Analysis of a Switched Impedance Transformer-Type Nonsuperconducting Fault Current Limiter

This paper proposes a nonsuperconducting fault current limiter (NSFCL) topology and control strategy. The switched impedance transformer-type NSFCL topology is optimized to protect against short transients and to work in conjunction with other fuses or circuit breakers, hence has the merits of being simple, low cost, and compact. A prototype has been designed and built for a three-phase 600-V_RMS,L-L system. It has been tested in a UL-certified high-power test lab with 5-A normal current and 100-kA potential fault current.