Title :
Static relays permit enhanced protection
Author :
Bailey, Bruce ; Jakominich, Dan
Author_Institution :
Siemens Power Transmission & Distribution, Raleigh, NC, USA
Abstract :
Multi-function multi-phase static overcurrent relays, using digital technology available today, provide basic time, (51) (51G) (51N) and instantaneous (50) (50G) (50N) three phase and ground overcurrent protection, and may offer some or all of the following additional functions: undervoltage (27); overvoltage (59); reverse phase sequence (47); negative phase sequence voltage (47N); directional overcurrent (67) (67N); frequency (81O/U); reverse interlocking trip coil monitoring; and battery monitoring. This article describes two applications that use some of the additional functions in such a relay: reverse interlocking, also using the directional overcurrent (67) function; and ground fault detection for systems utilizing high resistance grounding. The first application was installed on a 4160 volt power system which was supplied by two 5000 kVA transformers
Keywords :
earthing; fault location; overcurrent protection; power system protection; relay protection; 4160 V; battery monitoring; digital technology; directional overcurrent; enhanced protection; frequency; ground fault detection; ground overcurrent protection; high resistance grounding; multi-function multi-phase static overcurrent relays; negative phase sequence voltage; overvoltage; power system; reverse interlocking; reverse interlocking trip coil monitoring; reverse phase sequence; static relays; three phase overcurrent protection; transformers; undervoltage; Batteries; Coils; Digital relays; Electrical fault detection; Frequency; Monitoring; Power system relaying; Protection; Protective relaying; Voltage control;
Journal_Title :
Industry Applications Magazine, IEEE
DOI :
10.1109/2943.750387
