ABB 615 Series - Page 397

Re(Yo)
Im(Yo)
Im(Yo)
TRIPTRIP
Re(Yo)
Circleradius
Circleradius
Circleconductance
Circlesusceptance
Conductanceforward
Conductancereverse
TRIPTRIP
Conductanceforward
Conductancereverse
TRIPTRIP
TRIPTRIP
ConductancetiltAng
GUID-1CA6B05B-D011-47E0-B251-7F5F6C18C81F V1 EN
Figure 185: Combined overadmittance and overconductance characteristic. Left
figure: classical origin-centered admittance circle combined with two
overconductance boundary lines. Right figure: admittance circle is set off
from the origin.
Combined overconductance and oversusceptance characteristic
The combined overconductance and oversusceptance criterion is enabled with the
Operation mode setting set to "Go, Bo".
By setting Directional mode to "Forward", the characteristic is a combination of two
boundary lines with the settings Conductance forward and Susceptance forward. See
Figure 186.
By setting Directional mode to "Non-directional", the characteristic is a combination of
four boundary lines with the settings Conductance forward, Conductance reverse,
Susceptance forward and Susceptance reverse. See
Figure 187.
For the sake of application flexibility, the boundary lines can be tilted by the angle defined
with the Conductance tilt Ang and Susceptance tilt Ang settings. By default, the tilt angles
are zero degrees, that is, the boundary lines are straight lines in the admittance plane. A
positive Conductance tilt Ang value rotates the overconductance boundary line
counterclockwise from the vertical axis. A positive Susceptance tilt Ang value rotates the
oversusceptance boundary line counterclockwise from the horizontal axis.
In case of the non-directional conductance and susceptance criteria, the Conductance
reverse setting must be set to a smaller value than Conductance forward and the
Susceptance reverse setting must be set to a smaller value than Susceptance forward.
Operation is achieved when the measured admittance moves outside the characteristic.
1MAC059074-MB A Section 4
Protection functions
615 series ANSI 391
Technical Manual