ABB Relion Technical Manual page 185

1MRK 502 048-UUS A
Technical manual
4
3
normal
load
Z(R, X) under fault lies
2
on the impedance line
or near (for 3-ph faults)
1
0
fault 500 ms
fault
-1
occurrs
Under 3-phase fault
condition rotor angle
-2
of app. ±180 degrees
is measured ...
-3
-4
0 200 400
IEC10000110 V1 EN
Figure 77: Rotor (power) angle and magnitude of the complex impedance Z(R, X)
against the time
In order to be able to fully understand the principles of OOSPPAM (78), a stable case, that
is, a case where the disturbance does not make a generator to go out-of-step, must be
shown.
|Z| in Ohms
rotor (power)
angle in rad
angle
|Z|
Z(R,X) crossed
the impedance line, Z-line,
connecting points SE - RE
600 800 1000
Time in milliseconds →
Section 7
Impedance protection
1200 1400
IEC10000110-1-en.vsd
179