Improved-GWO designed FO based type-II fuzzy controller for frequency awareness of an AC microgrid under plug in electric vehicle

Abstract

The paper proposes to use an improved Grey Wolf Optimization (GWO) optimized Fractional Order (FO) based type-II fuzzy controller for frequency regulation of an AC microgrid in presence of plug-in electric vehicles. The AC microgrid comprises various renewable-based energy sources such as wind turbine generator (WTG), photovoltaic cell (PV), microturbine (MT), aqua electrolyzer based fuel cell (FC) and diesel engine generator (DEG) along with various storage devices (ESD) like battery energy storage (BES), flywheel energy storage (FES) and electric vehicles (EV). The uncertain nature of solar, wind technologies and load demand makes the system more complicated and introduces the frequency oscillations in the system. It is highly needed to establish power balance among generation by designing an appropriate controller for frequency regulation. This paper proposes a robust fractional order type-II fuzzy PID (FO-T2-FPID) where the parameters of the FO-T2-FPID controllers are optimized by suggesting an improved GWO (I-GWO) algorithm. To demonstrate the capability of proposed I-GWO algorithm few comparative analyses have been performed over particle swarm optimization (PSO) and grey wolf optimization (GWO) algorithm. It is also observed that for the same FO-T2-FPID controller structure, the percentage improvement in the objective function (ITAE) under load uncertainty by I-GWO compared to GWO and PSO are 29.74% and 65.94% respectively. Finally, it is conferred that proposed I-GWO optimized FO-T2-FPID controller significantly improves microgrid dynamic performance under various operational conditions.