Provided is an arrangement for controlling inflow and outflow of a fluid into and out of an expandable container arranged to change a state of an adaptable flow regulating device installed at a wind turbine rotor blade, the arrangement including: an inflow valve arranged to control fluid inflow into the container; an outflow valve arranged to control fluid outflow out of the container; wherein the inflow valve and the outflow valve are configured to prohibit fluid flow into and/or out of the container in case of safety stop event.

Provided is an adaptable spoiler for a wind turbine rotor blade, including: a base element adapted to be connected at or integrated with a rotor blade; an airfoil element being attachable to the base element and having an airfoil shaped surface to be exposed to an air flow.

Provided is an adaptable spoiler for a wind turbine blade, including: a flexible body including: an outer surface to be exposed to air flow; an internal surface limiting a cavity to be inflated with fluid to different level, wherein a shape and/or position and/or orientation of the surface to be exposed to air flow changes upon inflating the cavity to different level.

Provided is a device and a method of damping front and backward movements of a tower of a wind turbine, wherein the wind turbine includes the tower and a rotor, the rotor being mounted at the top of the tower to rotate about a rotational axis in which the front and backward movements of the tower occur, and the rotor has a plurality of blades, wherein each blade has at least one corresponding active add-on member which is actuated by a corresponding actuator to alter aerodynamic properties of the blade. Each add-on member is actuated by the corresponding actuator to alter the aerodynamic properties of the blade in a manner that the rotor is configured to damp the front and backward movements of the tower of the wind turbine.

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.

Provided is a method of estimating a value of wind speed a wind turbine is subjected to, the wind turbine having a rotor with rotor blades at least one having an adaptable flow regulating device installed, the method including: obtaining values for power output of the wind turbine, rotor speed of the rotor, and pitch angle of the rotor blades; obtaining state information of the adaptable flow regulating device; and estimating the value of the wind speed based on the values for power output, rotor speed, pitch angle and the state information of the adaptable flow regulating device.

Provided is a method of correcting a measurement value of least one wind characteristic, in particular wind speed and/or wind direction, related to a wind turbine having a rotor with plural rotor blades at least one having an adaptable flow regulating device installed, the method including: measuring a value of the wind characteristic; obtaining state information of the adaptable flow regulating device; and determining a corrected value of the wind characteristic based on the measured value of the wind characteristic and the state information of the adaptable flow regulating device.

A rotor blade of a wind turbine including an aerodynamic device which can be actuated pneumatically by the use of a pressure supply system is provided. The pressure supply system includes a pressurized air supply system, a pressurized air transmission system with pressure lines for transmitting the supplied pressurized air from the pressurized air supply system to the aerodynamic device, at least one pneumatic actuator for activating the aerodynamic device, and a safety system to protect the rotor blade from damages caused by overpressure in the pressurized air transmission system and/or the actuator. The safety system includes means for discharging pressurized air from the pressurized air transmission system and/or the actuator. Also provided is a wind turbine for generating electricity including at least one such rotor blade.

A wind turbine including: a pressure supply system for operating the actuator of at least an aerodynamic device by means of a pressurized gas, wherein the pressure supply system includes: a pressure generator for pressurizing the pressurized gas, a pressure supply line connecting the pressure generator and the pneumatic actuator for providing the pressurized gas to the pneumatic actuator, the pressure supply line including a pressure reservoir, a return line connecting the pressure generator and the pneumatic actuator for returning the pressurized gas to the pressure generator, the return line including a return reservoir having a negative relative pressure, is provided.

A method of controlling a wind turbine including a plurality of rotor blades, a first controller for controlling an adaptive flow regulating system having a plurality of individually controllable adaptive flow regulating devices arranged on the rotor blades, and a second controller for controlling a pitch regulating system for regulating a pitch angle of each rotor blade. The method includes (a) determining a diagnostic value indicative of an operational efficiency of the adaptive flow regulating system, (b) determining a first gain value for the first controller and a second gain value for the second controller based on the diagnostic value, (c) applying the first gain value to control signals for the adaptive flow regulating system generated by the first controller, and (d) applying the second gain value to control signals for the pitch regulating system generated by the second controller, is provided.