In the modern power systems, the penetration level of Renewable Energy Sources (RESs) is significantly increasing. Where, many conventional generation units are being replaced by the RESs based on the power electronic devices (i.e., inverters and converters), this will reduce the overall system inertia. Moreover, the intermittent nature of the RESs might be caused large frequency/voltage deviations. Hence, these disturbances threaten preservation the power system stability and can lead to system collapse. Also, the Load Frequency Control (LFC) action will not be sufficient to maintain the system frequency at the standard value. Therefore, from the perspective of LFC, this paper proposes an application of Superconducting Magnetic Energy Storage (SMES) based on an optimal PID controller, which is optimally designed by the Particle Swarm Optimization (PSO) to enhance the frequency stability of the Egyptian Power System (EPS) due to high RESs penetration. In this paper, the SMES can be used as a feedback controller with the aim of supporting the frequency control loops (i.e., primary and secondary frequency controls) for frequency stability enhancement of the EPS. Moreover, to validate the effectiveness of the proposed control strategy, this is compared with both the optimal LFC with/without the effect of conventional SMES. The obtained simulation results by Matlab/Simulink software reveal that the proposed control strategy achieved superior dynamic responses satisfying the LFC requirements in all test scenarios. Consequently, the frequency stability is improved regarding peak undershoot, peak overshoot, and settling time.