Sel SEL-421 - Synchrophasor Relay Word Bits; Synchrophasor Trigger Relay Word Bits; Time Synchronization Relay Word Bits; Synchrophasor Client Status Bits

R.7.19
Date Code 20111215 Reference Manual SEL-421 Relay
Synchrophasors
Synchrophasor Relay Word Bits
Synchrophasor Relay Word Bits
Tab le 7.9 and Tab le 7.10 list the SEL-421 Relay Word bits that are related to
synchrophasor measurement.
The Synchrophasor Trigger Relay Word bits in Table 7.9 follow the state of
the SEL
OGIC control equations of the same name, listed at the bottom of
Tab le 7.1. These Relay Word bits are included in the IEEE C37.118
synchrophasor data frame STAT field. See Table 7.7 for standard definitions
for these settings.
The Time Synchronization Relay Word bits in Table 7.10 indicate the present
status of the high-accuracy timekeeping function of the SEL-421. See
Configuring High-Accuracy Timekeeping on page U.4.71.
When using the relay as a synchrophasor client, the Relay Word bits in
Tab le 7.11 indicate the state of the synchronization.
Table 7.9 Synchrophasor Trigger Relay Word Bits
Name Description
PMTRIG Trigger (SELOGIC Equation).
TREA4 Trigger Reason Bit 4 (SELOGIC Equation)
TREA3 Trigger Reason Bit 3 (SEL
OGIC Equation)
TREA2 Trigger Reason Bit 2 (SEL
OGIC Equation)
TREA1 Trigger Reason Bit 1 (SEL
OGIC Equation)
Table 7.10 Time Synchronization Relay Word Bits
Name Description
TIRIG Asserts while relay time is based on IRIG-B time source.
TSOK Time Synchronization OK. Asserts while time is based on high-accu-
racy IRIG-B time source (HIRIG mode) of sufficient accuracy for syn-
chrophasor measurement.
PMDOK Phasor Measurement Data OK. Asserts when the SEL-421 is enabled
and synchrophasors are enabled (Global setting EPMU := Y).
Table 7.11 Synchrophasor Client Status Bits (Sheet 1 of 2)
Name Description
RTCENA Asserts for one processing interval when a valid message is received on
channel A
RTCENB Asserts for one processing interval when a valid message is received on
channel B
RTCROKA Asserts for one processing interval when data is aligned for channel A.
Use this bit to condition usage of the channel A data.
RTCROKB Asserts for one processing interval when data is aligned for channel B.
Use this bit to condition usage of the channel B data.
RTCROK Asserts for one processing interval when data for all enabled channels are
aligned. Use this bit to condition general usage of the aligned synchropha-
sor data.
RTCDLYA This bit is asserted when the last received valid message on channel A is
older than MRTCDLY.