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Impact Factor (2025): 6.9
DOI Prefix: 10.47001/IRJIET
Impact Factor (2025): 6.9
DOI Prefix: 10.47001/IRJIET
Vol 10 No 5 (2026): Volume 10, Issue 5, May 2026 | Pages: 796-798
International Research Journal of Innovations in Engineering and Technology
OPEN ACCESS | Research Article | Published Date: 31-05-2026
The global transition toward inverter-based resources (IBRs) is significantly reducing the rotational inertia of modern power grids, leading to the emergence of ”weak grids.” This paper provides a rigorous mathematical comparison of Grid-Following (GFL) and Grid-Forming (GFM) inverters under low Short Circuit Ratio (SCR) conditions. We develop full-order linearized state-space models for both topologies, accounting for inner-loop current control, outer-loop voltage/power control, and synchronization dynamics (PLL vs. VSM). Small-signal stability is assessed via eigenvalue trajectories and participation factors. Findings indicate that GFL stability is highly sensitive to PLL bandwidth in weak grids, often leading to sub-synchronous oscillations, whereas GFM inverters provide autonomous frequency support and maintain stability at SCR as low as 1.2. The analytical models are validated through time-domain electromagnetic transient (EMT) simulations, offering a definitive performance benchmark for the 2026 grid architecture.
Grid-forming (GFM), grid-following (GFL), small-signal stability, weak grids, Short Circuit Ratio (SCR), eigenvalue analysis, Virtual Synchronous Machine (VSM).
Ravi Solanki, Naresh Sapate, Gurucharan Mashram, & Preeti Rinhayat. (2026). Small-Signal Stability Analysis and Dynamic Performance Assessment of Grid-Following and Grid-Forming Inverters in Weak AC Power Systems. International Research Journal of Innovations in Engineering and Technology - IRJIET, 10(5), 796-798.
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