Temperature field calculation and water cooling design of the magnetic field immunity testing system

2021 ◽  
Vol 170 ◽  
pp. 112515
Author(s):  
Ya Huang ◽  
Li Jiang ◽  
Peng Fu ◽  
Zhengyi Huang ◽  
Xuesong Xu
2021 ◽  
Vol 68 (2) ◽  
pp. 1065-1076
Author(s):  
Zhongliang Pei ◽  
Jiwen Zhao ◽  
Juncai Song ◽  
Kaifang Zong ◽  
Zhongyan He ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
L. Wang ◽  
Q. M. Ren ◽  
J. C. Han ◽  
Y. D. Zhang

To eliminate the jump points of multipole angle values after subdivision at low temperature, the magnetic field and temperature field characteristics of a multipole magnetic encoder are analyzed in this study, and the effect of changes in magnetic field strength and temperature field on the precision of angle values is studied. To eliminate the jump point of multipole angle values caused by changes in the temperature field, the suppression method based on single-pole angle value fitting is proposed. The error between the single-pole and multipole angle values is tabulated by the oversampling linear interpolation method, and the precision of fitting single-pole to multipole angle values is effectively improved. The error of the angle value caused by changes in the temperature field is studied and analyzed, and the relationship between the jump angle values and the pole number of the multipole magnetic encoder is obtained. Furthermore, the jump point is compensated for by the jump range of the multipole angle values. Finally, the angle accuracy of the multipole magnetic encoder in a cryogenic chamber is experimentally verified. The experimental results show that the low-temperature jump point compensation method proposed for the multipole magnetic encoder in this paper can effectively suppress the jump of the angle values.


2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Y.D. Zhang ◽  
C. Esling ◽  
M. Calcagnotto ◽  
M.L. Gong ◽  
H. Klein ◽  
...  

A 12 T magnetic field has been applied to the annealing process of a 0.81%C-Fe (wt.%). It is found that the magnetic field shifts the eutectoid carbon content from 0.77 wt.% to 0.83 wt.%. The statistical thermodynamic calculations were performed to calculate the eutectoid temperature change by the magnetic field. Calculation shows that the increase of the eutectoid temperature by a 12 T field is 29∘C. Synchrotron radiation measurements were performed to measure the pole figures of the samples and were analyzed by MAUD to determine the bulk texture of the ferrite phase In the field-treated and non field-treated samples. Results show that although there is no specific preferred orientation appearing by applying the magnetic field, slight enhancement of (001) fiber component occurs in both the sample normal direction (ND) and the transverse direction (TD). This effect might be related to the magnetic dipolar interaction between Fe atoms in the transverse field direction.


2000 ◽  
Vol 18 (4) ◽  
pp. 601-610 ◽  
Author(s):  
STANLEY HUMPHRIES ◽  
JOHN PETILLO

Beam-generated magnetic fields strongly influence the behavior of relativistic electron guns. Existing methods used in ray-tracing codes have limited accuracy and may not correctly represent nonlaminar beams. We describe a technique for the magnetic field calculation in a two-dimensional code based on the assignment of particle currents to the faces of elements in the mesh used for the electrostatic calculation. The balanced calculation of electric and magnetic forces in the same iteration cycle reduces the possibility of numerical filamentation instabilities. With simple rules of assignment on boundary faces, the method also handles field contributions of electrode currents. Several benchmark calculations performed on conformal meshes illustrate the versatility of the technique.


Author(s):  
Brahim Ladghem Chikouche ◽  
Kamel Boughrara ◽  
Dubas Frédéric ◽  
Rachid Ibtiouen

Purpose The purpose of this paper is to propose a two-dimensional (2-D) hybrid analytical model (HAM) in polar coordinates, combining a 2-D exact subdomain (SD) technique and magnetic equivalent circuit (MEC), for the magnetic field calculation in electrical machines at no-load and on-load conditions. Design/methodology/approach In this paper, the proposed technique is applied to dual-rotor permanent magnet (PM) synchronous machines. The magnetic field is computed by coupling an exact analytical model (AM), based on the formal resolution of Maxwell’s equations applied in subdomains, in regions at unitary relative permeability with a MEC, using a nodal-mesh formulation (i.e. Kirchhoff's current law), in ferromagnetic regions. The AM and MEC are connected in both directions (i.e. r- and theta-edges) of the (non-)periodicity direction (i.e. in the interface between teeth regions and all its adjacent regions as slots and/or air-gap). To provide accurate solutions, the current density distribution in slot regions is modeled by using Maxwell’s equations instead to MEC and characterized by an equivalent magnetomotive force (MMF) located in the slots, teeth and yoke. Findings It is found that whatever the iron core relative permeability, the developed HAM gives accurate results for both no-load and on-load conditions. Finite element analysis demonstrates the excellent results of the developed technique. Originality/value The main objective of this paper is to achieve a direct coupling between the AM and MEC in both directions (i.e. r- and theta-edges). The current density distribution is modeled by using Maxwell’s equations instead to MEC and characterized by an MMF.


2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1827-1834
Author(s):  
Kuiyang Wang ◽  
Ren He ◽  
Jinhua Tang ◽  
Ruochen Liu

This article focuses on a new type of permanent magnet-friction integrated brake. The design scheme of integrated brake is proposed. Taking the maximization of braking moment and the minimization of volume as the dual optimization objectives, the particle swarm optimization algorithm is used to optimize the integrated brake, and the main structure parameters of the integrated brake are obtained. Based on the obtained structure parameters, the 3-D model of integrated brake is established. The mathematical models of electromagnetic field and temperature field of integrated brake are given, respectively. Taking a typical braking process as an example, the magnetic field of integrated brake is analyzed based on COMSOL software, which verifies the correctness of the design model of permanent magnet brake. The eddy current loss in the magnetic field of permanent magnet brake and the thermal contact of friction brake are taken as heat sources of the integrated brake, then the temperature field of integrated brake is analyzed. The analysis results show that the integrated brake meets the requirements of braking performances, and improves the heat recession resistance compared with the traditional friction brake.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2789
Author(s):  
Wei Wu ◽  
Yusong Gao ◽  
Zhijian Jin

Non-insulation high-temperature superconducting coils provide a much lower risk of burnout in fault/abnormal conditions, such as hot-spot quench and overcurrent. This study employs an equivalent circuit grid model, coupled with magnetic field calculation and the E–J power law of superconductors, to deeply and systematically investigate the overcurrent charging process in a double-pancake non-insulation coil. An evident saturation of the magnetic field in the axial direction of the coil was observed and verified by experiments. Experimentally, the entire process, including the behavior of the magnetic field, was consistent with the numerical results. Based on the verified model, two main points were addressed: (1) Transient current distribution inside the coil during overcurrent charging was studied. Potential quenching risks were found to be at the innermost and outermost turn near the electrodes, as well as the pancake-to-pancake connection part. (2) Magnetic field saturation, which is a unique phenomenon in non-insulation superconducting coils during overcurrent charging, was studied in detail and first quantitatively defined by a new concept “converged load factor”. Its relationship with turn-to-turn resistivity was revealed.


2008 ◽  
Vol 575-578 ◽  
pp. 1376-1381 ◽  
Author(s):  
Chao Jun Yang ◽  
Quan Wen Li ◽  
Hong Liang Ma ◽  
Sheng Fa Jiang

A new-type of solid rotor asynchronous magnetic coupling which works on the principle of electromagnetic induction is researched by ourselves. This kind of asynchronous magnetic coupling can solve the problem effectively that the permanent magnets on its inner rotor is demagnetized if its temperature is too high, because its inner rotor need not the permanent magnets. in order to study the transmission capability of the new-type magnetic coupling, its magnetic field should be analyzed. Because of its magnetic field variety, it is extremely complicated and a precision result is difficult to be got by the analytic method of the magnetic field calculation. Here the software ANSYS FEM is used to analyze its magnetic field. And some formulas were deduced and used to calculate its torque. The experimental and calculational results indicate that this design is practicable.


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