Suppressing output power fluctuation and improving FRT Capability of DFIG‐based wind energy conversion system with SMES and dual‐mode protection scheme

As the grid codes of wind turbines note, doubly fed induction generator (DFIG)-based energy conversion system (WECS) should maintain uninterrupted operation during certain voltage faults. To meet codes, a novel configuration DFIG-based WECS is proposed in which superconducting magnetic storage (SMES) and series transformer are incorporated. The control strategies redesigned to smooth output power fluctuations ride through different levels grid-side converter (GSC) controlled caused by random speeds under normal conditions. GSC protection circuit switch into compensation mode fully compensate stator swells slight sags. While severe sags, operates current limiting mode, significantly limits rotor fault overcurrent, improves supresses electromagnetic torque. faults applied, simulation results demonstrate that presented scheme can effectively strengthen ride-through capability (FRT) WECS.