Synchronization Stability Constrained SFCL-Based Fault Ride-Through Strategy for PMSG

Superconducting fault current limiter (SFCL) can be applied to improve the fault ride-through (FRT) capability of permanent magnet synchronous generators (PMSG). However, the insertion of SFCL may increase the risk of losing equilibrium point during severe grid faults, which can lead to synchronization instability of PMSG. To this end, an improved SFCL-based FRT strategy considering the transient synchronization stability issue is proposed in this paper. The effect of resistive type SFCL on FRT performance improvement and the mechanism of loss of synchronization (LoS) between the PMSG-based wind farm and power grid are quantitatively analyzed, and a criterion for LoS is derived for designing the parameter of SFCL. Then, an FRT strategy that coordinates SFCL and grid side converter (GSC) of PMSG is proposed. Dynamic simulations in PSCAD/EMTDC verify the validity of the conducted theoretical analysis and the effectiveness of the proposed coordinated strategy in enhancing FRT performance while ensuring system synchronization stability during various grid faults.