A method for calibrating a wind direction measurement for a wind turbine is provided. The method including: measuring plural samples of a relative wind direction representing a difference angle between a real wind direction and an orientation of a measurement equipment, in particular a direction orthogonal to a rotor blade plane, to obtain plural measured relative wind directions; deriving a measured relative wind direction change based on the measured relative wind directions; measuring plural samples of a performance parameter indicating a performance of the wind turbine; deriving a performance change based on the plural samples of the performance parameter; determining a correlation value between the measured relative wind direction change and the performance change; measuring further plural samples of the relative wind direction; and correcting the further measured relative wind directions based on the correlation value, to obtain corrected further measured relative wind directions.

A method for calibrating a wind direction measurement for a wind turbine is provided. The method including: measuring plural samples of a relative wind direction representing a difference angle between a real wind direction and an orientation of a measurement equipment, in particular a direction orthogonal to a rotor blade plane, to obtain plural measured relative wind directions; deriving a measured relative wind direction change based on the measured relative wind directions; measuring plural samples of a performance parameter indicating a performance of the wind turbine; deriving a performance change based on the plural samples of the performance parameter; determining a correlation value between the measured relative wind direction change and the performance change; measuring further plural samples of the relative wind direction; and correcting the further measured relative wind directions based on the correlation value, to obtain corrected further measured relative wind directions.

A method of operating at least one wind turbine including: receiving a first signal which is indicative of a level of a remuneration for electrical energy, which is fed currently and/or in the future into a grid to which the wind turbine is connected, producing a control signal dependent on the first signal, and controlling the wind turbine with the control signal for generating power of the wind turbine, that is dependent on the control signal. A wind turbine and a central control for carrying out such a method and a system comprising a central control and a plurality of wind turbines.

Provided is a method of controlling a multi-channel multi-phase electrical machine including a plurality of channels each with a set of phase windings connected to a converter, which method includes the steps of operating the converters to electrically phase-shift the channels; computing harmonic injection currents for a dominant harmonic on the basis of electrical quantities in a rotating reference frame; determining harmonic voltage references for the dominant harmonic on the basis of the harmonic injection currents; and regulating the AC output voltages of the channels according to the fundamental voltage references and the harmonic voltage references. Also provided is a control arrangement of a multi-channel multi-phase electrical machine; a wind turbine; and a computer program product.

Provided is a method of controlling a multi-channel multi-phase electrical machine including a plurality of channels each with a set of phase windings connected to a converter, which method includes the steps of operating the converters to electrically phase-shift the channels; computing harmonic injection currents for a dominant harmonic on the basis of electrical quantities in a rotating reference frame; determining harmonic voltage references for the dominant harmonic on the basis of the harmonic injection currents; and regulating the AC output voltages of the channels according to the fundamental voltage references and the harmonic voltage references. Also provided is a control arrangement of a multi-channel multi-phase electrical machine; a wind turbine; and a computer program product.

A first aspect of the invention provides a method of testing a yaw system (200) of a wind turbine, the wind turbine comprising a rotor; the yaw system (200) comprising a yaw gear (202) coupled to the rotor so that rotation of the yaw gear (202) causes yaw rotation of the rotor, and first and second sub-systems (204a, 204b), the first sub-system (204a) comprising a first pinion gear (206a) and a first drive motor (208a) coupled to the yaw gear (202) by the first pinion gear (206a), the second sub-system (204b) comprising a second pinion gear (206b) and a second drive motor (208b) coupled to the yaw gear (202) by the second pinion gear (206b). The method comprises the steps of: testing the first sub-system (204a) by: applying a first yaw moment to the yaw gear (202) with the second drive motor (208b) via the second pinion gear (206b), reacting the first yaw moment with the first pinion gear (206a), monitoring a yaw motion parameter indicative of rotation of the yaw gear (202), and determining a condition of the first sub-system (204a) based on the monitored yaw motion parameter.

A system refers to actual weather data made publicly available by a first institution, and creates a model that uses a value of a weather element for each section as an input and uses a value of a renewable energy power generation amount of the area as an output based on the actual value of the weather element calculated for each section, and the actual value of the renewable energy power generation amount of the area. The system refers to weather prediction data made publicly available by the second institution, and calculates an actual value of the weather element regarding each of the plurality of sections including the area based on a prediction value of the weather element for each segment in the corresponding section, and calculates a prediction value of the renewable energy power generation amount based on the prediction value of the weather element for each section.

The invention provides a method for controlling a wind power plant that receive operating command requests via a distributed system comprising a plurality of subsystems each associated with a respective party capable of issuing requests. One subsystem generates a request to operate the wind power plant in accordance with a defined operating command desired by the associated party. The request is broadcast to each of the other subsystems to approve or disapprove the requests. Each subsystem broadcasts to the other subsystems if it approves the request, and each subsystem maintains a database including a record of which subsystems have approved the request. The wind power plant is controlled based on which subsystems have approved the request, where at least one subsystem other than the subsystem that generates the request needs to have approved the request before the plant implements the defined operating command.

The invention provides a method for controlling a wind power plant that receive operating command requests via a distributed system comprising a plurality of subsystems each associated with a respective party capable of issuing requests. One subsystem generates a request to operate the wind power plant in accordance with a defined operating command desired by the associated party. The request is broadcast to each of the other subsystems to approve or disapprove the requests. Each subsystem broadcasts to the other subsystems if it approves the request, and each subsystem maintains a database including a record of which subsystems have approved the request. The wind power plant is controlled based on which subsystems have approved the request, where at least one subsystem other than the subsystem that generates the request needs to have approved the request before the plant implements the defined operating command.

Disclosed are techniques for recovering power from remote vehicles near a landing surface. Air turbulence from a remote vehicle near a landing surface is detected and measured. When the air turbulence exceeds a threshold, a subset of landing surface components corresponding to sections of the landing surface with attached wind power generators are determined for wind power generation from the detected air turbulence. The wind power generators of the subset of landing surface components are exposed from their protective coverings, and the subset of landing surface components are reoriented towards the source of the air turbulence, tracking the remote vehicle generating the air turbulence. Power generated by the wind power generators can be stored and used to recharge remote vehicles that land at the landing surface.