Numerical Study on AC Loss Characteristics of REBCO Armature Windings in a 15-kW Class Fully HTS Generator

In this study, three armature structures for a fully HTS synchronous generators were proposed. The total ac loss of the straight segments of entire armature coils was studied. The ac loss was calculated in a 2-D infinite long model by using H-formulation considering
J
_c
-
B
characteristics. The proposed armature windings can be simplified to a two-slot structure for ac loss calculation due to symmetry. AC transport current and the maximum and minimum external ac fields were applied to calculate the ac loss limits for one coil cross section in each model. The proportion of the cooling power for compensating the heat generated by ac loss in the output power under a 30-A peak transport current was estimated for the proposed three structures.