Protecting Single-Circuit Lines - ABB ETL600 Instruction Manual

ETL600
MP1: 1st main protection
MP2: 2nd main protection
BFP: breaker failure protection
+ overvoltage protection
+ compensator protection
Fig. 3-38
The settings for the permissive main protection commands should as
given in section 3.6.5.1 and those for the direct tripping commands as
given in section 3.6.5.2.
3.6.5.6.

Protecting Single-Circuit Lines

One or two signals - one for a permissive scheme and possibly a direct
transfer tripping signal - are usually sufficient when protecting lines in
the low to medium voltage range.
This task can be easily accomplished with the NSD600 using one relay
interface. Since the interface has four input and six output circuits,
further functions can be activated, e.g. start input, unblocking or
redundant command output. One of the commands is programmed to
be "permissive" with short transmission time and the other to "direct".
The following recommended settings thus result:
Command output type:
Application of command 1
Application of command 2
Command prolongation for command 1:
Command prolongation for command 2:
Structure and Function
1KHW001489-EN
MP1 Line 1
A
MP2 Line 2 B
BFP Line 1
C
BFP Line 2
D NSD600
MP1 Line 2
A
MP2 Line 1
B
C
D
Redundant protection of a dual-circuit line
ABB Switzerland Ltd
ETL600
ETL600
NSD600
CF: coupling filter
solid state
permissive
direct
10 ms
100 ms
November 2005
LINE 1
B PHASE
CF 1
CF 2
LINE 2
B PHASE
3-63