ABB Relion 670 series - Page 368

IEC06000437_2_en.vsd
IED
B A
E
B
E
A
X’
d
X
T
X
S
Zone 1 Zone 2
jX
R
X’
d
X
T
X
S
B
A
d
Apparent generator
impedance
Pole slip
impedance
movement
IEC06000437 V2 EN
Figure 192: Movements in the impedance plain
where:
X'
d
= transient reactance of the generator
X
T
= short-circuit reactance of the step-up transformer
Z
S
= impedance of the power system A
The detection of rotor angle is enabled when:
Section 6 1MRK505222-UUS C
Impedance protection
362
Technical reference manual