Open AccessDynamic loss and magnetization loss of HTS coated conductors, stacks, and coils for high-speed synchronous machines
Author(s) -
Hongye Zhang,
Philip Machura,
Kevin Kails,
Hongyi Chen,
Markus Mueller
Publication year - 2020
Publication title -
superconductor science and technology/superconductor science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.033
H-Index - 105
eISSN - 1361-6668
pISSN - 0953-2048
DOI - 10.1088/1361-6668/ab9ace
Subject(s) - electromagnetic shielding , magnetization , materials science , electrical conductor , electromagnetic coil , harmonics , skin effect , dielectric loss , nuclear magnetic resonance , mechanics , computer science , acoustics , electrical engineering , magnetic field , physics , optoelectronics , composite material , voltage , dielectric , engineering , quantum mechanics
Dynamic loss is an essential parameter to consider for the design of high temperature superconducting (HTS) synchronous machine windings. For aerospace electric propulsion systems, the fundamental frequency component and harmonics in electric machines can attain kHz level because of the high rotating speed. However, for HTS coated conductors (CC), the existing definition of dynamic loss only considers the HTS layer, the validity of which at high frequencies is questionable. Besides, the variation of dynamic loss and magnetization loss under skin effect due to high frequency is still unknown. Additionally, the influence of shielding effects among distinct turns on the dynamic loss of HTS stacks and coils remains unclear. In response to the above concerns, by use of the H -formulation based numerical multilayer modelling method which considers all layers of a CC, the frequency dependence of dynamic loss and magnetization loss of HTS CCs, stacks and coils over a wide range up to 20 kHz has been investigated. Results show that the existing definition of the dynamic region is no longer valid at kHz level, which shrinks rapidly with increasing frequency and magnetization loss plays a progressively important role due to skin effect. Meanwhile, the shielding effect in HTS stacks and coils can enhance the significance of dynamic loss. This paper clarifies the characteristics of dynamic loss and magnetization loss of HTS CCs, stacks, and coils over a wide frequency band, which can serve as a useful reference for accurate loss controlling of machine windings in future aerospace HTS propulsion systems.