Performance Evaluation of Redox Flow Battery Based Virtual Inertia and GWO Optimized Fuzzy PID Control for Frequency Stability Enhancement in Low Inertia Power Systems

Abstract:-The increasing penetration of inverter-interfaced renewable energy sources has significantly reduced the effective inertia of modern power systems, leading to severe frequency stability challenges. Low-inertia operation results in large frequency deviations, high rate of change of frequency (RoCoF), and increased risk of system instability following disturbances. This paper presents a comprehensive performance evaluation of a Redox Flow Battery (RFB)–based Virtual Inertia Control (VIC) strategy combined with a Grey Wolf Optimizer (GWO)–optimized Fuzzy Self-Tuned PID controller for frequency stability enhancement in low-inertia power systems. The proposed framework is evaluated on a two-area interconnected power system under conventional, renewable-integrated low-inertia, and virtual-inertia-supported operating conditions. Extensive simulation studies are carried out to analyze frequency deviation, RoCoF, mechanical power response, overshoot, settling time, and ITAE indices. The results demonstrate that the proposed RFB-based VIC with intelligent control significantly improves both transient and steady-state frequency performance, providing a robust and scalable solution for renewabledominated low-inertia power grids

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