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This paper presents the results of the research of a drive with a three-phase switched reluctance motor (SRM) with a C-dump converter, supplied from a mains rectifier. Using the tested C-dump converter for a three-phase mains-powered SRM, a significant increase in output power and speed range was achieved, with a limited capacitor charging voltage close to the source supply voltage, compared to a drive with a converter based on asymmetric half-bridges. Previous studies have only included a battery-powered drive with a two-phase motor with a capacitor charging voltage many times higher than the source voltage. The converter is designed for drives that do not require braking with energy recovery, such as fans and pumps. The mathematical model of the drive is discussed and the simulation results are presented. Experimental tests of the drive were carried out to verify the simulation results. The characteristics of the tested drive were compared with the characteristics of the drive with a typical power supply system.

Current polyamide lithium extraction nanofiltration membranes are susceptible to chlorine degradation and/or low permeance, two problems that are hard to reconcile. Here we simultaneously circumvented these problems by designing a quaternized-spiro piperazine monomer and translating its beneficial properties into large-area membranes (1 × 2 m 2 ) via interfacial polymerization with trimesoyl chloride. The quaternary ammonium and spiral conformation of the monomer confer more positive charge and free volume to the membrane, leading to one of the highest permeance (~22 L m −2 h −1 bar −1 ) compared to the state-of-the-art Mg 2+ /Li + nanofiltration membranes. Meanwhile, membrane structures are chlorine resistant as the amine–acyl bonding contains no sensitive N-H group. Thus the high performance of membrane is stable versus 400-h immersion in sodium hypochlorite, while control membranes degraded readily. Molecular simulations show that the high permeance and chlorine resistance, which were reproducible at the membrane module level, arise from the spiral conformation and secondary amine structures of the monomer. It is a current challenge to design chlorine-resistant polyamide lithium extraction nanofiltration membranes with high permeance. Here the authors address this challenge and produce large-area membranes by the interfacial polymerization of a quaternized-spiro piperazine monomer and trimesoyl.

This paper presents a detailed literature review on switched reluctance motor (SRM) and drive systems in electric vehicle (EV) powertrains. SRMs have received increasing attention for EV applications owing to their reliable structure, fault tolerance ability and magnet free design. The main drawbacks of the SRM are torque ripple, low power density, low power factor and small extended speed range. Recent research shows that multi-stack conventional switched reluctance motors (MSCSRM) and multi-stack switched reluctance motors with a segmental rotor (MSSRM-SR) are promising alternative solutions to reduce torque ripples, increase torque density and increase power factor. Different winding configurations such as single-layer concentrated winding (SLC), single layer mutually coupled winding (SLMC), double layer concentrated winding (DLC), double layer mutually coupled winding (DLMC) and fully-pitched winding (FP) are introduced in the literature in recent years to increase average torque and to decrease torque ripples. This research analyzes winding methods and structure of the SRMs, including conventional and segmental rotors. They have been compared and assessed in detail evaluation of torque ripple reduction, torque/power density increase, noise/vibration characteristics and mechanical structure. In addition, various drive systems are fully addressed for the SRMs, including conventional drives, soft-switching drives, drives with standard inverters and drives with an integrated battery charger. In this paper, the SRM control methods are also reviewed and classified. These control methods include strategies of torque ripple reduction, fault-diagnosis, fault-tolerance techniques and sensorless control. The key contributions of this paper provide a useful basis for detailed analysis of modeling and electromechanical design, drive systems, and control techniques of the SRMs for EV applications.

Using an ultraviolet-based photochemical method, graphene oxide (GO) nanosheets in liquid media can be perforated in minutes to yield nanopores. This scalable etching process partially reduces the GO as well. The perforated GO nanosheets are then used to fabricate membranes that demonstrate a water permeance of 98 LMH/bar and a dye rejection rate above 99% for Direct Red 80. The membrane’s molecular weight cutoff is 600 Da, and its performance remains stable over time. There is only a 17% drop in permeance while keeping rejection above 99% after 96 hours. Permeance through this membrane is five times higher than that of pristine GO membranes, overcoming the typical trade-off between selectivity and permeance. This work demonstrates how designed porosity can provide a materials-based solution for advanced separations.

Switched Reluctance Linear Motors (SRLMs) face constraints in their application scope due to significant electromagnetic force ripple issues, making ripple suppression techniques a critical research focus. To address this, this paper proposes an active suppression strategy based on multi-harmonic current injection. By analyzing the electromagnetic force spectrum, dominant harmonic orders (e.g., 3rd and 5th) contributing to ripple are identified. The strategy superimposes adjustable sinusoidal harmonic components onto conventional rectangular current waveforms to generate optimized composite current profiles. Specifically targeting the end effects unique to linear motors, specific harmonic orders are injected into the reference current within symmetric magnetic field regions. The harmonic-induced forces compensate for inherent ripple, enabling precise waveform regulation and fine-tuned electromagnetic force control. The study employs MATLAB/Simulink simulations to optimize current waveforms and improve electromagnetic force output characteristics, while comparatively evaluating the effectiveness of different harmonic orders.

In electric vehicles, performances of electric vehicle drivetrains depend on the electric machine and the control. Switched Reluctance Machines (SRMs) are today an alternative to rare earth magnets machines such as Permanent Magnet Synchronous Machine (PMSM), which is used in the vehicle drivetrain. Because of its high nonlinear behavior, the classical control designed for SRMs is not sufficient to obtain good performances. The objective of this paper is to make performance and robustness comparisons of the designed robust controllers considering the high nonlinear behavior of SRMs. Sliding Mode Control (SMC) and Super-Twisting Sliding Mode Control (STSMC) are developed and validated by simulation for the velocity control loop and the current control loops of the control strategy. However, an evaluation of their performances compared to classical control based on PI controllers is carried out. For a robustness comparison, a variation of SRM parameters is carried out by simulation using the three controllers. Finally, an experimental validation on a developed test bench using the three controllers is conducted to show that Super-Twisting Sliding Mode Control (STSMC) is the best in terms of performances and robustness for an electric vehicle application.

Engineering surface chemistry to precisely control interfacial interactions is crucial for fabricating superior antifouling coatings and separation membranes. Here, we present a hydrophobic chain engineering strategy to regulate membrane surface at a molecular scale. Hydrophilic phytic acid and hydrophobic perfluorocarboxylic acids are sequentially assembled on a graphene oxide membrane to form an amphiphilic surface. The surface energy is reduced by the introduction of the perfluoroalkyl chains while the surface hydration can be tuned by changing the hydrophobic chain length, thus synergistically optimizing both fouling-resistance and fouling-release properties. It is found that the surface hydration capacity changes nonlinearly as the perfluoroalkyl chain length increases from C 4 to C 10 , reaching the highest at C 6 as a result of the more uniform water orientation as demonstrated by molecular dynamics simulations. The as-prepared membrane exhibits superior antifouling efficacy (flux decline ratio <10%, flux recovery ratio ~100%) even at high permeance (~620 L m −2 h −1 bar −1 ) for oil-water separation. Fouling is a continuous challenge for the effective application of membranes in oily wastewater treatment. Here, the authors present a hydrophobic chain engineering strategy to regulate the surface of graphene oxide-based membranes at a molecular scale for increased antifouling even at high permeance.

Thin-film composite polyamide (TFC PA) membranes hold promise for energy-efficient liquid separation, but achieving high permeance and precise separation membrane via a facile approach that is compatible with present manufacturing line remains a great challenge. Herein, we demonstrate the use of lignin alkali (LA) derived from waste of paper pulp as an aqueous phase additive to regulate interfacial polymerization (IP) process for achieving high performance nanofiltration (NF) membrane. Various characterizations and molecular dynamics simulations revealed that LA can promote the diffusion and partition of aqueous phase monomer piperazine (PIP) molecules into organic phase and their uniform dispersion on substrate, accelerating the IP reaction and promoting greater interfacial instabilities, thus endowing formation of TFC NF membrane with an ultrathin, highly cross-linked, and crumpled PA layer. The optimal membrane exhibited a remarkable water permeance of 26.0 L m -2 h -1 bar -1 and Cl - /SO 4 2- selectivity of 191.0, which is superior to the state-of-the-art PA NF membranes. This study provides a cost-effective scalable strategy for fabricating ultra-selective and highly permeable NF membrane for precise ion-ion separation and small organic compounds removal. Achieving high permeance and precise separation in thin-film composite polyamide (TFC PA) membranes remains challenging. Here, the authors demonstrate the use of lignin alkali derived from waste of paper pulp as an aqueous phase additive to regulate interfacial polymerization process for achieving high performance nanofiltration membranes.

Although three-phase induction motors are the most common motor type in industry, a growing interest has arisen in emerging electric motor technologies like synchronous reluctance motors and permanent magnet motors. Synchronous reluctance motors are a step forward compared to permanent magnet motors when the cost of the system is considered. The main focus of this study is low-power industrial applications, which generally use three-phase induction motors. In this study, the synchronous reluctance motor family is compared at three different power levels: 2.2 kW, 4 kW, and 5.5 kW. The aim of this study is to design and compare synchronous reluctance motors, which can be alternative to the reference induction motors. Finite element analysis is performed for the reference induction motors initially. Their stators are kept the same and the rotors are redesigned to satisfy output power requirements of the induction motors. Detailed design, analysis, and optimization processes are applied to the synchronous reluctance motors considering efficiency, power density, and manufacturing. The results are evaluated, and the optimized designs are chosen for each power level. They are prototyped and tested to measure their performance.

Nanofiltration (NF) membranes with ultrahigh permeance and high rejection are highly beneficial for efficient desalination and wastewater treatment. Improving water permeance while maintaining the high rejection of state-of-the-art thin film composite (TFC) NF membranes remains a great challenge. Herein, we report the fabrication of a TFC NF membrane with a crumpled polyamide (PA) layer via interfacial polymerization on a single-walled carbon nanotubes/polyether sulfone composite support loaded with nanoparticles as a sacrificial templating material, using metal-organic framework nanoparticles (ZIF-8) as an example. The nanoparticles, which can be removed by water dissolution after interfacial polymerization, facilitate the formation of a rough PA active layer with crumpled nanostructure. The NF membrane obtained thereby exhibits high permeance up to 53.5 l m −2 h −1  bar −1 with a rejection above 95% for Na 2 SO 4 , yielding an overall desalination performance superior to state-of-the-art NF membranes reported so far. Our work provides a simple avenue to fabricate advanced PA NF membranes with outstanding performance. Nanofiltration membranes are important for water desalination technologies, but designing membranes that achieve both high permeance and high salt rejection remains challenging. Here, the authors use sacrificial nanoparticles in the membrane fabrication process, leading to crumpled structures with ultrahigh permeance.