Reliance on renewable energy is increasing and generating units are being added to the network. Since renewable power fluctuates significantly, The grid's fluctuation in frequency becomes a crucial problem with access to renewable power generation. In order to improve the penetration of renewable power into the system, there is a greater need for Load Frequency Control (LFC) of the power grid due to the deviation of the system's output of renewable energy.
The PID controller's straightforward design and intuitive concept have demonstrated its efficacy for the LFC. In this research, the virtual synchronous generator is introduced and a Fuzzy Self-Tuned PID (FST-PID) Controller is proposed for inertia control. The proposed FST-PID Controller is applied considering the high penetration of renewable energy and virtual inertia. The effectiveness of the proposed FST-PID controller is compared with the classical PID controller for the Egyptian Power System (EPS) as a study case under different disturbances of load changes. The control technique is employed for variable load with photovoltaic and wind turbine generation systems. The controller design is performed based on Gray Wolf Optimizer (GWO) in each operating condition. The overshot and Integral Time Absolute Error (ITAE) are considered as comparison measures. The results demonstrate the efficacy of the proposed FST-PID for inertia control with high penetration of renewable energy. The results show that the proposed FST-PID Controller has an overshot less than the classical PID controller by 25% and ITAE by 45%.