Abstract
This paper describes experimental results of investigations on electrical and mechanical characteristics of armature coil bars to develop the insulation and cooling structure of double transposed conductors for 70 MW class superconducting generators. Four kinds of bar strands consisted of transposed small rectangular wires with different insulation structure and short armature coil bar samples with those strands were trially produced. Electrical and mechanical characteristic tests verified that epoxy resin impregnated single fiber glass cover insulation on a polyamide-imide resin coating was most available for armature coils of air gap windings, and this structure had a sufficiently high durability for its use in 70 MW class machines.
