Study on Quench Protection of Coil Wound of Bi/Ag-Sheathed Wire

Sure quench protection of HTS coils is essential for their sustainable operations in their real applications to HTS power devices. The authors investigate conditions to safely protect HTS coils from quench damages by a detect-and-dump-type active method. In the previous work, the safe area in the V
_qs
versus τ plane was identified by experiment using test coils wound of Bi/Ag-sheathed wires, where V
_qs
is the quench detection voltage, and τ is the decay time constant of the coil current in the active protection method. In this work, the safe area is obtained by numerical calculation, making a simulation model of a winding pack of a coil wound of Bi/Ag-sheathed wires. The analytical results well agree with those of the experimental results, and it is shown analytically that condition to safely protect a coils wound of Bi/Ag-sheathed wires from a quench damage can be analytically predicted.