AC loss calculation in coated conductor coils with a large number of turns

TL;DR

This paper presents a new method for accurately calculating AC loss in large-turn superconducting coils by accounting for magnetization currents, which are often neglected but significant in coils with thousands of turns.

Contribution

The authors develop a method to precisely compute AC loss in coils with many turns, considering magnetization currents, improving upon previous assumptions.

Findings

Magnetization currents significantly affect AC loss in large-turn coils.

The method accurately predicts current density and AC loss in coils with up to 6400 turns.

Magnetization effects cannot be neglected in large superconducting coil designs.

Abstract

For superconducting coils with many turns, it is widely believed that the magnetic field from magnetization currents is negligible compared to the one generated by the whole coil. This article shows that this is not true for coils with a considerably large number of turns (up to thousands). We introduce a method to accurately calculate the AC loss in coils with virtually any number of turns that takes the magnetization currents into account. The current density and AC loss is analyzed for two windings made of coated conductor consisting of 32 pancake coils totaling 768 and 6400 turns, respectively.