maintaining and improving voltage and frequency stability in ac microgrid using adaptive load shedding and battery storage

In recent years, due to economic, technical, and environmental limitations, the expansion of microgrids and their integration with the main distribution network has become an effective solution for optimal use of the power grid. this paper used a hierarchical control strategy in the first and second layers to deal with slight and heavy disturbances that occurred in the islanding mode of operation. the first level is responsible for power sharing using the droop control method, and the second level is tasked with restoring frequency and voltage stability in the case of large disturbances that may lead to collapse and blackout in a microgrid. in this paper, using an energy storage system(battery) and a static synchronous compensator, the stability of important variables of the microgrid is maintained and improved when a small-scale disturbance occurs in the islanding mode of operation. this paper proposes a new adaptive load shedding method with inertia update to maintain frequency stability during large-scale power imbalance. loads with lower priority are shed, and important variables of the network, i.e., voltage and frequency, are returned to their nominal value. the results show that the control structure in different conditions may maintain the frequency and voltage in the nominal range of the microgrid. the simulations are carried out in matlab software.