ABB RER620 - Page 273

1MAC309294-MB F Section 4
Protection functions
RER620 267
Technical Manual
Figure 132: Configurable directional setting for “Measured V
G
” or “Calculated V
N
”
(residual voltage) using
Pol signal Sel setting
The Characteristic angle setting is done based on method of grounding employed in the
network. For example in case of isolated network the Characteristic angle is set equal to
-90˚, in case of compensated network the Characteristic angle is set equal to 0˚ and 60˚
for solidly grounded systems. In general Characteristic angle is selected so that it matches
close to the expected fault angle value, which results into maximum sensitivity. The
Characteristic angle can be set anywhere between -179˚ to +180˚. Figure 133 and Figure
134 show examples of the operating area with RCA set to +60˚ and -90˚, respectively.
The directional characteristic for measured or calculated residual power is
same.
-VG ( polarizing quantity)
Max forward
angle
Min forward
angle
Min reverse
angle
Non-operating area
Forward
area
IG ( operating quantity)
Max reverse
angle
Backward
area
Non-operating area
Characteristic angle/
Max torque line
Min operate voltage
Min operate current
RCA = 0 deg
Zero torque line