Sel 411L - Page 672

P.9.26
SEL-411L Relay Protection Manual Date Code 20151029
Monitoring and Metering
Metering
Instantaneous
Metering
Use instantaneous metering to monitor power system parameters in real time.
The relay provides these fundamental frequency readings:
➤ Fundamental frequency phase voltages and currents
➤ Phase-to-phase voltages
➤ Sequence voltages and currents
➤ Fundamental real, reactive, and apparent power
➤ Displacement power factor
You can also monitor these real-time rms quantities (with harmonics
included):
➤ RMS phase voltages and currents
➤ Real and apparent rms power
➤ True power factor
Both the fundamental and the rms-metered quantities are available for the
LINE input. The relay also provides both the fundamental and rms circuit
breaker currents for circuit breakers BK1 and BK2.
Voltages, Currents, Frequency
NOTE: After power up, automatic
restart, or a warm start, including
settings change and group switch, in
the beginning period of 20 cycles, the
10-cycle average values are initialized
with the latest calculated 1-cycle
average values.
Table 9.13 summarizes the metered voltage, current, and frequency quantities
available in the relay. The relay reports all instantaneous voltage magnitudes,
current magnitudes, and frequency as absolute value 10-cycle averages (for
example, the LINE A-phase filtered magnitude LIAFM_10c. Instantaneous
metering also reports sequence quantities referenced to A-phase. The relay
references angle measurements to positive-sequence quantities. The relay
reports angle measurements in the range of ±180.00 degrees.
MET M Display line maximum/minimum metering information
MET BKn M Display Circuit Breaker n maximum/minimum metering information
MET RM Reset line maximum/minimum metering information
MET BKn RM Reset Circuit Breaker n maximum/minimum metering information
MET D Display demand line metering information
MET RD Reset demand line metering information
MET RP Reset peak demand line metering information
MET E Display energy line metering information
MET RE Reset energy line metering information
MET SYN Display synchronism check voltage and slip angle/frequency
information
MET BAT Display dc battery monitor information (see Figure 9.14)
MET PM Display phasor measurement (synchrophasor) metering information
a
n is 1 or 2, representing Circuit Breaker 1 and Circuit Breaker 2, respectively.
Table 9.12 MET Command (Sheet 2 of 2)
Name
a
Description