ABB Relion Technical Manual page 222

Section 8
Current protection
216
polMethod. The polarizing quantity will be selected by the function in one of the following
three ways:
1. When polMethod = Voltage, VPol will be used as polarizing quantity.
2. When polMethod = Current, IPol will be used as polarizing quantity.
3. WhenpolMethod = Dual, VPol + IPol · ZNPol will be used as polarizing quantity.
The operating and polarizing quantity are then used inside the directional element, as
shown in figure 94, in order to determine the direction of the ground fault.
Characteristic
for PUREV
-RCA +85 deg
RCA -85 deg
Characteristic for forward
release of measuring steps
ANSI11000243 V1 EN
Figure 94: Operating characteristic for ground-fault directional element using the
zero sequence components
Operating area
PUREV
0.6 * INDirPU
Characteristic for reverse
release of measuring steps
40% of
INDirPU
RCA
65°
I = 3I
op
Operating area
Characteristic
for PUFW
1MRK 502 048-UUS A
-RCA -85 deg
VPol = -3V
INDirPU
PUFW
0
ANSI11000243-1-en.ai
Technical manual
RCA +85 deg
0