Synchrocheck; Tracking Frequency - GE L90 Instruction Manual

6.3 METERING
# FREQUENCY
# SRC 1
Four identical Source menus are available. The "SRC 1" text will be replaced by whatever name was programmed by the
user for the associated source (see
The relay measures (absolute values only)
6
reactive, and apparent power. These parameters can be monitored to reduce supplier demand penalties or for statistical
metering purposes. Demand calculations are based on the measurement type selected in the
!" menu. For each quantity, the relay displays the demand over the most recent demand time interval, the maxi-
DEMAND
mum demand since the last maximum demand reset, and the time and date stamp of this maximum demand value. Maxi-
mum demand quantities can be reset to zero with the
is measured via software-implemented zero-crossing detection of an AC signal. The signal is either a
SOURCE FREQUENCY
Clarke transformation of three-phase voltages or currents, auxiliary voltage, or ground current as per source configuration
(see the
SYSTEM SETUP
final frequency measurement is passed through a validation filter that eliminates false readings due to signal distortions and
transients. If the 87L function is enabled, then dedicated 87L frequency tracking is engaged. In this case, the relay uses the
!"
METERING

TRACKING FREQUENCY

value.
QUENCY
PATH: ACTUAL VALUES

# SYNCHROCHECK 1

#
The Actual Values menu for Synchrocheck 2 is identical to that of Synchrocheck 1. If a synchrocheck function setting is
"Disabled", the corresponding actual values menu item will not be displayed.
6-16
SRC 1 DMD W:
MESSAGE
0.000
SRC 1 DMD W MAX:
MESSAGE
0.000
SRC 1 DMD W DATE:
MESSAGE
2001/07/31 16:30:07
SRC 1 DMD VAR:
MESSAGE
0.000
SRC 1 DMD VAR MAX:
MESSAGE
0.000
SRC 1 DMD VAR DATE:
MESSAGE
2001/07/31 16:30:07
SRC 1 DMD VA:
MESSAGE
0.000
SRC 1 DMD VA MAX:
MESSAGE
0.000
SRC 1 DMD VA DATE:
MESSAGE
2001/07/31 16:30:07
SRC 1 FREQUENCY:
0.00 Hz
!"
SETTINGS SYSTEM SETUP
SOURCE DEMAND
!" settings). The signal used for frequency estimation is low-pass filtered. The
POWER SYSTEM
!
TRACKING FREQUENCY
!" !"
METERING SYNCHROCHECK
SYNCHROCHECK 1 DELTA
VOLT: 0.000 V
SYNCHROCHECK 1 DELTA
MESSAGE
PHASE:
SYNCHROCHECK 1 DELTA
MESSAGE
FREQ:
L90 Line Differential Relay
W
W
var
var
VA
VA
!"
SIGNAL SOURCES
on each phase and average three phase demand for real,
!"
CLEAR RECORDS CLEAR DEMAND RECORDS
value for all computations, overriding the
!
SYNCHROCHECK 1(2)
0.0°
0.00 Hz
6 ACTUAL VALUES
).
!
SETTINGS PRODUCT SETUP
command.
SOURCE FRE-
6.3.4 SYNCHROCHECK
GE Multilin