Micom P634 - Page 129

3.12.5.1 Possible Combinations to Form a Virtual Transformer End
The following combinations are possible:
●
Forming the sum of the phase currents or of the residual currents from two
ends of the transformer.
The following options exist:
o
End(a)+end(b)
o
End(a)+end(c)
o
End(b)+end(c)
o
End(a)+end(d)
o
End(b)+end(d)
o
End(c)+end(d)
●
Forming the sum of the phase currents or of the residual currents from
three ends of the transformer.
The following options exist:
o
End(a)+end(b)+end(c)
o
End(a)+end(b)+end(d)
o
End(a)+end(c)+end(d)
o
End(b)+end(c)+end(d)
●
Subtracting the phase currents or the residual currents from two ends of
the transformer. By subtraction (unstable) transverse differential protection
including time-overcurrent protection may be obtained.
The following options exist:
o
End(a)-end(b)
o
End(a)-end(c)
o
End(a)-end(d)
o
End(b)-end(c)
o
End(b)-end(d)
o
End(c)-end(d)
3 Operation P634
P634/EN M/R-42-A // P634‑311‑653 3-73