Transient shielding effect of slitted electrothermal shield of superconducting generator

In this paper, an electrothermal shield with direct axis directional slits is proposed for the purpose of applying to the superconducting alternator with quick response excitation system. Using FEM combined with external circuit equations, short circuit characteristics due to slitting effects are investigated by comparing three cases which are full electrothermal shield (CES), slitted electrothermal shield (SES) and no electrothermal shield (NES) models under three phase fault and line to line fault, respectively. The field current variations, flux densities in the vicinity of superconducting field winding, and the eddy currents of SES model are computed and then compared with those of CES and NES models. It is expected that SCG with SES could adopt quick response excitation system