Electro-Thermal Homogenization of HTS Stacks and Roebel Cables for
Machine Applications
Abstract
This paper presents a homogenized electro-thermal model for
high-temperature superconductor (HTS) stacks made of multiple REBCO
tapes, which reduces the computational complexity of their thermal
analysis. The electromagnetic analysis is performed in both the H- and
Tâ\euro“A-formulation. An average heat capacity and an orthotropic
heat conductivity are derived for the equivalent thermal properties of
the HTS coil. The proposed homogenization method is verified to produce
the same results as the full model with an error below 5% for a range
of scenarios, including transport losses, magnetization losses, AC
frequencies from 50 to 300 Hz and a temperature range from 25 to 80 K.
Finally, the model is applied to study a permanent magnet motor with HTS
armature windings, and is verified to produce accurate results as long
as the stabilizer eddy current losses are low. Compared to the full
multilayer model, the newly proposed model allows for the use of a
significantly coarser mesh, which reduces the computation time by an
order of magnitude.