The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

The present invention relates to a blade pitch control apparatus for a small size wind power generator. More specifically, the present invention relates to a blade pitch control apparatus for a small size wind power generator configured to accomplish continuous generation by continuously maintaining the necessary rotating force of the blade by systematically operating the ball screw, spinner driver, and pitch angle controller when the rotation number of blades exceeds the reference rotation number by over wind speed, so that the blade pitch is automatically controlled. To this end, the present invention comprises a blade combined with an outer circumference surface of a rotator, rotating by wind; a spinner box installed and fixed in the middle of the front surface of the blade; a ball screw formed with speed control wings at one end in a state positioned in the longitudinal direction in the middle of the spinner box and having screws at the other end; a spinner driver screw-combined with the screw of the ball screw, and moving to the front and back when the rotation number of blades exceeds the reference rotation number by over wind speed or when the wind speed decreases; and a pitch angle controller connected between the spinner driver and blade, folding and unfolding the blade according to the movement direction of the spinner driver to control the pitch angle of the blade.

Provided are a control method and apparatus for load reduction of a wind turbine. The control method for load reduction includes: determining a representative blade root load value of a wind turbine; determining an additional pitch rate value based on the representative blade root load value; determining a pitch rate control value based on a given pitch rate value and the additional pitch rate value; and applying the pitch rate control value to each blade of the wind turbine, to control each blade of the wind turbine to perform a pitch action.

Systems and methods for determining turbine pressure related loads and for condition monitoring are provided. The systems and methods may measure at least one pressure differential on an airfoil. At least one pressure differential may be used to determine a root bending moment associated with the blade. Additionally or alternatively, at least one pressure differential may be used to determine a low-speed shaft moment for a turbine on which the blade is mounted. Still further, at least one pressure differential and/or moment may be used to gauge wear/fatigue and/or damage to one or more wind turbines. Based on this information, a controller may modify various operating characteristics of the turbine or blade to address the fatigue or damage.

A rotor rotating device includes at least two rotating units; a movable end of a telescoping cylinder in each rotating unit is provided with a pin; the pin is releasably secured on a rotor. A control method for the rotor rotating device includes: dividing the at least two rotating units into two groups; first removing pins of a first group of rotating units from the rotor, and then re-securing the pins at another positions on the rotor; and after the pins of all the rotating units are re-secured, changing the state of the telescoping cylinders of all the rotating units, and driving the rotor to turn relative to a machine base. In this way, all the rotating units are sequentially unlocked, moved to a next working station, and re-locked on the rotor. A control device, and a rotor rotating system are further provided.

The invention relates to a wind turbine system (WTS) comprising at least two blade rotors rotatably mounted to a nacelle (rotatably) mounted to a tower provided above a (water) level. The WTS can be characterised in that the blade rotors are interconnected by one or more retractable blades. The retractable blades can have variable properties, they can be stowable, can be able to weathervane, and can comprise a defined construction, a working mean. The blade rotors can rotate in the same and/or opposite directions. The components can be fabricated of defined materials. The WTS can be provided in an array and it can be couplable or coupled with various mechanocomponents and/or electrocomponents. A method for varying a design point of the disclosed wind turbine is proposed.

An aerofoil module for use in a blade of a propeller or turbine comprising: a body comprising a suction surface and a pressure surface; an air passage traversing the body, the air passage having an entrance opening on the pressure surface and an exit opening on the suction surface; a cover for covering a variable portion of a cross-section of the air passage; and a mechanism for varying the portion of the cross-section of the air passage covered by the cover, wherein the mechanism reacts passively to the oncoming air speed of oncoming air in the axial direction of the propeller/turbine; wherein the mechanism varies the portion of the cross-section covered by the cover such that the cover covers a smaller portion of the cross-section in response to a higher oncoming air speed, and covers a larger portion of the cross-section in response to a lower oncoming air speed.

An aerofoil module for use in a blade of a propeller or turbine comprising: a body comprising a suction surface and a pressure surface; an air passage traversing the body, the air passage having an entrance opening on the pressure surface and an exit opening on the suction surface; a cover for covering a variable portion of a cross-section of the air passage; and a mechanism for varying the portion of the cross-section of the air passage covered by the cover, wherein the mechanism reacts passively to the oncoming air speed of oncoming air in the axial direction of the propeller/turbine; wherein the mechanism varies the portion of the cross-section covered by the cover such that the cover covers a smaller portion of the cross-section in response to a higher oncoming air speed, and covers a larger portion of the cross-section of the air passage in response to a lower oncoming air speed.

A wind turbine is disclosed. The wind turbine includes comprising an inflatable portion comprising one or more blades and a device for rotatably driving the inflatable portion at a predetermined rate for a predetermined time.

A wind turbine is disclosed. The wind turbine includes comprising an inflatable portion comprising one or more blades and a device for rotatably driving the inflatable portion at a predetermined rate for a predetermined time.