The Current-Diverting FCL-A Practical Solution to Fault Current Limiting

This paper is intended to bring to the attention of the electric power industry a practical means for achieving the benefits of fault-current limitation. This proposed scheme circumvents fundamental problems which have thus far prevented the realization of adequate, reliable fault limiters at high power voltage and current ratings. Current limitation is achieved by the simultaneous actuation of two interrupters and a grounding switch. This single action limits the fault current for the first loop by diverting it to ground, then isolates the ground switch and inserts a reactor into the line to limit subsequent fault current. Employing state-of-the-art technology, this scheme can accommodate the practical range of distribution and transmission voltages and currents. It is shown that because of the inherent characteristics of this device operating in a power system, there is virtually no significant increase in the severity of duty imposed on source side transformers.