The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power reference and a pitch system configured to adjust the pitch of a blade of the wind turbine dependent on a pitch request. The control system comprises a controller configured to determine the pitch request dependent on an adjustable gain. A gain scheduler comprised by the control system is configured to set the adjustable gain to an increased gain value if a rate of change of the power reference, e.g. an external power reference, exceeds a threshold.

The invention relates to wind turbines with variable rotor blades whose pitch angle can be adjusted, wherein an adjustment unit for adjusting the pitch angle of a wind turbine rotor blade 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 against each other, and a supply unit for supplying the adjustment actuator with energy, wherein the at least one adjustment actuator and the supply unit are disposed on opposite sides on a plate-shaped adjustment drive carrier part which is directly or indirectly rotatably connected with one of the bearing rings and comprises a rotatable support bearing for the rotatable support of the adjustment actuator on the carrier part. The supply unit is connected with the adjustment actuator by at least one pressurized-media channel passing through the support bearing.

A method for protecting a wind turbine from an extreme change in wind direction includes receiving a wind direction and/or a wind speed at the wind turbine. When a change in the wind direction or the wind speed exceeds a predetermined threshold, the method includes determining a margin to stall and/or zero lift of the at least one rotor blade of the wind turbine as a function of an angle of attack or change in the angle of attack at a blade span location of at least one rotor blade of the wind turbine. The method also includes implementing a corrective action for the wind turbine (without shutting down the wind turbine) when the margin to stall and/or zero lift exceeds a predetermined value so as to avoid stall and/or negative lift on the at least one rotor blade during operation of the wind turbine.

Provided is a system for determining a soiling state of a wind turbine rotor blade. The system includes a pressure sensor adapted to measure a plurality of pressure values corresponding to a plurality of different heights above a trailing edge region of the wind turbine rotor blade, and a processing unit in communication with the pressure sensor and adapted to determine the soiling state of the wind turbine rotor blade by estimating an air flow velocity distribution above the trailing edge region of the wind turbine rotor blade based on the plurality of pressure values. Furthermore, a corresponding method of determining a soiling state of a wind turbine rotor blade is described.

A method for controlling a wind turbine is disclosed, the wind turbine comprising a set of wind turbine blades (1), each wind turbine blade (1) being provided with at least one air deflector (2) being movable between an activated position in which it protrudes from a surface of the wind turbine blade (1) and a de-activated position. The occurrence of an event causing a change in operational conditions is registered, and a new operating state for the wind turbine is determined, the new operating state meeting requirements of the changed operational conditions. The air deflectors (2) of the wind turbine blades (1) and pitch angles of the wind turbines blades (1) are controlled in order to reach the new operating state for the wind turbine, and in such a manner that the control of the pitch angles of the wind turbine blades (1) is performed while taking information regarding the control of the air deflectors (2) into account.

The already patented Madson Wind Turbine System (MWTS) embodies a wind turbine system for the collection of wind energy, compression of air (air or gas) in multi-stages to high pressure, for High PressureCompressed Air Energy Storage (HP-CAES), decompression of air in multi-stages, cooling of hot compressed air, harvesting of compression heat for heating cold decompressed air to increase volume & air flow for more efficient generation of electricity. This new invention constitutes a significant improvement of MWTS thru improved: ability to resist typhoons, cyclones & hurricanes, harvesting & directing hub area wind to the propellers, streamlining of wind for more efficient use by downstream wind turbines, harvesting of compression heat to heat decompressed cold air, simplification of equipment & construction by reducing the number of or combining the function of components, such as, the functions of transfer & regulator valves in previous inventions for lower capital & maintenance costs & greater efficiency; the introduction of new beneficial components, such as, uncloggable transfer valves; the avoidance of hazards, such as, bird strikes & nuisances, such as, flutter, pulse & vertigo and other improvements for the generation, storage and dispatch of electricity. This improvement also includes an HP-CAES Reserve Tank, constructed with Bolted Joints, such that it can be assembled quickly & cheaply without welding, de-stressing & spherical or thick plates; the elimination of, at least, one (1) built-in derrick and the development of self-regulating controls for feathering the propellers adapted to a Fan Wind Turbines instead of the conventional long aspect ratio sails (propellers).

Control methods and systems of a wind turbine belonging to an off-shore wind park that use, in case of malfunction of the load measuring system, one of the following pitch vectors for the calculation of the individual pitch command of each blade: the pitch vector being applied at the same time in one wind turbine of the wind park where the load measuring system works properly a mean value of the pitch vectors being applied at the same time in a group of wind turbines of the wind park where the load measuring system works properly; the pitch vector resulting from a control law, obtained from historic records of the wind turbine when the load measuring system worked properly, defining the pitch vector as a function of at least the wind speed V, if the former pitch vectors are not available.

Disclosed is a method of adaptively adjusting lift and drag on an airfoil-shaped sail. The method includes: (1) mounting at least one airfoil-shaped sail body having an airfoil-shaped cross section; (2) defining a Y-shaped air jet channel in the airfoil-shaped sail body; (3) arranging a flow regulating gate in the Y-shaped air jet channel; (4) adjusting the flow regulating gate to automatically adjust the gate opening extent and the cross section opening or closing extent in response to an oncoming flow with a varying direction and speed, to regulate the airflow within the air jet channel and accordingly change the angle of attack, so that the lift and drag on the sail body can be automatically adjusted as the wind speed changes. Further disclosed are an airfoil-shaped sail implementing the above method as well as a vertical-axis wind turbine employing the airfoil-shaped sail.

A vertical axis wind turbine includes two or more cells arranged one above the other along a vertical machine axis, wherein each of the cells includes a plurality of vertical blades which are arranged within the cell distributed on a concentric circle about the machine axis and which are connected so as to be able to move together on this circle and which are rotationally fixed with a main shaft, and wherein the blades in the cell are each individually mounted so as to be able to rotate about a vertical axis of rotation which in particular runs internally through them.

The present invention relates to a control system for thrust-limiting of wind turbines, which wind turbine comprises at least one tower, which tower carries at least one nacelle which nacelle comprises a rotating shaft, which shaft is rotated by one or more blades, which blades at pitch regulated by a pitch control system. It is the object of the present invention to reduce mechanical load and stress of a wind turbine. A further object is to reduce the maximal load on tower of a wind turbine. The thrust-limiting control system performs control of the pitch angle, which thrust-limiting control system performs regulation of the pitch angle based on at least a first input from a wind estimator and a second input from a turbulence estimator. By thrust-limiting control, reduction in the maximum mechanical load on a tower, or maybe also a nacelle, can be achieved by a relatively high percentage of the load in a way where it has only very limited influence on the power production of the wind turbine.