ABB REG670 - Page 373

directional supervision element and the integrated directional
comparison function.
The protection has integrated directional feature. As the operating quantity current lop
is always used. The polarizing method is determined by the parameter setting
polMethod. The polarizing quantity will be selected by the function in one of the
following three ways:
1. When polMethod = Voltage, UPol will be used as polarizing quantity.
2. When polMethod = Current, IPol will be used as polarizing quantity.
3. WhenpolMethod = Dual, UPol + IPol · ZNPol will be used as polarizing quantity.
The operating and polarizing quantity are then used inside the directional element, as
shown in figure
165, in order to determine the direction of the earth fault.
STRV
0.6 * IN>DIR
STFW
-RCA -85 deg
40% of
IN>DIR
IN>DIR
RCA
65°
U = -3U
pol 0
I = 3I
op 0
RCA +85 deg
RCA -85 deg
Characteristic
for STRV
Operating area
Operating area
Characteristic
for STFW
Characteristic for reverse
release of measuring steps
Characteristic for forward
release of measuring steps
-RCA +85 deg
IEC11000243-1-en.ai
IEC11000243 V1 EN
Figure 165: Operating characteristic for earth-fault directional element using the
zero sequence components
Two relevant setting parameters for directional supervision element are:
1MRK502052-UEN B Section 8
Current protection
367
Technical manual