Zero Sequence Based - ABB RELION RET670 Applications Manual

1MRK 504 163-UUS A
14.2.3.4
Transformer protection RET670 2.2 ANSI
Application manual
V 2
 
3 V 2 PU 100
VBase 3
EQUATION1757-ANSI V4 EN-US
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 498.
I 2
 
3 I 2 PU 100
IBase
EQUATION1758-ANSI V4 EN-US
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 499.
3 V 0
 
3 V 0 PU 100
VBase 3
EQUATION1759-ANSI V4 EN-US
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 500.
Secondary system supervision
GlobalBaseSel
GlobalBaseSel
Section 14
(Equation 497)
(Equation 498)
M13683-43 v8
(Equation 499)
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