A temperature-dependent multilayer model for direct current carrying HTS coated-conductors under perpendicular AC magnetic fields

Abstract

When a type II superconductor carrying a direct current is subjected to a perpendicular oscillating magnetic field, a direct current (DC) voltage will appear. This voltage can either result from dynamic resistance effect or from flux flow effect, or both. The temperature variation in the superconductor plays an important role in the nature of the voltage, and there has been little study of this so far. This paper presents and experimentally verifies a 2D temperature-dependent multilayer model of the second generation (2G) high temperature superconducting (HTS) coated conductors (CC), which is based on H-formulation and a general heat transfer equation. The model has coupled the electromagnetic and thermal physics, and it can simulate the behavior of 2G HTS coated conductors in various working conditions where the temperature rise has a significant impact. Representative electromagnetic phenomena such as the dynamic resistance effect and the flux flow effect, and thermal behavior like quench and recovery have been simulated. This thermal-coupled model is a powerful tool to study the thermal-electromagnetic behaviors of 2G HTS coated conductors in different working conditions, especially when the impact of temperature rise is important. This multilayer model is also very useful in analyzing the impact of different layers in the 2G HTS CCs, especially the metal stabilizer layers. It has been proven to be a very powerful tool to help understand more complicated characteristics in the CCs which could not be accurately measured or simulated by previous numerical models. The work is indicative and very useful in designing ac magnetic field controlled persistent current switches and flux pumps, in terms of increasing the off-state resistance, analyzing different sources of losses, minimizing detrimental losses, and enhancing the safety and stability.

Total loss measurement and simulation in a REBCO coated conductor carrying DC current in perpendicular AC magnetic field at various temperatures

“…Higher magnetization loss in the superconductor layer and eddy current loss in the stabilizer layer at higher frequency may lead to more local heat in coated conductors. Hence, a coupled loss-thermal model in a multilayer-structured coated conductor is needed to thoroughly study this frequency dependence [41,42]. 2 , versus the applied perpendicular magnetic field, µ 0 H m , at different frequencies at 77 K, 70 K and 65 K. The normalized Q m0 /(µ 0 H m ) 2 values at different frequencies almost come into a common curve at each temperature, except a very small data disagreement at high magnetic fields.…”

Time-Domain Protection of Superconducting Cables Based on Artificial Intelligence Classifiers

“…The copper stabilizer layers along with the copper former provide an alternative parallel conducting path for transient current during the quenching. The effect of buffer layer is expected to be negligible and thus has not been considered in the model [25], [26]. Polypropylene Laminated Paper (PPLP) was applied on the HTS tapes and utilized as electric insulation, while a cryostat contains subcooled LN 2 at 65 − 70K was considered to keep SC in superconducting state.…”

Физические Принципы Создания Магнитолевитационных Систем На Основе Высокотемпературных Сверхпроводящих Композитов Второго Поколения (Обзор)

“…Такое упрощение может быть выполнено либо как рассмотрение нескольких основных слоев лент (как правило, слои меди, серебра, ВСТП и подложки) [79][80][81], либо как представление ВТСП-лент в виде тонких объемных ВТСП с инженерным критическим током [82,83].…”