Sel 411L - Metering; Table 9.12 MET Command

P.9.25
Date Code 20151029 Protection Manual SEL-411L Relay
Monitoring and Metering
Metering
Metering
The relay provides five metering modes for measuring power system
operations.
➤ Instantaneous Metering on page P.9.26
➤ Maximum/Minimum Metering on page P.9.30
➤ Demand Metering on page P.9.32
➤ Energy Metering on page P.9.36
➤ Time-Synchronized Metering on page P.9.37
➤ Differential Metering on page P.9.37
Monitor present power system operating conditions with instantaneous
metering. Maximum/Minimum metering displays the largest and smallest
system deviations since the last reset. Demand metering includes either
thermal or rolling analyses of the power system and peak demand metering.
Energy metering displays the megawatt-hours imported, megawatt-hours
exported, and total megawatt-hours. Time-synchronized metering displays the
line voltage and current synchrophasors. Differential metering displays
differential metering quantities.
The relay processes three sets of current quantities: LINE, BK1, and BK2
(when configured for two circuit breakers). In one configuration using two
circuit breakers, Terminal W is usually connected as BK1, and Terminal X is
generally connected as BK2. The line voltage from Terminal Y (VY)
(=A, B, C) provides the voltage quantities for LINE. See Current and Voltage
Source Selection on page P.3.106 for more information on configuring the
relay inputs.
Use the MET command to access the metering functions. Issuing the MET
command with no options returns the fundamental frequency measurement
quantities listed in Table 9.13. The MET command followed by a number,
MET k, specifies the number of times the command will repeat (k can range
from 1–32767). This is useful for troubleshooting or investigating
uncharacteristic power system conditions. With other command options, you
can view currents from either circuit breaker. For example, you can monitor
the fundamental currents on Circuit Breaker 1 or Circuit Breaker 2 by entering
MET BK1 or MET BK2, respectively. Additionally, the MET PM command
provides time-synchronized phasor measurements at a specific time, e.g.,
MET PM 12:00:00.
Table 9.12 lists MET command variants for instantaneous,
maximum/minimum, differential, demand, and energy metering. Other MET
command options are for viewing protection and automation variables; analog
values from M
IRRORED BITS
®
communications; and synchronism check.
Table 9.12 MET Command (Sheet 1 of 2)
Name
a
Description
MET Display fundamental line metering information
MET DIF Display differential metering quantities
MET BKn Display fundamental Circuit Breaker n metering information
MET RMS Display rms line metering information
MET BKn RMS Display rms Circuit Breaker n metering information