Design and Development of 15 MVA Class Fault Current Limiter for Distribution Systems

As a consequence of electric power systems growth and further interconnection, the fault current levels increase. Therefore there is the interest in devices which are able to limit fault currents. The superconducting fault current limiter (SFCL) is an innovative device able to limit the short-circuit currents to lower levels, so that no component or underrated switching equipment in the system becomes overloaded but can be operated safety. In this work, we report on design and development of a 9 kV/15 MVA-class SFCL for MV distribution system, based on 1G and 2G HTS. The project final goal is to develop a SFCL for a MV distribution system, including design, fabrication, test at a high power test facility, installation and operation in the Milan area distribution network. AC losses for different HTS winding arrangements and SFCL short-circuit simulation results for two selected network case studies are reported and discussed.