A method for operating an asynchronous doubly-fed wind turbine generator connected to a power grid in a grid-forming mode to emulate a virtual synchronous machine. The doubly-fed wind turbine generator includes a line-side converter coupled to a rotor-side converter via a direct current (DC) link. The method includes receiving, via a controller, at least one reference command from an external controller. The method also includes controlling rotor flux of the doubly-fed wind turbine generator using the at least one reference command. Further, the method includes providing power droop control for the doubly-fed wind turbine generator through at least one of rotor-side reference frame rotation and d-axis flux control.

A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects an oscillation in the power output of the wind turbine during a recovery from a transient event. In response to detecting the oscillation, a portion of the power output during a peak phase of the oscillation is stored in an energy storage device. A portion of the stored power is then discharged during a valley phase of the oscillation in order to reduce an amplitude of the oscillation of the power output that is delivered to the power grid.

A detuner system for a wind turbine includes a drive train component having a natural frequency. The drive train component is configured to rotate about an axis of rotation at a range of different speeds. The detuner system includes a controller for selectively interacting with the drive train component and cause a step change in the natural frequency of the drive train component at a first threshold of the rotational speed range, and cause a step change in the natural frequency of the drive train component at a second threshold of the rotational speed range different to the first threshold.

A method for wind turbine tower damping is disclosed, as well as an associated controller and wind turbine. The method comprises determining, using one or more sensor signals, dynamic state information for a tower of a wind turbine during power production, wherein the dynamic state information comprises a tower frequency. The method further comprises determining at least one control loop gain value using the tower frequency, and generating, using the at least one control loop gain value, one or more control signals for controlling a rotational speed of a rotor of the wind turbine.

A method for controlling an inclination of a floating wind turbine platform to optimize power production, or to reduce loads on the turbine, tower, and platform, or both, includes receiving data associated with the inclination of the floating wind turbine platform and wind speed and direction data. An angle of difference between the turbine blade plane and the wind direction is determined, where the angle of difference has a vertical component. A platform ballast system is then caused to distribute ballast to reduce the vertical component to a target angle chosen to optimize power production, or reduce turbine, tower, and platform loads, or both.

A method for detecting a status of a rotor blade for a wind turbine, the rotor blade including at least an aerodynamic device for influencing the airflow, the aerodynamic device being movable between a first and a second configuration, the method including the steps of: measuring an output signal measured by at least one sensor installed on the wind turbine, moving the aerodynamic device between the first configuration and the second configuration, measuring a change in the induced output signal, post-processing the measured output signal, wherein the post-processing is performed in the frequency domain and includes: deriving a frequency spectrum 1, calculating an upper spectrum interval of the frequency spectrum above a frequency threshold value, comparing the upper spectrum interval with a reference frequency spectrum deriving a status of the rotor blade based on the step of comparing.

The present disclosure is directed to a method for responding to a friction coefficient signal of a pitch bearing of a pitch drive mechanism of a wind turbine and/or for controlling the pitch drive mechanism(s) and/or a bank of ultracapacitors. The method and system include: accessing high-frequency measurement data of the at least one pitch bearing; estimating, via a torque balance model implemented by a controller, a frictional torque of the at least one pitch bearing based, at least in part, on the high-frequency measurement data; estimating, via the controller, a friction coefficient signal of the at least one pitch bearing based, at least in part, on the frictional torque; comparing the friction coefficient signal with a friction threshold; determining whether the friction coefficient signal deviates from the friction threshold based, at least in part, on the comparison; and, if so, acting.

A wave power generation apparatus is disclosed. A wave power generation apparatus according to one embodiment can comprise: a floating body floating on the surface of the sea; a power transmission part, which is connected to the floating body so as to receive power generated according to the movement of the floating body, and moors the floating body on the surface of the sea; and a mooring angle adjustment module for adjusting the mooring angle of the floating body for the power transmission part according to the state of the waves acting on the floating body.

A dynamic adaptive mooring system for wave energy converters (WEC) is disclosed that has a mooring configuration that has a set of fixed mooring lines, and a set of movable mooring lines. When an incoming wave train interacts with the fixed WECs, a set of wave interference points that have higher wave amplitudes than the incoming wave train are formed downstream of the fixed WECs. The movable WECs are then positioned at the interface points to optimize wave energy transfer.

A method for controlling an inclination of a floating wind turbine platform to optimize power production, or to reduce loads on the turbine, tower, and platform, or both, includes receiving data associated with the inclination of the floating wind turbine platform and wind speed and direction data. An angle of difference between the turbine blade plane and the wind direction is determined, where the angle of difference has a vertical component. A platform ballast system is then caused to distribute ballast to reduce the vertical component to a target angle chosen to optimize power production, or reduce turbine, tower, and platform loads, or both.