Nordex Energy Gmbh

Nordex Energy Se & Co. Kg

Nordex Christian

Ingenieurbuero Hoffmann Gmbh

Metabowerke Gmbh

Ingenieurbüro Hoffmann Gmbh

Christian Wessels

Klaus Raasch

Simon De Rijcke

Niels Hamann

Nils Hoffmann

Bernhard Niemann

Heinz Jansen

Andreas Müller

Antonius Imholt

Christian Moorkamp

Werner Wittrock

Thomas Meelker

This disclosure is directed to a method for operating a wind turbine which includes a speed-variable drive system. The system includes an electrical machine and a pulsewidth modulation-controlled converter. The speed-variable drive system is connected to an electrical grid. In the event of a transient grid fault, a frequency of the pulsewidth modulation is determined in response to a current in an electrical circuit connected to the converter.

Method for operating a wind turbine and wind turbine

A method is provided for controlling a wind turbine that has a generator that is controlled via a converter in a boost operation, in which an electrical power that is fed into an electrical transmission network is increased via a generative deceleration of the generator. The method comprises using a control to determining a set point value for a generator torque depending on an actual value of a rotational speed. The determined set point value for the generator torque is applied to a generator via a limiter with a predefinable upper and lower limit. Determining the set point value for the generator torque in boost operation that leads to an increased fed-in electrical power in response to a boost signal; and limiting a temporal change of the set point value for the generator torque in a recovery operation in response to a recovery signal.

Method for controlling a wind turbine

A method for controlling a wind turbine comprising inputting an actual value of rotational speed and a rotational speed setpoint into a control and outputting a set point value for a generator torque from the control. Inputting the set point value for the generator torque into a limiter with a predefinable upper and lower limit and outputting a limited torque value that is fed into a converter control. Increasing the actual value of the fed-in electrical power by an additional amount of power in response to a boost signal, wherein the fed-in electrical power and the additional amount of power are combined into an aggregated power setpoint value. Determining the set point value for the generator torque from the aggregated power setpoint value and applying the set point value for the generator torque in the boost operation to the limiter both as the upper limit and as the lower limit.

The invention is directed to a method for controlling a wind turbine connected to a three-phase electrical supply grid during an asymmetrical grid fault. The method is configured for wind turbines with a doubly-fed induction generator. The reactive current to be fed into the electrical supply grid in the negative phase-sequence system is generated by the line-side and the rotor-side converter in a coordinated manner and depends on the line voltage. The reactive current to be fed into the electrical supply grid is distributed among the rotor-side and line-side converters. As a result, even in the case of severely asymmetrical grid faults, the reactive current to be fed into the electrical supply grid can be provided and excessive loading of the rotor-side converter can be prevented using simple means. The invention is also directed to a wind turbine for performing the above method.

Method for controlling a wind turbine during an asymmetrical grid fault and a wind turbine

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Hamburg, Germany

Christian Wessels