotor axis R having rotor tilt angle defined by an angle of rotor axis R relative to a perpendicular axis to the central axis Y, with the downwind floating wind turbine having a static tilt angle of between 3° and 7° such that the rotor axis R has a misalignment of between 3° and 7° degrees in a vertical position.
6 . The method of operating the downwind floating wind turbine of claim 5 , wherein the downwind floating wind turbine comprises:
a hull assembly that includes:
a central column coupled to a base of the tower at a top of the central column, the central column having a central column axis coincident with the central axis Y,
a plurality of at least three outer columns including a first outer column, a second outer column and a third outer column, the plurality of at least three outer columns surrounding and equally spaced about the central column about the central axis Y;
a plurality of upper truss members, including at least a first upper truss member, a second upper truss member and a third upper truss member that respectively couple the first, second and third outer columns with the central column;
a plurality of lower truss members including at least a first lower truss member, a second lower truss member and a third lower truss member that respectively couple the first, second and third outer columns with the central column; and
a plurality of cross-beams, including at least a first-cross beam, a second cross-beam and a third cross-beam, that respectively couple and extend diagonally between the first, second and third outer columns and the central column.
7 . The method of operating the downwind floating wind turbine of claim 5 , wherein the downwind floating wind turbine is configured to assume an erected configuration floating in the body of water, on a surface of the body of water without being coupled to a floor of the body of water, where the tower extends vertically above the surface of the body of water with a plurality of outer columns submerged in the body of water, with the downwind floating wind turbine floating in the body of water at least based on buoyancy of the plurality of outer columns.
8 . A method of operating a downwind floating wind turbine comprising:
the downwind floating wind turbine floating in a body of water assuming mean heel angle within a range, the mean heel angle defined by a mean pitch angle of a central axis Y of a tower of the downwind floating wind turbine in a direction of wind; and
the downwind floating wind turbine operating with a maximum rotor misalignment from a horizontal axis that is perpendicular to gravity while assuming the mean heel angle,
wherein the tower includes a turbine with a nacelle, hub and a plurality of blades extending from the hub, the plurality of blades configured to rotate about a rotor axis R, the rotor axis R having rotor tilt angle defined by an angle of rotor axis R relative to a perpendicular axis to the central axis Y.
9 . The method of operating the downwind floating wind turbine of claim 8 , the downwind floating wind turbine passively assumes the mean heel angle from a force generated by the wind.
10 . The method of operating the downwind floating wind turbine of claim 8 , wherein the mean heel angle is equal to or between 5° and 15°.
11 . The method of operating the downwind floating wind turbine of claim 8 , wherein the maximum rotor misalignment between 1° and 13° degrees.
12 . The method of operating the downwind floating wind turbine of claim 8 , wherein the rotor tilt angle is equal to or between 1° and 10°
13 . The method of operating the downwind floating wind turbine of claim 8 , wherein the downwind floating wind turbine comprises a hull assembly that includes a plurality of at least three outer columns including a first outer column, a second outer column and a third outer column.
14 . The method of operating the downwind floating wind turbine of claim 8 , wherein the downwind floating wind turbine is configured to assume an erected configuration floating in the body of water, on a surface of the body of water without being coupled to a floor of the body of water, where the tower extends vertically above the surface of the body of water with a plurality of columns submerged in the body of water, with the downwind floating wind turbine floating in the body of water at least based on buoyancy of the plurality of columns.
15 . The method of operating the downwind floating wind turbine of claim 8 , wherein the mean heel angle is equal to or between 1° and 20°.
16 . The method of operating the downwind floating wind turbine of claim 8 , wherein the maximum rotor misalignment is between 2° and 20°.
17 . The method of operating the downwind floating wind turbine of claim 8 , wherein the rotor tilt angle is configured to be changed.
18 . The method of operating the downwind floating wind turbine of claim 17 , wherein the downwind floating wind turbine is configured to operate as a teetering floating wind turbine and comprises a teetered hub that allows the rotor tilt angle to be changed.
19 . A method of operating a downwind floating wind turbine comprising:
the downwind floating wind turbine floating in a body of water passively assuming mean heel angle of equal to or between 14° and 16° defined by a mean pitch angle of a central axis Y of a tower of the downwind floating wind turbine in a direction of wind, the downwind floating wind turbine passively assuming the mean heel angle from a force generated by the wind; and
the downwind floating wind turbine operating with a maximum rotor misalignment between −1° and 1° degrees from a horizontal axis that is perpendicular to gravity while assuming the mean heel angle of equal to or between 14° and 16°,
wherein the tower includes a turbine with a nacelle, hub and a plurality of blades extending from the hub, the plurality of blades configured to rotate about a rotor axis R, with the plurality of blades having a blade plane B that is perpendicular to the rotor axis R, the rotor axis R having rotor tilt angle defined by an angle of rotor axis R relative to a perpendicular axis to the central axis Y, wherein the rotor tilt angle of is between 3° and 7°, with the downwind floating wind turbine having a static tilt angle of 3° and 7° such that the rotor axis R has a misalignment of between 3° and 7° in a vertical position.