Abstract: The short-circuit current characteristics of wind power generation systems represented by doubly-fed induction generators (DFIGs) differ from those of synchronous generators. The inconsistent equivalent impedance of DFIGs before and after faults leads to inaccuracies in short-circuit current calculations for power systems with high wind power penetration. This paper proposes a rapid calculation method and suppression strategy for large-scale grid short-circuit currents under high wind power penetration. By analyzing the dynamic response characteristics of the rotor side of DFIGs, the variation in equivalent impedance before and after faults is quantified, and the system node impedance matrix is modified. The fault current limiter (FCL) is equivalently modeled as a shunt impedance to avoid matrix inversion operations in the node impedance matrix. An iterative impedance unit configuration method is proposed to optimize FCL placement and suppress short-circuit currents. Simulation results demonstrate that the proposed method effectively suppresses short-circuit currents in wind-integrated systems. Compared with existing approaches, the proposed method requires fewer FCLs with smaller capacity while achieving higher computational efficiency.

Key words: doubly-fed induction generators (DFIGs), short-circuit current, fault current limiter, node impedance matrix