Comparative Assessment of Frequency Stability Techniques in Inverter-Based Power Grid

In the context of increased renewable energy penetration through inverter-based power supply, reduced rotating parts in generators impact system inertia, leading to frequency stability challenges. This study assesses three frequency stability methods using MATLAB/Simulink, revealing significant variations. At low loads, grid-forming inverter (GFMI) techniques with droop control and virtual synchronous generator (VSG) outperforms GFLI (grid-following inverter), demonstrating superior stability. At high loads, GFMI with droop control performs better than GFMI with VSG, while GFLI shows superior frequency response. The active power of GFLI with PLL and GFMI with Droop Control remains acceptable at balanced and high loads but oscillates significantly at low loads. Conversely, GFMI with VSG technique overshoots and fluctuates at high loads, reducing below normal levels at low loads. This analysis informs practical choices for frequency stability methods in renewable energy-integrated power systems.