A method for controlling a wind turbine, the wind turbine having a generator with controllable generator torque and an aerodynamic rotor with rotor blades with adjustable pitch angle, the aerodynamic rotor driving the generator with variable rotor speed depending on a wind speed, comprising the steps operating the wind turbine in a subrated mode when the wind speed is below a predetermined rated wind speed, operating the wind turbine in a rated mode when the wind speed is at or above the predetermined rated wind speed, estimating the wind speed and operating the wind turbine in subrated mode or in rated mode in dependence on the estimated wind speed.

A vertical axis turbine having a first rotor and at least one second rotor, the first rotor being configured to rotate around a first rotation axis that is vertical or more vertical than horizontal, in use. The first rotor may be configured to be driven and/or rotated by fluid motion, e.g. by wind or water flow. The at least one second rotor is provided on or coupled to the first rotor such that the first rotor is operable to move the second rotor through the fluid and thereby drive the second rotor upon rotation of the first rotor. The second rotor is operable to drive a power take off system. Optionally, rotation of the first rotor around the first rotation axis moves the second rotor around the first rotation axis. Each second rotor rotates around a respective second rotation axis that may be angled or perpendicular to the first rotation axis of the first rotor and is optionally a horizontal axis or at least an axis that is more horizontal than vertical, in use. The first and second rotors are configured so that the power take-off is by direct drive without the need for a gearbox or multi-pole generator. The first and second rotors are configured so that the power conversion of mechanical power at the first rotor is converted to mechanical power at the second rotors has high efficiency.

A rotor for a wind turbine, in particular a wind turbine, having a power of more than 1 MW, to a hub for a rotor of a wind turbine and to a wind turbine. A rotor for a wind turbine, in particular a wind turbine having a power of more than 1 MW, comprising a primary rotor blade, wherein the primary rotor blade extends from a first root region to a first blade tip having a first longitudinal extension, a secondary rotor blade, wherein the secondary rotor blade extends from a second root region to a second blade tip having a second longitudinal extension, the first longitudinal extension being larger than the second longitudinal extension.

Provided is a blade for a wind turbine, the blade including a joint section configured to connect the blade to a hub of the wind turbine; an active add-on member which is actuated by a corresponding trim actuator to alter aerodynamic properties of the blade; and a channel configured to supply a medium from the joint section to the active add-on member. A wind turbine and a method of preventing icing of the blade is also provided.

The present invention discloses a hybrid generator. The hybrid generator according to one embodiment of the present invention includes a housing having an empty space through which a fluid flows; a rotor received inside the housing, rotated by a fluid flowing inside the housing, and having a magnet; and a stator coupled between the housing and the rotor, surrounding the rotor, and having at least one coil. According to the present invention, the rotor includes a rotating shaft having a first blade on the outer circumferential surface thereof, and further includes a second blade detachably coupled to the rotating shaft.

The Vertical Tilting Blade Turbine Windmill device is for capturing kinetic energy from the wind and is comprised of a vertical shaft having a central hub connectively attached, the central hub having a plurality of wind capture arms comprising a rotating wind capture blade having a capture surface and a slicing edge that are rotated by a rotating gear and drive gear combination connectively attached to said wind capture blades enabling a rotation of said wind capture blades wherein the wind capture blades are rotated between a blade-mode to capture the wind and a knife-mode to pass with less drag resistance through the air/wind thereby enabling an increase in the ability to capture more of the energy available in an on-coming wind stream.

A method of operating a wind energy installation having a rotor with at least one rotor blade that is angularly adjustable by an adjustment drive. In response to the occurrence of at least one special operating case, in particular at least one malfunction case, the rotor blade is adjusted in a direction of a shutdown position by the adjustment drive. In the shutdown position, a supply of energy from an energy storage device to the adjustment drive is switched off and/or a pitch brake for holding the rotor blade in its current position is closed. In response to at least one activation signal, the rotor blade is adjusted by the adjustment drive in an adjustment mode of operation while the special operating case is still ongoing, in particular while the malfunction case is still ongoing.

A method of operating a wind turbine during a service, wherein the wind turbine comprises at least one rotor-nacelle assembly, the or each rotor-nacelle assembly comprising a rotor; the method comprising: detecting that a service is to be or is being carried out on the wind turbine; and, on detecting that a service is to be or is being carried out on the wind turbine, reducing an operating level of the or each rotor-nacelle assembly.

A method of operating a wind energy installation wherein a rotor has a first rotor blade which can be angularly adjusted, a first adjustment drive for adjusting the rotor blade, and a safety control system. In a normal mode of operation, the first adjustment drive is supplied with energy from a source and is controlled by a first pitch control system. In a failure mode of operation, the supply of energy to the first adjustment drive is switched from the source to an energy storage device and the safety control system monitors a position and/or movement of the first rotor blade. The first rotor blade is adjusted by the first adjustment drive in a direction of a predetermined stopping position, while the safety control system, as a function of the monitored position and/or movement, enables or effects a deactivation of a first power supply shut-off device. In the failure mode of operation, the safety control system, as a function of the monitored position and/or movement, closes a first pitch brake and activates a first blocking mode in which the supply of energy to the first adjustment drive from the energy storage device and/or an opening of the first pitch brake is prevented.

Even when a low stiffness blade is adopted, collision between the blade and a tower is avoided when a wind power generation apparatus is to be stopped, while an increase in the time required for the stop is suppressed. A rotor including a blade, a nacelle that supports the rotor, a tower that supports the nacelle, a pitch angle control mechanism that controls a pitch angle of the blade, and a controller that outputs a target value of the pitch angle to the pitch angle control mechanism are included. When the wind power generation apparatus is to be stopped, the controller determines the target value of the pitch angle in a feather operation of the blade such that the blade does not greatly bend toward the tower in an azimuth angle range in which the blade passes through the tower.