Solar Energy and Sustainable Development Journal

Enhanced Fuzzy MPPT Controller with Rules Compression for 10 kW Grid-Connected PV System

Hicham Stitou — 2026-04-27

This paper proposes an enhanced fuzzy logic controller (FLC) for photovoltaic (PV) systems, featuring a novel reduced-order design. It introduces a significantly simplified FLC for MPPT in a 10-kW grid-connected PV system. The proposed controller minimizes both the number of input variables and the number of membership functions (MFs). Specifically, it utilizes only a single input, the sum of conductance and its increment, and employs just five rules, a substantial reduction compared to the 25-49 rules typical in standard FLCs. Integrated within a system architecture featuring a DC-to-DC converter and a 3-level voltage source converter (VSC) for grid power transfer via duty cycle control, this highly reduced FLC maintains robust MPPT performance through adaptive responses to varying weather conditions. Consequently, it achieves considerable simplification in implementation complexity without sacrificing operational efficiency. To our knowledge, this FLC is among the few controllers capable of such significant rule reduction while maintaining performance. Key results show that at 1 kW/m², incremental conductance (IC) achieves 99% efficiency compared to FLC’s 96%. Under medium irradiance (0.5 kW/m²), FLC outperforms IC by 5% (93% vs. 88%). For low irradiance (0.2 kW/m²), both reach 95.2%. Under large irradiance steps (0.4 to 1 kW/m²), the FLC achieves 22× faster convergence than IC (0.015 s vs. 0.33 s), demonstrating superior dynamic response to abrupt solar variations. This highlights the proposed algorithm’s robustness for dynamic weather scenarios while maintaining competitiveness in steady operation.

Power Management in a PV-Battery Microgrid Using Hybrid ANFIS-Fuzzy Logic MPPT Control and an Adaptive Charge-Discharge Algorithm

Mohamed Amine Atillah — 2026-04-21

This work presents an energy management strategy (EMS) for a microgrid that integrates photovoltaic (PV) panels, a battery energy storage system (BESS), and a grid connection. The primary objective is to maintain a dynamic and reliable power balance between PV generation, local load, BESS, and the grid, while maximizing the self-consumption of solar energy. The system architecture comprises a PV generator whose power is optimized by a hybrid Maximum Power Point Tracking (MPPT) algorithm that integrates an Adaptive Neuro-Fuzzy Inference System (ANFIS) and a fuzzy controller, acting as a PI
regulator. The BESS, made up of Lithium-ion batteries, is managed by a bi-directional DC-DC converter and a fuzzy PI controller, which ensures fine, adaptive regulation of power flows. The core of the innovation lies in the battery management algorithm, which relies on a set of explicit rules to direct power flows. These rules include a strict 10 kW constraint on battery charging and discharging power, crucial for preserving battery life and system safety. The system was simulated considering various cases of irradiance profiles and charging demands of 35 kW and 55 kW, including normal and critical battery state-of-charge (SOC) situations. The simulation results demonstrate the success of the ANFIS-Fuzzy Logic (FL) MPPT control in maximizing energy capture with an error of ± 0.06 KW, while the BESS keeps power balance error below ± 0.02 kW in all tested scenarios. These results confirm the algorithm’s ability to handle critical high and low SOC situations, intelligently redirecting power flows to maintain microgrid stability and power continuity.

DFT Analysis of Structural, Elastic and Optoelectronic Enhancements in LiGeCl₃ Under Pressure for Photovoltaic Applications

Mohammed Miri — 2026-04-04

This study focuses on the crystalline lithium-based perovskite material, LiGeCl₃, with a view to improving its structural, elastic, electronic and optical properties by exploiting the effect of hydrostatic pressure. Combining density of states (DOS and PDOS) analysis with DFT and GGA approximation results, it is shown that the application of pressure reduces the lattice parameter, enhancing self-cohesion and stabilising the atomic structure. At ambient pressure, LiGeCl₃ exhibits semiconducting properties with a direct band gap, dominated by the p-orbitals of Cl atoms in the valence band and Ge in the conduction band. Under increasing pressure (0 to 6 GPa), the band gap is progressively reduced until it disappears at 6 GPa, leading to an electronic transition from a semiconducting to a metallic state. This transition results from the compression of the crystal lattice, which intensifies orbital interactions and causes the valence and conduction bands to overlap. In addition, pressure significantly enhances the optoelectronic properties of LiGeCl₃, including absorption in the visible spectrum, spectral reflectivity and refractive index, making the material more suitable for photovoltaic applications. . These results highlight the potential of LiGeCl₃ in engineering advanced materials for semiconductor and optoelectronic devices, while demonstrating the crucial role of hydrostatic pressure as a tool for modulating material properties

Geometry-Dependent Thermal Transport in Porous Silicon: A Computational Study of Pore Geometry and Porosity Effects

Othman Soubai — 2026-04-04

تستعرض هذه الدراسة كيفية تأثير هندسة المسام والمسامية على التوصيل الحراري وخصائص نقل الحرارة في السيليكون المسامي، باستخدام أداة "أوبن بي تي إي"، وهي أداة حسابية مفتوحة المصدر تعتمد على معادلة بولتزمان للنقل. قمنا بدراسة ثلاث أشكال هندسية للمسام (دائرية، مستطيلة وسداسية) مع نسب مسامية من 5% إلى 45% لدراسة تأثيرها على النقل الحراري الذي يتم بواسطة الفونونات. أظهرت النتائج علاقة واضحة بين التوصيل الحراري وشكل المسام ونسبة المسامية، إذ سجلت المسام ذات الشكل المستطيل أعلى قيم للتوصيل الحراري التي تتراوح من 64.4 واط/(متر•كلفن) عند نسبة 5% من المسامية إلى 26.7 واط/(متر•كلفن) عند نسبة 45% من المسامية. بينما أعطت للمسام الدائرية قيما متوسطة للتوصيل الحراري، تتراوح من 56.8 واط/(متر•كلفن) عند نسبة 5% من المسامية إلى 9.5 واط/(متر•كلفن) عند نسبة 45% من المسامية. أما بالنسبة للمسام السداسية فقد حققت أدنى قيم للتوصيل الحراري، حيث تراوحت بين 54.6 واط/(متر•كلفن) عند نسبة 5% من المسامية إلى 7.2 واط/(متر•كلفن) عند نسبة 45% من المسامية.