TY - JOUR

T1 - An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

AU - Ainslie, M D

AU - Rodriguez-Zermeno, V M

AU - Hong, Z

AU - Yuan, Weijia

AU - Flack, T J

AU - Coombs, T A

PY - 2011

Y1 - 2011

N2 - AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss in superconducting coils made from YBCO coated conductors for use in an all-superconducting electric machine. This paper presents an improved 2D finite element model for the cross-section of such coils, based on the H formulation. The model is used to calculate the transport AC loss of a racetrack-shaped coil using constant and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC Superconductivity Group's all-superconducting permanent magnet synchronous motor design. To validate the modeling results, the transport AC loss of a stator coil is measured using an electrical method based on inductive compensation by means of a variable mutual inductance. Finally, the implications of the findings on the performance of the motor are discussed.

AB - AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss in superconducting coils made from YBCO coated conductors for use in an all-superconducting electric machine. This paper presents an improved 2D finite element model for the cross-section of such coils, based on the H formulation. The model is used to calculate the transport AC loss of a racetrack-shaped coil using constant and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC Superconductivity Group's all-superconducting permanent magnet synchronous motor design. To validate the modeling results, the transport AC loss of a stator coil is measured using an electrical method based on inductive compensation by means of a variable mutual inductance. Finally, the implications of the findings on the performance of the motor are discussed.

UR - http://www.scopus.com/inward/record.url?scp=79951846715&partnerID=8YFLogxK

UR - http://dx.doi.org/10.1088/0953-2048/24/4/045005

U2 - 10.1088/0953-2048/24/4/045005

DO - 10.1088/0953-2048/24/4/045005

M3 - Article

SN - 0953-2048

VL - 24

JO - Superconductor Science and Technology

JF - Superconductor Science and Technology

IS - 4

M1 - 045005

ER -