Superconducting current limiters-some comparisons and influential parameters

Taking advantage of the recent development of very low AC loss superconducting composites, the realization of AC current limiters is now possible. This device, without conventional equivalence, is based on the ultrafast transition from the superconducting (nonresistive) state to the normal (resistive) state by overstepping the critical current density. This paper first proposes an original device consisting of a series transformer short-circuited by several superconducting coils. The theoretical advantages are given in comparison to the resistive limiter. After the description of the different modelings used for the numerical simulations, the two devices are studied in relation to the apparent propagation velocity which characterizes the resistance growth after the quench. The influence of the possible impedances connected across the superconducting coil is analyzed in terms of device performances. Finally, the impacts of high-T/sub c/ cables are addressed.<>