9.9
Date Code 20171006 Instruction Manual SEL-400 Series Relays
Reporting
Oscillography
See Section 7: Metering, Monitoring, and Reports in the product-specific instruc-
tion manual, to determine the event storage capacity for any specific relay. The
relay automatically overwrites the oldest events with the newest events when the
nonvolatile storage capacity is exceeded.
Oscillography
The relay features the following types of oscillography:
➤ Raw data oscillography—effective sampling rate as fast as
8000 samples/second
➤ Event report oscillography from filtered data—either a processing
interval or 4 samples/cycle—including 20 settable analog quantities
Use high-resolution raw data oscillography to view transient conditions in the
power system. You can set the relay to report these high-resolution oscillograms
at 8000 samples/second, 4000 samples/second, 2000 samples/second, and 1000
samples/second effective sampling rates. The high-resolution raw data and travel-
ing wave data oscillograms are available as files through the use of Ymodem file
transfer and File Transfer Protocol (FTP) in the binary COMTRADE file format
output (IEEE Std C37.111-1999, Common Format for Transient Data Exchange
(COMTRADE) for Power Systems).
The filtered data oscillograms give you accurate information on the relay protec-
tion and automation processing quantities. The relay outputs filtered event
reports through a terminal or as files in ASCII format and Compressed ASCII
format, through FTP and Ymodem file transfers. Figure 9.4 shows a sample fil-
tered-data oscillogram.
Raw Data Oscillography
Raw data oscillography produces oscillograms that track power system anoma-
lies that occur outside relay digital filtering. If the relay receives signals via CT
and PT, raw data oscillography captures data with content ranging from dc to
greater than 3.0 kHz; the –3 dB point of the low-pass analog input filter is 3.0
kHz (with response rolling off at –20 dB per decade). The frequency of raw data oscil-
Figure 9.4 Sample Oscillogram
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