Mitigation of Superconducting AC Losses in Axial Flux Synchronous Machines With Multifilament Coated Superconductors

Abstract

Fully superconducting machine typologies allow maximizing the advantages of superconductors in rotating electrical machines and might be a key in overcoming the power density limitations of current technologies. However, their realization is facing a challenge since superconductors generate non negligible AC losses when supplied by AC currents or subjected to AC fields. Deviating the magnetic field from the wide surface of the conductor and striation are proven methods to significantly reduce magnetization losses in coated conductors. However, striation is only effective when filaments are decoupled electromagnetically. Winding a copper-plated striated coated conductor spirally around a core is a novel method to decouple filaments. In this work, cables consisting of such multifilament coated conductors are applied in an axial flux synchronous machine model and their losses are compared to those of superconducting tapes with magnetic leakage flux parallel to their wide surfaces. Cables’ models are first verified by comparison with analytical and experimental results. Then, these are applied in a single slot model previously developed by the authors to analyze and compare loss results to those of single tapes carrying the same current when exposed to the same surrounding magnetic fields.