The present invention relates to a method for stabilizing a rotor of a wind turbine during a time period following an abnormal grid event, the method comprising the steps of detecting an occurrence of the abnormal grid event, reducing an allowable rotor thrust from a first thrust limit to a second thrust limit, detecting that the abnormal grid event has ended, and maintaining the second thrust limit a selected time period after the abnormal grid event has ended. The present invention further relates to a wind turbine controller and a computer program product for performing this method.

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 rotary machine includes a rotor rotatable about a rotation axis and a stator mechanically divided into stator segments, each covering a respective section in relation to the rotation axis. Coils of one individual multi-phase rotary system are respectively arranged in the stator segments, each having terminals which connect phase lines of an individual multi-phase rotary system and are connected to the coils. A converter unit includes multiple subunits operated independently of one another, each forming an individual multi-phase rotary system. The number of phases of the subunits corresponds to the number of stator segments. The terminals of the stator segments are each connected to a subunit. The stator segments form groups of directly successive stator segments when viewed about the rotation axis. The terminals of the stator segments are connected to the same sub-unit within each group, but connected to different sub-units from group to group of stator segments.

Systems, methods, and non-transitory computer readable media including instructions for a dual-channel fluid turbine controller. A dual-channel fluid turbine controller includes at least one processor configured to: receive, via an AC channel coupled to an AC output of a fluid turbine, first signals indicating fluctuations in power generated by the fluid turbine operating beneath a grid power supply threshold; access an MPPT protocol; determine a correspondence between the first signals and a portion of the MPPT protocol; apply the portion of the MPPT protocol to a generator of the fluid turbine to generate greater power than would be generated in an absence of the MPPT protocol, wherein the generated power is stored as energy in a capacitor associated with the generator; receive, via a DC channel, second signals indicating a level of energy stored in the capacitor; and use the second signals to determine when to release the stored energy.

A method of monitoring a first winding set and at least one second winding set of a stator of a generator during operation is provided. The method includes: obtaining a first strength of a second harmonic of a first power produced from the first winding set; obtaining a second strength of a second harmonic of a second power produced from the second winding set; diagnosing the first winding set and/or the second winding set based on a second harmonic power difference between the first strength and the second strength.

Provided is a control module of a converter, in particular a power converter of a wind power installation, which is configured to control the converter in such a way that the converter emulates a behavior of a synchronous machine, comprising an, in particular internal, control loop which has an, in particular adjustable, virtual admittance by means of which the converter is controlled in order to emulate the behavior of the synchronous machine.

A method for providing frequency response for a plant coupled to an electric power grid, the plant having an intermittent energy source, comprising: measuring frequency of the power output from the plant and determining a first difference between the measured frequency and a frequency reference; measuring power output from the plant and storing the measured power output as a stored value; while the first difference is within a deadband, determining a second difference as a difference between a power reference and the measured power output; while the first difference indicates over-frequency, determining the second difference as a difference between the stored value and the measured power output; while the first difference indicates under-frequency, setting the second difference equal to the power reference; generating an error by limiting a sum of the first and second differences between error limits; generating a control signal; and, applying the control signal to the source.

The present disclosure relates to a wind turbine comprising a wind turbine rotor with a plurality of blades supported on a support structure, a generator operatively coupled to the wind turbine rotor for generating electrical power, a power electronic converter for converting electrical power generated by the generator to a converted AC power of predetermined frequency and voltage, and a main wind turbine transformer having a low voltage side and a high voltage side for transforming the converted AC power to a higher voltage. One or more electric filters are connected to the high voltage side of the main transformer, wherein the electric filters are arranged in the support structure. The present disclosure also relates to wind farms, and particularly offshore wind farms, and to methods for operating wind farms.

A method for controlling an inverter-based resource (IBR) connected to a power grid during a grid event includes operating the IBR based on a first virtual impedance reference prior to the grid event, the first virtual impedance reference being used for determining a first virtual impedance of the IBR defining a first virtual reactance and a first virtual resistance. The method also includes receiving an indication of a start of the grid event that causes a change in the first virtual impedance reference to a second virtual impedance reference. Immediately after the change in the first virtual impedance reference, the method includes activating a soft activation module for outputting a second virtual impedance defining a second virtual reactance and a second virtual resistance that maintains a magnitude of the second virtual impedance at or above a magnitude of the second virtual impedance reference so as to reduce current in the inverter-based resource. At a certain time period after activating the soft activation module, the method includes transitioning the second virtual reactance and the second virtual resistance to a virtual reactance and a virtual resistance defined by the change.

The wind power generation device includes a blade, a power distribution unit, a first generator, a second generator, a clutch unit, and a control unit. The control unit controls connection and disconnection of the clutch unit such that the clutch unit is disconnected when the wind speed input to the blade is smaller than a predetermined first wind speed value and the clutch unit is connected when the wind speed input to the blade is larger than a predetermined second wind speed value.