Improved Adaptive Filter FLL Control Algorithm for Enhancing Performance of Islanded Microgrid Supplying Dynamic Loads

In this paper, an improved adaptive filter frequency locked loop (IAF-FLL) control technique for VSC is used for a standalone microgrid. This control coordinates all reactive power sources in the system during sudden start of a dynamic IM (Induction Motor) load and provides reactive power to overcome the voltage dip in the system. This system consists of a permanent magnet brushless DC generator (PMBLDCG) for the wind power generation, solar PV (Photovoltaic) array, and pico-hydro turbine-driven synchronous reluctance generator (SyRG) feeding critical loads, which contains nonlinear load and IM loads. A robust IAF-FLL control strategy based on the FLL is used for detecting and adjusting to the prerequisite frequency in transient conditions. This frequency adaptiveness of IAF-FLL is validated through comparative studies done with EAF, SOGI and MSOGI control algorithms. Besides, comparative studies are also done with conventional control algorithms and the simulation results validate its faster convergence rate and reduced steady-state error. This control has added advantage of DC offset and noise removal. Test results validate the system performance in both steady and dynamic conditions.