ABB Relion 670 Series Applications Manual page 182

Section 8
Current protection
Document
revision
D
E
F
G
H
8.9.2 Identification
Function description
Breaker failure protection, 3-phase
activation and output
8.9.3 Application
In the design of the fault clearance system the N-1 criterion is often used. This means that a
fault needs to be cleared even if any component in the fault clearance system is faulty. One
necessary component in the fault clearance system is the circuit breaker.
It is from practical and economical reason not feasible to duplicate the circuit breaker for the
protected object. Instead a breaker failure protection is used.
Breaker failure protection CCRBRF will issue a backup trip command to adjacent circuit
breakers in case of failure to trip of the "normal" circuit breaker for the protected object. The
detection of failure to break the current through the breaker is made either by means of
current measurement or as detection of closed status using auxiliary contact.
CCRBRF can also give a retrip command. This means that a second trip signal is sent to the
protected object circuit breaker. The retrip function can be used to increase the probability of
operation of the breaker, or it can be used to avoid backup trip of many breakers in case of
mistakes during relay maintenance and testing.
8.9.4 Setting guidelines
The parameters for Breaker failure protection CCRBRF are set via the local HMI or PCM600.
The following settings can be done for the breaker failure protection.
GlobalBaseSel : Selects the global base value group used by the function to define IBase , UBase
SBase . Note that this function will only use IBase value.
and
Operation : Off / On to enable/disable the complete function.
FunctionMode : It defines the way the detection of failure of the breaker is performed. In the
Current mode, the current measurement is used for the detection. In the CB Pos mode, the CB
auxiliary contact status is used as an indicator of the failure of the breaker. The mode
CB Pos means that both ways of detections can be activated. The CB Pos mode is used in
or
applications where the fault current through the circuit breaker is small. This can be the case
176
Product History
revision
StartMode is added to choose how retrip and backup trip timers are run.
2.2.3 Setting
The choices are; to run the timers by external start signal which is latched, to follow
the external start signal only or to follow the external start signal and the selected
FunctionMode .
2.2.3 -
2.2.3 -
2.2.4 -
2.2.4 -
IEC 61850
identification
CCRBRF
© Copyright 2017 Hitachi Power Grids. All rights reserved
IEC 60617 ANSI/IEEE C37.2
identification device number
50BF
3I>BF
SYMBOL-U V1 EN-US
1MRK 511 401-UEN Rev. K
M14878-1 v5
M13916-3 v8
M11546-4 v10
Current
Bay control REC670
Application manual