Zero Sequence Based - ABB Relion REC670 Applications Manual

Section 12
Secondary system supervision

3 U 2
UBase
EQUATION1519 V5 EN-US
where:
U2
UBase
The setting of the current limit
must be higher than the normal unbalance current that might exist in the system and can be
calculated according to equation 112.

3 I 2
EQUATION1520 V5 EN-US
where:
I2
IBase
12.2.3.4

Zero sequence based

The IED setting value
3U0> should not be set lower than the value that is calculated according to equation 113.

3 U 0
EQUATION1521 V4 EN-US
where:
3U0
UBase
The setting of the current limit
be higher than the normal unbalance current that might exist in the system. The setting can be
calculated according to equation 114.
<
3 0 I
=
EQUATION2293 V3 EN-US
where:
3I0<
IBase
220
U 2

100
3
is the maximal negative sequence voltage during normal operation conditions, plus a margin of
10...20%
is the base voltage for the function according to the setting
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
3U0> is given in percentage of the base voltage UBase . The setting of
3 U 0

100
UBase 3
is the maximal zero sequence voltage during normal operation conditions, plus a margin of 10...20%
is the base voltage for the function according to the setting
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
3I2< is in percentage of parameter IBase . The setting of 3I2<
3I0< is done in percentage of IBase . The setting of 3I0< must
1MRK 511 358-UEN A
GlobalBaseSel
GlobalBaseSel
GlobalBaseSel
GlobalBaseSel
Application manual
(Equation 111)
(Equation 112)
M13683-43 v8
(Equation 113)
(Equation 114)