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Numerical simulations on the AC loss of REBCO stacks under rotating magnetic fields

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posted on 2024-11-28, 22:25 authored by Y Wang, J Fang, T Haugan, Rodney BadcockRodney Badcock, James StoreyJames Storey, Zhenan JiangZhenan Jiang
AC loss presents a significant challenge for high-temperature superconducting (HTS) rotating machines. To date, the behaviour of total AC loss (Qtol) (with current) and magnetization loss (Qm) (without current) in a single HTS tape under rotating magnetic fields (RF) have been explored. However, a research gap remains in understanding how these findings translate to the more complex HTS windings of rotating machines. Further exploration is needed to understand the loss behaviour of more complex HTS structures, such as HTS stacks. In this work, Qtol and Qm, in the HTS stacks under RF and a perpendicular AC standing wave magnetic field are numerically investigated. Two different RF models are considered: one is the Uni-RF model, characterized by a uniform field with equal field amplitudes and phases at each position, and the other is a non-uniform field created by a rotating Halbach array, referred to as the Hal-RF model. The dependence of AC loss on parameters such as the number of tapes in the stacks, tape width (2a), and the inclination angle (α) of tapes, which refers to the angle between the normal direction of the stack and the vertical direction, have been explored. The number of tapes in the stacks ranges from 1 to 16, α ranges from 0° to 90°, and the tape width includes 4 mm and 40 mm. Additionally, different rotating field directions are also considered. Interestingly, the analytical values from Brandt and Indenbom equation for Qm of a superconducting strip (BI-strip) are close to Qm results of the stacks under the standing wave at high fields, while they are over twice as high as those in the Hal-RF model at 1 T. This suggests the BI-strip equation is not reliable for predicting Qm under RF at high fields. We also show in the Hal-RF model that different rotation directions of the field lead to varying Qm and Qtol when asymmetric Jc (B, θ) data are applied. Moreover, it has been observed that the inclination angle has no impact on Qm under uniform RF while significantly impacts both Qm and Qtol in the Hal-RF model.

Funding

CHARACTERIZING AC LOSSES OF VARIOUS ADVANCED CONDUCTORS IN THE STATORS OF ROTATING MACHINES | Funder: United States Department of the Air Force | Grant ID: FA23862214054

History

Preferred citation

Wang, Y., Fang, J., Haugan, T., Badcock, R. A., Storey, J. G. & Jiang, Z. (2024). Numerical simulations on the AC loss of REBCO stacks under rotating magnetic fields. Superconductivity, 11, 100111-100111. https://doi.org/10.1016/j.supcon.2024.100111

Journal title

Superconductivity

Volume

11

Publication date

2024-09-01

Pagination

100111-100111

Publisher

Elsevier BV

Publication status

Published

ISSN

2772-8307

eISSN

2772-8307

Article number

100111

Language

en

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