Hitachi Relion 670 Series Applications Manual page 214

Section 12
Control
The setting CloseAngleMax is the maximum closing angle between bus and line at which
synchronizing is accepted. To minimize the moment stress when synchronizing near a power station,
a narrower limit should be used. A typical value is 15 degrees.
tBreaker
The tBreaker shall be set to match the closing time for the circuit breaker and should also include the
possible auxiliary relays in the closing circuit. It is important to check that no slow logic function
blocks (e.g. in 100ms loop) are used in the configuration of the IED as there then can be big
variations in closing time due to those components. Typical setting is 80-150 ms depending on the
breaker closing time.
tClosePulse
The setting for the duration of the breaker close pulse.
tMaxSynch
The setting tMaxSynch is set to reset the operation of the synchronizing function if the operation
does not take place within this time. The setting must allow for the setting of FreqDiffMin, which will
decide how long it will take maximum to reach phase equality. At the setting of 10 mHz, the beat time
is 100 seconds and the setting would thus need to be at least tMinSynch plus 100 seconds. If the
network frequencies are expected to be outside the limits from the start, a margin needs to be added.
A typical setting is 600 seconds.
tMinSynch
The setting tMinSynch is set to limit the minimum time at which the synchronizing closing attempt is
given. The synchronizing function will not give a closing command within this time, from when the
synchronizing is started, even if a synchronizing condition is fulfilled. A typical setting is 200 ms.
Synchrocheck settings
OperationSC
The OperationSC setting Off disables the synchrocheck function and sets the outputs AUTOSYOK,
MANSYOK, TSTAUTSY and TSTMANSY to low. With the setting On, the function is in the service
mode and the output signal depends on the input conditions.
UHighBusSC and UHighLineSC
The voltage level settings must be chosen in relation to the bus or line network voltage. The
threshold voltages UHighBusSC and UHighLineSC have to be set lower than the value at which the
breaker is expected to close with the synchronism check. A typical value can be 80% of the base
voltages.
UDiffSC
The setting for voltage difference between line and bus in p.u. This setting in p.u. is defined as (U-
Bus/GblBaseSelBus) - (U-Line/GblBaseSelLine). A normal setting is 0,10-0,15 p.u.
FreqDiffM and FreqDiffA
The frequency difference level settings, FreqDiffM and FreqDiffA, shall be chosen depending on the
condition in the network. At steady conditions a low frequency difference setting is needed, where the
FreqDiffM setting is used. For autoreclosing a bigger frequency difference setting is preferable,
where the FreqDiffA setting is used. A typical value for FreqDiffM can be10 mHz, and a typical value
for FreqDiffA can be 100-200 mHz.
PhaseDiffM and PhaseDiffA
208
© 2017 - 2023 Hitachi Energy. All rights reserved
1MRK506375-UEN Rev. N
Railway application RER670
Application manual