This paper presents the Load Frequency Control of two modern interconnected power systems. Area 1 comprises a combination of conventional generators, Solar PV, and Solar Thermal, while Area 2 combines conventional generators with wind and Solar Thermal. Governor dead band and appropriate generation rate constraints are considered for conventional generators in both areas. Additionally, Superconducting Magnetic Energy Storage (SMES) and Battery Energy Storage (BES) are the two forms of energy storage units (ES) included in the system. The three controllers PID, Tilt- Integral-Derivative (TID), and Fractional-Order Proportional-Integral-Derivative (FOPID) are investigated and compared for TAMSPS. The controller gains are optimized using the PSO algorithm. The system dynamic performances are studied with a 1% step load perturbation and random loads in Area 1 with different controllers.