Reduced Order Hysteretic Magnetization Model for Composite Superconductors

TL;DR

This paper introduces the Reduced Order Hysteretic Magnetization (ROHM) model for composite superconductors, enabling efficient simulation of magnetization and power loss without detailed current calculations, applicable across various frequencies and amplitudes.

Contribution

The paper presents a novel reduced order model that simplifies the simulation of composite superconductors' magnetic response, including hysteresis and dynamic effects, with efficient parameter determination.

Findings

ROHM model accurately reproduces hysteresis in superconductors.

Model significantly reduces computational effort in large-scale simulations.

Effective across a wide range of excitation frequencies and amplitudes.

Abstract

In this paper, we propose the Reduced Order Hysteretic Magnetization (ROHM) model to describe the magnetization and instantaneous power loss of composite superconductors subject to time-varying magnetic fields. Once the parameters of the ROHM model are fixed based on reference simulations, it allows to directly compute the macroscopic response of composite superconductors without the need to solve the detailed current density distribution. It can then be used as part of a homogenization method in large-scale superconducting models to significantly reduce the computational effort compared to detailed simulations. In this contribution, we focus on the case of a strand with twisted superconducting filaments subject to a time-varying transverse magnetic field. We propose two variations of the ROHM model: (i) a rate-independent model that reproduces hysteresis in the filaments, and (ii) a rate-dependent model that generalizes the first level by also reproducing dynamic effects due to coupling and eddy currents. We then describe the implementation and inclusion of the ROHM model in a finite element framework, discuss how to deduce the model parameters, and finally demonstrate the capabilities of the approach in terms of accuracy and efficiency over a wide range of excitation frequencies and amplitudes.