Abstract: Provided is a method for controlling, by means of field-oriented closed-loop control, an active rectifier which is electrically connected to a stator of a generator of a wind turbine. The generator has a rotor which is mounted so as to be rotatable about the stator and comprises the steps of determining a mechanical position of the rotor with respect to the stator, predefining DC components of rotor-fixed d and q coordinates for at least one 3-phase stator current, determining an AC component for the q coordinate at least as a function of the mechanical position of the rotor, modulating the determined AC component of the q coordinate onto the predefined DC component of the q coordinate, so that a modulated q coordinate is produced which has a DC component and an AC component, and controlling the active rectifier at least as a function of the modulated q coordinate and preferably as a function of the d coordinate.

Abstract: Provided is a method for controlling a wind power system, that is to say a wind power installation or a wind farm comprising a plurality of installations, for feeding electrical power from wind into an electrical supply grid, and for damping low-frequency oscillations, in particular subsynchronous resonances, in the grid, wherein the grid has a line voltage with a nominal line frequency, wherein a damping control with a closed control circuit is used for damping the low-frequency oscillations, and the damping control for damping the low-frequency oscillations controls a feed-in of electrical power into the grid using a wind system control, the damping control is designed for a controlled system comprising the grid, the wind power system, and the wind system control, or parts thereof, wherein the damping control is designed such that it prevents and/or damps weakly damped modes in the closed control circuit.

Abstract: A method for controlling a multiphase separately excited synchronous generator in a wind turbine is provided. The generator has a stator and an armature having an excitation input, connected to an excitation controller, for inputting an excitation current or an excitation voltage. The stator has a stator output, connected to a rectifier, for delivering stator currents. The rectifier is controllable to control the stator currents by detecting a speed of the armature or rotor, determining a setpoint power to be delivered by the generator or the turbine based on the speed, determining an excitation current or voltage based on the detected speed and determined setpoint power, inputting the excitation current or voltage by excitation controller at the excitation input, determining the stator currents as setpoint stator currents based on the speed and the setpoint power, and controlling the rectifier to set the stator currents to the setpoint stator currents.

Abstract: A method for controlling a wind farm to damp low-frequency electrical oscillations, in particular subsynchronous resonances, in an electrical supply grid having a grid voltage with a nominal grid frequency is provided. The wind farm comprises at least one wind turbine connected to the electrical supply grid.

Abstract: Provided is a method for controlling an active rectifier connected to a stator of a wind power installation using field-oriented control. The generator comprises a stator having an axis of rotation around which the rotor is mounted. The method includes predefining rotor-fixed d and q coordinates for at least one 3-phase stator current of the generator and determining at least one alternating component for the rotor-fixed d and/or q coordinate depending on a detected amplitude and detected phase position of an electrical power oscillation on the generator and taking account of a rotor position representing a mechanical position of the rotor in relation to the stator. The method includes adding the alternating component for the rotor-fixed d and/or q coordinate to the rotor-fixed d and/or q coordinate to form a modified d and/or q coordinate, and controlling the active rectifier at least depending on the modified d and/or q coordinate.

Abstract: Provided is a method for controlling a wind power system, that is to say a wind power installation or a wind farm comprising a plurality of installations, for feeding electrical power from wind into an electrical supply grid, and for damping low-frequency oscillations, in particular subsynchronous resonances, in the grid, wherein the grid has a line voltage with a nominal line frequency, wherein a damping control with a closed control circuit is used for damping the low-frequency oscillations, and the damping control for damping the low-frequency oscillations controls a feed-in of electrical power into the grid using a wind system control, the damping control is designed for a controlled system comprising the grid, the wind power system, and the wind system control, or parts thereof, wherein the damping control is designed such that it prevents and/or damps weakly damped modes in the closed control circuit.

Abstract: A method for feeding electrical power into a three phase electrical power supply network at a network connection point, in particular by means of a wind power installation, using an inverter, comprising the following steps: detecting an electrical network voltage, in particular at the network connection point, determining a virtual generator voltage using a machine model that emulates a behavior of a synchronous machine, preparing the detected network voltage for comparison with the virtual genera-tor voltage, predefining a setpoint current as predefinition for an infeed current as a function of the virtual generator voltage and as a function of the network voltage prepared for comparison, and generating the infeed current depending on the setpoint current and feeding the generated infeed current at the network connection point into the electrical power supply network, wherein preparing the detected network voltage for comparison with the virtual generator voltage comprises transforming the detected network v

Abstract: A method for controlling a wind farm to damp low-frequency electrical oscillations, in particular subsynchronous resonances, in an electrical supply grid having a grid voltage with a nominal grid frequency is provided. The wind farm comprises at least one wind turbine connected to the electrical supply grid.

Abstract: Provided is a method for controlling, by means of field-oriented closed-loop control, an active rectifier which is electrically connected to a stator of a generator of a wind turbine. The generator has a rotor which is mounted so as to be rotatable about the stator and comprises the steps of determining a mechanical position of the rotor with respect to the stator, predefining DC components of rotor-fixed d and q coordinates for at least one 3-phase stator current, determining an AC component for the q coordinate at least as a function of the mechanical position of the rotor, modulating the determined AC component of the q coordinate onto the predefined DC component of the q coordinate, so that a modulated q coordinate is produced which has a DC component and an AC component, and controlling the active rectifier at least as a function of the modulated q coordinate and preferably as a function of the d coordinate.

Abstract: A method for controlling a multiphase separately excited synchronous generator in a wind turbine is provided. The generator has a stator and an armature having an excitation input, connected to an excitation controller, for inputting an excitation current or an excitation voltage. The stator has a stator output, connected to a rectifier, for delivering stator currents. The rectifier is controllable to control the stator currents by detecting a speed of the armature or rotor, determining a setpoint power to be delivered by the generator or the turbine based on the speed, determining an excitation current or voltage based on the detected speed and determined setpoint power, inputting the excitation current or voltage by excitation controller at the excitation input, determining the stator currents as setpoint stator currents based on the speed and the setpoint power, and controlling the rectifier to set the stator currents to the setpoint stator currents.

Abstract: A method for feeding electrical power into a three phase electrical power supply network at a network connection point, in particular by means of a wind power installation, using an inverter, comprising the following steps: detecting an electrical network voltage, in particular at the network connection point, determining a virtual generator voltage using a machine model that emulates a behavior of a synchronous machine, preparing the detected network voltage for comparison with the virtual genera-tor voltage, predefining a setpoint current as predefinition for an infeed current as a function of the virtual generator voltage and as a function of the network voltage prepared for comparison, and generating the infeed current depending on the setpoint current and feeding the generated infeed current at the network connection point into the electrical power supply network, wherein preparing the detected network voltage for comparison with the virtual generator voltage comprises transforming the detected network v