H.10
SEL-787 Relay Instruction Manual Date Code 20150130
Synchrophasors
View Synchrophasors Using the MET PM Command
The Time Synchronization Relay Word bits in Table H.8 indicate the present
status of the timekeeping function of the SEL-787.
View Synchrophasors Using the MET PM Command
The MET PM serial port ASCII command may be used to view the SEL-787
synchrophasor measurements. See MET Command (Metering Data) on
page 7.31 for general information on the MET command.
There are multiple ways to use the MET PM command:
➤ As a test tool, to verify connections, phase rotation, and scaling
➤ As an analytical tool, to capture synchrophasor data at an exact
time, in order to compare it with similar data captured in other
phasor measurement unit(s) at the same time
➤ As a method of periodically gathering synchrophasor data
through a communications processor
The MET PM command displays the same set of analog synchrophasor
information, regardless of the Global settings PHDATAV, PHDATAI, and
PHCURR. The MET PM command can function even when no serial ports
are sending synchrophasor data—it is unaffected by serial port setting
PROTO.
The MET PM command will only operate when the SEL-787 is in the IRIG
timekeeping mode, as indicated by Relay Word bit TSOK = logical 1.
Figure H.4 shows a sample MET PM command response. The synchrophasor
data are also available via the HMI > Meter PM menu in
ACSELERATOR
QuickSet, and has a similar format to Figure H.4.
The MET PM time command can be used to direct the SEL-787 to display the
synchrophasor for an exact specified time, in 24-hour format. For example,
entering the command MET PM 14:14:12 will result in a response similar to
Figure H.4 occurring just after 14:14:12, with the time stamp 14:14:12.000.
Table H.7 Synchrophasor Trigger Relay Word Bits
Name Description
PMTRIG Trigger (SELOGIC)
TREA4 Trigger Reason Bit 4 (SEL
OGIC)
TREA3 Trigger Reason Bit 3 (SEL
OGIC)
TREA2 Trigger Reason Bit 2 (SEL
OGIC)
TREA1 Trigger Reason Bit 1 (SEL
OGIC)
Table H.8 Time Synchronization Relay Word Bits
Name Description
IRIGOK Asserts while relay time is based on IRIG-B time source.
TSOK Time Synchronization OK. Asserts while time is based on an IRIG-B
time source of sufficient accuracy for synchrophasor measurement.
PMDOK Phasor Measurement Data OK. Asserts when the SEL-787 is enabled
and synchrophasors are enabled (Global setting EPMU := Y).
NOTE: In order to have the MET PM
xx:yy:zz response transmitted from a
serial port, the corresponding port
must have the AUTO setting set to
YES (Y). Also note that the MET PM
response is not available on the
Ethernet port.
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