Low-voltage ride-through capability enhancement of DFIG-based wind turbine with a resistive-type SFCL connected in series with rotor winding

To satisfy with the low-voltage ride-through (LVRT) requirements from both the grid side and doubly-fed induction generator (DFIG) based wind turbine (WT) itself simultaneously, this paper presents a novel LVRT scheme by using a resistive-type superconducting fault current limiter (SFCL) connected in series with the DFIG rotor winding. The peak fault rotor current characteristics are obtained and further utilized to optimize the SFCL resistance. With the optimized SFCL resistance and operational conditions from the DFIG, system design and circuit modeling of the SFCL are further discussed. Simulation results obtained show that the proposed SFCL-based LVRT scheme is favored to limit the rotor inrush currents and to protect the RSC and gearbox whenever the grid fault occurs. The terminal voltage of the DFIG is also improved with a certain amount of reactive power supplied for the efficient connection to the grid.