Development and successful testing of MCP BSCCO-2212 components for a 10 MVA resistive superconducting fault current limiter

The German government funded resistive superconducting fault current limiter project CURL 10 is based on bulk material and aims at the development of a three-phase prototype for the medium voltage level (10 kV, 10 MVA). The key element of the project is the development of suitable robust superconducting components. On the basis of the well known melt cast process (MCP) for BSCCO-2212, these are manufactured by cutting superconducting tubes to bifilar coils. At the operation temperature of 65 K a current density of 4000 A cm −2 was achieved. In order to protect the superconductor during limitation the component was equipped with an electrical shunt contacted on its entire length. Single-phase tests with nine of these components in series, corresponding to a protected load of 1.2 MVA, have been successfully accomplished and are described in detail. These tests include different types of short circuits as specified by the utilities within the project and included lightning surge loads up to 75 kV.