BESS Reserve-Based Frequency Support During Emergency in Islanded Residential Microgrids

Due to limited reserves and 100% inverter-based resources in an islanded residential microgrid (IRM), large-frequency oscillations may arise during load/generation fluctuations. As an independent grid-forming unit, a battery energy storage system (BESS) can participate in load-frequency control (LFC) to achieve environment-friendly and reliable supply in IRMs. The formation of an interconnected islanded residential microgrid (IIRM) system and coordinated active power interchange among IRMs can help overcome BESS units limited reserve constraints. In this work, a reserve control (RC) level is proposed to be added in the conventional LFC architecture to provide frequency support to disturbance-affected areas with the help of a set of BESS units available reserve capacity. Following a significant disturbance detected, the RC level is activated based on their pre-defined contracted demands and net generation change information. The RC level also considers real-time monitoring of each microgrid's active power reserve to avoid frequency instability during emergency conditions. System performance with the proposed LFC model is analyzed with extensive tests conducted on a CIGRE TF C6:04:02 benchmark IIRM system. The proposed algorithms are also validated using a real-time digital simulator with hardware-in-the-loop setup.