Mitigating Low Inertia Challenges in Renewable Energy-Based Microgrids: A Survey

The integration of Renewable Energy Sources (RES) into power systems has significantly reduced system inertia, increasing frequency deviations and the Rate of Change of Frequency (ROCOF). This paper examines the challenges associated with low-inertia power grids and investigates solutions to maintain stability in systems dominated by renewables, with a focus on advancements from 2020 to 2024. Accurate measurement technologies and advanced computational methods are critical in addressing these issues. Key research areas include Flywheel Energy Storage Systems (FESS) and Gravity Hydro Storage (GHS), both of which are extensively studied for their potential to deliver rapid inertia response and stabilize frequencies during disturbances. Compressed Air Energy Storage (CAES) and Synchronous Condensers have received moderate attention, offering practical but less innovative solutions. Emerging technologies such as Phase-Locked Loop (PLL) Synchronization, Batteries, Ultra-capacitors, and Self-Synchronized PLL are underexplored yet hold immense potential for future research and development. Hybrid inertia solutions are highlighted as a critical pathway for ensuring reliable grid performance. These systems combine the strengths of various technologies to provide both short-term frequency stabilization and long-term energy support. Additionally, the study emphasizes the importance of precise inertia estimation tools and advanced control algorithms to address the unique challenges posed by large-scale RES integration. A comprehensive and forward-thinking approach is essential to manage the transition toward renewable energy dominance. This includes leveraging cutting-edge technologies and fostering innovation in underexplored areas to ensure the stability and resilience of modern power systems.