Open Source Codes for Computing the Critical Current of Superconducting Devices

TL;DR

This paper details the implementation and comparison of numerical models for predicting the critical current in high-temperature superconductor cables, emphasizing the importance of accurate material property descriptions and providing open-source tools.

Contribution

It introduces multiple open-source implementations of a static numerical model for critical current prediction in HTS cables and compares their accuracy and efficiency.

Findings

Open-source numerical models are effective for critical current prediction.

Accurate angular dependence of Jc(B) significantly impacts results.

Different programming environments vary in speed and precision.

Abstract

In order to transport sufficiently high current, high-temperature superconductor (HTS) tapes are assembled in cable structures of different forms. In such cables, the tapes are tightly packed and have a strong electromagnetic interaction. In particular, the generated self-field is quite substantial and can give an important contribution in reducing the maximum current the cable can effectively carry. In order to be able to predict the critical current of said cable structures, a static numerical model has been recently proposed. In this contribution, we present in detail the implementation of such models in different programming environments, including finite-element-based and general numerical analysis programs, both commercial an open-source. A comparison of the accuracy and calculation speed of the different implementations of the model is carried out for the case of a Roebel cable. The model is also used to evaluate the importance of choosing a very accurate description of the angular Jc(B) dependence of the superconductor as input for the material's property. The numerical codes, which are open-source, are made freely available to interested users.