A new resonant fault current limiter for improved wind turbine transient stability

Abstract

This paper proposes a new resonance-type FCL, which is designed specifically for DFIG-based wind turbines. The proposed topology overcomes the well-documented drawbacks associated with conventional resonance-based FCLs while preserving the advantages of this topology. The proposed circuit limits the fault current for the entire fault period independently of the reactor's charging state and significantly reduces the wind turbine's torque oscillations during a fault. The proposed FCL is simulated as part of a power system that includes a wind turbine, synchronous generator, and two step-up transformers. The results show that during a three-phase to-ground fault, the proposed FCL significantly improves the system's stability, and leads to improved fault current, voltage, active power, reactive power, and torque transients.