Smart grids rely on Automatic Generation Control (AGC) systems to maintain the balance between demand and supply, highlighting the importance of cybersecurity in daily operations. The increasing complexity and interconnectivity in smart grids necessitate robust measures against cyber-attacks targeting both physical and cyber aspects. Understanding cyber-attacks and their mitigation method is the key to building effective cybersecurity defenses for these critical systems. In this paper, the mitigation of False Data Injection (FDI) attacks is achieved by utilizing ADRC controller. Active Disturbance Rejection controller (ADRC) techniques offer robust performance in the presence of uncertainties and disturbances, making them suitable for enhancing the security and resilience of AGC systems in smart grids. By leveraging ADRC, the smart grid can effectively detect anomalies and mitigate the impact of foreign direct investment attacks, thus ensuring the stability and reliability of the power distribution network. This approach aligns with the growing need for proactive defense mechanisms in the face of evolving cyber threats targeting critical infrastructure. Furthermore, the consolidation of cyber communications networks and physical control systems within the energy smart grid introduces new risks that need to be understood and mitigated. Integrating cyber and physical dynamics in risk management is crucial for addressing smart grid vulnerabilities. This includes analyzing system vulnerabilities and developing mitigation techniques to ensure AGC system security and resilience. OPAL-RT’s seamless integration with physical hardware enables Hardware-in-the-Loop testing, fostering interaction between simulated and tangible hardware in a closed-loop environment.