ABB Relion 670 Series Technical Reference Manual page 212

Section 6
Impedance protection
206
V 1
ABM
- < <
AngDir a g n
I
AB
EQUATION2007 V2 EN
where:
AngDir
is the setting for the lower boundary of the forward directional characteristic, by default set to
15 (= -15 degrees) and
AngNegRes is the setting for the upper boundary of the forward directional characteristic, by default set
to 115 degrees, see figure 93.
V1 is positive sequence memorized phase voltage in phase A
AM
I is phase current in phase A
A
V1 is memorized voltage difference between phase A and B (B lagging A)
ABM
I is current difference between phase A and B (B lagging A)
AB
The setting of AngDir and AngNegRes is by default set to 15 (= -15) and 115 degrees
respectively, see figure 93, and it should not be changed unless system studies have
shown the necessity.
ZDSRDIR (21D) generates a binary coded signal on the output STDIR depending on
the evaluation where FWD_A=1 adds 1, REV_A=1 adds 2, FWD_B=1 adds 4.
X
ANSI05000722 V1 EN
Figure 93: Setting angles for discrimination of forward and reverse fault
AngNeg Re s
AngNegRes
AngDir
R
en05000722_ansi.vsd
1MRK505222-UUS C
(Equation 23)
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