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
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
,
fA
fB
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
Summary of Contents for RED650
Page 1: ...RELION 650 SERIES Line differential protection RED650 Version 2 2 Application manual ...
Page 2: ......
Page 22: ...16 ...
Page 32: ...26 ...
Page 82: ...76 ...
Page 112: ...106 ...
Page 152: ...146 ...
Page 208: ...202 ...
Page 214: ...208 ...
Page 282: ...276 ...
Page 356: ...350 ...
Page 404: ...398 ...
Page 408: ...402 ...
Page 442: ...436 ...
Page 452: ...446 ...
Page 453: ...447 ...