R.7.15
Date Code 20111215 Reference Manual SEL-421 Relay
Synchrophasors
Settings for Synchrophasors
PHNR
Selects the numeric representation of voltage and current phasor data in the
synchrophasor data stream.
This setting is one of eight settings that determine the minimum port SPEED
necessary to support the synchrophasor data packet rate and size—see
Communications Bandwidth on page R.7.26 for detailed information.
The choices for this setting depend on synchrophasor processor requirements.
Setting PHNR := I sends each voltage and/or current synchrophasor as 2 two-
byte integer values. In this representation, synchrophasor current
measurements have an upper limit of 7 • I
nom
, where I
nom
= 1 A or 5 A,
depending on the current input rating—see Secondary Circuits on page U.2.4.
Setting PHNR := F sends each voltage and/or current synchrophasor as 2 four-
byte floating-point values.
The PHFMT setting determines the format of the data.
PHFMT
Selects the phasor representation of voltage and current phasor data in the
synchrophasor data stream.
The choices for this setting depend on synchrophasor processor requirements.
Setting PHFMT := R (rectangular) sends each voltage and/or current
synchrophasor as a pair of signed real and imaginary values.
Setting PHFMT := P (polar) sends each voltage and/or current synchrophasor
as a magnitude and angle pair. The angle is in radians when PHNR := F, and in
radians • 10
4
when PHNR := I. The range is as follows:
– < angle <= .
In both the rectangular and polar representations, the values are scaled in rms
(root mean square) units. For example, a synchrophasor with a magnitude of
1.0 at an angle of -30 degrees will have a real component of 0.866, and an
imaginary component of -0.500. See Synchrophasor Measurement on
page R.7.6 for a sample conversion between polar and rectangular
coordinates.
FNR
Selects the numeric representation of the two frequency values in the
synchrophasor data stream.
This setting is one of eight settings that determine the minimum port SPEED
necessary to support the synchrophasor data packet rate and size—see
Communications Bandwidth on page R.7.26 for detailed information.
The choices for this setting depend on synchrophasor processor requirements.
Setting FNR := I sends the frequency data as a difference from nominal
frequency, NFREQ, with the following formula:
(FREQ
measured
– NFREQ) • 1000,
represented as a signed, two-byte value.
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