ABB RELION 650 Series Applications Manual page 104

Section 6
Differential protection
Setting example for two transformers in the zone, Master- Slave differential operation
IEC13000295 V1 EN-US
Figure 51:
Settings
PDIF
NoOfUsedCTs
TraAOnInpCh
TraBOnInpCh
The protection at B and C are operating as Slaves (differential function switched off) and the
currents are sent to the protection at A and received on channel 2 and 3. To inform the
differential algorithm that the currents are from the low voltage sides of the transformers,
TraAOnInpCh has to set to 2 and TraBOnInpCh to 3 (channel1 is reserved for local
measurement) so that the proper turn ratio and vector group correction can be done.
Setting example for three-winding transformer in the zone
A
RED
670
IEC13000296 V1 EN-US
Figure 52: Three-winding transformer in the zone (example showing 670 device)
Settings
PDIF
NoOfUsedCTs
raAOnInpCh
T
TraBOnInpCh
The currents from the secondary and tertiary windings of the power transformer are
connected to one RED670. The currents for each CT group are sent to the RED670 at A station
98
A
Master- Slave differential operation (example showing 670 device)
Station A
L3TC PDIF
3
2
3
Station A
L3TC PDIF
3
2
3
T
T
Station B Station C
T
T
Station B
L3TC PDIF
3
1
2
1MRK 505 363-UEN A
B
C
IEC13000295-1-en.vsd
B
RED
670
IEC13000296-1-en.vsd
Application manual