Shielding currents in multifilament coated conductors wound into pancake coils and layer-wound coils

Abstract

The effect of multifilament coated conductors on reducing shielding currents was studied by numerical electromagnetic field analyses. We compared the behaviours of the shielding currents in stacked double pancake coils and layer-wound solenoid coils (SLCs) wound with the following conductors: a monofilament coated conductor, a copper-plated two-filament coated conductor, and an insulated two-filament coated conductor. Shielding-current-induced fields (SCIFs) in the layer-wound SLCs wound with copper-plated two-filament coated conductors decay more rapidly than in stacked double pancake coils wound with copper-plated two-filament coated conductors. In addition, we examined the behaviour of the shielding currents in the coils with and without normal metal terminals. The normal metal terminals made the decay time constants of the SCIFs in pancake coils longer, while the decay time constants of SCIFs did not change notably in the layer-wound SLCs with and without normal metal terminals.