Reporting Filters - ABB RES670 Applications Manual

1MRK 511 407-UEN C
6.1.3.2
Phasor measurement unit RES670 2.2 IEC
Application manual
Name Type
FREQREFCHSEL INTEGER
FREQREFCHERR BOOLEAN
FREQTRIG BOOLEAN
DFDTTRIG BOOLEAN
MAGHIGHTRIG BOOLEAN
MAGLOWTRIG BOOLEAN

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.
The synchrophasor measurement is adaptive as it follows the
fundamental frequency over a wide range despite the reporting rate.
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 12.
F
s
f
±
0
2
IECEQUATION2418 V1 EN-US
where,
f is the nominal frequency
0
F is the reporting rate
s
Wide area measurement system
Values (Range) Unit
- -
0=Freq ref not -
available
1=Freq ref error
2=Freq ref
available
- -
- -
- -
- -
Section 6
Description
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
(Equation 12)
93