Analytical Modeling of an Inductor in a Magnetic Circuit for Pulsed Field Magnetization of HTS Bulks

Abstract

The development of bulk magnets based on REBCO type superconductors that can generate up to 17 T requires the implementation of a magnetization system, sometimes pulsed. Therefore, at least one coil around the High Temperature Superconducting (HTS) bulk is required. In this paper, we suggest an analytical approach in order to assess the magnetic vector potential and to compute the inductance of a coil having a rectangular crosssection and concentric with a magnetic circuit including an air-gap. On a proposed geometry, analytical results are compared with those obtained by using Finite Element Analysis (FEA). The gained analytical expressions give accurate results with an error less than 1% on the inductance value of the coil. The induced current density and trapped magnetic field in a HTS bulk during a Pulsed Field Magnetization (PFM) are also calculated using the proposed analytical expressions of the magnetic vector potential combined with an integral method. The achieved results show a remarkable match with those obtained with COMSOL.

2-D Numerical Modeling of a Bulk HTS Magnetization Based on <bold>H</bold> Formulation Coupled With Electrical Circuit

“…It corresponds to the lowest value of peak current of 4.4 kA and a time constant of 0.5 ms. It can be mentioned here that in [6], the authors proposed an analytic expression of the inductance of a magnetizing coil in its environment, including an iron core. Taking into account that the bulk region is a perfect diamagnetic material leads to reach the other limit of the PFM process.…”

“…In this paper, we focus on the modeling of a PFM process of an HTS bulk using a coil coupled with an electrical circuit. Most of the publications do not consider the coupling between the coil and the magnetizer in H formulation [6]- [8], what in our opinion can lead to discrepancies in the estimation of the trapped magnetic field in HTS bulk. Our model is based on the H formulation implemented using the PDE module and the global equation module in COMSOL Multiphysics 5.2a.…”

Magnetic Force Calculation between Magnets and Coils

“…In region IV: Now, using the boundary conditions, the value of the coefficients can be determined. The continuity of A and the tangential component of the magnetic flux density (Equation (5)) exist between the two regions, and the tangential component of the magnetic flux density at the core boundary is zero [17,18]. Thus, 1 , , , , , ,…”

Numerical modelling of HTS tapes under arbitrary external field and transport current via integral method: review and application to electrical machines *

“…The method is much faster than the H and T-A formulations implemented in COMSOL, as shown in [14]. Elbaa et al [17] used the integral method to calculate current distribution in an HTS bulk that was magnetised by an external coil. The external field applied to the bulk, which was created by an external coil and was nonuniform in space, was calculated analytically.…”