ABB RED650 Applications Manual

GlobalBaseSel: This is used to select GBASVAL function for reference of base
values.
The basic requirement is to assure selectivity, that is EFPIOC shall not be allowed
to operate for faults at other objects than the protected object (line).
For a normal line in a meshed system single phase-to-earth faults and phase-to-
phase-to-earth faults shall be calculated as shown in Figure
78 and Figure 79. The
residual currents (3I
0
) to the protection are calculated. For a fault at the remote line
end this fault current is I
fB
. In this calculation the operational state with high source
impedance Z
A
and low source impedance Z
B
should be used. For the fault at the
home busbar this fault current is I
fA
. In this calculation the operational state with
low source impedance Z
A
and high source impedance Z
B
should be used.
~
~
Z
A
Z
B
Z
L
A B
IED
I
fB
Fault
IEC09000022-1-en.vsd
IEC09000022 V1 EN-US
Figure 78: Through fault current from A to B: I
fB
IEC09000023-1-en.vsd
~ ~
Z
A
Z
B
Z
L
A B
IED
I
fA
Fault
IEC09000023 V1 EN-US
Figure 79: Through fault current from B to A: I
fA
The function shall not operate for any of the calculated currents to the protection.
The minimum theoretical current setting (Imin) will be:


Im ,
f
AfB
in MAX I I
EQUATION284 V2 EN-US
(Equation 107)
Section 8 1MRK 505 393-UEN B
Current protection
164 Line differential protection RED650 2.2 IEC
Application manual

ABB RED650 Specifications

General

Brand	ABB
Model	RED650
Category	Protection Device
Language	English