A silicon carbide fault current limiter for distribution systems

Increasing load densities are leading to higher fault currents that may exceed the ratings of current circuit breakers. In addition, computer-controlled equipment is more susceptible to power supply disturbances of relatively long durations. So, there is a need for a new piece of equipment which is able to interrupt fault currents before reaching their first maximum peak isolating very fast faulted sections of a distribution system. Solid-state fault current limiters (SSFCL) have been proposed as a solution to accomplish the above, and thus, as a substitute for slow-operating electromechanical circuit breakers. The design of a silicon carbide fault current limiter with high voltage blocking capability and the subsequent testing at a 15-kV test facility are addressed in this paper. The semiconductor devices of this series-connected SSFCL are custom packaged silicon carbide super gate turnoff thyristors and SiC PIN diodes. The 4.16-kV experimental tests illustrate the performance of the proposed SSFCL and demonstrate the potential for deploying them in distribution systems.