Frequency regulation and stability enhancement of inverter-based renewable power systems

System inertia has been greatly reduced by the growing integration of inverter-based renewable energy sources (RES), such as wind and solar photovoltaics. This has created new difficulties for frequency regulation and grid stability in general. Because inverter-based resources don't have intrinsic inertia like old synchronous generators do, modern power systems are more vulnerable to frequency variations during disruptions. To address these issues, this research compares three sophisticated inverter control strategies: Virtual Synchronous Machine (VSM), droop control with virtual inertia, and traditional droop control. The frequency response and Rate of Change of Frequency (RoCoF) under an abrupt load disturbance were evaluated using MATLAB/Simulink simulations. The results demonstrate that adding virtual inertia greatly improves transient performance even while droop control only offers rudimentary frequency support. With smoother frequency profiles and better damping properties, the VSM method performs better than both. These results offer important insights for future inverter control strategy and deployment, and they show how VSM might enable frequency-secure operation of low-inertia, renewable-rich grids.