Setting Guidelines - ABB RELION RET670 Applications Manual

Section 8
Impedance protection
8.15.3
8.15.3.1
460
jX
Zone 2
B
Zone 1
A
ZMRPSB operating characteristic
IEC99000181 V2 EN-US
Figure 231: Impedance trajectory within the distance protection zones 1 and 2
during and after the fault on line B – D

Setting guidelines

Scheme communication and tripping for faults occurring during power
swinging over the protected line
The IED includes generally up to five distance protection zones. It is possible to use
one or two of them intentionally for selective fault clearing during power swings only.
Following are the basic conditions for the operation of the so called (underreaching and
overreaching) power-swing zones:
Measured
impedance at initital
fault position
Impedance locus at initial power
swing after the fault clearance
Transformer protection RET670 2.2 ANSI
1MRK 504 163-UUS A
R
IEC99000181_2_en.vsd
SEMOD171741-1 v1
SEMOD131360-4 v2
Application manual