ABB 615 series Technical Manual page 398

Section 4
Protection functions
392
The combined overconductance and oversusceptance criterion is applicable in high-
resistance grounded, ungrounded and compensated networks or in the systems where the
system grounding may temporarily change during normal operation from compensated to
ungrounded system.
Im(Yo)
TRIP
Susceptance forward
Conductance forward
GUID-60D007C4-2B08-41FC-A30B-580B3DF37361 V1 EN
Figure 186: Combined forward directional overconductance and forward directional
oversusceptance characteristic. Left figure: the Conductance tilt Ang and
Susceptance tilt Ang settings equal zero degrees. Right figure: the
setting Conductance tilt Ang > 0 degrees and the setting Susceptance tilt
Ang < 0 degrees.
TRIP
TRIP
Susceptance forward
Conductance forward
Re(Yo)
TRIP
1MAC059074-MB A
Im(Yo)
Conductance tilt Ang >0
TRIP
Susceptance tilt Ang <0
Re(Yo)
TRIP
615 series ANSI
Technical Manual