scholarly journals Analysis of Stator-Slot Circumferentially Magnetized PM Machines with Full-Pitched Windings

2021 ◽  
Vol 12 (1) ◽  
pp. 33
Author(s):  
Huan Qu ◽  
Han Yang ◽  
Zi Qiang Zhu
Keyword(s):  
High Efficiency ◽  
Fault Tolerant ◽  
Geometric Parameters ◽  
Active Length ◽  
Rotor Poles ◽  
Rotor Pole ◽  
High Torque ◽  
Theoretical Analyses

Stator-slot circumferentially magnetized PM machines (SSCMPMMs) have high fault-tolerant capability. In this paper, the SSCMPMMs with full-pitched windings and different stator slot/rotor pole numbers are investigated, together with the influence of key geometric parameters. It shows that the 12 stator-slots 7 rotor-poles (12S7R) machine delivers the highest torque. It is then compared with the SSCMPMM with tooth-coil windings. The results show that when they have the same active length, the 12S7R machine delivers significantly higher torque and higher efficiency. Furthermore, when the machine length is over around 140 mm, the 12S7R machine is more advantageous in producing high torque and high efficiency. A prototype is manufactured and tested to validate the theoretical analyses.

scholarly journals 2D-FEA Based Design and Performance Analysis of Low Weight Segmented Rotor HE-FSM for Light Weight Aircrafts

2018 ◽  
Vol 7 (2.23) ◽  
pp. 152
Author(s):  
Hassan Ali ◽  
Erwan Sulaiman ◽  
Zamri Omar ◽  
M F. Omar ◽  
Faisal Amin
Keyword(s):  
High Efficiency ◽  
Fault Tolerant ◽  
Direct Drive ◽  
Test Analysis ◽  
Torque Density ◽  
Low Weight ◽  
Current Densities ◽  
High Torque ◽  
Field Excitation ◽  
And Performance

All electric aircraft (AEA), is one of the main intentions of the aerospace industry for future. Where electrical machines are capable to provide high torque density and are dominant for the feasibility of direct drive electrical driving force for aircraft applications. Besides, low weight and high torque capabilities, the best candidate solution should also inherently fault tolerant for aircraft applications. For these reasons, a new sort of machine has been familiarized and published in last decade know as flux switching machine (FSM). FSMs contain all excitation sources on stator side with robust rotor structure. According to the type of excitation, FSMs are characterized into three types such as permanent magnet PM FSM, field excitation FE FSM and hybrid excitation HE FSM. PM FSM and FE FSM use PM and FE coil for their excitation sources respectively, whereas both PM and FE coil is used in HE-FSM for excitation. Subsequently, these machines have shown high torque to weight ratios and high efficiency during research in the last decade. Therefore in this paper, a new structure of 12S-8P HE-FSM with segmental rotor has been proposed and analyzed. The proposed segmented HE-FSM has the simple structure using only three PMs and three FECs. The proposed structure is analyzed using commercial 2D FEA package, JMAG-designer ver. 14.0. This paper presents the coil test analysis of segmented HE-FSM to confirm the working principle. Besides, cogging torque, flux strengthening, torque vs current densities and power vs current densities have been analyzed and presented. 

scholarly journals Optimization of Air Gap Length and Capacitive Auxiliary Winding in Three-Phase Induction Motors Based on a Genetic Algorithm

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4407
Author(s):  
Mbika Muteba
Keyword(s):  
Genetic Algorithm ◽  
Design Process ◽  
Power Factor ◽  
High Speed ◽  
High Efficiency ◽  
Air Gap ◽  
Element Analysis ◽  
Three Phase ◽  
High Torque ◽  
Cage Induction Motor

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.

scholarly journals Fault Tolerant Control of PMSM Three-Phase Four-Switch Inverter

2021 ◽  
Vol 2083 (2) ◽  
pp. 022073
Author(s):  
Yuan Cao ◽  
Fuzhi Jing ◽  
Heng Wan
Keyword(s):  
Permanent Magnet ◽  
High Efficiency ◽  
Fault Tolerant ◽  
Permanent Magnet Synchronous Motor ◽  
Fault Tolerant Control ◽  
Synchronous Motor ◽  
High Power Density ◽  
Transportation Industry ◽  
Three Phase ◽  
Fast Dynamic

Abstract Permanent Magnet Synchronous Motor (Permanent Magnet Synchronous Motor, hereinafter referred to as PMSM) has the characteristics of small size, high efficiency, high power density and fast dynamic response, etc., and more and more applications in the transportation industry. This also has higher and higher requirements for the reliability and security of PMSM drivers. In this paper, the fault tolerant control strategy of PMSM based on three phase four switch inverter is proposed based on vector control and the simulation verification is carried out.

A Fault-Tolerant Offset Algorithm for Measured Data with Defects

2014 ◽  
Vol 902 ◽  
pp. 344-350
Author(s):  
Xiang Jia Li ◽  
Ning Dai ◽  
Wen He Liao ◽  
Yu Chun Sun ◽  
Yong Bo Wang
Keyword(s):  
High Efficiency ◽  
Fault Tolerant ◽  
Engineering Application ◽  
Measured Data ◽  
Sphere Model ◽  
High Quality ◽  
Fitting Method ◽  
Enveloping Surface ◽  
Practical Engineering ◽  
Offset Surface

Offsetting of measured data, as a basic geometric operation, has already been widely used in many areas, like reverse engineering, rapid prototyping and NC machining. However, measured data always carry typical defects like caves and singular points. A fault-tolerant offset method is proposed to create the high quality offset surface of measured data with such defects. Firstly, we generated an expansion sphere model of measured data with the radius equivalent to the offset length. Secondly, using the computational geometry application of convex hull, we acquire the data of outermost enveloping surface of this expansion sphere model. Finally, we use local MLS projection fitting method to wipe out existing defects, and generate the high-quality triangular mesh surface of the offset model. The offset surface generated by this method is suitable for practical engineering application due to its high efficiency and accuracy.

scholarly journals High-Torque-Density IPMSM Rotor Pole Geometry Adjustment for Smooth Torque

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 52650-52658 ◽  
Author(s):  
Ilya Petrov ◽  
Pia Lindh ◽  
Markku Niemela ◽  
Eero Scherman ◽  
Juha Pyrhonen
Keyword(s):  
Torque Density ◽  
Rotor Pole ◽  
High Torque

scholarly journals Torque characteristics of double-stator permanent magnet synchronous machines

2017 ◽  
Vol 66 (4) ◽  
pp. 815-828
Author(s):  
Chukwuemeka Chijioke Awah ◽  
Ogbonnaya Inya Okoro
Keyword(s):  
Comparative Study ◽  
Permanent Magnet ◽  
Magnetic Force ◽  
Fault Tolerant ◽  
Synchronous Machine ◽  
Synchronous Machines ◽  
Permanent Magnet Synchronous Machines ◽  
Rotor Position ◽  
Rotor Pole ◽  
Static Torque

Abstract The torque profile of a double-stator permanent magnet (PM) synchronous machine of 90 mm stator diameter having different rotor pole numbers as well as dual excitation is investigated in this paper. The analysis includes a comparative study of the machine’s torque and power-speed curves, static torque and inductance characteristics, losses and unbalanced magnetic force. The most promising flux-weakening potential is revealed in 13- and 7-rotor pole machines. Moreover, the machines having different rotor/stator (Nr/Ns) pole combinations of the form Nr = Ns ± 1 have balanced and symmetric static torque waveforms variation with the rotor position in contrast to the machines having Nr = Ns ± 2. Further, the inductance results of the analyzed machines reveal that the machines with odd rotor pole numbers have better fault-tolerant capability than their even rotor pole equivalents. A prototype of the developed double-stator machine having a 13-pole rotor is manufactured and tested for verification.

scholarly journals Improved Atomization via a Mechanical Atomizer with Optimal Geometric Parameters and an Air-Assisted Component

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 584
Author(s):  
Inna Levitsky ◽  
Dorith Tavor
Keyword(s):  
Liquid Fuel ◽  
High Efficiency ◽  
Geometric Parameters ◽  
Supply Pressure ◽  
Swirl Chamber ◽  
Air Supply ◽  
Wide Range ◽  
Liquid Atomization ◽  
Atomization Characteristics ◽  
Geometrical Dimensions

Atomization of liquid media is a key aim in various technological disciplines, and solutions that improve spray performance, while decreasing energy consumption, are in great demand. That concept is very important in the development of liquid fuel spray atomizers in high-efficiency microturbines and other generator systems with low inlet pressure and a wide range of power supply. Here we present a study of the liquid atomization characteristics for a new mechanical atomizer that has optimal geometric parameters and a preliminary swirl stage. In our air-assisted atomizer, air is introduced through a swirl chamber positioned at the exit of the mechanical atomizer. The optimized mechanical atomizer alone can achieve D32 drop diameters in the range of 80 to 40 µm at water supply pressures of 2 to 5 bar, respectively. The addition of an air swirl chamber substantially decreases drop sizes. At an air–liquid ratio (ALR) equal to 1, water pressures of 2.5 to 3 bar and air supply pressures 0.35 to 1 bar, D32 drops with diameters of 20–30 µm were obtained. In an air-assisted atomizer the parameters of the mechanical atomizer have a much stronger influence on drop diameters than do characteristics of the air-swirl chamber. Using a mechanical atomizer with optimal geometrical dimensions allows limiting the liquid supply pressure to 5 bar; but when an air-assisted component is introduced we can recommend an ALR ≈ 1 and an air supply pressure of up to 1 bar.

Online Measurement for the Thermal Geometric Parameters of Hot Large Forgings

2013 ◽  
Vol 421 ◽  
pp. 453-458
Author(s):  
Wei Liu ◽  
Zhen Yuan Jia ◽  
Ming Xing Li ◽  
Yang Liu ◽  
Yang Zhang
Keyword(s):  
High Temperature ◽  
Measurement Accuracy ◽  
High Efficiency ◽  
Geometric Parameters ◽  
Measurement Time ◽  
Feature Lines ◽  
High Measurement ◽  
High Temperature Components ◽  
Online Detecting ◽  
Geometry Characteristic

t is difficult to obtain high measurement accuracy in online detecting the thermal geometric parameters of hot large forgings, based on machine vision method. In this paper, firstly, a spectrum selective image acquisition method for high-temperature components is proposed, which can successfully reduced the effect of high temperature on image quality. Then, a measurement method based on the coding feature lines for geometric parameters of hot large forgings is employed, which can effectively improve the extraction efficiency of geometry characteristic information of high-temperature components. Experiments on the forging workshop show that measurement accuracy of diameters for cylindrical forging reaches 0.2% and the measurement time is 2.25 seconds; measurement accuracy of lengths for cuboid forging reaches 0.48% and the measurement time is 5.9 seconds. The experimental results have verified the feasibility and high efficiency of the proposed method for measuring the geometric parameters of hot large forgings.

Tungsten Nanowire Metamaterials as Selective Solar Thermal Absorbers by Excitation of Magnetic Polaritons

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Jui-Yung Chang ◽  
Hao Wang ◽  
Liping Wang
Keyword(s):  
Conversion Efficiency ◽  
High Efficiency ◽  
Incident Angle ◽  
Nanowire Array ◽  
Geometric Parameters ◽  
Radiative Properties ◽  
Solar Thermal ◽  
Fdtd Simulation ◽  
Nanowire Diameter ◽  
Solar Absorber

The present study focuses on nanowire-based metamaterials selective solar absorbers. Finite-difference time-domain (FDTD) simulation is employed for numerically designing a broadband solar absorber made of lossy tungsten nanowires which exhibit spectral selectivity due to the excitation of magnetic polariton (MP). An inductor–capacitor circuit model of the nanowire array is developed in order to predict the resonance wavelengths of the MP harmonic modes. The effects of geometric parameters such as nanowire diameter, height, and array period are investigated and understood by the sweep of geometric parameters, which tunes the MP resonance and the resulting optical and radiative properties. In addition, the optical properties and conversion efficiency of this nanowire-based absorber are both demonstrated to be insensitive on incidence angles, which illustrates the potential applicability of the proposed nanowire-based metamaterial as a high-efficiency wide-angle selective solar absorber. The results show that the nanowire-based selective solar absorber with base geometric parameters can reach 83.6% of conversion efficiency with low independence of incident angle. The results will facilitate the design of novel low-cost and high-efficiency materials for enhancing solar thermal energy harvesting and conversion.

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