The present invention relates to a method and a wind turbine structure for optimising the weight of the wind turbine and the offshore foundation. The wind turbine is operated based on the measured wave height which in turn allows the tower height to be reduced so that the ratio between the tower height and the length of the wind turbine blades is greater than 0.5. The rotor is parked in a predetermined position with a maximum or minimum clearance between the tip end of the wind turbine blades and the sea level if the measured wave height exceeds a predetermined threshold. A monitoring unit arranged relative to the wind turbine detects if one or more objects are located within a monitoring area. If an object is located within the monitoring area, the wind turbine is shut down and the rotor is rotated to the parked position.

The invention regards an apparatus or method for controlling the profile of a blade on a wind turbine having at least a first blade and a second blade, the first blade comprise at least one first sensor system adapted to determine a first blade state and the second blade comprise at least one second sensor system adapted to determine a second blade state, wherein the profile of the second blade is controlled based on the determined first blade state and the determined second blade state.

A rotor restraining apparatus (200) and methods for a wind turbine (1). The rotor restraining apparatus has a locking element (204) associated with a rotor (8, 203) of the wind turbine, a rotational axis of said rotor defining an axial direction, the locking element being at least part-circular in form. The locking element comprises a plurality of engagement formations (205) disposed on a periphery thereof. The apparatus also has a restraining member (206), comprising a plurality of engagement formations (207). The restraining member is movable substantially along said axial direction between: (a) a non-restraining position; and (b) a restraining position in which the restraining member engagement formations are able to engage the locking element engagement formations. At least a portion of the restraining member has an arcuate form that substantially matches the curvature of the locking element.

A wind turbine (10) includes a main shaft (34) including a front end (34a), the front end (34a) including a first connecting structure (36). A rotor hub (22) includes a second connecting structure (40), wherein the second connecting structure (40) of the rotor hub (22) is fixed to the first connecting structure (36) of the main shaft (34). A plurality of blades (24) is coupled to the rotor hub (22). A rotor locking disc (32) is carried on the main shaft (34), the rotor locking disc (32) having an outer circumference (32a) and a plurality of recesses (50) on the outer circumference (32a), the recesses (50) having openings (50a) intersecting with the outer circumference (32a). At least one rotor locking pin (30) is movable between a disengaged position relative to at least one of the recesses (50) and an engaged position wherein the pin is located at least partially in one of the recesses (50) for locking the rotor hub (22) against rotation.

A method of controlling a wind power plant for generating electrical power from wind is provided. The plant comprises a rotor having rotor blades with adjustable blade angles and the rotor can be operated at a variable rotational speed. The method includes controlling the plant in a partial load mode when wind speed is below a nominal speed and, controlling the plant in a storm mode when the wind speed is above a storm commencement speed. An output power of the plant in the partial load mode and storm mode is adjusted according to an operating characteristic curve that determines a relationship between the rotational speed and the output power. A partial load characteristic curve is used as the operating characteristic curve for controlling the power plant in partial load mode, and a storm mode characteristic curve is used as the operating characteristic curve for controlling the plant in storm mode.

A wind turbine is provided. The turbine includes a support having an axis of rotation, a generator, a plurality of blades rotatably mounted on the support about the axis of rotation, the blades being moveable between a retracted position generally parallel with the axis of rotation and a fully deployed position generally perpendicular with the axis of rotation, the blades being connected to the generator such that rotation of the blades in a direction induced by wind causes the generator to produce electricity, and the provision of electricity to the generator rotates the blades, and a controller connected to the generator and configured to deliver a flow of current to the generator that is sufficient to move the blades from the retracted position toward the fully deployed position and insufficient to move the blades all the way to the fully deployed position. The flow of current induces rotation of the blades in the direction induced by wind, which creates a centrifugal force that moves the blades from the retracted position toward the fully deployed position. As the blades move from the retracted position, the blades have increasing exposure to ambient wind to receive additional rotational force from ambient wind, and the additional rotational force being sufficient to, either alone or in combination with the flow of current, move the blades into the fully deployed position.

Provided is a wind turbine including an active yaw system realized to maintain an upwind orientation of the wind turbine aerodynamic rotor during safe operating conditions, which active yaw system includes a number of yaw drive units, and wherein a yaw drive unit includes a negative brake; a principal power supply configured to supply power to the active yaw system during normal operation of the wind turbine; and a dedicated negative brake reserve power supply configured to supply power to the negative brakes in the event of a grid disconnect. A method of operating such a wind turbine is also provided.

A wind turbine (10) includes a first connecting structure (36) associated with the main shaft (34) fixed to a second connecting structure (40) of a rotor hub (22). A plurality of blades (24) is coupled to the rotor hub (22). A rotor locking disc (32) is carried on the main shaft (34). The rotor locking disc (32) has a peripheral region and a plurality of rotor locking elements (50) in the peripheral region for receiving one or more rotor locking pins (30). The first connecting structure (36) includes at least first and second sets of fastener holes (38a, 38b, 38b′). The first set of fastener holes (38a) is located at a position radially inward of the rotor locking elements (50) and the second set of fastener holes (38b, 38b′) is located between adjacent rotor locking elements (50). The first and/or second set of fastener holes (38a, 38b, 38b′) are used to receive fasteners (39a, 39b) to secure the main shaft (34) to the rotor hub (22).

A method for protecting a wind turbine from extreme and fatigue loads associated with high wind speed events includes receiving, via a wind turbine condition estimator programmed in a turbine controller of the wind turbine, operating data indicative of current wind turbine operation. Further, the method includes determining, via the wind turbine condition estimator, a plurality of estimated wind turbine conditions at the wind turbine by solving a control algorithm having one or more equations using the operating data. The estimated wind turbine conditions include, at least, an estimated wind speed at the wind turbine and a loading proxy of the wind turbine. As such, the method includes implementing, via the turbine controller, a corrective action only when each of the estimated wind turbine conditions indicates that one or more loading conditions of the wind turbine exceeds a predetermined limit.

A wind turbine (10) includes a main shaft (34) including a front end (34a), the front end (34a) including a first connecting structure (36). A rotor hub (22) includes a second connecting structure (40), wherein the second connecting structure (40) of the rotor hub (22) is fixed to the first connecting structure (36) of the main shaft (34). A plurality of blades (24) is coupled to the rotor hub (22). A rotor locking disc (32) is carried on the main shaft (34), the rotor locking disc (32) having an outer circumference (32a) and a plurality of recesses (50) on the outer circumference (32a), the recesses (50) having openings (50a) intersecting with the outer circumference (32a). At least one rotor locking pin (30) is movable between a disengaged position relative to at least one of the recesses (50) and an engaged position wherein the pin is located at least partially in one of the recesses (50) for locking the rotor hub (22) against rotation.