A wind turbine comprises a hub, a blade rotatably mounted to the hub, and a pitch system. The pitch system includes a support, a first drive configured to rotate the blade relative to the support, a second drive configured to rotate the support relative to the hub. The support is configured to be selectively fixed relative to the blade and the hub such that the first or second drive may be used to pitch the blade. A method of pitch corresponding to this operation is provided.

Wind turbine pitch actuator mounting structure A mounting structure is described for attaching a pitch actuator to a hub of a wind turbine. The mounting structure has one or more legs each having a proximal end and a distal end, and a flexible intermediate portion between the proximal and distal ends. The mounting structure further comprises an actuator attachment portion for attaching to a wind turbine blade pitch actuator. The actuator attachment portion is arranged at the distal end(s) of the one or more legs. The proximal end(s) of the one or more legs are configured for attachment to a wind turbine hub. The flexible intermediate portion(s) of the one or more legs are configured to flex in use to absorb loads acting on the pitch actuator. The mounting structure therefore allows the pitch actuator to pivot in a first plane by virtue of the flexible legs. The pitch actuator may be attached to the mounting structure via pivot bearings arranged to allow the pitch actuator to pivot in a second plane, substantially perpendicular to the first plane.

A pitch control method and system of a symmetrical-airfoil vertical axis wind turbine is provided, which collects data by an anemometer, an anemoscope and an angle sensor, outputs an optimum pitch angle based on a control law of a pitch angle, and controls the pitch angle to be the optimum pitch angle through a pitch control actuator. In addition to input variables of the control law such as a wind velocity v.sub.in and a blade azimuth angle Ψ, constants such as a rotation radius R, a rotation velocity Ω of the blade and aerodynamic coefficients c.sub.1, c.sub.2 and c.sub.3 are also related. A Reynolds number has little influence on three aerodynamic coefficients c.sub.1, c.sub.2 and c.sub.3. The pitch actuator controls the adjustment rods to realize the automatic pitch control of the blades. An expression of the control law of the pitch is concise, the calculation time is short and a response speed is fast.

A pitch varying device, a pitch varying method and a pitch varying control device for a wind turbine blade and a wind turbine are provided. The blade pitch varying device includes: a disc-type driving structure perpendicular to an axis of a pitch bearing, a track surrounding the axis of the pitch bearing being provided on the disc-type driving structure; a first linear telescopic driving mechanism connected to the track through a first clamping member capable of clamping the track, and the first linear telescopic driving mechanism and the first clamping member being connected through a hinge connection; and a second linear telescopic driving mechanism connected to the track through a second clamping member capable of clamping the track, and the second linear telescopic driving mechanism and the second clamping member being connected through a hinge connection.

Provided is a wind turbine including: at least a rotor blade including an aerodynamic device for influencing the airflow flowing from the leading edge section of the rotor blade to the trailing edge section of the rotor blade, wherein the aerodynamic device is mounted at a surface of the rotor blade, a pressure supply system for providing a pressurized fluid for operating the aerodynamic device between a first protruded configuration and a second retracted configuration, a control unit for controlling the pressure supply system, a monitor unit for monitoring a pressure and/or a flow rate of the pressurized fluid, and configured for: receiving a measured pressure and/or flow rate signal in at least one section of the pressure supply system, deriving an operative status of the aerodynamic device based on the measured pressure and/or flow rate signal.

This invention discloses in particular an actuation cylinder (10) for controlling the movement of a ring-gate (40) of a hydraulic machine, said actuation cylinder (10) comprising a body (18) forming a first chamber (22) provided with a first duct (26) and a second chamber (24) provided with a second duct (28) which are designed to receive an actuating fluid through said first duct (26) and said second duct (28), said chambers being separated from one another by a piston (20) connected to an actuating rod (14) and able to move in said body in a first direction in which the volume of the second chamber increases while the volume of the first chamber decreases, and in a second direction in which the volume of the second chamber decreases while the volume of the first chamber increases, said piston being provided with a rod (30) connected in said second chamber to an area (20b) of the piston turned toward said second chamber, said area (20b) having a surface less than an area (20a) of the piston turned toward the first chamber.

This invention regards a hydraulic turbine (1) to operate in pressure circuits, where there is a flow of a fluid, to control the flow and pressure downstream the installation point. Even so, said turbine (1) can generate power for itself based on the difference of pressure and flow, as the remaining power can be used in public power networks or isolated. Its application field comprises sanitation companies, beverage industries, paper and cellulose industries, petrochemical companies or any places, where it is needed to control the flow and pressure in supply networks.

A pitch varying device, a pitch varying method and a pitch varying control device for a wind turbine blade and a wind turbine are provided. The blade pitch varying device includes: a disc-type driving structure perpendicular to an axis of a pitch bearing, a track surrounding the axis of the pitch bearing being provided on the disc-type driving structure; a first linear telescopic driving mechanism connected to the track through a first clamping member capable of clamping the track, and the first linear telescopic driving mechanism and the first clamping member being connected through a hinge connection; and a second linear telescopic driving mechanism connected to the track through a second clamping member capable of clamping the track, and the second linear telescopic driving mechanism and the second clamping member being connected through a hinge connection.

A control method for a hydraulic control turning system of a generator rotor includes: establishing a length relationship table between multiple hydraulic cylinders of the hydraulic control turning system; selecting a reference hydraulic cylinder; acquiring current lengths of the multiple hydraulic cylinders when the multiple hydraulic cylinders are located at error correction positions; and adjusting lengths of the other hydraulic cylinders corresponding to a next driving stroke to conform with the length relationship table. With such an arrangement, the accumulated dimension error between the hydraulic cylinders may be dynamically corrected during the turning operation, thereby ensuring that the turning pins are accurately aligned with the pin holes in the generator, and the corresponding turning operation is performed after the generator set is locked. Based on this, a control device for a hydraulic control turning system of a generator rotor is further provided.

A drive assembly for adjusting the pitch of a wind turbine blade comprises a stator having a cylindrical body and a drive member positioned at least partially within the cylindrical body and movable along an axis thereof. A mounting pin extends through an aperture in a wall of the cylindrical body for pivotally mounting the stator to a wind turbine structure.