A Novel Fuzzy PIDF Enhancing PIDF Controller Tuned in Two Stages by TLBO and PSO Algorithms for Reliable AVR Performance

Reliability in control engineering remains a fundamental consideration in the design of controllers for various applications. This study proposes an innovative control design for Automatic Voltage Regulator (AVR) that integrates Fuzzy Proportional-Integral-Derivative with Filter action (Fuzzy PIDF) enhancing PIDF controllers (PIDF + Fuzzy PIDF), which is tuned in a two-stage framework. This framework leverages Teaching-Learning-Based Optimization (TLBO) and Particle Swarm Optimization (PSO) algorithms to find the optimum values of the PIDF and Fuzzy-PIDF controllers’ gains, respectively. The dual-stage design ensures that the controller maintains functionality even if one stage experiences partial failure, thereby enhancing the reliability of both the controller and the system under control. The tuning process for both stages employs the well-known Integral Time Absolute Error (ITAE) cost function in conjunction with the TLBO and PSO algorithms. The reliability of the proposed controller is rigorously tested, demonstrating its ability to deliver robust performance even when operating partially. A comprehensive comparative analysis with existing techniques in the literature demonstrates the superior performance of the proposed PIDF plus Fuzzy PIDF controller. The results show significant improvements in transient response metrics: overshoot is reduced from 0.1559 pu to 0.0211 pu, undershoot from 0.0954 pu to 0.006 pu, and settling time from 0.7568 seconds to 0.2299 seconds. These advancements underscore the controller’s enhanced dynamic stability and precision compared to prior methodologies. Additionally, the robustness of the PIDF + Fuzzy-PIDF controller is evaluated under conditions of system uncertainty and varying load disturbances, with validation conducted in the MATLAB and Simulink environments. The results affirm the controller’s superiority, robustness, and reliability, establishing its potential for successful implementation in real-world applications. This study introduces a novel AVR system characterized by exceptional reliability, robustness, and performance, positioning it as a promising solution for practical deployment.