In this paper, application examples of high-speed electrical machines are presented, and the machine structures categorized. Key issues design control for permanent magnet reviewed, including bearings selection, rotor dynamics analysis design, stress protection, thermal electromagnetic losses reduction, sensorless strategies, as well comparison selection sine-wave square-wave drive modes. Some challenges also discussed, so that future studies could be focused.

Semiconducting nanowire arrays have emerged as a promising route toward achieving high efficiencies in solar cells. Here we propose perpendicular elliptical silicon (PEE-SiNW) array for broadband light absorption thin film Simulation results reveal that enhancement is originated from the split of principal modes well excitation order caused by asymmetry nanowires and enhanced mode coupling between adjacent attained appropriate arrangement nanowires. An ultimate efficiency 29.1% achieved...

Recent advancements in intelligent diagnosis rely heavily on data-driven methods. However, these methods often encounter challenges adequately addressing class imbalances the context of fault mechanical systems. This paper proposes MeanRadius-SMOTE graph neural network (MRS-GNN), a novel framework designed to synthesize node representations GNNs effectively mitigate this issue. Through integrating oversampling technique into GNN architecture, MRS-GNN demonstrates an enhanced capability learn...

A novel platform was constructed by the functionalization of gold nanoparticles for highly efficient electrochemical detection silver ions.

In high-speed surface-mounted permanent magnet (SPM) brushless machines, time- and space-harmonic excitations can induce significant eddy currents flowing in the rotor conductive parts. An effective measure to suppress is employ a copper shield between magnets retaining sleeve. this article, Fourier-based analytical model proposed evaluate current losses. The set up cylindrical coordinate system able compute fields losses all domains, that is, sleeve, shield, magnets, shaft. Although it...

A permanent magnet synchronous reluctance machine (PMSynRM) is studied in this article. It has a stack of surface-mounted (SPM) rotor and (SynR) rotor, which are axially combined on the shaft. Unlike traditional PM-assisted SynR (PMASynRM), magnets not located flux barriers therefore, have no more geometric confliction between them. The two stacks can be circumferentially shifted to any relative angle. Clearly, shifting angle axial length ratio stacks, together with phase armature current...

This article presents an improved mathematical model of high-speed permanent magnet synchronous machine (PMSM), taking the rotor eddy current reaction effect into account. The conventional (e.g. MATLAB/Simulink built-in PMSM model) is not capable handling high-frequency behaviors which involves field. Such include, for example, decrease armature winding inductance with frequency, and increase harmonic amplitude under PWM voltage source inverter (VSI) power supply. In model, modeled by...

Silicon nanowire-based arrays have demonstrated superior light trapping properties and great potential for next-generation photovoltaics. In this paper, we propose a perpendicular elliptical nanocone (PENC) array solar cell, which introduces an asymmetry in the direction parallel to surface addition normal surface, has been implemented circular (CNC) array. The PENC displays more higher resonant absorption peaks long wavelength compared with CNC newly exhibiting are found be derived from...

We propose a perpendicular elliptical silicon nanohole (PE-SiNH) array for light absorption in thin film solar cells. Our analysis shows that this architecture is capable of increasing the cell by 11.3% comparison to optimal circular SiNH array. The process breaking mirror symmetries responsible increase coupled modes. PE-SiNH structures show additional near-zero spatial Fourier components compared with structure, which helps couple more incident into slow Bloch mode interaction between...

This Letter proposes ultrathin InP films consisting of annular nanohole arrays (ANAs) for highly efficient solar cells. By tailoring the inner and outer radii ANAs properly combining antireflection coating (ZnO) back-reflector (Ag), photocurrent generated in based dielectric-semiconductor-metal (DSM) configuration can be increased dramatically by 124.6% with respect to planar cell equal geometric thickness (100 nm). The fact that DSM-ANA structure is able harvest broadband wide-angle...

Single nanowire solar cells show great promise for next-generation photovoltaics and powering nanoscale devices. Here, we present a detailed study of light absorption in single standing semiconductor-dielectric core-shell (CSNW). We find that the CSNW structure can not only concentrate incident into structure, but also confine most concentrated to semiconductor core region, which boosts remarkably cross-section core. The support multiple higher-order HE modes, as well Fabry-Pérot (F-P)...

Rotor eddy current loss reduction, which may largely depend on the pulse-width modulation (PWM) strategies, is a key issue for high-speed permanent magnet synchronous motors (PMSM). In this paper, five PWM strategies are applied to surface-mounted PMSM, respectively, and rotor losses investigated with FEM. Influence of their average switching frequency figured out, so that conclusions reducing in PMSMs can be drawn.

We design a standing semiconductor-dielectric core-shell nanocone array (CSNCA) that can not only concentrate the incident light into structure, but also confine most of concentrated to semiconductor (indium phosphide) core region, which remarkably enhances absorption more material-saving core. find guided resonance features along radial and FP-resonant axial direction by analyzing electric field patterns at spectrum peaks. The CSNCA support multiple higher-order HE modes, in comparison bare...

Semiconducting nanohole arrays have been considered as a promising candidate for high-efficiency solar cells. In this paper, the optical absorption property of randomly rotated elliptical consisting 1×1, 2×2, and 4×4 cells has investigated. It is found that average ultimate efficiency increases with increase size supercell. The array highest efficiency, less sensitive to parameters random rotation angle than 1×1 2×2 arrays. comparison spectra three shows number peaks least, but peak...

Design of high-speed large-power permanent magnet synchronous motor (PMSM) is extremely constrained by the multi-physics couplings and even conflicts, also specification power converter. Therefore, it challenging to achieve a feasible solution design through step-by-step calculation. As study case, 350 kW 13.5 krpm non-salient PMSM was developed optimized with methods. The related aspects include electromagnetic scheme, rotor mechanical optimization, thermal validation computational fluid...

A rotor retaining sleeve is normally a must in high-speed permanent magnet brushless motors to firmly retain the magnets at their positions and ensure integrity. The can be of different materials shapes as long it withstand high centrifugal forces exerted on magnets. On other hand, practically very difficult remove heat from these motors. As inevitable temperature rise results severe performance deterioration even irreversible demagnetization, overall loss, especially eddy current paramount...

Split ratio is one of the most crucial parameters in a permanent magnet synchronous machine (PMSM), which has great impact on both torque or power, and efficiency. Extensive studies have been carried out split optimisation. Compared with regular‐speed machines, high‐speed PMSM more types power loss playing dominant roles, deeper coupling multi‐physics fields. Therefore, special concerns need be made. More comprehensive accurate estimation should implemented; critical mechanical stress...

In recent years, there is a growing demand for permanent magnet synchronous motors (PMSMs) with reduced electromagnetic (EM) vibration, so as to achieve better NVH performance. EM vibration induced by set of spatial and temporal force harmonics, can be evaluated through 2-step finite element (FE) simulation. However, large scale input parameters, it impractical optimize the based on direct FE simulation due time consumption. this paper, response surface generated historical data, replacing...

The electromagnetic vibration and torque ripple are crucial to the NVH performance of permanent magnet synchronous motor (PMSM). In this paper, take a with 9 slots 6 poles as an example, spatial temporal orders force harmonics under stator stationary reference frame rotor rotating derived. Both theoretical analysis finite element method (FEM) demonstrate differences between harmonic characteristics two frames. Then radial tangential vibrations on simulated compared. dominantly causing...

Rotating machinery is widely used across various industries, making its reliable operation crucial for industrial production. However, in real-world settings, intelligent fault diagnosis faces challenges due to imbalanced data and the complexity of neural network models. These are particularly pronounced when defining decision boundaries accurately managing limited computational resources real-time machine monitoring. To address these issues, this study presents KDE-ADASYN-based MobileNet...

In order to improve the high temperature oxidation resistance of Ti6Al4V alloy, in-situ TiN-Ti composite coatings were prepared with Ti-Cr-Ni-Nb powders by plasma transferred arc welding. Nitrogen gas was used as transport and provided N source for formation reaction TiN. Microstructure features behaviors studied. The phases in TiN, Ti, CrN, NiTi. It clearly observed that TiN particles evenly distributed Ti matrix. A little Nb atom dissolved particles, others By comparing curve alloy...