ABB Relion 670 Series Applications Manual page 289

1MRK 505 370-UUS Rev. K
When Single and/or three phase auto reclosing is considered, there are a number of cases where the
tripping shall be three phase anyway. For example:
• Evolving fault where the fault during the dead-time spreads to another phase. The other two phases
must then be tripped and a three phase dead-time and auto reclose initiated
• Permanent fault
• Fault during three-phase dead time
• Auto recloser out of service or circuit breaker not ready for an auto reclosing cycle
"Prepare three-pole tripping" is then used to switch the tripping to three-pole. This signal is generated by
the auto-recloser and connected to the trip function block and also connected outside the IED through IO
when a common auto-recloser is provided for two sub-systems. An alternative signal "Prepare 1 Pole
tripping" is also provided and can be used as an alternative when the autorecloser is shared with another
subsystem. This provides a fail safe connection so that even a failure in the IED with the auto-recloser
will mean that the other sub-system will start a three-pole trip.
A permanent fault will cause the line protection to trip again when it recloses in an attempt to energize
the line.
The auto reclosing function allows a number of parameters to be adjusted.
Examples:
• number of auto reclosing shots
• auto reclosing program
• auto reclosing dead times for each shot
12.2.2.1 Auto reclosing operation Off and On
Operation of the automatic recloser can be set to Off and On by a setting parameter or by external
control. The setting parameter Operation = Disabled, or Enabled sets the function to Off or On. With the
settings Operation = Enabled and ExternalCtrl = Enabled , the control is made by input signal pulses to
the inputs On and Off, for example, from a control system or by a control switch.
When the auto recloser is set On, the SETON output is set, and the auto recloser becomes operative if
other conditions such as circuit breaker is closed and circuit breaker is ready are also fulfilled, the
READY output is activated (high). Then the auto recloser is ready to accept a start.
12.2.2.2 Initiate auto reclosing and conditions for start of a reclosing cycle
The usual way to start an auto reclosing cycle, or sequence, is to start it at selective tripping by line
protection by applying a signal to the RI input. Starting signals can be either, general trip signals or, only
the conditions for differential, distance protection zone 1 and distance protection aided trip. In some
cases also directional ground fault protection aided trip can be connected to start an auto reclose
attempt. If general trip is used to start the auto recloser it is important to block it from other functions that
should not start an auto reclosing sequence.
In cases where one wants to differentiate three-phase auto reclosing dead time, for different power
system configuration or at tripping by different protection stages, one can also use the RI_HS input
(initiate high-speed reclosing). When initiating RI_HS , the auto reclosing dead time for three-phase shot
1, t1 3PhHS is used and the closing is done without checking the synchrocheck condition.
A number of conditions need to be fulfilled for the start to be accepted and a new auto reclosing cycle to
be started. They are linked to dedicated inputs. The inputs are:
Busbar protection REB670
Application manual
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Section 12
Control
M12391-91 v6
M12391-94 v5
283