AC Loss Evaluation of MgB_2 Superconducting Windings Located in a Stator Core Slot with a Finite-Element Method

摘要

AC losses in stator windings of fully superconducting motors with an MgB_2 wire are numerically evaluated by means of a finite-element method using edge elements for a self-magnetic field. The physical properties of the MgB_2 wire for numerical calculations are obtained from the corresponding experiments with an existing wire. It is assumed that the voltage-current characteristics of the MgB_2 wire are given by Bean's critical-state model, in which the critical current density is independent of the local magnetic field. The influences of core slot size and turn number of windings on the AC losses are discussed quantitatively toward the optimum design of the stator winding with the MgB_2 wire.