Voltage and Frequency Recovery in Microgrids by System Partitioning

Recently, load shedding (LSH) is attracting more attention in stability margin enhancement of voltage andfrequency in micro-grids. This paper introduces a regionalization-based multi-level technique (RMLT) via acombination of frequency and voltage LSH in inverter-based autonomous AC distribution systems. The aim is tosimultaneously restore voltage and frequency to their desired ranges in the event of severe disturbances and also inemergency conditions. In the RMLT, to determine the proper load to be shed and to enable LSH in the systemoperation mode (i.e., real-time mode) following each pernicious event, it is proposed that a recurrent online studybe performed on network topology and the sensitivity of voltage to real power. In this case, the quick achievement ofaccurate results implies the regionalization of the system into several zones from the point of view of networktopology and voltage and the assignment of an agent to each zone.