ABB REL670 2.2 IEC, Applications Manual

Page: 423 / 908

E
A
A
B
C
D
F
Z
SA RA
E
C
E
D
xx06000238.vsd
Z
SC
Z
SD
IEC06000238 V1 EN-US
Figure 226: Fault on adjacent line and its clearance causes power swinging
between sources A and C
PSLPSCH function and the basic operating principle of ZMRPSB function operate
reliably for different faults on parallel power lines with detected power swings. It
is, however, preferred to keep the distance protection function blocked in cases of
single phase-to-earth faults on so far healthy lines with detected power swings. In
these cases, it is recommended to use an optionally available directional
overcurrent earth-fault protection with scheme communication logic.
R
jX
B
A
Measured
impedance at initital
fault position
Impedance locus at initial power
swing after the fault clearance
ZMRPSB operating characteristic
Zone 2
Zone 1
IEC99000181_2_en.vsd
IEC99000181 V2 EN-US
Figure 227: Impedance trajectory within the distance protection zones 1 and 2
during and after the fault on line B – D
1MRK 506 369-UEN B
Section 8
Impedance protection
Line distance protection REL670 2.2 IEC 417
Application manual