138KV cable fault detection using magneto-optic current transducers and a new digital differential relay

摘要

ComEd is installing four sets of magneto-optic current transducers on two 138KV transmission lines feeding a new 138KV to 12KV Transmission Distribution center at the transition points on either end of an underground cable portion of the lines. The MOCT system and a new microprocessor-based current differential relay will be part of a cable fault detection scheme which will cover a one-half mile long underground section of the double circuit transmission path. The scheme will inhibit automatic reclosing of the lien if it shoudl detect a fault in the section of the line which is underground.