Qualitative Simulation of the Thermal and Electrical Normal-Zone Transition of 2G-HTS Solenoidal Magnets: Mathematical Model and Example

The ongoing development of a semi-analytical/numerical model aims at studying the qualitative thermal and electrical behavior of 2G-HTS solenoidal magnets under loss of superconducting state for both persistent and driven current modes. The mathematical transient model is based on a Runge-Kutta scheme which includes an adaptative time step to solve simultaneously heat balance and electric equations. Brent's method was used to determine the fraction of currents in the stabilizing layer during current sharing. In addition, the model implements the dependency of current density and material properties upon changes of temperature and magnetic flux density experienced by the superconducting winding during normal-zone transition. A parametric case study is presented for which striking voltage profiles are obtained which may render the detection of localized normal-zone transition a complicated task.