ABB Relion 670 Series Applications Manual page 259

1MRK 505 370-UUS Rev. K

3 V 2 PU
EQUATION1757-ANSI V4 EN-US
where:
V2PU
VBase is the base voltage for the function according to the setting GlobalBaseSel
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 88.

3 I 2 PU
EQUATION1758-ANSI V4 EN-US
where:
I2
IBase
11.1.3.4 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 89.
3 V 0 PU
EQUATION1759-ANSI V4 EN-US
where:
3V0
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 90.
3 0 I PU
EQUATION2293-ANSI V2 EN-US
where:
3I0PU
IBase
Busbar protection REB670
Application manual
V 2

100
VBase 3
is the maximal negative sequence voltage during normal operation conditions, plus a margin of 10...20%
I 2

100
IBase
is the maximal negative sequence current during normal operating conditions, plus a margin of 10...20%
is the base current for the function according to the setting GlobalBaseSel
3 V 0
 
100
VBase 3
is the maximal zero sequence voltage during normal operation conditions, plus a margin of 10...20%
3 0 I
100
= ×
IBase
is the maximal zero sequence current during normal operating conditions, plus a margin of 10...20%
is the base current for the function according to the setting GlobalBaseSel
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Section 11
Secondary system supervision
(Equation 87)
(Equation 88)
M13683-43 v8
(Equation 89)
(Equation 90)
253