Design and development of a 15 kV, 20 kA HTS fault current limiter

A 15 kV class high temperature superconducting fault current limiter was developed as part of a Department of Energy Superconductivity Partnership Initiative (SPI) Phase II effort. This is an inductive/electronic fault current limiter (FCL) that can double as a fast sub-cycle solid state breaker. The said device was shipped to Southern California Edison (SCE) Center Substation at Norwalk, CA from General Atomics on June 15, 1999. Preliminary high voltage and high current testing was conducted. The pre-commercial FCL unit houses three of the world's largest Bi-2223 coils (solenoids each with an outside diameter of 1 m and a coil length of 0.75 m), collaborated by GA and IGC. These coils will operate at 35 K and be able to carry a continuous DC current of 2000 A as well as an AC pulsed current of 9000 A. Detailed specification of the FCL device and a brief description of its various subsystems will be given. Finally, test results at Center Substation are summarized and future work outlined. This Phase II FCL device is important as it has the potential to become the first major commercial product for HTS power utility application.