scholarly journals Research air gap on electromagnetic field of high speed motor under the influence of air gap

2021 ◽  
Vol 2083 (2) ◽  
pp. 022089
Author(s):  
Qi Wang ◽  
Shiyu Xing ◽  
Jian Ma ◽  
Aoxiang Liu
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
High Speed ◽  
Field Model ◽  
Asynchronous Motor ◽  
Air Gap ◽  
Finite Element Software ◽  
Magnetic Field Model ◽  
Air Gap Magnetic Field ◽  
The Magnetic Field

Abstract High speed motor are mainly used in aerospace, petrochemical and NC machining fields. Complex electromagnetic field is distributed in the motor. With the continuous maturity of asynchronous motor technology, research on magnetic field has been rapidly developed. In this paper, the changes of air gap and magnetic field of high speed motor under different working conditions is introduced. The magnetic field model of high-speed motor with Maxwell electromagnetic which established theory through Ansoft finite element software. The distribution of electromagnetic field in the motor is explored. The results show that the magnetic field distribution of induction motor tends to increase with the increase of the air gap magnetic field. Therefore, this study has an important guiding significance for the motor.

scholarly journals A case study of the plasma in the magneto-sheath using the numerical magnetosheath-magnetosphere model and THEMIS measure-ments

2018 ◽  
Vol 145 ◽  
pp. 03004
Author(s):  
Polya Dobreva ◽  
Olga Nitcheva ◽  
Monio Kartalev
Keyword(s):  
Magnetic Field ◽  
Field Model ◽  
Specific Aspect ◽  
Plasma Parameters ◽  
Ion Density ◽  
Magnetic Field Model ◽  
Wind Spacecraft ◽  
The Mean ◽  
The Magnetic Field

This paper presents a case study of the plasma parameters in the magnetosheath, based on THEMIS measurements. As a theoretical tool we apply the self-consistent magnetosheath-magnetosphere model. A specific aspect of the model is that the positions of the bow shock and the magnetopause are self-consistently determined. In the magnetosheath the distribution of the velocity, density and temperature is calculated, based on the gas-dynamic theory. The magnetosphere module allows for the calculation of the magnetopause currents, confining the magnetic field into an arbitrary non-axisymmetric magnetopause. The variant of the Tsyganenko magnetic field model is applied as an internal magnetic field model. As solar wind monitor we use measurements from the WIND spacecraft. The results show that the model quite well reproduces the values of the ion density and velocity in the magnetosheath. The simlicity of the model allows calulations to be perforemed on a personal computer, which is one of the mean advantages of our model.

scholarly journals Retrieving lithospheric magnetisation distribution from magnetic field models

2019 ◽  
Author(s):  
V Lesur ◽  
F Vervelidou
Keyword(s):  
Magnetic Field ◽  
Cost Function ◽  
Spherical Harmonic ◽  
Field Model ◽  
Harmonic Model ◽  
Whole Process ◽  
Magnetic Field Model ◽  
The Cost ◽  
Spherical Harmonic Model ◽  
The Magnetic Field

Summary We investigate to which extent the radially averaged magnetisation of the lithosphere can be recovered from the information content of a spherical harmonic model of the generated magnetic field when combined with few simple hypotheses. The results obtained show firstly that a hypothesis of magnetisation induced by a field of internal origin, even over a localised area, is not sufficient to recover uniquely the radially averaged magnetisation and, secondly, that this magnetisation can be recovered when a constant magnetisation direction is assumed. An algorithm to recover the magnetisation direction and distribution is then described and tested over a synthetic example. It requires to introduce a cost function that vanishes when estimated in a system of coordinates with its Z axis aligned with the magnetisation direction. Failing to find a vanishingly small value for the cost function is an indication that a constant magnetisation direction is not a valid hypothesis for the studied magnetic field model. The range of magnetisation directions that are compatible with the magnetic field model and a given noise level, can also be estimated. The whole process is illustrated by analysing a local, isolated maximum of the Martian magnetic field.

scholarly journals Velocity-Magnetic Field Correlation of Pulsars

1996 ◽  
Vol 160 ◽  
pp. 49-50
Author(s):  
Naoki Itoh ◽  
Takemi Kotouda
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Field Model ◽  
Transverse Velocity ◽  
Distribution Model ◽  
Recent Measurement ◽  
Apparent Correlation ◽  
Magnetic Field Model ◽  
Field Correlation ◽  
The Magnetic Field

Monte Carlo simulations of the evolution of pulsars are carried out in order to compare with the recent measurement of the pulsar transverse velocity by Lyne & Lorimer (1994). The new electron density distribution model of Taylor & Cordes (1993) is adopted in the simulation. Accurate pulsar orbits in the Galactic gravitational field are calculated. It is found that the constant magnetic field model of pulsars can account for the new measurement of the pulsar transverse velocity and the apparent correlation between the strength of the magnetic field and the transverse velocity of the pulsars. The present finding confirms the validity of the constant magnetic field model of pulsars and consolidates the idea that the apparent correlation between the strength of the magnetic field and the transverse velocity of the pulsars is caused by observational selection effects.

scholarly journals Analysis of Juno perijove 1 magnetic field data using the Jovian paraboloid magnetospheric model

2018 ◽  
Author(s):  
Ivan A. Pensionerov ◽  
Elena S. Belenkaya ◽  
Stanley W. H. Cowley ◽  
Igor I. Alexeev ◽  
Vladimir V. Kalegaev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Field Model ◽  
Outer Edge ◽  
Optimal Parameters ◽  
Magnetic Field Data ◽  
Analytic Expressions ◽  
Magnetic Field Model ◽  
Current Systems ◽  
The Magnetic Field

Abstract. One of the main features of Jupiter's magnetosphere is its equatorial magnetodisc, which significantly increases the field strength and size of the magnetosphere. Juno measurements of the magnetic field during the perijove 1 pass have allowed us to determine optimal parameters of the magnetodisc using the paraboloid magnetospheric magnetic field model, which employs analytic expressions for the magnetospheric current systems. Specifically within the model we determine the size of the Jovian magnetodisc and the magnetic field strength at its outer edge.

Influence of inverter output voltage harmonic on surface-mounted permanent-magnet synchronous motor performance

2019 ◽  
Vol 43 (4) ◽  
pp. 515-525
Author(s):  
Hongbo Qiu ◽  
Yong Zhang ◽  
Cunxiang Yang ◽  
Ran Yi
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Permanent Magnet ◽  
Motor Performance ◽  
Permanent Magnet Synchronous Motor ◽  
Torque Ripple ◽  
Synchronous Motor ◽  
Air Gap ◽  
Transient Electromagnetic ◽  
Air Gap Magnetic Field

The application of an inverter is becoming more and more widespread in the surface-mounted permanent-magnet synchronous motor (SMPMSM). A large number of voltage harmonics can be generated by the inverter. The electromagnetic torque, loss, and air-gap magnetic density of the SMPMSM are affected by voltage harmonic. To analyze its influence, taking a 3 kW 1500 r/min SMPMSM as an example, a two-dimensional transient electromagnetic field model is established. The correctness of the model is verified by comparing the experimental data with the calculated data. Firstly, the finite element method is used to calculate the electromagnetic field of the SMPMSM, and the performance parameters of the SMPMSM are obtained. Based on these parameters, the influence of voltage harmonic on motor performance is analyzed quantitatively. Secondly, the influence of the voltage harmonic on the air-gap magnetic field is analyzed, and the influence degree of the time harmonic on the air-gap magnetic field is determined. At the same time, torque ripple, average torque, and loss are studied when the different harmonics orders, amplitudes, and phase angles are contained in voltage, and the variation is obtained. Finally, the variation mechanism of eddy current loss is revealed. The conclusion of this paper provides reliable theoretical guidance for improving motor performance.

Analytical calculation of magnetic field in surface-mounted permanent-magnet machines with air-gap eccentricity

2019 ◽  
Vol 38 (2) ◽  
pp. 893-914
Author(s):  
Jawad Faiz ◽  
Mohammadreza Hassanzadeh ◽  
Arash Kiyoumarsi
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Field Distribution ◽  
Analytical Calculation ◽  
Air Gap ◽  
Magnetic Field Distribution ◽  
Magnetic Flux Density ◽  
Content Type ◽  
Air Gap Magnetic Field ◽  
The Magnetic Field

Purpose This paper aims to present an analytical method, which combines the complex permeance (CP) and the superposition concept, to predict the air-gap magnetic field distribution in surface-mounted permanent-magnet (SMPM) machines with eccentric air-gap. Design/methodology/approach The superposition concept is used twice; first, to predict the magnetic field distribution in slot-less machine with eccentric air-gap, the machine is divided into a number of sections. Then, for each section, an equivalent air-gap length is determined, and the magnetic field distribution is predicted as a concentric machine model. The air-gap field in the slot-less machine with eccentricity can be combined from these concentric models. Second, the superposition concept is used to find the CP under eccentricity fault. At this end, the original machine is divided into a number of sections which may be different from the one for slot-less magnetic field prediction, and for each section, the CP is obtained by equivalent air-gap length of that section. Finally, the air-gap magnetic field distribution is predicted by multiplying the slot-less magnetic field distribution and the obtained CP. Findings The radial and tangential components of the air-gap magnetic flux density are obtained using the proposed method analytically. The finite element analysis is used to validate the proposed method results, showing good agreements with the analytical results. Originality/value This paper addresses the eccentricity fault impact upon the air-gap magnetic field distribution of SMPM machines. This is done by a combined analysis of the complex permeance (CP) method and the superposition concept. This contrasts to previous studies which have instead focused on the subdomain method.

EFFECTS OF THE WIGGLER ON THE HEFEI LIGHT SOURCE STORAGE RING

2009 ◽  
Vol 24 (05) ◽  
pp. 1057-1067
Author(s):  
HE ZHANG ◽  
MARTIN BERZ
Keyword(s):  
Magnetic Field ◽  
Light Source ◽  
Storage Ring ◽  
Field Model ◽  
Beta Function ◽  
Nonlinear Effects ◽  
Magnetic Field Model ◽  
Dynamic Aperture ◽  
Linear Effects ◽  
The Magnetic Field

The Hefei light source (HLS) is a second generation synchrotron radiation light source, in which a superconducting wiggler is installed and operating. The effects of the wiggler on the beam dynamics on the HLS storage ring are studied, in order to make sure the wiggler can operate properly when the ring is working in the high brilliance mode. We generate a model of the magnetic field in the midplane of the wiggler. The 3D magnetic field model is also builded up by COSY infinity 9.0. Both the linear and nonlinear effects of the wiggler are discussed. The vertical tune is changed from 2.535 to 2.567 and the vertical beta function is heavily distorted, while a symplectic tracking study shows the dynamic aperture is only slightly affected by the wiggler. And the wiggler should be able to run on the high brilliance mode after the linear effects get compensated.

Relevance of the magnetic field model for studying the beaming cone of the Jovian decameter emission

2020 ◽  
Author(s):  
Patrick Galopeau ◽  
Mohammed Boudjada
Keyword(s):  
Magnetic Field ◽  
Field Model ◽  
Source Region ◽  
Local Magnetic Field ◽  
Hollow Cone ◽  
The North ◽  
Cyclotron Maser ◽  
Specific Direction ◽  
Magnetic Field Model ◽  
The Magnetic Field

<p>We use five different Jupiter’s magnetic field models (O6, VIP4, VIT4, VIPAL and JRM09) to investigate the angular distribution of the Jovian decameter radiation occurrence probability, relatively to the local magnetic field<strong> B</strong> and its gradient <strong>∇</strong><em>B</em> in the source region. The most recent model JRM09, proposed by Connerney et al. [<em>Geophys. Res. Lett.</em>, <em>45</em>, 2590-2596, 2018], was derived from Juno’s first nine orbits observations. The JRM09 model confirms the results obtained several years ago using older models (O6, VIP4, VIT4 and VIPAL): the radio emission is beamed in a hollow cone presenting a flattening in a specific direction. The same assumptions were made as in the previous studies: the Jovian decameter radiation is supposed to be produced by the cyclotron maser instability (CMI) in a plasma where <strong>B</strong> and <strong>∇</strong><em>B</em> are not parallel. As a consequence, the emission cone does not have any axial symmetry and then presents a flattening in a privileged direction. This flattening appears to be more important for the northern emission (34.8%) than for the southern emission (12.5%) probably due to the fact that the angle between the directions of <strong>B</strong> and <strong>∇</strong><em>B</em> is greater in the North (~10°) than in the South (~4°).</p>

scholarly journals Coronal Loop Mapping to Infer the Best Magnetic Field Models for Active Region Prominences

2013 ◽  
Vol 8 (S300) ◽  
pp. 416-417
Author(s):  
G. Allen Gary ◽  
Qiang Hu ◽  
Jong Kwan Lee
Keyword(s):  
Magnetic Field ◽  
Coronal Loop ◽  
Field Model ◽  
Three Dimensional ◽  
Coronal Loops ◽  
Magnetic Field Model ◽  
Free Parameters ◽  
Field Lines ◽  
Fitness Parameter ◽  
The Magnetic Field

AbstractThis article comments on the results of a new, rapid, and flexible manual method to map on-disk individual coronal loops of a two-dimensional EUV image into the three-dimensional coronal loops. The method by Gary, Hu, and Lee (2013) employs cubic Bézier splines to map coronal loops using only four free parameters per loop. A set of 2D splines for coronal loops is transformed to the best 3D pseudo-magnetic field lines for a particular coronal model. The results restrict the magnetic field models derived from extrapolations of magnetograms to those admissible and inadmissible via a fitness parameter. This method uses the minimization of the misalignment angles between the magnetic field model and the best set of 3D field lines that match a set of closed coronal loops. We comment on the implication of the fitness parameter in connection with the magnetic free energy and comment on extensions of our earlier work by considering the issues of employing open coronal loops or employing partial coronal loop.

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