A self-consistent model for estimating the critical current of superconducting devices

Abstract

Nowadays, there is growing interest in using superconducting wires or tapes for the design and manufacture of devices such as cables, coils, rotating machinery, transformers and fault current limiters among others. Their high current capacity has made them the candidates of choice for manufacturing compact and light cables and coils that can be used in the large scale power applications described above. However, the performance of these cables and coils is limited by their critical current, which is determined by several factors, including the conductor's material properties and the geometric layout of the device itself. In this work we present a selfconsistent model for estimating the critical current of superconducting devices. This is of large importance when the operating conditions are such that the self-field produced by the current is comparable to the overall background field. The model is based on the asymptotic limit when time approaches infinity of Faraday's equation written in terms of the magnetic vector potential. It uses a continuous − relationship and takes the angular dependence of the critical current density on the magnetic flux density into account. The proposed model is used to estimate the critical current of superconducting devices such as cables, coils, and coils made of transposed cables with very high accuracy. The high computing speed of this model makes it an ideal candidate for design optimization.

Precision Modeling: Application of Metaheuristics on Current–Voltage Curves of Superconducting Films

“…For instance, a formal, self-consistent, model was presented for estimating critical current of superconducting devices [16]. The authors admitted that an array of antidots based thin film was very difficult to model mathematically.…”

Modeling of screening currents in coated conductor magnets containing up to 40000 turns

“…We take the critical current of the whole coil as that of the weakest turn. Comparing to other methods [31][32][33], the method in this article takes the precise magnetization currents into account. In addition, it allows to calculate the coil DC currentvoltage curve with non-uniform power-law exponent, n, and n(B, θ).…”

Effect of Self-field and Loosening of Stacked Superconducting Tapes on Critical Current of a Single Pancake Coil

“…Moreover, the effect of neighboring tapes or coils has not been considered in the general information catalogue as the I c can vary depending on the temperature and type of engineering applications. Researchers have done studies where they have considered the effect of self-field for estimating the critical current of the superconducting tape [14][21] [22]. Most of these studies consider cables with low aspect ratios or having small circular cross-sectional area.…”

“…Most of these studies consider cables with low aspect ratios or having small circular cross-sectional area. Few studies have been performed where cable consisting superconducting tapes with high aspect ratios where critical current of Roebel cables (used in transformer windings) have been estimated [14] [22]. These models have provided fair results however, they need comparative and iterative processes to evaluate the I c and there is a need to consider uniform current distribution within each superconductor.…”