ABB ret650 - Delta U and Delta I; Zero Sequence Based

100
2
23 
IBase
I
I
EQUATION1520 V5 EN-US (Equation 41)
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
10.2.3.4 Zero sequence based
M13683-43 v8
The IED setting value 3U0> is given in percentage of the base voltage UBase. The
setting of 3U0> should not be set lower than the value that is calculated according
to equation 42.
100
3
03
03 
UBase
U
U
EQUATION1521 V4 EN-US (Equation 42)
where:
3U0 is the maximal zero sequence voltage during normal operation conditions, plus a margin of
10...20%
UBase is the base voltage for the function according to the setting GlobalBaseSel
The setting of the current limit 3I0< is done in percentage of IBase. The setting of
3I0< must be higher than the normal unbalance current that might exist in the
system. The setting can be calculated according to equation 43.
3 0
3 0 100
I
I
IBase
= × <
EQUATION2293 V3 EN-US
(Equation 43)
where:
3I0< 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
10.2.3.5 Delta U and delta I
GUID-02336F26-98C0-419D-8759-45F5F12580DE v7
Set the operation mode selector OpDUDI to On if the delta function shall be in
operation.
1MRK 504 169-UEN A Section 10
Secondary system supervision
Transformer protection RET650 2.2 IEC 173
Application manual