ABB Relion REC670, Applications Manual

Page: 303 / 658

100
3
2
2 3
 
VBase
V
PU V
EQUATION1757-ANSI V4 EN-US
(Equation 108)
where:
V2PU
is the maximal negative sequence voltage during normal operation conditions, plus a margin of
10...20%
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 109 .
100
2
2 3
 
IBase
I
PU I
EQUATION1758-ANSI V4 EN-US
(Equation 109)
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
13.2.3.4 Zero sequence based
M13683-43 v8
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 110 .
100
3
0 3
0 3
 
VBase
V
PU V
EQUATION1759-ANSI V4 EN-US
(Equation 110)
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
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
111 .
1MRK 511 401-UUS A
Section 13
Secondary system supervision
Bay control REC670 2.2 ANSI 297
Application manual