Hitachi Relion 670 Series Commissioning Manual page 181

1MRK 511 403-UEN Rev. L
4. Review the settings for UDeadband (based on percentage of nominal bus voltage) and
calculate the upper (U2) and lower (U1) voltage regulation limits for which a tap change
command will be issued from the master transformer in the group.
5. Review the expected time for first (t1) and subsequent (t2) tap change commands from the
master transformer in the local HMI under Main menu/Settings /IED Settings/Control /
TransformerVoltageControl(90, U↕)/TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /Time/t1 and
t2
6. Apply a voltage 1% below U1 and wait for the issue of a raise command from the voltage
control after the expiry of a constant or inverse time delay set by t1. Detection of this command
will involve locating the allocated binary output for a raise command in the Signal Matrix in
PCM600 and monitoring a positive from this output. Confirm the timing of this command
correlates with the setting t1.
7. After the issue of the raise command, confirm that all follower transformers in the group change
tap in accordance with the command issued from the master transformer.
8. Inject a voltage U
and wait for the issue of a lower command from the voltage control after the expiry of a
constant or inverse time delay set by t2.
9. Confirm that all follower transformers in the group change tap in accordance with this
command.
Circulating current voltage regulation
This instruction for confirmation of circulating current voltage regulation assumes two transformers in
the parallel group. Setting confirmation through secondary injection requires calculation of circulating
currents for each transformer based on impedance values and respective compensating factors, and
is therefore more complex for greater than two transformers.
1. Confirm that OperationPAR is set to CC for the transformers in the parallel group.
2. For parallel operation, it is also recommended that settings be confirmed for parallel group
membership, governed by setting TnRXOP in the local HMI under Main menu/Settings /IED
Settings/Control /TransformerVoltageControl(90, U↕)/TR8ATCC(90, U↕||):x/ParCtrl
The general parallel arrangement of transformers are defined by setting TnRXOP to On or Off.
The following rules are applicable on the settings T1RXOP - T4RXOP.
If IED T1 and T2 are connected,
•
•
If T1 - T3 are available,
•
•
3. Review the settings for UDeadband (based on percentage of nominal bus voltage) and
calculate the upper (U2) and lower (U1) voltage regulation limits for which a tap change
command will be issued from the master transformer in the group.
4. Review the expected time for first (t1) and subsequent (t2) tap change commands from the
master transformer in the local HMI under Main menu/Settings /IED Settings/
TransformerVoltageControl(90, U↕) /TR1ATCC(90, U↕):x/TR8ATCC(90, U↕||):x /Time/t1 and
t2
5. Inject a voltage U
6. Inject a load current for Transformer 1 that is equal to rated load current I2Base and a load
current for Transformer 2 that is equal to 95% of rated load current I2Base. This will have the
effect of producing a calculated circulating current that flows from HV to LV side for Transformer
1 and LV to HV side for Transformer 2.
7. Confirm that a circulating current is measured on the local HMI that is equal in magnitude to 5%
of I2Base, with polarity as discussed in step 6.
Bay control REC670
Commissioning manual
for the master transformer that is 1% above the upper deadband limit U2
B
T1RXOP shall be set to On in instance 2 of TR8ATCC, and
T2RXOP shall be set to On in instance 1 of TR8ATCC.
T1RXOP and T2RXOP shall be set to On in instance 3 of TR8ATCC,
T2RXOP and T3RXOP shall be set to On in instance 1 of TR8ATCC and so on.
The parameter corresponding to the own IED must not be set. T1RXOP should
thus not be set in IED T1, T2RXOPnot in IED T2 and so on.
equal to USet for each transformer.
B
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Section 11
Testing functionality by secondary injection
SEMOD175185-775 v8
175