Once the collector substation is disconnected, the previously described basic principles of auto-
reclosing apply. This method applies to all meshed or ring networks where the same line is fed power
from multiple directions. This problem does not exist for typical consumer (radial) networks.
Arcing time and discrimination time
Generally, after the dead time has elapsed and the breaker is closed by the auto-recloser, this
happens: the reclaim time starts calculating and if the process is interrupted by a new reclosing
request, the function continues to the next state (the next available shot, or the Final Trip if no more
shots are available). However, the user can use the "Shot action time" setting to contol this behavior.
The two settings are mutually exclusive: when "Arcing" is selected for a shot, "Discrimination" cannot be
selected for the same shot.
The "Arcing" setting is used to control the auto-recloser when the START signal of a stage makes the
requests. If the request (e.g. I> START) activates during the reclaim time, an arcing time calculation
begins. If the fault persists, the function continues to the next state. If an arcing time calculation begins
but stops before the set time has passed, the reclaim calculation continues normally. When that time
has elapsed, the auto-recloser function returns either to the general reclaim time or to the Ready
mode; the shot is considered successful. The arcing time counter does not reset when the reclaim
calculation continues: every time it activates, it continues from where it left off. This means that the time
set to the "ARx Shot action time" parameter is a cumulative counter of time allowed before deciding
whether a shot is failed or successful.
The auto-recloser is sometimes used in time-coordinated, IDMT-protected networks that have old
mechanical relays with current-dependent release times. In these cases the operation of the protection
selectivity must be guaranteed by allowing all relay timing devices to completely reset during dead time
to maintain the correct time discrimination after reclosing to the fault. Some mechanical IDMT relays
can require up to ten seconds (10 s) to reset. When short dead times are required, the relays should
reset almost immediately for the current-dependent time grading to operate as expected, and set
the discrimination time (instead of the arcing time) to start simultaneously with the reclaim time. If new
reclosing requests are made during this discrimination time, the function halts and lets the protection
devices operate based on their own settings, and does not interfere with the protection functions' or the
breaker's operation. However, this means that the auto-recloser has to be manually reset and the
breaker manually closed before further reclosing requests can be made.
Auto-recloser I/O
The main outputs of the auto-recloser function are the control signals OBJECT OPEN and OBJECT
CLOSE. The function also reports the recloser status information which is used in the logics, LED
indications, and applied operations.
The inputs of the function are the following:
• binary recloser request signals
• blockings
• controlling signals
• the controlled object's monitoring and status signals.
The function generates general time-stamped ON/OFF events to the common event buffer from each
of the two (2) output signal as well as from several operational event signals. The time stamp resolution
is 1 ms. The function also a resettable cumulative counter for each of the applied reclosing events and
requests.
The auto-recloser function can be divided into the starter, shot selector state machine, sorter and shot
blocks which operate dynamically during the recloser sequences according to the given settings and
input signal monitoring. The behavior of the function can be changed even during sequences that are
based on programmed reclosing schemes and on active requests.
A
AQ
Q-S215
-S215
Instruction manual
Version: 2.04
153
Summary of Contents for AQ-S215
Page 1: ...AQ S215 Bay control IED Instruction manual...
Page 249: ...Figure 7 4 151 Example block scheme A AQ Q S215 S215 Instruction manual Version 2 04 248...
Page 269: ...Figure 8 13 172 Device installation A AQ Q S215 S215 Instruction manual Version 2 04 268...
Page 287: ...10 Ordering information A AQ Q S215 S215 Instruction manual Version 2 04 286...
