A Sine-Cosine Algorithm Optimized PI-PD Cascade Controller for Load Frequency Control

Frequency in power systems experiences continual variations, making the load frequency problem extremely challenging to address. This paper presents a thorough exploration of this problem in a two-area networked power system configu-ration, featuring thermal and geothermal power plants (GTPP) in the respective areas. The study presents detailed modeling of the entire system, including generators, loads, tie lines, and small-signal models for both thermal and geothermal turbines. A cascade control structure employing proportional-integral (PI) and proportional-derivative (PD) controllers (PI-PD controller) is implemented for frequency regulation. Moreover, a population-based sine-cosine algorithm (SCA) effectively optimizes the value of controller gains. The performance of the proposed SCA-based PI - PD controller is compared with conventional control strategies like I, PI, and PID controllers. This analysis demonstrates that the recommended coordinated technique is superior at maintaining system stability and frequency regulation. Further-more, sensitivity analyses are carried out to evaluate the PI - PD controller's robustness under varying operating conditions. These analyses involve modifying system parameters such as small load perturbation (SLP) and area capacity.