1
a g Re
ABM
AB
V
AngDir n AngNeg s
I
- < <
EQUATION2007 V2 EN (Equation 23)
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
AM
is positive sequence memorized phase voltage in phase A
I
A
is phase current in phase A
V1
ABM
is memorized voltage difference between phase A and B (B lagging A)
I
AB
is current difference between phase A and B (B lagging A)
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.
R
X
AngDir
AngNegRes
en05000722_ansi.vsd
ANSI05000722 V1 EN
Figure 93: Setting angles for discrimination of forward and reverse fault
Section 6 1MRK505222-UUS C
Impedance protection
206
Technical reference manual
To Next Page
Loading...
