ABB Relion 670 series - Stub Protection STBPTOC (50 STB)

9.8 Stub protection STBPTOC (50STB)
9.8.1 Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Stub protection STBPTOC
3I>STUB
SYMBOL-T V1 EN
50STB
9.8.2 Application
In a breaker-and-a-half switchyard the line protection and the busbar protection normally
have overlap when a connected object is in service. When an object is taken out of service
it is normally required to keep the diagonal of the breaker-and-a-half switchyard in
operation. This is done by opening the disconnector to the protected object. This will,
however, disable the normal object protection (for example the distance protection) of the
energized part between the circuit breakers and the open disconnector.
Stub protection STBPTOC (50STB) is a simple phase overcurrent protection, fed from the
two current transformer groups feeding the object taken out of service. The stub protection
is only activated when the disconnector of the object is open. STBPTOC (50STB) enables
fast fault clearance of faults at the section between the CTs and the open disconnector.
Section 9 1MRK 506 369-UUS -
Current protection
544 Line distance protection REL670 2.2 ANSI
Application manual