A method is provided for determining a power production capacity of at least one wind turbine connected to a power grid. The method includes receiving, e.g. from a power grid control center, a power production forecast for the at least one wind turbine, and then monitoring an actual grid frequency of the power grid. Based on the actual grid frequency and a nominal grid frequency, a frequency support power reserve is determined. The power production capacity is then determined in dependence of the determined frequency support power reserve and the power production forecast

A method is provided for controlling the operation of a wind turbine, the wind turbine including a generator, a converter, a converter control unit, a wind turbine controller and a connection device to an external electrical power grid, wherein electrical power generated by the generator is input into the power grid via the converter, wherein the wind turbine controller is configured to determine a fault condition according to a fault condition signal and to active a safe operating mode in response to the fault condition signal indicating a fault condition, wherein the fault condition signal is determined by evaluating changes in an available output power signal generated by the converter control unit, the available output power signal describing the active output power available from the converter.

A system and method for simultaneously coordinating a wake control system and a noise control system of a wind farm having a plurality of wind turbines is disclosed. The method includes determining, via a farm controller, one or more wake control set points for the wake control system. Further, the method includes determining, via the farm controller, one or more noise control set points for the noise control system. The method also includes selecting, via the farm controller, between the wake control set points and the noise control set points for each of the plurality of wind turbines. Thus, the method also includes sending, via the farm controller, the selected control set points to local controllers of the plurality of wind turbines and operating the wind farm based on the selected control set points.

A method for providing grid-forming control of a double-fed wind turbine generator connected to an electrical grid includes receiving at least one control signal associated with a desired total power output or a total current output of the double-fed wind turbine generator. The method also includes determining a contribution of at least one of power or current from the line-side converter to the desired total power output or to the total current output of the double-fed wind turbine generator, respectively. The method also includes determining a control command for a stator of the double-fed wind turbine generator based on the contribution of at least one of the power or the current from the line-side converter and the at least one control signal. Further, the method includes using the control command to regulate at least one of power or current in the stator of the double-fed wind-turbine generator.

Aspects of the present invention relate to a method of voltage control for at least one wind turbine generator configured to absorb and supply reactive power on demand, the method comprises: receiving a dispatch signal from a power plant controller indicating a reactive power set point; determining a terminal voltage level of the at least one wind turbine generator; generating a reactive power correction value based on a deviation of the terminal voltage level from a voltage set point; adjusting the reactive power set point by the reactive power correction value; and controlling the at least one wind turbine generator according to the adjusted reactive power set point.

A method for operating a wind farm having a string (S1-S3) of wind turbines (100-100d) which are electrically connectable with each other and a grid (510, 550) via power connections (Cab-Cd) is disclosed. Each wind turbine includes a rotor (106) with rotor blades (108), and a power conversion system (118, 210, 238) mechanically connected with the rotor (106). The method includes disconnecting the string (S1-S3) from the grid (510, 550), and identifying a primary wind turbine (100a, 100c) of the disconnected string (S1-S3) which is electrically connectable with at least one secondary wind turbine (100b-10d) of the disconnected string (S1-S3). The power conversion system (118, 210, 238) of the primary wind turbine (100a, 100c) includes a reactive power capability (RPC) that at least matches a reactive power (RP) of a cluster (C1, C11, C12) to be formed by electrically connecting the primary wind turbine (100a, 100c) with the at least one secondary wind turbine (100b-100d) of the disconnected string (S1-S3).

A method for operating a wind farm having a string (S1-S3) of wind turbines (100-100c) which are electrically connectable with each other and a grid (510, 550) is disclosed. Each wind turbine includes a rotor (106) with rotor blades (108), a power conversion system (118, 210, 238) mechanically connected with the rotor (106), and at least one auxiliary subsystem (105, 109). The method includes operating the wind turbines of the string in an island operating mode in which the wind turbines are not connected with the grid, and the respective at least one auxiliary subsystem is supplied with electric power generated by the power conversion system of the respective wind turbine; detecting that the rotor of one of the wind turbines is exposed to a wind condition at which at least one of the rotor blades is at risk of stalling at the currently generated electric output power; and increasing the electric power generated by the power conversion system of the one of the wind turbines by an electric power amount which is sufficient for suppling the at least one auxiliary subsystem of at least one of the other wind turbines of the string.

In various embodiments of the present disclosure, there is provided a method of controlling active power generation of a wind power plant coupled to a power grid, the wind power plant including a power plant controller for controlling a plurality of wind turbine generators. In an embodiment, the method includes monitoring an operational status of a plant compensation equipment and adjusting a plant reactive power capability when the operational status of the plant compensation equipment indicates a fault in the plant compensation equipment. According to an embodiment, the method includes controlling the wind power plant to curtail the active power generated by the wind power plant by a curtailment amount determined based on the adjusted plant reactive power cap ability. A corresponding wind power plant is further provided.

A system and method are provided for controlling low-speed operations of a wind turbine electrically coupled to an electrical grid. The wind turbine includes a generator and a power converter. The generator includes a generator rotor and a generator stator. An operating parameter of the generator rotor is indicative of a low-speed operation of the generator. Accordingly, the crossing of a first threshold by the operating parameter is detected. In response, at least a portion of a required reactive power generation is developed via the generator rotor. The portion is then delivered to the electrical grid via the grid side of the power converter.

This disclosure is directed to a method for operating a wind farm having a plurality of wind turbines and to a control system for a wind farm. The wind farm is connected to an electrical grid. The wind turbines are operated to supply electrical power to the electrical grid in accordance with at least one setpoint value for a power related electrical variable. In the event that an available reactive power of the wind farm is smaller than a setpoint for a reactive power to be supplied by the wind farm, a required increase of reactive power is determined for each wind turbine of the wind farm.