The challenge of controlling frequency deviation becomes more difficult as the complexity of a power network increases. The robustness of the controller has a major impact on the stability of a Modern Power system (MPS). Due to the hybridization of MPS basic AGC controllers (PID, FOPID, and TID) are insufficient to give optimal performance of a plant. This requires a robust controller. So, a novel MPC + PIDN controller has been proposed and evaluated by comparing it with several existing controllers, which gives optimal performance in terms of overshoot, undershoot, and settling time. A new modified Opposition‐based Sea‐horse Optimization (OSHO) method has been suggested to optimize the various controller settings. To demonstrate the OSHO's superiority, it is compared with a few popular, existing meta‐heuristic optimizations. The higher penetration levels of RESs reduced system inertia which further deteriorate frequency response in MPS. To overcome these challenges virtual inertia (VI) is implemented with MPC. VI is applied to improve the performance of the AGC of the interconnected MPS along with emphasizing the nature of intermittent renewable energy sources (RESs) of PV and wind energy. To determine the reliability and flexibility of the proposed controller, analysis has been done under a different situation, including step, random disturbances, and modified IEEE‐39 bus. Finally, the stability analysis is performed on a bode plot and the proposed results are compared with previously published literature. The extensive study demonstrates strong evidence that the suggested control approach is efficient and effective.