Cascaded PIDn-PI controller for LFC of hybrid thermal power systems using quasi-oppositional African vultures optimization

Abstract

With the integration of renewable energy sources, modern power systems are becoming increasingly large and operationally complex. This leads to frequency fluctuations within the system. Therefore, it is essential to implement advanced Load Frequency Control (LFC) to address frequency stability challenges arising from unexpected external disturbances and continuous fluctuations in load demand. We propose a quasi-oppositional African Vultures optimization algorithm (QO-AVOA)-based proportional-integral-derivative filter plus proportional-integral (PIDn-PI) controller to address the LFC problem. The proposed controller is implemented on a two-area interconnected hybrid thermal power system and tuned by minimizing the error index to achieve optimal performance. Other state-of-the-art optimization-based LFCs are employed with the test system, and the outcomes are compared to demonstrate the efficacy of the QO-AVOA-tuned controller. The simulation results confirm that the proposed strategy significantly improves the system response compared to existing methods. Furthermore, the controller’s robustness is verified under random loads, wind disturbances, and parameter variations.