ABB Relion 670 Series Applications Manual page 286

Section 12
Control
12.2.1 Identification
Function Description
Autorecloser for 1 phase, 2 phase and/or 3
phase
12.2.2 Application
In certain countries it is standard practice to provide delayed restoration after busbar protection operation
for internal fault, reason being that many busbar faults are of the transient natures that is, animals, birds,
storm, flying objects, etc. In such applications, typically one pre-selected feeder is automatically closed
with certain time delay in order to try to re-energize the faulty bus. Typically, the longest overhead line is
selected in order to limit the fault current in case of permanent busbar fault. If the first feeder is
successfully closed, all other feeder which have been connected to the same busbar, are automatically
put back into service.
Sensitive differential protection level available in REB670 can be used during such operation, if increased
sensitivity from busbar protection is required. Such busbar restoration logic can be implemented by using
optionally available auto reclosers and built-in logical gates. Two auto reclosers are available.
Automatic reclosing is a well-established method for the restoration of service in a power system after a
transient line fault. The majority of line faults are flashovers, which are transient by nature. When the
power line is switched off by the operation of line protection and line breakers, the arc de-ionizes and
recovers its ability to withstand voltage at a somewhat variable rate. Thus, a certain dead time with a de-
energized line is necessary. Line service can then be resumed by automatic reclosing of the line
breakers. The dead time selected should be long enough to ensure a high probability of arc de-ionization
and successful reclosing.
For individual line breakers, auto reclosing equipment, the required circuit breaker dead time is used to
determine the "dead time" setting value. When simultaneous tripping and reclosing at the two line ends
occurs, line dead time is approximately equal to the auto recloser "dead time". If the auto reclosing dead
time and line "dead time" differ then, the line will be energized until the breakers at both ends have
opened.
280
IEC 61850
identification
SMBRREC
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1MRK 505 370-UUS Rev. K
IEC 60617 ANSI/IEEE C37.2
identification device number
79
5(0 -->1)
IEC15000204 V1 EN-US
Busbar protection REB670
M14890-1 v7
M12391-3 v8
Application manual