GE UR Series Instruction Manual page 111

5 SETTINGS
USER SELECTION OF AC PARAMETERS FOR COMPARATOR ELEMENTS:
CT/VT modules automatically calculate all current and voltage parameters that can be calculated from the inputs available.
Users will have to select the specific input parameters that are to be measured by every element, as selected in the ele-
ment settings. The internal design of the element specifies which type of parameter to use and provides a setting for selec-
tion of the Source. In some 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 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 input sections of Actual Values. Only the phasor quantities associated with the actual AC physical input channels will
be displayed here. All parameters contained within a configured Source are displayed in the Sources section of Actual Val-
ues.
DISTURBANCE DETECTORS (Internal):
The 50DD element is a sensitive current disturbance detector that is used to detect any disturbance on the protected sys-
tem. 50DD is intended for use in conjunction with measuring elements, blocking of current based elements (to prevent mal-
operation as a result of the wrong settings), and starting oscillography data capture. A disturbance detector is provided for
every Source.
The 50DD function responds to the changes in magnitude of the sequence currents.
The disturbance detector scheme logic is as follows:
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
EXAMPLE USE OF SOURCES:
An example of the use of Sources, with a relay with three CT/VT modules, is shown in the diagram below. A relay could
have the following hardware configuration:
INCREASING SLOT POSITION LETTER -->
CT/VT MODULE 1 CT/VT MODULE 2
CTs CTs
CTs VTs
GE Power Management
LOGIC
Where ' is 2 cycles old
LOGIC
Where ' is 2 cycles old
LOGIC
Where ' is 2 cycles old
Figure 5–3: DISTURBANCE DETECTOR LOGIC DIAGRAM
CT/VT MODULE 3
VTs
---
L90 Line Differential Relay
I _1 - I _1' > 0.04pu FLEXLOGIC OPERAND
I _2 - I _2' > 0.04pu
OR SRC 1 50DD OP
I _0 - I _0' > 0.04pu
I
I _1 - I _1' > 0.04pu FLEXLOGIC OPERAND
SRC 2 50DD OP
I _2 - I _2' > 0.04pu OR
I _0 - I _0' > 0.04pu
I
I _1 - I _1' > 0.04pu
FLEXLOGIC OPERAND
I _2 - I _2' > 0.04pu OR SRC 6 50DD OP
I _0 - I _0' > 0.04pu
I
5.3 SYSTEM SETUP
827092A2.CDR
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