Quench protection system for two-layer superconducting coils by an active power method

Abstract When the quench occurs in the superconducting coil, the excessive joule heating in the normal region may damage the coil. It is necessary to detect the quench in the coil as soon as possible and discharge the magnetic energy stored in the coil. We have presented a quench protection system based on the active power method which detects a quench regardless of the self-inductive and mutual-inductive voltage for multi-layer superconducting coils. In this paper, the usefulness of the developed system is confirmed for two-layer superconducting coils wound with Bi 2 Sr 2 Ca 2 Cu 3 O x HTS tapes.