The invention relates to a method for controlling a wind turbine in partial and full load. In order to avoid disadvantages of switching between partial and full load controllers, the wind turbine control system is configured so that both the partial and full load controller provides control action during partial and full load. For that purpose, the partial and full load controllers are configured with variable gains, wherein gain scheduling is performed so that the gain of partial load controller is larger than the gain of the full load controller during partial load and vice verso so that the gain of the full load controller is larger than the gain of the partial load controller during full load.

A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a transient grid event and generates a torque command via a drive-train-damper control module. The torque command is configured to establish a default damping level of a torsional vibration resulting from the transient grid event. The controller also determines at least one oscillation parameter relating to the torsional vibration and determines a target generator torque level based thereon. The target generator torque level corresponds to an increased level of damping the torsional vibration relative to the default damping level.

A system and method are provided for controlling a wind turbine to protect the wind turbine from anomalous operations. Accordingly, in response to receiving data indicative of an anomalous operational event of the wind turbine, the controller initiates an enhanced braking mode for the wind turbine. The enhanced braking mode is characterized by operating the generator at a torque setpoint that generates maximum available torque for a given set of operating conditions. Additionally, the torque setpoint is in excess of a nominal torque limit for the generator.

A downhole turbine includes a plurality of fins. The plurality of fins have an exit angle that exerts a tangential force on the fin, which imparts a torque on a hub. The fins have an adjustable exit angle that changes in response to changes in the properties of a drilling fluid. The changing exit angle changes the tangential force, which changes the torque on the hub.

A wind turbine drive system includes a plurality of drive devices, a state quantity detection unit, and a control unit. The plurality of drive devices are provided in a first structure (a nacelle), and a ring gear is provided in a second structure (a tower). Each of the drive devices includes a motor drive portion, a speed reducing portion, and a motor braking portion for braking the motor drive portion. The state quantity detection unit detects a load between a meshing portion of each of the drive devices and the ring gear. Based on the thus detected load for the each of the drive devices, the control unit controls at least one of the motor drive portion and the motor braking portion so as to reduce a degree of variation in the load among the drive devices.

A wind power generation system has a windmill, a lift improvement device, a power generator, a storage, and a controller. The windmill rotates when receiving an airflow. The lift improvement device has a capability of operating and halting, the lift improvement device increases a lift force to a blade of the windmill when operating. The power generator generates power by rotation of the windmill and a torque is generated in a direction suppressing rotation of the windmill. The storage stores a plurality of characteristic maps indicating characteristics of the torques of the power generator in relation to rotation speeds of the power generator. The controller controls a power generation amount of the power generator by switching and using the plurality of characteristic maps of the storage in correspondence with a state of operating or halting of the lift improvement device.

The invention relates to control of a wind turbine to address varying drivetrain loading. This is obtained by determining a modification signal to be set as a control signal. A signal indicative of a speed of the electrical generator a signal indicative of a requested output power are received. The signal indicative of a speed is filtering to isolate frequencies in a selected disturbance frequency band to generate a disturbance signal. The disturbance signal is phase shifted and combined with a requested output power to obtain the modification signal.

A method for operating a wind turbine connected to a power grid in response to one or more grid events occurring in the power grid includes monitoring, via one or more sensors, the power grid (such as a frequency thereof) so as to detect one or more grid events occurring in the power grid. In response to detecting one or more grid events occurring in the power grid, the method includes increasing mechanical inertia of a rotor of the wind turbine during a first time frame after one or more grid events occurs in the power grid. After the first time frame, the method includes providing a required additional power output to the power grid during a subsequent, second time frame so as to stabilize the power grid after one or more grid events occurs in the power grid.

Provided is a method of controlling at least one wind turbine in case of a rotational overspeed situation, the method including: determining a current state related to the wind turbine; providing data related to the current state as input to a turbine model; predicting a load of at least one wind turbine component and power output of the wind turbine using the turbine model provided with the input for plural control strategies; comparing the predicted load and power output for the plural control strategies; and selecting that control strategy among the plural control strategies that satisfies a target criterion including the load and the power output.

The invention provides a method of shutting down a wind turbine, the wind turbine comprising a rotor with a plurality of blades; and a generator system coupled to the rotor. The method comprises: operating the generator system to generate electrical power and apply a load torque to the rotor; controlling the electrical power generated with a power reference signal; determining that a shutdown of the wind turbine is required; in response to the determination that a shutdown of the wind turbine is required, changing the power reference signal so as to increase the electrical power generated thereby slowing the rotor; determining that a speed of the rotor has reduced below a threshold; and in response to the determination that the speed of the rotor has decreased below the threshold, changing a pitch of the blades to further slow the rotor.