ABB REG670 Applications Manual page 258

Section 8
Impedance protection
252
Reactive Reach
jX
R
RV
Z Z
S S
IEC06000584 V2 EN
Figure 131: Measured impedance at voltage inversion
Forward direction:
Where
X
LLoc
X1
Fw
X1 = max( 1.5 x (X -X
Rv C LLOC
X1
Fw
When the calculation of X1Fwgives a negative value the zone 1 must
be permanently blocked.
For protection on non compensated lines facing series capacitor on next line. The
setting is thus:
• X1Fw is set to (XLine-XC · K) · p/100.
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
X - X
line
X
LLOC
R
FW
X
C
equals line reactance up to the series capacitor(in the picture
approximate 33% of XLine)
is set to (XLine-X ) · p/100.
C
C); is defined according to figure
1MRK 502 071-UEN -
C
R
en06000584-2.vsd
130
Application manual