Iron Core Research Articles

A novel hybrid magnetic material based on three-phase saturated core fault current limiter

Installing a three-phase saturated core fault current limiter (TSFCL) is an effective method to limit the increasing short-circuit current in high-voltage alternating current (HVAC) systems. However, the traditional TSFCL uses silicon steels as its working material for the iron core, resulting in poor current-limiting effects, requiring a large DC excitation current, and having a slow response speed. Nanocrystalline alloys have advantages such as a lower saturation point, higher permeability in the unsaturated zone, and a steep B–H curve, making them highly suitable for TSFCL’s applications. However, their poor capability which withstands fault hindered their large-scale commercialization. Therefore, this paper proposes a novel hybrid magnetic material based on TSFCL (HMTFCL), where the materials of the working limbs are replaced by nanocrystalline alloys. Compared to TSFCL, the DC excitation current of HMTFCL decreases by 60.5%. And, the HMTFCL reduces the peak short-circuit current by 23%. Last, the magnetic flux intensity inside the working limb of HMTFCL is reduced to zero more quickly.

Rotationally Resolved Mid-infrared Spectroscopy of (16) Psyche

Asteroid (16) Psyche is theorized to be an exposed iron core of a primordial asteroid and is the target of the upcoming NASA Psyche mission. Recent observations of Psyche identified the presence of rotational heterogeneity, a fine-grained regolith, pyroxene, and hydrated minerals on its surface. We obtained rotationally resolved mid-infrared (MIR) spectroscopy of Psyche with the Stratospheric Observatory for Infrared Astronomy to explore its compositional heterogeneity and to assess its mineralogy. We used a thermophysical model of Psyche to estimate and remove its thermal flux at the time of observation to obtain emissivity spectra at 14 different epochs in its rotation. We find that the MIR emissivity does not vary significantly over the rotation of the asteroid, though this may be due to similar aspect angles. We find a lack of mineralogical features, which could suggest that materials on Psyche in the region we observed are not infrared active and consistent with a metal or oxide surface. Differences between the presented spectra and previous studies might indicate a hemispherical compositional dichotomy.

Biocompatibility and proteomic profiling of DMSA-coated iron nanocubes in a human glioblastoma cell line.

Background: Superparamagnetic iron core iron oxide shell nanocubes have previously shown superior performance in magnetic resonance imaging T2 contrast enhancement compared with spherical nanoparticles. Methods: Iron core iron oxide shell nanocubes were synthesized, stabilized with dimercaptosuccinic acid (DMSA-NC) and physicochemically characterized. MRI contrast enhancement and biocompatibility were assessed in vitro. Results: DMSA-NC showed a transverse relaxivity of 122.59mM-1·s-1 Fe. Treatment with DMSA-NC did not induce cytotoxicity or oxidative stress in U-251 cells, and electron microscopy demonstrated DMSA-NC localization within endosomes and lysosomes in cells following internalization. Global proteomics revealed dysregulation of iron storage, transport, transcription and mRNA processing proteins. Conclusion: DMSA-NC is a promising T2 MRI contrast agent which, in this preliminary investigation, demonstrates favorable biocompatibility with an astrocyte cell model.

The Impact of Temperature on the Electromagnet and Structural Optimization of a Solenoid Valve

The mathematical model of the solenoid valve under varying temperatures is constructed to investigate itsperformance and enhance heat dissipation balance. The relationship between temperature and electromagnetic force isdetermined. Electrothermal coupling simulation using COMSOL is conducted, optimizing the outer diameter and lengthstructure parameters of the coil. It is established that the heat dissipation of the coil is influenced by its outer diameter.Subsequently, based on optimized coil structure parameters, an orthogonal experimental design method combinedwith Ansys Maxwell is employed for simulation solution analysis to study the impact of structural parameters such aslength, position, front and rear angles of the magnetic barrier ring in the iron core, armature length, and through-holesize on electromagnetic force. Optimal structural parameters are identified. Results indicate a decrease in steady-stateelectromagnet temperature by 3–4℃, an increase in the initial electromagnetic force by 32.63%, and a rise in the maximumelectromagnetic force by 27.10%.

Comparative the effect of distribution transformer coil shape on electromagnetic forces and their distribution using the FEM

Abstract During the normal life of the transformers, they are subjected to different electromagnetic stresses. One of these stresses is the electromagnetic forces resulting from the passage of short-circuit current in the transformer coils due to internal or external faults and may lead to the failure of the transformer when this electromagnetic force exceeds the threshold level. This work deals with the computation and analysis of leakage magnetic flux and electromagnetic forces when the worst-case fault (symmetrical short-circuit current) occurs in distribution transformer (DT) coils using the finite element method (FEM). The three types of DTs that were adopted in this work are similar in capacity and voltage transformation ratio (250 kVA and 11,000/416 V), but they are different in the shape of coils (oval, cylindrical, and rectangular coils). ANSYS software was used to build two-dimensional models of the three transformers, which were different in coil shapes and in the type of iron core. The objective of this work is to compare the effect of coil shape on the distribution of electromagnetic forces and their value, in order to find out which coil shape is the best to withstand electromagnetic forces when short-circuit current is passed in the coils. The results of the simulation of the finite element models were approximately equivalent to the results of the design calculations that depend on the classical method (the analytical method), but the FEM is more accurate, due to the accuracy of calculating the magnetic flux and its distribution, which cannot be calculated using the classical method. One of the most important contributions of this research is the analysis and calculation of electromagnetic forces for three types of DTs with different coils by applying the same design parameters to all the transformers. The research also contributed to determining the best coil shape by comparing simulation results, and it was found that transformers with cylindrical coils are the best to withstand electromagnetic forces due to the homogeneity of the cylindrical coil structure from all sides.

Hysteresis loss in Brushless Doubly Fed Induction Machines

Brushless doubly fed machine (BDFM) is a potential for future wind energy generation, due to its lower maintenance costs and higher reliability than conventional doubly fed systems. While efficiency and design optimization of the machine has become critical issues recently, no analytical core loss model is investigated in the literature. Furthermore, core loss modeling is different from conventional induction machines, because of double frequency excitation of the machine. In this paper, a dynamical system is used for modeling of hysteretic behavior of iron core, and hysteresis losses of BDFM are analyzed and modeled mathematically. The flux waveforms of BDFM are assumed pure double sine, as in wound rotor BDFM lower harmonic values than nested loop design exist.

A natural biogenic nanozyme for scavenging superoxide radicals

Biominerals, the inorganic minerals of organisms, are known mainly for their physical property-related functions in modern living organisms. Our recent discovery of the enzyme-like activities of nanomaterials, coined as nanozyme, inspires the hypothesis that nano-biominerals might function as enzyme-like catalyzers in cells. Here we report that the iron cores of biogenic ferritins act as natural nanozymes to scavenge superoxide radicals. Through analyzing eighteen representative ferritins from three living kingdoms, we find that the iron core of prokaryote ferritin possesses higher superoxide-diminishing activity than that of eukaryotes. Further investigation reveals that the differences in catalytic capability result from the iron/phosphate ratio changes in the iron core, which is mainly determined by the structures of ferritins. The phosphate in the iron core switches the iron core from single crystalline to amorphous iron phosphate-like structure, resulting in decreased affinity to the hydrogen proton of the ferrihydrite-like core that facilitates its reaction with superoxide in a manner different from that of ferric ions. Furthermore, overexpression of ferritins with high superoxide-diminishing activities in E. coli increases the resistance to superoxide, whereas bacterioferritin knockout or human ferritin knock-in diminishes free radical tolerance, highlighting the physiological antioxidant role of this type of nanozymes.

Design Overview of a Toroidal Fast-Field Cycling electromagnet

In this paper, the design and development of a novel Fast-Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometer’s electromagnet is described. This magnet is tailored to increase the relaxometers’s usability, by increasing its portability capacities. It presents a compact toroidal shaped iron core, allowing to operate in a field range of 0 to 0.21 T, with high field homogeneity (less than 800 ppm in a volume of ≈ 0.57 cm3 ), low power consumption and reduced losses (about 40W). The simulation software COMSOL Multiphysics® is used to characterize the induced magnetic field, the heating and the cooling effects. The proposed optimized layout constitutes an innovative solution for FFC magnets.

The test bench for simulation impact of core saturation on the current transformer on coordination of inverse relay protection

When the measurement-type Current Transformer (CT) is used for protection schemes, this condition causes problems related to the operation of the protection relay. This performance can provide the right output to be captured by the relay when using the CT type of protection system, and measurement CT will be appropriately used as a measurement instrument. When the primary current is greater, the denser the flux flowing in the iron core, and when a certain primary current value is reached, the iron core is unable to accommodate the flux that must be flowed. As a result, the value Es is unable to rise again, so the error ratio begins to rise, and the secondary current output is distorted. This research aims to design a tool that can display the distortion that occurs in the secondary current, and this research will evaluate its impact on the characteristics of the inverse-type overcurrent relay. The research method is R&D (Research & Development) by configuring a prototype analog test table so that saturation occurs on the CT connected to the protection relay. The results of the research Simulation of protection coordination failure due to core saturation can be shown, and the design of core saturation test equipment can be demonstrated. The root cause of core failure can be traced from the disconnection time deviation that occurs at the protection relay. The design of core saturation test equipment can be implemented to display protection failures due to core saturation and show the correlation between the voltage excitation curve and relay disconnection time. Testing CT ratio 30/5 with a burden of 1.5 VA, the operating limit is 183.3% of the primary rated rating, meaning that for CT with a primary rated current of 30 amperes, testing up to 60 amperes shows the results have not occurred core saturation.

Water content of rocky exoplanets in the habitable zone

In this study we investigated the interiors of rocky exoplanets in order to identify those that may have large quantities of water. We modelled the interiors of 28 rocky exoplanets, assuming four different layers – an iron core, a rock mantle, a high-pressure ice layer, and a surface ice/water layer. Due to observational bias, our study is limited to habitable zone exoplanets. We determined a range of possible water mass fractions for each planet consistent with the modelled planetary structures. We calculated the tidal heating experienced by these exoplanets through gravitational interactions with their host stars, assuming a temperature- and composition-dependent Maxwell viscoelastic rheology. Assuming radioactive elemental abundances observed in Solar System meteorites, we also calculated the radiogenic heat flux inside the planets. We estimated the probability of the presence of a thick ocean layer in these planets, taking into account the effect of both tidal and radiogenic heating. Our results showed that Proxima Centauri b, Ross 128 b, Teegarden’s b and c, GJ 1061 c and d, and TRAPPIST-1 e may have an extended liquid water reservoir. Furthermore, extremely high H2O-content of the exoplanets Kepler-62 f, Kepler-1652 b, Kepler-452 b, and Kepler-442 b suggests that these planets may maintain a water vapour atmosphere and may in fact be examples of larger ocean worlds. Upon the discovery of new rocky exoplanets beyond the habitable zone, our study can be extended to icy worlds.

Prototype Design and Construction of 450 VA Permanent Magnetic Sync Generator for Vertical Axis Wind Power Generator House Scale with Low Wind Speed

Permanent magnet synchronous generator (PMSG) is a mechanical electrical machine that can convert motion energy into electrical energy which has two main parts, namely a rotor using permanent magnets and a stator without an iron core which the machine uses for low and low rotations. load torque used as a generator. The driving force for Wind Power Plants (PLTB) which we know is alternative and renewable power plants, the energy source is wind which continues to exist and is easily available, another reason for the need to develop permanent magnet generators for PLTB is the reduction of petroleum, other fossil energy, subsidies continue to cut materials fuel oil for power generation which increases the price of electricity per KWH as well as a global commitment to reduce greenhouse gas emissions. the need for electricity for the community and the high price of electricity as well as the difficulty of installing electricity with a capacity of 450 VA, this study aims to make a prototype of a laboratory-scale permanent magnet generator for wind power plants for residential homes that allows it to be placed close to the ground, no need to be directed towards the wind. blowing, can generate electricity with wind speed from 2.5 m/s, easy operation and low cost. The research method in this study is to conduct a literature study, conduct a wind source mapping survey from several sources to obtain wind speed data nationally, design a prototype and design a permanent magnet generator prototype and finally simulation with calculation capacity of the prototype. The design of the permanent magnet generator prototype for the Wind Power Plant has 12 poles with a rotor speed of 500 rpm (revolution per minute) with capacity of 450 VA.

Effect of Powder Particle Surface Treatment on DC Magnetic Properties of Compacted Iron Cores

Effect of Powder Particle Surface Treatment on DC Magnetic Properties of Compacted Iron Cores

Development of Low-Speed Generator for Rural Energy Self Power Plant

This study investigates the potential for wind energy generation in various regions of Indonesia, which have been identified to potentially produce over 100 megawatts (MW) of electrical energy. In response to the need for rural electrification and the utilization of this wind potential, we developed a low-speed generator suitable for rural, energy-independent power plants. The objectives were twofold: to design a low-speed generator optimized for low rotational speeds reflective of local wind conditions, and to assess its performance in electricity generation. Our research methodology encompassed an analytical comparison of exploratory data and literature to devise a generator design compatible with rural wind patterns. This involved calculating the necessary wind acceleration to actuate the designed generator. Subsequently, a prototype was designed, constructed, and tested, examining variables such as iron core composition, winding wire, magnetic strength, and electrical output under wind-driven conditions. The performance tests revealed that the Low-Speed Generator produced an average voltage output scaling with rotational speed–from 5.3V at 100rpm to 21.1V at 500rpm. The peak voltage output at 500rpm rotation reinforces the generator’s efficacy in higher rotational regimes. Such findings advocate for the Low-Speed Generator’s application as a sustainable solution to the rural energy crisis, aligning with the broader objectives of equitable energy distribution and the Sustainable Development Goals (SDGs).

Effective Material Modelling for Laminated Iron Cores with a T,Φ-Φ Formulation

Effective Material Modelling for Laminated Iron Cores with a T,Φ-Φ Formulation

Design Optimization of an Iron Core for Cup-type AMF Contacts Using Genetic Aggregation Response Surface and Multi-Objective Genetic Algorithm

Design Optimization of an Iron Core for Cup-type AMF Contacts Using Genetic Aggregation Response Surface and Multi-Objective Genetic Algorithm

Dinitrosyl Iron Complex-Derived Nanosized Zerovalent Iron (NZVI) as a Template for the Fe-Co Cracked NZVI: An Electrocatalyst for the Oxygen Evolution Reaction.

Nanosized zerovalent iron (NZVI) Fe@Fe3O4 with a core-shell structure derived from photocatalytic MeOH aqueous solution of dinitrosyl iron complex (DNIC) [(N3MDA)Fe(NO)2] (N3MDA = N,N-dimethyl-2-(((1-methyl-1H-imidazole-2-yl)methylene)amino)ethane-1-amine) (1-N3MDA), eosin Y, and triethylamine (TEA) is demonstrated. The NZVI Fe@Fe3O4 core shows a high percentage of zerovalent iron (Fe0 %) and is stabilized by a hydrophobic organic support formed through the photodegradation of eosin Y hybridized with the N3MDA ligand. In addition to its well-known reductive properties in wastewater treatment and groundwater remediation, NZVI demonstrates the ability to form heterostructures when it interacts with metal ions. In this research, Co2+ is employed as a model contaminant and reacted with NZVI Fe@Fe3O4 to result in the formation of a distinct Fe-Co heterostructure, cracked NZVI (CNZVI). The slight difference in the standard redox potentials between Fe2+ and Co2+, the magnetic properties of Co2+, and the absence of surface hydroxides of Fe@Fe3O4 enable NZVI to mildly reduce Co2+ and facilitate Co2+ penetration into the iron core. Taking advantage of the well-dispersed nature of CNZVI on an organic support, the reduction in particle size due to Co2+ penetration, and Fe-Co synergism, CNZVI is employed as a catalyst in the alkaline oxygen evolution reaction (OER). Remarkably, CNZVI exhibits a highly efficient OER performance, surpassing the benchmark IrO2 catalyst. These findings show the potential of using NZVI as a template for synthesizing highly efficient OER catalysts. Moreover, the study demonstrates the possibility of repurposing waste materials from water treatment as valuable resources for catalytic energy conversion, particularly in water oxidation processes.

Surface structure regulation of sulfidated zero-valent iron by H2O2 for efficient pH self-regulation and proton cycle to boost heterogeneous Fenton-like reaction for pollutant control

Sulfidated zero-valent iron (SZVI) has been widely used in controlling organic pollutants. However, the significant decrease in catalytic activity of SZVI-based Fenton-like systems under neutral and alkaline conditions remains a large problem. Herein, it was found that surface structure regulation of SZVI with H2O2 (HT-SZVI) greatly enhanced its reactivity and efficiently activated H2O2 to oxidize various organics in a wide pH range. The HT-SZVI/H2O2 system exhibited a pH self-regulation capability that stabilized the eventual solution pH at ∼3.5 at the initial pH of 3.0–9.0. The excellent oxidation performance was primarily attributed to surface-bound •OH produced from H2O2 activation by surface Fe(II) sites on HT-SZVI. Additionally, dissolved Fe(II) converted from surface Fe(II) induced proton generation to self-regulate pH. Newly formed high proton-conductive FeS and Fe3O4 shells accelerated the transfer of accumulated protons in solution to iron core to produce Fe(II), enabling efficient proton consumption-regeneration cycle and enhancing •OH production.

A Convolutional Neural Network Based on Attention Mechanism for Designing Vibration Similarity Models of Converter Transformers

A vibration scale training model for converter transformers is proposed by combining attention modules with convolutional neural networks to solve the nonlinear problem of converter transformers in similar processes. Firstly, according to the structure and operating parameters of the converter transformer, a reliable three-dimensional multi-field coupled finite element model was established considering the influence of the winding and iron core component structure on the overall vibration characteristics. By changing different input parameters such as the size and voltage of the finite element model, corresponding output parameters are obtained, and a dataset is established through data expansion for training and verifying the attention convolution model. By analyzing the prediction processes and results of five prediction models on different operating conditions datasets, it is shown that attention convolution has higher accuracy, faster convergence speed, more stable training process, and better generalization performance in the prediction process of converter transformer recognition. Based on the predictive model, a prototype of the proportional vibration model for the converter transformer with scale factor of 0.2 was designed and manufactured. By analyzing the basic experimental items and vibration characteristics of the prototype, the stability of the prototype and the reliability of the prediction model were verified.

A flux pump driven non-soldering closed-loop HTS magnet and its electromagnetic-thermal semi-analytical modelling method

We propose a new flux pump driven non-soldering closed-loop (NSCL) high temperature superconducting (HTS) magnet free of any soldering joints throughout the magnet for persistent current mode (PCM) operation. All the superconducting parts of the magnet are wound directly with HTS closed-loop ring split from an 8 mm REBCO tape using our new cutting scheme free of any soldering requirements. The magnet contains two single-pancake coils connected in series forming a closed circuit through two parallel bridge branches. Two thermal switches set on the two bridge branches control the on–off of the two bridges. A copper coil with iron core installed around one of the bridges is employed as the flux pump to drive the HTS magnet. An electromagnetic-thermal semi-analytical modelling method is proposed to analyse the pumping process by which the transport current in the magnet is calculated. The theoretical limit equation of the saturation current is improved as well. The proposed method can predict the current of the NSCL HTS magnet during the pumping process and provide results that are close to experiments. Experiments verify both the feasibility of the proposed flux pump driven NSCL HTS magnet and the modelling method. The results show that the NSCL HTS magnet works well in the PCM, which provides inspiration to the design of PCM operation of high field HTS magnets. The proposed modelling method also helps guide the design of different forms of HTS magnets and the flux pumps driving them.

Strong enhancement on electron transfer pathway of peroxymonosulfate activation for rapid organic pollutant degradation in wastewater by iron encapsulated into nitrogen-doped carbon: Iron-cores as electron supply stations

Developing high-performance non-radical degradation systems is a valuable strategy to solve the inefficiency of free radical systems in complex aqueous conditions. In this paper, nitrogen-doped carbon materials encapsulating iron-based nanoparticles (Fe@CPAnPyX) were prepared by carbonizing polyaniline-polypyrrole copolymer precursors. Fe@CPAnPyX exhibited outstanding peroxymonosulfate (PMS) catalytic activity and could rapidly degrade 97.40 % of 2,4-dicholophenol (100 mg/L) within 6 min, with kinetic constant reaching 17.2 times than that of CPAnPyX without iron. Adequate reaction pathway investigations showed that, unlike most reported Fe-carbon composites, the Fe@CPAnPyX/PMS system is dominated by electron transfer pathway (97.60 %) after encapsulation of iron-based nanoparticles. The antitheses analysis, structure–activity relationship analysis and density functional theory calculations validated that the N-doped carbon shell, rich in defect and graphitic nitrogen, is the direct component involved in the reaction, while the internal iron core mainly acts as an auxiliary component significantly facilitating the electron transfer pathway by enhancing the overall conductivity and coulomb field of the material and serving as “electron resupply stations” for the external carbon shell. Benefiting from the enhanced non-radical pathway, the Fe@CPAnPyX/PMS system exhibits wide pH applicability (pH = 3.00–11.00), strong resistance to water matrixes, significant electron-rich pollutants selectivity and good reusability (92.58 % degradation efficiency was maintained in the seventh cycle). A custom-made catalytic membrane device exhibited good sustained operational stability, showing a good practical application prospect. This study provides an effective strategy to significantly enhance the non-free radical pathway of carbon-based materials, which promotes the application of non-free radical systems in complex wastewater.