Method for operating a converter, in particular of a wind power installation

An apparatus comprising:

• an inverter having an input coupled to a wind power installation, and an output coupled to a three-phase electrical power supply grid;
• a controller coupled to the inverter and configured to cause the inverter to inject electrical energy into the three-phase electrical power supply grid, wherein the controller is configured to:
• operate the inverter in a first operating mode for generating an output current, wherein the inverter in the first operating mode applies an output current to the three-phase electrical power supply grid such that the inverter controls the voltage of the three-phase electrical power supply grid by applying the output current having a particular amplitude, a particular phase angle, and a particular frequency to the three-phase electrical power supply grid;
• detect a grid fault on the three-phase electrical power supply grid during the first operating mode;
• in response to detecting the grid fault, continue to operate in the first operating mode and limit the output current of the inverter by current limitation, wherein limiting the output current comprises generating the output current dynamically by a reference system;
• and
• set a voltage reference system to a detected output clamping voltage.