GRID-GUARD: Integration of Grid-Forming Inverter-Based Battery Energy Storage Systems (BESS) for Frequency Stability in Large-Scale Solar PV Penetration

Abstract

The rapid expansion of large-scale solar photovoltaic (PV) penetration reduces the contribution of synchronous generators to system inertia, increasing the risk of rapid frequency deviations and high Rate of Change of Frequency (RoCoF) following sudden generation disturbances. To address these challenges, this paper proposes GRID-GUARD, a conceptual framework integrating Grid-Forming (GFM) inverter control with Battery Energy Storage Systems (BESS) for frequency stability enhancement in low-inertia power systems. Unlike conventional Grid-Following (GFL) inverters, GFM inverters operate as controlled voltage sources and can establish voltage and frequency references without relying on a Phase-Locked Loop (PLL) for grid synchronization. Within the proposed framework, GFM-BESS is conceptually designed to provide fast synthetic inertia and sustained primary frequency response through droop control. Based on a review of relevant literature, a four-phase utility-scale implementation roadmap is developed, comprising dynamic grid modeling, Hardware-in-the-Loop (HIL) validation, protection coordination, and Supervisory Control and Data Acquisition (SCADA) commissioning. A SWOT analysis is further employed to assess the technical, operational, and economic considerations associated with the proposed framework. The resulting framework provides a conceptual basis for the systematic integration of GFM-BESS into power systems with high renewable penetration and identifies key considerations for future modeling, validation, and practical deployment.