Indonesian Journal of Electrical Engineering and Computer Science Vol. 29, No. 3, March 2023, pp. 1247~1257 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v29.i3.pp1247-1257  1247 Journal homepage: http://ijeecs.iaescore.com Improve the performance of automatic voltage regulator for power system using self-tuning fuzzy-PID controller Wafaa Saeed Majeed, Amal Ibrahim Nasser, Kassim Rasheed Hameed Department of Electrical Engineering, Al-Mustansiriyah University, Baghdad, Iraq Article Info ABSTRACT Article history: Received Aug 2, 2022 Revised Nov 2, 2022 Accepted Nov 11, 2022 The optimal design of the automatic voltage regulators for a synchronous machine are positively reflected on the quality of voltage stability. This paper is concerned with the design of an AVR by adopting three control techniques. The first one was designed according to the traditional proportional integration-derived (PID) controller while the fuzzy logic was adopted in design the second powerful controller, finally the fuzzy PID controller for an automatic voltage regulator (AVR) based on fuzzy logic technology, self- tuning fuzzy proportional integration-derived (STFPID) have been designed to tuning the gains of the PID controller (KP, KI and KD). To confirm the efficiency of the proposed control systems, a simulation was carried out, and the results showed that the designed STFPID controller achieves the best performance of the AVR system, and gives the preferable tracking low rise time, lower overshoot, least stetting time, minimal steady state error, and gives the ideal response against PID and fuzzy logic technology. Keywords: Automatic voltage regulator Fuzzy logic controller STF PID controller Time response Voltage stability This is an open access article under the CC BY-SA license. Corresponding Author: Amal Ibrahim Nasser Department of Electrical Engineering, Al-Mustansiriyah University Falastin St., Baghdad, Iraq Email: amalalshemmiri@uomustansiriyah.edu.iq 1. INTRODUCTION In general, control techniques seek to gaudiness the system to achieve the desired dynamic response with the basic requirements of feedback system. Most power plant specialists seek to ensure that the synchronous generator's terminal voltages match the predetermined voltages. The synchronous generator voltage is maintained through the generator excitation control. Proportional integration-derived (PID) control systems are the most common for this field [1]. Due to the nonlinear properties and time-varying dynamics of the synchronous generator, conventional controllers cannot guarantee step response throughout the generation range, so conventional control techniques such as Ziegler Nichols PID (ZN-PID), phase margin gain PID (PMG-PID) and the Cohen coon PID (CC-PID) may fail in reaching to optimal parameters for PID controller [2], [3]. To avoid the drawbacks of tuning the parameters of the PID by traditional algorithms, there was a need to rely on metaheuristic tuning algorithms, such as genetic algorithm PID (GA-PID) [4], [5], particle-swarm optimization PID (PSO-PID) [6], ant colony optimization PID (ACO-PID) [4] PID Tuner [7], cuckoo search optimization PID (CSO-PID) algorithm [8], moth fame optimization (MFO) algorithm [9], water cycle optimization PID (WCO-PID) algorithm [10], teaching-learning-based optimization (TLBO-PID) [11], [12]. Hill climbing optimization PID (HCO-PID) algorithm [13] bacteria-foraging optimization PID (BFO-PID) [14]. In spite of metaheuristic tuning techniques have contributed to reducing systems overshoot and steady state error as well as delays in both rise and stabilization time. However, the need for further improvement to reach the optimal values embodied the motivation for this research. The remnant of this paper is organized as