ABB REB650 - Delta U and Delta I; Zero Sequence Based

9.1.3.4 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
38.
100
3
03
03 
UBase
U
U
EQUATION1521 V4 EN-US (Equation 38)
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
39.
3 0
3 0 100
I
I
IBase
= × <
EQUATION2293 V3 EN-US (Equation 39)
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
9.1.3.5 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.
The setting of DU> should be set high (approximately 60% of UBase) and the
current threshold DI< low (approximately 10% of IBase) to avoid unwanted
operation due to normal switching conditions in the network. The delta current and
delta voltage function shall always be used together with either the negative or zero
sequence algorithm. If USet
prim
is the primary voltage for operation of dU/dt and
ISet
prim
the primary current for operation of dI/dt, the setting of DU> and DI< will
be given according to equation
40 and equation 41.
DU
USet
UBase
prim
> = 100
.
EQUATION1523 V3 EN-US
(Equation 40)
Section 9 1MRK 505 388-UEN B
Secondary system supervision
148 Busbar protection REB650 2.2 IEC
Application manual