Citation: Bouarroudj, N.; Houam, Y.; Djari, A.; Feliu-Batlle, V.; Lakhdari, A.; Benlahbib, B. A Linear Quadratic Integral Controller for PV-Module Voltage Regulation for the Purpose of Enhancing the Classical Incremental Conductance Algorithm. Energies 2023, 16, 4532. https://doi.org/10.3390/en16114532 Academic Editor: Anastasios Dounis Received: 3 May 2023 Revised: 24 May 2023 Accepted: 1 June 2023 Published: 5 June 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article A Linear Quadratic Integral Controller for PV-Module Voltage Regulation for the Purpose of Enhancing the Classical Incremental Conductance Algorithm Noureddine Bouarroudj 1 , Yehya Houam 1 , Abdelhamid Djari 2 , Vicente Feliu-Batlle 3, * , Abdelkader Lakhdari 1 and Boualam Benlahbib 1 1 Unité de Recherche Appliquée en Energies Renouvelables, URAER, Centre de Développement des Energies Renouvelables, CDER, Ghardaïa 47133, Algeria; autonour@gmail.com (N.B.); yahiahouam@gmail.com (Y.H.); lakhdari_abdelkader@hotmail.com (A.L.); bouallam30@gmail.com (B.B.) 2 Electrical Engineering Department, Echahid Cheikh Larbi Tebessi, University-Tebessa, Tebessa 12022, Algeria; abdelhamid.djari@univ-tebessa.dz 3 School of Industrial Engineering and Instituto de Investigaciones Energ’eticas y Aplicaciones Industriales, University of Castilla-La Mancha, Av. Camilo Jose Cela, S/N, C.P. 13001 Ciudad Real, Spain * Correspondence: vicente.feliu@uclm.es Abstract: As a result of the exhaustion of fossil energy sources and the corresponding increase of their negative environmental impact, recent research has intensively focused on regions of alternative energy resources and, especially, on solar energy. Slow tracking of the maximum power point (MPP) and fluctuations around the MPP reduce the efficiency of photovoltaic power generation systems (PV). This study offers a novel design for the MPPT controller, which we refer to as the “hybrid IC-LQI approach”, which combines the incremental conductance (IC) technique and the linear quadratic integral (LQI) controller based on the boost converter’s small signal model. We conduct a comparative study of the proposed hybrid IC-LQI, and the classical one-stage IC technique in order to show the effectiveness of our proposal under three different scenarios of weather conditions and load. According to simulation findings, the proposed hybrid IC-LQI approach has a high tracking efficiency of up to 98.92%, owing to faster tracking of MPP with very large reduction of oscillations. On the other hand, the IC technique provides less efficiency, up to 96.1%, showing very slow tracking and high oscillations. The presented analysis of the results confirms the superior performance of the developed hybrid IC-LQI technique to the classical IC technique. Keywords: PV-system; MPPT; IC-algorithm; IC-LQI algorithm 1. Introduction Recent research shows that, in recent years, the global demand of photovoltaic energy in power generation systems is growing very fast. Moreover, the recent evolution of the equipment of PV energy systems and their usage-related factors, such as the increase of PV cell effectiveness, the decrease of the manufacturing and installation costs, and the enhanced structural insertion to buildings, have increased the demand for these systems [1]. However, the low efficiency of the power conversion of MPPT controllers in PV power production systems remains as one of the biggest barriers to operate these systems at the maximum extracted power point, which is a very important problem that is worth studying. Indeed, improving the yield of MPPT controllers automatically implies a great improvement of the overall system yield [2]. In this context, it should be noted the negative impact of the variation of weather conditions-like solar irradiation and ambient temperature-in the efficiency of the MPPT controller [3]. Since the change of weather conditions is a persistent problem throughout the year, the tracking of the MPP of the PV-systems is a difficult problem that has been approached using several techniques. Energies 2023, 16, 4532. https://doi.org/10.3390/en16114532 https://www.mdpi.com/journal/energies