Enhancing Fault Ride-Through Capability of DFIG-Based Wind Turbines Using Inductive SFCL With Coordinated Control

Doubly fed induction generators (DFIGs) have difficulties to ride through serious faults just relying on modified controls due to limited power ratings in rotor-side converters. This paper presents a new protection strategy for DFIGs by combining an inductive superconducting fault current limiter (SFCL) with coordinated control. The SFCL topology, system modeling, and transient control are presented. Under normal conditions, the inductive SFCL can act as a filter benefiting the steady-state operation. When faults occur, the simulation results show that the peak values of the stator current, rotor current, dc voltage, and electromagnetic torque oscillation can be effectively suppressed. With transient voltage control, the required positive sequence reactive current can be generated to supply dynamic reactive support. Moreover, proper switching off of the SFCI, and coordinated control can smooth the transient recovery process after a fault.