Fault Ride-Through Capability Improvement of DFIG-Based Wind Turbine by Employing a Voltage-Compensation-Type Active SFCL

Based on the considerations in creating a smart grid roadmap, an integrated application of renewable energy sources and superconducting power devices may bring more positive effects. This paper suggests a voltage-compensation-type active superconducting fault current limiter (SFCL) to enhance the fault ride-through capability of doubly fed induction generator (DFIG) for wind power generation. Since the active SFCL has higher controllability and flexibility than a common resistive- or inductive-type SFCL, its application may give better results. Related theory derivation, cost evaluation, and simulation analysis are conducted, and a comparison between the active SFCL and an inductive SFCL is performed. From the results, the active SFCL can limit the faulty currents flowing through the DFIG´s stator and rotor windings and compensate the generator terminal voltage. The inductive SFCL may not evacuate the surplus active power during the grid fault; however, the active SFCL can smooth the DFIG´s power fluctuation, and the stability of the wind power system can be well strengthened.