Thermal performance improvement of magnetic-shield superconducting fault current Limiter, by using heat-sink in its structure

Today, with increasing demand for electric power, distribution and transmission networks are expanding rapidly. With the expansion of network, the level of short-circuit currents is also increasingly rising. One of the ways that can be considered to reduce short circuit current is SFCLs. This kind of equipment in compared with other FCL has some disadvantages, such as large size (especially in inductive type), high cost, and the need for a powerful cooling system along with great benefits such as very fast performance in less than a half cycle, and they don't need any triggering circuit. Superconductors lose their superconducting behavior above a critical temperature. So, they must always work under their critical temperature. To reduce the recovery time, it is necessary to increase the power of the cooling system or a method is used to accelerate the transfer of the heat which produced by fault current in HTS. In this paper, a heat sink is designed to improve the thermal behavior of HTS material in SFCL instead of using bulk cooling systems in order to decrease the recovery time. The results show that, in addition to reducing the recovery time, the temperature distribution across the throughout HTS surface is uniform and, as a result, the disadvantages of the hotspot phenomenon will also be eliminated. Different modes of designing punched fins to the HTS cylinder located in a magnetic shield open-core superconductor limiter have been evaluated. The results suggest that with the full coverage of the HTS cylinder by an aluminum tube and placing the fins on its outer surface, the thermal performance of the magnetic shield core SFCL will be best achieved. Also, the effect of adding additional elements to the SFCL chamber is considered in terms of pressure and stress variations and the results are presented.