Areva MiCOM P441, Техническое руководство

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Application Notes P44x/EN AP/E33
MiCOM P441/P442 & P444 Page 149/220
V>Live Bus
(See Checksync logic description – section 4.4.5.2)
Ctrl Cls In Prog
Manual close in progress-using CB control (timer manual closing delay in progress)
Control Trip
CB Trip command by internal CB control
Control Close
CB close command by internal CB control
4.5.8 Setting Guidelines
Should autoreclosure not be required, the function may be Disabled in the relay
Configuration menu. Disabling the autorecloser does not prevent the use of the internal
check synchronism element to supervise manual circuit breaker closing. If the autoreclose
function is Enabled, the setting guidelines now outlined should be read:
4.5.9 Choice of Protection Elements to Initiate Autoreclosure
In most applications, there will be a requirement to reclose for certain types of faults but not
for others. The logic is partly fixed so that autoreclosure is always blocked for any Switch on
to Fault, Stub Bus Protection, Broken Conductor or Zone 4 trip. Autoreclosure will also be
blocked when relay supervision functions detect a Circuit Breaker Failure or Voltage
Transformer/Fuse Failure. All other protection trips will initiate autoreclosure unless blocking
bits are set in the A/R Block function links. Setting the relevant bit to 1 will block
autoreclose initiation (forcing a three pole lockout), setting bits to zero will allow the set
autoreclose cycle to proceed.
When autoreclosure is not required for multiphase faults, DDB signals 2Ph Fault and 3Ph
Fault can be mapped via the PSL in a logical OR combination onto input DDB: BAR. When
blocking is only required for a three phase fault, the DDB signal 3Ph Fault is mapped to BAR
alone. Three phase faults are more likely to be persistent, so many utilities may not wish to
initiate autoreclose in such instances.
4.5.10 Number of Shots
There are no clear-cut rules for defining the number of shots for any particular application. In
order to determine the required number of shots the following factors must be taken into
account:
An important consideration is the ability of the circuit breaker to perform several trip close
operations in quick succession and the effect of these operations on the maintenance period.
The fact that 80 - 90% of faults are transient highlights the advantage of single shot
schemes. If statistical information for the power system shows that a moderate percentage
of faults are semi-permanent, further DAR shots may be used provided that system stability
is not threatened. Note that DAR shots will always be three pole.