Bruker Energy & Supercon Technologies, Inc. and Schneider Electric Sachsenwerk GmbH have announced the successful completion of a major milestone in the development of a novel shielded, inductive superconducting fault current limiter (iSFCL), which is to begin field test operations in the Stadtwerke Augsburg (Germany) grid in 2013.

Testing of a subscale device under expected operating conditions was performed at the Institute for High-Voltage Engineering and Electrical Energy Systems of the University of Braunschweig, a German research institute in the field of high-voltage and power systems engineering. This device implements the same concept that is expected to be used in the full-size iSFCL system and uses BEST’s 40 mm-wide second generation (2G) high temperature superconductors (HTS), specifically designed for application in fault current limiters.

During the tests in Braunschweig, the device functioned as predicted in more than 100 triggered short-circuits. Due to the novel design of the superconducting modules, the system withstood fault durations of up to 500 milliseconds (ms), believed to be the longest withstand time reported worldwide with HTS coated conductors. Additionally, these results validated the performance parameters predicted by computer models, thus enabling extrapolation to other grid topologies and requirements.

“The positive results from these tests have further strengthened our confidence in the success of this project and the superior performance and market potential of the iSFCL design,” said Hans-Udo Klein, Senior Vice President for Business Development of BEST. “We now expect a performance and safety test of the full-size single-phase prototype later this year as the final gate for our iSFCL product development before field tests and application in the Augsburg grid next year.”

Fault current limiters are devices that protect electrical equipment in the transmission and distribution infrastructure from damaging power surges caused by fault currents arising from short circuits, power generation disturbances and lightning strikes.

The novel, proprietary iSFCL design uses HTS technology, enabling self-activation at extremely fast response times (less than 5 ms) and automatic recovery after a fault situation.

The medium-voltage iSFCL project, funded by the German Federal Ministry of Economics and Technology (Bundesministerium für Wirtschaft und Technologie, or BMWi), is a collaboration of the partners BEST, Schneider Electric Sachsenwerk GmbH, and Stadtwerke Augsburg Energie GmbH – a utility capable of providing a long-term testing environment for the iSFCL– and is based on the partners’ specific competencies. This includes BEST’s 2G HTS tapes as well as modules and know-how in superconducting devices, along with Schneider Electric's experience in designing electrical grid equipment such as transformers and their in-depth knowledge of the electric transmission and distribution markets.