WITH the dramatically increased demand on electric
power, new power generation is being added and the
power delivery networks are being upgraded. The levels of
fault currents from events such as lightning striking a power
line, or downed trees or utility poles shorting the power lines
to ground, can increase beyond the capabilities of the existing
equipment, leaving circuit breakers in an “over-duty” condition.
Fault-current limiters (FCL) using high temperature superconductors
offer a solution to control fault-current levels on utility
distribution and transmission networks [1]–[5]. SuperPower,
Inc. and its research partners, including American Electric
Power (AEP), have been working on a three-phase program to
develop a practical SFCL to meet the needs of the utilities