Patent ID: 8294430

Claim:
A method for operating a double-fed asynchronous generator comprising a stator ( 1 a ) and a slipring rotor ( 1 b ); the method includes the following steps: Connect the stator ( 1 a ) to a power supply network ( 3 ), mechanically connect the rotor ( 1 b ) to a drive ( 11 , 12 ), electrically couple the rotor ( 1 b ) via a machine-side converter and a power supply-side converter ( 5 , 6 ) to the network ( 3 ), monitor the network ( 3 ) to detect short-circuit current, supply a field-oriented current to the rotor ( 1 b ) at a frequency that substantially corresponds to the difference between the electrical network frequency and a mechanical frequency derived from the drive RPM, and regulate the machine-side rotor current, at the least, by determining the actual values (iRMist) of the machine-side rotor current (iRM) and adjusting them to setpoint values that are selected depending on desired operating conditions, wherein, if short circuits are detected in the network ( 3 ), the actual value (iRMist) of the machine-side rotor current (iRM) present at that time is detected, retained (frozen), and used in place of the selected setpoint values to regulate the machine-side rotor current, and therefore the stator ( 1 a ) delivers short-circuit current to the network ( 3 ).