A wine turbine with blades having a high lift-to-drag ratio is provided A hydraulic or other control system is used to control cone angle, such as in response to flap moment Pitch of blades is controlled, such as in relation to the blade flap angle Teeter motion is controlled preferably as a function of teeter angular velocity

Rotor device and control for wind turbine

The invention relates to a wind power plant with a tower, a rotor having at least one rotor blade being substantially radially distant with respect to a rotor axis and being rotatably supported with respect to a substantially horizontal rotation axis in a portion at the top of said tower, preferably at machine nacelle rotatably supported on a rotation axis extending substantially along the gravitational direction, a sensor means associated to said rotor for generating sensor signals depending on the mechanical load of the rotor, and an analysis means, especially a data processing means, wherein at least two, preferably pair-wise mounted, sensor elements are associated to at least one, preferably to each, rotor blade of the rotor and the evaluation means is designed for determining evaluation signals representing the mechanical loads of at least one rotor blade on the basis of the sensor signals generated by the sensor elements associated to this rotor blade.

Wind turbine having sensor elements mounted on rotor blades

A wind-driven electric generator of the downwind type has a wind turbine rotor with oppositely disposed flexible blades attached to the hub of a drive shaft by a flexible spar extending from the hub into hollow portions of the blades. The ends of the spar are attached to intermediate regions of the blades by respective ball joints. Each blade has a root-rib with a stub shaft that is slidably supported in a ball joint mounted on the hub. The blades are pitched to a stall position by a collective pitch mechanism in the absence of proper operating conditions. A nacelle cover of the wind turbine defines an airflow path through the head, and an airflow responsive device inside the nacelle cover controls the collective pitch mechanism to place the blades in a stall position or run position depending upon predetermined airflow conditions. A reverse-cone prevention device limits the ability of the blades to cone reversely.

Wind-driven electric generator apparatus of the downwind type with flexible changeable-pitch blades

A rotor (16) for a wind energy turbine (10) includes a hub (18) defining an inner space (34) and at least one rotor blade (20) defining an inner space and having a tip (22) and a root (24) attached to the hub. The inner spaces of the hub and the at least one rotor blade are in fluid communication. The rotor further includes air flow (26) means for causing air to flow out of the hub and into the at least one rotor blade.

Rotor for a wind energy turbine and method for controlling the temperature inside a rotor hub

Control features for a wind turbine that control the turbine over a range of wind speeds and under triggering conditions with reduced noise, cost, and reliability issues associated with other such controls. Control is accomplished via control electronics, which adjust the torque produced by the electrical output generation device (e.g., alternator) within the wind turbine. During normal operation, torque is adjusted for optimum aerodynamic performance and maximum output of power. In winds above rated power, the control circuit regulates torque to lower aerodynamic performance, as necessary to maintain desired power level output. In triggering conditions, such as during simultaneous control circuit failure and loss of some portion of the electrical output generation device in extreme winds, wind turbine control is accomplished by increasing torque (e.g., via a separate controller) from the electrical output generation device via shorting of windings, so as to cause retardation of blade rotation.

Stall controller and triggering condition control features for a wind turbine

A rotor hub is provided for coupling a wind turbine rotor blade and a shaft. The hub has a yoke with a body which is connected to the shaft, and extension portions which are connected to teeter bearing blocks, each of which has an aperture. The blocks are connected to a saddle which envelops the rotor blade by one or two shafts which pass through the apertures in the bearing blocks. The saddle and blade are separated by a rubber interface which provides for distribution of stress over a larger portion of the blade. Two teeter control mechanisms, which may include hydraulic pistons and springs, are connected to the rotor blade and to the yoke at extension portions. These control mechanisms provide end-of-stroke damping, braking, and stiffness based on the teeter angle and speed of the blade.

Joseph Jankowski

Papers

Wind turbine rotor hub and teeter joint