P.8.5
Date Code 20151029 Protection Manual SEL-411L Relay
Oscillography, Events, and SER
Duration of Data Captures and Event Reports
generate another event report later in that same continuously
occurring fault (such as an overcurrent situation with the R_TRIG
51S01 element).
In the example factory default ER SEL
OGIC control equation, if the
Z3G element remains asserted for the duration of the ground fault,
the rising-edge operator, R_TRIG, in front of Z3G causes ER to assert
for only one processing interval (a 1/8-cycle pulse). Other elements in
the ER SEL
OGIC control equation can trigger event reports while the
Z3G element remains asserted throughout the fault duration.
You can also use the falling-edge operator, F_TRIG, to initiate data captures.
EXAMPLE 8.2 Including PUL Command Triggering in the ER
SELOGIC Control Equation
This example shows you how to add the effect of the PUL command to
emulate previous SEL relays. The relay asserts Relay Word bit,
TESTPUL, when any output is pulsed via the PUL command.
Program the Group settings SEL
OGIC control equation ER as follows:
ER := R_TRIG Z2P OR R_TRIG Z2G OR R_TRIG 51S01 OR R_TRIG Z3P OR
R_TRIG Z3G OR TESTPUL
Event Report Trigger Equation
(SEL
OGIC Equation)
TRI (Trigger Event
Report) Command
Use the TRI command from any communications port to trigger the relay to
begin recording high-resolution raw data, traveling wave data, and event
report data. When testing with the TRI command, you can gain information
on power system operating conditions that occur immediately after you issue
the TRI command.
Duration of Data Captures and Event Reports
The relay stores unfiltered, high-resolution raw data (sampled at either 8 kHz,
4 kHz, 2 kHz or 1 kHz), filtered event reports (available at both 1/4 and 1/8 per
power system cycle), and traveling wave data (1.5625 MHz). The number of
stored high-resolution raw data captures and event reports is a function of the
amount of data contained in each capture. You can configure the relay to
record long data captures at high sampling rates, although this reduces the
total number of stored events you can retrieve from the relay. The relay stores
at least 20 traveling wave reports.
To use the data capture functions, select the effective sampling rate and data
capture times. Relay setting SRATE, listed in Table 8.1, determines the
number of data points the relay records per second. You can set SRATE to
8 kHz, 4 kHz, 2 kHz, and 1 kHz. The effective sampling rate (SRATE) and the
event report length (LER) are related as follows:
➤ 8 kHz sampling—3.00 seconds total event report
➤ 4 kHz sampling—6.00 seconds total event report
➤ 2 kHz sampling—9.00 seconds total event report
➤ 1 kHz sampling—12.00 seconds total event report
The length of the data capture/event report (setting LER) and the pretrigger or
prefault time (setting PRE) are related, as shown in Figure 8.2. The LER
setting is the overall length of the event report data capture; the PRE setting
determines the time reserved in the LER period when the relay records
pretrigger (prefault) data. Typically, you set the PRE time to 20 percent of the
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