GE L60 Instruction Manual page 158

5.3 SYSTEM SETUP
AC input actual values:
The calculated parameters associated with the configured voltage and current inputs are displayed in the current and volt-
age sections of actual values. Only the phasor quantities associated with the actual AC physical input channels will be dis-
played here. All parameters contained within a configured source are displayed in the sources section of the actual values.
DISTURBANCE DETECTORS (INTERNAL):
The 50DD element is a sensitive current disturbance detector that detects any disturbance on the protected system. 50DD
5
is intended for use in conjunction with measuring elements, blocking of current based elements (to prevent maloperation as
a result of the wrong settings), and starting oscillography data capture. A disturbance detector is provided for each source.
The 50DD function responds to the changes in magnitude of the sequence currents. The disturbance detector scheme
logic is as follows:
The disturbance detector responds to the change in currents of twice the current cut-off level. The default cut-off threshold
is 0.02 pu; thus by default the disturbance detector responds to a change of 0.04 pu. The metering sensitivity setting (
UCT SETUP DISPLAY PROPERTIES
accordingly.
5-56
ACTUAL
SOURCE 1
CURRENT PHASOR
I_1
I_2
I_0
ACTUAL
SOURCE 2
CURRENT PHASOR
I_1
I_2
I_0
ACTUAL
SOURCE 6
CURRENT PHASOR
I_1
I_2
I_0
Figure 5–13: DISTURBANCE DETECTOR LOGIC DIAGRAM
CURRENT CUT-OFF LEVEL
L60 Line Phase Comparison Relay
SETTING
PRODUCT SETUP/DISPLAY
PROPERTIES/CURRENT
CUT-OFF LEVEL
_1 - _1' >2*CUT-OFF FLEXLOGIC OPERAND
I I
_2 - _2' >2*CUT-OFF OR SRC 1 50DD OP
I I
_0 - _0' >2*CUT-OFF
I I
Where ' is 2 cycles old
I
SETTING
PRODUCT SETUP/DISPLAY
PROPERTIES/CURRENT
CUT-OFF LEVEL
_1 - _1' >2*CUT-OFF FLEXLOGIC OPERAND
I I
SRC 2 50DD OP
_2 - _2' >2*CUT-OFF OR
I I
_0 - _0' >2*CUT-OFF
I I
Where ' is 2 cycles old
I
SETTING
PRODUCT SETUP/DISPLAY
PROPERTIES/CURRENT
CUT-OFF LEVEL
_1 - _1' >2*CUT-OFF FLEXLOGIC OPERAND
I I
_2 - _2' >2*CUT-OFF OR SRC 6 50DD OP
I I
_0 - _0' >2*CUT-OFF
I I
Where ' is 2 cycles old
I
827092A3.CDR
) controls the sensitivity of the disturbance detector
5 SETTINGS
PROD-
GE Multilin