It is provided a wind turbine and methods of operating a wind turbine as described herein.

An electrical power generating assembly for a wind turbine. The electrical power generating assembly comprises a gearbox comprising a gearbox output shaft, a generator comprising a rotor that is coupled to the gearbox output shaft; and a current measuring module located between the gearbox and the generator. The current measuring module comprises: an electrical pickup mounted to the electrical power generating assembly, wherein the electrical pickup includes an electrical contact that engages with a slip ring associated with the rotor. The current measuring module further comprises: a first current measuring device mounted with respect to the electrical pickup to detect current flowing at least through the electrical pickup; and a second current measuring device mounted with respect to the electrical pickup to detect current flowing through at least a component associated with the gearbox output shaft.

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.

System and methods for optimizing operation of a wind turbine are disclosed. In one aspect, the method also includes determining, via a converter controller of a power converter, a tap position of a tap changer configured between the power grid and a primary winding of a transformer. Another step includes calculating, via the converter controller, a primary voltage of the primary winding as a function of the tap position. The method also includes implementing, via the converter controller, a control action if the primary voltage or a measured secondary voltage of a secondary winding of the transformer is outside of a predetermined voltage range.

Methods and Apparatuses for rotational speed avoidance control of a wind turbine, and the wind turbine are provided. An exemplary method includes: identifying whether a wind turbine operates repeatedly traversing a rotational speed avoidance range, based on statistical information about a rotational speed of a generator being in the rotational speed avoidance range; and adjusting a parameter of a pitch control system and/or a parameter of an electromagnetic torque control of the wind turbine based on the statistical information about the rotational speed being in the rotational speed avoidance range, in response to determining that the wind turbine operates repeatedly traversing the rotational speed avoidance range.

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 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 method and system of subsynchronous oscillations and interactions damping integrated in in a rotor converter based on an adaptive state feedback controller with two spinning vectors, and a Kalman filter whose parameters are optimized by minimizing maximum sensitivity under a constraint of positive damping for a plurality of sensible scenarios is provided. The damping signal generated by the damping module is applied either to a power proportional integer controller or to a current proportional integer controller.

A method and a control system using the same for coordinating control of a plurality of wind turbines of a wind farm during a fault in a utility grid to which power is to be delivered via at least one cable of the wind farm. The method includes: opening each of the electrical connections; selecting at least one wind turbine of the plurality of wind turbines according to a criteria where a sum of value for active power supply that is available from the selected at least one generator is equal or above a sum of values for active power consumption that is consumable by the energy storage system of the selected at least one wind turbine, the auxiliary equipment of the selected at least one wind turbine and the substation level auxiliary equipment; activating the selected wind turbine; for the selected wind turbine: electrically connecting the power input of its converter to the power output of its generator, electrically connecting the power output of its converter to the power input of its auxiliary equipment, the power input of its energy storage system and the corresponding cable, and electrically connecting the power input of a substation level auxiliary equipment to the cable which is electrically connected to the selected wind turbine; the activated wind turbine acting as active power supply for the substation level auxiliary equipment. The method and the control system using the same provide an effective and economic way of using the power generated by the wind turbine generator for powering the auxiliary equipment of the wind turbine, charging the energy storage system of the wind turbine and powering the substation level auxiliary equipment, during the wind farm operates in an islanding mode.

Provided is a control unit for a converter, in particular of a wind power installation and/or of a wind farm, comprising: an input for receiving a detected voltage and/or a detected current, an input for receiving a voltage set point and/or a current set point, an input for receiving a correction value and a feedback control system which is set up, depending on the detected voltage and/or the detected current and the voltage set point and/or the current set point and the correction value, to produce a reactive power set point for a modulated, preferably amplitude-modulated reactive and/or active power of the converter.