Application; Signals; Settings - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.4.2.7
4.4.2.8
4.4.2.9
Table 674: DNSPDOC Group settings (Basic)
Parameter
Start value
Directional mode
Operate delay time
Characteristic angle
Max forward angle
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Application

The ability of a protection relay to provide direction information for faults is referred
to as its directional security. It is extremely important for the directional protection
function to identify the direction of the fault relative to the location of the protection
relay. The fault direction can be either downstream (forward fault) or upstream of the
protection relay (backward fault).
Different directional elements are used to determine the fault direction. One such
element is the negative-sequence voltage. As directional element, the negative-
sequence voltage can identify the direction of all unbalance faults. One of the
advantages of using negative-sequence elements is that the negative-sequence
component is insensitive to zero-sequence mutual coupling. The negative sequence is
also used where the source is not strong enough because with such a source the value
of the negative sequence near the protection relay has higher magnitude.

Signals

Table 672: DNSPDOC Input signals
Name
I3P
IRES
U3P
BLOCK
Table 673: DNSPDOC Output signals
Name
OPERATE
START

Settings

Values (Range) Unit
0.05...5.00 xIn
1=Non-directional
2=Forward
3=Reverse
40...300000 ms
-179...180 deg
0...90 deg
Type Default Description
SIGNAL - Three-phase currents
SIGNAL - Residual current
SIGNAL - Three-phase voltages
BOOLEAN 0=False Block signal for activating the blocking mode
Type Description
BOOLEAN Operate
BOOLEAN Start
Step Default
0.01 0.05
2=Forward
10 40
1 60
1 80
1MRS759142 C
Description
Start value
Directional mode
Operate delay time
Characteristic angle
Maximum phase angle in forward
direction
Technical Manual
REX640