ABB RED615 Technical Manual page 333

1YHT530004D05 D
615 series
Technical Manual
Forward directional oversusceptance characteristic
The forward directional oversusceptance criterion is enabled with the Operation
mode setting set to "Bo" and Directional mode to "Forward". The characteristic is
defined by one oversusceptance boundary line with the Susceptance forward
setting. For the sake of application flexibility, the boundary line can be tilted by the
angle defined with the Susceptance tilt Ang setting. By default, the tilt angle is zero
degrees, that is, the boundary line is a horizontal line in the admittance plane. A
positive tilt value rotates the boundary line counterclockwise from the horizontal axis
Operation is achieved when the measured admittance moves over the boundary line.
The forward directional oversusceptance criterion is applicable in
unearthed networks. It must not be applied in compensated networks.
Im(Yo)
OPERATE OPERATE
Susceptance forward
Re(Yo)
Re(Yo)
GUID-43B0F2F9-38CE-4F94-8381-0F20A0668AB1 V1 EN
Figure 165: Forward directional oversusceptance characteristic. Left figure:
classical forward directional oversusceptance criterion. Middle
figure: characteristic is tilted with negative tilt angle. Right figure:
characteristic is tilted with positive tilt angle.
Combined overadmittance and overconductance characteristic
The combined overadmittance and overconductance criterion is enabled with the
Operation mode setting set to "Yo, Go" and Directional mode to "Non-directional".
The characteristic is a combination of a circle with the radius defined with the
Circle radius setting and two overconductance boundary lines with the settings
Conductance forward and Conductance reverse. For the sake of application
flexibility, the midpoint of the circle can be moved from the origin with the Circle
conductance and Circle susceptance settings. Also the boundary lines can be tilted
by the angle defined with the Conductance tilt Ang setting. By default, the Circle
conductance and Circle susceptance are 0.0 mS and Conductance tilt Ang equals
zero degrees, that is, the characteristic is a combination of an origin-centered circle
with two vertical overconductance boundary lines. A positive tilt value for the
Conductance tilt Ang setting rotates boundary lines counterclockwise from the
vertical axis.
Im(Yo)
OPERATE OPERATE
Susceptance tilt Ang <0
Susceptance forward
Re(Yo)
Re(Yo)
Section 4
Protection functions
Im(Yo)
OPERATE OPERATE
Susceptance tilt Ang >0
Susceptance forward
Re(Yo)
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