Numerical study of the influence of flux creep and of thermal effect on dynamic behaviour of magnetic levitation systems with a high-Tcsuperconductor using control volume method

Alloui, Lotfi; Bouillault, Frédéric; Mimoune, S.M.

doi:10.1051/epjap/2009008

Cited by 24 publications

(21 citation statements)

References 19 publications

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“…It is one of the numerical methods widely used in computation of heat and fluid dynamic problems [7]. Furthermore, this method has been applied successfully to a variety of electromagnetic problems [8][9][10][11]. It uses a support space mesh based on an unstructured grid (Fig.…”

Section: Calculation Methodsmentioning

confidence: 99%

Increasing flux density by HTS shielding pellet in superconducting synchronous machine based on flux concentration

Boumaraf

Mimoune

Alloui

et al. 2014

Int J Syst Assur Eng Manag

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In this paper, we propose a solution which enhances the performance of the inductor in high-power superconducting synchronous machines based on the flux concentration. The work is done by keeping the same topology and using a high temperature superconducting shielding pellet located between the two coils of the inductor. This pellet permits to recover the magnetic field which vanishes in the medium region due to the opposite direction of the coils. We did a 3D magnetostatic field analysis using the control volume method with unstructured grid. This analysis showed that the suggested solution allowed obtaining a maximum efficiency of about 8% in the flux density. . In fact, the previous superconducting inductor has been optimized and its new geometry provides higher performance when using NbTi wires [5]. In the same way, a modification of HTS shield length should decrease the magnetic flux concentration. INDEX TERMS:To increase the power in these types of machines, several ways are proposed. The first obvious solution suggests new superconducting wires with higher current density possibility, the second one consists in a biggest inductor radius dimension and the third alternative suggests exploring a long inductor length [6].In this work, we propose an ingenious solution by using a HTS shielding pellet between the two coils of the inductor. The introduction of this pellet enhances the performance of the inductor while keeping the same geometry as in the previous topology. The inserting of the pellet has the goal to recover the magnetic field that vanishes in the medium region due to the opposite direction of coils in previous geometry. To model the magnetostatic field, we adopted in this work a three dimensional (3D) magnetostatic field analysis using the control volume method (CVM) with unstructured grid. PROPOSED DESIGNThe previous structure of the superconducting inductor is based on the flux concentration (Fig. 1). The inductor uses both low-temperature superconductors (LTS) NbTi wires and High temperature superconductors (HTS) YBCO bulk. The LTS NbTi wires create a high magnetic field through two coaxial coils fed by opposite currents. Four YBCO bulk plates are located between the two coils to screen the normal component of the magnetic field. They are used as magnetic shields, shape the flux lines and then provide a spatial magnetic field variation.The inductor configuration allows a good flux concentration between the four YBCO shielding bulk plates and increases the magnetic flux density in the air gap providing a high power density and a high electromagnetic torque. The inductor is kept stationary in order to simplify the cryogenics and minimize cold losses [5].To increase moreover the power density of the superconducting motor by increasing magnetic flux density several ways are possible. One solution suggests new

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Section: Calculation Methodsmentioning

confidence: 99%

Increasing flux density by HTS shielding pellet in superconducting synchronous machine based on flux concentration

Boumaraf

Mimoune

Alloui

et al. 2014

Int J Syst Assur Eng Manag

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“…The numerical method used in this paper is the CVM recently published [7], [13]. The CVM can be regarded as a special version of the weighted residuals method.…”

Section: B Numerical Analysis Modelmentioning

confidence: 99%

“…A 3-D numerical model based on finite-element method have to face up the numerical oscillations that affect convergence properties. Different works based on flux approaches are introduced to handle theses convergence problem [7]- [9], [13]. Unfortunately, few of them are dedicated to study the thermomagnetic system that characterizes the superconductor materials.…”

Section: Introductionmentioning

confidence: 99%

3-D Numerical Evaluation of Trapped Magnetic Field and Temperature of a Rectangular GdBaCuO Bulk Magnetized by MMPSC Method

Khene¹,

Alloui²,

Bouillault³

et al. 2015

IEEE Trans. Magn.

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International audienceIn this paper, numerical simulations of trapped field and temperature rise in a bulk superconductor during magnetization process are studied. The pulsed field magnetization method and the modified multi-pulse technique with stepwise cooling are presented. We adopt the control volume method for solving the thermomagnetic system describing the physical phenomena. The electromagnetic fields and temperature are computed because of an explicit algorithm. The results are compared with published experimental results and show a good concordance

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“…Analysis of these cases requires 3-D Finite Element Method (FEM) models [8], [9] which can become computationally expensive. Control volume techniques may also be applicable, but these also require iterative solution steps like FEM [10], [11]. Currently, there are no low-order methods that can capture the stiffness, dynamic, and hysteretic behavior induced by the translational motion.…”

Section: Introductionmentioning

confidence: 99%

Lumped-Parameter Model to Describe Dynamic Translational Interaction for High-Temperature Superconducting Bearings

Hearn

Pratap

Chen

et al. 2014

IEEE Trans. Appl. Supercond.

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Abstract-This paper discusses a lumped parameter modeling methodology to describe the dynamic vertical and translational force interaction between a bulk superconductor and levitated permanent magnet. The model is formulated to be easily incorporated into larger rigid body system models to aid design of superconducting bearings for flywheel energy storage applications. The proposed modeling technique will significantly reduce the computational expense in order to shorten the design cycle process. The validity of the proposed lumped parameter model is demonstrated by comparing results from Finite Element Method analysis and measurements of the force displacement interaction between a permanent magnet and bulk high temperature superconductor.

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Numerical study of the influence of flux creep and of thermal effect on dynamic behaviour of magnetic levitation systems with a high-T_csuperconductor using control volume method

Cited by 24 publications

References 19 publications

Increasing flux density by HTS shielding pellet in superconducting synchronous machine based on flux concentration

Increasing flux density by HTS shielding pellet in superconducting synchronous machine based on flux concentration

3-D Numerical Evaluation of Trapped Magnetic Field and Temperature of a Rectangular GdBaCuO Bulk Magnetized by MMPSC Method

Lumped-Parameter Model to Describe Dynamic Translational Interaction for High-Temperature Superconducting Bearings

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