ABB RER620 - Page 150

Section 4 1MAC309294-MB F
Protection functions
144 RER620
Technical Manual
Figure 60: Definition of the relay characteristic angle, RCA=+60 degrees in a solidly
grounded network
Example 3.
The “Phase angle” mode is selected, isolated network (φRCA = -90 deg)
=> Characteristic angle = -90 deg
N
o
n
-
o
p
e
r
a
t
i
n
g
a
r
e
a
Min reverse angle
Min operate
current
Max forward angle
Max reverse angle
Characteristic angle
= +60 deg
Min forward angle
maximum torque line
zero torque line
- (polarizing quantity)
(operating quantity)
0
V
0
I