International Journal of Electrical and Computer Engineering (IJECE) Vol. 15, No. 3, June 2025, pp. 2713~2725 ISSN: 2088-8708, DOI: 10.11591/ijece.v15i3.pp2713-2725  2713 Journal homepage: http://ijece.iaescore.com Enhancing linear quadratic regulator and proportional-integral linear quadratic regulator controllers for photovoltaic systems Mohamed Assabaa 1,3 , Adel Bouchahed 2,3 , Abdellah Draidi 3 , Boudjemaa Mehimmedetsi 4 , Ahmed Belhani 2 1 Laboratoire de Traitement de Signal, Department of Electronics, Faculty of Science and Technology, University of Constantine 1, Constantine, Algeria 2 Laboratoire Satellites Intelligence Artificielle Cryptographie et Internet des Objets, Department of Electronics, Faculty of Science and Technology, University of Constantine 1, Constantine, Algeria 3 Electromechanical Department, Institute of Science and Applied Techniques, University of Constantine 1, Constantine, Algeria 4 Electromechanical Department, Institute of Science and Technology, Abdelhafid Boussouf University Center, Mila, Algeria Article Info ABSTRACT Article history: Received Sep 4, 2024 Revised Dec 15, 2024 Accepted Jan 16, 2025 This article introduces the linear quadratic regulator (LQR) control and the hybrid linear quadratic regulator proportional-integral (LQR-PI) control, both applied to a photovoltaic system coupled with a DC-DC boost converter. The converter outputs direct current electrical energy to power direct loads. Two robust control correctors, based on the LQR and LQR-PI methods, are designed to enhance the static and dynamic performance of the PV DC-DC boost system. These controllers aim to minimize oscillations and overshoots while ensuring stability across varying solar conditions, thereby optimizing operation around the maximum power point. The disturb and observe maximum power point tracking (MPPT) technique, integrated with the LQR and LQR-PI controllers, ensures system functionality under disturbances. The novelty of this work lies in the development of a MATLAB control block diagram capable of regulating the reference voltage provided by the perturb and observe (P&O) MPPT algorithm. MATLAB simulations demonstrate the robustness and high performance of the LQR and LQR-PI controllers, validating the efficacy of this boost converter control strategy. Keywords: DC-DC boost converter LQR and LQR-PI corrector P&O MPPT Photovoltaic panel PV PWM control This is an open access article under the CC BY-SA license. Corresponding Author: Mohamed Assabaa Laboratoire de Traitement de Signal, Department of Electronics, Faculty of Science and Technology, University of Constantine 1 Constantine, Algeria Electromechanical Department, Institute of Science and Applied Techniques, University of Constantine 1 Constantine, Algeria Email: mohamed.assabaa@umc.edu.dz 1. INTRODUCTION Photovoltaic (PV) systems are increasingly being adopted as a viable solution for harnessing solar energy, especially in isolated areas where access to centralized electricity networks is unavailable. However, these systems encounter notable challenges due to the irregular availability of sunlight, resulting in variations in voltage, current, and power output. To mitigate these issues, maximum power point tracking (MPPT) techniques are commonly employed to optimize energy capture under fluctuating conditions. Furthermore, advanced control strategies, such as proportional-integral (PI), linear quadratic regulator (LQR), and model predictive control, have been explored to enhance operational stability and overall system performance.