ABB Relion 670 Series Applications Manual page 96

Section 6
Wide area measurement system
Table 11:
Name
TIMESTAT
FREQ
FREQGRAD
FREQREFCHSEL
FREQREFCHERR
FREQTRIG
DFDTTRIG
MAGHIGHTRIG
MAGLOWTRIG
6.1.3.2 Reporting filters
The PMUREPORT function block implements the reporting filters designed to avoid aliasing as the
reporting frequency is lower than the sample/calculation frequency. This means, the
synchrophasor and frequency data which are included in the C37.118 synchrophasor streaming
data are filtered in order to suppress aliasing effects, as the rate of the C37.118 data is slower than
the data rate for internal processing. For this purpose, there is an anti-aliasing filter designed for
each reporting rate. The correct anti-aliasing filter will be automatically selected based on the
reporting rate and the performance class (P/M) settings. The filters are designed to attenuate all
aliasing frequencies to at least -40 dB (a gain of 0.01) at M class.
For example, when the synchrophasor measurement follows the fundamental frequency beyond
the fixed Nyquist limits in C37.118 standard, the anti-aliasing filter stopband moves with the
measured fundamental frequency. This has to be considered in connection with C37.118, where the
passband is defined relative to a fixed nominal frequency as shown in the equation 15.
F
s
f
±
0
2
IECEQUATION2418 V1 EN-US
where,
f
0
F
s
90
PMUREPORT Monitored data
Type Values (Range)
BOOLEAN
REAL
REAL
INTEGER
BOOLEAN
BOOLEAN
BOOLEAN
BOOLEAN
BOOLEAN
The synchrophasor measurement is adaptive as it follows the fundamental
frequency over a wide range despite the reporting rate.
is the nominal frequency
is the reporting rate
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Unit
1=Ready -
0=Fail
- Hz
- -
- -
0=Freq ref not -
available
1=Freq ref error
2=Freq ref
available
- -
- -
- -
- -
1MRK 511 407-UUS Rev. J
Description
Time synchronization status
Frequency
Rate of change of frequency
Frequency reference channel number
selected
Frequency reference channel error
Frequency trigger
Rate of change of frequency trigger
Magnitude high trigger
Magnitude low trigger
GUID-D39153B5-81CE-4C1F-A816-C7A4C3407048 v2
Phasor measurement unit RES670
Application manual
PID-6244-MONITOREDDATA v2
(Equation 15)