Frequency dynamics improvement in microgrids using fuzzy logic controller-based virtual inertia emulator

Abstract Inverter Based Power Generation Systems (IBPGS) integrated with distributed generators have low inertia and need sophisticated control systems for frequency regulation. It is essential to maintain frequency deviations within permissible ranges according to country standards during disturbances in a power system. To achieve this in low-inertia IBPGS, the emulation of Virtual Inertia (VI) is an effective solution. Because of the meticulous and precise system modeling, optimizing the damping parameter and constant of inertia in a Virtual Synchronous Generator (VSG) based frequency control system is difficult. In order to replace the traditional VSG controller, this study suggests a VI emulator based on a Fuzzy Logic Controller (FLC) that mimics automatic frequency control that continously monitors and controls the system frequency, which is a direct indicator of the balance between power generation and consumption.The proposed system provides improved frequency dynamics. The proposed FLC-VI emulator is implemented on an autonomous microgrid system powered by solar photovoltaic. The frequency dynamics of the system on the addition and removal of local loads at multiple instances are analysed. The attained results are compared with those of a VSG controller with improved droop coefficients. It is observed that the frequency nadir of the system with suggested FLC-VI emulator has improved to 49.9835 Hz from 49.8785 Hz and the rate of change of frequency is improved from −0.6 Hz s −1 to –0.2 Hz s −1 when compared to the system with VSG controller. Additionally, the suggested method maintains almost the same frequency during disturbances and minimizes active power oscillations.