ABB RELION 620 Series Technical Manual page 353

1MAC504801-IB E
620 series ANSI
Technical Manual
Characteristic angle/
Max torque line
Min forward
angle
Non-operating area
Min trip voltage
Max reverse
angle
Min trip current
GUID-8BE1EAC6-FF7E-47F4-9333-A2E77917194F V1 EN
Figure 157: Configurable directional setting for "Measured VG" or "Calculated VN"
(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 an isolated network, Characteristic angle is set to -90°,
and in case of a compensated network, Characteristic angle is set 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 in maximum sensitivity. Characteristic
angle can be set anywhere between -179° to +180°. The figures show examples of the
operating area with RCA set to +60° and -90°, respectively.
RCA = 0 deg
-VG ( polarizing quantity)
IG ( operating quantity)
Max forward
angle
Zero torque line
Non-operating area
Min reverse
angle
Section 4
Protection functions
347