A method for controlling a wind turbine having rotor blades with an adjustable blade angle, comprising the steps operating the wind turbine in a partial load mode for wind velocities up to a nominal wind velocity, wherein in the partial load mode, a fixed partial load angle is provided for the blade angle, operating the wind turbine in a full load mode for wind velocities above the nominal wind velocity, wherein in the full load mode the blade angle is enlarged with increasing wind velocity and has values above the partial load angle, and wherein in the partial load mode, starting from a predetermined operating state, the blade angle is reduced as compared with the partial load angle.

A method, device and system for determining angle-to-wind deviation and correcting angle-to-wind; the method for determining angle-to-wind deviation comprises: obtaining historical operation data of a wind turbine group during a specific time period (S101); determining an angle-to-wind deviation value for each wind speed segment on the basis of the acquired historical operation data (S102); for any wind speed segment, determining the angle-to-wind deviation value on the basis of the actual angle-to-wind measurement value and the output power value of an environmental wind speed value at a time point within the specific time period.

A counterweight system for mounting a rotor blade on a balanced rotatable hub of a wind turbine is disclosed. The rotatable hub can have at least one blade root region configured to receive a blade root of the rotor blade, and also have a pitch system configured to rotate the rotor blade around a pitch axis. The counterweight system can have at least one support structure having a proximal end spaced apart from a distal end with the proximal end mountable to at least one blade root region of the rotatable hub. The at least one counterweight mass can be at least partially filled with fluid and coupled to the distal end of the at least one support structure. The at least one support structure can be arranged substantially parallel to the pitch axis such that the pitch system rotates the counterweight mass about the pitch axis.

A method and a device for use in variable-pitch control of a wind turbine, in said method: if a current wind speed is continuously maintained at a small wind speed, then periodically detecting whether a maintained duration of a current pitch angle of a wind turbine reaches a preset duration; once the preset duration is reached, switching a current minimum pitch angle to another minimum pitch angle.

A method for monitoring a bank of ultracapacitors configured to power an alternating current (AC) pitch motor of a pitch system in a wind turbine is provided. The method includes obtaining, by one or more control devices, data indicative of a voltage associated with the bank of ultracapacitors. The method includes conducting, by the one or more control devices, a test operation of the bank of ultracapacitors at predetermined intervals of time to determine a capacitance associated with the bank of ultracapacitors. The method further includes performing, by the one or more control devices, one or more control actions based, at least in part, on the capacitance or the data indicative of the voltage.

There is presented a wind turbine system, wherein the wind turbine system is comprising a support structure, a plurality of wind turbine modules mounted to the support structure wherein each of the plurality of wind turbine modules comprises a rotor, and wherein the wind turbine system further comprises a control system, wherein the control is arranged to execute a wind turbine system transition from a first system operational state of the wind turbine system to a second system operational state of the wind turbine system, and wherein the wind turbine system transition is performed by executing a plurality of wind turbine module transitions from a first module operational state of a wind turbine module to a second module operational state of the wind turbine module wherein the plurality of wind turbine module transitions are distributed in time with respect to each other.

The present invention relates to wind turbines with variable rotor blades whose pitch angles are adjustable. An adjustment unit is provided for adjusting the pitch angle of the rotor blades with a pivot bearing comprising at least two coaxial bearing rings that are rotatable against each other, at least one adjustment actuator for rotating the two bearing rings, and a supply unit for supplying the adjustment actuator with energy, whereby the adjustment actuator and the supply unit are disposed on opposite sides on a plate-shaped adjustment drive carrier part which is rotatably connected with one of the bearing rings and comprises a rotatable support bearing for the support of the adjustment actuator. A least one part of the supply unit is rotatably mounted on the carrier part such that the supply unit or its rotatably mounted part and the adjustment actuator are jointly rotatably mounted and/or swivel-mounted on the carrier part.

The invention relates to control of a wind turbine comprising a plurality of multi-axial accelerometers mounted at different positions in the nacelle and/or in a top portion of the tower. The position and orientation of each accelerometer as mounted is obtained, accelerations in at least two different directions by each accelerometer are measured during operation of the wind turbine. From a number of predetermined mode shapes for the movement of the wind turbine is then determined an absolute position of at least one of the accelerometers during operation of the wind turbine based on the measured accelerations, the mount position and orientation of each accelerometer and the pre-determined mode shapes. Hereby a more precise absolute position during operation is obtained which can be used in the controlling of the turbine.

The present invention relates to a method and wind turbine for determining a dynamic twist of one or more blades. One or more first signals are received from a first wireless sensor attached to a blade of a wind turbine and a first angle is determined based on the received first signals. One or more second signals are received from a second wireless sensor attached to a blade of a wind turbine and spaced apart from the first wireless sensor by a predetermined distance. A second angle is determined based on the received second signals. A dynamic twist of the blade is determined based on the determined first angle, the determined second angle and the predetermined distance.

A kinetic fluid energy conversion system comprises one or more hubs which rotate about a central hub carrier, each including one or more independently controlled articulating energy conversion plates (ECP). An articulation control system rotates each ECP independently of all others to control its orientation with respect to the fluid flow direction between an orientation of 90 perpendicular to the fluid flow, while traveling in the direction of the flow and 0 minimal drag parallel position to the flow, while traveling in the direction against the flow or blocked from it. Each hub can be operably coupled to another hub to form one or more counter-rotating hub and ECP assemblies whereby the mechanical energy is transferred through the hubs, to one or more clutch/gearbox/generator/pump assemblies thereby permitting such assemblies to be land-based when the system is air-powered, and above or near the surface, when the system is water-powered.