Frequency Stability Enhancement via Virtual Inertia Control Optimization Considering Frequency Nadir Using Firefly Algorithm

System inertia is reducing as more renewable energy sources (RESs) are added to power systems, producing frequency stability issues during power system disturbances. Until then, Virtual Inertia Control (VIC) is considered one of the most effective measures to potentially mimic the inertial response of conventional generators and enhance system stability. The presented method is focused on determining an optimal value of virtual inertia constant of Battery Energy Storage Systems (BESS), including its support in compliance with the code of frequency nadir, which is utilized to increase frequency stability in the system. The Firefly Algorithm (FA) is used for the optimization process, since it is widely used in power system optimization problems. A method to assess the ramifications of frequency instability caused by VIC, using the IEEE 14-bus system as a test model. The simulation results prove that the frequency nadir deviations are remarkably mitigated using the optimized VIC according to the Firefly Algorithm over fixed VIC configurations. Furthermore, the optimized VIC decreases the energy utilized from BESS, while preserving the targeted frequency nadir, thereby providing an effective solution for incorporating RESs into power systems. In addition, the optimized VIC does not require reconfiguring existing frequency protection settings; hence, this is practical and applicable for real-world applications. The FA is compared with Particle Swarm Optimization (PSO), and results indicate that the FA implementation bested the PSO on simulation time and frequency nadir accuracy. This study emphasizes the significance of utilizing FA-optimized VIC to mitigate the impacts of low system inertia in power systems with high RES integration.