Normal Zone Initiation and Propagation Characteristics of a Solid Nitrogen Cooled GdBCO Racetrack Pancake Coil

This paper presents quench test results, of both experiment and simulation, of a racetrack pancake coil wound with a GdBCO-coated conductor tape in a solid nitrogen (SN2) cooling system at 58 K. The longitudinal normal zone propagation velocities in the curved section were 2 times faster than those in the straight section. Therefore, the straight section should be protected more than the curved section when using racetrack-type, GdBCO pancake coils in large-scale rotating machines. The simulated results showed good agreement with the experimentally observed normal zone initiation times.