SEL-400G Advanced Generator Protection System

elements that conform to IEC 60255-149 standard.

➤ Breaker Failure Protection (50BF). The

SEL-400G provides high-speed breaker failure for

as many as four circuit breakers. The logic is

immune to subsidence current and complimented

with breaker flashover detection logic.

➤ System Backup Protection. The SEL-400G

provides phase distance (21P) elements, voltage

controlled time-overcurrent (51C) elements, and

voltage-restrained time-overcurrent (51V)

elements for system backup protection.

➤ Synchronism Check (25). The SEL-400G

provides a synchronism-check function for as

many as three breakers. The function provides

supervision for acceptable voltage window and

maximum percentage difference, maximum and

minimum allowable slip frequency, target closing

angle, and breaker closing delay.

➤ Autosynchronizer (25A). The SEL-400G provides

comprehensive automatic synchronization control

of governor and voltage regulators for as many as

three breakers through use of pulse width

modulated contact outputs.

➤ Loss of Potential (60). The SEL-400G provides

loss-of-potential (LOP) elements for the V and Z

terminals.

➤ Synchrophasors. The SEL-400G provides

synchrophasor measurement of all 18 currents and

6 voltage channels. The relay complies with IEC/

IEEE 60255-118-1:2018 (IEEE C37.118.1-2011. -2014a) and supports as many as five unique

synchrophasor data streams that are compliant with

IEEE C37.118.2-2011 via serial or Ethernet

communications ports. The relay can record

Synchrophasor data for as long as 120 seconds

based on user-settable triggers.