Scheme Logic - Toshiba GRL100-701B Instruction Manual

2.15.2 Scheme Logic

2.15.2.1 One-breaker Autoreclose
Figure 2.15.2.1 shows the simplified scheme logic for the single-shot autoreclose. Autoreclose
for a further fault incident is available when the circuit breaker is closed and ready for
autoreclose (CB-RDY=1), the reclosing mode selection switch [ARC-M] is set to "SPAR",
"TPAR", "SPAR & TPAR", "MPAR2" or "MPAR3" and the on-delay timer TRDY1 is picked
up. TRDY1 is used to determine the reclaim time.
If the autoreclose is ready, the internal tripping signal TRIP-A, B, C or external tripping signal
EXT_TRIP-A, B, C for each phase of the breaker activates the autoreclose. Whether or not the
external trip signals are used to activate the reclosing is selected by the scheme switch
[ARC-EXT].
Once this autoreclose is activated, it is kept by the flip-flop circuit until one reclosing cycle is
completed.
Autoreclose is not activated in the following conditions and all the phases are tripped
(M-TRIPA=1).
• When tripping is performed by the high-impedance earth fault protection (DIFGT=1) and
the autoreclose selection switch [ARC-DIFG] is set to "OFF".
• When tripping is performed by the backup protection (BU-TRIP=1) and the autoreclose
selection switch [ARC-BU] is set to "OFF".
• When tripping is performed by the out-of-step protection (OSTT=1), breaker failure
protection (RETRIP=1) or stub fault protection (STUB=1).
• When an autoreclose prohibiting binary input signal is applied at either the local or
remote terminal (ARC_BLOCK=1).
• When tripping is performed by the DEF command protection and the autoreclose
selection switch [ARC-DEFC] is set to "OFF".
If autoreclosing is not ready, a three-phase tripping command M-TRIPA is output for all tripping
modes. At this time, autoreclose is not activated.
Autoreclose for single-phase fault
If the switch [ARC-M] is set to "SPAR", "SPAR & TPAR" or "MPAR2", single-phase tripping
is performed. If it is set to "MPAR3", single-phase tripping is performed only when the adjacent
parallel line is healthy.
The dead time counter TSPR or TMPR for single-phase reclosing is started by any of the tripping
signals TRIP-A to C. After the dead time has elapsed, reclosing command ARC is output. The
voltage check condition can be configured by the PLC function, if the voltage check and others
are required for the reclosing condition.
If [ARC-M] is set to "TPAR", three-phase tripping is performed and the dead time counter
TTPR1 for three-phase reclosing is started. After the dead time has elapsed, reclosing command
ARC is output based on the operating conditions of the voltage and synchronism check elements
output signal SYN-OP. (The SYN-OP is assigned by the PLC as a default setting.)
If [ARC-M] is set to "Disable", three-phase tripping is performed and autoreclose is not started.
 115 
6 F 2 S 0 8 5 0