Modern Control Techniques for Enhancement of Voltage Sag in a MMC Coupled DFIG Based Wind Systems

Abstract

Fractional Order Sliding Mode Controller (FOSMC) is a hybrid one and has been integrated to escalate low voltage ride through (LVRT) during faults in a modular multilevel converter (MMC) based doubly fed induction generator (DFIG) connected wind energy conversion system (WECS). Voltage sag at grid directly affects stator of DFIG, due to its immediate connection. The machine’s rotor is joined to power electronic converters i.e. a rectifier (MSC) and an inverter (GSC) via a DC link. A Fractional Order Sliding Mode controller is used at Grid Side Converter to mitigate fault current and ameliorate parameters at stator, rotor terminals. This paper infers that proposed Fractional Order Super Twisting Algorithm (FOSTA) deployed Sliding Mode Controller (FOSMC) is the exceptional in dealing with symmetrical and asymmetrical faults by refining power quality parameters, LVRT problem. The fault ride capability with FOSMC is good compared to FOPI and SMC controllers.