Interruption of fault currents due to symmetrical voltage dips near generating power plants employing doubly-fed induction generators

Variable-speed turbines have gained increasing importance in pumped-storage power plants since they present big advantages compared to the classical topology with a synchronous generator. Within the variable-speed solutions, the one employing a doubly-fed induction generator (DFIG) has become the preferred alternative for large installations since it provides the advantages of variable-speed operation and four-quadrant active and reactive power capabilities using converters rated only a small fraction of the rated power. Faults currents fed by a DFIG differ substantially from the typical current waveform fed by a synchronous generator and can impose very severe stresses for a circuit-breaker to cope with. The question whether a high-voltage circuit-breaker is capable of interrupting fault currents due to symmetrical voltage dips near pumped-storage power plants employing DFIGs is considered in the present work.