Application of SFCL to improve the transient voltage stability of grid-connected wind farm with DFIG during grid faults

A novel superconducting fault current limiter (SFCL) based transient voltage stability scheme is presented for use in wind farms driven by doubly-fed induction generator (DFIG) during grid faults. The proposed scheme consists of active and passive self-acting voltage compensators. The active compensator is carried out by allocating the reactive power references between the stator and the grid side converter automatically. The passive compensator utilizes a SFCL to improve the reduced stator voltage, which in turn considerably improves the controller performance of the active voltage compensator. Simulation results verify that both the output reactive power for grid voltage support and the stator voltage level for efficient grid-connection strictly satisfy with the grid code requirements.