A system and method are provided for controlling a wind turbine in response to a blade liberation event. Accordingly, estimated response signatures for the wind turbine are determined. Sensor data indicative of at least two actual response signatures of components of the wind turbine to a rotor loading are collected. The actual response signatures are compared to the estimated response signatures. The two or more actual response signatures meeting or exceeding the estimated response signatures is indicative of a blade liberation event. In response to detecting the blade liberation event, a rapid shutdown control logic is initiated to decelerate the rotor at a rate which exceeds a nominal deceleration rate of the rotor.

A system and method for monitoring and maintaining loading of a yaw brake assembly for use with windmills. A bolt assembly attaches to the yaw brake assembly and provides a compressive load to a brake piston within the yaw brake assembly. A load indicator attached to the bolt assembly provides a measurement of load applied to the brake piston by the bolt assembly.

The invention relates to a method for controlling a wind turbine system, more particular for a controlled sliding strategy to lower loads on the yaw system by controlling mechanical brakes and motor brakes in the yaw drive actuators. When the yaw system being in the non-yawing operational state, and the mechanical brake(s) being in an engaged state, and the yaw controller determines or receives a signal indicative of a yaw moment, and if the signal indicative of a yaw moment is above a signal threshold, then the yaw controller sends a braking signal to the yaw drive actuators to enter the motors into the brake state to apply a braking torque.

A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a chord which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The hinge position is arranged at a distance from the inner tip end (5a) and at a distance from the outer tip end (5b), and the chord at the hinge position is larger than or equal to the chord at the inner tip end (5a) and larger than the chord at the outer tip end (5b).

Systems, methods, and non-transitory computer readable media including instructions for coordinating MPPT operations for a cluster of geographically-associated fluid turbines are disclosed. Coordinating MPPT operations for a cluster of geographically-associated fluid turbines includes receiving data from the cluster of geographically-associated fluid turbines; determining changes to total power output of the cluster based on changes in loading states of individual fluid turbines in the cluster; selecting a combination of loading states for the individual fluid turbines in the cluster to coordinate total power output for the cluster; and transmitting the selected combination of loading states to at least some of the individual fluid turbines in the cluster in order to vary rotational speeds of the at least some of the individual fluid turbines in the cluster.

Systems, methods, and non-transitory computer readable media including instructions for synchronizing a plurality of geographically-associated fluid turbines. Synchronizing a plurality of geographically-associated fluid turbines includes receiving first signals indicative of a phase of a rotational cycle of first rotating blades of a first turbine configured to generate a downstream fluid flow; receiving second signals indicative of a phase of a rotational cycle of second rotating blades of a second turbine configured to receive at least a portion of the downstream fluid flow and generate a differential power output; determining from the first and second signals that greater aggregate power output is achievable through blade phase coordination; determining a phase correction between the first and second rotating blades based on the first and second signals to achieve the greater aggregate power output; calculating coordinating signals based on the phase correction; and outputting the coordinating signals to impose the phase correction.

A method is provided for braking a rotor of a wind turbine. The rotor comprises rotor blades. The wind turbine comprises a pitch adjustment system for adjusting a pitch of the rotor blades. The method comprises detecting a system failure of the pitch adjustment system, estimating a current wind speed, estimating an available brake torque and estimating a required brake torque, based on the estimated current wind speed. The method further comprises determining a suitable point in time for activating a rotor brake, based on the estimated available brake torque and the estimated required brake torque. The rotor brake is then activated at the determined suitable point in time.

A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a loss of traction of the slip coupling between a generator and a rotor of the drivetrain of the wind turbine. In response to detecting the loss of traction, the controller overrides a generator torque setpoint to alter a rotational speed of the generator. In response to the altered rotational speed of the generator, the traction of the slip coupling is increased. Increasing the traction of the slip coupling facilitates an application of generator torque to the drivetrain of the wind turbine.

A system and method are provided for applying a pitch motor braking torque to a rotor blade. Accordingly, of the pitch control system from a 1.sup.st operational mode to an emergency operational mode is initiated. The pitch motor of the pitch control system having an absence of supply current during the transition. A short-circuit is established across the Armature of the pitch motor so as to establish a current flow. The current is generated by the pitch motor in response to rotation of the rotor blade about the pitch axis when the pitch motor has the absence of supply current. In response to the current flow being generated, generating a braking torque in a single direction with the pitch motor so as to allow the rotor blade to move freely to a lesser loaded orientation relative to an original orientation to protect the wind turbine from damage.

The method according to the invention for operating a wind turbine, comprising a tower and a rotor arranged at the top of the tower and having at least one rotor blade, which can be adjusted about a blade setting axis, has a first operating mode which the at least one rotor blade has an operating angular position about the blade setting axis and a wind-force-dependent rotation of the rotor is converted into electrical power using a generator unit, which power is delivered from the wind turbine into an electrical network and/or stored, and a second operating mode in which the at least one rotor blade is adjusted by at least 60° and/or max. 110° about the blade setting axis relative to the operating angular position into a damping angular position, and a counter torque braking the rotor is controlled based on a vibration of the tower.