The presented work examines load frequency control (LFC) to develop the dynamic behavior
of the power system under different load disturbances that have occurred in multi-interconnected
power systems. An artificial bee colony (ABC) algorithm is proposed to design an optimal proportional
integral derivative (PID) controller simulating the LFC installed in a hybrid hydro-thermal
interconnected power system. The proposed approach incorporating ABC is employed to determine
the optimal parameters of the controller during load disturbance applied on one area. The integral
time absolute error (ITAE) of the frequency and exchange power violations is considered as the
target to be minimized. Moreover, integral absolute error (IAE) and sum squared error (SSE) are
calculated. To prove how the proposed model controller is effective, two-interconnected power
systems are presented during a wide range of operating cases, and then the behavior of the proposed
controller is compared to that of the designed via a chef-based optimization algorithm (CBOA),
seagull optimization approach (SOA), and sine cosine approach. Regarding the 5% disturbance on
the thermal plant, the ABC outperformed the other approaches hence achieving the best fitness value
of 1.80936, IAE of 3.147938, and SSE of 0.1787486. On the other hand, during a 5% disturbance on the
hydro plant, the ABC succeeded in getting ITAE, IAE, and SSE with values of 3.43291, 3.630509, and
0.5233815, respectively. The efficiency and prevalence of the proposed LFC-PID is confirmed by the
achieved results.