Zero Sequence Based - ABB REB670 Applications Manual

Section 11
Secondary system supervision
11.1.3.4
276
I 2
 
3 I 2 PU 100
IBase
EQUATION1758-ANSI V4 EN
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

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 90.
3 V 0
 
3 V 0 PU 100
VBase 3
EQUATION1759-ANSI V4 EN
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
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 91.
3 0 I
3 0 I PU 100
= ×
IBase
EQUATION2293-ANSI V2 EN
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
1MRK 505 337-UUS -
(Equation 89)
GlobalBaseSel
(Equation 90)
GlobalBaseSel
(Equation 91)
GlobalBaseSel
Application manual