AREVA’s Transmission and Distribution division and Bruker Energy & Supercon Technologies have successfully designed, built and tested a single module of a 13 MVA (2000 A, 6.4 kV) single-phase, shielded-type inductive superconducting fault current limiter at the AREVA T&D Technology Centre in Stafford, UK. The design uses a proprietary cryogenic module incorporating BEST’s second-generation high-temperature superconductors.
Increasing demand for electricity and the restructuring of the power transmission system resulting from deregulation and the increased level of distributed and renewable energy generation can lead to fault current levels above the capability of existing switchgear. A viable solution is to install a current-limiting device that is self-triggering, rapidly activated within a few milliseconds, and failsafe.
As a result of the tests in Stafford, the following conclusions were drawn:
- The SFCL module limited a prospective 68.5 kA peak fault to 9 kA peak in five milliseconds (¼ cycle)
- Fault current after five cycles (before circuit breaker opening) was reduced by a factor of 10
- The SFCL exhibits fast recovery after a short circuit fault (less than 200 milliseconds) and is expected to withstand a large number of limitation sequences