ABB Relion 670 Series Applications Manual page 187

1MRK 511 401-UUS F
8.9.1 Identification
Function description
Breaker failure protection, 3-phase
activation and output
8.9.2 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 (50BF)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 (50BF) 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.
8.9.3 Setting guidelines
The parameters for Breaker failure protection CCRBRF (50BF) 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 , VBase and
SBase . Note that this function will only use IBase value.
Operation : Disabled / Enabled 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
applications where the fault current through the circuit breaker is small. This can be the case for
some generator protection application (for example, reverse power protection) or in the case of
line ends with weak end infeed.
StartMode : By this setting it is possible to select how t1 and t2 timers are run and consequently
how output commands are given from the function:
Option 1 - LatchedStart : "By external start signals which is internally latched".
•
Bay control REC670
Application manual
IEC 61850
identification
CCRBRF
© Copyright 2017 ABB. All rights reserved
IEC 60617 ANSI/IEEE C37.2
identification device number
50BF
3I>BF
SYMBOL-U V1 EN-US
Section 8
Current protection
M14878-1 v5
M13916-3 v8
M11546-4 v10
Current or
181