ABB Relion 670 series - Zero Sequence Based

The setting of the current limit 3I2PU is in percentage of parameter IBase. The setting of
3I2PU must be higher than the normal unbalance current that might exist in the system and
can be calculated according to equation 528.
100
2
23 
IBase
I
PUI
EQUATION1758-ANSI V4 EN (Equation 528)
where:
I2 is the maximal negative sequence current during normal operating conditions, plus a margin of
10...20%
IBase is the base current for the function according to the setting GlobalBaseSel
14.2.3.4 Zero sequence based
The IED setting value 3V0PU is given in percentage of the base voltage VBase. The setting
of 3V0PU should not be set lower than the value that is calculated according to
equation 529.
100
3
03
03 
VBase
V
PUV
EQUATION1759-ANSI V4 EN (Equation 529)
where:
3V0 is the maximal zero sequence voltage during normal operation conditions, plus a margin of 10...20%
VBase is the base voltage for the function according to the setting GlobalBaseSel
The setting of the current limit 3I0PU is done in percentage of IBase. The setting of pickup
must be higher than the normal unbalance current that might exist in the system. The
setting can be calculated according to equation
530.
3 0
3 0 100= ×
I
I PU
IBase
EQUATION2293-ANSI V2 EN
(Equation 530)
where:
3I0PU is the maximal zero sequence current during normal operating conditions, plus a margin of 10...20%
IBase is the base current for the function according to the setting GlobalBaseSel
1MRK 506 369-UUS - Section 14
Secondary system supervision
Line distance protection REL670 2.2 ANSI 627
Application manual