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- ItemEnhanced Design and Electromagnetic Analysis of Synchronous Reluctance Machines Using Multi-Material Additive Manufacturing(New York, NY : IEEE, 2025) Akbar, Siddique; Bekele, Yitbarek Tedla; Ebrahimi, Amir; Ponick, BerndThis article comprehensively investigates the design and simulation of synchronous reluctance machines (SynRMs) using multi-material additive manufacturing (MMAM) methods. The main goal is to improve the electromagnetic performance of the machine by strategically utilizing various materials in the rotor's edge bridges to reduce quadrature inductance Lq. A comparative analysis is led on various combinations of magnetic and non-magnetic materials, examining conventionally built machines with single materials alongside additively manufactured machines with both single and multiple materials. A demonstrator machine is built to analyze and determine essential performance parameters, emphasizing the optimization of the rotor. The research establishes an optimized rotor model to enhance electromagnetic performance and examines the operational impacts on electromagnetic torque and torque oscillations. Analytical and simulation findings illustrate the capability of multi-material additive manufacturing to improve the performance of conventional electric machines.
- ItemOutstanding Platinum Recovery by Electrochemical Cathodic Leaching and Redeposition in One-Pot 2 M HCL Solution(Bristol : IOP Publishing, 2025-07-16) Sakthivel, Mariappan; Gandharva, Reshma; Schreiber, Christopher; Drillet, Jean-FrancoisSelective Pt recovery from spent Pt/C gas diffusion electrodes (GDE) is essential for sustainable proton exchange membrane fuel cell and electrolysis industry. This study presents a promising, environmentally friendly approach using pulsed electrochemical cathodic leaching (ECCL) and subsequent electrochemical cathodic deposition (ECCD) in one pot diluted HCl solution. The parameters of ECCL pulse signal were optimized by varying electrolyte concentration, cell voltage, duty cycle, pulse number, and pulse sequence. For aging of GDE, a standard accelerated degradation tests protocol was applied. The amount of dissolved Pt in the electrolyte was evaluated by UV–vis absorption peak intensity at 260 nm that is assigned to Pt (IV) chloro complex ions. A Pt dissolution rate of 99.8% from fresh and aged GDE was achieved in 2 M HCl by applying cell voltage of “only” −3 V (cathode potential: −0.55 V vs RHE) and combining long and short pulse voltage sequences. Remaining Pt in the electrode were determined from electrochemical surface area and thermogravimetric analysis profiles confirming UV–vis results. Finally, proof of concept of one-pot Pt recovery from ECCL electrolyte by means of ECCD step was demonstrated.
- ItemInvestigation of Different Pole Configurations in New Asymmetric Permanent Magnet Synchronous Reluctance Machines(New York, NY : IEEE, 2025-01-13) Ajamloo, Akbar Mohammadi; Ghaheri, Aghil; Ibrahim, Mohamed N.; Sergeant, PeterThis paper investigates the impact of pole number and configuration on key performance characteristics of a new family of asymmetric permanent magnet synchronous reluctance machines (PMSynRMs). New variants of asymmetric PMSynRMs are presented here which integrate distinct interior PM (IPM) poles and reluctance poles into a single lamination. The torque enhancement principle relies on segregating the net torque into components generated by each pole type. Torque enhancement is achieved by optimally shifting the IPM poles relative to the reluctance poles, aligning the torque peaks generated by each pole type. A comprehensive comparative analysis is conducted between the proposed asymmetric and conventional topologies, with identical PM volume, copper loss, frequency, and frame size. The analysis evaluates torque production capability, unbalanced magnetic forces, torque ripple, losses, and power factor. The results reveal that the asymmetric PMSynRMs offer improved torque, power factor, and reduced torque ripple compared to conventional designs for pole numbers 4, 6, 8, and 10. However, some asymmetric designs exhibit the drawback of unbalanced magnetic forces, which should be taken into consideration. Finally, an asymmetric PMSynRM is prototyped and tested to verify the simulation results.
- ItemProperties of Additively Manufactured Soft and Hard Magnetic Cores for Electrical Machines: Methods and Materials − A Review(New York, NY : IEEE, 2025-05-20) Ajamloo, Akbar Mohammadi; Ibrahim, Mohamed N.; Sergeant, PeterAdditive Manufacturing (AM) is an emerging topic in the field of electrical machines (EMs), offering the potential to overcome challenges imposed by conventional manufacturing methods. This paper provides an overview of various AM methods and materials used to manufacture soft and hard magnetic cores for EMs, with a particular focus on their multiphysics properties. Since each AM method involves unique processes—such as particle bonding, melting, or sintering—the resulting microstructural properties of the printed cores differ, leading to varied multi-physics characteristics that require indepth study. The paper outlines both the benefits and challenges associated with AM techniques and materials. Importantly, it explores the detailed properties of Fe-Si and Fe-Co soft magnetic cores as well as hard magnetic cores including NdFeB, ferrite, and alnico printed through different AM methods, comparing them to traditional laminations and commercial hard magnets.
- ItemPrinciple of Torque-Axis Alignment in New Asymmetric PM Synchronous Reluctance Machines: Toward Less-Rare-Earth PM Machines(Piscataway, NJ : IEEE, 2024-12-05) Ajamloo, Akbar Mohammadi; Ghaheri, Aghil; Ibrahim, Mohamed N.; Sergeant, PeterThis article reveals the principle of a new torque-axis alignment technique as the basis for a new class of asymmetric permanent magnet synchronous reluctance machines (PMSynRMs). These machines are characterized by having distinct permanent magnet (PM) and SynRM poles. The objective is to precisely align peak torque from each pole type by adjusting the relative shift angle, minimizing the rare-Earth PM usage. A new analytical model is proposed, segregating torque generated by each pole type in a rotating dq reference frame. The impact of PM pole configuration—surface PM (SPM) and interior PM (IPM)—is examined, and the effects of cross-coupling and saturation are investigated. Two different torque separation models are used to describe key torque characteristics of the machines. The analysis indicates that the asymmetric IPMSynRM and SPMSynRM offer the same torque rating at a significantly lower PM volume usage compared with the conventional PM-assisted synchronous reluctance machine (PMaSynRM). In addition, it is observed that asymmetric IPMSynRM exhibits superior torque performance compared with asymmetric SPMSynRM, attributed to additional reluctance torque generated by IPM poles. Finally, a prototype is manufactured and tested to evaluate the presented principle in the asymmetric topologies.