GE D30 Instruction Manual page 153

5 SETTINGS
User selection of AC parameters for comparator elements:
CT/VT modules automatically calculate all current and voltage parameters from the available inputs. Users must select the
specific input parameters to be measured by every element in the relevant settings menu. The internal design of the ele-
ment specifies which type of parameter to use and provides a setting for source selection. In elements where the parameter
may be either fundamental or RMS magnitude, such as phase time overcurrent, two settings are provided. One setting
specifies the source, the second setting selects between fundamental phasor and RMS.
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
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.
GE Multilin
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
D30 Line Distance 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
5.3 SYSTEM SETUP
5
PROD-
5-55