Volume 5 Issue 1: March 2026

 This paper experimentally validates the Virtual Current Method (VCM) for predicting the air-gap magnetic field and performance of a 12/10 Flux Switching Permanent Magnet (FSPM) machine. Unlike prior VCM studies, which are mainly limited to analytical derivation or numerical verification, this work provides a full experimental assessment using a fabricated FSPM prototype. The prototype was designed based on the proposed analytical model, and a dedicated test bench was developed to measure back-electromotive force (EMF), electromagnetic torque, and air-gap flux density under various load conditions. Experimental measurements are systematically compared with both analytical predictions and 2D finite element method (FEM) simulations. Results show that the VCM-based model predicts the air-gap flux density with a maximum deviation of 3.6% from experiments and 2.8% from FEM. The prototype delivers an average torque of 5.4 N·m at 5 A root mean square (RMS) phase current, achieving a power factor of 0.89 and efficiency above 93%. These findings confirm that the proposed VCM formulation provides a reliable, low-computational-cost, and experimentally validated tool suitable for preliminary design and performance optimization of FSPM machines. The study highlights the practical applicability of VCM, bridging the gap between analytical models and experimental performance evaluation in advanced electric machine design.

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Solar–hydrogen hybrid systems provide low-carbon and dispatchable energy, yet most existing configurations implicitly assume freshwater availability, thereby overlooking the role of water reuse in water-stressed regions. In semi-arid industrial contexts, the integration of clean energy systems with circular water management is essential for long-term sustainability. This study develops a closed-loop Solar–Green Hydrogen Hybrid System (SGHHS) in which industrial effluent is treated through a membrane bioreactor–reverse osmosis–deionization (MBR→RO→DI) sequence to satisfy proton exchange membrane (PEM) electrolyzer water-quality requirements, while water recovered from fuel-cell exhaust is captured as condensate, achieving an overall water recovery rate of approximately 90%. The proposed system consists of a 22.75 MW photovoltaic array, a 2.25 MW electrolyzer, 450 kg of hydrogen storage, and a 1 MW fuel cell, and is evaluated using a 25-year hourly-resolution simulation framework. Economic performance is assessed through discounted cash-flow analysis, while environmental impacts are quantified using life-cycle assessment. Results demonstrate that integrating water reuse reduces the levelized cost of electricity from 0.10 to 0.0866 USD/kWh, avoids approximately 157,000 tonnes of CO₂-equivalent (tCO₂-eq)emissions, and enables the recovery of nearly 400,000 L/day of process water. By explicitly internalizing water-treatment capital and operating costs alongside water-savings benefits within the energy cost formulation, the study presents a generalizable framework linking hydrogen-based energy systems with circular water infrastructure, supporting industrial decarbonization and Sustainable Development Goals related to clean energy, responsible resource use, and climate action.

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This paper presents an enhanced and comprehensive framework for optimal scheduling of Plug-in Electric Vehicle (PEV) charging by integrating Mixed Strategist Dynamics (MSD) with Forward Dynamic Programming (FDP) to achieve both user-level fairness and grid-oriented optimization. The MSD mechanism generates probabilistic charging strategies that distribute demand across time slots while incorporating equity-based payoff functions to prevent synchronized charging peaks. Building on these probabilistic schedules, an FDP-based deterministic refinement layer is introduced to ensure accurate State-of-Charge (SoC) fulfilment, minimize operating cost, and satisfy grid operational constraints. To ensure technical feasibility, the proposed hybrid MSD–FDP approach is validated on the IEEE 34-bus radial distribution system using Backward/Forward-Sweep (BFS) power-flow analysis. A voltage-penalty cost component is incorporated to restrict bus-voltage deviations within 0.955–1.05 p.u. and to prevent transformer overloading under high EV penetration. The model also integrates Vehicle-to-Grid (V2G) capability, enabling controlled discharging during peak-load conditions to support voltage recovery and improve feeder stability. Simulation results demonstrate that the proposed hybrid framework achieves substantial improvements over MSD-only scheduling and uncoordinated charging. Peak-load demand is reduced by approximately 27%, and the minimum bus voltage is improved from 0.91 p.u. to 0.958 p.u. Additionally, fairness among EVs is significantly enhanced with entropy values averaging 1.77–1.79, indicating balanced access to charging resources. The findings confirm that coordinated charging with V2G support can effectively transform EV fleets into flexible distributed energy assets while ensuring cost efficiency, technical reliability, and scalability for real-world smart-grid applications.

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In Brazil, diesel engines are widely used in freight transportation, particularly in the agricultural and agribusiness sectors, as well as in a significant portion of passenger transport. The main concern associated with these engines lies in the combustion of diesel fuel due to its harmful impacts on both the environment and human health. In order to mitigate these impacts, the replacement of diesel fuel, a fossil energy source, with renewable fuels has been extensively investigated. In this context, the present study evaluates the performance and emission characteristics of a single-cylinder diesel engine operating with partial substitution of diesel by ethanol. Ethanol was injected into the engine intake manifold, while diesel fuel was directly injected into the combustion chamber. Dual-fuel operation tests were conducted with the engine operating at the same power range (approximately 60% of its rated capacity), for four different ethanol flow rates and two distinct intake air flow rates. Overall, for all ethanol flow rates applied and for both adjusted intake air flow conditions, the results showed an increase in thermal efficiency of approximately 9% compared to conventional diesel operation. Regarding emissions, ethanol led to a maximum reduction of approximately 50% in exhaust gas opacity and about 22.8% in NOx emissions, but increased CO. The results indicate that ethanol, a widely commercialized fuel in Brazil, may represent a viable path towards reduced emissions in the transportation sector, while requiring very little modification in current diesel engines.

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Electric switchgear serves as the backbone of any power system; it protects, controls, and isolates electrical circuits. For decades, Sulfur Hexafluoride (SF6) gas has been the insulating and quenching medium of choice. SF6 gas has great dielectric properties, making SF6 gas-insulated switchgear (GIS) compact and highly dependable. However, SF6 gas is highly detrimental to the environment, having a global warming potential of 22,800 times that of CO₂. This makes it imperative that SF6 gas be phased out. At the same time, the rapidly developing complexity of power grids has outpaced the time-based maintenance systems. This article provides a summary of key research to examine the important changes that must be made when addressing the phasing out of SF6 gas and the alternatives for medium and high voltage applications. The article also addresses the shift from time-based maintenance to predictive and condition-based maintenance, as well as the impact of advanced analytics, Artificial Intelligence (AI), and Machine Learning (ML) on the future reliability and efficiency of switchgear. The article concludes by highlighting the importance of the emerging patterns and the need for sustainable and resilient electrical systems. Overall, the discussion highlights the need to prepare for innovation in the industry, as well as the need for sustainable and flexible electrical systems. Meeting these challenges will both reduce negative ecological impacts and protect the future viability of the network systems for power distribution.

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