Transient shielding effect of slitted electrothermal shield of superconducting generator

An electrothermal shield with direct axis directional slits is proposed for application to a superconducting alternator with quick-response excitation system. Using the finite element method combined with external circuit equations, short-circuit characteristics due to slitting effects are investigated by comparing three cases, conventional 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 the SES model are computed and then compared with those of the CES and NES models. It is expected that the superconducting alternators with SES could adopt the quick-response excitation system.<
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