Calculation method of short-circuit currents in DFIG-based wind farms considering voltage distribution

摘要

When the short circuit occurs in a wind farm, the generator terminal voltage drops of doubly fed induction generators are different and have a great impact on the short-circuit currents contribution of the doubly fed induction generators. Firstly, a practical calculation model for the short-circuit currents and a correction method of the topology matrix of the wind farm under a symmetrical short circuit are presented in this paper. And then, a calculation method of short-circuit currents in DFIG-based wind farms considering voltage distribution is obtained. Finally, the accuracy of this method is verified by time domain simulation. Moreover, the values obtained in this way are compared to the values obtained from national standard (the same as IEC60909). The results show that the proposed method is at least 25% lower than the IEC60909 standard.