Title :
Flexible inverse overcurrent relaying using a microprocessor
Author :
Kramer, Cheryl A. ; Elmore, Walter A.
Author_Institution :
Westinghouse Electr. Corp., Coral Springs, FL, USA
fDate :
4/1/1990 12:00:00 AM
Abstract :
The fundamentals of inverse time overcurrent relaying, recent changes in transformer characteristic curves, and a flexible microprocessor-based relay that has wide application possibilities are described. Insight into the process of selecting a particular time-current operating characteristic shape for a given application is provided. Guidelines are presented for the selection of a setting for an instantaneous-trip device based upon its transient reach tendencies. It is concluded that the availability of a microprocessor-based inverse time overcurrent relay that has selectable characteristics built in will greatly relieve the application difficulties that have been associated historically with their fixed-characteristic electrochemical counterparts
Keywords :
microcomputer applications; overcurrent protection; power system computer control; power system protection; relay protection; instantaneous-trip device; inverse overcurrent relaying; microprocessor; overcurrent protection; power system computer control; power system protection; relay protection; time-current operating characteristic; transformer characteristic curves; transient reach; Circuit faults; Current transformers; Digital relays; Microprocessors; Power system relaying; Power system transients; Protection; Protective relaying; Shape; Springs;
Journal_Title :
Power Delivery, IEEE Transactions on
