Locating of normal transitions in a Bi2223 high temperature superconducting coil by using capacitor type voltage terminals and the active power method

It is important to locate positions of normal transitions in a high temperature superconducting (HTS) coil for identifying its design and fabrication weakness. In this paper, the authors propose a locating method by using capacitor type voltage terminals and the active power method. The former is a method to measure voltage in a HTS coil without electric contact and the latter is a method to detect the normal transitions by measuring active power dissipated in the coil. Combination of the two methods can achieve precise location of the normal transitions. The authors show usefulness of the method through experimental results for a Bi2223 HTS coil.