ABB RET670 Applications Manual

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
Figure 163: Impedance trajectory within the distance protection zones 1 and 2
during and after the fault on line B – D
3.6.12.2 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:
• They must generally be blocked during normal operation and released during
power swings.
• Their operation must be time delayed but shorter (with sufficient margin) than the
set time delay of normal distance protection zone 2, which is generally blocked by
the power swing.
• Their resistive reach setting must secure, together with the set time delay for their
operation, that the slowest expected swings pass the impedance operate area
without initiating their operation.
Section 3 1MRK504116-UUS C
IED application
368
Application manual

ABB RET670 Specifications

General

Rated Frequency	50/60 Hz
Inputs	Analog and binary inputs
Application	Protection of power systems
Communication Protocols	IEC 61850, DNP3, Modbus
Operating Temperature Range	-25°C to +55°C
Mounting	Rack mounted
Number of Binary Inputs	Up to 48
Number of Binary Outputs	32
Protection Functions	Overcurrent Protection
Outputs	Binary outputs
Enclosure	IP 54
Type	Line Differential Protection
Number of Analog Inputs	24